Passive electromagnetic and seismological measurements to study deep partial melt structure beneath the Mid Atlantic Ridge (MAR)

被动电磁和地震测量研究大西洋中脊 (MAR) 下方的深层部分熔融结构

• 批准号: 5414850
• 负责人: Professor Dr. Torsten Dahm
• 金额: --
• 依托单位: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2003
• 资助国家: 德国
• 起止时间: 2002-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5414850?language=en
• 关键词: Passive; electromagnetic; seismological; measurements; study

Midocean spreading axes and divergent oceanic plate boundaries play a major geological, geochemical and biological role for the evolution of the oceanic crust and the oceanic system in general, as outlined in the call for proposals of the SPP 1144. Our research proposal has the goal to resolve regions of an anomalously low shear velocity, seismic attenuation and electrical resistivity beneath the midatlantic spreading axis within the study region of the SPP 1144. Such regions are indicative for the presence of partial melt with varying melt connectivity. We propose a joint marine electromagnetic and seismological experiment along the same profiles. The joint analysis and interpretation of such data will allow us to resolve the two- and three-dimensional structure of regions containing partial melt and melt lenses within the crust or at the crust-mantle boundary. Our study will thus provide elementary information on where and how fluids, magma and heat is transported from the mantle to the seafloor and spreading axis. We plan the seafloor experiment for the period beginning with autumn 2005 (second period of SPP 1144) and in cooperation with other groups of the SPP 1144. However, the development, preparation and calibration of own measuring systems has to start already now, as well as the development and improvement of our analysis techniques.

洋中伸展轴和洋板块边界的发散对海洋地壳和整个海洋系统的演化起着重要的地质、地球化学和生物作用，spp1144的方案征集中概述了这一点。我们的研究计划的目标是解决spp1144研究区域内大西洋中部扩展轴下的异常低剪切速度，地震衰减和电阻率区域。这些区域表明存在部分熔体，但熔体连通性不同。我们建议沿同一剖面进行海洋电磁和地震联合实验。对这些数据的联合分析和解释将使我们能够解决地壳内或壳幔边界包含部分熔融和熔融透镜的区域的二维和三维结构。因此，我们的研究将提供关于流体、岩浆和热量在何处以及如何从地幔输送到海底和传播轴的基本信息。我们计划在2005年秋季开始进行海底实验（spp1144的第二期），并与spp1144的其他小组合作。然而，开发、准备和校准自己的测量系统，以及开发和改进我们的分析技术，现在已经开始。