Analog Data held by NGDC are inventoried in and searchable by GEODAS, but the data are not on CD/DVD. If you find surveys when searching for analog data, then you may contact NGDC for pricing information and arrange to receive copies of those data (e.g. reels of 35-mm microfilm; seismic reflection profiles on mylar, sepia, blackline; digital scans of 8.5 x 11 inch film negatives, etc.) Analog data found by a GEODAS SEARCH can be purchased from NGDC. If you find surveys when searching for Analog Data, then you may contact NGDC for pricing information and arrange to receive copies of those data (e.g. reels of 35-mm microfilm; seismic reflection profiles on mylar, sepia, blackline; digital scans of 8.5 x 11 inch film negatives, etc.) NOTE: Only the Marine Trackline Geophysics Database contains analog data at this time.
Digital Data identified by a GEODAS Search are available on CD/DVD, with the exceptions of digital seismic data and digital full resolution multibeam bathymetry (for these exceptions please contact NGDC for additional information)
Both Analog and Digital is a combination of both types of data. Surveys found by a Search for Both Analog & Digital may have analog and/or digital data available.
Include Data not at NGDC - Search results may include surveys that NGDC has inventoried but the data are not available from NGDC. Data not at NGDC may be available from the source organization (use Task -> Retrieve Headers to identify the source organization).
Only Data not at NGDC - Search results identify surveys for which data are inventoried and searchable by GEODAS but data are not available from NGDC. Data not at NGDC may be available from the source organization (use Task -> Retrieve Headers to identify the source organization). (NGDC holds a number of bathymetry data sets where the vertical beam of a multibeam bathymetry set has been extracted. NGDC may or may not hold the multibeam set itself.)