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.
November 20, 2011 - Mexico's Popocatepetl volcano spewed a burst of ash 3 miles (5 kilometers) into the air after magma broke through a dome of lava. Mexico's National Disaster Prevention Center says Sunday's explosion continues a series of moderate eruptions from the 17,886-foot (5,450-meter) volcano 40 miles (65 kilometers) southeast of the Mexican capital. The Disaster center says the volcano has been emitting small but steady streams of steam and gas since Friday. Mexico City Civil Protection Director Elias Moreno told Foro Television that there were no reports of danger or of ash falling on nearby communities. Popocatepetl has been erupting intermittently since December 1994.
Saturday 19th November 2011 - Nyamuragira Volcano, Democratic Republic of Congo Eruption at Nyamuragira volcano in the Democratic Republic of Congo has created fissures and lava flows which extend over a distance of 11.5 km. Lava fountains continue and lava flows are advancing northwards and have reached within 5 km of Kalengera-Tongo road. The rate of advance of the lava flow has decreased over the past week. The eruption has not affected Gorillas in the Virunga Ranges which are located 20 km from the eruption site. There has been no effect on the Tongo Chimpanzees.
Saturday 19th November 2011 - Hierro Volcano, Canary Islands Earthquake activity has increased at El Hierro volcano, Canary Islands. A magnitude 3.7 earthquake occurred at 15:32 hr (UT) on 18th November in the El Golfo region. The focus was at a depth of 23 km. Between midnight and 14:30 hr there were 32 earthquakes. Beaches between Puerto Naos and La Restinga have been closed due gas emissions. A 4 km radius around the eruption site is closed to navigation. Area of upwelling is over 200 m in diameter.
Nyamuragira volcano erupting in the Congo - Nov. 7th The Nyamulagira volcano has been erupting since Sunday around 8:30 p.m., says the Goma Volcano Observatory. Nyamulagira volcano, located 22 km from the city of Goma, capital of the province of North Kivu, in the eastern part of the Democratic Republic of the Congo (DRC), is one of eight active volcanoes that make up the Virunga chain in the Virunga National Park in eastern DRC. Le Nyamulagira volcano erupts at intervals of about 2 years. http://theextinctionprotocol.wordpress.com/2011/11/07/nyamuragira-volcano-erupts-in-the-congo/
Red Alert For Two Chilean Volcanoes - Nov. 1st Chilean authorities keep the red alert in the south of the country due to eruptive activity at the Hudson volcano and the Puyehue Cordon Caulle volcanic complex. Several flights have been canceled during the past week because of the ash plume coming from the Puyehue Cordon Caulle volcanic complex. Jaime Valdenegro, director of the National Emergency Office in Los Rios' region, confirmed an increase in the precipitation of particulate material from the complex, although the massif, about 2, 240 meters high, has registered a minor level of eruption. The Puyehue-Cordon Caulle is located in the Andes, about 900 kilometers south of Santiago. It previously erupted in 1960 after the mega-quake of 9.5 degrees in Valdivia city, considered the greatest in the history of mankind. There are around 3, 000 volcanoes in the Chilean Andes. Eighty of them are active, of which, according to experts, half could erupt in the near future. Among the most explosive are the Puyehue and the Hudson also the Chillan, Antuco, Villarrica, Llaima and Osorno, among others. Chile contains 15 percent of all the active volcanoes in the world. http://www.plenglish.com/index.php?option=com_content&task=view&id=445807&Itemid=1
Oct. 17th Kamchatka's Shiveluch volcano shaken in violent eruption Reports speak of a violent volcanic eruption of Mount Shiveluch on Russia's Far Eastern Kamchatka Peninsula. Smoke and ash from the volcano have climbed to 10 kilometres, sparking no-fly warnings for the surrounding area. Snow around the crater is rapidly melting, creating mudslides. Shiveluch supports a caldera of 1.5 kilometres in diameter. Its current activity period started in 1980.
Volcanic Eruptions at El Hierro Continue as Sea Stain Grows Since
the eruption was confirmed one week ago, the activity has remained submarine,
producing an impressive discoloration of the ocean as volcanic gases and
tephra are released from underwater vents. The sea stain has grown to almost
half the size of the island itself, according to the latest satellite photos.
The green stain is visible on the surface of the sea and in addition to
the stains, officials at Spain's Instituto Geografico Nacional (IGN) report
a strong smell of sulfur and the presence of dead fish floating on the surface.
Scientists said the fish were likely killed by gas escaping from the subsea
volcano. IGN confirms that the large stains come from two fissures on the
sea bed, approximately 2,000 - 3,000 feet below the surface. The fissures
are located less than 2.3 miles and 1.7 miles from the town of La Restinga.
While they remain cautious, the hope is that these eruptions have eased
some of the pressure and potential for eruptive activity occurring near
the island. Full
article.
Sept. 22nd: Indonesia's volcanic tilt continues: Mud volcano alert raised on news of eruption Authorities in East Java have raised the alert level for the mudflow spewing from an underground volcano in Sidoarjo after nearby dikes nearly failed. The mudflow has destroyed hundreds of homes, swamped 720 hectares of land and displaced more than 11,000 people since it began erupting in late May 2006. Indonesia now has 29 volcanoes on alert status, not including the mud volcano. The number is up from 22 just 3 weeks ago. The latest volcano alerts come from Lewotobi Laki-Laki which was given an alert status Level 2. The volcano last erupted in 2003.
