To help us understand earthquakes after the big one in Japan, Smithsonian has republished an article about how scientists study earthquakes of the past to predict and prepare for future quakes. Past disasters left clues behind, like dead cedar trees in Washington state.
Although earthquakes still cannot be predicted accurately, the body of data is growing that may lead to better forecasts. Link
(Image credit: Brian Smale)
In one of the more remarkable feats of modern geoscience, researchers have pinpointed the date, hour and size of the cataclysm that killed these cedars. In Japan, officials had recorded an “orphan” tsunami—unconnected with any felt earthquake— with waves up to ten feet high along 600 miles of the Honshu coast at midnight, January 27, 1700. Several years ago, Japanese researchers, by estimating the tsunami’s speed, path and other properties, concluded that it was triggered by a magnitude 9 earthquake that warped the seafloor off the Washington coast at 9 p.m. Pacific Standard Time on January 26, 1700. To confirm it, U.S. researchers found a few old trees of known age that had survived the earthquake and compared their tree rings with the rings of the ghost forest cedars. The trees had indeed died just before the growing season of 1700.
Although earthquakes still cannot be predicted accurately, the body of data is growing that may lead to better forecasts. Link
(Image credit: Brian Smale)