Volcanic Activity ReportEarth Changes News |
The alert-level system for all volcanoes monitored by the USGS was changed on 1 October from a numerical system to a descriptive system. In the new system, alert-level Normal indicates background conditions and is equivalent to aviation color-code Green. The previous alert levels of Volcanic Unrest (Alert Level 1), Volcano Advisory (Alert Level 2) and Volcano Alert (Alert Level 3) have changed to "Advisory," "Watch," and "Warning," respectively. There is a subtle change to the aviation color-code definitions in that there is no longer an ash-plume threshold given for either Orange or Red. Watch; Aviation color code ORANGE." The alert-level "Watch" is used for two different situations: (1) heightened or escalating unrest indicating a higher potential that an eruption is likely, but still not certain; or (2) an eruption that poses only limited hazard.
ABBREVIATED COLOR CODE KEY :
GREEN volcano is dormant; normal seismicity and fumarolic activity occurring = Normal
YELLOW volcano is restless; eruption may occur
ORANGE volcano is in eruption or eruption may occur at any time
RED significant eruption is occurring or explosive eruption expected at any time
Kamchatkan and Northern Kuriles Volcanic Activity
Volcanoes
of the Kurile Islands Activity
Preparing for Natural Disasters and Weather Emergencies
Natural disasters are the effect of natural hazards, such as avalanches, blizzards, floods, tornadoes, hurricanes, volcanic eruptions, earthquakes, and wildfires. These unexpected events lead to financial, environmental loss, as well as loss of animal and human life. Natural disasters can occur due to an individual's lack of preparedness, which leaves them vulnerable to uncontrollable forces. A natural hazard distinctly means a natural phenomena that has not resulted in significant damage or loss of life. Some key points of preparedness involve securing one's home, developing an evacuation plan, and storing enough food and water to survive long periods of tumultuous activity.47-*9++++
Mount Etna spews lava in spectacular show |
MOUNT ETNA, Italy - Europe's only active volcano, Mount Etna, put on a spectacular display on Monday evening (April 23) with red hot lava spewing metres up into the night-time sky. |
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March 26, 2012 Santiago de Chile Chilean authorities maintain state of alert in the Araucania region, due to increased seismic activity at Llaima volcano, one of the most active in the country and in South America. The regional governor, Andres Molina, confirmed that a yellow alert continues to be in effect for the communities of Melipeuco, Cunco, Vilcún, Curacautín and Lonquimay, because there are clear signs of "out-gassing in the inner perimeter" of the Llaima. Molina said that on Monday will meet the emergency committee to assess the status of the volcano, then it is found that in recent weeks the number quakes have tripled within the massif, which is located in the Andes, about 600 kilometers south of this capital. In geology, a massif is a section of a planet's crust that is demarcated by faults or flexures. The regional authority also noted that access was restricted in a radius of four kilometers around the volcano, especially in the tourist area of Conguillío Park, where last weekend, authorities evacuated over a hundred people. According to records provided by the expert technicians Fernando Gil, Volcano Observatory of the Southern Andes, one cannot rule out an eruption and although volcanic activity cannot be perceived by the inhabitants of the towns that are on yellow alert. The Llaima, more than three thousand meters in elevation, is located 76 kilometers northeast of the city of Temuco, capital of the region of La Araucania. The Llaima volcano last erupted in 2009. On March 25, a 7.1 magnitude earthquake struck northeast of the region at a depth of about 35 km (21 miles) and this may further acerbate the volcanic belt of this region of Chile. Prensa Latina (translated) |
CLEVELAND VOLCANO (CAVW #1101-24-) Alaska
Tues, April 24, 2012
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
2012-04-24 11:43:36 - Status Report
The low-level eruption of Cleveland Volcano continues. Satellite images from the last 24 hours show cloudy to mostly cloudy conditions at the volcano.
While the volcano remains active, sudden explosions of blocks and ash are likely. It is possible for associated ash clouds to exceed 20,000 feet above sea level. If a larger ash-producing event occurs, seismic, infrasound, or volcanic lightning networks should detect the event and alert AVO staff. There is no real-time seismic monitoring network on Mount Cleveland so AVO is unable to track activity in real time.
