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Bizarro Earth

Increasing Indications of a Potential Eruption at El Hierro?

El Hierro
© Wired.com
Potentially 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.


Bizarro Earth

Canary Islands Government Raises El Hierro Volcanic Risk Level

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 maps
El 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.

Bizarro Earth

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

Image
© Smithsonian, NASA Landsat7 image
Mt. 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).

Attention

Indonesia: Threat Level from 'Mud Volcano' Increases

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.

Bizarro Earth

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

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.

Phoenix

Chile: Low Level Activity Continues At Chilean Volcano

puyehue Chili
© Unknown
As the eruption of Puyehue Cordón Caulle wanes, life is returning to normal in nearby communities.

The first domestic aircraft landed at Bariloche, Argentina, in more than three months commenced on Saturday (17 September) while residents began the process of returning to their homes close to the volcano.

Bariloche is an Andean town about 60 kilometers southeast of the eruption center. At the time, winds blew the ash plume from Puyehue Cordón Caulle towards the northwest, away from the town. An airport spokesperson expects future traffic to be dependent on the weather.

The above natural-color satellite image shows Puyehue Cordón Caulle and the surrounding area at roughly local noon on September 17. A pale plume of volcanic gas and ash streams to the northwest from the active vent. The September 15 status report from the Chilean National Service of Geology and Mining (SERNAGEOMIN) stated that the eruption continued at a low level.

NASA image courtesy Jeff Schmaltz MODIS Rapid Response Team, NASA-GSFC. Instrument: Terra - MODIS

Bizarro Earth

Indonesia: Farmers Flee as World's Deadliest Volcano Rumbles

Image
© AP Photo/KOMPAS Images, Iwan Setiyawan
In this Oct. 19, 2010 aerial photo, Mount Tambora's 10 kilometers (more than 7 miles) wide and 1 kilometer (half a mile) deep volcanic crater, created by the April 1815 eruption, is shown. Bold farmers routinely ignore orders to evacuate the slopes of live volcanos in Indonesia, but those on Tambora took no chances when history's deadliest mountain rumbled ominously this month, Sept., 2011.
Bold farmers in Indonesia routinely ignore orders to evacuate the slopes of live volcanoes, but those living on Tambora took no chances when history's deadliest mountain rumbled ominously this month.

Villagers like Hasanuddin Sanusi have heard since they were young how the mountain they call home once blew apart in the largest eruption ever recorded - an 1815 event widely forgotten outside their region - killing 90,000 people and blackening skies on the other side of the globe.

So, the 45-year-old farmer didn't wait to hear what experts had to say when Mount Tambora started being rocked by a steady stream of quakes. He grabbed his wife and four young children, packed his belongings and raced down its quivering slopes.

"It was like a horror story, growing up," said Hasanuddin, who joined hundreds of others in refusing to return to their mountainside villages for several days despite assurances they were safe. A dragon sleeping inside the crater, that's what we thought. If we made him angry - were disrespectful to nature, say - he'd wake up spitting flames, destroying all of mankind."

Bomb

History's deadliest volcano comes back to life in Indonesia, sparking panic among villagers

Indonesia Volcano
© The Washington Post
Bold farmers in Indonesia routinely ignore orders to evacuate the slopes of live volcanoes, but those living on Tambora took no chances when history's deadliest mountain rumbled ominously this month.

Villagers like Hasanuddin Sanusi have heard since they were young how the mountain they call home once blew apart in the largest eruption ever recorded - an 1815 event widely forgotten outside their region - killing 90,000 people and blackening skies on the other side of the globe.

So, the 45-year-old farmer didn't wait to hear what experts had to say when Mount Tambora started being rocked by a steady stream of quakes. He grabbed his wife and four young children, packed his belongings and raced down its quivering slopes.

"It was like a horror story, growing up," said Hasanuddin, who joined hundreds of others in refusing to return to their mountainside villages for several days despite assurances they were safe.

Bizarro Earth

Scientists Concerned By Continued Eruptions At Alaskan Volcano

Cleveland Volcano
© 2010 – GeoEye
This GeoEye IKONOS image shows a faint plume issuing from Cleveland Volcano at 2:31 PM on September 14, 2010. Red in this image highlights areas of vegetation detected by the near-infrared channel.
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.

As previously reported here on RedOrbit, an eruption warning was issued by the Alaska Volcano Observatory in late July.

At that time, the Daily Mail warned that Cleveland Volcano "could be poised for its first big eruption in ten years," and that experts believed that it could "erupt at any moment, spewing ash clouds up to 20,000 feet above sea level with little further warning."

Nearly eight weeks later, such an eruption remains a definite possibility.

"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.

Bizarro Earth

US: Alaska - Aleutian volcano's behavior a challenge for scientists

Image
© Unknown
A volcano in Alaska's Aleutian Islands has been in an unusual low-level eruption for two months, raising the spectre of an explosive eruption with little warning, officials at the Alaska Volcano Observatory said on Friday.

Cleveland Volcano, a 5,676-foot peak located 940 miles southwest of Anchorage, continues to expel lava out its crater, a low-level eruption that began in mid-July, scientists at the Alaska Volcano Observatory said.

Satellite imagery shows a lava dome growing inside the volcano's crater. Satellite data also shows continued heat generated from the volcano, according to the observatory, a joint federal-state organization.

So far, there have been no signs of ash clouds. But those could come with little warning, scientists said. "The big thing we're concerned about is an explosive eruption," said Steve McNutt of the University of Alaska Fairbanks, a coordinating scientist for the observatory.