The active Bengal lobe complex as the modern terminal sink of Earth’s largest submarine fan

Abstract The Bengal Fan, the world’s largest and among the few deep-sea fans still active today, has long been thought to have its active channel reaching the lower fan. Our findings reveal a middle-fan avulsion that shifted the terminal sediment sink 1,800 km landward, forming the modern terminal lobe complex. The lobes, dominated by sandy turbidites, are relatively thin (<20 m), but cover large areas (up to 1,350 km 2 ). Their evolution is strongly related to inherited topography and probably autogenic processes while external factors (e.g., monsoon and sea-level variation) control sediment supply and types of gravity flows. These lobes represent a small portion of the channel-levee-lobe system, as sediments mainly accumulated on the levees during Holocene highstand. Identifying the modern sink of the Bengal Fan provides a closure point for the Earth’s largest source-to-sink system, with implications for present-day fluxes of sediments, carbon, and marine litter across a vulnerable coastal region.