By the way, I know the very term sounds quite intriguing – so where exactly is this giant gravity hole? It is located in the Indian Ocean. I know what you’re thinking: an ocean housing a gravity hole sounds bizarre, but it’s not a typical hole from where water is seeping. You see, our planet does not have uniform gravity in all parts. The strength of the gravitational pull in any region of the world depends on the mass of the Earth’s crust, the mantle, and the core beneath that part. And this massive region in the Indian Ocean has an extremely low pull of gravity.
Where exactly in the Indian Ocean?
About 1,200 kilometers southwest of the southernmost tip of India.
How massive is this region?
Over 3 million square kilometers wide. And just how low is the gravitational pull? It is so low that the sea level of the Indian Ocean over this so-called hole is around 106 meters lower than the global average.
This gravity hole is called Indian Ocean Geoid Low, or IOGL. It was discovered in 1948 during a survey by a Dutch geophysicist, but till now scientists were not really able to figure out the reason for this.
What really caused this depression?
Here’s what’s been found: A research article published in the journal Geophysical Research Letters has the answer to this big question. Researchers from the Indian Institute of Science in Bengaluru, India, document what they believe caused the gravitational anomaly. More than a dozen computer models were studied. The models looked at how the region formed over the past 140 million years as the Earth’s tectonic plates shifted.
So what’s the conclusion?
Scientists say this gravity hole may be due to low-density plumes of magma disturbed by the sinking slabs of a former tectonic plate. Basically, molten rock plumes were found below Africa in all the simulations, which could potentially have been caused by tectonic plates plunging into the mantle. And they believed that this could be the reason behind the so-called gravity hole. But they also believe that there are still other factors that need to be unearthed before arriving at a conclusion.
Life in the Gravity Anomaly Region
What’s life like in this region with unusually low gravitational pull? Interestingly, there’s this little blip in gravity that really doesn’t do much to affect people very much who live close to it. The gravity difference is so subtle that humans cannot perceive it without sensitive instruments. Near this place out on the sea, shipping nays guys and island communities alike go about their business without any remarkable effects at all. Marine ecosystems thrive throughout this area, with the gravity anomaly having no known impact on ocean currents, fish migration patterns, or coral reef development. The fishing communities and shipping lanes that traverse this region operate just as they would elsewhere in the Indian Ocean.
For researchers and scientists this is a really exciting opportunity to study the natural world in a fabulous way. Oceangoing research ships take repeated trips to this special place to measure stuff like gravity and take detailed maps of the bottom of the seabed. They collect data that points to the uniqueness of the phenomenon they’re tracking. The place is really starting to feel like a magnet for scientists, and teams from around the world come back often to check on things like changes in the earth’s gravitational field and try to connect those fluctuations with other natural things like ocean currents or climate patterns. While visitors to this part of the world won’t experience anything out of the ordinary, it’s actually passing right through some of Earth’s grandest gravitational landscapesโthis is a deeply significant reminder of just how dynamic and varied our planet’s physical characteristics truly are.
