Kknight
May 1st, 2008, 12:50 PM
The thread about 'The Big One' in Oregon had to be deleted because of the site it linked to. I found the article from an actual news site, so I'm re-posting it...hope that's OK:
Official earthquake hazard maps that influence building codes and insurance rates now recognize what many scientists have already concluded: That a major earthquake off the Oregon Coast could be not just bad, but really, really bad.
The new national seismic hazard maps released by the U.S. Geological Survey this week now reflect the increasing belief that the Cascadia Subduction Zone offshore is likely to rupture all at once, in an earthquake close to magnitude 9, probably followed by a tsunami.
Scientists now identify that as more likely than an alternate scenario where sections of the subduction zone snap individually, triggering less intense earthquakes closer to magnitude 8.
A magnitude 9 earthquake would be similar to the one that produced a deadly tsunami in the Indian Ocean in 2004. The last such earthquake in the Pacific Northwest occurred in 1700 and is believed to have been close to magnitude 9.
Previously scientists figured there was a roughly equal probability of either size earthquake along the subduction zone, where one plate of the Earth's crust slides beneath another. This time they assigned a two-thirds chance that a subduction zone quake, if it occurs, would hit magnitude 8.8 to 9.2.
http://www.oregonlive.com/environment/oregonian/index.ssf?/base/news/1209095709269010.xml&coll=7
Official earthquake hazard maps that influence building codes and insurance rates now recognize what many scientists have already concluded: That a major earthquake off the Oregon Coast could be not just bad, but really, really bad.
The new national seismic hazard maps released by the U.S. Geological Survey this week now reflect the increasing belief that the Cascadia Subduction Zone offshore is likely to rupture all at once, in an earthquake close to magnitude 9, probably followed by a tsunami.
Scientists now identify that as more likely than an alternate scenario where sections of the subduction zone snap individually, triggering less intense earthquakes closer to magnitude 8.
A magnitude 9 earthquake would be similar to the one that produced a deadly tsunami in the Indian Ocean in 2004. The last such earthquake in the Pacific Northwest occurred in 1700 and is believed to have been close to magnitude 9.
Previously scientists figured there was a roughly equal probability of either size earthquake along the subduction zone, where one plate of the Earth's crust slides beneath another. This time they assigned a two-thirds chance that a subduction zone quake, if it occurs, would hit magnitude 8.8 to 9.2.
http://www.oregonlive.com/environment/oregonian/index.ssf?/base/news/1209095709269010.xml&coll=7