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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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This content will become publicly available on July 1, 2026
Insights into the sea-level history of the South Shetland Islands from ground penetrating radar on Livingston Island, Antarctica
Sea-level changes in polar environments are important for understanding the timing and magnitude of past ice-sheet changes. Most of the few records of such past sea-level changes in Antarctica are those derived from raised beach ridges. Many studies using raised beach ridges to reconstruct past sea levels across Antarctica commonly assume that they only record falling sea levels. However, their internal architecture may contain a record of other oscillations in relative sea-level (RSL) change. In this study, we examine the internal architecture of a well-developed set of raised beach ridges on Livingston Island of the Antarctic Peninsula using 10+ km of ground penetrating radar (GPR). Recalibrated published radiocarbon ages are used in combination with new optically stimulated luminescence (OSL) ages to compare beach morphology and stratigraphy to the glacial history of the region. Within this flight of raised beach ridges, evidence was found for both regressive and transgressive depositional patterns marked by progradational seaward dipping facies deposited during periods of RSL fall followed by erosion and deposition of landward dipping overwash and aggrading beds during interpreted periods of RSL rise. This succession is routinely located over a notch in the bedrock interpreted to represent a wave-cut feature. The ages of raised beach ridges underlain by wave-cut notches and composed of landward-dipping strata correlate with known Holocene ice advances at <500, ~2000, and ~5000 cal yrs BP. We propose that these transgressive phases are the result of glacial-isostatic adjustment (GIA). This GIA hypothesis further supports recent assertions of a much more dynamic RSL history for Antarctic coastlines, which may contaminate the Last Glacial Maximum RSL signal across Antarctica.
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- PAR ID:
- 10629186
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Quaternary Science Reviews
- Volume:
- 359
- Issue:
- C
- ISSN:
- 0277-3791
- Page Range / eLocation ID:
- 109363
- Subject(s) / Keyword(s):
- Sea level Antarctica glacial-isostatic adjustment optically stimulated luminescence rheology beach
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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