According to quakepredictor.net the Japan quake may not have been a normal event.
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Japanese authorities have canceled all tsunami warnings after a strong 7.1 magnitude earthquake shook the ocean floor east of Japan. The U.S. Geological Survey says the quake struck 326 kilometers off the coast, about 3 a.m. local time Saturday It was centered 10 kilometers below the ocean's surface. We were at level 63 at the time of this odd event..It did not have normal characteristics we would expect as measurements have not been very elevated today, nor have we seen any fall in pressure reading since the event as of this update.
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