For each tsunami earthquake region, ship-based bathymetric data have been collated from German (http://www.bsh.de), French (http://en.data.ifremer.fr), Japanese (http://www.godac.jamstec.go.jp/darwin/e) and US (http://www.rvdata.us) research cruises as well as the compilation of data provided by the Global Multi-Resolution Topography (GMRT) synthesis (https://www.gmrt.org). The ship-based bathymetric soundings were quality checked and manually edited if necessary. The collated data is displayed on top of the SRTM15+ grid (https://www2.jpl.nasa.gov/srtm). For the New Zealand margin the collated data is displayed on top of the nationwide bathymetric compilation provided by The National Institute of Water and Atmospheric Research (NIWA) (https://www.niwa.co.nz/our-science/oceans/bathymetry).

Supplement to: Geersen, Jacob (2019): Sediment-starved trenches and rough subducting plates are conducive to tsunami earthquakes. Tectonophysics, 762, 28-44