Recent Kilauea Status Reports, Updates, and Information Releases
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Saturday, October 5, 2013 7:00 AM HST (Saturday, October 5, 2013 17:00 UTC)
The U.S. Volcano Observatories will remain operational during the lapse of federal government appropriations. Basic volcano monitoring will continue, as will forecasts and regular updates of volcanic activity. However, because of reduced staff, instrument network maintenance will cease, meaning that our monitoring capability will degrade over time. Our websites will remain functional, but only those pages containing information about current volcano hazards will be maintained.
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 (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded inflation while the lava lake rose slowly. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o may host small breakouts above the top of the pali. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded inflation after midnight last night increasing in rate during early morning hours; the current inflation rate is very similar to the initial rate of DI inflation overnight on Oct. 2-3 as if DI inflation is resuming after being interrupted for 48 hours. The lava lake dropped several meters during the morning yesterday, stabilized through the afternoon and overnight, and started to rise after 2 am this morning. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated and remained low with no dropouts. Twenty-five earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 1 beneath the lower southwest rift zone, 4 in the Ka`oiki Pali area, 1 beneath Halema`uma`u Crater, 5 beneath the north rim of the summit caldera, 8 south of Halema`uma`u Crater (flurry around midday yesterday), 3 within the upper east rift zone, and 3 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events).
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded fluctuations with an increase early this morning that is suspiciously coincident with rainfall in the area. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations over weak extension. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor displayed persistent glow while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of a satellite image on 09/30). PNcam views showed scattered active breakouts at the northern extremities of the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line in two locations north of Pu`u `O`o.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; MODIS imagery of this flow was obscured by clouds over the past 24 hours but the Kalapana Viewing Area crew reported glow most likely from these minor Peace Day flow breakouts.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. Hawai`i Volcanoes National Park is closed as of October 1, 2013, due to a lapse in appropriations.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Friday, October 4, 2013 7:48 AM HST (Friday, October 4, 2013 17:48 UTC)
The U.S. Volcano Observatories will remain operational during the lapse of federal government appropriations. Basic volcano monitoring will continue, as will forecasts and regular updates of volcanic activity. However, because of reduced staff, instrument network maintenance will cease, meaning that our monitoring capability will degrade over time. Our websites will remain functional, but only those pages containing information about current volcano hazards will be maintained.
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 (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded stable conditions while the lava lake rose slowly. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o may host small breakouts above the top of the pali. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded the apparent end of DI inflationary tilt at 7 am yesterday morning followed by featureless tilt - neither inflationary nor deflationary trend. The lava lake dropped several meters at about 3am yesterday and, for the next 7 hours, multiple spattering sinks moved around its edges and its circulation patterns and level changed frequently; at about 10 am, the lake rose and settled, resumed its normal north-south circulation pattern and for the rest of the day and last night, its level rose slowly. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels remained low after doubling between 3 and 10:30 am yesterday; the period of high tremor was roughly coincident with the drop and disruption of the lava lake noted above. Eight earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 4 within the southwest rift zone, 1 beneath Halema`uma`u Crater, and 3 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th and about 1.5 cm of extension between Sept. 21 to 30 culminating in the small seismic flurry within the upper east rift zone midday Sunday; the cross-caldera GPS receiver pair recorded contraction mimicking the short-term DI tilt event over the past 2-3 days.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded fluctuations over weak deflationary tilt. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations over extension from Sept. 26 to 29 that resumed yesterday. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor displayed persistent glow while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of a satellite image on 09/30). PNcam views showed scattered active breakouts at the northern extremities of the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line north of Pu`u `O`o.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; early yesterday afternoon, a MODIS image showed a single thermal anomaly suggesting that one of these minor breakouts continued to be active; other satellite images were obscured by clouds.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. Hawai`i Volcanoes National Park is closed as of October 1, 2013, due to a lapse in appropriations.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.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
Thursday, October 3, 2013 7:54 AM HST (Thursday, October 3, 2013 17:54 UTC)
The U.S. Volcano Observatories will remain operational during the lapse of federal government appropriations. Basic volcano monitoring will continue, as will forecasts and regular updates of volcanic activity. However, because of reduced staff, instrument network maintenance will cease, meaning that our monitoring capability will degrade over time. Our websites will remain functional, but only those pages containing information about current volcano hazards will be maintained.
