Global distribution of seamounts from machine learning

The ocean floor is littered with seamounts, most of which are volcanic in origin. Seamounts are important in the marine geosciences because they are oceanographic ‘dip-sticks’, biodiversity hotspots, scatterers of tsunami waves, and hazards for navigation. Research ships with single beam echo-sounders have discovered many small seamounts and some large ones while satellite altimetry has led to discovery of many large seamounts and some small ones. The exact number of seamounts in the world’s ocean basins and their margins remains, however, unknown.  Here we use machine learning in an attempt to locate all seamounts, to estimate their height and volume and to speculate on their origin. We use the seamounts found by Hillier & Watts (2007) along ship track from single beam echo-sounder data acquired on 5585 individual research cruises during 1950 to 2002 as a ‘training’ data set and the SRTM15+V2.7 (GEBCO 2025) topographic grid that combines shipboard single beam and multibeam (swath) bathymetry data acquired on 2154 individual research cruises during 1980 to 2024 with predicted bathymetry from satellite altimeter data in regions of sparse ship tracks to determine the 6 main attributes (channels) of seamounts, 4 of which refer to their slopes. We then use the SRTM15+V2.7 (GEBCO 2025) topographic grid together with machine learning to update the global seamount census of Hillier & Watts (2007). Preliminary results in two pilot study areas on old and young oceanic crust in the Pacific Ocean indicate that machine learning yields up to a factor of 2 more seamounts than were identified in the training data set. The implications of these results are examined for volcanism on Earth and on other terrestrial planets.

References:

Hillier, J.K., Watts, A.B., 2007. Global distribution of seamounts from ship-track bathymetry data. Geophys. Res. Letts. 34, 1-5, doi:10.1029/2007GL029874.

Tozer, B., Sandwell, D.T., Smith, W.H.F., Olson, C., Beale, J.R., and Wessel, P., 2019 Global Bathymetry and Topography at 15 Arc Sec: SRTM15+. Earth and Space Science 6, doi:10.1029/2019EA000658