Navy-Funded Scientist Wins Award for Groundbreaking Seafloor Map
Dr. David Sandwell, a geophysicist at Scripps, has been awarded American Geophysical Union's Charles A. Whitten Medal for creating the world's first comprehensive, high-resolution map of the ocean floor.
In a long-running project sponsored by the U.S. Navy's Office of Naval Research, Sandwell combined satellite data with sonar measurements to develop a global depth chart of unprecedented detail. His work has charted thousands of previously unidentified mountains, trenches, and other features in the deepest and least explored parts of the ocean. The work is not only of academic interest: it provides crucial intelligence and scientific information for the Navy.
"Dr. Sandwell’s groundbreaking work provides the first high-resolution map of the ocean floor,” said Dr. Tom Drake, head of ONR’s Ocean Battlespace and Expeditionary Access Department. “This has opened new research areas for oceanography, marine geology and geophysics - critical topics for the U.S. Navy.”
Sandwell’s work relied on sensitive satellite radar altimetry to measure small bumps and dips on the ocean surface, which reflect the gravitational pull of large-scale features on the ocean floor. For example, undersea mountains are large enough to exert gravitational effects that gather water in a bump on the sea surface. In contrast, massive cracks and rifts on the ocean floor have less gravitational attraction, resulting in a dip on the surface. Sandwell also incorporated sonar soundings - which are highly detailed, but cover a much smaller area of the world's oceans - to improve chart accuracy.
The first edition of Sandwell's chart came out in 1997. He updated the original in 2014 with more data from NASA and the European Space Agency, and he is now creating a third edition with more new information. In particular, the new work will incorporate the sonar soundings obtained during the search for Malaysian Airways Flight 370.
“Thanks to this new data, our map can provide greater information about the world’s oceans,” said Sandwell, “particularly the Southern Hemisphere, [including] the Indian Ocean and south Atlantic Ocean."