The variety of recognized mountains in Earth’s oceans has roughly doubled. World satellite tv for pc observations have revealed practically 20,000 beforehand unknown seamounts, researchers report within the April Earth and House Science.
Simply as mountains tower over Earth’s floor, seamounts additionally rise above the ocean flooring. The tallest mountain on Earth, as measured from base to peak, is Mauna Kea, which is a part of the Hawaiian-Emperor Seamount Chain.
These underwater edifices are sometimes sizzling spots of marine biodiversity (SN: 10/7/16). That’s partly as a result of their craggy partitions — fashioned from volcanic exercise — present a plethora of habitats. Seamounts additionally promote upwelling of nutrient-rich water, which distributes helpful compounds like nitrates and phosphates all through the water column. They’re like “stirring rods within the ocean,” says David Sandwell, a geophysicist on the Scripps Establishment of Oceanography on the College of California, San Diego.
Greater than 24,600 seamounts have been beforehand mapped. One widespread means of discovering these hidden mountains is to ping the seafloor with sonar (SN: 4/16/21). However that’s an costly, time-intensive course of that requires a ship. Solely about 20 % of the ocean has been mapped that means, says Scripps earth scientist Julie Gevorgian. “There are quite a lot of gaps.”
So Gevorgian, Sandwell and their colleagues turned to satellite tv for pc observations, which offer world protection of the world’s oceans, to take a census of seamounts.
The crew pored over satellite tv for pc measurements of the peak of the ocean floor. The researchers regarded for centimeter-scale bumps brought on by the gravitational affect of a seamount. As a result of rock is denser than water, the presence of a seamount barely modifications the Earth’s gravitational subject at that spot. “There’s an additional gravitational attraction,” Sandwell says, that causes water to pile up above the seamount.
Utilizing that approach, the crew noticed 19,325 beforehand unknown seamounts. The researchers in contrast a few of their observations with sonar maps of the seafloor to substantiate that the newly found seamounts had been doubtless actual. A lot of the newly found underwater mountains are on the small facet — between roughly 700 and a couple of,500 meters tall, the researchers estimate.
Nonetheless, it’s doable that some might pose a danger to mariners. “There’s a degree after they’re shallow sufficient that they’re throughout the depth vary of submarines,” says David Clague, a marine geologist on the Monterey Bay Aquarium Analysis Institute in Moss Touchdown, Calif., who was not concerned within the analysis. In 2021, the USS Connecticut, a nuclear submarine, bumped into an uncharted seamount within the South China Sea. The vessel continues to be present process repairs at a shipyard in Washington state.
