Japan quake Hits America Growth

Japan quake Hits America Growth: A magnitude 6.7 earthquake rocked Japan today, the 75th aftershock of at least magnitude 6.0 from the devastating magnitude 9.0 quake on Mar 11, according to the America. Geological Survey (USGS). The earthquake data is preliminary and subject to revision. Japan has been rocked by hundreds of aftershocks since the deadly Tohoku earthquake, the greatest in Japan's recorded history. The aftershocks have been so plentiful that the global premier earthquake-measurement service has since modified its alert system to filter out the smaller aftershocks. The largest aftershock was a magnitude 7.9 quakes that struck less than an hour later the main shock. A magnitude 7.7 also struck that day. A magnitude 7.1 aftershock struck on Apr 7. [When Will the Aftershocks in Japan End?] The number of aftershocks appears staggering, but geologists are not surprised, especially for such big main shock. The rule of thumb for aftershock strength is that the greatest aftershock will be about one magnitude smaller than the main shock. The latest aftershock struck about fifty-four miles (eighty-eight kilometers) east of Honshu. The quake ruptured twenty miles (32 km) below the Earth's surface. Since the main quake off Japan's northeastern coast, hundreds aftershocks have shaken the island of Honshu, Japan's biggest and house to 100 million folks. Today's aftershock was caused by thrust faulting near the Japan Trench, the boundary between the Pacific and North U.S. tectonic plates (the huge, moving slabs of the Earth's crust). Thrust faulting happens when one tectonic plate dives under another. In this case, the Pacific plate is driving under the North U.S.A. plate. Earlier the magnitude 9.0 earthquakes, only nine magnitude 7.0 or bigger earthquakes had ruptured in this subduction zone since 1973.Japan quake Hits America Growth