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Mount St. Helens
Transcript of Mount St. Helens
Mount St. Helens
Mount St. Helens is an active volcano located in Skamania County, Washington, in the Pacific northwest region of the United States. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring Of Fire that includes over 160 active volcanoes.
Mount St. Helens: Today
Mt. St. Helens Monitoring
In 1982, President Ronald Reagan and the U.S. Congress established the Mount St. Helens National Volcanic Monument, a 110,000 acre area around the mountain.
Mount St. Helens and surrounding areas from space.
March 15, 1980 - Mount St. Helens enters a week in which more than 100 earthquakes are recorded.
March 20 - A magnitude 4.2 quake just north of the summit triggers avalanches on the mountain.
March 24 - The mountain experiences as many as 20 earthquakes an hour.
March 25 - Five earthquakes greater than 4.0 occur in one hour. A large crack appears in the snow on top.
March 27 - Earthquakes become more frequent. A hole in the summit icecap appears, followed by a loud boom, ash and smoke, a 4.7 earthquake and a 7,000-foot-tall black plume. A 200-foot-wide crater is left behind.
April 1 - Explosive plumes of steam and ash reach 20,000 feet. Scientists begin to anticipate the explosion of magma, the molten rock welling up from deep within the Earth.
April 3 - Summit crater is now 1,500 feet wide and 300 feet deep.
April 8 - A series of explosions lasts four hours, the longest yet.
April 19 - Scientists notice that the mountain's north flank is bulging outward.
8:32 and 21 seconds - The bulging north flank begins to ripple, churn and slide away in blocks. A giant debris avalanche approaches speeds of 180 mph.
8:32 and 45 seconds - A huge explosion blasts out from where the north face slid.
8:33 - The volcano, which one geologist calls a superheated champagne bottle shaken for two months, is uncorked. A lateral blast of rock, ash and hot gases heads northward.
8:33 and 20 seconds - The blast increases to nearly supersonic speed and overtakes the debris avalanche. Within an eight-mile radius, virtually everything is obliterated or carried away.
8:34 - Within a 15-mile radius, everything is flattened. Enough timber is blown down to build 300,000 two-bedroom homes.
8:47 a.m. - A vertical column of ash and steam rises in a mushroom cloud 12 miles above the volcano. The cloud generates lightning.
5:30 p.m. - Eruption subsides after ejecting 540 million tons of ash.
July 22 - Several eruptions destroy most of the dome. The volcano continues to have periodic eruptions into 1984, with the dome rising more than 800 feet. At the current rate of growth, it will take a century for Mount St. Helens to reach its former height.
Mt. St. Helens mushroom cloud, 40 miles wide and 15 miles high.
Ariel view of Mount St. Helens
The next video you are about to see, shows a time-lapse view of Mount St. Helens' recovery that NASA made, showing yearly Landsat images from 1970 to 2011. The first few images show vegetation in red. New instruments in Landsat 5 allowed for true-color images from 1984 onward.
Clouds of ash from Mount St. Helens are shown over the airport in Ephrata, Wash., a day after the blast. Traces of ash were blown across the United States in three days, and circled the Earth in 15 days.
Thirty years after Mount St. Helens blew its top, the peak is still the second most dangerous volcano in the United States, according to government estimates.
Prior to the 1980 eruption, Mount St. Helens was the fifth-highest peak in Washington. It stood out noticeably from the surrounding hills because of the symmetry and extensive snow and ice cover of the pre-1980 summit cone, earning it the nickname "Fuji-san of America".
Devastation to the Surrounding Area
Devastation to the surrounding area of Mount St. Helens is easily seen. Once a green lush area, now has a hard and grey surrounding. Though it may have taken years, Mt. St. Helens area is now growing back greener than ever. Scientists have been able to follow the growth process of plant and forest life since the day of the eruption, May 18th, 1980. Mt. St. Helens eruption has given scientists the opportunity to watch an ecosystem regrow naturally after a disaster.
The first plant to re-appear was a prairie lupine
Due to the eruptions of 1980-86 and 2004-2008, Mount St. Helens has had the best seismic monitoring network of all volcanoes in the Cascade Range. It is also the most seismically active volcanoes in the Washington and Oregon Cascades.
Seismic data recorded by this network have been used in many studies, including:
•forecasting eruptions and detecting explosions
•determining eruption dynamics
•developing models of the magmatic system beneath Mount St. Helens
•determining the on-the-ground processes responsible for various types of seismic signals
•detecting repetitive events (or earthquake families), including the first published study of repetitive events in a volcanic setting
Seismic monitoring station SWFL—solar panels are used to recharge the batteries and keep the station running, Mount St. Helens.
Mount St. Helens has several video cameras set up to view the mountains activity.
August 20, 2013
Watch this video, I thought this was a great video of the eruption!