RAPID Response to Tohoku Earthquake: Participation in Marine Geophysical Surveys of the Quake Rupture Zone

我们计划在2011年夏季参加一次或两次海洋地球物理调查，覆盖2011年3月日本本州岛东北大地震的破裂带。为了应对这次大地震，日本海洋地球科学技术机构（JAMSTEC）的地球演化研究所（IFREE）开展了一项海洋地球物理调查计划，试图探测与地震有关的海底和地下结构。s破裂。其中一次航行将包括在6月至7月开放式海底系统恢复和重新部署期间进行多波束测深测绘。计划于8月进行更广泛的监控监调查。加上广泛的陆上地震仪和全球定位系统网络，海上数据集为研究大地震期间与破裂有关的变形提供了前所未有的机会。摩尔和他的学生已被邀请参加海上帮助数据采集和船上数据处理，并参与结构解释和合成的海上数据集。参与巡航的主要优势是我们还可以参与数据分析阶段。我们将能够将新的数据集与IFREE以前收集的地震反射和测深数据联合收割机结合起来。在地震破裂带收集的地震反射数据将用作向IODP提出的东北近海快速反应钻探建议的现场调查。地震数据对于确定钻探目标至关重要。我们注意到，该地区较老的地震线虽然非常适合解释区域构造，但并没有对任何潜在的钻探地点进行成像，因此在任何钻探之前都需要高质量的图像。这项工作需要迅速获得资金的主要原因是，无论我们是否能够参加，日本人都将按计划开展工作。如果我们必须通过？标准？由于下一个提案截止日期是8月，因此在可以做出资助决定时，工作已经完成。因此，我们将失去美国科学家以相对较低的成本抢先体验这一大型数据集的机会。更广泛的影响这个项目的一个产品将是地震反射和多波束测深数据集，这将有助于描述地球的特征。这是有史以来最好的大地震。虽然这一数据集将存在于日本国内，但它不会在数月（或数年）内向非日本研究人员发布。我们的参与将确保美国科学家能够帮助解释数据。地震反射数据将用作现场勘测，以确定快速响应钻井计划是否具有合适的钻井目标。该项目还将为两名研究生提供宝贵的航海经验。

We propose to participate in one or two marine geophysical surveys covering the rupture zone of the March 2011 great earthquake off Tohoku, Honshu, Japan during summer, 2011. In response to this great earthquake, the Institute For Research on Earth Evolution (IFREE) of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has undertaken a program of marine geophysical surveys to try to detect seafloor and subsurface structures associated with the quake?s rupture. One cruise will include multibeam bathymetric mapping during OBS recovery and redeployment in June-July. A more extensive MCS survey is planned for August. Coupled with the extensive on-land seismograph and GPS network, the offshore data set presents an unprecedented opportunity to study deformation associated with rupture during a great earthquake. Moore and his students have been invited to participate in the offshore to help with data acquisition and on-board data processing and to participate in the structural interpretation and synthesis of the offshore data sets. The main advantage of participating in the cruises is that we will also be able to participate in the data analysis phase. We will be able to combine the new data sets with seismic reflection and bathymetric data collected previously by IFREE. The seismic reflection data to be collected in the earthquake rupture zone will be used as a site survey for a proposal to IODP for Rapid Response Drilling off Tohoku. The seismic data will be essential for defining drilling targets. We note that the older seismic lines in this area, while excellent for interpreting the regional tectonics, do not image any potential drill sites, so high-quality images will be required in advance of any drilling. The main reason why this work needs to be funded quickly is because the Japanese will be carrying out the work as already scheduled, whether or not we are able to participate. If we have to go through the ?standard? proposal process, with the next proposal deadline being in August, the work will have already been completed by the time funding decisions could be made. We would thus lose out on this opportunity for U.S. scientists to have early access to this large data set at relatively low cost.Broader impactsOne product of this project will be a seismic reflection and multibeam bathymetry data set that will help characterize the Earth?s best documented great earthquake. Although this data set will exist within Japan, it will not be released to non-Japanese researchers for many months (or years). Our participation will ensure that US scientists will be able to help interpret the data. The seismic reflection data will be used as a site survey to determine whether or not a rapid-response drilling program will have suitable drill targets. This project will also provide valuable sea-going experience for two graduate students.