Authors: Jones, M., Sandwell, D., Beaman, R.
Publication: Fifth Annual GEBCO Bathymetric Science Day. IHO/IOC Committee for the General Bathymetric Charts of the Oceans (GEBCO), Callao, Peru.
SRTM30_Plus is a global 30 arc second topography/bathymetry grid based on the SRTM mapping of the land topography of the Earth (Farr et al., 2007) and the best available, mostly public domain, global bathymetric information. Predicted depths at 1 minute resolution (Smith and Sandwell, 1997) are refined using edited soundings (Becker et al., 2009). This grid forms the basis for the bathymetry in Google Earth (SRTM30_PLUS V4.0) and GEBCO08 (SRTM30_PLUS V5.0).
Over the past four years we have developed tools and methods for editing raw soundings at 500 m resolution. To date we have assembled 7295 files of soundings from a wide variety of sources such as the NGDC GEODAS data base (4636 files) (Figure 1 is a global map of soundings; the new soundings are in red and bold).
Over the past year we have added 2039 files of data that were not available from NGDC or any other archive. Most of these data were contributed by the National Geospatial Agency (1376 files) and they randomly fill gaps in coverage in all the oceans. In addition we assembled regional surveys from the Great Barrier Reef (Figure 2, Great Barrier Reef SRTM30_PLUS V5.0 and V7.0), Mediterranean Sea, Black Sea, Caspian Sea, and Gulf of California. In addition we added gridded data from major inland Lakes.
Approximately 3000 person-hours have been spent editing these mostly single-beam echo sounder data. For the past 4 years funding was provided by the National Science Foundation (OCE0326707).