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 (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded the switch to DI inflationary tilt late last night while the lava lake initially rose with the switch but then became agitated for a few hours. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o may host small breakouts above the top of the pali. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded the switch to DI inflationary tilt at 10 pm last night. The lava lake initially rose with the switch in tilt but became very agitated around 3 am this morning, possibly initiated by a very small rockfall; the lake settled into its normal circulation pattern by the time of this posting. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated but remained low with 5 dropouts between 11 pm on Oct. 1 and 3 am on Oct. 3 (this morning). Sixteen earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 1 beneath the southwest rift zone, 2 south of the summit caldera, 4 beneath the summit caldera, 2 within the upper east rift zone, and 7 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th and about 1.5 cm of extension between Sept. 21 to 30 culminating in the small seismic flurry within the upper east rift zone midday Sunday; the cross-caldera GPS receiver pair recorded contraction mimicking the short-term DI tilt event over the past 2-3 days.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded fluctuations over weak deflationary tilt. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations over extension from Sept. 26 to 29 that resumed yesterday. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor displayed persistent glow while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of a satellite image on 09/30). PNcam views showed scattered active breakouts along the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line north of Pu`u `O`o; flow vigor, as shown by the number of active breakouts overnight, seems to be low.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; yesterday, most MODIS imagery was obscured by clouds and rain "washed out" visibility from the Kalapana Viewing Area so continued activity of these breakouts cannot be confirmed.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. Hawai`i Volcanoes National Park is closed as of October 1, 2013, due to a lapse in appropriations.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Wednesday, October 2, 2013 7:00 AM HST (Wednesday, October 2, 2013 17:00 UTC)
The U.S. Volcano Observatories will remain operational during the lapse of federal government appropriations. Basic volcano monitoring will continue, as will forecasts and regular updates of volcanic activity. However, because of reduced staff, instrument network maintenance will cease, meaning that our monitoring capability will degrade over time. Our websites will remain functional, but only those pages containing information about current volcano hazards will be maintained.
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 (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded slowing DI deflationary tilt while the lava lake level dropped several meters (yards). At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o may host small breakouts above the top of the pali. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded slowing deflationary tilt and the lava lake level continued to drop, reaching a level of about 54-55 m (177-180 ft) below the Halema`uma`u Crater floor. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated but remained low with dropouts overnight. Twenty-three earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 5 beneath Halema`uma`u Crater, 7 south and west of the summit caldera, 6 within the upper east rift zone (near Ko`oko`olau Crater), and 5 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th and about 1.5 cm of extension between Sept. 21 to 30; this brief period of extension culminated in the small seismic flurry within the upper east rift zone midday Sunday.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded about 0.5 microradians of deflationary tilt yesterday morning followed by neither deflation or inflation. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations over extension from Sept. 26 to 29. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor showed diminished glow while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of 9/19). PNcam views showed scattered active breakouts along the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line north of Pu`u `O`o; flow vigor, as shown by the number of active breakouts overnight, seems to be low.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; yesterday, most MODIS imagery was obscured by clouds with one scene that showed a very weak thermal anomaly in the Peace Day upper flow field.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. Hawai`i Volcanoes National Park is closed as of October 1, 2013, due to a lapse in appropriations.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.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
Tuesday, October 1, 2013 7:47 AM HST (Tuesday, October 1, 2013 17:47 UTC)
The U.S. Volcano Observatories will remain operational during the lapse of federal government appropriations. Basic volcano monitoring will continue, as will forecasts and regular updates of volcanic activity. However, because of reduced staff, instrument network maintenance will cease, meaning that our monitoring capability will degrade over time. Our websites will remain functional, but only those pages containing information about current volcano hazards will be maintained.
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 (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded the start of a DI deflationary tilt while the lava lake level receded slightly. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o may host small breakouts above the top of the pali. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded what appears to be the start of strong DI deflationary tilt at about 4 am this morning. The lava lake level dropped slightly through yesterday and remained at a depth estimated to be about 48-49 m (157-161 ft) below the Halema`uma`u Crater floor. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, all of these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated but remained low with a single dropout starting at 4:30 am this morning. Thirty-seven earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 6 within the southwest rift zone, 25 within the upper east rift zone (small flurry yesterday morning), 1 north of the middle east rift zone, and 5 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded the start of a DI deflationary tilt at about 5 am - an hour after it started at the summit. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations over extension since Sept. 21. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor showed continued incandescence while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of 9/19). PNcam views showed scattered active breakouts along the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line north of Pu`u `O`o; flow vigor, as shown by the number of active breakouts overnight, seems to be decreasing slowly.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; MODIS imagery was obscured by clouds and there was no report yet from the Kalapana Viewing Area crew.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 0.984 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.php.
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawai`i.
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Monday, September 30, 2013 7:47 AM HST (Monday, September 30, 2013 17:47 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). Hawai`i Volcanoes National Park status can be found at http://www.nps.gov/havo/ or 985-6000. All times are Hawai`i Standard Time.
KILAUEA VOLCANO (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded neither inflationary nor deflationary tilt after a week of inflationary tilt while the lava lake level receded slightly. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o hosted at least one breakout at the top of the pali which is reported visible from Kalapana. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded relatively flat tilt ending a week of weak inflationary tilt (about +0.4 microradians/day since Sept. 22). The lava lake level fell a bit and, this morning, stands about 47-48 m (154-157 ft) below the Halema`uma`u Crater floor. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, all of these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. A small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated but remained low with a single 4-hr dropout overnight. Twenty earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 2 in the Ka`oiki Pali area, 7 clustered south of Halema`uma`u Crater, 5 within the upper east rift zone, and 6 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded minor fluctuations with increases that are suspiciously similar to cumulative rainfall in the area. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations with no longer-term trend. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor showed continued incandescence while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of 9/19). PNcam views showed scattered active breakouts along the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line north of Pu`u `O`o; flow vigor, as shown by the number of active breakouts overnight, seems to be decreasing slowly.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; a MODIS image late yesterday evening including an indistinct thermal anomaly southeast of Pu`u `O`o at about the location of the lower breakout. This thermal anomaly and reports by the Kalapana Viewing Area crew since 9/24 that lava is visible at the top of the pali are consistent with continued activity of the lowest breakout.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 1.1 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.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
Sunday, September 29, 2013 7:25 AM HST (Sunday, September 29, 2013 17:25 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). Hawai`i Volcanoes National Park status can be found at http://www.nps.gov/havo/ or 985-6000. All times are Hawai`i Standard Time.
