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Bizarro Earth

Indonesia: Anak Krakatau Raised To Highest Alert Status- Quakes Are Now Continuous, Warn Officials


Viva News
Sun, 02 Oct 2011 18:27 UTC
Anak Krakatau
© volcano.si.eduGunung Anak Krakatau
Indonesian officials have raised the status of one of its most dangerous volcanoes, Anak Krakatau, to a "standby" or level IV- the highest level.

The Center for Volcanology and Geological Hazard Mitigation (PVMBG), Surono said this is a rise in status that was set on Friday, September 30, 2011 evening at 24.00. The reason for the elevated status is because of the high-intensity level of earthquakes.

Today, for example. "On October 2, 2011, at 00.00 until 12.00, there are 2745 recorded seismic events," said Surono, when he was contacted by VIVAnews.com, Sunday, October 2, 2011. Earthquakes under Mount Anak Krakatau, Surono added, were even felt all along the island of Anak Krakatau.

"The swarm of tremors are continuous and although small, 2 on the Richter scale, they are cause for concern because they are felt constantly," he added. He explained, almost since 2007, Krakatau has been stirred by unrest. "In a moment, it stopped, and erupted in 2009. I think this mountain is always in danger of erupting," he added. - Viva News (translated)
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Bizarro Earth

Indonesia: Infamous Mount Tambora is rumbling again


Hawaii247.com
Thu, 29 Sep 2011 10:14 UTC
Skies darkened, temperatures plunged, crops failed, and disease and famine ensued. These and other strange phenomena afflicted people around the world in 1816, known as "The Year without a Summer." We now know that the great eruption of Mount Tambora, in Indonesia, the previous year had triggered these changes. With Mount Tambora rumbling again this month, are we about to experience another global catastrophe?

Image
© Jialiang Gao /peace-on-earth.orgMount Tambora caldera
Before we answer that, let's examine the 1815 eruption and its remarkable effects. Mount Tambora became restless in 1812 and in April 1815 produced a series of major explosions that peaked on April 10-11. Large ash plumes rose to great heights, and pyroclastic flows swept down the flanks for several days, wiping out entire villages. When the pyroclastic flows reached the sea, they triggered tsunamis that further devastated the surrounding areas.

The eruption was massive, rated as a 7 on the Volcanic Explosivity Scale of 0-8. By comparison, the volume of magma it erupted was about 40 times greater than that of the 1980 eruption of Mount St. Helens and 10 times greater than that of the 1991 eruption of Pinatubo.
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Bizarro Earth

Eruption At Sakurajima Volcano, Japan September 27

Mark Dunphy
Irish Weather Online
Fri, 30 Sep 2011 10:11 UTC
Sakurajima (桜島?) is an active composite volcano (stratovolcano) and a former island (now connected to the mainland) of the same name in Kagoshima Prefecture in Kyūshū, Japan. The lava flows of the 1914 eruption caused the former island to be connected with the Osumi Peninsula.

The volcanic activity still continues, dropping large amounts of volcanic ash on the surroundings. Earlier eruptions built the white sands highlands in the region.

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Bizarro Earth

Italy: Mount Etna Erupts For Fifteenth Time This Year


Irish Weather Online
Fri, 30 Sep 2011 10:07 UTC
The Mount Etna volcano in Sicily, Italy, erupted for the fifteenth time this year late on Wednesday.

Throughout 2011, activity at Sicily's Mount Etna has been characterised by paroxysms: short, violent bursts of activity. Each event has included volcanic tremors, ash emissions, and lava flows centered around the New Southeast Crater, just below the summit.

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Bizarro Earth

Ethiopia: Eruption Continues At Nabro Volcano In Eritrea

Mark Dunphy
Irish Weather Online
Fri, 30 Sep 2011 10:01 UTC
Satellite imagery suggests that the eruption of Nabro Volcano in northeast Africa, which began in June 2011, is continuing.

The volcano is located on the edge of the Danakil Desert, a remote and sparsely populated area on the border between Eritrea and Ethiopia, and few eyewitness accounts of the eruption are available.

Orbiting instruments such as the Advanced Land Imager (ALI) aboard Earth Observing-1 (EO-1), which acquired these images, may be the only reliable way to monitor Nabro.

Image
© NASA / Robert Simmon
The images show the volcano in false-color (top) and natural-color (lower) on September 28, 2011. Heat from vents in Nabro's central crater is visible as a red glow in the false-color image. Another hotspot about 1,300 meters (4,600 feet) south of the vents reveals an active lava flow. A pale halo surrounding the vents indicates the presence of a tenuous volcanic plume. South of Nabro's crater, the dark, nearly black areas are coated with ash so thick it completely covers the sparse vegetation. On either side of this region is a thinner layer of ash with some bright green vegetation (exaggerated in false-color) poking through.
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Bizarro Earth

Increasing Indications of a Potential Eruption at El Hierro?


