HVO Kilauea Status

Recent Kilauea Status Reports, Updates, and Information Releases

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Wednesday, October 22, 2014 9:39 AM HST (Wednesday, October 22, 2014 19:39 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. There was no significant change in ground tilt at the summit, and there was no no net change in lava lake level. At the East Rift Zone, Civil Defense observed this morning that the lobe on the southeast side of the June 27th flow advanced about 90 meters (100 yards) since yesterday and overtook the former leading tip of the flow. The former tip also advanced, but only by about 20 m (25 yd). All flow activity remains approximately 0.6 miles from Apa’a St/Cemetery Rd.

June 27th Lava Flow Observations: A Civil Defense overflight this morning found that the breakout that has been advancing about 80 m (90 yd) per day along the southeast edge of the flow since early last week has overtaken the former leading edge of the flow. The former flow tip also advanced about 20 m (25 yd). Civil Defense reports little burning, however, south winds were carrying smoke and vog to lower Puna and Hilo. HVO geologists will conduct investigations of the leading edges of the flow on foot today.

Puʻu ʻŌʻō Observations: Over the past 24 hours, instruments at Puʻu ʻŌʻō did not record any significant net change in ground tilt nor seismic tremor. Glow was visible overnight above several out gassing openings in the crater floor, but there were no significant changes in activity within the crater. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: There was no significant change in ground tilt over the past day. The lava lake level fluctuated slightly during the last day, as usual, but stayed around 60 meters below the rim of the Overlook crater (the floor of Halemaʻumaʻu).

Seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers in the summit area have recorded slight contraction across the caldera since early July, but no significant change in elevation during that time. The most recent sulfur-dioxide emission rate measurements for the summit were 2,900–6,500 tonnes/day (see caveat below) for the week ending October 14, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Tuesday, October 21, 2014 7:27 AM HST (Tuesday, October 21, 2014 17:27 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. There was no significant change in ground tilt at the summit, and the lava lake level fluctuated in typical fashion. At the middle East Rift Zone, the June 27th lava flow moved no closer to Pāhoa, but a narrow lobe was about to overtake the tip of the flow. Active breakouts were scattered across the flow upslope from the front, and one active finger continued to advance about mid-way along the length of the flow.

June 27th Lava Flow Observations: A Hawaiian Volcano Observatory overflight yesterday afternoon found that the flow had moved no closer to Apaʻa St/Cemetery Rd over the weekend, but the flow front had widened and small breakouts were scattered across the flow from right at the front up to about 2 km (1.2 mi) upslope. One of these breakouts was a narrow lobe that has been advancing along the southeast edge of the flow since early last week, moving about 80 m (90 yd) per day on average. This lobe was a day or two away from overtaking the tip of the flow, if it keeps moving.

The only other breakouts observed on the flow were mid-way along its length, in the area where lava first entered cracks on August 18. There, activity was relatively weak and was focused along a narrow finger of lava has been moving toward the east within a shallow graben for the last few weeks. It intersected an older part of the flow within the crack system over the weekend. No other active surface flows were observed in this area.

Puʻu ʻŌʻō Observations: No significant change in eruptive activity or ground tilt was recorded at Puʻu ʻŌʻō over the past 24 hours. Seismic tremor remained low and relatively constant. Glow was visible overnight above several outgassing openings in the crater floor. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: There was no significant change in ground tilt over the past day. The lava lake fluctuated between about 55 and 65 m (180–215 ft) below the rim of the Overlook crater (the floor of Halemaʻumaʻu) in response to variations in spattering on the lake surface.

