Water below the earth's surface can stimulate earthquakes.
Over the past million years, more than 79 million tons of water have been sucked into the deep layers of the earth's mantle through a tectonic fault in the Mariana Trench, writes Live Science.
Scientists have known for a long time that during the movement of tectonic plates in subduction zones (where one layer of the lithosphere is superimposed on another), part of the world's ocean water inevitably seeps inward. However, the volume of absorbed water was three times higher than the expected figure.
This discovery is important for understanding not only the deep-sea cycle of the Earth, but also the nature of earthquakes, as water below the surface can stimulate magma formation and erode faults.
Researchers at the University of Washington used data collected by a network of seismic sensors located around the Mariana Trench, where the Pacific plate meets the Philippine plate. The maximum depth of the depression is 11 kilometers below sea level.
These sensors are designed to detect earthquakes and their echoes. However, scientists from Columbia University have figured out how to use them to measure the amount of water that gets inside the fault: when it gets into the bowels of the Earth, water is conserved in the crystal structure of minerals, and by the nature of the echo from earthquakes, which the sensors record, you can calculate their content in the plates.
