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Screenshot of NGDC Trackline Geophysical Data Viewer
ESRI logo Trackline Geophysical Data Viewer

Data Types:
  • Bathymetry (Single Beam)
  • Gravity
  • Magnetics (including Airborne)
  • Seismic Reflection
    (Multi- & Single Channel)
  • Seismic Refraction
  • Shot-Point Navigation
  • Side Scan Sonar
  • Subbottom Profile

Also see:








World Data Service for Geophysics

Marine Trackline Geophysical Data

ESRI logoTrackline Geophysical Data Viewer

COMING SOON: A redesigned Marine Trackline Geophysical Data Request Page is in the works. Users will be able to request MGD77T data, digital and analog seismic data, legacy marine geophysical data sets, and more - all from one page. Stay tuned for the official release!
Preview the new (beta) data access system
Please send any comments to

NGDC's Marine Trackline Geophysical database provides access to bathymetry (single-beam), magnetics, gravity and seismic reflection data collected during marine cruises from 1939 to the present. Data sources include US and non-US oceanographic institutions, universities, and government agencies with worldwide data coverage.

Locating and Downloading Data

Data are distributed online via the Trackline Geophysical Data Viewer (an ArcGIS interactive map). Searches by geographic area, year of survey, institution, platform, survey name, date added to the database, and data type are available. Downloads can be customized to area, data type, and format.

Digital data can be exported in a variety of formats, including the MGD77T Exchange Format, and contain a documentation header record and a series of data records. Header records provide metadata for each survey. Data records contain geophysical data (bathymetry, magnetics, gravity, and seismic shot-point ids) with time and position.

Ancillary, analog and high-volume digital underway geophysical data, including seismic reflection and refraction, side-scan sonar, and other data types are also searchable and downloadable. Analog data are downloadable as scanned image files.

Contributing Data

NGDC is pleased to accept contributions of underway geophysical data on almost any media, preferably in the MGD77T Format. Any data received are in the international public domain, readily available globally to any interested individual or group. If you are interested in contributing data, please contact