There was no significant change in seismicity beneath Kīlauea over the past day. Seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 2,900–6,500 tonnes/day (see caveat below) for the week ending October 14, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WARNING

Current Aviation Color Code: ORANGE

Issued: Monday, October 20, 2014, 7:45 PM HST (20141021/0545Z)
Source: Hawaiian Volcano Observatory
Notice Number: 2014/H19
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: HI Hawaii and Pacific Ocean

Volcanic Activity Summary: The June 27th flow remains active. The flow front has not advanced downslope since October 17, but there are several breakouts within about 1.3 km (0.8 mi) upslope of the front. Along the south side of the flow, a narrow breakout has moved about 80 m/day in the past week, and could overtake the distal tip of the flow in the next couple of days. The flow front remains about 1.4 km (0.9 mi) upslope from Apa`a St. along the steepest descent path and 1.1 km (0.7 mi) upslope from Apa`a St. along a straight line. Lava discharge from Pu‘u ‘Ō‘ō into the June 27th lava tube remains low. Because the flow has not advanced in the past few days, we do not offer a future projection of the flow's advance.

Pāhoa town is in the Puna District of the County of Hawai`i.


Recent Observations:
[Lava flow] The June 27th lava flow has not advanced since October 17. The leading edge remains about 1.1 km (0.7 mi) straight-line distance from Apa`a St.

Hazard Analysis:
[Lava flow] The June 27th lava flow from the Pu‘u ‘Ō‘ō vent is active, with several breakouts within 1.3 km (0.8 mi) upslope of the stalled flow front.

Remarks: The Pu‘u ‘Ō‘ō vent in the East Rift Zone of Kīlauea Volcano began erupting on January 3, 1983, and has continued erupting for more than 31 years, with the majority of lava flows advancing to the south. Over the past two years, lava flows have issued from the vent toward the northeast. The June 27th flow is the most recent of these flows and the first to threaten a residential area since 2010-2011. On June 27, 2014, new vents opened on the northeast flank of the Pu‘u ‘Ō‘ō cone and fed a narrow lava flow to the east-northeast. On August 18, the flow entered a ground crack, traveled underground for several days, then resurfaced to form a small lava pad. This sequence was repeated three more times over the following days with lava entering and filling other cracks before reappearing at the surface, in two of the cases farther downslope. Lava emerged from the last crack on September 6, forming a surface flow that initially moved to the north, then to the northeast, at a rate of 400 m/day (437 yd). The flow slowed thereafter and, between September 12 and 19, the rate of advancement varied, averaging 225 m/day (246 yd). The flow front stalled by September 22, but new breakouts upslope overtook the stalled front on September 29. During the past 2 weeks, advance rates of the flow front have slowed from 120 m/day (131 yd) to less than 25 m/day (27 yd).

Contacts: HVO media contact
askHVO@usgs.gov


Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While this VAN is in effect, regularly scheduled updates are posted at http://hvo.wr.usgs.gov/activity/kilaueastatus.php

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Monday, October 20, 2014 8:57 AM HST (Monday, October 20, 2014 18:57 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. There was a small amount of net deflation at the summit, and the lava lake fell slightly before leveling off. At the middle East Rift Zone, the June 27th flow remains active but moved no closer to Pāhoa. Active breakouts are scattered across the flow near its front and about mid-way along its length.

June 27th Lava Flow Observations: A Civil Defense overflight this morning found no advancement at the front of the flow, though breakouts remain active immediately upslope. The stalled front is about 1.3 km (0.8 miles) from Apaʻa St/Cemetery Rd, as measured along the steepest-descent line that the flow has been following.

Puʻu ʻŌʻō Observations: No significant change in eruptive activity or ground tilt was recorded at Puʻu ʻŌʻō over the past 24 hours. Seismic tremor has been low and relatively constant. Glow was visible overnight above several outgassing openings in the crater floor. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: The summit gradually deflated until late yesterday morning. After that, the summit tiltmeter recorded only tiny fluctuations indicating no significant inflation or deflation. The lava lake level fell slightly with the deflation, and then fluctuated between about 60 and 65 m (200–215 ft) below the rim of the Overlook crater (the floor of Halemaʻumaʻu) thereafter, the superficial changes in level caused by variations in spattering on the lake surface.

A visit to Halemaʻumaʻu yesterday to measure lava level discovered fresh spatter (scoria) scattered sparsely around the closed visitor overlook. A review of webcam imagery and seismicity found that a small explosive event occurred yesterday morning (October 19) from the lake surface out of sight below the webcams just after 1 AM. This is a reminder that potentially life-threatening explosive events are still occasionally occurring and happen without warning.

