Hypsometry and volume of the Arctic Ocean and its constituent seas

Abstract

[1] This paper presents an analysis of the Arctic Ocean and its constituent seas for seafloor area distribution versus depth and ocean volume. The bathymetry from the International Bathymetric Chart of the Arctic Ocean (IBCAO) is used together with limits defining this ocean and its constituent seas from the International Hydrographic Organization (IHO) as well as redefined limits constructed to confine the seas to the shallow shelves. IBCAO is a bathymetric grid model with a resolution of 2.5 Â 2.5 km, which significantly improved the portrayal of the Arctic Ocean seafloor through incorporation of newly released bathymetric data including echo soundings from U.S. and British navies, scientific nuclear submarine cruises, and icebreaker cruises. This analysis of seafloor area and ocean volume is the first for the Arctic Ocean based on this new and improved portrayal of the seafloor as represented by IBCAO. The seafloor area and volume are calculated for different depths starting from the present sea level and progressing in increments of 10 m to a depth of 500 m and in increments of 50 m from 550 m down to the deepest depth within each of the analyzed seas. Hypsometric curves expressed as simple histograms of the frequencies in different depth bins and depth plotted against cumulative area for each of the analyzed seas are presented. The area and volume calculations show that the entire IHO-defined Arctic Ocean makes up $4.3% of the total ocean area but only $1.4% of the volume. Furthermore, the IHO Arctic Ocean is the shallowest (mean depth 1201 m) of all the major oceans and their adjacent seas. The continental shelf area, from the coasts out to the shelf break, make up as much as $52.9% of the total area in the Arctic Ocean, defined in this work as consisting of the oceanic deep Arctic Ocean Basin; the broad continental shelves of the Barents, Kara, Laptev, East Siberian, Chukchi, and Beaufort Seas; the White Sea; and the narrow continental shelf off both the Canadian Arctic Archipelago and northern Greenland. This result indicates that the Arctic Ocean has significantly larger continental shelves compared with all the other oceans, where previous studies show that the proportion of shelves, from the coasts out to the foot of the continental slopes, only ranges between about 9.1 and 17.7%. Furthermore, the derived hypsometric curves show that most of the Arctic Ocean shelf seas besides the Barents Sea, Beaufort Sea, and the shelf off northern Greenland have a similar shape, with the largest seafloor area between 0 and 50 m. The East Siberian and Laptev seas, in particular, show area distributions concentrated in this shallow depth range, and together with the Chukchi Sea they form a large flat shallow shelf province composing as much as 22% of the entire Arctic Ocean area but only 1% of the volume. This implies that the circulation in the Arctic Ocean might be very sensitive to eustatic sea level changes. One of the aims with this work is to make up-to-date high-resolution area and volume calculations for the ...

An Arctic Ocean ice shelf during MIS 6 constrained by new geophysical and geological data

“…The results are obtained using present-day conditions in the Arctic; i.e. A z 9 Â 10 12 m 2 , e z 10 À3 W m À2 , and Dr T z 0.2 kg m À3 (values are from (Jakobsson, 2002;Stigebrandt, 1981). The present-day freshwater input to the Arctic is about 0.28 Sv of which 0.09 exits through the Canadian Archipelago (Dickson et al, 2007).…”

Nordic seas transit time distributions and anthropogenic CO2

“…where Inv org and V org are the inventory and volume estimates determined through the mapping routine and V J is the volume estimates of Jakobsson [2002]. This scaling changed the Greenland Sea inventory estimate by 2%, the Norwegian Sea estimate by 0.8%, and the estimates for the Iceland Sea and Denmark Strait by 0.3% and 10%, respectively.…”

“…The limits between the subregions were set as by Jakobsson [2002] who follows International Hydrographic Organization [2001]. The ocean volumes estimated through our mapping routine (Table 1) do not match the volume estimates determined from the International Bathymetric Chart of the Arctic Ocean (IBCAO) exactly [Jakobsson, 2002].…”

“…This is caused by the lower resolution of the bathymetry (the 5 min TerrainBase of NOAA/National Geophysical Center) used for the mapping as well as the 50 m layer thickness. Therefore all inventories have been scaled to the ocean volumes published by Jakobsson [2002] using the simple normalization equation…”

Automatic processing of high‐rate, high‐density multibeam echosounder data

“…These data sets can provide data for constructing nautical charts and, in different depth ranges, provide insight into the processes that are forming and re-forming the earth. From the study of ocean ridge formation [Grevemeyer et al, 2002;Fox, 1996] to the formation of continental margins [Gardner et al, 2001a;Eichhubl et al, 2002;Lee et al, 2002] and mapping for ocean exploration [Dziak et al, 2001], baseline maps of the ocean floor provide the geospatial foundations for most ocean studies, and a source of innovation for new investigations [Jakobsson, 2002;Bacon et al, 2002].…”