Collaborative Research:  New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches

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项目编号	1643868
	Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches
	Regina DeWitt
主持机构	East Carolina University
项目开始年	2017
	2017-09-01
项目结束日期	2020-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	271931(USD)
国家	美国
语种	英语
英文摘要	Nontechnical Description Glacier ice loss from Antarctica has the potential to lead to a significant rise in global sea level. One line of evidence for accelerated glacier ice loss has been an increase in the rate at which the land has been rising across the Antarctic Peninsula as measured by GPS receivers. However, GPS observations of uplift are limited to the last two decades. One goal of this study is to determine how these newly observed rates of uplift compare to average rates of uplift across the Antarctic Peninsula over a longer time interval. Researchers will reconstruct past sea levels using the age and elevation of ancient beaches now stranded above sea level on the low-lying coastal hills of the Antarctica Peninsula to determine the rate of uplift over the last 5,000 years. The researchers will also analyze the structure of the beaches using ground-penetrating radar and the characteristics of beach sediments to understand how sea-level rise and past climate changes are recorded in beach deposits. The benefits of these new records will be threefold: (1) they will help determine the natural variability of the Antarctic Ice Sheet and relative sea level (2) they will provide new insight about uplift and the structure of the Earth's interior; and 3) they will help researchers refine the methods used to determine the age of geologic deposits. The study results will be shared in outreach events at K-12 schools and with visitors of the Santa Barbara Natural History Museum. Three graduate students will be supported through this project. Technical description Paleo sea-level data is critical for reconstructing the size and extent of past ice sheets, documenting increased uplift following glacial retreat, and correcting gravity-based measurements of ice-mass loss for the impacts of post-glacial rebound. However, there are only 14 sites with relative sea-level data for Antarctica compared to over 500 sites used in a recent study of the North American Ice-Sheet complex. The purpose of this project is to use optically stimulated luminescence to date a series of newly discovered raised beaches along the eastern Antarctic Peninsula and an already known, but only preliminarily dated, series of raised beaches in the South Shetland Islands. Data to be collected at the raised beaches include the age and elevation, ground-penetrating radar profiles, and the roundness of cobbles and the lithology of ice-rafted debris. The study will test three hypotheses: (1) uplift rates have increased in modern times relative to the late Holocene across the Antarctic Peninsula, (2) the sea-level history at the northern tip of the Antarctic Peninsula is distinctly different than that of the South Shetland Islands, and (3) cobble roundness and the source of ice-rafted debris on raised beaches varied systematically through time reflecting the climate history of the northern Antarctic Peninsula.
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文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71799
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Regina DeWitt.Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches.2017.