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More on Okmok

Sorry about the brevity of this update, but I’m exhausted.


From the Alaska Volcano Observatory (AVO):

At this time, based on AVO analysis of satellite data, ash is

continuing to erupt from a composite cinder and spatter cone called

Cone D in the eastern portion of the 6-mile wide caldera or crater of

Okmok. It appears that the eruption is very water-rich due to

interaction of rising magma with very shallow groundwater and

surficial water inside the caldera. We have few direct observations

into the caldera and details of the current event remain unknown.

The current activity differs in character from the past three

significant eruptions at Okmok in 1945, 1958, and 1997. All of these

eruptions occurred at a cinder and spatter cone on the far western

portion of the caldera floor, Cone A. In general, each eruption was

mildly to moderately explosive with most ash clouds produced rising

less than 30,000 ft above sea level. Each eruption also produced a

lava flow that traveled about 5 miles across the caldera floor.

Based on past eruptions at Okmok and our analysis of the current

episode of activity, we would expect this event to continue for

several weeks and possibly longer. The position of the vent in the

eastern caldera adjacent to a shallow lake suggests that water will

continue to play a role in increasing the explosivity of the eruption

resulting in significant ash and steam production. If the eruption

follows patterns of previous Okmok events, lava will eventually reach

the surface to form lava fountains, spatter accumulations, and

possibly a lava flow. It is also possible that explosivity could

intensify at any time.

Sounds like a good one underway!


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