Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Red–locations sampled in 1973 and 2018; green– 2018 sampling only. Circles represent exposed locations; triangles represent sheltered locations. Data from GEBCO Compilation Group (2019) GEBCO 2019 Grid (doi:10.5285/836f016a-33be-6ddc-e053-6c86abc0788e) and Natural Earth, free vector and raster map data @ naturalearthdata.com.
