基于图像信息方法的日本东北MW9.0地震回溯性预测研究

以日本局部地区(32.0°~46.0°N, 136.0°~148.0°E)为研究区域, 应用图像信息方法, 选用8 a滑动预测窗长, 1°×1°网格为主要计算参数, 系统计算了研究区域内2000年以来的“地震热点”(显著异常地区)并获得了区域内7级以上大震特别是2011年日本东北M_W9.0地震的热点演化图像。 结果表明: ① 包含M_W9.0地震的预测时间窗内, 其震中的邻近网格持续有热点出现, 并且其中有4个连续滑动的窗口中该地震震中所在网格亦存在热点。 ② 在回溯时间段内发生的21个M≥7.0地震中, 除2004年9月5日发生于日本近畿南岸近海的M7.1地震前无地震热点外, 绝大多数在震前皆有热点出现。 ③ 与其他M≥7.0地震相比, M_W9.0地震前热点图像分布范围更广, 稳定性更好, 持续时间更长。

Retrospective Forecasting Study of the Tohoku MW9.0 Earthquake by Pattern Informatics Method

In this paper, Pattern Informatics (PI) method was applied to the retrospective forecast study for M≥7.0 earthquakes, especially the Tohoku M_W9.0 earthquake in the chosen local area (32.0°~46.0°N, 136.0°~148.0°E) in Japan. With calculating parameters of 1°× l° grid and forecasting window of 8 years, hotspot diagrams of each forecasting window have been obtained since the year of 2000,and the relationship between the hotspots and all the M≥7.0 earthquakes during the forecasting windows were studied,especially for the M_W9.0 Tohoku earthquake in 2011. The results show that: ① In all forecasting windows containing the M_W9.0 Tohoku earthquake,the hotspots were in its Moore neighborhood grids. And in four continuous sliding windows,hotspot appeared in its epicentral grid. ② Totally,twenty-one M≥7.0 earthquakes occurred in the retrospective forecasting windows,and most of them occurred in the hotspot grid or its Moore neighborhood grids. Only the M7.1 earthquake off the coast of Japan Kinki on Sep.5^th 2004 did not occurred in the hotspot grid or its Moore neighborhood grids. ③ Compared with other M≥7.0 earthquakes,hotspots about M_W9.0 Tohoku earthquake has wider distribution zone,longer lasting time,and higher stability.