A massive underwater landslide in the Krishna-Godavari (KG) basin, reaching depths of 950 meters to 1.1 kilometers below the ocean surface, has raised concerns about its potential to trigger a tsunami and disrupt critical infrastructure. The discovery was announced by the Goa-based National Institute of Oceanography (NIO), which described the landslide as one of the largest ever recorded in this part of the Bay of Bengal.
The landslide, which could have occurred between 2009 and 2015, displaced an estimated 11 cubic kilometers of sediment—enough to fill around 44 lakh Olympic-sized swimming pools. At some points, sediment deposits from the landslide are as thick as 60 meters, covering an area of approximately 70 square kilometers, equivalent to 10,000 football fields.
“The enormous displacement of sediments and water caused by this landslide poses a serious risk to underwater communication cables, oil rigs, and coastal communities,” NIO Director Sunil Kumar Singh told The Times of India. He added that such a disturbance could potentially generate a tsunami, emphasizing the need for monitoring and preparedness.
Causes and Consequences
The scientists suggest that several natural events may have contributed to the seabed collapse, including Cyclone Helen, a Category-1 storm that struck the region in November 2013. The cyclone’s intense winds and waves could have destabilized already weakened sediments on the ocean floor.
Additional contributing factors include extreme flooding in 2010 and 2013, as well as a 6.0-magnitude earthquake in May 2014 that shook the Bay of Bengal. Even minor events, such as heavy rainfall, smaller cyclones, or localized tremors, can amplify risks if sediment layers are fragile.
The landslide, known as a mass transport deposit (MTD), was detected using advanced ocean-floor mapping technology that tracks changes over time. NIO researchers highlighted that such large-scale underwater slope failures can severely impact critical underwater structures, such as communication cables and oil rigs, which are vital for global connectivity and energy production.
Call for Increased Monitoring
Given the risks associated with underwater landslides, scientists are urging for enhanced research and surveillance in the KG basin. “This discovery underscores the importance of monitoring and understanding underwater geological hazards, especially in regions prone to cyclones and earthquakes,” said NIO researchers.
As coastal populations grow and underwater infrastructure becomes increasingly critical, better preparedness and predictive models are essential to mitigate the risks posed by such events. Scientists hope the findings will drive further investigations into the stability of the seabed in vulnerable regions like the Bay of Bengal.