HVO Kilauea Status

Recent Kilauea Status Reports, Updates, and Information Releases

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Friday, December 19, 2014 9:13 AM HST (Friday, December 19, 2014 19:13 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 Volcano continues to erupt at its summit and within its East Rift Zone. A lava flow front consisting of north and south branches remains generally active, although the southern branch appears to have stalled as of this morning. The flow front has advanced ~120 m (~130 yds) since yesterday morning according to Civil Defense. The leading edge of this front is approximately 1.3 km (0.8 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. The summit deflation event that began Wednesday evening turned around Thursday morning. No significant tilt has been observed at Puʻu ʻŌʻō since yesterday's report.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a flow front that branches off the west edge of the flow field below the crack system. Civil Defense reported this morning that the leading edge of the active flow was about 1.3 km (0.8 miles) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. HVO observers reported this morning that the southern branch of the flow had stalled but the north branch remains active. The descent path of the active north branch, if it continues to be followed, would take it to the Pāhoa Marketplace. In addition to this active flow front, breakouts from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remain active. Several other breakouts, scattered along the edges and interior of the flowfield from 2 to 3.7 km (1.2 to 2.3 miles) with advancements of up to about 200 meters (220 yards) were also mapped by HVO personnel during yesterday's overflight.

Puʻu ʻŌʻō Observations: No significant change in ground tilt has been observed in the past 24 hours, and overall for the last week ground tilt measured at the cone has been minor and deflationary. Two hot openings were observed in each of northeast and south pits within the crater during yesterday's HVO overflight. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 300 tonnes per day on December 11, 2014.

Summit Observations: A tiltmeter at Kīlauea's summit recorded the turnaround of the summit deflation that began Wednesday night; inflation restarted at about 10:00 yesterday morning and has regained about half the tilt that was lost in the DI event. The summit lava lake has shown the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes and gas release. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide ranged between 3,100 and 6,500 tonnes/day for the week ending on December 16 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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 CURRENT STATUS REPORT
U.S. Geological Survey
Thursday, December 18, 2014 10:00 PM HST (Friday, December 19, 2014 08:00 UTC)


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

USGS Hawaiian Volcano Observatory (HVO) scientists conducted an overflight of the June 27th lava flow and Puʻu ʻŌʻō this early afternoon. The active lava lobe advanced about 340 m (370 yd) since December 16; the flow front split into two branches, one following the steepest descent path in the area and another following a “tributary” path to the north that intersects the main descent path a few hundred meters (yards) downslope. The flow tip was 1 km (0.6 mi) from the Pāhoa Marketplace. Several breakouts were also scattered along the edges and interior of the flow 2 to 3.7 km (1.2 to 2.3 mi) upslope of the flow front, similar to activity of the past several days.

The eruption rate measured today from the Pu`u` Ō`ō vent is similar to measurements made on December 9 and 16. Several breakouts from the tube were still occurring in the upper flow field, about 3.2 km (2 mi) from Pu`u` Ō`ō and in the crack system 8.5 km (5.3 mi) farther downslope, but they appeared to be less active compared to observations earlier this week.

Daily updates about Kilauea's ongoing eruptions, recent images and videos of summit and East Rift Zone volcanic activity, and data about recent earthquakes are posted on the HVO Web site at http://hvo.wr.usgs.gov.

Additional Information:

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.

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

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
U.S. Geological Survey
Thursday, December 18, 2014 9:21 AM HST (Thursday, December 18, 2014 19:21 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 Volcano continues to erupt at its summit and within its East Rift Zone. A lava flow front consisting of two fingers remains active and advanced ~150 m (~165 yds) since yesterday according to Civil Defense. The leading edge of this front is approximately 1.3 km (0.8 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. A summit deflation event began last evening. No significant tilt has been observed at Puʻu ʻŌʻō since yesterday's report.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a flow front that branches off the west edge of the flow field below the crack system. Civil Defense reported this morning that the leading edge of the flow was about 1.3 km (0.8 miles) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. As of this morning, Civil Defense photos also show that the flow front consists of two closely spaced fingers, both headed towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. In addition to this active flow front, breakouts from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remain active. Yesterday, HVO staff installed two new time lapse web cameras in the vicinity of Pāhoa Marketplace. One of these cameras is trained on the market itself, and the other is directed up slope. Images from these cameras are available on the HVO website under the heading Webcams/ East Rift Zone.

