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- THE WEEK, Page 20HEALTH & SCIENCEQuake Predictor
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- Changes in a geyser's timing may mean the earth is about to
- move
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- Geysers like Old Faithful fire fountains of steaming water
- from the earth at impressively regular intervals. When the
- intervals change, though, it may be time to stop being impressed
- and start running for cover. According to a report in Science,
- the interval between one geyser's eruptions, at least, tends to
- fluctuate before a major earthquake takes place. The only catch:
- the quakes happen far away.
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- The report is based on a study of a geyser near Calistoga,
- a town in Northern California's wine country noted for its hot
- springs. Two scientists, now at Washington's Carnegie
- Institution, analyzed the timing of eruptions from 1973 to 1991.
- They found that the schedule was disrupted one to three days
- before each of the three biggest earthquakes of the period in
- the region. Just before the devastating Loma Prieta quake that
- hit the San Francisco area during the 1989 World Series, for
- example, the time between eruptions jumped from 90 to 150
- minutes. Because the quakes occurred up to 250 km (155 miles)
- from the geyser, the data are not very helpful in warning the
- public, but they do support the idea that earthquakes result
- from underground stresses ranging over wide areas, not just
- along local faults.
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