Radiocarbon ages of sorted circles on King George Island, South Shetland Islands, West Antarctica

2006 ◽  
Vol 18 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Gi Young Jeong
Keyword(s):  
Vegetation History ◽  
Sediment Cores ◽  
South Shetland Islands ◽  
King George Island ◽  
West Antarctica ◽  
Shetland Islands ◽  
Fine Grained ◽  
Plant Remains ◽  
Terrestrial Environments ◽  
History Of

Lichen and moss colonize the surface of glacial debris left after deglaciation. Transformation of unsorted debris into a sorted circle causes early plant remains to be preserved in the fine-grained centre encircled by a coarse, clastic border. Systematic radiocarbon dating of plant remains from the sorted stone circles on King George Island, South Shetland Islands, West Antarctica, yielded ages between 290–4710 14C yrs BP. The oldest age obtained from a large stone circle approximated the regional deglaciation age recorded in marine and lacustrine sediment cores. Most of the ages, however, underestimate the time of deglaciation due to the continual addition of younger plant remains, changes in soil motion, and the diverse vegetation history. Despite its current limitations as a terrestrial proxy for regional deglaciation, further systematic dating and careful interpretation based on surface processes may improve the usefulness of sorted circles in reconstructing the glacial and periglacial history of polar terrestrial environments.

scholarly journals Benthic molluscs collected in Western Antarctica during the “Caldas”, “Admiral Padilla” and “Admiral Campos” expeditions, southern summers 2014-2015, 2016-2017 and 2018-2019

2021 ◽  
Vol 50 (SuplEsp) ◽  
pp. 187-212
Author(s):  
Adriana Osorno ◽  
Jaime Cantera
Keyword(s):  
Taxonomic Diversity ◽  
South Shetland Islands ◽  
West Antarctica ◽  
Conservation Areas ◽  
Shetland Islands ◽  
History Of ◽  
Abundant Taxon ◽  
The Antarctic ◽  
Taxonomic Categories ◽  
Coastal Research

This research is part of the results of the three first expeditions of Colombia to West Antarctica and it focused on the systematics and taxonomic diversity of the benthic community of molluscs collected between 5 and 400 m deep. The Sampling sites where mollusks were collected were located along the Gerlache and Bransfield straits, around the Palmer Archipelago and the South Shetland Islands, adjacent to the Antarctic Peninsula. The list of identified species that are deposited in the Museum of Marine Natural History of Colombia - Makuriwa, of the Institute of Marine and Coastal Research “José Benito Vives de Andréis” -Invemar, is presented. This inventory consisted of 15 specimens distributed in 10 taxa, of which 7 were shelled gastropods (including 5 microgastropods) and 3 were bivalves. Four microgastropods were placed in greater taxonomic categories due to the low knowledge of these taxa in the region (Anatoma sp., Cingulopsoidea sp., Truncatelloidea sp. and Eatoniella sp.). The other gastropod species (3) were Margarella antarctica, Prosipho turritus and Nacella concinna. The bivalves found were Philobrya sublaevis, Adacnarca nitens and Thracia meridionalis. The identified species have previously been recorded in West Antarctica. Some of them, like the bivalves, show a circumantarctic distribution. Nacella concinna was the most abundant taxon. In coherence with the general objective of the “BioGerlache-Antarctica” project, the results generate contributions to the biological inventories of Antarctica, contributing to expand the information to define possible conservation areas in the future.

scholarly journals Morphology and variations of glacial drainage basins in the King George Island ice field, Antarctica

1999 ◽  
Vol 29 ◽  
pp. 220-224 ◽  
Author(s):  
Jefferson C. Simões ◽  
Ulisses F. Bremer ◽  
Francisco E. Aquino ◽  
Francisco A. Ferron
Keyword(s):  
South Shetland Islands ◽  
Field Observations ◽  
Multispectral Imagery ◽  
King George Island ◽  
West Antarctica ◽  
Drainage Basins ◽  
Shetland Islands ◽  
Radio Echo Sounding ◽  
Ice Field ◽  
Glacial Cover

AbstractA Système probatoire pour l’observation de la terre (SPOT) mosaic of King George Island, the largest (1250 Km2) of the South Shetland Islands, West Antarctica, shows its major morphological features. Three main ice domes and 70 glacier drainage basins, covering 92.7% of the King George Island area, strongly controlled by the subglacial morphology and drained by relatively fast-moving tidewater outlet glaciers, were delineated. A general retreat of ice fronts through four decades, more intensely on the eastern side of the island (to the Bransfield Strait), resulted in the loss of about 7% of the glacial cover area. Superficial snow fades were derived from SPOT multispectral imagery and, together with field observations, allowed the transient-snowline elevation to be obtained The latter is estimated to have risen from about 200-250 m in the mid-1950s to 300-350 m by 1988. Spot radio-echo sounding surveys give an overview of the bedrock morphology.

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