Puʻu ʻŌʻō Observations: No significant change in ground tilt has been observed in the past 24 hours. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 300 tonnes per day on December 11, 2014.

Summit Observations: A tiltmeter at Kīlauea's summit recorded the onset of summit deflation beginning at about 7:00 pm last night. The last such event occurred on 14 December and lasted about a day. The summit lava lake has shown the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes and gas release. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide ranged between 3,100 and 6,500 tonnes/day for the week ending on December 16 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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
U.S. Geological Survey
Wednesday, December 17, 2014 9:02 AM HST (Wednesday, December 17, 2014 19:02 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 Volcano continues to erupt at its summit and within its East Rift Zone. A lobe of lava remains active and advanced ~200 m (~220 yds) since yesterday according to Civil Defense. The leading edge of this lobe is approximately 1.4 km (0.9 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. No significant tilt has been observed at Kīlauea's summit or at Puʻu ʻŌʻō since yesterday's report.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a flow lobe that branches off the west edge of the flow field below the crack system. Civil Defense reported, this morning, that the leading edge of the flow was about 1.4 km (0.9 miles) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. Yesterday, HVO scientists on-site observed that the active lobe had widened somewhat, and had turned slightly to the north at a point where the steepest-descent path turns sharply east. This path, however, would rejoin a steepest descent tributary that would still direct the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. In addition to this active lobe, a breakout from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remains weakly active.

Puʻu ʻŌʻō Observations: Tilt trend at Puʻu ʻŌʻō shows no significant change during the last day. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 310 tonnes per day on December 11, 2014.

Summit Observations: No significant change in ground tilt has been observed in the past 24 hours. The summit lava lake showed the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide was 4,100 tonnes/day for the week ending on December 9 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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: Tuesday, December 16, 2014, 10:06 PM HST (20141217/0806Z)
Source: Hawaiian Volcano Observatory
Notice Number: 2014/H21
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 a new lobe advancing an average of 285 m/day (310 yd/day) between December 9 and 16; the leading edge is about 1.5 km (0.9 mi) from the Pahoa Marketplace, located near the intersection of Highway 130 and Pāhoa Village Road. Since this new flow broke out from the lava tube along a crack system on about November 19, its advance rate has varied from less than 100 m/day (110 yd/day) to more than 450 m/day (490 yd/day), averaging nearly 300 m/day (330 yd/day).

From the breakout point in the crack system the flow is now about 8 km (5 m) in length, and has moved along a new calculated steepest descent path based on a 1983 digital elevation model of the ground. The steepest descent path leads to the Pahoa Marketplace. At the average rate of advance of the past week, lava could reach the marketplace and Highway 130 in about 5 days, warranting this Volcanic Activity Notice.

The eruption rate measured today from the Pu`u` Ō`ō vent is not significantly different from the measurement obtained on December 9. A tiltmeter at Kīlauea’s summit recorded an overall inflationary trend during the past week, but has not changed in the past 24 hours. This suggests that the advance rate of the active flow is not likely to slow appreciably during the next few days, barring a sudden, significant deflationary tilt at the summit or large, new breakouts upslope.

Several breakouts upslope were observed by HVO scientists during today’s overflight along the margins of the new flow and also from the crack system and upslope near Pu`u` Ō`ō. These breakouts, however, have not slowed the active flow front based on today’s observations.

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


Recent Observations:
[Lava flow] A new lobe of the June 27th lava flow has advanced toward the Pahoa Marketplace at about 285 m/day (310 yd/day) since December 9. The leading edge is now about 1.5 km (0.9 mi) as measured along the steepest descent path to the marketplace.
[Volcanic cloud height] Unknown
[Other volcanic cloud information] Unknown

Hazard Analysis:
[Lava flow] A new lobe of the June 27th lava flow from the Pu`u` Ō`ō vent is active, steadily advancing downslope toward Highway 130 and the Pahoa Marketplace. At an average advance rate of 285 m/day (310 yd/day), the flow front could reach the marketplace within 5 days.

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 (1,300 ft/day). This flow advanced downslope fitfully before stalling in Pāhoa on October 30 about 155 m (170 yd) from Pāhoa Village Road. Breakouts upslope continued to widen the flow, however, through mid-November.