There was no significant change in seismicity beneath Kīlauea over the past day. Seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 3,600–5,200 tonnes/day (see caveat below) for the week ending September 30, 2014. A small amount of particulate material was carried aloft by the plume, in addition to the sparse scoria deposited by yesterday morning's explosive event.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Sunday, October 19, 2014 9:03 AM HST (Sunday, October 19, 2014 19:03 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. Slow inflation at the summit switched to deflation early this morning, and the summit lava lake was at a relatively steady level. At the middle East Rift Zone, the June 27th flow remains active, with breakouts scattered near its front and about mid-way along its length.

June 27th Lava Flow Observations: Glow from the June 27th flow was visible overnight via webcam, indicating that the flow remains active near its front and mid-way along its length. A Civil Defense overflight yesterday morning found no significant flow advancement, and the distal tip of the flow was still about 1.3 km (0.8 miles) from Apaʻa St/Cemetery Rd, as measured along the steepest-descent line that the flow has been following.

Puʻu ʻŌʻō Observations: No significant change in eruptive activity was recorded at Puʻu ʻŌʻō over the past day. Variations in ground tilt recorded by the tiltmeter at Puʻu ʻŌʻō were primarily caused by heavy rainfall. Seismic tremor has been low and relatively constant. Glow was visible overnight above several outgassing openings in the crater floor. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: Gradual inflation switched to deflation at about 3 AM this morning. The lava lake level was relatively steady, generally fluctuating between about 55 and 60 m (180-200 ft) below the rim of the Overlook crater (the floor of Halemaʻumaʻu) in response to variations in spattering on the lake surface. A huge slice of the inner ledge of juvenile lava, frozen onto the wall of the Overlook crater around the lava lake, collapsed into the lake at about 0630 AM this morning, causing several minutes of intense, low-level spattering around the lake margin.

A cluster of small seismic events occurred at a shallow level beneath Kīlauea's upper East Rift Zone at about the time that ground tilt switched from inflation to deflation. Such behavior is fairly common. Seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 3,600–5,200 tonnes/day (see caveat below) for the week ending September 30, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Saturday, October 18, 2014 9:24 AM HST (Saturday, October 18, 2014 19:24 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. There was slow inflation at the summit over the past day, and the summit lava lake was at a relatively steady level. At the middle East Rift Zone, the June 27th flow remains active, though at a relatively low level, with most breakouts scattered from the front to about 2 km (1.2 miles) upslope.

June 27th Lava Flow Observations: Webcams monitoring the June 27th flow recorded incandescence during the few sporadic breaks in the weather that occurred overnight, indicating that the flow remains active. When the flow was observed yesterday morning (October 17), the barely active flow front was about 1.3 km (0.8 miles) from Apaʻa St/Cemetery Rd, as measured along the steepest-descent line that the flow has been following, and small breakouts were scattered across the surface of the flow up to about 2 km (1.2 miles) upslope from the front. The amount of lava flowing through the tube system was found to be at the lowest level measured so far for this flow. Though the flow was not directly observed this morning, we expect little change to have occurred overnight, especially given the lack of any significant geophysical changes.

Puʻu ʻŌʻō Observations: No significant change in eruptive activity was recorded at Puʻu ʻŌʻō over the past day. An inflationary tilt signal caused by heavy rainfall dominates the tiltmeter record. Seismic tremor has been low and relatively constant. Glow was visible during breaks in the weather overnight above several outgassing openings in the crater floor. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: The summit inflated slowly over the past day, and the lava lake level was around 60 m (200 ft) below the rim of the Overlook crater (the floor of Halemaʻumaʻu) during that period, with small fluctuations caused by variations in spattering on the lake surface.