Scientists watching new lava flow headed toward Royal Gardens - September 22nd HAWAII - A new lava flow is advancing down the east slope of Puu Oo crater and may pose a threat to the Royal Gardens subdivision if it continues, the Hawaiian Volcano Observatory said. Lava began overflowing the west rim of Puu Oo crater early Tuesday feeding a new lava flow moving down slope on the crater's west side. Two lava lakes are active in Puu Oo, one on the west and the other on the east side of the crater.
Sept. 18th - Alaska - Scientists Concerned By Continued Eruptions
At Alaskan Volcano - The two-month long, low-level eruptions occurring
at a volcano in Alaska's Aleutian Islands have volcanologists worried that
there could be a larger eruption forthcoming, Yereth Rosen of Reuters reported
on Friday. The volcano causing concern is Cleveland Volcano (also known
as Mount Cleveland), a 5,676-foot peak located less about 940 miles
southwest of Anchorage. "The big thing we're concerned about is an
explosive eruption," Steve McNutt of the University of Alaska Fairbanks,
a coordinating scientist for the observatory, told Rosen. Such an eruption,
the Reuters reporter says, could come with "little warning." Satellite
imagery has reportedly shown a lava dome growing inside the volcano's crater,
and the observatory has reports that Mount Cleveland continues to generate
heat. To date, there have been no signs of ash clouds, Rosen said, but those,
too, could come with little warning. McNutt told Reuters that they are concerned
that the dome could completely seal off the crater vent, thus causing pressure
to build until it is released suddenly and violently. Alternatively, the
dome could topple, which would trigger "molten flow down the mountain
that releases gas and ash into the atmosphere while lava and rocks tumble,"
Rosen said. Cleveland Volcano rests underneath a flight path between North
America and Asia that is said to be utilized by several major airlines,
which means that an eruption there could create havoc when it comes to airline
travel. As of 11:53 a.m. Saturday, the Aviation Color Code at the
volcano was Orange.
New eruption of Mount Etna, Sicily, Italy (08/09/2011) - 09.09.2011 On the morning of 8 September 2011, the New Southeast Crater of Etna has produced its 13th paroxysmal eruptive episode of the year 2011. During this paroxysm, brief explosive events occurred also from various spots on the northern flank of the New Southeast Crater cone.
September 6, 2011 - Seismic activity increases at Iceland volcano - REYKJAVIK, Iceland (AP) - A surge of small earthquakes has been reported around Iceland's Katla volcano, but scientists said Tuesday there is no immediate concern that the increased seismic activity will trigger a dangerous eruption. Although earthquakes around Katla are common, an increase in cluster earthquakes is not. "It's one of the most feared volcanos, so we're closely monitoring it," said Pall Einarsson of the University of Iceland. "That said, it's normal for earthquakes to be detected around Katla. What's a bit unusual is that we're seeing swarms of small earthquakes, some occurring every 10 minutes or so." Iceland sits on a large volcanic hot spot in the Atlantic's mid-oceanic ridge. Eruptions, common throughout Iceland's history, are often triggered by seismic activity when the Earth's plates move and when magma from deep underground pushes its way to the surface. Katla, which threatens disastrous flooding if its ice cap melts, typically awakens every 80 years or so, and last erupted in 1918. Activity around Katla started to increase around July but has since grown even stronger. The strongest earthquake detected so far has been a 3.0 magnitude. There also was flooding that wiped out a bridge in July.
Increased activity at 22 volcanoes, alert raised - The Jakarta Post, Jakarta | Sat, 09/03/2011
The government has requested that local administrations remain on the alert for severe risks of volcanic eruptions, as the number of volcanoes showing abnormal activity continued to raise. As of Friday, activity in 22 volcanoes was categorized as above normal, with six at alert level three and 16 at level two. Volcano status ranges from level one, which is normal, to four, which is the highest alert. The Volcanology and Geophysical Disaster Mitigation Center (PVMBG) raised the status of Papandayan, one of the major tourist destinations in Garut, West Java, to alert level three on Friday. "There were 48 shallow volcanic earthquakes detected, with one deep volcanic earthquake and a white cloud emitted as high as 20 meters on Thursday," National Disaster Management Agency (BNPB) spokesman Sutopo Purwo Nugroho said. On Thursday, the government elevated the status of three volcanoes: Tombora, Lewatobi Perempuan and Anak Rakana in Nusa Tenggara. Tombora, in Bima Regency, experienced 14 shallow volcanic earthquakes. Tambora erupted in 1815, killing about 71,000. Activity at Lewotobi Perempuan in Flores increased as well, experiencing 24 earthquakes on Thursday. There were only five the day before. Lewotobi last erupted in 1935.
Katla showing more signs of eruption - 2 Sep 11 Following an intense week of earthquakes and tremors, experts believe magma is slowly filling inside Iceland's massive Katla volcano, giving rise to fears the volcano could soon erupt, producing an ash plume that would continue for for weeks, if not months. It is believed that Katla with a magma chamber about 10 times the size of neighbouring Eyjafjallajokull has the potential to be much stronger and disruptive than the last two Icelandic volcanic eruptions that caused chaos across Europe's air space.