A large breakout near Pu`u `Ō`ō November 14-15 temporarily diverted lava from the tube onto the surface, thereby shutting off lava supply to the lower flow. Within a few days, several breakouts along the tube indicated lava had reoccupied the tube as far as about 12 km (7.5 mi) from Pu`u `Ō`ō. The lowermost breakout in the crack system became the source for the new active lobe. This lobe also moved north-northeast on top of and along the west margin of the earlier inactive flow, eventually moving into forest and following a new steepest descent path that leads to the Pahoa Marketplace.

Contacts: HVO media contact
askHVO@usgs.gov

Next Notice: Daily updates on all volcanic activity at Kīlauea, including the June 27th flow, will be issued each morning, and status reports will be made as new information becomes available. 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
U.S. Geological Survey
Tuesday, December 16, 2014 9:00 AM HST (Tuesday, December 16, 2014 19:00 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 Volcano continues to erupt at its summit and within its East Rift Zone. A narrow lobe of lava north and west of the flow field below the crack system remains active and advanced ~250 m (~275 yds) since yesterday. The leading edge of this lobe is approximately 1.6 km (1.0 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. At Kīlauea's summit after a slight decrease in tilt, inflationary tilt has begun as of 4 AM last night.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a narrow flow lobe that branches off the west edge of the flow field below the crack system. Civil Defense reported, this morning, that the leading edge of the flow was about 1.6 km (1.0 miles) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. The active lobe is following a steepest-descent path that takes the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. In addition to this active lobe, a breakout from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remains weakly active.

Puʻu ʻŌʻō Observations: Tilt trend at Puʻu ʻŌʻō shows a slight decrease in tilt. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 250 tonnes per day on November 26, 2014.

Summit Observations: After slight decrease in tilt, inflationary tilt has begun as of 4 AM last night. The summit lava lake showed the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide was 4,100 tonnes/day for the week ending on December 9 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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
U.S. Geological Survey
Monday, December 15, 2014 8:59 AM HST (Monday, December 15, 2014 18:59 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 Volcano continues to erupt at its summit and within its East Rift Zone. A narrow lobe of lava west of the flow field below the crack system remains active. The leading edge of this lobe, as reported by Civil Defense yesterday, was approximately 2.25 km (1.4 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. At Kīlauea's summit after a slight decrease in tilt, inflationary tilt has begun as of 1 AM last night.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a narrow flow lobe that branches off the west edge of the flow field below the crack system. At the time of this morning's report there was no Civil Defense over flight but, based on our webcam images the flow continues to remain active and advance toward the region of the Pāhoa Marketplace. The active lobe is following a steepest-descent path that takes the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. In addition to this active lobe, a breakout from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remains weakly active.

Puʻu ʻŌʻō Observations: Tilt trend at Puʻu ʻŌʻō has returned to pre-rain levels and there is no marked change. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 250 tonnes per day on November 26, 2014.

Summit Observations: At Kīlauea's summit after a slight decrease in tilt, inflationary tilt has begun as of 1 AM last night. The summit lava lake showed the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide was 4,100 tonnes/day for the week ending on December 9 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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
U.S. Geological Survey
Sunday, December 14, 2014 8:55 AM HST (Sunday, December 14, 2014 18:55 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 Volcano continues to erupt at its summit and within its East Rift Zone. A narrow lobe of lava west of the flow field below the crack system remains active and advanced ~275 m (~300 yds) since yesterday. The leading edge of this lobe is approximately 2.25 km (1.4 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. After a slight increase in tilt, Kīlauea's summit began a deflationary tilt trend starting at 2 AM last night.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a narrow flow lobe that branches off the west edge of the flow field below the crack system. Civil Defense reported, this morning, that the leading edge of the flow was about 2.25 km (1.4 mi) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. The active lobe is following a steepest-descent path that takes the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. In addition to this active lobe, a breakout from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remains weakly active. The breakout is about 1 km (0.6 mi) long, and has widened the flow field in this area by about 200 m (220 yd).

Puʻu ʻŌʻō Observations: Tilt trend at Puʻu ʻŌʻō is essentially flat or no marked change. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 250 tonnes per day on November 26, 2014.

