Marine seafloor sediment profiling and classification in the Arctic Ocean

Abstract

Ocean Data Equipment Corporation redesigned their FM Chirp sub-bottom profiler, the Bathy 2000P, for operation aboard a US Navy Sturgeon-class nuclear powered submarine. Normally operated from a surface vessel, the Bathy 2000P was customized to meet specifications provided by scientists from Lamont-Doherty Earth Observatory of Columbia University for use as an Arctic research tool. An overview of the system design criteria is given that details the difficulties posed by operation aboard a submarine surveying in the Arctic and how the system was tailored to meet the scientific objectives for operation in a complex environment. Successful operation of the Bathy 2000P during two annual Submarine Science Ice Expeditions (SCICEX) has provided seafloor and sediment sonar data previously unavailable to the scientific community. High-resolution acoustic images of the Arctic marine sub-bottom and topographic contours are presented and corroborate the use of a submarine as a platform for acoustic acquisition of geophysical data. Additional processed data, generated using a unique suite of algorithms to derive spectral and absorption loss characteristics are presented. These techniques illustrate the possibility of extending our geophysical knowledge through sediment characterization of the Arctic basin without the need for extended physical sampling.