Please enable JavaScript.
Coggle requires JavaScript to display documents.
Mt Saint Helen (1980) (Responses and management (Preparation (As early as…
Mt Saint Helen (1980)
Responses and management
Prediction
Using Seismograph
1/ 3 / 1980, new seismograph at the University of Washington went into operation
March 20, recorded a magnitude 4.2 earthquake
March 25 - 27, quakes of magnitude 4.0 is recorded
-
However, they mispredicted the eruption by weeks (it happened too soon)
Preparation
-
-
-
-
As early as March 25, the US Forest Service set up a red zone closing off the whole mountain above the timber line
However, portions of the red zone boundaries bore a closer resemblance to divisions between public lands and lumber company property than to defined geologic hazard zones.
Response
Short term
The National Guard also issued clean water, emergency food rations and medical supplies
The National Guard flew helicopter rescue missions into the blast zone for 2 weeks and rescued 130 people.
-
Long term
-
-
The volcano is now monitored constantly by the USGS and clear plans have been made to
prepare and warn people in the area beyond the immediate blast zone to make them aware of the risks of ash clouds
Facts and figures
Earthquake at 8:32:17 am on Sunday, May 18,1980
-
Causes
-
Result of magma at shallow depth below the volcano -> huge bulge and a fracture system on the mountain's north slope
Impacts
Hundreds of square miles were reduced to wasteland, causing over a billion U.S. dollars in damage ($2.89 billion in 2015 dollars), thousands of animals were killed, and Mount St. Helens was left with a crater on its north side
Approximately 57 people were killed directly from the blast and 200 houses, 47 bridges, 15 miles (24 km) of railways and 185 miles (298 km) of highway were destroyed