Abstract Recent ice-mass loss driven by warming along the Antarctic Peninsula has resulted in rapid changes in uplift rates across the region. Are such events only a function of recent warming? If not, does the Earth response to such events last long enough to be preserved in Holocene records of relative sea level (RSL), and thus have a bearing on global-scale glacial isostatic adjustment (GIA) models (e.g. ICE-6G)? Answering such questions in Antarctica is hindered by the scarcity of RSL reconstructions within the region. Here, a new RSL reconstruction for Antarctica is presented based on beach ridges from Joinville Island on the Antarctic Peninsula. We find that RSL has fallen 4.9 ± 0.58 m over the past 3100 yr, and that the island experienced a significant increase in the rate of RSL fall from 1540 ± 125 cal. (calibrated) yr B.P. to 1320 ± 125 cal. yr B.P. This increase in the rate of RSL fall is likely due to the viscoelastic response of the solid Earth to terrestrial ice-mass loss from the Antarctic Peninsula, similar to the Earth response experienced after ice-mass loss following acceleration of glaciers behind the collapsed Larsen B ice shelf in 2002 C.E. Additionally, slower rates of beach-ridge progradation from 695 ± 190 cal. yr B.P. to 235 ± 175 cal. yr B.P. potentially reflect erosion of beach ridges from a RSL rise induced by a local glacial advance. The rapid response of the Earth to minor ice-mass changes recorded in the RSL record further supports recent assertions of a more responsive Earth to glacial unloading and at time scales relevant for GIA of Holocene and Pleistocene sea levels. Thus, current continental and global GIA models may not accurately capture the ice-mass changes of the Antarctic ice sheets at decadal and centennial time scales. 
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                            The Larsen Ice Shelf System, Antarctica (LARISSA): Polar Systems Bound Together, Changing Fast
                        
                    
    
            Climatic, cryospheric, and biologic changes taking place in the northern Antarctic Peninsula provide examples for how ongoing systemic change may pro‐ gress through the entire Antarctic system. A large, interdisciplinary research project focused on the Larsen Ice Shelf system, synthesized here, has documented dramatic ice cover, oceanographic, and ecosystem changes in the Antarctic Peninsula during the Holocene and the present period of rapid regional warming. The responsive- ness of the region results from its position in the climate and ocean system, in which a narrow continental block extends across zonal atmospheric and ocean flow, creating high snow accumulation, strong gradients and gyres, dynamic oceanography, outlet glaciers feeding into many fjords and bays having steep topography, and a continental shelf that contains many glacially carved troughs separated by areas of glacial sedi- ment accumulation. The microcosm of the northern Antarctic Peninsula has a tendency to change rapidly—rapid relative not just to Antarctica’s mainland but compared to the rest of the planet as well—and it is generally warmer than the rest of Antarctica. Both its Holocene and modern glaciological retreats offer a picture of how larger areas of Antarctica farther south might change under future warming. 
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                            - PAR ID:
- 10530117
- Publisher / Repository:
- Geological Society of America
- Date Published:
- Journal Name:
- GSA Today
- Volume:
- 29
- Issue:
- 8
- ISSN:
- 1052-5173
- Page Range / eLocation ID:
- 4 to 10
- Subject(s) / Keyword(s):
- Antarctica Larsen Ice Shelf Cryosphere Antarctic System Science
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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