Instability of the East Antartic Ice Sheet during the Pliocene warmth?

上新世温暖期间东南南极冰盖不稳定？

基本信息

批准号：
NE/H014144/1
负责人：
Tina Van De Flierdt
金额：
$ 9.43万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FH014144%2F1
关键词：
Instability East Antartic Ice Sheet

项目摘要

Warming of the climate system is unequivocal, and evident from observations of increases in global average air and ocean temperatures. Based on projections published in the Nobel Peace Prize winning report of the Intergovernmental Panel on Climate Change in 2007, the Earth's surface is estimated to warm between 1.8 to 4.0 degree Celsius by the end of the century. Already now, we are observing the retreat of mountain glaciers, limited extent of sea ice in the Arctic Ocean, and melting around the edges of the polar ice caps in Greenland and parts of Antarctica. Projected sea level rise by 2100 ranges between 0.2 and 0.6 m. This range however does not include potential contributions from the ice caps, which today tie up a water mass equivalent to about 60-70 m of sea level change. From studying the climate in the past, we know that the polar ice caps can wax and wane with changing climatic conditions. The last time Earth climate was significantly warmer than today, for an extended amount of time, was 4.5 to 3 million years ago, during the time period of the Pliocene. Global temperatures in the warm Pliocene were about 3 degree Celsius higher than today. Sea level estimates for this time range from 5 to 40 m higher than today, with a most commonly used value around 25 m. Such an elevated sea level would not only mean the disappearance of the Greenland and West Antarctic ice sheets, but also instability in parts of the massive East Antarctic ice sheet. Data are however sparse, and models give conflicting results on whether melting only acted on the more vulnerable West Antarctic ice sheet, or also on parts of the large East Antarctic ice sheet. With our project we will try to address exactly this dilemma. We are going to analyse the chemical composition of ice-rafted sediments from the Southern Ocean off East Antarctica. This material was carried to its place of deposition by icebergs, and its geochemical fingerprint contained in mineral grains, allows us to track back the exact area of the continent where the iceberg was coming from. This in turn tells us which part of the ice margin became instable in the past. It is such evidence from the geological record that is vital to test and refine existing climate models. We will investigate which adjustments have to be made to climate models to reproduce our observational data. Once we succeed to produce a better database for understanding ice extent during the Pliocene warmth, and once we have a climate model that matches the observations of the past, we should have higher confidence to use the same type of model to foresee what may happen in the future.

气候系统变暖是明确的，从全球平均空气和海洋温度上升的观察中可以明显看出。根据政府间气候变化专门委员会2007年获得诺贝尔和平奖的报告中发布的预测，到本世纪末，地球表面预计将变暖1.8至4.0摄氏度。现在，我们已经观察到山地冰川的退缩、北冰洋海冰范围有限以及格陵兰岛和南极洲部分地区极地冰盖边缘的融化。预计到 2100 年海平面将上升 0.2 至 0.6 m。然而，这个范围不包括冰盖的潜在贡献，冰盖目前所容纳的水量相当于约 60-70 m 的海平面变化。通过对过去气候的研究，我们知道极地冰盖会随着气候条件的变化而增减。上一次地球气候在较长时间内明显比今天变暖是在 4.5 至 300 万年前的上新世时期。温暖的上新世全球气温比今天高出约 3 摄氏度。这次海平面估计比今天高 5 到 40 m，最常用的值约为 25 m。海平面如此升高不仅意味着格陵兰岛和西南极冰盖的消失，而且还意味着东南极冰盖部分地区的不稳定。然而，数据很少，而且关于融化是否只作用于更脆弱的南极西部冰盖，还是也作用于南极东部大冰盖的部分地区，模型给出了相互矛盾的结果。通过我们的项目，我们将尝试解决这个困境。我们将分析来自东南极洲附近南大洋的冰筏沉积物的化学成分。这种物质被冰山带到了沉积地，矿物颗粒中含有它的地球化学指纹，使我们能够追踪到冰山来自的大陆的确切区域。这反过来又告诉我们冰缘的哪一部分在过去变得不稳定。地质记录中的此类证据对于测试和完善现有气候模型至关重要。我们将调查必须对气候模型进行哪些调整才能重现我们的观测数据。一旦我们成功地建立了一个更好的数据库来了解上新世温暖期间的冰范围，并且一旦我们有了与过去的观测相匹配的气候模型，我们应该有更大的信心使用相同类型的模型来预测未来可能发生的情况未来。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica

上新世冰消事件时间线和东南极洲威尔克斯冰下盆地近海的生物地球化学响应

DOI：
10.1016/j.epsl.2018.04.054
发表时间：
2018-07-01
期刊：
Earth and Planetary Science Letters
影响因子：
5.3
作者：
Rachel A. Bertram;David J. Wilson;T. van de Flierdt;R. McKay;M. Patterson;F. Jiménez;C. Escutia;G. Duke;B. Taylor;C. Riesselman
通讯作者：
C. Riesselman

Glacial erosion of East Antarctica in the Pliocene: A comparative study of multiple marine sediment provenance tracers

上新世东南极洲冰川侵蚀：多种海洋沉积物来源示踪剂的比较研究