Oxygen Isotope Record from McMurdo Dome and its Relation to the Geological Climate Record of the Dry Valleys

本研究将从南维多利亚地泰勒谷头附近的一个小冰穹（“麦克默多穹”，约77 40′~ 77 50′，158 10′~ 159 20′′）获得覆盖全新世（最近1万年）和末次冰期最后一部分的稳定同位素气候记录。根据冰期-间冰期过渡深度调整的冰流模型和由氧同位素引起的沿岩心向下的积累速率变化，将推导出一个独立的时间尺度。将这种同位素代用气候记录与放射性碳代用气候记录进行比较，这些代用气候记录来自于栖息的三角洲、海岸线和冰碛，在附近的干谷中发现了一种双重方法，这种方法对于解释全新世期间在冰芯中观察到的氧同位素波动以及这段时间内的湖泊水位和冰缘位置至关重要。圆顶的位置就在横贯南极山脉的西面，预计对罗斯海冰盖的变化很敏感，但不受冰期-间冰期海平面上升的直接影响。通过与干谷冰川记录和Vostok、dome C和Byrd站冰芯的南极东部和西部长同位素剖面进行比较，可以揭示南极东部和西部冰盖对冰期-间冰期温度升高和海平面上升的响应。

This proposed research will obtain a stable isotope climate record covering the Holocene (the last 10,000 years) and the last part of the last glaciation from a small ice dome near the head of Taylor Valley, South Victoria Land ("McMurdo Dome" about 77 40' to 77 50'S, 158 10' to 159 20'E). An independent time scale will be derived from an ice-flow model adjusted to the depth of the glacial-interglacial transition and to oxygen isotope-derived variations in accumulation rate down the core. Comparison of this isotope proxy climate record with a radiocarbon-dated proxy record of climate, derived from perched deltas, strandlines and moraines, in the nearby Dry Valleys allows a dual approach that could be crucial for the interpretation of both the oxygen isotope fluctuations observed in ice cores during the Holocene and the lake levels and ice margin positions during this time span. The location of the dome, just west of the Transantarctic Mountains, is expected to have been sensitive to changes in ice cover of the Ross Sea, but protected against direct influences of glacial-interglacial sea level rise. The dome's isotope record may, when compared with the Dry Valley glacial record, and with long East and West Antarctic isotope profiles from ice cores at Vostok, Dome C and Byrd Station will reveal the response of the East and West Antarctic Ice Sheets to the glacial-interglacial temperature increase and sea level rise.