Current Alerts for U.S. Volcanoes
- 2010-02-09 10:13:28 Kilauea Watch Orange
- 2010-02-08 16:57:53 Yellowstone Normal Green
- 2010-02-05 12:49:22 Long Valley Volcanic Center Normal Green
- 2010-02-05 09:31:05 Cascade Range Normal Green
- 2010-02-01 17:04:42 Mauna Loa Advisory Yellow
- 2010-01-14 15:16:34 Anatahan Normal Green
- 2010-01-05 15:32:58 Redoubt Normal Green
Subscribe to our feed
Alaska Volcano Observatory
AVO/USGS Volcanic Activity NoticeVolcano: Redoubt (CAVW #1103-03-)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Issued: Tuesday, January 5, 2010, 3:32 PM AKST (20100106/0032Z)
Source: Alaska Volcano Observatory
Notice Number: 2010/A1
Location: N 60 deg 29 min W 152 deg 44 min
Elevation: 10197 ft (3108 m)
Area: Cook Inlet-South Central Alaska
Volcanic Activity Summary: Based on the low level of seismic activity and lack of any obvious outward signs of progressing unrest, AVO is lowering the Aviation Color Code and Volcano Alert Level at Redoubt Volcano to GREEN/NORMAL.
The swarm of small, shallow earthquakes that began Sunday, December 27 has ceased and the degree of seismic activity beneath the volcano has returned to background levels. Aerial observations of the new lava dome on December 31 indicated no obvious changes at the surface and no sign of instability. Thermal images also obtained on December 31 indicate that parts of the dome are still hot, although most of the dome surface remains cold and snow covered. Magmatic gas emission from the dome area on December 31 was slightly elevated compared to the last measurement in early November, but not enough to warrant great concern.
It is likely that existing magma within the volcano's shallow plumbing system was temporarily remobilized, causing the increase in seismicity, but this process appears to have ended. It is possible for activity to resume at any time and if it does, we expect to observe a distinct increase in seismicity as well as other outward signs of unrest such as increased melting and steaming in the vicinity of the lava dome or rock fall activity on the slopes of the dome.
Remarks: AVO will continue to monitor conditions at Redoubt, but while we have no volcanoes at elevated color codes or alert levels, we will cease our usual daily reporting of activity and instead transmit a weekly summary only.
Heavily ice-mantled Redoubt volcano is located on the western side of Cook Inlet, 170 km (106 mi) southwest of Anchorage and 82 km (51 mi) west of Kenai, within Lake Clark National Park. Redoubt is a stratovolcano which rises to 10,197 feet above sea level. Recent eruptions occurred in 1902, 1966-68, 1989-90, and 2009. The 1989-90 and 2009 eruptions produced mudflows, or lahars, that traveled down the Drift River and partially flooded the Drift River Oil Terminal facility. The ash plumes produced by the 1989-90 and 2009 eruptions significantly disrupted air traffic and resulted in minor or trace amounts of ash in the city of Anchorage and other communities in south-central and interior Alaska.
Contacts: Tom Murray, Scientist-in-Charge, USGS
tlmurray@usgs.gov (907) 786-7497
Steve McNutt, Coordinating Scientist, UAF
steve@giseis.alaska.edu (907) 474-7131
Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at
http://www.avo.alaska.edu
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.
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.
Mount St. Helens has been at Volcano Alert Level NORMAL (Aviation Color Code GREEN) since July 10, 2008.
Recent Observations: Cascade Range volcano seismicity and deformation remained at background levels during the past week. No field work was scheduled. Recent upgrades to the Pacific Northwest continuous GPS network operated by the Plate Boundary Observatory (http://pboweb.unavco.org/) came online this week, enabling scientists to better monitor ground deformation in real time.
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. Hawai`i County Viewing Area status can be found at 961-8093. 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 Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH
Activity Summary for past 24 hours: Kilauea was active at two locations. At the summit, lava was visible via webcam sloshing and spattering within at least two openings in the bottom of a deep pit inset within the floor of Halema`uma`u Crater producing glow that was visible from Jaggar Overlook overnight. At the east rift zone vents, lava flowed through the upper tube system and fed surface flows that have advanced onto the coastal plain; there are no active ocean entries. Sulfur dioxide emission rates from both summit and east rift zone vents remained elevated.
Past 24 hours at Kilauea summit: Lava was visible via webcam within several small openings in the bottom of a deep pit inset with the floor of Halema`uma`u Crater; the lava surface rose out of the holes and flooded the pit bottom five times. The glow, visible from the Jaggar Museum Overlook, was the brightest since January 19, 2010.
The summit vent gas plume is moving low and to the southwest this morning. The most recent sulfur dioxide emission rate measurement was 700 tonnes/day on February 8, 2010, elevated above the 2003-2007 average of 140 tonnes/day. Small amounts of mostly ash-sized tephra continued to be carried by the ascending gas plume and deposited on nearby surfaces.
The summit tiltmeter network recorded no significant ground tilt. GPS receivers on either side of Kilauea caldera recorded extension. Seismic tremor levels have remained relatively steady and low with a few brief tremor bursts and one hybrid earthquake signal at 7:21 pm last night; tremor levels abruptly increased just after 9 pm last night and remained high with a few brief drops back to the pre-9 pm level. The number of RB2S2BL earthquakes was within background values. Five earthquakes beneath Kilauea were strong enough to be located - one beneath the southwest rift zone, two beneath the area northwest of the summit area, and two on other south flank faults.
