Walvis Ridge Passive-Source Seismic Experiment - Seismic structures and seismotectonics in the passive continental margin of NW Namibia

纳米比亚北方的Etendeka大陆泛滥玄武岩区由沃尔维斯海岭与特里斯坦-库尼亚热点相连，在全球板块构造概念中具有重要意义，是了解南大西洋解体期间地幔柱-岩石圈相互作用的理想场所。我们建议在沃尔维斯海脊与纳米比亚北方大陆边缘相交的位置建立一个两栖被动震源地震网络。宽带地震台网将由20个三分量陆地台站和12个海底台站组成，运行时间为1-1.5年。加上在Tsumeb的一个永久台站和以前地震实验的数据，我们将有38个陆上/海上台站，覆盖面积约为400公里x800公里。这种台站配置将使我们能够绘制纳米比亚北方被动大陆边缘之下海洋-大陆过渡区的岩石圈和更深的上地幔结构图，并发现与假设的热点轨迹有关的地震异常，该热点轨迹沿沃尔维斯海岭沿着从大陆到海洋。所获得的数据也可用于研究非洲超级地幔柱引起的地幔下部速度异常。这一建议是第一次尝试映射一个经典的羽/洪水玄武岩省与现有的地球物理方法，以解开在下地壳和地幔岩石圈断裂的影响。新的地震数据将为SPP计划内的多学科综合和结果整合提供基础。

The Etendeka continental flood-basalt province in northern Namibia, linked by the Walvis Ridge to the Tristan da Cunha hotspot, has a great importance in global plate tectonic concepts, and is an ideal place to understand the roll of the plume-lithosphere interaction during break-up of the Southern Atlantic Ocean. We propose to operate an amphibian passive-source seismic network at the position, where the Walvis Ridge intersects with the continental margin of northern Namibia. The broadband seismic network will be composed of 20 three-component land stations and 12 ocean-bottom stations, and will be operated for 1-1.5 year. Together with a permanent station in Tsumeb and data from a previous seismic experiment, we are going to have 38 on-/off-shore stations covering an area of approximately 400 km x 800 km. This configuration of stations will allow us to map the lithospheric and deeper upper mantle structure in the ocean-continent transition beneath the passive continental margin of northern Namibia and to find seismic anomalies related to the postulated hotspot track from the continent to the ocean along the Walvis Ridge. The acquired data can also be used to study the velocity anomaly in the lowermost mantle caused by the Africa super plume. This proposal is part of the first attempt to map a classical plume/flood basalt province with the existing geophysical methods to unravel the impact of the break-up in the lower crust and mantle lithosphere. The new seismic data will provide the basis for multi-disciplinary synthesis and integration of results within this SPP program.