May 21, 2011 YELLOWSTONE NATIONAL PARK, Wyoming - The world's most dangerous volcano is moving - The nation's oldest park is also one of the most studied. The interest is not just in its amazing vistas and wildlife, but in the volcanic beast below the park. Yellowstone sits atop one of the world's biggest, active volcanoes, one capable of laying waste to much of North America. Scientists keep an eye on it using a network of seismic and GPS sensors. Professor Emeritus Robert Smith of the University of Utah is one of those scientists. A geophysicist, Smith a leading expert on the Yellowstone super volcano. "We monitor it in real time for earthquake swarms and ground deformation." He says the park is in constant motion. Visitors can't see it, but the ground at their feet is moving up and down as magma pushes against the thin crust and powers the park's many geysers. The changes are most evident at the Norris Geyser Basin. Henry Heasler, the Yellowstone Park geologist said, "It changes daily. Sometimes it's hard to keep up with the change near boardwalks because that impacts visitor and employee safety.Why are all the hydrothermal features here?" Heasler continued, "The geysers? The mud pots? The steam vents? The hot springs? It's because of the heat beneath our feet." The heat from the volcano is the culprit. And beginning in 2004, volcanic pressure caused an amazing rise at the park: Three-inches a year for five-years. Professor Smith said, "That's a lot of uplift and it's over an area that's over the entire Yellowstone caldera - 50-miles long of uplift." "If you went under a rubber sheet," Heasler said describing the uplift, "And pushed your thumb up, it's not just sticking up where your thumb is, there's like a slope to it." In fact, as the land has bulged, Yellowstone lake has tilted enough that its water has flooded out trees on the south arms. And now, the ground is sinking. And the drop has brought up a whole new set of questions for scientists. "Why haven't the trees emerged again?" asked Heasler. "We don't know." They are watching the data as well as the geothermal features of the park for clues. At times, those geologists see themselves are doctors monitoring a patient. In this case, the patient took a deep breath (between 2004-09) and now it is letting it out. That much is clear from the observations. The unanswered question is, "why?" ABC News
Nevada: I know many of you have been watching the earthquake swarm near Hawthorne, Nevada with some interest. There have been over 400 earthquakes near the Nevada town over the last few weeks and no one is quite sure what the source of the seismicity might be. There is the interesting coincident that the focus of the swarm is near the Aurora Volcanic Field - however, Graham Kent from the director of the Nevada Seismological Lab at the University of Nevada, Reno, doesn't think a volcanic eruption is likely (note: the Nevada TV station for this link decided to post video from "Volcano" with the story...sigh.) Even if there was an eruption, it would likely be something small, such as a small cinder core or fissure lava flow based on the previous activity at the Aurora Field, which hasn't been active for 250,000 years. However, that being said, Nevada is still a volcanically-active state, with a number of locations that could see new volcanic activity. Also, Nevada has seen many earthquake swarms over the past few years, and none have lead to volcanic activity - that is like in the Basin and Range province. source
Scientists are using infrared images to track potentially deadly patterns of heat in the Earth in and around active volcanoes. One aim: to save lives by predicting eruptions.
Giant Undersea Volcano Found Off Iceland
National Geographic News - April 22, 2008: A giant and unusual underwater volcano lies just offshore of Iceland on the Reykjanes Ridge, volcanologists have announced. The Reykjanes formation is a section of the Mid-Atlantic Ridge, which bisects the Atlantic Ocean where the North American and Eurasian tectonic plates are pulling apart.
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ScienceDaily (Dec. 3, 2009) - Hawaii may be paradise for vacationers, but for geologists it has long been a puzzle. Plate tectonic theory readily explains the existence of volcanoes at boundaries where plates split apart or collide, but mid-plate volcanoes such as those that built the Hawaiian island chain have been harder to fit into the theory. A classic explanation, proposed nearly 40 years ago, has been that magma is supplied to the volcanoes from upwellings of hot rock, called mantle "plumes," that originate deep in the Earth's mantle. Evidence for these deep structures has been sketchy, however. Now, a sophisticated array of seismometers deployed on the sea floor around Hawaii has provided the first high-resolution seismic images of a mantle plume extending to depths of at least 1,500 kilometers (932 miles).
