Before M9.0 Earthquake of 2011 in Japan
On March 11, 2011, an M9.0 earthquake was set off under the Pacific Ocean between Honsyu Island and the Japan trench.
Recently Japanese scientists found that this March 11 earthquake was an indirect product of another earthquake.
On March 9, 2011, two days before March 11, an M7.3 earthquake occurred near the epicenter of the M9.0 earthquake. It caused slow sliding of a great mass of undersea land toward the Japanese trench.
http://www.ab.cyberhome.ne.jp/~catfish/event/2011tohokuoki.html
In the above figure, the brown lines, including the Japanese trench along with the straight line A to B, are boundaries between continental plates. Note that 2011/03/11 05:46 means March 11, 2011 at 2:46 p.m. (Japan Time). M9.1 was later corrected to Magnitude 9.0.
So, if earthquake seismology had been more advanced on March 9, 2011, scientists should have been able to catch a sign that a huge but slow undersea land slip was triggered. They must have been able to predict another big earthquake coming soon. Then, many lives must have been saved and the nuclear accident might have been avoided.
