Winds kick up century previous volcanic ash in Alaska

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Whereas western U.S. states had been affected by hazy purple skies from wildfires, Alaska on Monday was coping with an air high quality downside born a century in the past

ANCHORAGE, Alaska — Whereas western U.S. states had been affected by hazy purple skies from wildfires, Alaska was coping with an air high quality downside born a century in the past.

Sturdy southerly winds picked up free ash from a 1912 volcanic eruption, sending an ash cloud about 4,000 ft (1,219 meters) into the sky on Monday.

There have been no studies of ashfall in close by communities close to Katmai Nationwide Park, well-known as the situation the place brown bears stand within the Brooks River and catch salmon, however pilots had been warned in regards to the cloud as a result of the ash can stall engines.

“Mainly these kinds of occasions occur each spring and fall when sturdy winds choose up ash from the 1912 Novarupta eruption,” mentioned Kristi Wallace, a U.S. Geological Survey geologist on the Alaska Volcano Observatory.

The three-day eruption, one of many world’s largest, started June 6, 1912, and despatched ash as excessive as 100,000 ft (30,480 meters) above the Katmai area, positioned about 250 miles (402 kilometers) southwest of Anchorage. The USGS estimates 3.6 cubic miles (15 cubic kilometers) of magma was erupted, about 30 instances what spewed from Mount St. Helens in Washington state 40 years in the past.

The Novarupta eruption was essentially the most highly effective of the 20th century and ranks among the many largest in recorded historical past.

The ash was deposited in what’s now often known as the Valley of Ten Thousand Smokes. “Nearly 600 ft (183 meters) of ash on the market that’s not vegetated,” Wallace mentioned.

Cloudy skies obscured satellite tv for pc imagery on Monday, however a pilot flying at about 20,000 ft (6,096 meters) first reported the ash cloud, Wallace mentioned.

That was confirmed by a pilot flying at about 2,000 ft (610 meters).

The observatory issued a press release alerting those that this was not a brand new eruption from one of many seven volcanos within the Katmai area, however simply excessive winds kicking up the Novarupta ash.

“We all know that what’s getting kicked up isn’t simply glacial mud, mineral mud that you may see just about in all places else in Alaska,” Wallace mentioned. “These sorts of mud storms occur in all places. However once they occur there, we all know that the fabric that’s being picked up is predominantly volcanic ash.”

The winds had been solely about 30 mph (48 kph), mentioned Michael Kutz, a meteorologist on the Nationwide Climate Service workplace in Anchorage. The cloud moved north from the Katmai area, and so they had no studies of ashfall.

Widespread rains Tuesday within the Bristol Bay area prompted the cancellation of ash advisories, Kutz mentioned.

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