Estimation of source model for damaging earthquake occurring beneath Kanto area based on high-accurate simulation of wide-area intensity pattern

据悉，由于菲律宾海板块和太平洋板块俯冲到北美板块之下，东京地区经常发生大地震。最近发生在东京地下的破坏性地震是1855年的安sei江户地震，1894年的明治东京地震和1923年的关东地震。众所周知，关东地震发生在菲律宾海板块俯冲的顶部，而其他地震被认为发生在东京湾，但震源深度未知。许多研究者试图通过分析关东地区的地震烈度分布格局来确定这些地震的震源机制，但东京中心地区的地震烈度格局将受到浅层局部结构的场地放大效应的影响，而不是与震源本身直接相关。本文总结了强地震动的特征和地震造成的破坏。然后，我们用东京以下的非均质地壳和上地幔结构模型与最近发生在东京的地震和相应的计算机模拟对比了局地和区域尺度的强度模式，找到了安世江户和明治东京地震的可参考震源模式。

The Tokyo metropolitan area is known to have been struck with large earthquakes due to the subduction of Philippine Sea Plate and Pacific Plate beneath the North American plate. The recent damaging earthquakes that occurred beneath Tokyo were the 1855 Ansei Edo earthquake, the 1894 Meiji Tokyo earthquake and the 1923 Kanto earthquake. Whereas the Kanto earthquake is known to have occurred at the top of the subducting Philippine Sea Plate, the other events are considered to have occurred in Tokyo bay but their source depths are unknown. Many researchers have attempted to determine the source mechanisms of these earthquakes through analysis of the pattern of seismic intensity distribution in the Kanto area, but the intensity pattern in the center of Tokyo would be considerably affected by the site amplification effect of the shallow, localized structure rather than be related directly to the source itself. In the present paper, we summarize the characteristics of strong ground motions and damage caused by the earthquakes. We then compare the pattern of intensity in local and regional scale with those of recent earthquakes occurring in Tokyo and corresponding computer simulations using heterogeneous crust and upper-mantle structure models below Tokyo to find referable source models for the Ansei Edo and Meiji Tokyo earthquake.