Collaborative Research: Crustal Accretion and Mantle Processes Along the Subduction-Influenced Eastern Lau Spreading Center

摘要本文是沿东劳扩散中心进行的主动式和被动式相结合的地震实验，以检验以下假设。1. 地幔楔内的环流以板块驱动流为主。2. 弧和弧后岩浆生产的相互作用通过影响熔体通量、岩石学和地球化学来控制脊的特征。3. 地幔熔体的变化控制了山脊的形态、热结构和热液喷口等特征。被动式实验由55台宽带海底地震仪和5台陆地地震仪组成，部署时间为10个月，用于成像熔融产生区的大尺度结构和地幔流动模式。活源实验由100个海底地震仪组成，这些地震仪沿着扩张中心250公里的剖面部署，从膨胀的Vala Fa地区延伸到缺乏岩浆的东劳扩张中心北部，那里没有轴向熔融透镜。从更广泛的意义上说，这个实验解决了在一个独特的俯冲带环境下山脊动力学的一级问题，对R2K计划的既定目标至关重要。研究生将得到所有四个pi的支持。

Wiens et al.AbstractThis is a combined active and passive seismic experiment along the Eastern Lau Spreading Center to test the following hypotheses. 1. Circulation in the mantle wedge is dominated by slab driven flow. 2. Interaction of the arc and backarc magma production controls the character of the ridge by influencing melt flux, petrology, and geochemistry. 3. Variations in the mantle melt supply control ridge crest features such as morphology, thermal structure, and hydrothermal venting. The passive experiment consists of 55 broadband ocean bottom seismographs and five land seismographs deployed for 10 months to image the larger-scale structure of the melt production region and the mantle flow pattern. The active source experiment consists of 100 ocean bottom seismographs deployed along a 250 km section of the spreading center extending from the inflated Vala Fa region to the magma-starved northern Eastern Lau Spreading Center where the axial melt lens is absent.In broader terms this experiment addresses a first order problem in ridge dynamics in a unique subduction zone setting and is essential for the stated goals of R2K program. Graduate students will be supported by all four PIs.