August 28th: Small earthquake swarm detected at Iceland's Katla volcano - A small earthquake swarm has been detected under the M?rdalsjökull glacier where Katla sits. The caldera is 10 km (6 mi) in diameter and is covered with more than 200700 metres (660-2,300 ft) of ice. The strongest quake in the latest burst of new tremors measured a 2.2 on the magnitude scale. A volcano this size produces a large amount of seismic tremors before there is an eruption so it is something only to monitor at this point. Katla is capable of producing a VEI6 eruption, which would be about 100 times more powerful than the 2010 eruption of its little sister Eyjafjallajökull. Katla last erupted in 1918 and many geologists say the two volcanoes usually erupt in concert. So far no increase in harmonic tremor has been detected on the seismometers around Katla volcano. But that might not start at current time, as harmonic tremor is only going to increase when magma starts to move inside the Katla volcano, like did happen in Grímsfjall volcano few weeks ago. Picture of site
August 27th: 10,000 earthquakes in swarm reported on German-Czech border- magma on the move say geologists - The Geophysical Institute, Academy of Sciences of the Czech Republic says it has recorded almost 10,000 earthquakes during the last three days in West Bohemia, a region located close to the Czech Republic's western border with Germany. The earthquake swarm started late on Tuesday and continued through Friday. Commenting on the latest earthquake swarm, the Geophysical Institute, Academy of Sciences of the Czech Republic stated: "The activity started in the evening of 23 August and is almost continuous till now (26 August morning). Almost 10 000 events were recorded in total up to now. Already eight events M>3.0 and 200 M>2.0 occurred. The location of hypocenters directly below the NKC station, so it appears a new patch of the fault plane is being activated." In recent years, scientists have noted an increase in the movement of magma towards the earth's surface in the Cheb Basin, western Czech Republic. They say rising magma could be one of the causes of the earthquake swarms, which regularly occur in the Vogtland, North-West Bohemia, the Fichtelgebirge and the Upper Palatinate. The last earthquake swarm to occur before this week's activity was in 2008.
Saturday 27th August 2011 - Papandayan Volcano, Indonesia Unrest continues at Papandayan volcano in Indonesia. Between 1-24 August 501 shallow volcanic earthquakes were detected. There has been no increase in deformation of the volcano. Visually the volcano shows a weak plume rising 1 km above the crater. There was a decrease in sulphur dioxide emission from the crater from 8 tonnes per day to 6 tonnes between 12-23 August. The alert status at the volcano remains at level 3 out of a maximum 4.
Monday 15th August 2011 - Soputan Volcano, Indonesia - Eruptions occurred at Soputan volcano in Indonesia on 14th August.
Saturday 13th August 2011 - Mt Etna Volcano, Italy A parosysm occurred at SE crater of Mt Etna volcano on 12th August. This was the 10th Paroxysm of the year and occurred 6.5 days after the previous one. This eruption was similar to the previous eruptions with a lava flow toward the Valle del Bove, lava fountains several hundred meters high, and an eruption column that rose about 3 km above the summit.
Saturday 13th August 2011 - Papandayan Volcano, Indonesia Papandayan volcano in Indonesia has been placed on level 3 alert (out of maximum 4) after an increase in unrest. Seismic activity has increased at the volcano with a doubling of volcanic earthquakes in the first 2 weeks of August compared to previous months.
Thursday 11th August 2011 - Karangetang Volcano, Indonesia Karangetang volcano in Indonesia has been raised to level 3 alert after an increase in activity during July and August.
August 5th - The Kamchatka Peninsula, along Russia's Pacific coast, is currently the most volcanically active area in the world: four volcanoes are erupting simultaneously, and a fifth is showing signs of an impending eruption. View
KAMCHATKA: KIZIMEN, SHEVELUCH and KARYMSKY: ORANGE ALERT
BEZYMIANNY and GORELY: YELLOW ALERT
Monday 1st August 2011 - Mt Etna Volcano, Italy
On the evening of July 30, 2011, a paroxysm occurred on the eastern flank of South-East Crater. The event was similar to previous paroxysms, with emission of a lava flow toward the Valle del Bove, lava fountains that reached maximum heights of 450-500 m. An ash cloud drifted east. This eighth episode paroxysm this year lasted less than a day, with an initial phase characterized by weak Strombolian activity for about 10-12 hours, and a lava fountain lasting two to three hours. The paroxysm occurred five days after the previous one on the morning of 25th July. So far this year, the intervals between episodes of paroxysm were 36, 51, 32, 58, 10, 6 and 5.5 days. Check out the webcam for Mt. Etna here.
August 1, 2011 - EARTHQUAKES UNDER EL HIERRO IN THE CANARY ISLANDS: WHAT CAN WE EXPECT?
Over the last few weeks, there has been a lot of buzz in the volcano world (at least in the internet) after some seismicity under El Hierro, one of the many volcanoes that make up the Canary Islands off the coast of Africa. The seismicity, although mostly of low magnitude (< M2), has been of high volume, with over 1,000 of this microquakes occurring since the swarm started in early July. Almost all the seismicity has been confined to depths of 9-16 km below the surface, which in a place like the Canary Islands, is close to/across the boundary of the lower crust and the upper mantle in an oceanic setting such as this. The question on everyone's mind is this: is El Hierro preparing for an eruption and, if not, what is going on underneath the volcano?
Thursday 28th July 2011 - El Hierro Volcano, Canary Islands
An earthquake swarm occurred at El Hierro volcano in July 2011 with 720 earthquakes measured in a week. The earthquakes were measured between magnitude 1-3, and most were at a depth of 5-15 km. The swarm occurred at El Golfo in the northwest of the island at the location of a landslide that created a 100 metre high tsunami about 50,000 years ago. The last eruption at El Hierro volcano occurred in 1793. The island contains 500 volcanic cones.
