Hazards & Disasters Environmental Monitoring Environmental Futures Geology
Source: U.S. Geological Survey.Published: March 14, 2011, 12:00 am| Topics: | Hazards & Disasters Environmental Monitoring Environmental Futures Geology |
There's a 100 percent chance of an earthquake today. Though millions of persons may never experience an earthquake, they are very common occurrences on this planet. So today -- somewhere -- an earthquake will occur.
It may be so light that only sensitive instruments will perceive its motion; it may shake houses, rattle windows, and displace small objects; or it may be sufficiently strong to cause property damage, death, and injury.
It is estimated that about 700 shocks each year have this capability when centered in a populated area. But fortunately, most of these potentially destructive earthquakes center in unpopulated areas far from civilization.
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World Seismicity Map. Source: USGS. Click for Larger Image.
Since a major portion of the world's earthquakes each year center around the rim of the Pacific Ocean (Ring of Fire), referred to by seismologists as the circum-Pacific belt, this is the most probable location for today's earthquake. But it could hit any location, because no region is entirely free of earthquakes.
Stating that an earthquake is going to occur today is not really "predicting earthquakes". To date, they cannot be predicted. But anyone, on any day, could make this statement and it would be true. This is because several million earthquakes occur annually; thereby, thousands occur each day, although most are too small to be located. The problem, however, is in pinpointing the area where a strong shock will center and when it will occur.
Earthquake prediction is a future possibility, though. Just as the Weather Bureau now predicts hurricanes, tornadoes, and other severe storms, the NEIC may one day issue forecasts on earthquakes. Earthquake research was stepped up after the Alaska shock in 1964. Today, research is being conducted by the USGS and other federal and state agencies, as well as universities and private institutions. Earthquake prediction may some day become a reality, but only after much more is learned about the earthquake mechanism.
[size=1.1em]U.S. Geological Survey (Content Source);Sidney Draggan Ph.D. (Topic Editor) "Chance of an Earthquake". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth March 14, 2011; Last revised Date March 16, 2011; Retrieved September 25, 2012 <http://www.eoearth.org/article/Chance_of_an_Earthquake>
for_undead 发表于 2012-9-25 19:48
地震在哪儿啊
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