Seamless Map of Depth to the Moho Interface in the Afro-Arabian Region Using Gravity Data Derived From EGM2008

Abstract

The Afro-Arabian region is one of the few places on land, where rifting processes at divergent plate boundaries can be thoroughly investigated. One of the crucial factors in understanding rifting processes involves assessing the crustal thickness. In this study, gravity data from the Earth Gravitational Model 2008 is used to create a seamless map of the depth to the Moho interface. Unlike many previous investigations that focused on specific localized areas, within the region, results from the current study provide a comprehensive view. The depth obtained from the current investigation aligns well with findings from earlier studies, exhibiting a bias of 0.69 km and a standard deviation of 3.89 km. Within the region, maximum and minimum depths to the Moho interface are observed beneath the northwest Ethiopian Plateau and the Gulf of Aden Rift (GAR), respectively. Analyzing profiles across the Red Sea, Main Ethiopian, and GARs, the study concluded that the Southern Main Ethiopian Rift is in an earlier stage of the rifting process, while the GAR is at an advanced stage. Furthermore, the interpretation of the current findings led to the inference that there might exist two potential plume tails driving the rifting process in the East Africa Rift—one originating from the Afar region and the other from South Kenya. This inference primarily relies on the isostatic compensation stages observed in the various rift systems throughout the region.