Eruption advisory for Alaskan volcano - Could disrupt air travel
July 22nd - The Alaska Volcano Observatory has issued an eruption advisory for the 5,676 foot Cleveland Volcano, located in the Aleutian chain about 940 miles southwest of Anchorage. The volcano could erupt at any moment, spewing ash clouds up to 20,000 feet above sea level with little further warning, the observatory said. A major eruption could disrupt international air travel because Cleveland Volcano lies directly below the commercial airline flight path between North America and Asia, said this Reuters article by Yereth Rosen. The volcano last erupted came ten years ago, when it blasted ash more than 5 miles into the sky and spilled lava from the summit crater.
See entire article: http://news.yahoo.com/aleutian-volcano-shows-signs-impending-eruption-023256722.html
July 18, 2011 JAKARTA An Indonesian volcano erupted twice on Monday following its biggest eruption in weeks over the weekend, a government volcanologist said, forcing people to remain in safety shelters. "The two eruptions happened within ten minutes which sent a column of ash and smoke up to 600 meters into the air," government vulcanologist Freddy Korompis said from a monitoring post
Monday 18th July 2011 - Lokon Volcano, Indonesia - Lokon volcano in Sulawesi, Indonesia erupted yesterday sending ash to a height of 3500 m. Ash emissions were visible from Manado. Increasing activity at the volcano forced 5000 people to evacuate. Yesterdays eruption was the largest since the volcano was placed on the highest alert level last week. It last erupted in 1991.
Earthquake swarm in Katla volcano - June 17, 2011 by Jón Frímann -Around 17:10 UTC an earthquake swarm did start in Katla volcano. This earthquake swarm is focused inside the Katla caldera at small point. The one earthquake that I have so far been able to record was an long period earthquake, but that suggests that this earthquake was created by magma movement.
Friday 15th July 2011 - Loki-Fögrufjöll Volcano, Iceland
An eruption has occurred at another volcano in Iceland. A glacial outburst resulted from a subglacial eruption of Loki-Fögrufjöll Volcano on Tuesday night 12th July 2011. The glacial burst occurred from Köldukvíslarjökull, a part of Vatnajökull in southeast Iceland, in a location which was not previously known to have a geothermal area. The flood flowed down the Svedja river into Hágöngulón lagoon and lake Thórisvatn. A flood has never been recorded at this part of the glacier before, although the volcano possibly had subglacial eruptions in 1986 and 1991 from different locations. The water level of Hágöngulón rose 70 centimeters during the flood.
Possible small eruption in Katla volcano, small glacier flood followed it - July 9th - It seems that an small eruption took place in Katla volcano caldera during the night. At the moment it seems to be over. But it is hard to be sure. According to Icelandic news there where three newly formed cauldrons in the M?rdalsjökull glacier. The eruption is unlikely to break the glacier at current time if it remains small. Newest news reports say that cracks have formed in the glacier around the cauldrons.
The bridge over Múlakvísl is gone, it did vanish the flood water early this morning. According to the news the bridge got flooded around 03:00 UTC last night. This means that Road 1 is closed in this area. Currently earthquake activity continues in Katla volcano caldera. But the tremor has been dropping for the past few hours after it topped around 03:00 UTC last night.
There have been 30+ earthquakes in the area and two large cracks were discovered over the caldera by a scientist team flying over the volcano yesterday. There has also been strong harmonic tremors recorded. The Icelandic Met Office haven't yet confirmed an eruption has started, but this is certainly the strongest sign the volcano has given us that she's ready to blow. See Earthquake map, July 10th, Iceland. "This doesn't seem to be the large eruption that people have been waiting for at Katla," said Freysteinn Sigmundsson, a geophysicist at the University of Iceland. Katla, said to be 10 times more powerful than Eyjafjoell, last erupted in 1918, sending a wall of meltwater down the glacier, bearing ice chunks the size of houses, and blanketing southern Iceland in thick ash. According to other experts, Katla is overdue for a powerful blast.
Opposing cycles for Katla and Long Valley Caldera?
Harmonic tremor continue to increase in Katla volcano - July 9th, 00:36 UTC - Jón Frímann - The harmonic levels are getting so strong that they have started to appear on stations around Hekla and on my own geophone, even if it is located almost 60 km away from the source of the harmonic tremor. Currently there is little to suggests that this is slowing down at the moment. The lack of earthquakes tells me that the magma has not yet reached the surface. Some minor earthquakes have been taking place in the past few hours, they do not appear on the automatic earthquake list on Icelandic Met Office web page. Some of them appear on my Hekla webicorder. Currently the harmonic tremor is dropping. But that might not mean anything in the long run. So far everything suggests that an eruption has not yet started in Katla volcano. But given the current status that might not last long as it is. The best thing that can be done is to wait and see what happens. But no fear scaremongering please!
Added: When I just finished writing this blog post an new earthquake just started to appear on my geophone at Hekla volcano. IT is from Katla volcano for sure. It was in the ML1.5 to ML2.5 size range it seems. It was an long period earthquake as they have been so far. I think it is from the main caldera, not Godabunga area.
Jökulhlaup in Myrdalsjökull - Iceland · July 8, 2011 11:23 PM
A jökulhlaup has started in Múlakvísl, the glacial river that comes off Myrdalsjökull, that is the glacier that Katla is under. No eruption at this point though. Lots of small earthquakes in a line across the caldera though. Some have a depth of less than a km, and are, most likely, just the ice shifting, but there is steady activity down to 10-15 km depth, suggesting some magma movement. Police are warning of strong H2S odour on the sands, and possibly lethal concentrations of the gas in low lying areas nearby.
