September 18, 2011
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.
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.
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.
Twenty-one confirmed eruptions have taken place at Cleveland Volcano over the past 230 years, with the only fatality coming in 1944, when a US soldier stationed there during World War II went missing and was presumed dead following a VEI 3 level eruption. The mountain erupted twice in 2010 and three times in 2009.
As of 11:53 a.m. Saturday, the Aviation Color Code at the volcano was Orange, with the following notice posted on the Observatory website: "No activity observed in mostly cloudy satellite images from the past day. No ash emissions have been observed during this current eruptive episode that began in mid-July 2011. No other new reports have been received regarding the volcano."
"The current episode of dome growth resumed around September 3," the Observatory status report added. "A growing lava dome in the crater increases the possibility of an explosive eruption, but does not necessarily indicate that one will occur. Short-lived explosions could produce ash clouds that exceed 20,000 ft above sea level. These events can occur without warning and may go undetected in satellite imagery for hours. If lava dome growth continues, it could overflow the crater rim to produce a lava flow and/or collapse to produce pyroclastic flows. Collapse of a lava flow or dome would likely result in the generation of a volcanic ash cloud."
Image Caption: 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. Credit/Copyright: 2010 - GeoEye
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