January 2010 Proclaimed Volcano Awareness Month - January 3, 2010, marks the 27th anniversary of K?lauea's ongoing east rift zone eruption. In 2010, it will also be 20 years since Kalapana was buried beneath lava and 50 years since Kapoho was inundated by fast-moving lava flows. The destruction of these two communities is a sobering reminder of why it's important to understand how Hawai'i's volcanoes work.
Volcanoes are integral to life on Hawai'i Island. Volcanoes provide the soils in which we grow coffee, macadamia nuts, and other agricultural products, and supply energy for our electricity. When they erupt, they can be spectacularly beautiful, mesmerizing both residents and visitors who are lucky enough to witness the drama.
Volcanoes were so significant to early Hawaiian settlers that an entire theology-the goddess Pele and her family-was founded on them. Today, as in the past, awareness is essential for us to live in harmony with the volcanoes that make our island home.
HAWAIIAN VOLCANO OBSERVATORY UPDATE
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
Tues April 24, 2012
Activity Summary for past 24 hours: DI deflation started yesterday afternoon preceded by a slow drop in summit lava lake level. Glow from the summit lava lake lit up the Halema`uma`u gas plume overnight. At Pu`u `O`o, glow persisted from the usual sources within the crater. To the southeast, surface flows continued to spread on the coastal plain but there was no ocean entry. Seismic tremor levels were low; gas emissions were elevated.
Past 24 hours at Kilauea summit: The lava lake level started dropping at noon yesterday and the summit tiltmeter network recorded the start of DI deflation just after 4 pm; it is rare, but not the first time, that the lava lake drop preceded the DI deflation by so much time. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on April 23, 2012. Small amounts of ash-sized tephra, including fresh bits of spatter from the active lava source at the southeast edge of the lava lake, were wafted out of the vent within the gas plume and deposited on nearby surfaces.
Since mid-October 2011, the summit GPS network recorded ~1 cm/mo extension indicating continuing long-term summit inflation. Seismic tremor levels remained low. Four earthquakes were strong enough to be located beneath Kilauea volcano: 2 within the upper east rift zone and 2 deep quakes on south flank faults.
Background: The summit lava lake is deep within a ~160 m (520 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: Within Pu`u `O`o crater, glow could be seen from a small collapse pit and spatter cone on the northeast edge and spatter cone on the southeast edge of the floor; glow could also be seen from the uppermost tube system on the east flank of Pu`u `O`o cone; the public Webcams viewing Pu`u `O`o crater should be operational late this week. Seismic tremor levels near Pu`u `O`o were low. The tiltmeter on the north flank of Pu`u `O`o cone recorded continued inflation with possible DI deflation starting at 6:30 am this morning. GPS receivers on opposite sides of the cone continued to show neither extension nor contraction. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on February 17, 2012, from all east rift zone sources.
The east and west lobes have stalled at the base of the pali but remain active near the top of the pali probably above 1,000 ft elevation. The leading edge of the flows are around 7 km (4 mi) southeast of Pu`u `O`o. There are no active flows on the coastal plain or entering the ocean.
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 but the flows have remained intermittently active above or on the pali. 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 within the Royal Gardens subdivision; the lava flows 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) and the evacuated Royal Gardens subdivision, which can only be viewed from the air. Under favorable weather conditions, the flows can be seen from the County Viewing Area at Kalapana and in the Holei webcam. 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
The most recent (preliminary) sulfur dioxide emission rate measurement was 800 tonnes/day on August 4, 2011. Small amounts of ash-sized tephra, including fresh spatter bits, continued to be wafted within the plume and deposited on nearby surfaces.
Background: The summit lava lake is deep within a ~150 m (500 ft) diameter
near-vertical cylindrical vent inset within the east wall and floor of Halema`uma`u
Crater. The vent has been mostly active since opening with a small explosion
on March 19, 2008.
Definitions of terms used in the update:
HAVO: Hawai`i Volcanoes National Park
UHH: University of Hawai`i at Hilo
glow: light from an unseen source; indirect light.