Past 24 hours at the middle east rift zone vents and flow field: Magma degases through Pu`u `O`o crater before erupting from the TEB vent, located 2 km to the east. The most recent sulfur dioxide emission rate measurement was 1,100 tonnes/day on January 21, 2010, elevated but below the 2003-2007 average of 1,700 tonnes/day. No glow was recorded by webcam within Pu`u `O`o Crater overnight.
The tiltmeter on the north flank of Pu`u `O`o recorded no significant ground tilt. GPS receivers on either side of Pu`u `O`o Crater recorded extension of the crater. Seismic tremor levels slowly increased near the Pu`u `O`o vent and were low and steady near the TEB vent. The number of RB2S2BL earthquakes near the Pu`u `O`o and the TEB vents were within background levels.
Lava from the TEB vent flowed through the upper portion of the TEB tube system before breaking to the surface and feeding flows that were advancing slowly across the coastal plain. Yesterday, HVO geologists mapped pahoehoe lobes that advanced south about 700 m in the last 5 days from the base of the pali onto the coastal plain. GOES-WEST imagery included strong thermal anomalies on the flow field through dawn suggesting continued surface flow activity through dawn.
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:
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 even larger Kilauea caldera or crater - a crater within a crater within a crater. 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.
CD: Hawai`i County Civil Defense
RB2S2BL earthquakes: earthquakes that were recorded but were too small to be located. These quakes have magnitudes less than 1.7 and may only be recorded by one or two seismometers. Recording at a minimum of 4 seismometer sites is required to locate an earthquake.
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.
TEB: Thanksgiving Eve Breakout, the designation used for lava flows that started with a breakout on November 21, 2007.
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 eruption site, as many of the DI events at Kilauea summit are also recorded at a tiltmeter at Pu`u `O`o, delayed by 1-2 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://volcano.wr.usgs.gov/about/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 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
The Long Valley Observatory has adopted a new, easy to review, Current Condition format that will summarize noteworthy information from USGS geophysical and geochemical monitoring networks in the Long Valley region on a weekly basis. The weekly summary will appear each Friday.
Eight earthquakes between magnitude M=1.0 and M=1.9 occurred in the Long Valley region over the last week. Two of the events were located beneath the south flank of Mammoth Mountain and a third occurred under Round Mountain east of Lake Crowley. The others were located to the south of the caldera, with one earthquake in Round Valley and four others in the Sierra Nevada. This level of activity is considered normal for the area.
ANATAHAN VOLCANO (CAVW #0804-20=)
16°21' N 145°40'12" E, Summit Elevation 2592 ft (790 m)
Current Aviation Color Code: GREEN
Current Volcano Alert Level: NORMAL
Report prepared by the U.S. Geological Survey.
No reports of eruptive activity at Anatahan were received the past week, and seismic levels have remained low. Nothing unusual was observed in satellite images throughout the week.
During times of northerly winds, the Anatahan plume, if present, could be directed towards the CNMI and Guam. If this happens, residents may notice hazy air conditions and smell sulfur. The Emergency Management Office (EMO) of the CNMI government will issue volcanic haze and sulfur advisories if appropriate.
Access to the island may be restricted by the CNMI government. Contact the EMO to get the latest information.
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/
Monday, February 8, 2010 5:57 PM MST (Tuesday, February 9, 2010 0057 UTC)
Yellowstone Volcano
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
The January-February, 2010, earthquake swarm at Yellowstone National Park has diminished in terms of earthquake-occurrence rate and magnitudes. A few small events continue to be recorded each day at the University of Utah Seismograph Stations (UUSS), the YVO partner responsible for earthquake monitoring at Yellowstone National Park. Seismologists cannot state that the swarm has ceased, but the rate of earthquake occurrence in the Madison Plateau area is now at background levels for this area of Yellowstone. As such, UUSS and YVO will cease to issue daily updates unless conditions change.
As of February 8, 2010 14:00 MST, there have been 1799 events recorded by the automatic earthquake system of the University of Utah. Of those, 827 have been verified by seismic analysts and forwarded to the National Earthquake Information Center (NEIC) for incorporation in the permanent listing of earthquakes. Seismologists of the University of Utah will continue to analyze data from the past several weeks to finalize the earthquake information.
The largest events were a pair of earthquakes of magnitude 3.7 and 3.8 that occurred after 11 PM MST on January 20, 2010. Both events were felt throughout the park and in surrounding communities in Wyoming, Montana, and Idaho. Other smaller events were also reported as felt.
The earthquakes were on the Madison Plateau along the northwest side of the Yellowstone caldera, in an area where previous swarms had occurred over the past 30 years. Visual observation of landforms and geothermal features by Yellowstone National Park personnel did not show any changes that could be attributed to the earthquakes.
Yellowstone National Park is in a region of active seismicity associated with regional Basin and Range extension of the Western U.S., as well as youthful volcanism of the Yellowstone volcanic field. Pressurization due to crustal magma bodies of the Yellowstone hotspot and associated shallow geothermal reservoirs can also contribute to earthquakes. Scientists will continue to research the origin of these and other Yellowstone earthquakes.
Any new information will be posted to: http://volcanoes.usgs.gov/yvo/activity/index.php
A summary of the swarm and links to additional information can be found at: http://volcanoes.usgs.gov/yvo/publications/2010/10swarm.php
Seismic information on the earthquake can be viewed at the University of Utah Seismograph Stations: http://www.seis.utah.edu/
Seismograph recordings from stations of the Yellowstone seismograph network can be viewed online at: http://quake.utah.edu/helicorder/yell_webi.htm
---
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
