USA, California:

Salton Sea Volcano Mystery Solved (LiveScience.com)

Projectile point made from Obsidian
Butte obsidian helped solve the mystery.

(Courtesy Janet C. Harvey/Axel Schmitt)

Researchers may need to revise estimates of the potential hazard posed by the Salton Buttes — five volcanoes at the lake's southern tip. The Salton Sea area is home to over 700 MWe of installed geothermal capacity.

The buttes last erupted between 940 and 0 B.C., not 30,000 years ago, as previously thought, a new study detailed online Oct. 15 in the journal Geology reports. The new age — which makes these some of California's youngest volcanoes — pushes the volcanic quintuplets into active status. The California Volcano Observatory, launched in February by the U.S. Geological Survey (USGS), already lists the area as a high threat for future blasts.

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