The world's largest submarine fan, located in the Bay of Bengal, is the Bengal Fan. It is also called the Ganges Fan, reflecting the enormous sediment contribution of the Ganges–Brahmaputra river system.
A submarine fan is a broad underwater deposit formed when sediment-laden turbidity currents flow from the continental shelf down submarine channels and spread across the deep ocean floor. The Bengal Fan formed largely from erosion of the Himalayas and Tibetan Plateau, uplifted by the collision of the Indian and Eurasian tectonic plates.
The fan stretches roughly 3,000 kilometres long and 1,430 kilometres wide, with sediment reaching a maximum thickness of about 16.5 kilometres. Its deposits cover much of the Bay of Bengal and include sediments millions of years old.
A common mix-up is the Indus Fan, which lies in the Arabian Sea and is also geologically important. The Bengal Fan is distinct because of its exceptional size and its connection to Himalayan erosion and the Ganges–Brahmaputra drainage system.