KILAUEA VOLCANO (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded continuing weak inflationary tilt while the lava lake level continued to rise about 2-3 m (7-10 ft) per day. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning two patches of forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o hosted at least one breakout at the top of the pali which is reported visible from Kalapana. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded continuing weak inflationary tilt (about +0.4 microradians/day) since Sept. 22. The lava lake level continued to rise and, this morning, stands about 43-44 m (141-144 ft) below the Halema`uma`u Crater floor. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, all of these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated but remained low with no dropouts. Nine earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 1 south of Halema`uma`u Crater, 4 within the upper east rift zone, and 4 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded minor fluctuations with increases that are suspiciously similar to rainfall in the area. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations with no longer-term trend. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor showed continued incandescence while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of 9/19); the bright glow at the top of the highest spatter cone in this complex dimmed twice - at about 9:40 am yesterday and 3 am this morning - and a small flow lava followed the first dimming. PNcam views showed scattered active breakouts along the tube-fed Kahauale`a 2 pahoehoe flow edges and continued burning along the forest line north of Pu`u `O`o.
On the Peace Day flow, HVO geologists on the most recent overflight (Thursday, 9/19) found two small breakouts 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; a MODIS image late yesterday evening including a distinct thermal anomaly southeast of Pu`u `O`o at about the location of the lower breakout. This thermal anomaly and reports by the Kalapana Viewing Area crew since 9/24 that lava is visible at the top of the pali are consistent with continued activity of the lowest breakout.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 1.1 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.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
Saturday, September 28, 2013 6:53 AM HST (Saturday, September 28, 2013 16:53 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). Hawai`i Volcanoes National Park status can be found at http://www.nps.gov/havo/ or 985-6000. All times are Hawai`i Standard Time.
KILAUEA VOLCANO (CAVW #1302-01-) 19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m) Current Volcano Alert Level: WATCH Current Aviation Color Code: ORANGE
Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded continuing weak inflationary tilt while the lava lake level rose slightly. At the middle east rift zone, the Kahauale`a 2 lava flow was active as multiple breakouts still burning two patches of forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o was much less active than in the past and may only host minor breakouts in its upper flow field. Gas emissions remained elevated.
Recent Observations at Kilauea summit: Summit tiltmeters recorded continuing weak inflationary tilt (about +0.4 microradians/day) since Sept. 22. The lava lake level continued to rise and, this morning, stands about 46-47 m (151-154 ft) below the Halema`uma`u Crater floor. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on September 27, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, all of these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was probably carried out of the vent with the gas and deposited onto nearby surfaces.
Seismic tremor levels fluctuated but remained low with one dropout between 8 pm last night and 1 am this morning. Fourteen earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 3 in the Ka`oiki Pali area west of the summit, 4 within the upper east rift zone, and 7 on south flank faults. GPS receivers spanning the summit caldera respond to the short-term changes in tilt (DI tilt events) over a trend of slow contraction since August 26th.
Background: The summit lava lake is within a cylindrical vent cavity with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded minor fluctuations. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on September 23, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone show minor fluctuations with no longer-term trend. The Pu`u `O`o vent fed two lava flow fields - most of the lava appeared to be feeding the Kahauale`a 2 flow to the north while activity on the older Peace Day flow to the southeast was only present in two small patches above the pali.
Spatter cones on the north and south portion of the Pu`u `O`o crater floor showed continued incandescence while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 3.6 km (2.2 mi) to the north (as of 9/19). PNcam views showed scattered active breakouts along the Kahauale`a 2 flow edges and continued burning along the forest line north of Pu`u `O`o.
HVO geologists on an overflight Thursday (9/19) found two small breakouts on the Peace Day flow 2.7 km (1.7 mi) and 6 km (3.7 mi) southeast of Pu`u `O`o above the pali; MODIS images over the past 24 hours cannot confirm any thermal anomalies southeast of Pu`u `O`o; however, this may be due to blockage by clouds covering the area of interest.
Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o 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 Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary:East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided. Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.
Viewing Summary:East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.
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
Definitions of Terms Used:
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.
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.
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).
pali: Hawaiian term for cliff or precipice.
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.
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.
glow: light from an unseen source; indirect light.
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).
CD: Hawai`i County Civil Defense
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 1.1 English tons.
tephra: all material deposited by fallout from an eruption-related plume, regardless of size.
ash: tephra less than 2 mm (5/64 inches) in size.
microradian: a measure of angle equivalent to 0.000057 degrees.
More definitions with photos can be found at http://volcanoes.usgs.gov/images/pglossary/index.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.
