EAPSI: Using geochemistry to unravel the history of an East Antarctic ice shelf system

EAPSI：利用地球化学揭示东南极冰架系统的历史

• 批准号: 1414755
• 负责人: Michelle Guitard
• 金额: $ 0.51万
• 依托单位: Guitard Michelle E
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1414755&HistoricalAwards=false
• 关键词: EAPSI; Using; geochemistry; unravel; history

Antarctica and the Southern Ocean play a central role in Earth's climate. To improve the climate models that predict changes in ice volume and sea level, it is important to understand factors affecting Antarctic ice mass balance. The geochemistry of three East Antarctic sediment cores may reveal how Antarctica's ice sheets fluctuated in the past. This research will be supervised by Dr. Yusuke Yokoyama, at the University of Tokyo. Necessary instruments and facilities, as well as Dr. Yokoyama's expertise in geochemistry make this an ideal research opportunity site.Reductions in Antarctic ice mass often co-occur with the presence of warm oceanic waters on the continental shelf, suggesting that ice shelf systems are sensitive to ocean temperatures. Identifying the sensitivity of ice shelves to ocean heat is critical for understanding ice sheet stability. Late Quaternary (125 ka-present) marine sediments collected in Prydz Bay, East Antarctica preserve evidence of ice shelf fluctuations. Three cores from Prydz Bay reveal at least four siliceous mud and ooze units interbedded with glacial marine units, representing open-marine conditions (ice-free) and glacial conditions (ice-covered), respectively. Alternating open-marine and glacial conditions suggest the Amery Ice Shelf system (AIS) in Prydz Bay has fluctuated through time. This research will examine this variation by measuring the relative abundance the isotope, beryllium 10 (10Be) in three Prydz Bay sediment cores. Relative abundance of 10Be is an indirect measurement of depositional environment; a higher abundance of 10Be indicates open-marine conditions. Establishing the depositional environment in Prydz Bay is essential to generating a more reliable late Quaternary AIS history. Unveiling the history of the largest outlet glacier in East Antarctica is relevant to concerns that climate change is destabilizing Antarctic ice sheets, with implications for future sea level rise. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.

南极洲和南大洋在地球气候中起着核心作用。为了改善预测冰量和海平面变化的气候模型，了解影响南极冰质量平衡的因素很重要。三个东南极沉积物岩心的地球化学可能揭示了南极的冰盖过去是如何波动的。这项研究将由东京大学的Yokoyama博士进行监督。 必要的工具和设施以及横山博士在地球化学方面的专业知识使它成为理想的研究机会站点。南极冰块的还原经常与大陆架上的温暖海洋水域共同发生，这表明冰架系统对海洋温度敏感。识别冰架对海热的敏感性对于理解冰盖稳定性至关重要。在南极洲东部Prydz湾收集的第四纪晚期（125 ka-tresent）海洋沉积物保留了冰架波动的证据。来自Prydz湾的三个核心揭示了至少四个硅质泥浆和渗入冰川海洋单元的底座，分别代表开放式海洋条件（无冰）和冰川条件（冰覆盖）。交替的开放陆地和冰川条件表明，普赖兹湾的杏仁冰架系统（AIS）随着时间的流逝而波动。这项研究将通过测量三个Prydz湾沉积物核中的同位素10（10BE）来检查这种变化。 10BE的相对丰度是对沉积环境的间接测量。较高的10BE丰度表示开放式陆地状况。在普莱兹湾建立沉积环境对于产生更可靠的第四纪AIS历史至关重要。揭示南极东部最大的出口冰川的历史与人们担心气候变化正在破坏南极冰盖的稳定，这对未来的海平面上升的影响。该NSF EAPSI奖与日本促进科学学会合作。