scholarly journals Variability in the freshwater balance of northern Marguerite Bay, Antarctic Peninsula: Results from δ18O

2008 ◽  
Vol 55 (3-4) ◽  
pp. 309-322 ◽  
Author(s):  
Michael P. Meredith ◽  
Mark A. Brandon ◽  
Margaret I. Wallace ◽  
Andrew Clarke ◽  
Melanie J. Leng ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Marguerite Bay ◽  
Freshwater Balance

High-concentration sediment plumes, Horseshoe Island, western Antarctic Peninsula

2021 ◽  
pp. 1-4
Author(s):  
CRISTIAN RODRIGO ◽  
ANDRÉS VARAS-GÓMEZ ◽  
ADRIÁN BUSTAMANTE-MAINO ◽  
EMILIO MENA-HODGES
Keyword(s):  
Antarctic Peninsula ◽  
Short Note ◽  
Sediment Concentration ◽  
Change Scenario ◽  
High Concentration ◽  
Tidewater Glaciers ◽  
Marguerite Bay ◽  
Southern Side ◽  
Reported Data ◽  
The Antarctic

The variability in sediment concentration and spatial distribution of meltwater discharges from tidewater glaciers can be used to elucidate climatic evolution and glacier behaviour due to the association between sediment yield and glacier retreat (e.g. Domack & McClennen 1996). In an accelerated deglaciation environment, higher sediment concentrations in the water column can change the glacimarine costal dynamics and affect productivity and sea floor ecosystems (e.g. Marín et al. 2013). In the Antarctic Peninsula Region, meltwater or turbid plumes were previously believed to be rare or without an important role in the sedimentary glacimarine environment (e.g. Griffith & Anderson 1989), but recent studies have shown that this is a common phenomenon in subpolar and transition polar climates (Yoo et al. 2015, Rodrigo et al. 2016). In the current climate change scenario, accelerated glacier retreats and mass losses can produce an increasing input of glacial meltwater into the fjord regions, a situation that is not yet well evaluated in the Antarctic Peninsula. In this short note, after in situ observation of an unusual waterfall from the southern side of the main western tidewater glacier (Shoesmith Glacier) of Horseshoe Island (Lystad Bay), Marguerite Bay (Fig. 1), we report high turbidity values associated with plumes from the glacier, whose values were higher than reported data from subpolar/transition polar Antarctic climates.

scholarly journals Recent dynamic changes on Fleming Glacier after the disintegration of Wordie Ice Shelf, Antarctic Peninsula

2018 ◽  
Vol 12 (4) ◽  
pp. 1347-1365 ◽  
Author(s):  
Peter Friedl ◽  
Thorsten C. Seehaus ◽  
Anja Wendt ◽  
Matthias H. Braun ◽  
Kathrin Höppner
Keyword(s):  
Antarctic Peninsula ◽  
Remote Sensing Data ◽  
Data Sets ◽  
Ice Shelf ◽  
Glacier Tongue ◽  
Marguerite Bay ◽  
Grounding Line ◽  
Continuous Dynamic ◽  
The 1960S ◽  
The Antarctic

