The 2005 HOTRAX Expedition to the Arctic Ocean

The Healy–Oden Trans-Arctic Expedition (HOTRAXʹ05) recovered 29 long piston cores and associated multicores along a transect from the Alaskan margin across the central Arctic Ocean to the northern Svalbard margin. The initial results focus on the age and stratigraphy of these cores using a variety of approaches including radiocarbon, paleomagnetic and other chronostratigraphic methods as well as detailed correlations of proxy records. High sedimentation cores from probable drift deposits are described from the shelf and continental slope north of Alaska. Provenance and sedimentary processes in these deposits include both currents and sea-ice rafting. Much lower sedimentation rates in the central Arctic Ocean show geographic variability consistent with the patterns of expected sediment distribution by ice and, to a smaller extent, subsurface currents. Insights into the Upper Quaternary stratigraphy and depositional history are provided in two papers on a core from the Mendeleev Ridge with sedimentation rates relatively elevated for this region. To compliment the results from the HOTRAX cores, two papers are included dealing with the stratigraphy and sedimentary processes on the Chukchi shelf and a modeling study addressing why the Marine Isotopic Stage 6 (ca. 140 ka) glaciation was substantially more extensive in the Arctic than the Last Glacial Maximum.