Wired.com
Wed, 28 Sep 2011 08:13 UTC
El Hierro
© Wired.comPotentially young pahoehoe lava flows at El Hierro in the Canary Island.
We've been closely watching the earthquake swarm at the Canary Island's El Hierro since the middle of the summer and it looks like there has been a dramatic increase in the number and intensity of the seismicity at the volcano. Since mid-July, the small island, which is the top of a shield volcano built by the Canary Hotspot, has registered over 8,000 earthquakes - check out the excellent video of the changing depth and location of seismicity put together by Eruptions reader Lurking (or is it GeoLurking now?) Until recently, the earthquakes have not been noticeable to the people living on El Hierro, but since Monday, multiple ~M3-4 earthquakes have occurred, with 30 earthquakes alone on Monday*.

Interestingly, if you look at the distribution of the earthquakes (see below), the earthquakes over the last few days are deeper than those 4 days ago or older. Many are centered 14-16 km below the surface of the volcano, putting them into the upper mantle, the likely source of the magma in the Canary Hotspot plume. The increasing seismicity and intensity might suggest that an eruption is in the cards, but you would really expect the earthquakes should be getting shallower as magma nears the surface and right now, it doesn't appear to be the case. Maria Jose Blanco, director of the National Geographic Institute on the Canaries puts the chances of an eruption in the near future at ~10%, although carbon dioxide emissions are steadily rising (spanish), another clue on new magma degassing under the volcano.

Comment: For additional data see Canary Islands Government Raises El Hierro Volcanic Risk Level.

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Bizarro Earth

Canary Islands Government Raises El Hierro Volcanic Risk Level

Mark Dunphy
Irish Weather Online
Mon, 26 Sep 2011 11:19 UTC
The Canary Islands Government has raised the alert level for the El Hierro volcano in the Canary Islands (Spain) to 'Yellow', the highest alert status since an unprecedented earthquake swarm commenced in mid-July.

Spanish seismologists, accompanied by the President of the Cabildo de El Hierro and the Minister of Security and Emergency Area, held a press conference on Sunday to reassure the 10,000 residents of the smallest of the Canary Islands that the raising of the alert level does not indicate that an eruption is imminent. They indicated, however, that the number of volcanic earthquakes detected beneath El Hierro continues to increase.

Image
© Google mapsEl Hierro (circled) in The Canary Islands.
Hierro, a shield volcano, has had a single historic eruption from the Volcan de Lomo Negro vent in 1793. The eruption lasted approximately one month and produced lava flows.

The Canary Islands Government commenced an in-depth geological survey of El Hierro earlier this month in an effort to determine the source of an earthquake swarm.
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Bizarro Earth

Rumblings within Indonesia's Mount Tambora volcano: could eruption bring year without summer?

Steve Tracton
Washington Post / Associated Press
Fri, 23 Sep 2011 11:20 UTC
Image
© Smithsonian, NASA Landsat7 imageMt. Tambora
The eruption of the Mt. Tambora volcano in April 1815 was the largest and most deadly volcanic eruption in recorded history. Its sunlight dimming particles caused a major cooling in the global climate that led to 1816's "Year Without a Summer".

Experts are now saying that Mount Tambora is ready to erupt again as a sequence of earthquakes has been shaking the island at increasing frequency since April. Columns of ash are already venting as high as 4,600 feet. (Note: Tambora was about four times more powerful than Indonesia's much better-known Krakatoa blast of 1883 - history's second-deadliest).

While it appears that Tambora is on the verge of erupting, no one knows with confidence how big it will be. Given the potential consequences, Indonesian authorities have raised the volcano alert to its second-highest level. Active disaster preparedness is underway with evacuation routes mapped and armed forces pre- deployed if the worst occurs (alert status reaching the highest level).
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Attention

Indonesia: Threat Level from 'Mud Volcano' Increases

Arientha Primanita & Antara
Jakarta Globe
Thu, 22 Sep 2011 15:45 UTC
Sidoarjo Mudflow
Sidoarjo Mudflow in 2007
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.

"The situation is alarming," said Achmad Khusaeri, a spokesman for the Sidoarjo Mudflow Mitigation Agency (BPLS), adding that the underground volcano had begun to erupt again after lying virtually dormant for years.
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Bizarro Earth

US: Observatory spots lava erupting within summit crater of volcano on Alaska's remote Aleutians


Washington Post / Associated Press
Wed, 21 Sep 2011 11:44 UTC
Image
© USGS
A volcano in Alaska's remote Aleutian Islands has begun oozing lava, a signal that the mountain could explode and send up an ash cloud that could threaten aircraft.

Satellite images show lava is building in the crater at the summit of 5,675-foot Cleveland Mountain on an uninhabited island about 940 miles southwest of Anchorage, according to the Alaska Volcano Observatory.

"It's forming a dome-shaped accumulation in the crater," said Chris Waythomas of the U.S. Geological Survey, the observatory's acting scientist in charge. "We call these things 'lava domes.' It looks like a muffin top."

Lava domes form a lid on a volcano's "plumbing," including the chamber holding the magma. When they grow big enough, lava domes become unstable and will sometimes collapse, decompressing the magma chamber and leading to an explosion, Waythomas said.
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