Deep tremor south of Pāhala, which had been recorded over the past week, was not recorded over the past day. Otherwise, there were no significant changes in seismicity beneath Kīlauea in the past 24 hours, and seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 3,600–5,200 tonnes/day (see caveat below) for the week ending September 30, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WARNING

Current Aviation Color Code: ORANGE

Issued: Friday, October 17, 2014, 5:42 PM HST (20141018/0342Z)
Source: Hawaiian Volcano Observatory
Notice Number: 2014/H18
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: HI Hawaii and Pacific Ocean

Volcanic Activity Summary: The June 27th flow remains active. The flow front advanced downslope about 50 m (55 yd) in the past 2 days. During an overflight this morning lava breakouts were observed on the surface and margins of the flow as far as 2 km (1.2 mi) upslope, and they continue to widen the flow. The flow front remains about 1.4 km (0.9 mi) upslope from Apa`a St. along the steepest descent path and 1.1 km (0.7 mi) upslope from Apa`a St. along a straight line. Lava discharge from Pu‘u ‘Ō‘ō into the June 27th lava tube was low when measured this morning. Because the flow has slowed to about 25 m/day (27 yd), we do not offer a future projection of the flow's advance. Our next overflight is scheduled for Monday morning.

Pāhoa town is in the Puna District of the County of Hawai`i.


Recent Observations:
[Lava flow] The June 27th lava flow has advanced at an average rate of 39 m/day (43 yd) since October 10. The leading edge remains about 1.1 km (0.7 mi) straight-line distance from Apa`a St.

Hazard Analysis:
[Lava flow] The June 27th lava flow from the Pu‘u ‘Ō‘ō vent is active, and lava is being supplied to the flow front, which is slowly advancing downslope toward Pāhoa.

Remarks: The Pu‘u ‘Ō‘ō vent in the East Rift Zone of Kīlauea Volcano began erupting on January 3, 1983, and has continued erupting for more than 31 years, with the majority of lava flows advancing to the south. Over the past two years, lava flows have issued from the vent toward the northeast. The June 27th flow is the most recent of these flows and the first to threaten a residential area since 2010-2011. On June 27, 2014, new vents opened on the northeast flank of the Pu‘u ‘Ō‘ō cone and fed a narrow lava flow to the east-northeast. On August 18, the flow entered a ground crack, traveled underground for several days, then resurfaced to form a small lava pad. This sequence was repeated three more times over the following days with lava entering and filling other cracks before reappearing at the surface, in two of the cases farther downslope. Lava emerged from the last crack on September 6, forming a surface flow that initially moved to the north, then to the northeast, at a rate of 400 m/day (437 yd). The flow slowed thereafter and, between September 12 and 19, the rate of advancement varied, averaging 225 m/day (246 yd). The flow front stalled by September 22, but new breakouts upslope overtook the stalled front on September 29. During the past 2 weeks, advance rates of the flow front have slowed from 120 m/day (131 yd) to 25 m/day (27 yd).

Contacts: HVO media contact
askHVO@usgs.gov


Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While this VAN is in effect, regularly scheduled updates are posted at http://hvo.wr.usgs.gov/activity/kilaueastatus.php

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Friday, October 17, 2014 10:13 AM HST (Friday, October 17, 2014 20:13 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. At the summit, there was no significant change or trend in ground tilt in the past day, and the summit lava lake remained steady. At the middle East Rift Zone, the front of the June 27th flow remains active, with breakouts scattered across the flow upslope from the front.

June 27th Lava Flow Observations: The June 27th lava flow remains active. This morning's overflight determined that the flow front advanced only about 50 m (55 yd) since October 15. Small breakouts are scattered across the surface and along the edges of the flow as far as about 2 km (1.2 miles) upslope of the front. The breakouts are widening the overall flow; flow width is 600 m (655 yd) about 1.3 km (0.8 mi) upslope. The flow front is still about 1.3 km (0.8 miles) from Apaʻa St/Cemetery Rd, as measured along the steepest-descent line that the flow has been following.