Myrdalsjökull on 8th July 2011 - view picture the big round thing is Katla's caldera - the outlet glacier in the foreground (from mbl.is)
Múlakvísl is the outlet river on the western edge of the sands, few km east of Vík, if Katla erupts it will probably go to very high flood stage, and the sands become impassable. The river is rising, not clear when it will peak at this stage, water conductivity is high, indicative of high concentrations of ionic salts, and geothermal origin. I used to take samples of the river water, for the hydrology group, using a boom off one of our trucks, hanging off the bridge across the river. Checking on salts and solutes. Every time I'd swear the damn sulphide smell got stronger, we had instructions to cut the wire and leave fast if the smell spiked and the river started rising. The last proper jökulhlaup in 1955 took the bridge out.
As usual, Jón Frímann is on it
PS: holy crap! This is a snapshot from the water meter upriver - level jumped 5 meters in minutes, the downriver meter by the bridge jumped 3 meter, then leveled off - probably getting a dam from the bridge floor.
PPS: at 5 am RUV is reporting the bridge across Route 1 at Múlakvísl is overtopped by the flood, and it does not appear to have peaked. Route 1 is closed at M?rdalssandur.
Indonesian volcano erupts - Jakarta (AFP) July 3, 2011 A volcano on Indonesia's Sulawesi island erupted Sunday, spewing ash and smoke 5,000 metres into the air.
Mount Soputan in North Sulawesi province erupted at around 6:03 am (2203 GMT Saturday) but people living in the sparsely populated area have not been evacuated, Iing Kusnadi, a scientist at the volcano's monitoring post told AFP. "The volcano erupted this morning. Besides spewing ash and dust particles, it also spewed hot gas but that's limited to around its crater," he said. "The recommended evacuation zone is set at a six-kilometre radius around the volcano but there's only forest in that range," he added. The nearest village is eight kilometres away on the western side of the volcano, which towers 1,783 metres (5,800 feet) over North Sulawesi province. Soputan, one of Sulawesi's most active volcanoes, last erupted in 2008 with no fatalities recorded.
Indonesia sits on the Pacific "Ring of Fire" where continental plates collide, causing frequent seismic and volcanic activity. The archipelago nation is home to 129 active volcanoes, including 21 on Java.
Earthquake swarm in
Katla volcano - June 17th - View
current map and you can view the map
of the whole country here
With an area of about 227 sq miles (590 sq km), the Myrdalsjokull is the
fourth largest glacier in Iceland. Katla volcano lies beneath the glacier.
The ice in Katla's caldera is hundreds of meters thick.
Just west of Myrdalsjokull lies the much smaller Eyjafjallajokull glacier with 19 sq miles (50 sq km).
Indonesia's Mount Batur's volcanic lake changes color- thousands of fish die - June 20, 2011 - On Sunday, June 19, 2011, the waters of the lake that sits in a volcanioc crater suddenly changed colors to a whitish-blue shade followed by the sudden death of thousands of fish (tilapia) living in the lake. The last eruption of the volcano occurred in the year 2000.
June 14, 2011 - After the excitement surrounding the eruption of Nabro yesterday it seems that activity has died down. The likelihood is that this event is a fissure eruption which had an explosive component at an early stage. Puyehue-Cordón Caulle is still erupting but is less active than when it first erupted. Elsewhere at the Dieng Volcanic Complex the current period of increased activity is continuing with the alert remaining at Level 3 for the second week running. Seismicity and gas emissions (specifically CO2) remain at elevated levels
June 13, 2011 12:1705 UTC : Eritrea volcano Nabro eruption, a volcano that has NO sign of being erupted in recent history. It erupted on June 12th after a series of moderate earthquakes along the Great Rift Valley at a depth of 10 km. The estimated height of the ash cloud is ~13.5km, according to the VAAC. This is an essential piece of information in predicting the current size of the eruption, as the height of the ash cloud often reflects the force behind the eruption. In this case, it would so far be an average-to-large eruption. For comparison; the ashcloud from the Eyjafjallajokull only came up to 9km in April 2010, the more recent Grimsvotn eruption in Iceland forced ash up to 20km in the air, and the 1981 Mt. St Helens eruption's ashcloud reached 25km into the atmosphere.
June 7, 2011 - ICELAND It seems nothing with the Earth is what it seems these days and everything is on a dynamic hair-trigger that could change in an instant. After the eruption of the Grímsfjall volcano abated, it seems Iceland is now shaking again.
6 Jun 11 - The volcanic complex Cordón Caulle erupted on Saturday in southern Chile for the first time in 50 years, causing the evacuation of thousands of people in surrounding areas. A column of steam and ash reached more than ten miles high and then headed for Argentina as an eerie lightning show danced through the ash clouds overnight. A rift more than 6 miles (10 km) long and 3 miles (5 km) across was torn in the earth's crust, officials said Saturday night.
June 3, 2011 MEXICO CITY - The Popocatepetl volcano that towers over Mexico City is rumbling again. The 17,886-foot (5,450-meter) mountain shot a blast of ash about 2 miles (3 kilometers) above its crater at dawn Friday.
Thursday 2nd June 2011 - Dieng Volcano, Indonesia - Gas emissions from Dieng volcano in central Java has forced the evacuation of 1200 residents. On 28th May there was a sudden increase in carbon dioxide emissions at Timbang. On the 29th May there was a felt earthquake at the volcano followed by shallow seismic activity. This corresponded to a phreatic eruption at Timbang crater. Dead birds were found near the crater. People are advised to remain at least 1 km from Timbang crater. The alert status hat the volcano has been raised to level 3 (Siaga) out of a maximum 4.
