2015 AAAS Annual Meeting (12-16 February 2015)

February 12 - 16, 2015

Seeing Earth in the “Light” of Gravity: New Views Through Satellite Geodesy

Coupling advances in high-performance computing with space-based observation, satellite geodesy opens a new window on our dynamic planet: precise measurement and high-resolution modeling of Earth's gravitational field. This yields insights into processes ranging from plate tectonics to climate change and into hidden features that could guide resource exploration. Tiny variations in contours of the global gravity field, as captured by innovative satellite missions such as GOCE and GRACE, correspond to uneven distributions of mass. Thus, gravity offers a way to view the Earth that is complementary to approaches relying on light, magnetism, or seismic waves. But the picture can't be developed without high-performance computation: the GOCE mission alone gathered 800 million measurements and crunched the data into a 75,000 parameter model. One result is the most accurate representation yet of the (famously potato-shaped) geoid, a gravity-derived figure of Earth's surface that can serve as a global sea-level reference. Besides making it feasible to unify the different height systems in use around the world, the geoid gives scientists a reference for observing and imaging change. The picture that emerges shows ocean currents, as well as ice sheet melting, continental geology in otherwise inaccessible regions, and telltale signs of subduction and convection in the mantle. This session presents the current state-of-the-art and future directions in satellite geodesy and its applications.