A few breakouts are also active roughly mid-way along the length of the flow, just upslope from the area where lava enters and travels within ground cracks. One such breakout advanced eastward 215 m (235 yd) in the past 2 days to form a narrow flow about 35 m (38 yd) wide parallel to the crack system. Breakouts have persisted in this area for several weeks, but the number of breakouts and overall level of activity has fallen over the past week.

Puʻu ʻŌʻō Observations: No significant change in eruptive activity or ground tilt was recorded at Puʻu ʻŌʻō over the past day. Seismic tremor has been low and relatively constant. Glow was visible overnight above several outgassing openings in the crater floor. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: A very slight inflationary trend of the summit has occurred since yesterday morning. The lava lake level yesterday afternoon was 64-65 m below the rim of the Overlook crater (the floor of Halemaʻumaʻu).

There has been an increase in deep tremor south of Pāhala over the past week. This is a common source area for tremor, and is associated with the deepest root of Kīlauea's plumbing system. It is not related to the recent magnitude 4.0 earthquake near Nāʻālehu, and past occurrences of tremor in this area have not been correlated with changes in Kīlauea's eruptive activity.

There were no significant changes in seismicity elsewhere beneath Kīlauea over the past day, and seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 3,600–5,200 tonnes/day (see caveat below) for the week ending September 30, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Thursday, October 16, 2014 9:39 AM HST (Thursday, October 16, 2014 19:39 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. At the summit, deflationary ground tilt switched to inflation, and the summit lava lake level fell. At the middle East Rift Zone, the front of the June 27th flow has stalled, but the flow is still active, with breakouts scattered across the flow upslope from the front.

June 27th Lava Flow Observations:The June 27th lava flow remains active, but the flow front has stalled. Small breakouts, however, remain scattered across the surface and along the edges of the flow up to about 2 km (1.2 miles) back from the front. The flow width ranges from 200 to 500 m (220 to 550 yards) over this distance. Most breakouts were found within this part of the flow during an overflight yesterday morning (October 15). The flow front at that time was about 1.3 km (0.8 miles) from Apaʻa St/Cemetery Rd, as measured along the steepest-descent line that the flow has been following.

Breakouts are also active roughly mid-way along the length of the flow, just upslope from the area where lava enters and travels within ground cracks. Breakouts have persisted in this area for several weeks, but the number of breakouts and overall level of activity has fallen over the past week.

Puʻu ʻŌʻō Observations: No significant change in eruptive activity or ground tilt was recorded at Puʻu ʻŌʻō over the past day. Seismic tremor has been low and relatively constant. Glow was visible overnight above several outgassing openings in the crater floor. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014.

Summit Observations: Deflation of the summit slowed through the day yesterday and overnight, and switched to slow inflation shortly before sunrise this morning. The lava lake level fell with the deflation to roughly 65 m below the rim of the Overlook crater (the floor of Halemaʻumaʻu), where it remains this morning.

There has been an increase in deep tremor south of Pāhala over the past week. This is a common source area for tremor, and is associated with the deepest root of Kīlauea's plumbing system. It is not related to the recent magnitude 4.0 earthquake near Nāʻālehu, and past occurrences of tremor in this area have not been correlated with changes in Kīlauea's eruptive activity.

There were no significant changes in seismicity elsewhere beneath Kīlauea over the past day, and seismic tremor beneath the summit remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 3,600–5,200 tonnes/day (see caveat below) for the week ending September 30, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow advanced to the northeast, confined to old grounds cracks for part of its length, and has been slowly approaching the town of Pāhoa.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WARNING

Current Aviation Color Code: ORANGE

Issued: Wednesday, October 15, 2014, 5:28 PM HST (20141016/0328Z)
Source: Hawaiian Volcano Observatory
Notice Number: 2014/H17
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: HI Hawaii and Pacific Ocean

Volcanic Activity Summary: The June 27th flow remains active, with the flow front having advanced downslope about 50 m (55 yd) since October 13. Breakouts as far as 1.8 km (1.1 mi) upslope widened the flow by as much as 100 m (109 yd) in the past 2 days. The flow front remains about 1.4 km (0.9 mi) upslope from Apa`a St. along the steepest descent path and 1.1 km (0.7 mi) upslope from Apa`a St. along a straight line. Because the flow has slowed in the past 2 days to about 25 m/day (27 yd), we do not offer a future projection of the flow's advance. Our next overflight is scheduled for Friday morning, but Tropical Storm Ana may ground the flight.

