Thursday, October 16, 2003

Volcano Danger

Vulcanologist Bill McGuire discusses Italy's preparations - in reality the lack thereof - for future eruptions of Mount Vesuvius in The Guardian today. He also helpfully points out some other danger zones, including three in the United States:

Yellowstone
Over the past 2m years, Yellowstone in Wyoming has hosted three gigantic eruptions, each of which formed a giant crater, or caldera. Recently, a large swelling has been detected beneath Yellowstone lake, possibly reflecting an accumulation of steam that may blast a crater through the crust. The area has been closed to tourists.

Mammoth Lakes
This part of northern California's Long Valley caldera has been particularly restless since 1980, increasing worries over a future eruption. Scientists at the Long Valley observatory stress that in any single year the chances of an eruption are small, but agree that recent earthquake swarms, ground swelling and releases of carbon dioxide increase the chances of an eruption in the near future.

Three Sisters
Sometime after 1996, the ground surface started to swell in this volcanic region of Oregon. By 2000, uplift had reached 10cm and swelling is continuing at about 2cm a year. Scientists interpret this as evidence of magma accumulation at around 6-7km depth and warn that continuation of uplift may lead to an eruption.

Scientists have been watching the Mammoth Lakes area closely for several years, and now Yellowstone is starting to give anxiety. A modern eruption of the Yellowstone supervolcano would, simply put, destroy the entire United States, and the situation needs to be monitored very closely.

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