Plate Tectonics Case Studies-Mount St Helens Flashcards
(10 cards)
Where
Washington, USA, Cascade Mountains
What
Volcanic eruption, pyroclastic flows, Lahars and floods
When?
18th May 1980
Signs in march, small earthquakes, bulge on side, ash/steam released
Why
Destructive plate boundary, Juan de Fuca plate under North American plate
Type
Composite
Impacts
Cost of $1.1 billion.
200 homes destroyed
1000 flights cancelled
Airports closed 2 weeks
Impacts
57 killed,
Timber industry suffered
Unemployment
Hundreds lost homes
Impacts
27 bridges, 24km railway, 300km road destroyed
31 ships stranded-mudflows
Responses
Face masks, reduced ash intake
Emergency shelters
Ash cleanup organisations
Responses
More trees replanted, 18.4 million over 45,500 acres
Shipping channels cleared
Water monitored