Fluid distribution around a seismogenic zone along a plate boundary fault imaged and monitored by controlled source electromagnetic sounding

在2005财政年度，我们进行了三项可行性研究和试验，以长期监测地震带。开发了海洋可控源电磁测量数值计算程序。在两次研究航行中进行了海洋直流电阻率调查。分析了苏门答腊大地震的余震记录。这些研究有助于海底电缆长期电磁仪和海底地震仪的新发展和完善。2006财政年度，在一个小水池中对这些海底仪器进行了水下测试。此外，位于东海大地震带的丰桥近海电缆通过电缆船被拉起，并在末端连接连接单元后被部署。在2007财政年度，新开发的海底仪器连接到丰桥电缆末端的连接单元。海底作业使用了JAMSTEC船舶和一艘潜水艇。因此，一个多学科的C ...更多信息 在丰桥附近，就在东海大地震带上，建造了一个以海底地震、地壳变形和海底地下水流动为目标的平板式观测台。丰桥近海电缆同时发送连续的人工电信号，从而开始了对海底以下电导率变化的首次海底监测。在连续海底监测之前，丰桥近海地区进行了海洋大地电磁测量，对东海特大地震带周围的地壳电导率结构进行了成像。12件器械成功展开并回收。所获得的数据集向我们展示了俯冲菲律宾海板块的导电性结构，因此，通过该项目提交了几篇论文和报告，涉及电缆观测站、海洋受控源电磁调查和海底地下水流可能激发的电磁现象。少

In FY 2005, we carried out three feasibility studies and tests for long term monitoring of seimogenic zone. A numerical calculation codes for marine controlled source electromagnetic survey was developed. Marine DC resistivity surveys were conducted at two research cruises. Seismic records of aftershocks of the Sumatra great earthquakes were analyzed. These studies are helpful for new development and refinement of cabled long-term ocean bottom electromagnetometers and ocean bottom seismometers. In FY 2006, underwater tests for these ocean bottom instruments were carried out in a small pool. Also, the off-Toyohashi cable, located on the Tokai mega-earthquake zone, was pulled up by using a cable ship and was deployed after attaching a junction unit to the end. In FY 2007, the newly developed ocean bottom instruments were connected to the junction unit at the end of off Toyohashi cable. The JAMSTEC vessels and a ROV were used for the seafloor operations. As a result, a multidisciplinary c … More abled observatory, whose targets are submarine earthquakes, crustal deformation and groundwater flow below the seafloor, was constructed off-Toyohashi, just on the Tokai mega-earthquake zone. Continuous artificial electric signals are sent from the off-Toyohashi cable simultaneously, so that the first ocean bottom monitoring of electrical conductivity variation below the seafloor was started.Before the continuous seafloor monitoring, marine magnetotelluric surveys were carried out off-Toyohashi area to image the crustal electrical conductivity structure around the Tokai mega-earthquake zone. Twelve instruments were deployed and recovered successfully. The obtained data set show us the conductivity structure of subducting Philippine Sea plate.As a result, several papers and presentations were presented through this project, relating to the cabled observatory, marine controlled source electromagnetic survey and electromagnetic phenomena possibly excited by groundwater flow below the seafloor. Less