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Alaska Volcano Observatory

ALASKA VOLCANO OBSERVATORY CURRENT STATUS REPORTWednesday, February 8, 2012 12:34 PM (Wednesday, February 8, 2012 21:34 UTC)

CLEVELAND VOLCANO (CAVW #1101-24-)
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

There was no evidence of ash emissions or elevated surface temperatures in cloudy satellite images over the past day. There have been no indications of explosive ash-producing activity from satellite or from distant seismic, pressure or lightning sensors.

It remains possible for intermittent, sudden explosions of blocks and ash to occur at any time, and ash clouds exceeding 20,000 feet above sea level may develop. Such explosions and their associated ash clouds may go undetected in satellite imagery for hours. If a large, explosive, ash-producing event occurs, seismic, infrasound, or volcanic lightning may be detected by local and regional monitoring networks. There is no real-time seismic monitoring network on Mount Cleveland.

Additional information on Cleveland Volcano and the current activity may be found at this link:
http://www.avo.alaska.edu/activity/Cleveland.php

Please see http://www.avo.alaska.edu/color_codes.php for complete definitions of Aviation color codes and Volcano alert levels.

CONTACT INFORMATION:
John Power, Scientist-in-Charge, USGS
jpower@usgs.gov (907) 786-7497

Steve McNutt, Coordinating Scientist, UAF
steve@giseis.alaska.edu (907) 474-7131

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

CASCADES VOLCANO OBSERVATORY WEEKLY UPDATEFriday, February 3, 2012 10:42 AM PST (Friday, February 3, 2012 18:42 UTC)

CASCADE RANGE VOLCANOES
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Activity Update: All volcanoes in the Cascade Range are at normal levels of background seismicity. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State; Mount Hood, Mount Jefferson, Three Sisters, Newberry Volcano, and Crater Lake, in Oregon; and Medicine Lake volcano, Mount Shasta, and Lassen Peak in northern California.

Recent Observations: No unusual geologic activity was apparent at any of the Cascades Volcanoes during the week. Volcano seismicity remained at background levels. Hydrologic field teams collected stream data and serviced monitoring stations in Mount St. Helens drainages.

The U.S. Geological Survey and University of Washington continue to monitor these volcanoes closely and will issue additional updates and changes in alert level as warranted.

For other inquiries please call 360 993-8973.

For additional information, background, images, and other graphics: http://vulcan.wr.usgs.gov

For seismic information on Oregon and Washington volcanoes: http://old.pnsn.org/WEBICORDER/PNSN/welcome.html

For seismic information on California volcanoes: http://earthquakes.usgs.gov/eqcenter/recenteqsus/Maps/special/California_Nevada.php

For a definition of alert levels: http://vulcan.wr.usgs.gov/Volcanoes/Cascades/CurrentActivity/volcano_warning_scheme.html

For a webcam view of Mount St. Helens: http://www.fs.fed.us/gpnf/volcanocams/msh/

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATEWednesday, February 8, 2012 06:25 AM (Wednesday, February 8, 2012 16:25 UTC)

This report on the status of Kilauea volcanic activity, in addition to maps, photos, and Webcam images (available using the menu bar above), 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 for past 24 hours: Overall eruptive activity was low. DI inflation and the rising of the summit lava lake slowed last night. Within Pu`u `O`o Crater, glow was visible from sources on the northeast and southeast edges of the floor. Surface flows southeast of Pu`u `O`o resumed activity based on satellite imagery but there were no active surface flows on the pali, coastal plain, or entering the ocean. Seismic tremor levels were low and gas emissions were elevated.

Past 24 hours at Kilauea summit: The summit tilt network recorded slowing DI inflation and the lava lake rose at a slower rate. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on January 30, 2012; new measurements must await the return of moderate trade winds.

Seismic tremor levels remained low. One earthquake was strong enough to be located beneath Kilauea volcano on south flank faults.

Background: The summit lava lake is deep within a ~150 m (500 ft) diameter cylindrical vent with nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level fluctuates from about 70 m to more than 150 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. Most recently, the lava level of the lake has remained below an inner ledge (75 m or 250 ft below the floor of Halema`uma`u Crater) and responded to summit tilt changes with the lake receding during deflation and rising during inflation.

Past 24 hours at the middle east rift zone vents: The tiltmeter on the north flank of Pu`u `O`o cone recorded continued DI inflation. Within Pu`u `O`o crater, glow was visible from sources on the northeast and southeast edges of the crater floor and was strongest from the small cone on the northeast edge. Seismic tremor levels near Pu`u `O`o were low. The most recent (preliminary) sulfur dioxide emission rate measurement was 500 tonnes/day on January 29, 2012, from all east rift zone sources; new measurements must await the return of moderate trade winds.

On the flow field, satellite thermal anomaly intensities increased through yesterday and Webcams recorded glow above the pali suggesting that the surface flows 5 km (3 mi) southeast of Pu`u `O`o (above the pali) may have resumed activity. Farther southeast, Webcams recorded no surface flow activity on the pali or coastal plain and no active ocean entry.

Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and has continued since at Pu`u `O`o Cone, or from vents within a few kilometers to the east or west, with few interruptions. In early August, 2011, the Pu`u `O`o crater floor collapsed to a depth of about 75 m (245 ft) below the east rim of the crater as lava burst from vents on the lower west flank of the cone. A DI tilt event several days later cut off supply to Pu`u `O`o and the west flank vents; lava reappeared in Pu`u `O`o Crater on August 21st and filled it to overflowing. 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 that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawai`i Volcanoes National Park in early December. The ocean entry has been inactive since late December and the flows have been weakly active above the pali since mid-January. 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 and adjacent State land managed by the Department of Land and Natural Resources; they do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. 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 - There are minor active lava flows within the closed-access Kahauale'a Natural Area Reserve (NAR), which can only be viewed from the air. Glow from flows can sometimes be seen under favorable weather conditions from the County Viewing Area at Kalapana. Pu`u `O`o Cone, the (inactive) West Ka`ili`ili lava ocean entry, and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

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://tux.wr.usgs.gov/

A definition of alert levels can be found at http://volcanoes.usgs.gov/activity/alertsystem/index.php

Definitions of Terms Used:

fill-and-drain cycles: one of the cyclical behaviors exhibited by the summit lava lake. A fill-and-drain cycle starts with a rise in lava level, a decrease in summit tremor amplitude, and a small decrease in tilt. After a period of minutes to hours, the lava will abruptly drain back to its previous level, seismic tremor amplitude will increase, and summit tilt will return to its previous level. Although not measured continuously, spot checks of gas emissions demonstrate that far less gas is released during the high lava stand than during its draining phase suggesting that, during the high lava stand, lava is puffed up with gas trapped by crusts on the lava surface.

perched lava lake: a lava lake within a rim that is progressively built up by overflows of lava that have cooled and solidified. The most recent example of a perched lava lake is currently active within Pu`u `O`o maintaining a rim standing several meters (yards) above the crater floor. In many ways, a perched lava lake resembles an above-ground swimming pool. Overflows from the pond add layers to the surrounding crater floor building it higher; the overflows also build up the perched lake rim, continually keeping the lake rim raised above the floor.

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).

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 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 140 m (460 ft) in diameter at the Halema`uma`u Crater floor, is about 50 m in diameter at the pit floor, and is about 200 m (660 ft) deep. As of November, 2009, a lava pond surface has been visible in a hole in the floor of 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.

DI tilt event: DI is an abbreviation for 'deflation-inflation' and describes a volcanic event of uncertain 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 to 2-3 days 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/July 21/TEB vents.

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.

LONG VALLEY OBSERVATORY WEEKLY UPDATEThursday, January 12, 2012 5:46 PM PST (Friday, January 13, 2012 01:46 UTC)

LONG VALLEY VOLCANIC CENTER VOLCANO (CAVW #1203-14-)
37°42' N 118°52'12" W, Summit Elevation 7231 ft (2204 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Fifteen earthquakes with magnitudes between M=1.0 and M=1.8 occurred in the Mammoth Lakes-Long Valley region in the last seven days. The events were located in the Sierra Nevada, with the exception of three earthquakes in the caldera east of the town of Mammoth Lakes and one event in Round Valley.

NORTHERN MARIANA ISLANDS WEEKLY UPDATEFriday, February 3, 2012 01:54 PM (Friday, February 3, 2012 03:54 UTC)

Report prepared by the U.S. Geological Survey.

PAGAN VOLCANO (CAVW #0804-17=)
18°7'48" N 145°48' E, Summit Elevation 1870 ft (570 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Low-level volcanic unrest continues at Pagan. On 30 January the USGS received a pilot report via the National Weather Service office in Guam of a volcanic cloud rising to an altitude of 10,000 ft asl. The cloud was described as 'white with bits of light brown'. Satellite images of Pagan from the time of the PIREP showed a vigorous gas and steam cloud but no evidence of a significant amount of volcanic ash. Other satellite images over the past week showed a gas and steam plume drifting downwind from the volcano. The USGS received no further reports of unrest or activity at Pagan volcano.

Pagan Volcano is not monitored with ground-based geophysical instrumentation and the only sources of information are satellite observations and occasional reports from observers who pass by or visit the island. We will continue to evaluate satellite imagery, on-island, and mariner reports when they become available, but because the volcano is not monitored with ground-based instruments, we cannot provide advanced warning of activity.

Access to the island may be restricted by the CNMI government. Contact the EMO for the latest information.

No eruptive activity or significant unrest has been detected at other volcanoes in Northern Mariana Islands this week.

CONTACT INFORMATION:
USGS Northern Marianas Duty Scientist (808) 967-8815
http://volcano.wr.usgs.gov/cnmistatus.php

CNMI Emergency Management Office (670) 322-8001
http://www.cnmiemo.gov.mp/

YELLOWSTONE VOLCANO OBSERVATORY MONTHLY UPDATEWednesday, February 1, 2012 12:59 PM MST (Wednesday, February 1, 2012 19:59 UTC)

YELLOWSTONE VOLCANO (CAVW #1205-01-)
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

During January 2012, 26 earthquakes were located in the Yellowstone National Park region. The largest was a magnitude 2.5 event on January 18 at 2:32 AM MST, located about 7 miles north northeast of West Yellowstone, MT.

Yellowstone earthquake activity continues at relatively low background levels and no swarms were detected.

Slow subsidence of the caldera, which began in early 2010, continues. Current deformation patterns at Yellowstone are well within historical norms.

Please see: http://www.uusatrg.utah.edu/ts_ysrp.html for a map of GPS stations in the Yellowstone vicinity. For a graph of daily GPS positions at White Lake, within the Yellowstone caldera, please see: http://pboweb.unavco.org/shared/scripts/stations/?checkkey=WLWY&sec=timeseries_plots

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The Yellowstone Volcano Observatory (YVO) is a partnership of the U.S. Geological Survey (USGS), Yellowstone National Park, and University of Utah to strengthen the long-term monitoring of volcanic and earthquake unrest in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

CONTACT INFORMATION:
Jacob Lowenstern, USGS
Scientist-in-Charge, Yellowstone Volcano Observatory
jlwnstrn@usgs.gov

Robert Smith, University of Utah
Coordinating Scientist, YVO

Henry Heasler, Yellowstone National Park
Coordinating Scientist, YVO