New drone technology is set to replace expensive ships used for reading potential earthquakes in subduction zones, the region of the Earth's crust where tectonic plates meet. The National Science Foundation (NSF) recently announced a $5.5 million grant to purchase three ocean-going drones and beacons for 16 seafloor sites from a team of Geophysicists, led by David Chadwell.
GPS is used by Earth scientists to measure the strain in subduction zones and GPS stations signal when enough strain gets accumulated to drive a possible high magnitude earthquake. But the threat can also subside if land-based measurements hint a relief in the strain by a type of harmless slip called creep. Such an event indicates that the fault could rupture into pieces, leading to smaller quakes.
In the case of offshore measurements, scientists fail to see the full picture and acoustic GPS are used to get more reliable data. Since radio signals of Global Positioning System (GPS) can not penetrate deep ocean, scientists earlier relied on a chain of events to determine the threat where a ship was used to track acoustic beacons on the seafloor and fixed its position with GPS. NSF has been using ships to get the readings in the subduction zones which can cost up to $50,000 per day.
Japan, vulnerable to high-intensity earthquake and Tsunami, has already spent more than $3 billion on acoustic GPS over the past 10 years. It has planned to include 27 stations in its acoustic GPS network by the end of 2020 with multiple beacons for every station.
Talking to Science Magazine, Laura Wallace, a geodetic scientist at GNS Science in New Zealand, said that the drones are going to make a huge difference. NSF’s new approach will improve the ability of scientists, by more than double, to track movements of the ocean floor. The decision regarding the deployment of the new instruments has not yet been made by the NSF but it is enough to cover at least one subduction zone in detail.