Friday, May 20, 2005

SHAKY FOUNDATION

The San Andreas Fault, which snakes uncomfortably close to Los Angeles and other large cities along much of California's length, has been relatively quiet for the past 148 years.

This could end soon, scientists said today.

Researchers have calculated a 20 to 70 percent probability that southern California will be hit by a large earthquake in the next 30 years. The forecast is based on the frequency of past events.

Geologists stress, however, that earthquake prediction, in its infancy, is notoriously difficult. Forecasts tend to be very general, specifying a range of decades rather than years or weeks for possible activity.

The last really big quake to hit southern California was the Fort Tejon Earthquake of 1857, which was estimated to be around magnitude 8 from the 186 miles (300 kilometers) of rupture along the San Andreas.


Bet you wouldn't guess that California ranks only 10th on the list of the strongest earthquakes. So far Gov. Ahnold has done a good job keeping the earthquakes at bay.

Strongest US Earthquakes (source: USGS)

Rank Locale Size

1 Prince William Sound, AK 9.2
2 Andreanof Islands, AK 9.1
3 Rat Islands, AK 8.7
4 Shumagin Islands, AK 8.2
5 New Madrid, MO 8.1
6 Yakutat Bay, AK 8.0
7 Andreanof Islands, AK 8.0
8 New Madrid, MO 8.0
9 Cape Yakataga, AK 7.9
10 Fort Tejon, CA 7.9

1 comment:

Dude said...

No statistic screams INEXACT SCIENCE like a 20-70% chance of something happening within three decades. I could predict a 20-70% chance that science will produce a genetically-engineered pig with wings within 30 years. If it doesn't happen, no problem, it was running up to 80% against anyhow, so my data was good.

Isn't a spread of 50% the same as saying it is a coin flip? Maybe if it is 40-90% then it is more likely to happen than 50/50, but can you take anyone seriously who pins a 20-70% chance of something happening as actually holding a scientific opinion beyond pure guesswork?

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