Sea Floor Mapping Group

Graphic showing geophysical and sampling systems used to define the seafloor topography, surface sediments, and underlying geology.  Sidescan-sonar systems acquire information about the surface of the seafloor, swath bathymetric systems measure the depth, or seafloor topography, seismic sources map the underlying geologic structure, single-beam echosounders map the depth at a point beneath the vessel, and sampling systems collect samples of the seafloor and can be equipped with digital camers and video systems to collect optical images of the seafloor.

Wayne Baldwin, USGS, deploys a sound velocity profiler off the stern of the R/V Stephens in Lake Powell, UT-AZ as part of a collaborative program with the Utah Water Science Center to map the depth and sediments within Lake Powell, UT-AZ.

Science Applications

SFMG uses acoustic and optical techniques to acquire detailed geologic information about the sea floor, such as seabed topography, sediment composition and distribution, and underlying geologic structure.  This information defines the geologic framework and provides a base for a wide-range of USGS research.

Each year the SFMG supports dozens of research efforts, most recently including:  gas hydrate and methane/carbon dioxide flux along the Atlantic margin; landslide and tsunami hazards along the mid-Atlantic and New England passive margin and the southeast Alaska active margin; characterization of mudflow hazards along the Mississippi River Delta Front; dive support for biological invasive species studies and benthic habitat studies; sediment characterization within the Stellwagen Bank National Marine Sanctuary; field observations in support of sea-level rise storm response studies along the east coast; and mapping lake floor topography and underlying stratigraphy in support of natural resource management within western reservoirs and Great Lakes. 

Sea Floor Mapping Capabilities

SFMG maintains a suite of instruments used to map the seafloor surface and underlying structure in shallow to deep-water environments.  These instruments include: multibeam, single-beam, and split beam echo sounders, sidescan-sonar, phase differencing bathymetric sonar, single- and multichannel seismic-reflection systems, and sample equipment designed to collect sediment samples, still photographs, and/or video images of the sea floor. 

SFMG is a diverse team of marine electronics technicians, engineers, geologists, physical scientists, geographers, and visual and imaging specialists.  This group has expertise in collecting, processing and interpreting geophysical and sample data in lacustrine, coastal and marine environments.  

USGS staff are preparing to deploy the Edgetech 512i sub-bottom profiling system from the stern of a research vessel.  The sub-bottom profiling system was used to map the geologic structure and sediments beneath the seafloor.

SFMG staff regularly collaborates with scientists at Universities, federal and state agencies, and the private sector to support collaborative research, and to help develop new software and hardware remote sensing techniques.