Downloaded September 2012 from
http://www.ngdc.noaa.gov/mgg/global/global.html
http://www.ngdc.noaa.gov/mgg/global/relief/ETOPO1/data/ice_surface/cell_registered/georeferenced_tiff/

Downloaded file:
ETOPO1_Ice_c_geotiff.zip
Original image file name:
ETOPO1_Ice_c.tif

For information on user restrictions, please visit
http://www.ngdc.noaa.gov/ngdcinfo/privacy.html

This page is also available offline in this folder, but note that terms might have changed since data download.