Pāhoa town is in the Puna District of the County of Hawai`i.


Recent Observations:
[Lava flow] The June 27th lava flow has advanced at an average rate of 49 m/day (54 yd) since October 8. The leading edge is now about 1.1 km (0.7 mi) straight-line distance from Apa`a St.

Hazard Analysis:
[Lava flow] The June 27th lava flow from the Pu‘u ‘Ō‘ō vent is active, and lava is being supplied to the flow front, which is slowly advancing downslope toward Pāhoa.

Remarks: The Pu‘u ‘Ō‘ō vent in the East Rift Zone of Kīlauea Volcano began erupting on January 3, 1983, and has continued erupting for more than 31 years, with the majority of lava flows advancing to the south. Over the past two years, lava flows have issued from the vent toward the northeast. The June 27th flow is the most recent of these flows and the first to threaten a residential area since 2010-2011. On June 27, 2014, new vents opened on the northeast flank of the Pu‘u ‘Ō‘ō cone and fed a narrow lava flow to the east-northeast. On August 18, the flow entered a ground crack, traveled underground for several days, then resurfaced to form a small lava pad. This sequence was repeated three more times over the following days with lava entering and filling other cracks before reappearing at the surface, in two of the cases farther downslope. Lava emerged from the last crack on September 6, forming a surface flow that initially moved to the north, then to the northeast, at a rate of 400 m/day (437 yd). The flow slowed thereafter and, between September 12 and 19, the rate of advancement varied, averaging 225 m/day (246 yd). The flow front stalled by September 22, but new breakouts upslope overtook the stalled front on September 29. During the past 2 weeks, advance rates of the flow front have varied between about 120 m/day (131 yd) and 25 m/day (27 yd).

Contacts: HVO media contact
askHVO@usgs.gov


Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While this VAN is in effect, regularly scheduled updates are posted at http://hvo.wr.usgs.gov/activity/kilaueastatus.php

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Wednesday, October 15, 2014 8:44 AM HST (Wednesday, October 15, 2014 18:44 UTC)


This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available at http://hvo.wr.usgs.gov/activity/kilaueastatus.php), was prepared by the USGS Hawaiian Volcano Observatory (HVO). All times are Hawai`i Standard Time.

KILAUEA VOLCANO (VNUM #332010)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WARNING
Current Aviation Color Code: ORANGE

Activity Summary: Kīlauea continued to erupt at its summit and within the East Rift Zone, and gas emissions remained elevated. At the summit, deflationary ground tilt occurred over the past day, and the summit lava lake level has been fairly stable. This morning's Civil Defense overflight observed that the June 27th flow along the East Rift Zone remains active and has advanced approximately 23 m (25 yd) toward the northeast since yesterday. Vegetation is burning along the edges of the flow.

June 27th Lava Flow Observations:Activity along the June 27th lava flow continues, with lava moving through the tube from Puʻu ʻŌʻō to the flow front. This morning's Civil Defense overflight observed continued activity at the flow front, but with only a small amount of advancement (23 m, or 25 yards) since yesterday. Civil Defense reports the flow front this morning was approximately 1 km (0.6 miles) from Apa`a St. Breakouts have also been scattered a short distance behind the flow front, as well as midway along the length of the flow where lava first entered the crack system. Vegetation in direct contact with the flow is burning. An HVO overflight is scheduled for this morning.

Puʻu ʻŌʻō Observations: No significant change in tilt was recorded at Puʻu ʻŌʻō over the past day. Glow was visible overnight above several outgassing openings in the crater floor, but there were no significant changes in activity within the crater over the past day. The most recent sulfur-dioxide emission-rate measurement for the East Rift Zone was 450 tonnes per day (from all sources) on October 9, 2014. Seismic tremor has been low and constant.