FLIR: Forward Looking InfraRed, a camera which directly images heat rather than visible light. If volcanic fume is not too rich in water vapor, a FLIR can see through it to image hot surfaces.
pali: Hawaiian word for cliff or steep incline. In the context of the TEB flow field, 'pali' usually refers to Pulama pali that bisects the abandoned Royal Gardens subdivision.
CD: Hawai`i County Civil Defense
DOH air quality monitoring: see Hawai`i State Department of Health Air Quality website http://hawaii.gov/doh/air-quality/index.html .
bomb: lava fragment ejected into the air while molten acquiring aerodynamic shapes in flight; the term is restricted to pieces larger than 6.4 cm (2.5 in.). See http://volcanoes.usgs.gov/Products/Pglossary/bomb.html
hybrid, or explosion, seismic signals: complex earthquakes that are a hybrid of different signals. They start as a high frequency earthquake, similar to typical rock-breaking or rock fall events, that transitions to very long, 20-30 second, period (VLP) oscillations that continue for several minutes. At HVO, we observed these signals with the four small Halema`uma`u explosive eruptions in March, April, and August 2008. Several more similar signals, some as strong as the explosion signals associated with the four explosive eruptions, have been recorded without obvious evidenceof surface eruption such as rock fragments or other debris.
MODIS satellite: a NASA satellite pair, Aqua and Terra, which passes over Hawai`i twice a day. During daylight hours, the images are taken at about 11 am and 2 pm H.s.t. This imagery can be viewed about 3-5 hours after acquisition at http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Mauna_Loa.
GOES-WEST satellite: a geostationary NOAA satellite used most often for weather tracking. Images are typically acquired every 15 minutes. The loop http://www.ssd.noaa.gov/VAAC/kilauea/sloop-vis.html is posted by the Washington DC Volcanic Ash Advisory Center for the purpose of tracking emissions from Hawai`i volcanoes. The imagery automatically switches from infrared at night to visual during the day. Recently, it has been useful for tracking volcanic gas emissions from Halema`uma`u, Pu`u `O`o, and the Waikupanaha ocean entry during the day and hot lava flows at night.
Volcano Watch: weekly newspaper-like article written by HVO scientists on a volcano topic of interest. These articles are usually printed in the Sunday editions of the Hawai`i Island newspapers Hawaii Tribune Herald and West Hawaii Today. More than 800 of these articles have been written and are archived on the HVO website (menu at the bottom of the homepage hvo.wr.usgs.gov).
VLP seismic tremor: seismic tremor is continuous ground vibrations simultaneously at many different frequencies. VLP is a very long period or very low frequency component which, at the Halema`uma`u vent, has a period of 20-30 seconds or a frequency of 0.03-0.05 cycles per second (Hertz or Hz).
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.
wink: an abrupt shutting off of incandescence at a vent lasting for several minutes. At the Halema`uma`u vent, winks usually start with or immediately follow a small, local earthquake. The diminishment of incandescence is due to the plume changing from translucent to opaque with rock dust.
tonne: metric unit equal to 1,000 kilograms, 2,204.6 lbs, or 1.1 English tons.
microradian: a measure of angle equivalent to 0.000057 degrees.
ppm: parts-per-million; 10,000 ppm = 1 %.
littoral cone: usually small cones built near active ocean entries; the cones are constructed of tephra from steam explosions that are sometimes produced when 1,150 degree C lava enters the 25 degree C ocean.
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).
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.
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.
Maps, photos, webcam views, and other information about Kilauea Volcano are available at http://volcano.wr.usgs.gov/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
Listen to a podcast interview with Dr. Eichelberger describing the activity at Kilauea in episode 35 of CoreCast at http://www.usgs.gov/corecast/.
21-Nov-2006: Volcanic eruptions in high latitudes can greatly alter climate and distant river flows, including the Nile, according to a recent study funded in part by NASA. Researchers found that Iceland's Laki volcanic event, a series of about ten eruptions from June 1783 through February 1784, significantly changed atmospheric circulations across much of the Northern Hemisphere. This created unusual temperature and precipitation patterns that peaked in the summer of 1783, including far below normal rainfall over much of the Nile River watershed and record low river levels. Full Article Here
ScienceDaily (Dec. 14, 2009) - The most detailed seismic images yet published of the plumbing that feeds the Yellowstone supervolcano shows a plume of hot and molten rock rising at an angle from the northwest at a depth of at least 410 miles, contradicting claims that there is no deep plume, only shallow hot rock moving like slowly boiling soup.
