The Krishna Slide: A newly discovered massive submarine slide off the Eastern Indian Margin

Submarine mass-wasting processes significantly shape continental margins and represent major geohazards, such as tsunamis and damage to offshore infrastructure. Despite being a classic example of a passive margin, the Indian continental margin remains relatively understudied in terms of submarine mass-wasting processes compared to other global margins. This margin contains several petroliferous basins, with the Krishna-Godavari Basin being a key area for deep-water hydrocarbon exploration along the Eastern Indian Margin.
Recent high-resolution multibeam bathymetric data from the Krishna Basin have revealed, for the first time, the presence of a giant submarine slide. The headscarp lies about 10 km offshore, near the mouth of the Krishna River, which delivers a large sediment load to the margin. Morphometric analysis reveals a slide scar with a perimeter of approximately 60 km and a surface area of about 1,600 sq. km, making it one of the largest documented submarine slides along the Indian continental margin. The associated mass transport deposits (MTDs) extend over an area of ~5000 sq. km, reaching up to 160 km seaward from the scar, indicating a large-scale sediment remobilisation event.
The morphology of the slide scar and the widespread distribution of the MTDs suggest the occurrence of multiple landslide events following an initial megaslide. An integrated analysis of marine geophysical data and geological context indicates that several factors likely contributed to slope instability. These include the presence of gas hydrates, high sediment influx in the upper slope region from the Krishna River, regional fault systems, and neotectonic activities - all of which appear to be primary contributors to the megaslide. Additionally, recent studies propose that intense cyclonic activity in the Bay of Bengal may also act as a trigger for recurrent submarine slides, highlighting the complex interplay of geological and climatic influences in this region.