US and Japanese Collaborative Research: A Magnetotelluric (MT) Transect Across the Mariana Subduction Factory

研究所将在马里亚纳岛弧上进行一次深度探测大地电磁实验，以量化整个俯冲系统、从海洋岩石圈到海沟、穿过岛弧并穿过弧后的电导率，以解决水释放到地幔楔中以及水合作用和弧后扩张导致的熔融过程的问题。这项研究是与日本同事合作进行的;美国的仪器将放置在马里亚纳以东的太平洋板块上，在弧前盆地和西马里亚纳海岭。这一海底断面将位于系统的中间，在那里，深层结构应最大限度地是二维的。该研究将测量整个系统从海底以下约20公里至200公里深处的二维电阻率剖面。该样带将与独立资助和动员的地震实验的样带重合，收集广角反射和折射数据，以及当地和非当地地震到达，以限制系统下方的地壳和地幔速度和衰减结构

The PIs will conduct a deep-probing magnetotelluric (MT) Experiment across the Mariana arc, to quantify the electrical conductivity across the subduction system, from oceanic lithosphere, into the trench, across the island-arc and through the back-arc, to address issues of water release into the mantle wedge and melting processes resulting from hydration and back-arc spreading. This study is in collaboration with Japanese colleagues; the US instruments will be placed on the Pacific plate to the east of the Mariana, in the fore-arc basin and across the West Mariana Ridge. This seafloor transect will be in the middle of the system where deep structure should be maximally two-dimensional. The study will measure a 2-D electrical resistivity section across the system from depths of about 20km to 200km below the seafloor. The transect will be coincident with that of the independently funded and mobilized seismic experiment, collecting wide-angle reflection and refraction data, as well as local and teleseismic earthquake arrivals to constrain crust and mantle velocity and attenuation structure beneath the system