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Judi Lynn

(162,384 posts)
Fri Jun 30, 2023, 05:24 AM Jun 2023

There's a Giant Gravity Hole In The Indian Ocean, And We May Finally Know Why

30 June 2023
By CLARE WATSON



Geoid undulation in false color. (International Centre for Global Earth Models/Wikimedia, CC BY 4.0)

Gravity's pull is a constant on Earth, but our planet is no uniform sphere. It's covered in lumps and bumps, with geology of varying density yanking on nearby masses with subtly differing degrees of force in an undulating map known as a geoid.

Deep beneath the Indian Ocean, that pull weakens to an extreme low, leaving what is considered a massive gravity 'hole' some three million square kilometers in size roughly where the seafloor sinks into a vast depression.

One of the most profound gravitational anomalies on Earth, its presence has been alluded to for a while. Ship-based surveys and satellite measurements revealed long ago that the sea level just off the tip of the Indian subcontinent dipped on account of the gravitational tug-of-war between the aptly named Indian Ocean geoid low and the surrounding gravitational 'highs'.

Just what caused this relative weakening has never been clear. Now two researchers from the Indian Institute of Science think they have a better idea of the kinds of planetary phenomena that could be involved.

"All these [past] studies looked at the present-day anomaly and were not concerned with how this geoid low came into existence," geoscientists Debanjan Pal and Attreyee Ghosh explain in their published paper, which describes their new working hypothesis.

More:
https://www.sciencealert.com/theres-a-giant-gravity-hole-in-the-indian-ocean-and-we-may-finally-know-why

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There's a Giant Gravity Hole In The Indian Ocean, And We May Finally Know Why (Original Post) Judi Lynn Jun 2023 OP
Cool! Thanks for something interesting this morning. erronis Jun 2023 #1
Why not include this bit in the post ? rickford66 Jun 2023 #2
Makes me wonder if it is also moving northward along with the Indian tectonic plate pecosbob Jun 2023 #3
so coool johndenny251 Jun 2023 #4

rickford66

(5,665 posts)
2. Why not include this bit in the post ?
Fri Jun 30, 2023, 07:11 AM
Jun 2023
"They think the answer lies more than 1,000 kilometers (621 miles) beneath Earth's crust, where the cold, dense remnants of an ancient ocean plunged into a 'slab graveyard' beneath Africa some 30 million years ago, stirring up hot molten rock."
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