Offshore-onshore record of Last Glacial Maximum−to−present grounding line retreat at Pine Island Glacier, Antarctica

• Published in: Geology
• Main Authors: Nichols, Keir A., Rood, Dylan H., Venturelli, Ryan A., Balco, Greg, Adams, Jonathan, Guillaume, Louise, Campbell, Seth, Goehring, Brent M., Hall, Brenda L., Wilcken, Klaus, Woodward, John, Johnson, Joanne S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Geological Society of America 2023
• Subjects: Antarctic; West Antarctica; Pine Island Glacier; Antarc*; Antarctica; Ice Sheet; Pine Island
• Online Access: http://nora.nerc.ac.uk/id/eprint/534387/; https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51326.1/627644/Offshore-onshore-record-of-Last-Glacial-Maximum-to

Pine Island Glacier, West Antarctica, is the largest Antarctic contributor to global sea-level rise and is vulnerable to rapid retreat, yet our knowledge of its deglacial history since the Last Glacial Maximum is based largely on marine sediments that record a retreat history ending in the early Holocene. Using a suite of 10Be exposure ages from onshore glacial deposits directly adjacent to Pine Island Glacier, we show that this major glacier thinned rapidly in the early to mid-Holocene. Our results indicate that Pine Island Glacier was at least 690 m thicker than present prior to ca. 8 ka. We infer that the rapid thinning detected at the site furthest downstream records the arrival and stabilization of the retreating grounding line at that site by 8−6 ka. By combining our exposure ages and the marine record, we extend knowledge of Pine Island Glacier retreat both spatially and temporally: to 50 km from the modern grounding line and to the mid-Holocene, providing a data set that is important for future numerical ice-sheet model validation.