The Journal of Volcanology and Geothermal Research recently (20 November 2009) published a special volume on the track of the Yellowstone Hot Spot.
Listing of articles for preview and purchase
By Andrea Thompson, LiveScience Staff Writer: 08 November 2007 02:00 pm ET
Yellowstone's ancient volcanic floor has been rising since mid-2004 because a blob of molten rock the size of Los Angeles infiltrated the system 6 miles beneath the surface, scientists say, but there is no risk of an eruption.
Yellowstone National Park is the site of North America's largest volcanic field, which is produced by a hotspot, or gigantic plume of hot, molten rock, that begins at least 400 miles (643 kilometers) beneath Earth's surface and rises to 30 miles (48 kilometers) underground, where it widens to about 300 miles across.
Updates are compiled for the previous month and posted in the first week of the new month.
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Thursday, March 1, 2012 2:32 PM MST (Thursday, March 1, 2012 21:32 UTC)
During the month of February 2012, the University of Utah Seismograph Stations, reported that 34 earthquakes were located in the Yellowstone National Park region. The largest was a magnitude 1.6 event on February 23 at 12:57 PM MST, located about 9 miles north northeast of Old Faithful, YNP. There were no independent swarms of earthquakes.
Yellowstone earthquake activity continues at relatively low background levels.
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
Earthquake activity continues at relatively low background levels. For a map of recent earthquakes, please see:http://www.seis.utah.edu/req2webdir/recenteqs/Maps/Yellowstone.html
Ground Deformation Summary: The period of caldera uplift that began in
2004 ended over one year ago. Since then, the caldera has been subsiding,
though seasonal deformation from ground water changes may temporarily mask
the trend. 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_plotseries=raw.
An article on the recent uplift episode at Yellowstone and discussion
of long-term ground deformation at Yellowstone and elsewhere can be found
at: http://volcanoes.usgs.gov/yvo/publications/2007/upsanddowns.php
Summary of January - February 2010 Yellowstone Earthquake Swarm- The rate of earthquake occurrence in the Madison Plateau area is now at background levels. The swarm began on January 17, 2010 around 1:00 PM MST about 10 miles (16 km) northwest of the Old Faithful area on the northwestern edge of Yellowstone Caldera. Swarms have occurred in this area several times over the past two decades.
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
Ground Deformation Summary: Continuous GPS data show that uplift of the Yellowstone Caldera has slowed significantly and may have stopped. The WLWY station, located in the northeastern part of the caldera, underwent a total of ~23 cm of uplift between mid-2004 and mid-2009. Its record can be found at:
http://pboweb.unavco.org/shared/scripts/stations/?checkkey=WLWY&sec=timeseries_plots×eries=raw
The general uplift and subsidence of the Yellowstone caldera is of scientific importance and will continue to be monitored closely by YVO staff.
An article on the recent uplift episode at Yellowstone and discussion of long-term ground deformation at Yellowstone and elsewhere can be found at: http://volcanoes.usgs.gov/yvo/publications/2007/upsanddowns.php
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The currently observed reduction in uplift rate may be related to seasonal changes related to snowmelt and groundwater recharge. In several of the past 5 years, such changes have caused decreased uplift or slight subsidence, but were followed later in the year by continued uplift. The general uplift of the Yellowstone caldera is of scientific importance and will continue to be monitored closely by YVO staff.
An article on the current uplift episode at Yellowstone and discussion
of long-term ground deformation at Yellowstone and elsewhere can be found
at: http://volcanoes.usgs.gov/yvo/publications/2007/upsanddowns.php
An article on the recent earthquake swarm during December 2008 and January 2009 can be found at:
http://volcanoes.usgs.gov/yvo/publications/2009/09swarm.php
Scientists continue to look at data collected during the swarm and will publish their results over the coming months and years. However, if any findings have direct implications for public safety, they will be released to the public immediately.
