Seismic measurements have revealed a large amount of water east of New Zealand, under the Pacific Ocean. In terms of quantity, water at sea level lies three kilometers below the Earth’s crust and may play an important role in mitigating earthquakes in the region.
New Zealand lies on a fault line where the Pacific plate subducts beneath the Australian-Indian plate. The movement of the crust here is linked to what are called slow earthquakes, meaning they cause movements of the ground that continue for hours and days, which should not be confused with the fast and powerful earthquakes that cause tsunamis.
Science already knew that seawater flows beneath the crust, and it was hypothesized that slow earthquakes might be involved in this process. The water discovered using 3D seismic imaging is the first direct evidence of its existence.
We can’t see deep enough to see exactly what’s happening at the break, but we can see that the amount of water coming down is much higher than normal
– explained the research author Andrew Gas, a fellow at the Institute of Geophysics at the University of Texas UTIG. the Advancement of scienceThe researchers collected data for the study published in 2008 by sailing and conducting test drilling operations, and Gaz himself suggested conducting deeper drilling operations in order to better understand this phenomenon.
Photography by Andrew Gas
The deep waters were found beneath a massive volcanic zone created by a lava flow the size of the United States 125 million years ago. It was one of the most powerful volcanic eruptions ever known and lasted for millions of years. By examining volcanoes hidden beneath layers of sediment deep within the volcanic plateau, Gaz and his colleagues determined that half the volume of samples brought to the surface by drilling was filled with water.
Normal ocean crust should contain less water when it is 7 to 10 million years old
The specialist noted.
This discovery is important because, according to scientists, water pressure is an important factor that allows the pressure energy accumulated in tectonic plates to be released slowly and gradually. This can happen when water-rich sediments that lie beneath the fault become trapped beneath the crust. However, there are no such deposits in New Zealand, according to the researchers, here ancient volcanic and metamorphic rocks are now being absorbed through the fracture in the form of clay.
The most important thing, according to specialists, is that laboratory experiments and simulations have now been confirmed with real data, and they believe that this process is taking place in a similar way in several places along the fault lines.
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