Ten years of seismic oceanography: Accomplishments and challenges

Abstract

“Seismic oceanography” (SO)—the use of low-frequency marine seismic reflection data to image thermohaline fine-structure in the water column—began in 2003, with the publication of a paper in Science. Over the past ten years, the nascent SO community has demonstrated that reflection seismology can image thermohaline fine structure, over large areas, from temperature contrasts in the ocean of only a few hundredths of a ̊C. The resulting images illuminate many diverse oceanic phenomena, including fronts, water mass boundaries, internal wave displacements, internal tide beams, eddies, turbulence, and lee waves. Beyond merely producing spectacular images of ocean structure, low-frequency reflections can be processed to produce quantitative estimates of sound speed (and thus ocean temperature), turbulence dissipation, and vertical mode structure over full ocean depths, as long as fine-structure reflections are present. Yet SO has failed to become a standard tool for physical oceanographers, partly due to disciplinary boundaries, and partly due to the perceived high expense of seismic data acquisition. I will present examples of the successes of SO and discuss approaches to meet the challenges to the adoption of SO as a commonly used technique to study physical oceanographic processes.