The Journal of Volcanology and Geothermal Research recently (20 November 2009) published a special volume on the track of the Yellowstone Hot Spot
Monday, February 2, 2009 10:52 MST (Monday, February 2, 2009 17:52 UTC)
Seismicity Summary: As of January 8, 2009, the seismic activity has markedly decreased. Beginning Dec 26, 2008, the second largest earthquake swarm of Yellowstone's recorded seismic history occurred beneath the north end of Yellowstone Lake. The swarm continued into Jan. 2009, but subsided rather quickly in activity on January 5. The Lake swarm consisted of 813 well-located earthquakes with magnitudes ranging from -0.8 to 3.9. This sequence contained 19 earthquakes of M>3.0 as well as 141 events of 2<M<2.9. Several of the M>3 swarm events were felt throughout Yellowstone National Park and surrounding area. For the entire month of January, 2009 315 earthquakes were located with 205 of these events associated with the Yellowstone Lake swarm, the largest being M 3.5 on January 2 at 11:32 AM MST. There have not been any reports of damage from the Yellowstone Lake swarm. Note that the largest earthquake swarm recorded in Yellowstone began in the autumn of 1985 on the west side of the caldera and east of West Yellowstone MT. It lasted for ~4 months and contained earthquakes of M>4.
In Jan. 9 to Jan 12, a secondary swarm of 35 earthquakes occurred near the northeast edge of the Yellowstone caldera, about 10 miles (16 km) NNE of the north end of the Yellowstone Lake swarm. This sequence included events with magnitudes of 0.4 to 3.3.
For comparison, Yellowstone commonly experiences 1,000 to 3,000 earthquakes per year and there have been more than 32,000 well-recorded earthquakes in Yellowstone from 1973 to 2009. Earthquakes that are closely spaced in time and area are termed swarms and are a common mode of seismic energy release in the Yellowstone caldera. From 1984 to 2008 there were 80 swarms documented in Yellowstone. The last notable swarm occurred in 2004.
Earthquake activity in the Yellowstone was elevated during the Yellowstone Lake swarm but has returned to relatively normal background levels.
Yellowstone Volcano Observatory partners continue to analyze the seismic and ground deformation data from the Yellowstone Lake swarm and are evaluating any changes to the thermal areas located near the epicenters. If any changes are to be verified, they are quite small.
Ground Deformation Summary: Through January 2009, continuous GPS data show that much of the Yellowstone caldera continued moving upward, though at a lower rate than the past several years. The nearest GPS station to the swarm, at Lake Jct., about 2 km from the swarm has experienced ground uplift over the past 55 months of about ~18 cm (A plot of the vertical and horizontal ground motions at the Lake GPS station can be found at: http://pboweb.unavco.org/shared/scripts/stations/?checkkey=LKWY&sec=timeseries_plots×eries=raw). The WLWY station has undergone ~21 cm of uplift over the same time period. These and all other Yellowstone GPS data are being analyzed for unusual properties that may be associated with the Yellowstone Lake swarm. The general uplift of the Yellowstone caldera is of scientific importance and will continue to be monitored closely by YVO staff.
An article on the current uplift episode at Yellowstone and discussion of long-term ground deformation at Yellowstone and elsewhere can be found at: http://volcanoes.usgs.gov/yvo/publications/2007/upsanddowns.php.
Small Earthquake Swarm on 9 January 2009 near northeast corner of Yellowstone Caldera
A currently modest swarm of earthquakes began in the northeast corner of the Yellowstone Caldera, about 10 miles (16 km) NNE of the north end of the Yellowstone Lake swarm that was active in late December and early January. As of 1930 MST, 10 earthquakes had been located by the University of Utah Seismograph Stations, the largest with M= 3.3 and two other events with M >2.0. Located depths are between 2 and 4 km.
Yellowstone Volcano Observatory staff and collaborators are analyzing the data from this and from the earlier Yellowstone Lake swarm and are checking for any changes to the thermal areas located near the epicenters. We will provide further information as it becomes available.
