In Iwate Prefecture, where protective walls 10 meters were built, residents have thought beyond the reach of the tsunami.
To improve the estimates and alerts, you must base calculations on a larger volume of data, Hiroo Kanamori believes. In this case, the Japanese agency had information from seismometers short period which should have been added seismometers long period, the two recording seismic waves of different nature. The technology exists, it is better to use it, concludes the researcher.
Great earthquakes always surprising
Unlike volcanoes, whose signs are well-interpreted an impending earthquake predictions always escapes. Seismologists determine the areas where we can expect earthquakes. But again, its not so simple: the earthquake of March 11, called Tohoku-Oki earthquake in Japan, is not the first earthquake of strong magnitude to thwart the theoretical predictions. In April 2007 the 8.1 magnitude earthquake in the Solomon Islands occurred on a zone where oceanic crust is formed and where we did not expect such a break, says the American geologist Thorne Lay in the journal Nature.