Subduction zones, the massive faults found where plates of dense ocean crust dive beneath continents, are the source of the world's largest earthquakes and tsunamis. Although GPS stations on land have revolutionized studies of the faults' movement, GPS radio signals cannot penetrate through the ocean to the sea floor, leaving large gaps in the study and hazard assessment of subduction zones. Techniques to track this movement, using GPS on ships tied to acoustic beacons on the sea floor, remain prohibitively expensive, though they have been embraced, with great success, in recent years by Japan. Now, U.S. scientists have developed a way to use ocean-going drones to replace ships, a move that many hope will greatly expand study of these faults. |