Yellowstone Lake Earthquake Swarm Summary as of 8 January 2009
Image 1. Yellowstone Lake showing location and times of the recent earthquakes from Dec. 27, 2008 (blue) to Jan. 8, 2009 (red). The M 3.0 and greater earthquakes are shown as stars, the smaller earthquakes are shown as circles. During the swarm, the earthquake locations appear to have moved north. |
Earthquake Summary:
Yellowstone seismicity increased significantly in December 2008 due to an energetic earthquake swarm that commenced on December 26. This swarm, a sequence of earthquakes clustered in space and time, is occurring beneath the northern part of Yellowstone Lake in Yellowstone National Park. As of this writing, the largest of these earthquakes was a magnitude 3.9 at 10:15 pm MST on Dec. 27. Through 5:00 pm MST on Dec. 31, the sequence had included 12 events of magnitude 3.0 to 3.9 and approximately 20 of magnitude 2.5 to 2.9, with a total of at least 400 events large enough to be located (magnitude ~1 or larger). National Park Service (NPS) employees and visitors have reported feeling the largest of these earthquakes in the area around Yellowstone Lake and at Old Faithful and Grant Village.
The hypocenters of the swarm events cluster along a north-south-trending zone that is about 7 km long. The vast majority of the focal depths are shallower than 5 km. It is not possible to identify a causative fault of other feature without further analysis.
Analysts are currently processing the backlog of seismic data from these events. The current analyst-processed catalog is believed to include all events of magnitude 2.5 and greater through Dec 31 at 5 pm MST, but hundreds of earthquakes remain to be processed. The total of more than 400 locatable events is based on automatically-determined locations and magnitudes for the swarm events.
The December 2008 earthquake sequence is the most intense in this area for some years. No damage has been reported within Yellowstone National Park, nor would any be expected from earthquakes of this size. The swarm is in a region of historical earthquake activity and is close to areas of Yellowstone famous hydrothermal activity. Similar earthquake swarms have occurred in the past in Yellowstone without triggering steam explosions or volcanic activity. Nevertheless, there is some potential for hydrothermal explosions and earthquakes may continue or increase in magnitude. There is a much lower potential for related volcanic activity.
The National Park Service in Yellowstone has been kept fully informed of the ongoing seismic activity via electronic means and by phone contacts with the University of Utah and the U.S. Geological Survey USGS). The Wyoming Office of Homeland Security is reviewing Earthquake Response Plans and monitoring seismic activity.
Earthquakes are a common occurrence in the Yellowstone National Park area, an active volcanic-tectonic area averaging 1,000 to 2,000 earthquakes a year. Yellowstone's 10,000 geysers and hot springs are the result of this geologic activity. A summary of Yellowstone's volcanic history is available on the Yellowstone Volcano Observatory web site (listed below).
The University of Utah operates a seismic network in Yellowstone National Park in conjunction with the National Park Service and the U.S. Geological Survey. These three institutions are partners in the Yellowstone Volcano Observatory. Seismic data from Yellowstone are transmitted to the University in real-time by radio and satellite links from a network of 28 seismographs in the Yellowstone area and are available on the web.
Seismologists continue to monitor and analyze data from this swarm of earthquakes and provide updates to the NPS and USGS and to the public via the following web pages. Information on U.S. earthquake activity including Yellowstone can be viewed at the U.S. Geological Survey web site: http://earthquake.usgs.gov/eqcenter/recenteqsus/.
Information on earthquakes can also be viewed at the University of Utah Seismograph Stations web site: http://www.seis.utah.edu/.
Seismographic recordings from Yellowstone seismograph stations can be viewed online at: http://www.quake.utah.edu/helicorder/heli/yellowstone/index.html.
An article on earthquake swarms at Yellowstone is available at the following: http://volcanoes.usgs.gov/yvo/publications/2004/apr04swarm.php
Geologic information, maps, and monitoring information for Yellowstone can be found on the Yellowstone Volcano Observatory web site at: http://volcanoes.usgs.gov/yvo/.
