Characterisation of the Tohoku subduction fault zone using downhole logging measurements and physical properties data taken on recovered core.

2011年日本沿海的东北地震（Mw 9.0）产生了巨大的滑动（约50米）。地震科学家没有预料到俯冲带这部分的巨大位移，并引发了毁灭性的海啸，夺走了2.3万人的生命，并在本州东北海岸造成了巨大的破坏。综合海洋钻探计划（IODP）第343远征队的主要科学目标是了解大滑动地震的物理机制，目前对这一机制的了解甚少。这是一个具有重大社会意义的主题，关于评估来自俯冲带的未来地震的剧烈震动和大海啸。2012年4月1日至5月24日期间，考察队将在日本近海进行钻探、取芯、测井，并在“地球号”（R/V Chikyu）部署钻孔观测站。该项目将结合现场收集的井下物理性质数据和回收的岩心测量数据，帮助精确定位断层带，描述遇到的地层特征，并研究区域应力状态。因此，它将直接有助于这次考察所确定的主要目标。

The 2011 Tohoku Earthquake (Mw 9.0) off the coast of Japan produced huge slip (~50 metres). The large displacement on this portion of the subduction zone was unexpected by earthquake scientists and produced a devastating tsunami that took over 23,000 lives and caused massive damage along the northeast coast of Honshu. The primary science objective of Integrated Ocean Drilling Program (IODP) Expedition 343 is to understand the physical mechanisms of large slip earthquakes, which at present, is poorly understood. It is a subject of great societal relevance regarding the evaluation of severe shaking and large tsunamis from future earthquakes originating at subduction zones.Between 1 April and 24 May 2012 the Expedition will be offshore Japan drilling, coring, logging and deploying borehole observatories from the R/V Chikyu. This project will use a combination of physical properties data collected in situ downhole and measurements on recovered core to: help precisely locate the fault zone, characterise the formations encountered, and investigate the regional stress regime. Hence, it will directly contribute to the major objectives set out by this expedition.