Collaborative Research: Structure of the Nicaragua/Costa Rica Subduction Zone: A Framework for the Subduction Factory and Seismogenic Zone Initiatives

Silver99-09859推荐项目是对尼加拉瓜和哥斯达黎加海岸外的俯冲洋壳进行多通道地震（MCS）调查，以支持该边缘计划研究区域的SEIZE和Subduction Factory目标。研究的主要目的是描述Cocos板块俯冲构造性质的变化特征，并试图将这些变化与已知的火山弧化学分割联系起来，最能说明这一点的是Ba/La比值，它反映了进入俯冲带的物质的相对变化。MCS调查将辅以三条广角海底水听器（OBH）折射线，两条垂直于海沟，一条平行于海沟，以及Hydrosweep swath测深、重力和磁力数据。这项拟议的研究是一个更大的国际努力的一部分，使用德国研究船R/V Sonne。MCS和Hydrosweep测量将在R/V Maurice Ewing上进行，使用其6公里长的拖缆。R/V Sonne将用于提供、部署和回收OBH， OBH本身将由GEOMAR.******提供

Silver99-09859 Recommended Project is for a multichannel seismic (MCS) survey of the subducting ocean crust off the coasts of Nicaragua and Costa Rica in support of both SEIZE and Subduction Factory objectives in this Margins program study area. The primary objective is to characterize the changing structural nature of the subducting Cocos plate, and to try to relate these changes to known chemical segmentation of the volcanic arc, best shown by ratios such as Ba/La that reflect relative changes in material input into the subduction zone. The MCS survey will be supplemented by three wide-angle, ocean bottom hydrophone (OBH) refraction lines, two perpendicular and one parallel to the trench, as well as by Hydrosweep swath bathymmetry, gravity, and magnetics data. This proposed study is part of a larger, international effort, using the German research vessel R/V Sonne. The MCS and Hydrosweep surveys would be conducted aboard the R/V Maurice Ewing, using its 6 km-long streamer. The R/V Sonne will be used to supply, deploy and recover the OBH's, which will themselves be supplied by GEOMAR.******