Mt. St. Helen’s Washington State Katie Reibling & Jessie Radel

First signs of life Thursday, March 20 th magnitude earthquake centered beneath the volcano. earthquake centered beneath the volcano. Most northwest newspapers completely ignored this earthquake President Carter's announcement of the Moscow Olympics boycott dominated the news

March 27 th -30 th 1980 March 27th, first puff of ash. The small explosion left a 250 foot wide crater in the otherwise perfect cone. On March 30th there were a record 79 earthquakes recorded on the mountain

April 3 rd 1980 the first harmonic tremors were recorded signaling the movement of magma somewhere deep within the dome. The crater was by now 1,500 feet wide. Explosions of ash, rock and ice chunks were a daily occurrence.

The bulge In April a noticeable bulge formed on the north side of the mountain. Building of magma, hot gasses and pressure Grew five feet per day

The Eruption May 18 th 1980

statistics Largest land slide in history 5.1 magnitude quake Elevation dropped from 9,677 to 8,363 ft. All of the rock ash melted snow and debris rushed down the mountain into the Toutle River Valley at speeds higher that 175 mph

Impacts 57 People were killed 5,000 black tailed deer,1,500 Roosevelt Elk, 200 Black Bears, millions of small animals 200 Black Bears, millions of small animals Toutle River valley 3 billion dollars in damage

Plate Tectonics The Juan de Fuca plate is subducting under the N. American plate Magma moved into the shallow part of the volcano through out the many minor eruptions So much pressure made the north bulge give out. bulge give out.

Will it Happen Again? The slow collision of the North American Plate and the Juan de Fuca plate is causing the Juan de Fuca to slowly move beneath the Pacific Northwest Scientists predict it will erupt again they are not sure when or how much volcanic activities it will bring.

Monitoring Mt. St. Helens today t-conditions/ t-conditions/

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