A Alaskan Volcano Has Arrived, And We Might Finally Know What's Stopping It

A Alaskan Volcano Has Arrived, And We Might Finally Know What's Stopping It ...

Geologists predicted the Westdahl Peak volcano to erupt again by 2010, but it is still intact and restless pointing to flaws in our forecasting.

A naive but serious task to protect people and reduce aviation hazards is to look into just how rapidly the volcano will go. This is why many factors are being identified, and this absence of explosion has highlighted one topic that has been overlooked.

"Volcanic forecasting involves a wide spectrum of factors, including the depth and depth of a volcano''s magma chamber, the rate at which magma fills that chamber, and the strength of the rocks that contain the chamber, for example," says geologist Lilian Lucas.

TheWestdahl Peak Shield volcano, located in western Alaska, along the Aleutian Islands chain, was last blown in a series of explosions between 1991 and 1992. It has continued to swell since, threatening further action with an active magma chamber leaking away around 7.2 kilometers (4.47 miles) beneath its surface.

The most obvious characteristic that differs from many volcanoes elsewhere in the world is that a one-kilometer-long ice cap is also blanketing the Westdahl Peak volcano.

"Our numerical analyses demonstrate that the presence of an ice cap (13 kilometer thick) increases the average repose interval for a magma system," Lucas and colleagues write in their paper.

Researchers at the University of Illinois found a linear relationship between ice-cap thickness and the volume changes required within the volcano to overcome the strength of the encasing rock and explode. Magnma is also dependent on magma production rate at a volcano the magma flux.

The team examined the magma chamber''s dimensions, geometry, and magma flux. For the Westdahl system, the pressure from the ice cap adds about seven years of dormancy, compared to methods without the ice.

"These increases in time might seem insignificant on a geologic scale, but they are significant on the human time scale," said geologist Patricia Gregg. "Going forward, it will be important to consider glacial ice cover in future forecasting efforts."

While the ice cap may be responsible for some of Westdahl''s unimaginable stability, there''s still something to the story, according to researchers. Their study assumed a constant flux, which does not capture the dynamics of other systems such as those that have been long dormant.

"We do not know how close the system is to failure, and recent geodetic data have not yet been studied to update our assumptions about the system''s flux rate," they say.

"If the flow into Westdahl''s magma reservoir has decreased in recent years, while the system is still nearing failure, seasonality might ultimately play a larger role than projected."

Though the system approaches a certain threshold and flux is low, the weight of ice caps comes to play, according to the team, to the point where even seasonal variation in the ice above may be enough to cause the eruption to fall.

According to geologist Yan Zhan, climate change and glacial ice melt will be beneficial to Westdahl Peak and other high-latitude volcanoes in the future.

"Accounting for excessive pressure frompolar ice caps is another critical, yet uncomfortable, variable," Lucas declares.

Frontiers in Earth Science has published this research.

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