The Indian Ocean Geoid Low at a plume-slab overpass

The Indian Ocean Geoid Low (IOGL) appears as a prominent feature if the geoid is, usual, shown with respect to Earth's reference shape. However, it is relative hydrostatic equilibrium, i.e. including excess flattening, merely regional low on north-south trending belt of geoid. For mantle viscosity structure an increase 2–3 orders magnitude from asthenosphere lower mantle, which suitable explain long-wavelength geoid, can result both negative density anomalies in upper and positive mantle. Here we propose that IOGL be explained due linear, approximately north-south-trending high-density anomaly crossed by West-Southwest–East-Northeast low-density While former its location region subduction inbetween two Large Shear Velocity Provinces (LLSVPs), here latter eastward outflow Kenya plume rising above eastern edge African LLSVP. We show that, realistic assumptions match size, shape low.