An official website of the United States government
Here’s how you know
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.
American; ice-breaking ship dedicated to scientific research and operated by the National Science Foundation for Antarctic scientific missions since 1992.
Reference
[301] - Polar Icebreakers in a Changing World, by the National Research Council: National Academies Press, District of Columbia, 2007.
Updated
Oct 12, 2016 12:25 PM
The boundaries shown on the maps above are approximate and are intended
only to portray the locations of named features and their rough extents.
Changes in the control network drop down are not reflected automatically on the map.
You may wish to select a different layer on the map to match the control network
for the geometry you are viewing.