A new study has found that Earth’s subduction zones drag down roughly three times more water than previously estimated. The phenomenon has important implications for the global water cycle.
To conduct this study, researchers of Washington University in St. Louis listened to over a year’s worth of Earth’s rumblings – right from ambient noise to actual earthquakes. For this, they used a network of 19 ocean-bottom seismographs deployed across the Mariana Trench, which is the deepest ocean trench in the world, along with seven island-based seismographs.
Scientists believe that most of the water that goes down at the trench comes back from the Earth into the atmosphere as water vapor when volcanoes erupt hundreds of miles away. But with the revised estimates of water from the new study, the amount of water going into the earth seems to greatly exceed the amount of water coming out. The fact that the amount of water dragged down into the crust isn’t equal to the amount spouted back suggests that there’s something about how water moves through the interior of Earth that scientists don’t yet understand and any more studies need to be focused on this aspect.