The Ganga–Brahmaputra rivers contribute nearly 1000 million tons/yr of sediment. The sediment contributed from these two rivers forms the Bengal Delta and Submarine fan, a vast structure that extends from Bangladesh to the south of the Equator which is up to 16.5 km thick, and contains at least 1130 trillion tonnes of sediment accumulating over the last 17 million years at an average rate of 665 million tons/yr. The Bay of Bengal used to be deeper than the Mariana Trench, the present deepest ocean point.
The Ganga–Brahmaputra rivers contribute nearly 1000 million tons/yr of sediment The sediment contributed from these two rivers forms the Bengal Delta and Submarine fan a vast structure that extends from Bangladesh to the south of the Equator which is up to 165 km thick and contains at least 1130 trillion tonnes of sediment accumulating over the last 17 million years at an average rate of 665 million tons/yr The Bay of Bengal used to be deeper than the Mariana Trench the present deepest ocean point