NOVA

Mystery of the Megavolcano

Student Handout

Volcano Suspects: Description


Mt. St. Helens Mount St. Helens
Location: Washington
Volcano Type: Stratovolcano
Summit Height: 2,549 m
Crater/Caldera Size: 2 x 3.5 km
Last Known Eruption: 2006
Largest Eruptive Volume: 1 km3

caldera Crater Lake
Location: Oregon
Volcano Type: Caldera
Summit Height: 2,487 m
Crater/Caldera Size: 8 x 10 km
Last Known Eruption: ~2500 BC
Largest Eruptive Volume: 35 km3

Lassen Peak Lassen Peak
Location: California
Volcano Type: Stratovolcano/Dome
Summit Height: 3,187 m
Crater/Caldera Size: 213 x 122 m
Last Known Eruption: 1921
Largest Eruptive Volume: 50 km3

caldera Long Valley
Location: California
Volcano Type: Caldera
Summit Height: 3,390 m
Crater/Caldera Size: 17 x 32 km
Last Known Eruption: Pleistocene Era
Largest Eruptive Volume: 600 km3

caldera Valles Caldera
Location: New Mexico
Volcano Type: Caldera
Summit Height: 3,430 m
Crater/Caldera Size: 20 x 22 km
Last Known Eruption: Pleistocene Era
Largest Eruptive Volume: 600 km3

caldera Bruneau-Jarbridge
Location: Idaho
Volcano Type: Caldera
Summit Height: Not Applicable
Crater/Caldera Size: ~80 km
Last Known Eruption: Miocene Era
Largest Eruptive Volume: >1000 km3

caldera Yellowstone Caldera
Location: Wyoming
Volcano Type: Caldera
Summit Height: 2,805 m
Crater/Caldera Size: 45 x 85 km
Last Known Eruption: Late Pleistocene Era
Largest Eruptive Volume: >2000 km3

caldera La Garita
Location: Colorado
Volcano Type: Caldera
Summit Height: Not Applicable
Crater/Caldera Size: 35 x 75 km
Last Known Eruption: Oligocene Era
Largest Eruptive Volume: 5000 km3

Questions

1. The eruptive volume corresponds to the explosiveness of a volcano. Which volcano had the most explosive eruption? Which volcano had the least explosive eruption?

2. Does there seem to be a relationship between the size of a volcano's crater/caldera and an eruption's explosiveness? Why or why not?

After you answer these questions, mark the "Volcano Suspects Table" on your "CSI: Ashfall Fossil Beds" handout with the volcano or volcanoes you feel is or are the least likely suspect(s) based on the data, and rate your confidence level in your answer.




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