The Global Multi-Resolution Topography (GMRT) synthesis is a free, global map of seafloor and land elevations. It combines high-resolution multibeam data from over a thousand ocean research expeditions with other publicly available elevation data. Created by scientists and data experts, GMRT is carefully checked for quality and includes detailed information about where the data came from and how it was processed.

GMRT helps researchers, educators, and planners by providing an easy-to-use, well-documented dataset that saves time and avoids duplication of effort. It’s updated regularly and includes both new and older (legacy) data. Users can access GMRT through online tools and services like GeoMapApp.

Because GMRT brings together so much detailed information in one place, it’s especially useful for modern science approaches like machine learning, modeling, and global comparisons. GMRT make it possible to keep learning from data we’ve already collected—helping scientists make new discoveries while using resources more efficiently.