The National Archive of Marine Seismic Surveys (NAMSS) is a marine seismic reflection data archive consisting of data acquired by or contributed to U.S. Department of the Interior agencies. The USGS is committed to preserving these data on behalf of the academic community and the nation. Data are provided with free and open access. For more information regarding NAMSS, see the about page.
The recent issues with downloading large files have been resolved. However, if you attempt to download a data zip file and that fails or the download speed drops to zero and does not resume, please send an email to firstname.lastname@example.org and include which file you were downloading and what city you are located, thank you.
Data Visualization Video
This video highlights the publicly available seismic data on NAMSS from the Gulf of Mexico. It was was created by Alexey Portnov (email@example.com) of Ohio State University. Thanks Alexey!
Most data are provided in SEG-Y format, (Barry, K. M., Cavers, D. A. and Kneale, C. W., 1975, Report on recommended standards for digital tape formats: GEOPHYSICS, 40, no. 02, 344-352, a copy of which can be found at: http://seg.org/News-Resources/Research-and-Data/Technical-Standards.) Specialized software is required to view SEG-Y data. A list of free software that can be used to visualize, analyze, and interpret 2D and 3D SEG-Y data can be found here. Data in the archive have associated metadata: at a minimum shotpoint location information in flat text files. Most surveys also have more complete metadata in the form of text reports and digital images (TIFF) of analog side-labels showing acquisition and in some cases processing parameters. Some profiles are represented by TIFF images of the reflection profile (not digital SEG-Y data). The site attempts to incorporate all metadata that were provided by the contributor. The metadata can be generated in an ISO-compatible XML template consistent with the metadata standard described at: https://www.ngdc.noaa.gov/mgg/ecs/metadata/seismic/.
While shotpoint location information is largely complete for all surveys, there may be gaps or erroneous locations and mismatches with the seismic traces. Not all datasets have been quality-controlled to ensure complete correlation between shotpoint locations and seismic profiles.
Triezenberg, P. J., Hart, P. E., and Childs, J. R., 2016, National Archive of Marine Seismic Surveys (NAMSS): A USGS data website of marine seismic reflection data within the U.S. Exclusive Economic Zone (EEZ): U.S. Geological Survey Data Release, doi: 10.5066/F7930R7P.
NAMSS currently holds:
241 3D seismic surveys covering 248,279 square kilometers.
568 2D seismic surveys with 33,402 tracklines covering 2,357,142 kilometers.
NAMSS is continuously updated as new surveys become available.