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.
Pacaya Volcano Erupts In Guatemala
Guatemala's Pacaya volcano has erupted , May 30th, sending volcanic material more than 400 metres in the air, authorities say. The Institute of Vulcanology warned that the eruption could intensify with ash rising as high as 1000 to 2000 metres, posing a threat to air traffic at Guatemala's international airport. Pacaya is one of the world's most active volcanoes. It lies approximately 25 km south of Guatemala City.
Chile, Argentina Order Evacuation of Copahue volcano
SANTIAGO/BUENOS AIRES - Chilean and Argentine authorities on Monday declared a red alert and ordered the mandatory evacuation of a 25-km (15.5-mile) radius around the active Copahue volcano, which straddles the border between the two Andean nations.
Update May 29th: The seismicity recorded during the last 24 hours showed an upward trend from the last report, registering (3134) events, most of them low magnitude hybrid type, with an average of 130 events per hour, with a gap of a few seconds between events (6-8 sec.), resembling a spasmodic tremor. Most events showed a mixture of low-frequency (1-3 Hz) with high frequencies (6-10 Hz), their size, measured by its amplitude remained stable. Its origin remains superficial in character. The maximum magnitude recorded was equal to ML = 1.4.
At the time of issuance of this report (May 28), the swarm of quakes continues. No continuous tremor signal so far.
An strong explosion was noticed today at Popocatepetl volcano. The blast threw threw incandescent fragments 1.5 kilometers from the crater on the northeast flank. The National Center for Disaster Prevention (Cenapred) said the blast created a column of ash two kilometers high, which was dispersed by the wind to the southwest.
May is Volcano Awareness Month
May is Volcano Awareness Month in Washington State. During the month of May, citizens are encouraged to take the necessary steps to find out about volcanic hazards where they live, work and play, and how to survive and recover from the next volcanic eruption. Visit the Washington State Emergency Management Division for information on how to prepare.
Various Volcanoes (May 31st) @JohnSeach reports via twitter (volcanolive.com) :
- Mayon volcano, Philippines. Blue hydrogen sulphide gas and crater glow observed. 6 km radius Permanent Danger Zone. Raised to level 1 alert.
- 3 USA volcanoes on raised alert level Kilauea (Hawaii), Pavlof (Alaska), and Cleveland (Alaska).
- Gamkonora volcano, Halmahera, Indonesia raised to level 3 alert (out of maximum 4) on 27 May
Underwater volcano mapped in Southeast Alaska May 26, 2013
Buried inside the NOAA data were 3D renderings of a previously unknown volcano, beneath the depths of Behm Canal inside Misty Fjords National Monument. The yet-to-be-named volcano differs from many on the ocean floor. Baichtal, a U.S. Forest Service geologist, says its top was likely above the water when it last erupted some 10,000 years ago. NOAA imaging and new underwater video of the area shows what appears to be leftovers of ash or cinder near the volcano crater. Read article and see picture here
The Eyjafjallajokull volcano in Iceland has finally stopped erupting, after having brought the world of flight to its knees, last month, when ash from the volcano reached 18,000 feet. However, volcanologists are not completely comfortable that there will be no further eruptions.
As Eyjafajallajokull finally quieted down, there have been 3 earthquakes
at nearby Katla volcano. Scientists have been keeping a close watch
on Katla, due to the possibility of an eruption being triggered by the activity
from Eyjafajallajokull. An eruption from Katla is expected to be several
times more powerful than its neighbour, Eyjafajallajokull.
