Old Project Avalon Forum (ARCHIVE) - View Single Post - Scientists watch unusual Yellowstone quake swarm

Dantheman62 · 12-30-2008, 10:28 PM

Historically, four types of volcanic events have taken place in Yellowstone (you may click on each one to learn more):

1. Caldera Forming Eruptions -- 2.1 and 1.3 million years ago
2. Lava Flows -- about 30 between 640,000 and 70,000 years ago
3. Earthquakes -- 1000 to 3000 yearly; last notable quake was in 1959
4. Hydrothermal (Steam) Explosions -- small explosions in the 20th century; a
dozen or so major explosions between 14,000 and 3,000 years ago

12-30-2008, 10:28 PM	#11
Dantheman62 Avalon Senior Member Join Date: Sep 2008 Location: So. Cal. U.S. Posts: 4,205	Re: Scientists watch unusual Yellowstone quake swarm Historically, four types of volcanic events have taken place in Yellowstone (you may click on each one to learn more): 1. Caldera Forming Eruptions -- 2.1 and 1.3 million years ago 2. Lava Flows -- about 30 between 640,000 and 70,000 years ago 3. Earthquakes -- 1000 to 3000 yearly; last notable quake was in 1959 4. Hydrothermal (Steam) Explosions -- small explosions in the 20th century; a dozen or so major explosions between 14,000 and 3,000 years ago