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

Wiens 等人摘要这是沿东刘传播中心进行的主动和被动地震联合实验，旨在检验以下假设。 1. 地幔楔内的环流以板片驱动流为主。 2. 弧和弧后岩浆产生的相互作用通过影响熔体通量、岩石学和地球化学来控制洋脊的特征。 3. 地幔熔体供应的变化控制着脊顶特征，例如形态、热结构和热液喷发。被动实验由 55 台宽带海底地震仪和 5 台陆地地震仪组成，部署了 10 个月，以对熔体生产区的更大规模结构和地幔流动模式进行成像。主动震源实验由 100 台海底地震仪组成，沿传播中心 250 公里的一段部署，从膨胀的 Vala Fa 地区一直延伸到缺乏岩浆的东部 Lau 传播中心，那里没有轴向熔融透镜。从更广泛的角度来看，该实验解决了独特俯冲带环境中的山脊动力学的一阶问题，对于 R2K 计划的既定目标至关重要。研究生将得到所有四位 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.