Taal Volcano - As of the 3rd of June, PHIVOLCS reported that seismic network recorded four (4) volcanic earthquakes during the past 24 hours. Field measurements conducted last 31 May 2011 at the western sector inside the Main Crater Lake showed that the water temperature increased from 32.5 ° C to 32.9°C, and the pH value became more acidic decreasing from 2.72 to 2.60. Bubbling activity was observed at the middle portion of the Main Crater Lake. As of the 2nd of June, PHIVOLCS reported that Taal Volcano's seismic network recorded thirteen (13) volcanic earthquakes during the past 24 hours. Two of these events were felt at Intensity II by residents of Calauit located at the eastern sector of the volcano. The events were reportedly accompanied with rumbling sounds.
Taal Volcano continues intensified seismic activity - May 31, 2011 - a total of 31 volcanic earthquakes were recorded during the past 24 hours in Taal Volcano. Phivolcs yesterday reported a "remarkable increase in the seismic activity" of the volcano, recording a total of 151 events from Sunday to early morning of Monday. The volcanic quakes reported on Monday and today were "accompanied by rumbling sounds.
Taal volcano shaken by 115 earthquakes in 24 hours: This is the highest number of tremors recorded in the area since the Philippine Institute of Volcanology and Seismology placed the restive volcano under Alert Level 2 last April. The volcano's increased seismic activities and sustained high emission rate of carbon dioxide being released in its main crater lake meant that magma has been intruding towards the surface. "Its already on Alert level 2, meaning there is a confirmed rising of magma from below, so these tremors are part of the episodic rising of magma." "Taal volcano has experienced earthquake swarms long before, ever since the 90's, but it has not erupted." Sabit also added that "The volcano's activity varies because previously the quakes were scattered in several areas but the recent ones were clustered in one area." Asked whether the recent fish kill incident in Sampaloc Lake was connected to the quakes, Sabit said that "the fish kill occurred in one area, if volcanic activity caused it, it should have affected the area near the volcano first. San Pablo City, Laguna is quite far from the Taal volcano." Sabit said that the fish were probably killed because of the sudden change in temperature.
Taal volcano: hundreds of thousands of fish found dead in lake surrounding volcano: Volcano heats Taal Lake. Nearly seven hundred tons of milkfish were found floating in Taal Lake in the northern Philippines! That's 1,543,235 lbs. and 700,000 kg of dead fish!
May 26th: Philippine's Bulusan Volano shaken by 31 quakes in 24 hours. One day after 38 volcanic quakes were recorded at Mayon Volcano in Albay, it was the turn of another volcano in the Bicol Region to show heightened activity. The Philippine Institute of Volcanology and Seismology said Thursday 31 volcanic quakes were recorded at Bulusan Volcanon in Sorsogon in the last 24 hours. "Bulusan Volcano's seismic network recorded 31 volcanic earthquakes during the past 24 hours. Steaming activity was not observed due to thick clouds covering the summit," Phivolcs said in its Thursday update. The Bicol Region is one of the areas presently threatened by Typhoon Chedeng (Songda). Much of the region was under Storm Signal 2 as of Thursday morning. Phivolcs said Bulusan's status remains at Alert Level 1, meaning the source of activity is hydrothermal and shallow. It maintained entry to the 4-km radius Permanent Danger Zone (PDZ) is strictly prohibited, since the area is at risk to sudden steam and ash explosions. Due to the prevailing wind direction, residents in the northwest and southwest sectors of the volcano are reminded to take precautions against ashfalls. Civil aviation authorities were urged to warn pilots to avoid flying close to the volcano's summit as ejected ash and volcanic fragments from sudden explosions may be hazardous to aircraft. -GMA News
OROUMIEH LAKE, Iran - largest lake turning to salt. Oroumieh Lake, the third largest saltwater lake on earth has shrunken by 60 percent and could disappear entirely in just a few years.
May 26th: Update on volcanic activity in Grímsvötn Plume is no longer detected on radar at 70 km distance from the eruption site although minor steam explosions are observed in the crater. Ashfall occurs only in the vicinity of the eruption site. Visual observations of Grímsvötn show that little ice has melted during the eruption, meaning that an outburst flood (jökulhlaup) is not to be expected. Long-term conductivity measurements of Gígjukvísl suggest that meltwater is draining freely from Grímsvötn following a jökulhlaup from the lake last autumn. There are ongoing gas-explosions in a crater at the southern rim of the volcano, according to an overflight yesterday at 19 hrs. Overall assessment: Very little changes since yesterday. Explosions continue, only affecting the area around the crater.
May 24, 2011 - The Iceland Eruption May be Close to an End - Scientists say that the Grímsvötn Eruption is now considerably smaller than yesterday. According to RÚV volcanologist Ármann Höskuldsson says that the eruption is dying out. Iceland Review
May 22, 2011 Iceland Largest volcanic eruption in Grímsvötn in 100 Years - The current volcanic eruption in Grímsvötn on Vatnajökull glacier is the largest in that volcano 100 years and larger than the one in Eyjafjallajökull last year. It is similar to the eruption of 1873, according to geophysicist Magnús Tumi Gudmundsson. A large flood is not expected. This morning the ash cloud was 15 to 18 kilometers high which means that the volcanic eruption is ten times more powerful than the last eruption in Grímsvötn in 2004, Gudmundsson told ruv.is. However, it is not unique. Grímsvötn goes through phases where it erupts often in a period of 60-80 years, then there are quieter periods of equal length. In these quieter phases there are small eruptions such as the ones in 1998 and 2004 and then the third and fourth eruption are larger in scale, like in 1619 and in 1873, which is similar in character as the one we're experiencing now. It is much larger with much more magma flow and much more emission of ash than what we witnessed in the volcanic eruption in Eyjafjallajökull last year. The ash scatters widely and the ash cloud stretches over a large part of the country. Iceland Review A veteran pilot who has flown over 23 volcanic eruptions here has just said he has never seen such a big eruption.
