For decades, the existence of a massive “gravity hole” in the Indian Ocean has been one of the greatest natural mysteries of our planet — until now.
What a “gravity hole” is: In simple terms, a “gravity hole” is an area where gravity is so low that it causes sea levels to sink. On Earth, there are many gravity holes. They exist because the planet is not a perfect sphere and because materials underneath its surface have varying densities. Where there is less mass, there is less gravity.
The Indian Ocean’s hole: The gravity hole in the Indian Ocean was first discovered by Dutch geophysicist Felix Andries Vening Meinesz in 1948. Scientifically called the Indian Ocean Geoid Low (IOGL), it is a circular depression where the sea level plunges by over 328 feet.
How it was formed: How the IOGL came to be has perplexed geologists since its discovery. But scientists from the Indian Institute of Science and GFZ German Research Centre for Geosciences now suggest in a study published in journal Geophysical Research Letters that magma plumes coming from deep inside the Earth could be behind it.
Six of 19 simulations that recreated tectonic shifts and magma movements in the Earth’s mantle from 140 million years ago to the present revealed the existence of such plumes. The scientists said they originated from the disappearance of an ancient ocean as India collided with Asia 40 million years ago.
What’s next: The future of the Indian Ocean gravity hole is yet to be seen, study coauthor Attreyee Ghosh, a geophysicist and associate professor at the Indian Institute of Science, told CNN.
That all depends on how these mass anomalies in the Earth move around. It could be that it persists for a very long time. But it could also be that the plate movements will act in such a way to make it disappear — a few hundreds of millions of years in the future.