Khaberni - Researchers have uncovered a huge and mysterious rock formation underwater near Bermuda Island, they described it as "unparalleled on the face of the earth."
Recent study results, published in the journal Geophysical Research Letters, suggest that this structure might be the reason Bermuda has remained above sea level despite the cessation of volcanic activity over 30 million years ago, according to the "New York Post".
Normally, when volcanoes stop, the tectonic plate moves away from the deep mantle hotspot, and the volcanic crust gradually cools, leading to the slow sinking of the volcanoes. However, scientists have discovered an unusual rock layer beneath the ocean crust below Bermuda, which helps support the island and elevate it above the ocean floor.
This layer is about 12.4 miles thick, a level of thickness not seen in any comparable layer worldwide, according to the research team led by earthquake scientist William Fraser from the Carnegie Institution for Science and Jeffrey Park from Yale University.
The researchers used seismic waves generated by 396 distant earthquakes, all strong enough to transmit fine vibrations across the earth, to create a vertical image of the rock layers under Bermuda to a depth of about 31 miles. The analyses revealed a rock layer less dense than the surrounding rocks, explaining the continuation of the island's elevation above the ocean by about 500 meters (1640 feet) above the sea floor.
Fraser explained that "the unusual layer is positioned beneath the crust within the tectonic plate that Bermuda rests on, distinguishing it from the normal structure of the Earth's mantle."
He mentioned that the last volcanic eruption might have propelled earth mantle rocks to the crust where they froze, forming a raft-like structure above the ocean floor.
Meanwhile, Park stated that some magmatic materials may have stopped under the Moho layer instead of erupting on the surface, leading over time to the formation of what is known as "mafic rock pluton."
He added that "sub-crustal processing" might also have contributed, where the rise of hot materials allows the crust to crack and sea water to enter, thus modifying the upper earth mantle and forming lighter debris.
Geological scientist Sarah Maza from Smith College in Massachusetts explained that these remaining materials from the days of volcanic activity help support the island as a high site in the Atlantic Ocean, despite the cessation of volcanoes 31 million years ago.
The researchers indicate that the region was in the heart of the last great continents, adding a unique dimension to explaining this geological phenomenon, and the research team continues to study other islands around the world to determine whether this layer is unique or has counterparts elsewhere.
Fraser said: "Understanding a location like Bermuda, which represents an extreme case, helps us understand natural processes in less extreme places, and distinguish between ordinary and exceptional processes that occur on Earth."
