Ice thinning on nunataks during the glacial to interglacial transition in the Antarctic Peninsula region according to Cosmic-Ray Exposure dating: Evidence and uncertainties

Autor: Aster Team, Francisco Navarro, Julia García-Oteyza, Marc Oliva, Irene Schimmelpfennig, José M. Fernández-Fernández, David Palacios, Laëtitia Léanni
Přispěvatelé: Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Repositório da Universidade de Lisboa, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
010506 paleontology
Archeology
Nunatak
010504 meteorology & atmospheric sciences
Meltwater pulse 1A
01 natural sciences
Antarctic Cold Reversal
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
Deglaciation
Ice thinning
Glacial period
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology
[SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology
Ecology
Evolution
Behavior and Systematics
ComputingMilieux_MISCELLANEOUS
Hurd Peninsula ice cap
0105 earth and related environmental sciences
South Shetland Islands
Nuclide inheritance
Global and Planetary Change
geography
geography.geographical_feature_category
Geology
Last Glacial Maximum
Glacier
15. Life on land
Nunataks
13. Climate action
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology
Interglacial
Antarctica
Physical geography
Zdroj: Quaternary Science Reviews
Quaternary Science Reviews, 2021, 264, pp.107029. ⟨10.1016/j.quascirev.2021.107029⟩
Quaternary Science Reviews, Elsevier, 2021, 264, pp.107029. ⟨10.1016/j.quascirev.2021.107029⟩
Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP
ISSN: 0277-3791
DOI: 10.1016/j.quascirev.2021.107029⟩
Popis: International audience; The small ice caps distributed across the Antarctic Peninsula region have undergone large ice volume changes since the Last Glacial Cycle, in line with most of the Antarctic continent. While the surface extent of glacial shrinking is relatively well known, the timing of glacial oscillations and the magnitude of ice thinning remain little investigated. Cosmic-Ray Exposure (CRE) dating applied on ice-free vertical sequences can provide insights about the temporal framework of glacial oscillations. However, the potential occurrence of nuclide inheritance may overestimate the real timing of the last glacial retreat. This problem has been observed in many areas in Continental Antarctica, but similar studies have not yet been conducted in environments of the Maritime Antarctica, such as the South Shetland Islands (SSI). This research focuses on the Hurd Peninsula ice cap (HPIC, ca. 60 degrees 22' W, 62 degrees 40' S), located in the SW of Livingston Island, SSI. Past climate oscillations since the Last Glacial Cycle have determined the amount of ice stored in the ice cap. Today, this polythermal ice cap is surrounded by several nunataks standing out above the ice. Three of them have been selected to explore their deglaciation history and to test the potential occurrence of nuclide inheritance in deglaciated bedrocks associated with polythermal glaciers. We present a new dataset with 10 Be-10 exposure dates. Some of them were found to be anomalously old, evidencing that nuclide inheritance is present in bedrocks associated with polythermal ice caps and suggesting complex glacial exposure histories. We attribute this to limited erosion, given the gentle slope of the nunatak margins and the cold-based character of the surrounding ice. The remaining samples allowed to approach local surface-elevation changes of the HPIC. Our results suggest that ice thinning started during the Last Glacial Maximum (LGM) at similar to 22 ka but intense glacial shrinking occurred from similar to 18 to similar to 13 ka, when the nunataks became exposed, being particularly intense at the end of this period (similar to 14-13 ka) coinciding with the time of the meltwater pulse 1a (MWP-1a) and the end of the Antarctic Cold Reversal (ACR).
Databáze: OpenAIRE
Externí odkaz: