Last deglaciation and last glacial climatic record from the new coastal TALDICE ice core (East Antarctica)

The TALDICE project retrieved a new ice core from a peripheral dome of East Antarctica. Talos Dome (72° 49’ S, 159° 11’ E; 2315 m; 80 kg m-2 yr-1; -41°C) is located in the Northern Victoria Land, close from the Ross Sea. Back-trajectory analyses suggest that the site is mostly fed by air masses arriving both from the Pacific (and Ross Sea) and Indian Ocean sectors. In December 2007 the drilling team reached the depth of 1619.2 m. A preliminary dating based on an ice flow model and an inverse method suggests an age of about 300,000 years BP at 1560 m of depth. We measured the methane (CH4) mixing ratio in the Talos Dome ice core at a depth resolution ranging from 0.5 to 4 m. Two laboratories (LGGE and Bern) were involved, using slightly different techniques. The CH4 mixing ratio measured in the TALDICE ice core allows us to define tie points with respect to other ice cores from Greenland and Antarctica, using in particular the rapid CH4 changes associated with the last termination and the D/O events. Additional chronological constraints are offered by the isotopic composition of molecular oxygen, the dust profile, and volcanic peaks. The comparison of water isotopic profiles from Talos Dome, EDC, EDML (Antarctica) and North-GRIP (Greenland) ice cores, once put on a common time scale, reveals that during the last deglaciation, climatic changes at Talos Dome were essentially in phase with the Antarctic plateau, and that the bipolar seesaw is also valid for this coastal site. A similar comparison extended to the last glacial period (work in progress) enables us to evaluate the timing, shape and duration of the Talos Dome warm events with respect to AIM events on the Antarctic plateau, and to the Dansgaard/Oeschger events in Greenland.