Scientists says this morning's steam burst at Mount St. Helens was just a 'prelude'

Tuesday, August 20, 2019

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Earthquakes indicate magma apparently is still pushing up under the volcano and could result in a real eruption. That means it could shoot ash tens of thousands of feet in the air or ooze lava on the crater floor. This morning's burst about 9:30 was similar to the Friday steam burst. It blew some dust or old ash over the crater rim to an elevation of about 12-thousand feet. Most of it fell to ground on the volcano itself. The alert remains at Level Three, meaning an eruption is imminent. However, scientists do not expect much impact outside the remote, unpopulated area around the volcano in southwest Washington. They do not expect a repeat of the 1980 blast that killed 57 people. U-S Geological Survey scientist Tom Pierson says the biggest concern is the possibility of an ash cloud that could dust some nearby communities. Pilots also are warned to avoid the plume as they would a thunderstorm, informs KIFI. According to Reuters, Mount St. Helens spewed more steam and ash on Monday as government scientists remained on alert for a larger eruption at the Washington state volcano, which woke last week after 18 years of slumber. Mount St. Helens, which in 1980 killed 57 people when it erupted violently, continued to increase its activity, following a week of tremors and an minor eruption on Friday. "We could go into a more substantial event without warning," Willie Scott, a U.S. Geological Survey geologist, told reporters. The 1980 eruption of Mount St. Helens was one of the most devastating in modern history. In addition to the heavy casualty toll, it destroyed more than 200 homes and flattened acres of evergreen spruce forest. The volcano continued to have a series of smaller eruptions until 1986. The U.S. Geological Survey kept its warning level at a Level 3-Volcano Alert and kept off-limits a visitor center at the Johnston Ridge Observatory about five miles from the volcano's crater as a safety precaution. Government scientists said that low-frequency earthquakes, carbon dioxide gas, and swelling in the lava dome created after the 1980 eruption all pointed toward the buildup of magma under the mountain. Although scientists have said that they do not expect an explosion that would cause any deaths, they are concerned about the impact of any ash on air traffic and humans following an explosion. Mount St. Helens is located about 100 miles south of Seattle, and 50 miles north of a busy airport at Portland, Oregon. A thick plume of steam rose from the crater of Mount St. Helens on Monday at around 9:30 a.m., following a similar discharge 11 hours earlier. Scott also said that the lava dome in the volcano's crater, as well as a glacier nestled next to it, had risen significantly. The Federal Aviation Administration also notified nearby aircraft of Monday's steam eruption, and directed them to avoid the steam and ash plume, said Mike Fergus, an agency spokesman. Aircraft engines can be stalled by ash. The violent blast in 1980 blew off the top of the mountain and reduced the summit of Mount St. Helens to 8,364 feet from 9,677 feet. Smaller eruptions in the lava dome happened in 1986 but caused no serious damage. U.S. Geological Survey officials reported that the volcano began releasing steam and ash around 1 p.m. ET. They are uncertain as to whether larger eruptions are still to come. Since Sept. 23, a recurring swarm of shallow earthquakes at the volcano 95 miles south of Seattle have kept geologists on high alert. Within hours of an official Notice of Volcanic Unrest being issued on Friday, the steam and ash rose from the crater for 24 minutes, followed by continuous tremors in the days since. Today, scientists detected rhythmic quakes known as harmonic tremors that often precede eruptions, with some lasting up to 90 minutes. The U.S. Geological Survey remains at its highest alert status, a Level 3, and airspace and visibility around the mountain are extremely limited. Although scientists do not anticipate an eruption comparable to the catastrophic explosion of 1980, which killed 57 people and coated towns 250 miles away with ash, American Red Cross disaster preparedness experts are urging residents to act now and take the necessary precautions

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