The proponents will mine 2-D seismic data collected in 2000 from Hydrate Ridge to better define the fracture networks and conduits beneath the summit region that are involved in transporting gas into and through the gas hydrate stability zone. Tasks to be undertaken to achieve this goal include 1) incorporation of a deterministic static correction to prestack seismic reflection data to correct for changes in water depth due to tides; 2) a different approach to binning and interpolating the prestack data to improve north-south continuity of slices through the seismic data; 3) construction of a 3D velocity model that integrates results from OBS travel-time tomography, VSPs, and sonic logging; 4) 3D pre-stack depth migration of the tide-corrected and interpolated reflection data; and 5) forward modeling of the wavefield using finite difference synthetic seismograms of individual shot and midpoint gathers to better understand amplitude affects due to seafloor scattering and separate them from those due to attenuation in the subsurface.
The potential broader impacts of this project include providing important background information needed for planning several large programs that are currently under development. It will also provide training for a promising young female post-doc. The 3D images of the subsurface plumbing of an active seafloor vent system will also be useful for transmitting the excitement of this research to the general public.
