Winds kick up century-old volcanic ash

摘要

While Western states were suffering from hazy red skies due to wildfires, Alaska was dealing with an air quality problem born a century ago.Strong southerly winds picked up loose ash from a 1912 volcanic eruption, sending an ash cloud about 4,000 feet into the sky Monday. There were no reports of ash fall in nearby communities near Katmai National Park and Preserve, famous as the location where brown bears stand in the Brooks River and catch salmon, but pilots were warned about the cloud because the ash can stall engines. "Basically these sorts of events happen every spring and fall when strong winds pick up ash from the 1912 Novarupta eruption," said Kristi Wallace, a U.S. Geological Survey geologist at the Alaska Volcano Observatory. The three-day eruption, one of the world's largest, began June 6, 1912, and sent ash as high as 100,000 feet above the Katmai region, located about 250 miles southwest of Anchorage. USGS estimates 3.6 cubic miles of magma erupted, about 30 times what spewed from Mount St. Helens in Washington state 40 years ago.