Featured Story

Mangroves move inland as seas rise

Adapting to the damaging effects of climate change, plants are gradually moving to where temperatures are cooler, rainfall is greater, f...


Next Big Quake: 'Locked and Loaded'

Disaster Preparadness: Alaska, USA
March 22, 2007
Click Map to Enlarge
One lesson we should take away from the Sumatra-Andaman earthquake is that every subduction zone is potentially locked, loaded, and dangerous." With an immense tectonic collision grinding away only 20 miles beneath the Alaska's southern rim, there is also a lesson for the Far North. Be ready, Alaskans. Be very ready. "We should not rule out completely another M9 (earthquake) in the not-so distant future. We don't know the repeat time and the variability in that time." The colossal collision between tectonic plates has shattered Alaska into a maze of over-riding cracks and strike-slipping faults. Each week, 150 to 200 quakes large and small are located in Alaska. The state remains one of the world hotspots for earthquakes, with as much as one-third of all the earthquake energy of the entire globe rumbling through local bedrock. Anchorage is five times more likely to have a major earthquake than San Francisco, and eight times more likely than Los Angeles. Alaska, in general, has five times more earthquakes than California. The last really large quake to hit Alaska came on Nov. 3, 2002: the magnitude 7.9 Denali Earthquake. It was the biggest slip-strike earthquake in North America in almost two centuries. The quake ruptured 210 miles across the Alaska Range, producing more change in the landscape in 100 seconds than would occur during 1,000 years of slow geologic slip. The rupture unzipped glaciers, opened deep chasms in ice, buried glaciers with millions of cubic yards of rock, creased mountain ranges with visible lines, twisted individual trees into shreds. The ground shifted up to 28 feet near the small village of Mentasta Lake in eastern Alaska and rose as much as 12 feet. But that quake, while causing more than $20 million in damage (but no serious injuries), was a baby compared to Alaska's Big One on March 27, 1964
Share this article
Copyright © 2018 Great Red Comet-Earth Science Chronicles • All Rights Reserved.
Template Design by BTDesigner • Powered by Blogger
back to top