RHUM-RUM (Réunion Hotspot and Upper Mantle & Réunions Unterer Mantel): Seismological imaging of a mantle plume under La Réunion, western Indian Ocean

留尼汪岛是世界上最活跃、最长寿的火山之一。它的历史悠久，5500公里长的热点轨道出现在印度的德干陷阱中，印度是地球上最大的洪水玄武岩省份之一，当它们喷发时，对全球气候和生活产生了巨大影响。我们想要建立为这个强大的热点地区提供燃料已有6500万年之久的热源和“管道系统”：有没有一条管道通向地幔最深处(2900公里深)，由地球熔融的核心直接加热？这与中地幔深处的非洲超级水井有联系吗？或者，留尼汪岛的热点可能代表着一种肤浅得多的机制？Rhum-rum实验的目标是对从地表向下到核-地幔边界的地幔热柱或地幔热柱的缺失进行地震成像，并从物质和热流的角度了解结果。这包括羽流管道中的垂直上升流，以及任何向西印度洋上地幔扩散的侧向流。我们将调查长期存在的假设，即来自留尼汪岛的软流层通道在1500公里远的地方供给中印度海脊(“烟柱-海脊相互作用”)。朗姆酒是德法合作的酒。我们希望共同部署57个海底地震仪和27个陆地站，覆盖2000×2000平方公里的区域，使其成为迄今为止最大的海洋羽流成像项目。这些数据将使用地震学中最现代的基于波形的成像方法进行分析。

The island of La Réunion is one of the most active and long-lived volcanoes in the world. Its well-dated, 5500-km long hotspot track emerges from the Deccan Traps of India, one of the largest flood basalt provinces on earth, which had a massive impact on global climate and life when they erupted. We want to establish the heat source and "plumbing system" that has been fueling this powerful hotspot for 65 million years: Is there a conduit into the deepest mantle (2900 km deep), directly heated by earth's molten core? Is there a connection to the African Superswell at mid-mantle depths? Or could the Réunion hotspot represent a much shallower mechanism? The goal of the RHUM-RUM experiment is to seismically image a mantle plume - or lack of plume - from the surface down to the core-mantle boundary, and to understand the results in terms of material and heat flow. This comprises vertically ascending flow in the plume conduit, as well as any lateral flow spreading into the upper mantle of the western Indian Ocean. We will investigate the long-standing hypothesis that an asthenospheric channel from La Réunion feeds the Central Indian Ridge at 1500 km distance ("plume-ridge interaction"). RHUM-RUM is a German-French collaboration. Jointly we want to deploy 57 ocean-bottom seismometers and 27 land stations over an area of 2000 x 2000 km², making this the largest ocean plume imaging project to date. The data will be analyzed using the most modern, waveform-based imaging methods in seismology.