Magnitude 5 Earthquake, bulge of magma on North face exploded due to landslide
Where the Juan de Fuca is being subducted the North American plate
How big?
VEI 5, Column of ash rose 80,000ft
(Volcanic Explosivity Index)
Primary Effects? PHYSICAL
Large areas covered in ash (deposited in 11 states)
Reduced in height
Every tree in 25km blast zone destroyed
Primary Effects? HUMAN
57 died - pycrolastic flow
Road + air communications destroyed/broken
Flood water washed away bridges etc...
Secondary Effects?
Loss of income in short-term from 250km former top-class salmon and trout rivers
Flights + other forms of transport disrupted for several days after
Tourism in area decreased
Immediate Response
People evacuated by May 17th
Volcano closes monitored
Visibility was decreased by falling ash so much that the interstate 90, Seattle to Spokane was closed for 1 + 1/2 weeks
Engineers pumped water out of Spirit Lake so that it was not in danger of overflowing and causing floods
Long-Term Responses
10 million trees replanted
Several months after eruption, people suffered emotional + stress problems so money was requested for mental health programmes to assist those badly affected
Thousands of papers written to help volcanologists improve their ideas of volcanoes
