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附近的俯冲洋壳进行多道地震 (MCS) 调查，以支持该 Margins 计划研究区域的 SEIZE 和俯冲工厂目标。 主要目标是表征俯冲科科斯板块结构性质的变化，并尝试将这些变化与已知的火山弧化学分段联系起来，最好通过 Ba/La 等比率来显示，这些比率反映了俯冲带物质输入的相对变化。 MCS 勘测将得到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 条带测深、重力和磁学数据的补充。 这项拟议的研究是一项更大的国际努力的一部分，该研究使用了德国研究船 R/V Sonne。 MCS 和 Hydrosweep 调查将在 R/V Maurice Ewing 上使用其 6 公里长的拖缆进行。 R/V Sonne 将用于补给、部署和回收 OBH，而 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.******