Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition

摘要(非技术性的)海平面上升是一个具有全球重要性的问题，它正日益影响着生活在海岸线上的数千万美国人。由于全球变暖，世界各地山区的冰川融化是海平面上升和沿海洪涝灾害增加的主要原因。然而，世界上最大的陆地冰盖位于极地地区，它们在持续变暖时的反应很难预测。这种不确定性的一个原因是缺乏对变暖条件下冰的行为和融化的观察，因为到目前为止，这是一种相对较新的全球气候状态，只持续了几代人。研究人员将利用埋藏在南极附近海底沙层和泥层中的地质档案，调查过去温暖条件下南极洲的冰生长情况。通过剥离海底下面的层，调查人员可以阅读影响冰盖的过去事件的历史书。位于南极的南极大陆拥有世界上最大的冰块。这位研究人员的发现将大大提高科学家对冰盖对全球变暖的反应及其对海平面上升的影响的理解。摘要(技术)陆基冰的融化正在抬高全球海平面，目前极地冰盖的贡献很小。然而，极地冰盖在气候变化中的未来作用是预测全球海平面上升的最关键的不确定性之一。最近的极地气候学测量没有很好地解决海洋和大气温室效应在冰盖上的各自作用，因为地球此时正在经历温室效应的极端上升。有关西南极冰盖演化的数据尤其稀少。为了解决这一数据差距，研究人员将重建南极冰层增长的时间和空间分布，通过最后一个温室到冰库的气候转变，大约37到33 Ma。他们将从高纬度古档案馆收集岩心样本的沉积学和地球化学数据，以追踪化学风化系统的关闭、冰川侵蚀、冰流和海冰的发展，因为东南极和西南极冰盖在韦德尔海地区合并。他们的发现将导致对温室压力在冰盖发展中的作用及其对全球气候系统的影响的理解的深刻增长。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Abstract (non-technical)Sea level rise is a problem of global importance and it is increasingly affecting the tens of millions of Americans living along coastlines. The melting of glaciers in mountain areas worldwide in response to global warming is a major cause of sea level rise and increases in nuisance coastal flooding. However, the world's largest land-based ice sheets are situated in the Polar Regions and their response under continued warming is very difficult to predict. One reason for this uncertainty is a lack of observations of ice behavior and melt under conditions of warming, as it is a relatively new global climate state lasting only a few generations so far. Researchers will investigate ice growth on Antarctica under past warm conditions using geological archives embedded in the layers of sand and mud under the sea floor near Antarctica. By peeling back at the layers beneath the seafloor investigators can read the history book of past events affecting the ice sheet. The Antarctic continent on the South Pole, carries the largest ice mass in the world. The investigator's findings will substantially improve scientists understanding of the response of ice sheets to global warming and its effect on sea level rise.Abstract (technical)The melt of land based ice is raising global sea levels with at present only minor contributions from polar ice sheets. However, the future role of polar ice sheets in climate change is one of the most critical uncertainties in predictions of sea level rise around the globe. The respective roles of oceanic and atmospheric greenhouse forcing on ice sheets are poorly addressed with recent measurements of polar climatology, because of the extreme rise in greenhouse forcing the earth is experiencing at this time. Data on the evolution of the West Antarctic ice sheet is particularly sparse. To address the data gap, researchers will reconstruct the timing and spatial distribution of Antarctic ice growth through the last greenhouse to icehouse climate transition around 37 to 33 Ma. They will collect sedimentological and geochemical data on core samples from a high-latitude paleoarchive to trace the shutdown of the chemical weathering system, the onset of glacial erosion, ice rafting, and sea ice development, as East and West Antarctic ice sheets coalesced in the Weddell Sea sector. Their findings will lead to profound increases in the understanding of the role of greenhouse forcing in ice sheet development and its effect on the global climate system.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.