Trans-Arctic Coring Expedition Results

This summer one of the most ambitious coring expeditions to the central Arctic followed on the heals of the highly successful IODP drilling on the Lomonosov Ridge in 2004. The geological objectives of the Healy-Oden TransArctic Expedition (HOTRAX) were to (1) establish a rigorous, verifiable stratigraphic framework for Quaternary deposits, and (2) recover expanded stratigraphic sections of the Holocene and older strata back to the last major interglacial interval (O-18 stage 5e) from sites across the entire Arctic Ocean. These cores will then be used to construct a pan-Arctic stratigraphy and paleoclimate record at as high a resolution as possible. This paper reports on the initial stratigraphy developed by a team of international Arctic researchers immediately after the cruise. The records represent some of the best stratigraphic sections recovered thus far for the last few glacial stages and will provide paleoclimatologists excellent archives to work from in the next several years. Based on the preliminary stratigraphy and 3.5 KHz acoustical data used to site the cores, expanded records for the last glacial and Holocene were obtained from several locations, primarily from the continental slope north of Alaska. Other targeted sites investigated include the Northwind Ridge, Mendeleev and Alpha Ridge system, the Lomonosov Ridge gap, the Gakkel Ridge, and the Yermak Plateau. Future work will involve detailed stratigraphic work to construct age models for these cores and then an array of paleoceanographic and paleoclimate research to develop the best possible Arctic paleoclimate record.