An 83 000-year-old ice core from Roosevelt Island, Ross Sea, Antarctica

• Published in: Climate of the Past
• Main Authors: Lee, James E., Brook, Edward J., Bertler, Nancy A. N., Buizert, Christo, Baisden, Troy, Blunier, Thomas, Ciobanu, V. Gabriela, Conway, Howard, Dahl-Jensen, Dorthe, Fudge, Tyler J., Hindmarsh, Richard, Keller, Elizabeth D., Parrenin, Frederic, Severinghaus, Jeffrey P., Vallelonga, Paul, Waddington, Edwin D., Winstrup, Mai
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: CONTINUOUS-FLOW ANALYSIS; HIGH-RESOLUTION RECORD; ABRUPT CLIMATE-CHANGE; ISOTOPIC COMPOSITION; WEST ANTARCTICA; AIR-CONTENT; SIPLE-DOME; WD2014 CHRONOLOGY; SHEET ELEVATIONS; GAS RECORDS; Antarc*; Antarctic; Antarctica; ice core; Ice Sheet; Roosevelt Island; Ross Sea; West Antarctica
• Online Access: https://curis.ku.dk/portal/da/publications/an-83-000yearold-ice-core-from-roosevelt-island-ross-sea-antarctica(97f08a98-bb38-4abd-aec3-9216d6f10552).html; https://doi.org/10.5194/cp-16-1691-2020; https://curis.ku.dk/ws/files/249104796/cp_16_1691_2020.pdf

In 2013 an ice core was recovered from Roosevelt Island, an ice dome between two submarine troughs carved by paleo-ice-streams in the Ross Sea, Antarctica. The ice core is part of the Roosevelt Island Climate Evolution (RICE) project and provides new information about the past configuration of the West Antarctic Ice Sheet (WAIS) and its retreat during the last deglaciation. In this work we present the RICE17 chronology, which establishes the depth-age relationship for the top 754m of the 763m core. RICE17 is a composite chronology combining annual layer interpretations for 0-343m (Winstrup et al., 2019) with new estimates for gas and ice ages based on synchronization of CH4 and delta O-18(atm) records to corresponding records from the WAIS Divide ice core and by modeling of the gas age-ice age difference. Novel aspects of this work include the following: (1) an automated algorithm for multiproxy stratigraphic synchronization of high-resolution gas records; (2) synchronization using centennial-scale variations in methane for preanthropogenic time periods (60-720 m, 1971 CE to 30 ka), a strategy applicable for future ice cores; and (3) the observation of a continuous climate record back to similar to 65 ka providing evidence that the Roosevelt Island Ice Dome was a constant feature throughout the last glacial period.