Summit Observations: There was deflationary ground tilt at the summit over the past day, with steeper deflation starting around 4 am this morning. The lava lake level within the Overlook crater is fairly stable. There was no major change in seismicity on Kīlauea over the past day. Seismic tremor remained low and varied with changes in spattering on the surface of the lava lake. GPS receivers spanning the summit caldera recorded about 5 cm (2 in) of extension between early May and early July. Since then, little significant extension or contraction has occurred. The most recent sulfur-dioxide emission rate measurements for the summit were 3,600–5,200 tonnes/day (see caveat below) for the week ending September 30, 2014. A small amount of particulate material was carried aloft by the plume.



Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207

Background:
Summit The summit lava lake is within an elliptical crater (unofficially called the Overlook crater), which has dimensions of approximately 160 m (520 ft) by 210 m (690 ft), inset within the eastern portion of Halemaʻumaʻu Crater. The lake level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halemaʻumaʻu Crater. The Overlook crater has been more-or-less continuously active since it opened during a small explosive event on March 19, 2008. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation. Since 2013, the lava level has been typically between 30 m (100 ft) and 60 m (200 ft) below the floor of Halemaʻumaʻu Crater. Small collapses in the Overlook crater are common, and over time have resulted in a gradual enlargement of the Overlook crater. The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake). The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.

East Rift Zone vents and flow field The eruption in Kīlauea's middle East Rift Zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Puʻu ʻŌʻō Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Puʻu ʻŌʻō Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawaiʻi Volcanoes National Park in early December 2011. The flows stalled and re-entered the ocean starting on November 24, 2012, until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. The Kahaualeʻa flow, which started from the spatter cone/lava lake at the northeast edge of the Puʻu ʻŌʻō crater floor in mid-January 2013 was dead by late April, but a new flow (informally called Kahaualeʻa 2) became active in the same area in early May 2013, waxing with inflation and waning with deflation. The Kahaualeʻa 2 flow died following the onset of a new breakout from the northeast flank of Puʻu ʻŌʻō on June 27, 2014. The June 27th flow continues to advance toward the northeast.

Hazard Summary:
East Rift Zone vents and flow field Lava flows from the June 27 breakout pose no immediate threat to residential areas. Near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume. In addition, potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. Active lava flows within forested areas can produce methane blasts capable of propelling rocks and other debris into the air. All recently active lava flows are within Hawaiʻi Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs.

Kīlauea Crater Ash and Pele's hair can be carried several kilometers downwind, and potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary:
East Rift Zone flow field The June 27th lava flow is currently within the Kahaualeʻa Natural Area Reserve, which has been closed by the Hawaii State Department of Natural Land and Resources (DLNR) due to the ongoing volcanic hazards (http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/kahaualea/), and the Wao Kele o Puna Forest Reserve, also closed by DLNR and the Office of Hawaiian Affairs (http://dlnr.hawaii.gov/blog/2014/09/12/nr14-113/). According to the Hawaii County Civil Defense website (http://www.hawaiicounty.gov/active-alerts/): "The public is reminded that the flow is not visible and cannot be accessed from any public areas."

Puʻu ʻŌʻō Cone and Kīlauea Crater These areas are within Hawaiʻi Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Definitions of Terms Used:

ash: tephra less than 2 mm (5/64 inches) in size.

