The Indian Ocean harbors a colossal and enigmatic phenomenon known as the “Gravity Hole,” which scientists now suspect may be the remnants of an ancient sea that vanished millions of years ago, according to a recent study.
This groundbreaking research offers a possible explanation for the origins of the Earth’s most remarkable gravity anomaly, an immense depression hidden beneath the ocean’s surface. Known as the Indian Ocean geoid low (IOGL), this vast expanse spans over 2 million square miles and lies more than 600 miles beneath the Earth’s crust.
The study, published in Geophysical Research Letters, proposes that the IOGL comprises slabs from the Tethys Ocean, a long-lost sea that plunged into the depths of the planet millions of years ago. The Tethys Ocean, which once separated the supercontinents of Gondwana and Laurasia, is believed to have perturbed the African Large Low Shear Velocity province, also known as the “African blob,” generating plumes beneath the Indian Ocean.
Lead author Debanjan Pal and Attreyee Ghosh explain, “These plumes, along with the mantle structure in the vicinity of the geoid low, are responsible for the formation of this negative geoid anomaly.”
Previous studies on the gravity anomaly focused solely on its present-day state, without delving into its origins. However, this new research utilized over a dozen computer models to provide insights into the ancient forces that shaped the IOGL.
Geophysicist Shijie Zhong expressed his fascination with this unique phenomenon, stating, “We like to talk about the positive gravity anomalies, such as the superplumes over Africa and the Pacific. But the geoid low in the Indian Ocean is one of the most profound gravitational anomalies on our planet.”
The Gravity Hole is estimated to have assumed its current form around 20 million years ago and is predicted to endure for millions more. Its intriguing nature has captivated scientists, shedding light on the geological history of the Indian Ocean and deepening our understanding of the complex forces at work beneath our planet’s surface. Source: HT