High-Resolution Marine Gravity, Seafloor Topography, and Seafloor Roughness

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The PIs will improve the precision and resolution of marine gravity and topography by re-tracking the waveforms of the ERS-1 and Geosat altimeters to better image local gravity anomalies for: 1) resolving the fine-scale tectonic structure of the deep ocean floor (e.g., abyssal hills, microplates, propagating rifts, seamounts, meteorite impacts, . . .); 2) measuring the roughness spectra of the seafloor on a global basis to better constrain models of tidal dissipation, vertical mixing, and mesoscale circulation of the oceans; and 3) resolving the fine-scale gravity field of the continental margins for basic research and petroleum exploration. The work funded here will make a factor of 2 improvement in the global gravity models. The improvement will be more significant in near-shore areas where Geosat data are missing. Funded tasks include: a. re-track the waveforms of ERS-1 altimeter to reduce the noise by a factor of 2; b. re-track the waveforms of the Geosat altimeter to reduce the noise by 20%; c. combine altimeter data from Geosat, ERS, GFO, Topex, and Jason-I to develop new marine gravity models using long-wavelength fields (> ~400 km) from CHAMP and GRACE as constraints; d. construct a new global topography model based on the best available gravity and topography data; e. perform scientific investigations of small-scale tectonics, seafloor roughness, and isostasy.