The Indian Ocean Gravity Hole: A Dent in Earth’s Gravitational Field Explained
Summary:
The Indian Ocean gravity hole is a region of weak gravitational pull, discovered in 1948, where sea levels are significantly lower due to reduced mass. Recent research suggests it formed from the ancient Tethys Ocean’s crust fragments sinking into Earth’s mantle during Gondwana’s breakup. These fragments displaced dense magma, creating lighter plumes that weakened the gravity. Ongoing studies aim to confirm this with seismic data, revealing Earth’s interior complexities and similarities to planetary geology.
The “gravity hole” in the Indian Ocean is a region where Earth’s gravitational pull is unusually weak due to a reduction in mass. This phenomenon results in lower-than-average sea levels—about 348 feet (106 meters) lower than surrounding areas—making it the most significant dent in Earth’s gravitational field. Discovered in 1948, this “geoid low,” as scientists term it, puzzled researchers for decades until a breakthrough study in 2023 provided a plausible explanation.
Spanning 1.2 million square miles (3.1 million square kilometers), this anomaly is located 746 miles (1,200 km) southwest of India. The recent study, published in Geophysical Research Letters, utilized 19 computer models to simulate 140 million years of Earth’s mantle and tectonic plate movements. These models traced the gravity hole’s origins to the ancient ocean Tethys, which existed between the supercontinents Laurasia and Gondwana.
About 180 million years ago, the Tethys Ocean began to vanish as its crust slid beneath the Eurasian plate during Gondwana’s breakup. Fragmented pieces of this crust sank deep into Earth’s mantle. Roughly 20 million years ago, these fragments reached the mantle’s lowest layers, displacing dense material linked to the “African blob”—a massive crystallized magma structure beneath Africa. The displaced dense material was replaced by lighter magma plumes, reducing the region’s mass and gravitational strength.
While the models offer a strong hypothesis, scientists are working to confirm their findings through seismic data to identify these low-density magma plumes. This discovery highlights Earth’s complex interior, full of strange magma “blobs,” some of which have surprised researchers by appearing in unexpected locations.
Interestingly, similar underground anomalies are being discovered on other planets, including Mars, underscoring the universality of such geological phenomena.
Stay Updated!
Join our WhatsApp Channel for the latest updates, exclusive content, and more! Click the link below to join now:
👉 Join Our WhatsApp Channel