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
May 18, 2011 - Frequency of Tremors on the Rise in Guerrero - So far in the month of May, 60 tremors have been registered in Guerrero, mostly in the Richter range of 3 or 4. Monday afternoon a tremor of 4.3 was felt and an earlier one of 5.5 was registered on May 5 with the same epicenter, in the municipality of Ometepec, in the Costa Chica, to the east and south of Acapulco. More than one-third of the tremors taking place in this month in Guerrero have had their origin in the Costa Chica. Real Acapulco News
Five tremor epicenters have occurred within the municipality of Acapulco since May 1, all of them between 3 and 4 on the Richter scale. The tremors felt in Guerrero in the first two weeks of May is double the number registered for the same period last year.
May 5th: Ecuador: Everyone is still watching Tungurahua, where a new period of intense explosive activity has begun. The current eruption at Tungurahua is the largest since 1999 and some of the towns near the volcano have seen over 15.5 mm of ash fall since the activity began - totaling an estimated 1.6-3 million m3 of tephra, according to the Instituto Geofísico.
Indonesia: A volcano that hasn't been in the news lately in Indonesia appears to be showing signs of restlessness, namely Gamkonora. Most of the previous eruptions over the last few hundred years have been VEI 1-2 (small), but the 1673 eruption is estimated to be a VEI 5 (and produced a tsunami), so the potential is there. The latest report from Gamkonora mentions white plumes coming from the summit and a sulfurous odor, prompting an elevation of the alert status to 2. Indonesia is still recovering from its last major eruption at Merapi, with the government taking charge to move people displaced by the eruption to safer, permanent homes.
Kamchatka: As
always, the far eastern Russian Peninsula is in the news for volcanic activity. Shiveluch and
Kizimen (see below) have both been producing moderate ash plumes that
have reached 6 km / ~20,000 feet, while Karymsky has been erupting
slightly smaller plumes (for Kamchatka)
April 27, 2011, 11:00 AM - Tungurahua in Ecuador has largest eruption in the past decade
The seemingly constantly restless Tungurahua had a significant explosive eruption, prompting evacuations of schools and villages near the volcano. Tungurahua produced a 7 km / ~23,000 foot ash plume, which is a bit surprising considering that last report from Instituto Geofisico in Ecuador from January 2011 reported "activity at Tungurahua continued to decrease and ash was absent from plumes." This eruption clearly shows that the volcano has roared back to a period of activity - you can read some of the details on the IG update for the current eruption (Spanish), including reports of 6 explosions in the last day and severe ground shaking in the town of Banos near the volcano. Hugo Yepes, a geologist from the IG, was quoted as saying (Spanish) this eruption was one of the largest at the volcano in the past 11 years and that the IG expects that this eruption might gone on for "several days". The Ecuadoran government placed the volcano on Orange Alert status, meaning mandatory evacuations for a number of villages near Tungurahua. Some air traffic in and out of Quito has also been effected by the eruption. There are a number of webcams trained on Tungurahua, so you can try to check out the activity through the clouds yourself.
The Kilauea Kamoamoa Fissure Eruption - Kamoamoa, which cracked open Saturday, is continuing to spew out loads of lava and gases. Meanwhile, visitors flock to Hawaii Volcanoes National Park hoping to catch a glimpse of the 2,000-degree Fahrenheit (1,093-degree Celsius) glowing, red-orange lava that is shooting 65 feet (20 meters) high. But visitors are being kept far away from the isolated, remote east zone rift where the eruption is taking place.
April 24, 2011 KAMCHATKA The Shiveluch volcano has spewed a new plume of ash 7.5 km above the Russian Kamchatka Peninsula. The ash cloud sprawled 143 km to the northwest. The authorities announced the orange alert level warning aircrafts about volcanic dust and gases in the air. At present, there is no risk to human health. Shiveluch, is one of Kamchatka's largest volcanoes. It rises more than 3.200 meters above sea level.
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
Thursday 21st April 2011 - Taal Volcano, Philippines
Taal volcano in the Philippines has been placed on level 2 alert due to an intrusion of Magma towards the surface. The temperature of the main crater lake has increased to 31.5 ded C. There has been a small inflation of the volcano. High levels of carbon dioxide have been released in the main crater and seismic activity is elevated.
More Evacuated near Taal Volcano in Philippines - Lake temps rise to 88.7°F
20 Apr 11 - More people have been evacuated from towns and villages near Taal volcano, where seismologists have recorded 13 volcanic earthquakes in the past 24 hours. Intensity 3 and Intensity 1 volcanic earthquakes were felt in two villages near Taal Volcano, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported. Phivolcs said that at least one of the tremors was accompanied by rumbling sounds, and that temperatures in the main crater lake had increased from 30.5°C (86.9°F) to 31.5°C (88.7°F). The edifice has experienced slight inflation since the last measurements in February, and now stands at Alert Level 2, meaning that "magma has been intruding towards the surface." Meanwhile, Phivolcs recorded two volcanic earthquakes in the last 24 hours at Bulusan Volcano in Sorsogon on Luzon Island, along with moderate steaming on the northwest vent and very weak steaming at the southeast vent. Bulusan's status remains at Alert Level 1.
