Tuesday, March 20, 2012

AVO Sends Team To Mt. Iliamna To Check Gas/Temps [UPDATED]

AVO scientists have sent a team of geologists on a fly-by mission to Mt. Iliamna, Alaska's restive volcano that has been showing signs of activity since January. The apparently successful mission to go to the volcano to check gas levels and temperatures on the summit fumeroles has produced results, and AVO is expected to release their findings today on their website (http://avo.alaska.edu).

Mt. Iliamna has been experiencing heightened levels of seismicity for some time, but recently in January there were some rather intense quake swarms, at very shallow depths (some swarms were less than 1km underneath the surface), with some quakes registering up to magnitude 3.7. AVO has subsequently raised the alert level to "Yellow"(watch), and has actually directed one of their webcams to watch the volcano visually (below picture).


Live webcam snapshot from AVO.alaska.edu
Iliamna does not have a record of historical eruptions, however AVO and GVP state that it's last eruption was approximately 140-200 years ago. Active fumeroles exist at the summit, and the last activity in 1996 was similar to the current level of activity.The 1996 quake swarms were also thought to be magma dike intrusion, much like today's swarms. AVO scientists stress that this does NOT mean there will be an eruption, however I would wager that with several dike intrusions, the magma will try to find some way to the surface. In my opinion, a minor eruption is very likely at Iliamna in the coming months or years.

It is anyone's guess as to what characteristics an eruption at Iliamna would take on. It is a stratovolcano, and part of a subduction zone, so like most Aleutian and Alaskan volcanoes, it would likely be an explosive event followed by dome growth and thick lava effusion. For now, AVO is monitoring the volcano, and so am I!

*****UPDATE 3/20/2012*****

AVO has completed their initial survey of Iliamna volcano and released the following news:

"Seismicity at Iliamna Volcano remains above background. Data from Saturday's gas and observation flight indicate that the volcano is emitting elevated levels of sulfur dioxide and carbon dioxide, consistent with a magmatic source. It is not know, however, if this is a newly intruded magma, or whether new pathways for gas from preexisting magma have caused the increased gas flux. The amount of gas being emitted is broadly similar to levels seen in 1996-1997, when a likely magmatic intrusion but no eruption occurred at the volcano.

Observers on the flight saw vigorous and plentiful fumaroles (gas vents) at the volcano's summit, consistent with the elevated gas emissions. No obvious signs of recent rockfall, large areas of newly exposed bedrock, or unusual disturbance of the glacial ice were observed. Some deformation of the ice at the headwall of the Red Glacier on the east side of the summit was seen, but it is not clear this is related to the current volcanic unrest; avalanching of the glacier is common on this very steep area and was last seen in 2008."

So it does appear at this time that activity has at least increased visually, indicating rising temperatures from deep below. Iliamna is officially a volcano to keep an eye on!

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