La Garita Caldera is a large volcanic caldera located in the San Juan volcanic field in the San Juan Mountains in southwestern Colorado, United States, to the west of the town of La Garita, Colorado. The eruption that created the La Garita Caldera was, perhaps, the largest known explosive eruption in all of Earth's history (the Siberian Traps may have been larger but the cause is still being debated). The La Garita Caldera is one of a number of calderas that formed during a massive ignimbrite flare-up in Colorado, Utah and Nevada from 4025 million years ago, and was the site of truly enormous eruptions about 2826 million years ago, during the Oligocene Epoch. The area devastated by the La Garita eruption is thought to have covered a significant portion of what is now Colorado, and ash could have fallen as far as the east coast of North America and the Caribbean. The scale of La Garita volcanism was far beyond anything known in human history. The resulting deposit, known as the Fish Canyon Tuff, has a volume of approximately 1,200 cubic miles (5,000 km3), enough material to fill Lake Michigan (in comparison, the May 18, 1980 eruption of Mt. St. Helens was only 0.25 cubic miles (1.0 km3) in volume). By contrast, the most powerful human-made explosive device ever detonated, the Tsar Bomba or Emperor Bomb, had a yield of 50 megatons, whereas the eruption at La Garita was approximately 105 times more powerful. It is possibly the most energetic event on Earth since the Chicxulub impact, which was 50 times more powerful.
The California Volcano Observatory (CalVO). At Long Valley Caldera, analysis of continuous GPS data over the first half of 2012 showed a modest inflationary pattern within the caldera; ground motion was directed upward and away from the caldera's center, with a maximum uplift rate between 2 and 3 cm/yr. In January of this year at Clear Lake Volcanic Field, a short-lived swarm of low-magnitude earthquakes was detected under the south flank of Mt Konocti. For detailed info, click here
High to Very High Threat Potential
Clear Lake Volcanic Field
Lassen Volcanic Center
Long Valley Caldera
Medicine Lake
Mono-Inyo Chain
Mount Shasta
Salton Buttes
NVEWS: National Volcano Early Warning System
The National Volcano Early Warning System (NVEWS) is a proposed national-scale plan to ensure that volcanoes are monitored at levels commensurate to their threats. The plan was developed by the U.S. Geological Survey (USGS) Volcano Hazards Program (VHP) and its affiliated partners in the Consortium of U.S. Volcano Observatories (CUSVO) (http://www.cusvo.org).
Roughly half of the Nation's 169 young volcanoes are dangerous because of the manner in which they erupt and the communities within their reach. Currently, many of these volcanoes have insufficient monitoring systems (for example, seismometers and continuous GPS [Global Positioning System]), and others have outdated equipment. The NVEWS plan ensures that the most hazardous volcanoes would be properly monitored well in advance of the onset of activity, making it possible for scientists to improve the timeliness and accuracy of hazard forecasts and for citizens to take proper and timely action to reduce risk.
In addition, the NVEWS plan seeks to improve a number of capabilities of the US volcanology community through the following elements: 1) Increased partnerships with local governments and emergency responders, 2) grants to universities and other groups for cooperative research to advance volcano science, monitoring technologies, and mitigation strategies, 3) added staffing and automation to improve 24/7 monitoring of volcanoes, and 4) computer systems to distribute data to scientists, responding agencies, and the public, and to unify the systems currently used to monitor US volcanoes.
More information can be found in the documents listed here
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
Sudden explosions of blocks and ash are possible with little or no warning. Ash clouds, if produced, could exceed 20,000 feet above sea level. If a large ash-producing event occurs, nearby seismic, infrasound, or volcanic lightning networks should alert AVO staff quickly. However, for some events, a delay of several hours is possible. Cleveland Volcano does not have a local seismic network and is monitored using only distant seismic and infrasound instruments and satellite data.
PAVLOF VOLCANO (CAVW #1102-03-)
55°25'2" N 161°53'37" W, Summit Elevation 8261 ft (2518 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
No evidence of eruptive activity at Pavlof over the past day. Seismic activity remains very low. Satellite observation over the past day show slightly elevated surface temperatures, which are consistent with the cooling of the previously erupted lava. No ash or gas emissions have been detected in satellite data or reported by pilots. During past eruptions of Pavlof, the style of eruptive activity fluctuated from higher to lower levels. Therefore, this pause in eruptive activity does not necessarily indicate that the eruption has ended. Renewed activity is possible, and may not be preceded by significant seismic activity. AVO will continue to monitor Pavlof closely.
