A comparison between GEBCO Sheet 5.17 and the International Bathymetric Chart of the Arctic Ocean (IBCAO) version 1.0

In 1979, the General Bathymetric Chart of the Oceans (GEBCO) published Sheet 5.17 in the Fifth Edition of its series of global
bathymetric maps. Sheet 5.17 covered the northern polar region above 64 N, and was for long the authoritative portrayal of Arctic
bathymetry. The GEBCO compilation team had access to an extremely sparse sounding database from the central Arctic Ocean, due to
the difficulty of mapping in this permanently ice covered region. In the past decade, there has been a substantial increase in the
database of central Arctic Ocean bathymetry, due to the declassification of sounding data collected by US and British Royal Navy
nuclear submarines, and to the capability of modern icebreakers to measure ocean depths in heavy ice conditions. From these data sets,
evidence has mounted to indicate that many of the smaller (and some larger) bathymetric features of Sheet 5.17 were poorly or wrongly
defined. Within the framework of the project to construct the International Bathymetric Chart of the Arctic Ocean (IBCAO), all
available historic and modern data sets were compiled to create a digital bathymetric model. In this paper, we compare both generally
and in detail the contents of GEBCO Sheet 5.17 and version 1.0 of IBCAO, two bathymetric portrayals that were created more than
20 years apart. The results should be helpful in the analysis and assessment of previously published studies that were based on GEBCO
Sheet 5.17.