Antarctic Ice Sheet Response to Global Pliocene Warmth

南极冰盖对全球上新世温暖的反应

• 批准号: 8918942
• 负责人: George Denton
• 金额: $ 24.99万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-06-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8918942&HistoricalAwards=false
• 关键词: Antarctic; Ice; Sheet; Response; Global

Current interpretations of glacial history in the Transantarctic Mountains permit two vastly opposing views of Pliocene Antarctic climate and associated ice response. One view, based on the semi-lithified Sirius Formation, calls for extensive ice-sheet collapse and warm (2-5 degrees C) marine flooding in East Antarctica, with Northfagus growing nearby. A contrasting view, based on isotopically dated unconsolidated Pliocene drifts, calls for mountain overriding by an expanded ice sheet under subantarctic climatic conditions. This investigation is designed to improve our understanding of Pliocene glacial history of the Transantarctic Mountains in order to reconcile these conflicting hypotheses. Field areas are in the Dry Valleys where all Pliocene glacial morphologic features and sedimentary units occur together with ashes from nearby volcanoes. These ashes will produce a precise Pliocene chronology by the new technology of laser fusion 40Ar/39Ar dating of single crystals. The resulting glacial and tectonic history should clarify existing conflicts of Pliocene climate and ice-sheet response. This will clarify the long-term mechanics of the global climate system (particularly near 2.4 Ma), and its effect on eustatic sea level, deep-sea oxygen isotope fluctuations, and the Antarctic response to global Pliocene warmth.

对南极洲外冰川历史的当前解释 山脉允许上新世南极洲的两种截然不同的观点 气候和相关的冰响应。 一种观点，基于 半石化的天狼星地层，需要大面积的冰盖 东部的崩塌和温暖（2-5摄氏度）的海洋洪水 南极洲，附近生长着北毛榉。 一个对比的观点， 根据同位素定年的松散上新世漂移， 呼吁山区覆盖的扩大冰盖下 亚南极气候条件 这次调查是为了 为了增进我们对上新世冰川历史的了解， 为了调和这些冲突， 假设 实地区域位于干旱山谷， 上新世冰川地貌特征及沉积单元 与附近火山的灰烬一起出现。 这些骨灰 将通过新技术制作出精确的上新世年表 激光聚变40 Ar/39 Ar定年单晶。 的 由此产生的冰川和构造历史应该澄清现有的 上新世气候和冰盖响应的冲突。 这 将阐明全球气候系统的长期机制 （特别是2.4Ma附近），以及它对海平面变化的影响， 深海氧同位素波动和南极的反应 上新世全球变暖的原因