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Period: to
The lead up and end of Mount St. Helen's Eruption
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Mudflows
Mudflows beginning, because of volcanic debris. -
Ash Rises
Ash rises making a mushroom clous 12 miles above the volcano. -
The End of The Big Eruption
The eruption subsides. 540 million tons of ash was expelled throughout this procss. -
The Trigger
An earthquake with a 4.2 magnitude north of the summit causes avalanches on the mountain -
Seismologists Predict
They predicted Mount St. Helen's will have its first eruption, but are reluctant to say it publicly -
Multiple Earthquakes
The mountain experiences as many as 20 earthquakes an hour -
Closing of Areas
Due to five earthquakes greater than 4.0 occur Spirit Lake Information Center and roads leading up to the mountain are closed. There are flight restrictions near the volcano. -
Explosions Start
A hole appears at the summit which causes a 4.7 earthquake and 200 foot wide crater. Hundreds of people are evacuated from 1.5 mile radius. -
Multiple Explosions
93 explosions happen in one day -
State of Emergency
County Commissioners declare a state of emergency -
Still Smoking
Steam and ash reach around 20,000 feet into the sky. Some workers return to work near the mountain. -
Crater Getting Bigger
The crater is now 1,500 feet wid and 300 feet deep. -
Serious of Explosions
Multiple explosins last four hour which has been the longest recorded yet. -
Bulging
The northern flank of the mountain is starting to bulge outwards. -
Bulging Continues
The bulge is continuing to grow about five feet a day. -
The Eruption Begins
A mile beneath the volcano a 5.1 earthquake takes place. This causes rock to slide into the crater. -
The Bulge
The bulge beging to slide causing an avalanche that has debris moving at 180 mph. -
Explosion
Where the bulge was comes a huge explosion. -
The Beginning of the Blast
A huge blast of rock, ash, and gases head into the sky. The power of the blast increases causing anything in an 8 mile radius to be obliterated. -
Path of Destruction
Anything within a 15 mile radius from the volcano is destroyed. -
In the United States
An ash cloud arrives in central United States. -
Disappearing of Ash
Most ash has now settled, but some of the smaller pieces stay suspended in the upper atmoshere for years. -
Still Alive
The volcano erupts again after several week which forms a dome of lava on the crater floor. -
Eruptions Continue
After a few eruptions most of the dome gets destroyed. The volcano has periodic eruption which has caused the dome to rise more than 800 feet.