Abstract. The Antarctic Peninsula is one of the world's regions most affected by climate change. Several ice shelves have retreated, thinned or completely disintegrated during recent decades, leading to acceleration and increased calving of their tributary glaciers. Wordie Ice Shelf, located in Marguerite Bay at the south-western side of the Antarctic Peninsula, completely disintegrated in a series of events between the 1960s and the late 1990s. We investigate the long-term dynamics (1994–2016) of Fleming Glacier after the disintegration of Wordie Ice Shelf by analysing various multi-sensor remote sensing data sets. We present a dense time series of synthetic aperture radar (SAR) surface velocities that reveals a rapid acceleration of Fleming Glacier in 2008 and a phase of further gradual acceleration and upstream propagation of high velocities in 2010–2011.The timing in acceleration correlates with strong upwelling events of warm circumpolar deep water (CDW) into Wordie Bay, most likely leading to increased submarine melt. This, together with continuous dynamic thinning and a deep subglacial trough with a retrograde bed slope close to the terminus probably, has induced unpinning of the glacier tongue in 2008 and gradual grounding line retreat between 2010 and 2011. Our data suggest that the glacier's grounding line had retreated by ∼ 6–9 km between 1996 and 2011, which caused ∼ 56 km2 of the glacier tongue to go afloat. The resulting reduction in buttressing explains a median speedup of ∼ 1.3 m d−1 (∼ 27 %) between 2008 and 2011, which we observed along a centre line extending between the grounding line in 1996 and ∼ 16 km upstream. Current median ice thinning rates (2011–2014) along profiles in areas below 1000 m altitude range between ∼ 2.6 to 3.2 m a−1 and are ∼ 70 % higher than between 2004 and 2008. Our study shows that Fleming Glacier is far away from approaching a new equilibrium and that the glacier dynamics are not primarily controlled by the loss of the former ice shelf anymore. Currently, the tongue of Fleming Glacier is grounded in a zone of bedrock elevation between ∼ −400 and −500 m. However, about 3–4 km upstream modelled bedrock topography indicates a retrograde bed which transitions into a deep trough of up to ∼ −1100 m at ∼ 10 km upstream. Hence, this endangers upstream ice masses, which can significantly increase the contribution of Fleming Glacier to sea level rise in the future.

Aerial dispersal of springtails on the Antarctic Peninsula: implications for local distribution and demography

2007 ◽  
Vol 19 (1) ◽  
pp. 3-10 ◽  
Author(s):  
T.C. Hawes ◽  
M.R. Worland ◽  
P. Convey ◽  
J.S. Bale
Keyword(s):  
Antarctic Peninsula ◽  
Potential Mechanism ◽  
Local Distribution ◽  
Aerial Dispersal ◽  
Wind Speeds ◽  
Terrestrial Arthropods ◽  
Marguerite Bay ◽  
Terrestrial Habitats ◽  
The Antarctic ◽  
Aerial Deposition

Aerial dispersal has been frequently proposed as a potential mechanism by which polar terrestrial arthropods are transported to, and settle the ice free habitats of Antarctica, but to date there has been little substantive evidence in support of this hypothesis. Using water traps we investigated aerial deposition of arthropods on Lagoon Island, Ryder Bay, on the Antarctic Peninsula. Over a period of five weeks, trapping at three different altitudes, we captured a total of nine springtails, Cryptopygus antarcticus, all alive. This is the first study to demonstrate conclusively the survival of wind-borne native arthropods within Antarctica. By scaling the modest trapping area and success against island surface area, it is clear that hundreds, if not thousands, of springtails are regularly relocated by winds between the terrestrial habitats of Marguerite Bay. We use known desiccation rates of C. antarcticus and wind speeds to predict the likelihood of successful dispersal between the principal terrestrial habitats of the larger Marguerite Bay. Implications for local and long-range dispersal are discussed in relation to C. antarcticus and other polar arthropods.

Cosmogenic 10Be exposure dating of glacial erratics on Horseshoe Island in western Antarctic Peninsula confirms rapid deglaciation in the Early Holocene

2019 ◽  
Vol 31 (6) ◽  
pp. 319-331 ◽  
Author(s):  
Attila Çiner ◽  
Cengiz Yildirim ◽  
M. Akif Sarikaya ◽  
Yeong Bae Seong ◽  
Byung Yong Yu
Keyword(s):  
Antarctic Peninsula ◽  
Late Quaternary ◽  
Western Antarctic Peninsula ◽  
Sea Levels ◽  
Exposure Dating ◽  
Ice Stream ◽  
Marguerite Bay ◽  
History Of ◽  
Cosmogenic 10Be ◽  
Exposure Ages

