Figure S3. Sea-surface height in cm from Aviso (http://www.aviso.oceanobs.com) on the day of sampling for PS17-18 (black triangle), April 1, 2017. This position is coincident with the site of the former Deepwater Horizon oil rig. This image was produced by NOAA/AOML (https://www.aoml.noaa.gov/phod/dhos/altimetry.php).