Amante, C. and B. W. Eakins, ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis, National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce, Boulder, CO, August 2008. http://www.ngdc.noaa.gov/mgg/global/relief/ETOPO1/docs/ETOPO1.pdf
Imagery of ETOPO1 Ice Surface by J. Varner and E. Lim, Cooperative Institute for Research in Environmental Sciences, at University of Colorado at Boulder and NOAA National Geophysical Data Center.