Posts Tagged ‘Aleutian Islands’

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Thar She Finally Blows – Cleveland Volcano Spewing 15,000 Feet of Ash

29/12/2011

The Alaska Volcano Observatory said satellite images showed Cleveland Volcano had spewed ash 15,000 feet (4,572 meters) into the air in a cloud that moved east-southeast. U.S. Geological Survey scientist-in-charge John Power called it a small explosion.

“It’s not expected to cause a disruption to big international air carriers,” he said.

But the event drew strong interest from air carriers.

“Any time you put an ash cloud up into the atmosphere, the airlines, the air carriers, air freight companies — it’s a major concern,” Power said.

The ash cloud was significant enough to raise the alert level from yellow, representing elevated unrest, to orange, representing an increased potential of eruption, or an eruption under way with minor ash emissions or no emissions.

Cleveland Mountain is a 5,675-foot (1,729-meter) peak on uninhabited Chuginadak Island about 940 miles (1,512 kilometers) southwest of Anchorage.

Scientists in July noted increased activity in the crater at the summit of the volcano. Satellite images showed lava building and forming a dome-shaped accumulation.

Chris Waythomas of the USGS said in September that lava domes form a lid on a volcano’s “plumbing,” including the chamber holding the magma. When they grow big enough, lava domes can become unstable and will sometimes collapse. When the magma chamber decompresses it can lead to an explosion as the conduit inside the volcano suddenly becomes unsealed and gases escape.

Radar images earlier this month showed the dome had cracked and subsided, Power said.

The Federal Aviation Administration and the airline industry get concerned for trans-Pacific flights when an ash cloud has the potential to exceed the 20,000-foot (6,096-meter) threshold, as Cleveland Volcano has done in the past.

Cleveland Volcano’s last major eruption was in 2001. It has had bursts of activity nearly every year since then, and the ash cloud Thursday was not out of character.

“It’s not unexpected for a volcano like Cleveland to do things like this,” Power said. “Unfortunately, Cleveland is one of those that is so remote, we have no on-ground monitoring or instrumentation there, so it’s hard for us to pinpoint things any more accurately than we can do with satellite imagery.”

The observatory Thursday morning had no satellite images of the crater after the eruption.

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NOAA Report on Solar Geomagnetic Storm that Partially Hit Earth – Coinciding with Earthquake & Volcano Activity

27/09/2011

The National Oceanic & Atmospheric Administration has been reporting on high solar activity for the past while.  Here is the news for the past 3 days, updated today.  It is important to note that the September 26th report emphasizes that “aurora watchers in Asia and Europe will be favourably positioned” and we now have had reports of much earthquake and volcanic activity, most notably the swarms in Spain (see El Hierro Volcano Article), Greece and Turkey, as well as the ones around the Aleutian Islands in Alaska, (see Cleveland Volcano Article) as well as the 5.3 MAG that hit the North West Territories (see 4 Significant Quakes/NWT Article). There are many more places that have been affected – all along the Pacific Ring of Fire.  Drop in news of earthquake drills and we have a bit of a rocky road perhaps ahead (see Earthquake Drill in US, NZ, BC Article)? (Hey, I’m just saying, but what do I know?)

If you would like to see what an Aurora looks like from space, here is a video take from the International Space Station around September 19th 2011 and its quite spectacular to see.  The path taken here is eastwardly from Madagascar along to northeast Australia, hence the term ‘aurora australis’. Aurora borealis north & aurora australis south hemisphere.

REPORTS FROM NOAA – PAST 3 DAYS

2011-09-27 17:33   Update on the September 26/27 Geomagnetic Storm

The Geomagnetic Storm that began yesterday is quieting down, though we aren’t quite back to quiet conditions yet.  High speed solar wind is coming in behind the Coronal Mass Ejection and these winds are keeping things slightly active on the space weather front.  The region on the Sun that produced this activity is in a favorable position to cause further problems, but it is starting to weaken.  It remains a threat, though diminishing.  Yesterday, there would have been problems with high accuracy GPS and there was a noted issue with the FAA’s Wide Area Augmentation System (WAAS), where the Vertical Error Limit was exceeded.  WAAS is used to provide high accuracy GPS in the areas around airports.  Much more information about this storm is available on the SWPC Facebook page.

2011-09-26 19:00   

The fast Coronal Mass Ejection (CME) that erupted from NOAA Active Region 1302 arrived this morning at 1237Z (8:37am Eastern Time).  It has kicked off moderate (G2) geomagnetic storms for low latitudes, but high latitudes are seeing severe (G4) levels of activity.  Aurora watchers in Asia and Europe are most favorably positioned for this event, though it may persist long enough for viewers in North America.  The bulk of the CME missed the Earth, meaning the storm intensity and duration are less than what they would have been in the case of a direct hit.  We are posting frequent updates on the SWPC Facebook page, which you can follow (here).

2011-09-24 22:00   

NOAA Region 1302 remains impressive and active as it continues its transit across the visible disc.  As shown in the GOES X-ray plot below, 1302 produced an R3 (Strong) and multiple R2 (Moderate) flares today.  Intermittent degradation to High Frequency communications occurs on the daylight side of the Earth during each respective flare.  Also, the slow rise of energetic protons near Earth has flattened out and we are hovering right around the S1 threshold (NOAA Solar Radiation Storm Scales).  A fairly fast Coronal Mass Ejection (CME) associated with the long duration R2 flare is partially directed at Earth (long duration meaning long-lasting in time and wider in the graph below, as opposed to the impulsive flares that spike quickly).  We won?t see the bulk of this CME, but a glancing blow is predicted for late evening Eastern Time on the 25th (or right around start of day GMT on the 26th).  Geomagnetic Storm levels reaching the G1 (Minor) level are likely with isolated G2 (Moderate) possible, particularly at high latitudes.  1302 remains active so stay tuned for further updates.

source: NOAA

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Aleutian Volcano Behavior a Challenge for Scientists | News

18/09/2011

 09.18.11 12:24 pm – ANCHORAGE, Alaska, Sep 18 (via bdnews24.com/Reuters) – 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.

One worry is that the dome could seal off the crater vent entirely, causing pressure to build until it is released explosively, McNutt said. Or the dome could topple, triggering a molten flow down the mountain that releases gas and ash into the atmosphere while lava and rocks tumble, he said.

While Cleveland is one of Alaska’s most active volcanoes — erupting about once a year over the past decade — its long-running lava flow and dome buildup is something different from past behavior, scientists said.

Past eruptions have been mostly brief and explosives, with relatively small ash clouds, said Chris Waythomas, acting scientist-in-charge at the observatory.

Interference with air travel is the most immediate risk posed by Alaska’s volcanoes because the peaks lie directly in the flight path used by jets traveling between Asia and the US West Coast.

Jet engines can be damaged or shut down abruptly when they suck in gritty volcanic ash.

A KLM airliner abruptly dropped more than 14,000 feet when it flew through ash from erupting Redoubt Volcano in 1989. The badly damaged jet landed in Anchorage.

For scientists at the observatory, Cleveland’s remoteness poses special challenges. Scientists have not been able to station seismic instruments on Cleveland, as they have on volcanoes closer to Anchorage, so they have no real-time data.

Instead, they must rely on satellite imagery, which is often disrupted by cloud cover, and on other measurements that can be delayed.

Getting seismic equipment on Cleveland has so far proved too costly a proposition, the scientists said.

“It’s been on our list for years,” McNutt said, adding that such a project could cost up to $1 million. “It’s just a very expensive and very difficult place to work,” he said.

 
Aleutian volcano’s behavior a challenge for scientists | Americas | world.bdnews24.com.

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