A team of scientists aboard a drilling vessel off the coast of the Azores (Portugal) has collected the first samples taken from the mantle surrounding the Earth’s core.
They hope these samples will shed light on the chemical reactions that gave rise to life on our blue planet.
The Earth is primarily composed of three layers: the crust, the mantle, and the core. (Illustrative image).
According to Sputnik, the scientists achieved this milestone thanks to a rare location on the seabed of the Atlantic Ocean. Typically, the mantle lies kilometers deep beneath the Earth’s crust. However, at this special site beneath the Atlantic Ocean – the Massif underwater mountain, researchers were able to penetrate the crust at a depth of only 1.2 kilometers and sample the mantle. In previous sampling efforts, scientists had to drill through the 32-kilometer thick crust to reach the mantle.
Scientists report that the success of the JOIDES drilling ship far exceeded expectations, and instead of a small sample, they obtained a large volume of mantle soil samples.
“We have never drilled this deep into the Earth’s crust since the 1960s. We have achieved a milestone that can answer questions posed by the scientific community for decades,” said Andrew McCaig, the lead scientist of the expedition, to American media outlets.
Although the JOIDES drilling vessel has only reached the boundary between the Earth’s crust and mantle, known as the Moho, named after Croatian seismologist Andrija Mohorovičić who proposed it in 1909, the collected rock samples are mantle rocks, specifically peridotite in a relatively unweathered form. Typically, mantle rocks can be found on the surface after a volcanic eruption, but they are often damaged due to the molten lava process.
Previously, scientists had attempted projects to access the Earth’s mantle but failed. The first was a U.S. project in the early 1960s off the coast of Mexico called the Mohole Project, which only managed to drill to a depth of 108 meters beneath the seabed. The second was a German project in Bavaria from 1987 to 1995, with the KTB super-deep borehole reaching a depth of 9.1 kilometers but had to stop upon encountering rock at a temperature of 260 degrees Celsius.
However, the deepest point ever reached by humans is the Kola super-deep borehole in the Soviet Union, drilled in the northwestern region of the country from 1970 to 1995, reaching an astonishing depth of 12.2 kilometers. Unfortunately, the workers on this project could not drill deeper as the continuously molten rock melted the drill bits.