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: At the summit, tiltmeters recorded inflation until 7 PM last night, when DI deflation started. The lava lake level began to drop with the deflation. At the middle east rift zone, the Kahauale`a II lava flow remained active north of Pu`u `O`o. Southeast of Pu`u `O`o, the Peace Day flow had active breakouts on the pali and coastal plain, but most of the flow stayed within its lava tube until reaching the ocean on both the east and west sides of the Hawai`i Volcanoes National Park boundary. Gas emissions from the volcano remained elevated.
Recent Observations at Kilauea summit: After 3 days of inflation, the summit tiltmeter network recorded the onset of DI deflation at about 7 PM last night (May 31). The summit lava lake began to drop at the same time and continues to fall this morning. The most recent sulfur dioxide emission rate measurement was 1000 t/d on May 24, 2013; this value is a minimum because the data are acquired close to the vent where the plume is most dense and challenging to fully characterize. Though not measured today, a very small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair) was probably carried aloft by the plume and deposited onto nearby surfaces.
Seismic tremor levels were low and relatively steady, except for one short-lived drop to an even lower level mid-day yesterday. Seven located earthquakes occurred beneath Kilauea Volcano in the past 24 hours - four were on south flank faults, one was in the east rift zone, and two were beneath the southern end of the summit caldera. GPS receivers spanning the summit have recorded only small variations, probably related to DI events, since mid-May.
May 21st marked the 10,000 day of current eruption on the east rift zone
of Kilauea volcano in Haiwaii, which began erupting on the 3rd January,
1983. The Halemaumau crater at the summit has been erupting since 9th March,
2008. Lava is currently flowing into the sea west of Kalapana.
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KILAUEA VOLCANO (CAVW #1302-01-)
19°25'16" N 155°17'13" W, Summit Elevation 4091 ft (1247 m)
Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
For updated status: http://hvo.wr.usgs.gov/activity/kilaueastatus.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/
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.
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
Yellowstone Map and current information 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.
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.
On Going Activity/Unrest: http://www.volcano.si.edu/reports/usgs/
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.
For a webcam view of the volcano: http://www.fs.fed.us/gpnf/volcanocams/msh/
Mount St. Helens Eruption Highlights 2004 - Present
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
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
At Long Valley Caldera, analysis of continuous GPS data over the first half of 2012 showed a modest inflationary pattern within the caldera; ground motion was directed upward and away from the caldera's center, with a maximum uplift rate between 2 and 3 cm/yr. In January of this year at Clear Lake Volcanic Field, a short-lived swarm of low-magnitude earthquakes was detected under the south flank of Mt Konocti.
Earthquake Swarm in the Brawley Seismic Zone : August 27, 2012
An energetic earthquake swarm (largest event magnitude 5.5) is ongoing in the Brawley Seismic Zone south of the Salton Sea in Southern California. The swarm started on Saturday August 25 with earthquake activity on a northeast striking fault zone located about 20 km (12.5 miles) south of the young volcanic center known as Salton Buttes. The most recent eruptions, which took place about 9,000 years ago, produced five rhyolite lava domes along the present-day shore of the southern Salton Sea. The Brawley Seismic Zone, located between the northern end of the Imperial Fault and the southern end of the San Andreas Fault is a tectonically active area, with numerous earthquake swarms occurring over the last several decades, most recently in 2005 and in 1981. There is no evidence to suggest the present swarm is volcanic in nature. More information on the Brawley swarm can be found on the website of the Southern California Seismic Network (a partnership of Caltech and the USGS) at http://www.scsn.org. Visit the Salton Buttes page to learn more about the Salton Buttes volcanic area.
Maps
of Long Valley Caldera and Mono-Inyo Craters Volcanic Chain, California
