Wind-driven spreading of fresh surface water beneath ice shelves in the Eastern Weddell Sea

2014 ◽  
Vol 119 (6) ◽  
pp. 3818-3833 ◽  
Author(s):  
Q. Zhou ◽  
T. Hattermann ◽  
O. A. Nøst ◽  
M. Biuw ◽  
K. M. Kovacs ◽  
...  
Keyword(s):  
Surface Water ◽  
Weddell Sea ◽  
Ice Shelves ◽  
Fresh Surface ◽  
Eastern Weddell Sea

scholarly journals Modelling the impact of ocean warming on melting and water masses of ice shelves in the Eastern Weddell Sea

2010 ◽  
Vol 60 (3) ◽  
pp. 479-489 ◽  
Author(s):  
Malte Thoma ◽  
Klaus Grosfeld ◽  
Keith Makinson ◽  
Manfred A. Lange
Keyword(s):  
Ocean Warming ◽  
Weddell Sea ◽  
Water Masses ◽  
Ice Shelves ◽  
The Impact ◽  
Eastern Weddell Sea

scholarly journals Model for Submarine Glacial Deposition

1981 ◽  
Vol 2 ◽  
pp. 123-128 ◽  
Author(s):  
Olav Orheim ◽  
Anders Elverhøi
Keyword(s):  
Weddell Sea ◽  
Coarse Grained ◽  
Sedimentation Rates ◽  
Ice Shelf ◽  
Ice Shelves ◽  
Sedimentary Environments ◽  
Low Latitudes ◽  
Sediment Input ◽  
Eastern Weddell Sea

Present-day sedimentary environments in the eastern Weddell Sea confirm low clastic sediment input from wide (> 100 km) ice shelves. Mainly bioclastic sediments are formedin situon the inner and shallow central-shelf areas (250 to 350 m water depth), with sedimentation rates probably < 0.01 m ka−3. Ice-rafted debris (IRD) is mainly deposited on the outer shelf and upper continental slope, with a sedimentation rate of 0.02 to 0.07 m ka−3. The coarse-grained texture of these deposits is caused by removal of finer grades in suspension during settling of IRD sediments. Overconsolidated till was deposited < 31 ka BP during expansion of grounded ice to the shelf break. Subsequent eustatic rise caused grounded ice to float. Frozen-on sediments melted out of the base of the ice, depositing soft pebbly mud above the till. Marine conditions similar to present-day conditions were found for the interval 30 to 40 ka BP.IRD variation is an indicator of ice-shelf coverage and changes in relative sea-level, and is, in low latitudes, probably inversely related to the degree of ice cover.

The role of tides on the carbonate chemistry of a coastal polynya in the south-eastern Weddell Sea

2021 ◽  
Author(s):  
Elise Droste ◽  
Melchor González Dávila ◽  
Juana Magdalena Santana Casiano ◽  
Mario Hoppema ◽  
Gerd Rohardt ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Weddell Sea ◽  
Water Masses ◽  
Total Alkalinity ◽  
The South ◽  
Carbonate Chemistry ◽  
Large Variability ◽  
South Eastern ◽  
Coastal Polynya ◽  
Eastern Weddell Sea

&lt;p&gt;Tides have a large impact on coastal polynyas around Antarctica. We investigate the effect of semi-diurnal tidal cycles on the seawater carbonate chemistry in a coastal polynya hugging the Ekstr&amp;#246;m Ice Shelf in the south-eastern Weddell Sea. This region experiences some of the strongest tides in the Southern Ocean. We assess the implications for the contribution of coastal polynyas to the carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) air-sea flux of the Weddell Sea.&lt;/p&gt;&lt;p&gt;Two site visits, in January 2015 and January 2019, are intercompared in terms of the dissolved inorganic carbon (DIC) concentration, total alkalinity, pH, and CO&lt;sub&gt;2&lt;/sub&gt; partial pressure (pCO&lt;sub&gt;2&lt;/sub&gt;). The tides induce large variability in the carbonate chemistry of the coastal polynya in the austral summer: DIC concentrations vary between 2174 and 2223 umol kg&lt;sup&gt;-1&lt;/sup&gt;.&lt;/p&gt;&lt;p&gt;The tidal fluctuation in the DIC concentration can swing the polynya from a sink to a source of atmospheric CO&lt;sub&gt;2 &lt;/sub&gt;on a semi-diurnal timescale. We attribute these changes to the mixing of different water masses. The amount of variability induced by tides depends on &amp;#8211; and is associated with &amp;#8211; large scale oceanographic and biogeochemical processes that affect the characteristics and presence of the water masses being mixed, such as the rate of sea ice melt.&lt;/p&gt;&lt;p&gt;Sampling strategies in Antarctic coastal polynyas should always take tidal influences into account. This would help to reduce biases in our understanding of how coastal polynyas contribute to the CO&lt;sub&gt;2&lt;/sub&gt; uptake by the Southern Ocean.&lt;/p&gt;

