Stable Isotope Studies at East Antarctic US ITASE Sites

该奖项支持一个从南极东部浅(100米)冰芯获取稳定同位素剖面的项目，以增加在“ITASE”(国际横贯北极科学考察)计划支持下收集的环境替代数据的不断增长的数据库。在南极洲，气候的仪器记录特别短(约40年，除了沿海的几个孤立地点)，而冰芯代理数据是将这一记录延续到过去的唯一手段。使用来自冰芯的水的稳定同位素(18-O/16-O和D/H比值)作为温度的替代物，无论是在很短的时间尺度(即季节性的)还是在很长的时间尺度(数百年、几千年)都得到了很好的证实。利用多元回归方法和西南极的浅冰芯，重建了南极近150年来的气候，表明南极大陆平均以0.2K/世纪的速度变暖。进一步改进这些重建是进一步扩大美国ITASE项目的主要动机。将从东南极的维多利亚大陆获得10到15个浅层(~100米)并进行分析。核心将沿着一条横穿的路线收集，从泰勒穹顶开始，到南极结束。岩心的年龄-深度关系将通过稳定同位素、视觉地层学和季节性化学特征和标志层的组合来确定。从这些岩心获得的南极气候重建将被纳入全球古气候信息网络，这在科学、政策和教育方面具有重要意义。该项目将包括研究生和博士后培训以及实地经验。

This award supports a project to obtain stable isotope profiles from shallow (100 m) ice cores from East Antarctica, to add to the growing database of environmental proxy data collected under the auspices of the "ITASE" (International TransAntarctic Scientific Expedition) program. In Antarctica, the instrumental record of climate is particularly short (~40 years except in a few isolated locations on the coast), and ice core proxy data are the only means available for extending this record into the past. The use of stable isotopes of water (18-O/16-O and D/H ratios) from ice cores as proxies for temperature is well established for both very short (i.e. seasonal) and long timescales (centuries, millennia). Using multivariate regression methods and shallow ice cores from West Antarctica, a reconstruction of Antarctic climate over the last ~150 years has been developed which suggests the continent has been warming, on average, at a rate of ~0.2 K/century. Further improving these reconstructions is the chief motivation for further extending the US ITASE project. Ten to fifteen shallow (~ 100 m) from Victoria Land, East Antarctica will be obtained and analyzed. The core will be collected along a traverse route beginning at Taylor Dome and ending at the South Pole. Age-depth relationships for the cores will be determined through a combination of stable isotopes, visual stratigraphy and seasonal chemical signatures and marker horizons. Reconstructions of Antarctic climate obtained from these cores will be incorporated into the global network of paleoclimate information, which has been important in science, policy and educational contexts. The project will include graduate student and postdoctoral training and field experience.