Consolidation and Pore Fluid Pressure of Ursa Sediments, Deepwater Gulf

15 We conducted uniaxial compression tests on whole core samples from the Ursa 16 Basin, deepwater Gulf of Mexico, to obtain the consolidation properties of mudstones. 17 We showed that specific volume (v = 1+e) (where e is void ratio) declines as an 18 exponential function of effective stress and we used this relationship to successfully 19 predict in-situ pressure from void ratio at IODP Sites U1322 and U1324. This confirmed 20 high overpressures near the seafloor at Ursa. Rapid sediment compression near the 21 seafloor drives fluid flow, impacts overpressure, and ultimately controls land subsidence. 22 A better understanding of this behavior will allow us to better image the subsurface 23 acoustically, better predict subsurface pressure, and more completely understand the 24 global water cycle.