Ground Deformation Summary:
Through December 2008, continuous GPS data show that much of the Yellowstone caldera continued moving upward, though at a lower rate than the past few years. The maximum measured ground uplift over the past 53 months is ~23 cm at the White Lake GPS station, north of Fishing Bridge. An example can be found at: http://pboweb.unavco.org/shared/scripts/stations/?checkkey=WLWY&sec=timeseries_plots×eries=raw.
The general uplift of the Yellowstone caldera is scientifically important
and will continue to be monitored and studied closely by YVO staff. A discussion
of the current uplift episode at Yellowstone and long-term ground deformation
at Yellowstone and elsewhere can be found at: http://volcanoes.usgs.gov/yvo/publications/2007/upsanddowns.php.
Earthquake Magnitude ranging from barely felt into the 3.6 mag. range have been swarming since Dec. 26, 2008. On Jan. 1, 2009 there have been 241 earthquakes registering in this swarm at 44 degress North, 110 degrees West. For an updated list of this activity, click here.
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: Seismometers recorded additional rockfalls from the Nisqually Cleaver on the south side of Mount Rainier. This area produced several large snow and rock avalanches in late June. The summer field season is in full swing. Several crews worked at Mount St. Helens on Wednesday repairing and upgrading monitoring equipment and conducting gas-measurement experiments.
For a webcam view of the volcano: http://www.fs.fed.us/gpnf/volcanocams/msh/
A
Volcano Rekindled: The Renewed Eruption of Mount St. Helens, 2004-2006 November 22, 2006
The current eruption of Washington State's Mount St. Helens, which began about two years ago, has been marked by a series of weak, shallow earthquakes, or "drumbeats," that occur every couple of minutes, a new study says. The "slip/stick" motion of the rocky "plug" being pushed out of the volcano is causing those rhythmic quakes, according to scientists from the Cascades Volcano Observatory in Vancouver, Washington
Oct. 3 , 2006: In June 1912, Novarupta-one of a chain of volcanoes on the Alaska Peninsula-erupted in what turned out to be the largest blast of the twentieth century.Almost a hundred years later, researchers are paying attention. Novarupta is near the Arctic Circle and its impact on climate appears to be quite different from that of "ordinary" tropical volcanoes, according to recent research by climatologists using a NASA computer model.
When a volcano anywhere erupts, it does more than spew clouds of ash, which can shadow a region from sunlight and cool it for a few days. It also spews sulfur dioxide. If the eruption is strongly vertical, it shoots that sulfur dioxide high into the stratosphere more than 10 miles above Earth.
Up in the stratosphere, sulfur dioxide reacts with water vapor to form sulfate aerosols. Because these aerosols float above the altitude of rain, they don't get washed out. They linger, reflecting sunlight and cooling Earth's surface.
This can create a kind of nuclear winter (a.k.a. "volcanic winter") for a year or more after an eruption. In April 1815, for instance, the Tambora volcano in Indonesia erupted. The following year, 1816, was called "the year without a summer," with snow falling across the United States in July. Even the smaller June 1991 eruption of Pinatubo in the Philippines cooled the average temperature of the northern hemisphere summer of 1992 to well below average.
But both those volcanoes as well as Krakatau were in the tropics.
Novarupta is just south of the Arctic Circle.
For Complete Story - http://science.nasa.gov/headlines/y2006/03oct_novarupta.htm
Friday, August 26, 2011
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
August 26, 2011 - Forty-seven earthquakes occurred in the Mammoth Lakes-Long Valley caldera region in the past week. The most notable, a magnitude 4.2, occurred on August 24 at 4:59 AM. The quake, which produced weak-to-light shaking in Yosemite Village, Mammoth Lakes, Bishop, and Big Pine, was located in the Sierra Nevada about 9 miles SE of of the town of Mammoth Lakes. The event was followed by many aftershocks, but only one of these was above 2.0. Earthquakes were also detected elsewhere in the Sierra south of the caldera (all below magnitude 2.0) and at Mammoth Mountain (3 events all less than magnitude 1.0), in the caldera (a single magnitude 1.0 earthquake ), and in the Volcanic Tableland E-SE of Toms Place (a magnitude 2.5 earthquake).
Maps
of Long Valley Caldera and Mono-Inyo Craters Volcanic Chain, California