CD: Hawai`i County Civil Defense

composite seismic events: is a seismic signal with multiple distinct phases that has been recorded frequently at HVO from the Halema`uma`u Overlook vent area since its explosive opening in March, 2008. For the composite events recorded at Halema`uma`u, we typically see an initial high frequency vibration lasting for a few seconds that have been correlated with rockfalls. This is followed by about 30 seconds of a long-period (LP) oscillation with an approximately 2- to 3-second period. The final phase of the signal is several minutes of a very-long-period (VLP) oscillation with an approximately 25- to 30-second period. The LP signals are interpreted to be from the uppermost portion of the conduit and VLP signals are interpreted to be fluid passing through a deep constriction in the conduit through which lava rises to the pond surface we see in the webcam.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a geophysical event of uncertain volcanic significance. DI events are recorded by tiltmeters at Kilauea summit as an abrupt deflation of up to a few microradians in magnitude lasting several hours (weak DI events) to 2-3 days (strong DI events) followed by an abrupt inflation of approximately equal magnitude. The tilt events are usually accompanied by an increase in summit tremor during the deflation phase. A careful analysis of these events suggests that they may be related to changes in magma supply to a storage reservoir at less than 1 km depth, just east of Halema`uma`u crater. Usually, though not always, these changes propagate through the magma conduit from the summit to the east rift eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o delayed by several hours. DI events often correlate with lava pulses and/or pauses in the eruption at the Pu`u `O`o/Peace Day vents.

glow: light from an unseen source; indirect light.

Halema`uma`u Overlook vent: has been difficult to describe concisely. The vent is actually a pit, or crater, in the floor of the larger Halema`uma`u Crater which is, in turn, in the floor of the larger Kilauea caldera or crater - a crater within a crater within a crater. It is easiest to describe as a pit inset within the floor of a crater within a caldera. The pit is about 160 m (525 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at a depth of 200 m (660 ft) below the Halema`uma`u Crater floor. From November, 2009, to now, a lava pond surface has been visible in this pit.

incandescence: the production of visible light from a hot surface. The term also refers to the light emitted from a hot surface. The color of the light is related to surface temperature. Some surfaces can display dull red incandescence at temperatures as low as 430 degrees Centigrade (806 degrees Fahrenheit). By contrast, molten lava displays bright orange to orange-yellow light from surfaces that are hotter than 900 degrees C (1,650 degrees F).

LPs: - Long Period (LP) events refer to earthquakes that have a lower frequency or tone than typical earthquakes and are usually attributed to the resonance of fluid- and gas-filled conduits, cracks and/or chambers. Because of their association with fluids and gases, LP earthquakes in the vicinity of volcanoes can be useful for monitoring purposes. At other volcanoes LP earthquakes are also known as low-frequency earthquakes, tornillos or B-type earthquakes.

mauka, makai: Hawaiian terms for directions relative to the coast - makai or ma kai (toward the coast) and mauka or ma uka (toward the highlands or away from the coast).

microradian: a measure of angle equivalent to 0.000057 degrees.

pali: Hawaiian term for cliff or precipice.

rise/fall events: one of the episodic behaviors exhibited by the summit lava lake starting in 2009. An event starts with a rise in lava level, a decrease in high-frequency summit tremor amplitude, a decrease or total stoppage of spattering, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level amidst resumed vigorous spattering, seismic tremor amplitude will increase for a short time (a seismic tremor burst) before resuming background levels, and summit tilt will return to its previous level. Gas emissions decrease significantly during the high lava stand (the plume gets wispy), and resume during its draining phase. Taken together, the geophysical characteristics suggest that, during the high lava stand, lava is puffed up with gas trapped under the lava lake crust.

seismic tremor dropout: these behaviors are identical to rise/fall events except that the lava lake level doesn't rise or fall significantly. High-frequency seismic tremor, gas emissions, and spattering decrease abruptly during a dropout. A dropout can end with a burst of seismic tremor and a significant pulse of gas emissions.

tephra: all material deposited by fallout from an eruption-related plume, regardless of size.

tonne (t): metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.

More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.

Additional Information:
For a definition of volcano alert levels and aviation color codes: http://volcanoes.usgs.gov/activity/alertsystem/index.php

Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.

A map with details of earthquakes located within the past two weeks can be found at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/

HVO Contact Information: askHVO@usgs.gov

The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.



Update Archive

Older updates can be found using the HVO Alert Archive Search.

New Update Format

For more information about the Volcano Alert Level and Aviation Color Code, please see the U.S. Geological Survey's Alert Notification System for Volcanic Activity Fact Sheet (pdf) or the USGS Volcanic Activity Alert-Notification System web page.