AbstractThe rapid warming observed in the western Antarctic Peninsula gives rise to a fast disintegration of ice shelves and thinning and retreat of marine-terminating continental glaciers, which is likely to raise global sea levels in the near future. In order to understand the contemporary changes in context and to provide constraints for hindcasting models, it is important to understand the Late Quaternary history of the region. Here, we build on previous work on the deglacial history of the western Antarctic Peninsula and we present four new cosmogenic 10Be exposure ages from Horseshoe Island in Marguerite Bay, which has been suggested as a former location of very fast ice stream retreat. Four samples collected from erratic pink granite boulders at an altitude of ~80 m above sea level yielded ages that range between 12.9 ± 1.1 ka and 9.4 ± 0.8 ka. As in other studies on Antarctic erratics, we have chosen to report the youngest erratic age (9.4 ± 0.8 ka) as the true age of deglaciation, which confirms a rapid thinning of the Marguerite Trough Ice Stream at the onset of Holocene. This result is consistent with other cosmogenic age data and other proxies (marine and lacustrine 14C and optically stimulated luminescence) reported from nearby areas.

An analysis of a 34-year air temperature record from Fossil Bluff (71°S, 68°W), Antarctica

1997 ◽  
Vol 9 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Stephen A. Harangozo ◽  
Steven R. Colwell ◽  
John C. King
Keyword(s):  
Air Temperature ◽  
Antarctic Peninsula ◽  
Surface Air Temperature ◽  
Temperature Record ◽  
West Antarctic ◽  
Air Temperatures ◽  
Marguerite Bay ◽  
First Time ◽  
Snow Temperature

An analysis of a long-term surface air temperature record for Fossil Bluff in the George VI Sound, West Antarctic Peninsula (WAP) documents in detail some important aspects of the climate of this area for the first time. The analysis identifies the close dependency of air temperatures on latitude in the WAP but reveals that the strength of this dependency is greatest in winter. This result along with others leads to the Fossil Bluff climate regime being characterized as ‘continental’ rather than ‘maritime’ as found further north. The WAP as a whole displays large interannual temperature variability but this is greatest in Marguerite Bay rather than the Fossil Bluff area. Evidence is also provided for secular climatic change appearing in summer throughout the WAP over the last few decades. The representativeness of existing Antarctic Peninsula annual air temperature climatologies, based mainly on snow temperature measurements, for the winter and summer periods is also noted.

scholarly journals Juvenile morphology of the large Antarctic canopy-forming brown alga, Desmarestia menziesii J. Agardh

Polar Biology ◽  
2019 ◽  
Vol 42 (11) ◽  
pp. 2097-2103 ◽  
Author(s):  
Frithjof C. Küpper ◽  
Charles D. Amsler ◽  
Simon Morley ◽  
Bruno de Reviers ◽  
Aurelia Reichardt ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Life Form ◽  
Research Station ◽  
Polar Regions ◽  
Marguerite Bay ◽  
Open Questions ◽  
Natural Range ◽  
The Antarctic ◽  
Adelaide Island ◽  
Desmarestia Menziesii

Abstract For many types of seaweeds in Polar Regions, open questions remain about how their life cycle contributes to their overall adaptation to the extreme abiotic environment. This applies in particular to the major canopy-forming brown algae in much of the Antarctic Peninsula of the genus Desmarestia, which was investigated here. Diving surveys around Rothera Research Station (Adelaide Island, Antarctica) during December 2017–February 2018 revealed the widespread presence of a hitherto-unknown life form of Desmarestia sp. of a tender, feather-like morphology. Further studies explored whether this could be (1) a new, hitherto undescribed Desmarestia species (2) a new record for the region of a known Desmarestia species previously recorded elsewhere or (3) a so-far unknown life form of a species recorded for the region. Collections enabled the extraction of PCR-friendly DNA and sequencing of ITS1, which unambiguously showed that the samples belonged to Desmarestia menziesii, the only Desmarestia species presently recorded for the Adelaide Island/Marguerite Bay region. The presence of the juvenile morphology was subsequently confirmed throughout much of the natural range of D. menziesii during cruise-based diving surveys along the Western Antarctic Peninsula in 2019 and from collections at Anvers Island in 1989. Our collections thus constitute its juvenile morphology, which is not previously documented in the literature. The wider significance for the Polar seaweeds is discussed in the context of Taxonomy and Ecology.

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