New Delhi: The mysterious Bermuda Triangle is of interest to conspiracy theories because of the large number of ships and aircraft that have disappeared
in the region, but scientists have long been baffled by a mysterious rise in the ocean, or a swell. Most underwater mountains and swells form from molten rock rising up from deep within the interior of Earth, creating chains of volcanoes that move over the rising mantle. Bermuda does not have a young volcano chain, no recent lava flows, and no sign of hot spots, but the area around the island is elevated by about 500 metres above the surrounding seafloor, defying conventional explanations.
A new study sheds light on the puzzle. Seismometers provide scientists with a valuable insight into the remote interior of the Earth, revealing subsurface structures. Examining the data captured by a seismic station at Bermuda revealed that beneath the 7km thick ocean crust, there was an extra layer of rock about 20km thick, roughly twice the thickness of similar features on other ocean islands. This extra layer of rock is believed to have formed between 30 and 35 million years ago when the region was volcanically active. The layer itself provides the lift as it is made up of low density material, acting as a buoy floating in matter.
A new understanding of isolated ocean swells
The discovery challenges the conventional understanding of ocean swells, and demonstrates that not all ocean swells need constant deep heat, with some being caused by permanent underground changes. The layer of rock also explains why the swell has not sunk over millions of years. There are similar thick layers of rock at a few other sites, indicating that the mechanism may be able to explain more ocean mysteries worldwide. A paper describing the research has been published in Geophysical Research Letters.