Etna volcano (Italy):
new paroxysm on 10 April 2011 - On 10 April 2011, the activity which
had started with weak strombolian activity from the collapse carter on the
east foot of the SE crater evolved inot a new, violent and spectacular eruption
(paroxysm), including lava fountains, 3 km long lava flows and a tall column
of ash. This was the 3rd such event in 2011.
Christchurch Animated Quake Map - Beginning Sept. 4, 2010 - 5063 quakes
Understanding Plate Boundries and Volcanoes in the New Zealand area - Is Christchurch headed for a volcanic eruption? Sits beside two "extinct" volcanoes. Banks Peninsula, just south of Christchurch, consists of two overlapping extinct volcanoes, the Lyttelton Volcano and the Akaroa Volcano. ...read more
Philippines' Mount Bulusan volcano explodes evacuations ordered - February 21, 2011 MANILA, Philippines - Hundreds of villagers fled to safety Monday after a restive volcano belched ash and smoke into the sky after a monthlong lull, officials said. Despite Mount Bulusan's ash explosion, its 13th since November, there were no signs of an imminent eruption involving magma pushing out of the cone, said government chief volcanologist Renato Solidum.
Is a thermal anomaly developing in Kuril's volcanic archipelago? - February 23, 2011 KURIL ARCHIPELAGO Just east of Russia and north of Japan lies a long series of island volcanoes called the Kuril chain. Over 50 volcanoes form this archipelago, which stretches for well over 1300 km (800 miles) in the western Pacific ocean. At the southern end is the bizarrely-shaped rectangle of Ostrov Shikotan, and in the winter icy waters swirl and flow around the snow-covered terrain.
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 Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH
August 5th:
Activity Summary for past 24 hours: In the east rift zone: Pu`u `O`o crater walls continued to collapse; lava was trickling back onto the collapsed crater floor; lava continued to issue from west flank vents and pond near the vents. At the summit, the lava lake surface continued to recede. Seismicity was low. Gas emissions remained elevated from summit and rift zone vents.
Past 24 hours at the middle east rift zone vents: The walls of Pu`u `O`o Crater continued to collapse yesterday including a block immediately to the left of the webcam which dropped in overnight. A trickle of lava returned to the very deepest part of the collapsed crater floor yesterday morning and was visible in the webcam overnight. During yesterday's overflight, the depth of the collapse was measured at about 75 m (245 ft) below the east rim. The flows that gushed out of the west flank vents on August 3rd remained active but with the outer limits of activity retreating back toward the sources; in other words, lower effusion rates weren't allowing the active lava to travel as far from the vents before solidifying. The flows remained entirely within Hawai`i Volcanoes National Park and pose no direct hazard to any developed areas.
The GPS network around Pu`u `O`o Cone recorded slow contraction across the cone overnight. The tiltmeter on the north flank of Pu`u `O`o Cone recorded continued deflation. Seismic tremor levels were low. The most recent (preliminary) sulfur dioxide emission rate measurement was 3,100 tonnes/day on August 4, 2011, from all east rift zone sources.
Background: The eruption of Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and has continued with few interruptions through Pu`u `O`o Crater or vents within a few kilometers to the east or west. Since late March, lava has been filling the collapsed crater within Pu`u `O`o Cone, first building a perched lava lake that, in July, evolved into a shield with the lake at its top as a result of uplift of the crater floor and lake. In early August, the crater floor again collapsed as lava burst from vents on the west flank of Pu`u `O`o cone.
Past 24 hours at Kilauea summit: The lava lake level continued to drop with a few fill-and-drain cycles superimposed. The circulation pattern remained generally from the southeast to the northwest spattering sink until about 6 pm when it reversed and lava upwelled along the northwest edge and, presumably, drained into a sink out of view along the southeast edge. The lava level is well below the inner ledge which was recently measured to be about 75 m (245 ft) below the Halema`uma`u Crater floor.
The summit tiltmeter network continued to record deflation at a rate of about 4 microradians per day. The summit GPS network recorded about 1 cm/d of contraction since August 3rd. Seismic tremor levels were high between 8:40 pm last night and 2:20 am this morning, apparently associated with a minor drop in lava lake level. Seven earthquakes were strong enough to be located within Kilauea volcano - three within the upper east rift zone and four on south flank faults.
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.
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. Kilauea Crater - explosive events are capable of ejecting rocks and lava several hundred meters (yards) from the Halema`uma`u vent; 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 vents and flow field - The only lava
erupting from Kilauea volcano's east rift zone is within Pu`u `O`o Crater
within Hawai`i Volcanoes National Park. Access and viewing information can
be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. Access via
Kahauale`a Natural Area Reserve is closed by the state of Hawai`i Department
of Land and Natural Resources. Kilauea Crater - Hawai`i Volcanoes National
Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.
Maps, photos, Webcam views, and other information about Kilauea Volcano are available at http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php. A daily update summary is available by phone at (808) 967-8862.
A map with details of earthquakes located within the past two weeks can be found at http://tux.wr.usgs.gov/
A definition of alert levels can be found at http://volcanoes.usgs.gov/activity/alertsystem/index.php
Definitions of terms used 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
August 5th:
During the month of July 2011, 54 earthquakes were located in the Yellowstone National Park region. The largest was a magnitude 2.1 event on July 8 at 7:33 AM MDT, located about 9 miles west southwest of Old Faithful, YNP. No swarms were recorded in July.
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
