Discovery of a Massive Ancient Tectonic Slab in the Southeastern Indian Ocean:Implications for the Indian Ocean Geoid Low

A surprising discovery of a massive, ancient, subducted tectonic slab in the southeastern Indian Ocean, known as the southeast Indian slab (SEIS), encompassing the entire mantle down to the earth's core raises a whole set of new questions, and offers opportunities to answer some previously outstanding ones. Evidence for SEIS comes from a high-resolution tomographic study by Simmons et al.