Collaborative Research: Post-seismic response updip of the Chilean megathrust earthquake of February 27, 2010

在大地震引发的灾害中，大地震的直接影响就是明证，去年发生在日本附近的S毁灭性地震，以及海啸的局部和远程影响。尽管它们对人口稠密地区的生命和财产构成了巨大的风险，但这两种现象都还没有得到很好的理解。智利最近发生的大地震没有引发大海啸，可能是因为破裂造成了海底的表面破裂。现有证据表明，在距离海沟向下倾斜约30公里的浅层，没有发生滑动。因此，该项目的支持者推断，位于智利海岸破裂带上方的外部吸积楔体表现为一种多孔弹性介质，随着时间的推移，它将根据地震造成的新的应力状态进行调整。该提议的目的是通过部署配备流量计的海底地震仪聚焦阵列来观察这种瞬时调整的影响。这一努力的主要更广泛影响是大大提高了对巨型断裂、地震和海啸的认识。

Among the hazards that arise from large earthquakes are the direct effects of great earthquakes, as evidenced by last year?s devastating earthquake off Japan, and local and distant effects of tsunamis. Though they pose enormous risks to life and property in highly populated areas, neither of these phenomena is as yet well understood. The recent great earthquake in Chile did not generate a large tsunami, probably because the rupture produce a surface break at the seafloor. Available evidence suggests that slip did not occur at depths shallower than about 30 km down-dip from the trench. Accordingly, the proponents of this project infer that the outer accretionary wedge that lies along the Chile coast above the rupture zone behaves as a poro-elastic medium that will adjust over time to the new stress regime caused by the earthquake. The aim of the proposal is to observe the effects of this transient adjustment, by deploying a focused array of ocean bottom seismographs equipped with flow meters. The principal broader impact of this effort is considerably improved understanding of megathrust earthquakes and tsunamis.