Summit Observations: After a slight increase in tilt, deflationary tilt has begun as of 2 AM last night. The summit lava lake showed the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide was 4,100 tonnes/day for the week ending on December 9 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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
U.S. Geological Survey
Saturday, December 13, 2014 9:04 AM HST (Saturday, December 13, 2014 19:04 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 Volcano continues to erupt at its summit and within its East Rift Zone. A narrow lobe of lava west of the flow field below the crack system remains active and advanced ~205 m (~225 yds) since yesterday. The leading edge of this lobe is approximately 2.7 km (1.7 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. Inflationary tilt continues today at Kīlauea's summit.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a narrow flow lobe that branches off the west edge of the flow field below the crack system. Civil Defense reported, this morning, that the leading edge of the flow was about 2.7 km (1.7 mi) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. The active lobe is following a steepest-descent path that takes the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. The flow front has also entered a burn scar which has significantly reduced the amount of smoke seen from the flow front in our webcams. In addition to this active lobe, a breakout from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remains weakly active. The breakout is about 1 km (0.6 mi) long, and has widened the flow field in this area by about 200 m (220 yd).

Puʻu ʻŌʻō Observations: Tilt trend at Puʻu ʻŌʻō has an inflationary trend but, we attribute that to the recent rain that occurred in the past few days. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 250 tonnes per day on November 26, 2014.

Summit Observations: The inflationary ground tilt at the summit continues today. The summit lava lake showed the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide was 4,100 tonnes/day for the week ending on December 9 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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 CURRENT STATUS REPORT
U.S. Geological Survey
Friday, December 12, 2014 7:35 PM HST (Saturday, December 13, 2014 05:35 UTC)


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

USGS Hawaiian Volcano Observatory (HVO) scientists conducted field mapping around the leading tip of active lava on the June 27th lava flow. The active lobe has advanced about 900 meters (0.6 miles) since the afternoon of December 9, which is equivalent to an average advance rate of approximately 320 meters per day (0.2 miles per day).

The leading edge of this lobe was 2.7 km (1.7 miles) upslope from the intersection of Highway 130 and Pāhoa Village Road at the Pahoa Marketplace, as measured along a straight line. The active lobe is following a steepest-descent path that takes the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pahoa Marketplace. The leading edge of the lobe was 2.6 km (1.6 miles) upslope from the edge of Pahoa Marketplace, as measured along this path of steepest-descent.


Daily updates about Kilauea's ongoing eruptions, recent images and videos of summit and East Rift Zone volcanic activity, and data about recent earthquakes are posted on the HVO Web site at http://hvo.wr.usgs.gov.

Additional Information:

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.

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

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
U.S. Geological Survey
Friday, December 12, 2014 9:03 AM HST (Friday, December 12, 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 Volcano continues to erupt at its summit and within its East Rift Zone. A narrow lobe of lava west of the flow field below the crack system remains active and advanced ~320 m (~350 yds) since yesterday. The leading edge of this lobe is approximately 2.8 km (1.8 miles) above the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. Inflationary tilt continues today at Kīlauea's summit.

June 27th Lava Flow Observations: HVO, along with Civil Defense, is monitoring a narrow flow lobe that branches off the west edge of the flow field below the crack system. Civil Defense reported, this morning, that the leading edge of the flow was about 2.9 km (1.8 mi) upslope from the intersection of Pāhoa Village Road and Highway 130, near the Pāhoa Marketplace. The active lobe is following a steepest-descent path that takes the flow towards the intersection of Pāhoa Village Road and Highway 130, in the vicinity of the Pāhoa Marketplace. The flow front has also entered a burn scar which has significantly reduced the amount of smoke seen from the flow front in our webcams. In addition to this active lobe, a breakout from the lava tube on December 5, about 2.6 km (1.6 mi) from Puʻu ʻŌʻō remains weakly active. The breakout is about 1 km (0.6 mi) long, and has widened the flow field in this area by about 200 m (220 yd).

Puʻu ʻŌʻō Observations: Tilt trend at Puʻu ʻŌʻō has leveled off for now. All other monitoring data indicate no significant changes at Puʻu ʻŌʻō. Seismic tremor is low and steady, and webcams revealed no strong variations in the pattern of glow from degassing vents or the configuration of the crater floor. GPS-measured deformation across the cone has shown no net extension nor contraction since July. The most recent measurement of sulfur dioxide emissions from the East Rift Zone was about 250 tonnes per day on November 26, 2014.

Summit Observations: The inflationary ground tilt at the summit continues today. The summit lava lake showed the usual fluctuations associated with changes in spattering behavior, which are also manifested as variations in tremor amplitudes. Small amounts of particulate material were carried aloft by the plume. The average emission rate of sulfur dioxide was 4,100 tonnes/day for the week ending on December 9 (see caveat below).



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 have advanced into Pāhoa and may threaten residential areas depending on their level of activity and advance rate. 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.