Spatial distribution of Antarctic shrimps (Crustacea: Decapoda) by underwater photography

1991 ◽  
Vol 3 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Julian Gutt ◽  
M. Gorny ◽  
W. Arntz
Keyword(s):  
Spatial Distribution ◽  
Continental Shelf ◽  
Weddell Sea ◽  
Small Scale ◽  
Frequency Distributions ◽  
South Eastern ◽  
Direct Observations ◽  
Underwater Photography ◽  
Dispersion Patterns ◽  
Eastern Weddell Sea

Three species of shrimps (Notocrangon antarcticus, Chorismus antarcticus, Nematocarcinus lanceopes) were investigated in the south-eastern Weddell Sea using of underwater photography. Maximum densities of c. 100 specimens per 100 m2 were found for N. antarcticus on the continental shelf (200–600 m) and for N. lanceopes on the slope (800–1200 m). Small-scale dispersion patterns and size-frequency distributions were analyzed within dense concentrations. These direct observations indicate that the behaviour of the three species is adapted to different habitats with Chorismus distribution correlated with that of sponges and Notocrangon with base sediment.

scholarly journals Sea-Ice Investigations In The Weddell Sea During The German Antarctic Expedition 1979-80

1983 ◽  
Vol 4 ◽  
pp. 246-252 ◽  
Author(s):  
Joachim Schwarz
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Sea Ice ◽  
Young’S Modulus ◽  
Uniaxial Compressive Strength ◽  
Young's Modulus ◽  
Weddell Sea ◽  
Ice Shelves ◽  
Antarctic Expedition ◽  
Ice Conditions

In the austral winter of 1979-80, a German Antarctic expedition was sent by ship to the Filchner and Ronne ice shelves in order to find a suitable site for the establishment of a permanent Antarctic station. During this expedition, investigations were carried out on sea ice in the Weddell Sea in order to evaluate the accessibility of the site for icebreaking ships which are intended to convey construction materials to the site and, later on, to supply the station annually.This paper covers the results of investigations on sea-ice conditions during the voyage along the ice shelves from Cape Fiske (at the base of the Antarctic Peninsula) to Atka Bay with emphasis on sea-ice conditions in the area about 100 km north-west of Berkner Island (Fig.1.). In addition to the drift conditions (speed, direction), a special feature of multi-year sea ice is described. The main part of the paper deals with mechanical properties such as flexural strength, uniaxial compressive strength and Young’s modulus of columnar-grained sea ice from the southern border of the Weddell Sea. Salinities and temperatures were measured over the depth of the ice and used for calculating the flexural strength and the Young’s modulus of the ice. The uniaxial compressive strength was investigated as a function of strain-rate, brine volume and temperature on a closed-loop testing machine on samples which were carried back from Antarctica to Hamburg.

scholarly journals On the freshening of the northwestern Weddell Sea continental shelf

Ocean Science ◽  
2011 ◽  
Vol 7 (3) ◽  
pp. 305-316 ◽  
Author(s):  
H. H. Hellmer ◽  
O. Huhn ◽  
D. Gomis ◽  
R. Timmermann
Keyword(s):  
Sea Ice ◽  
Continental Shelf ◽  
Weddell Sea ◽  
Central Basin ◽  
Thermal Front ◽  
Late 20Th Century ◽  
Ice Shelves ◽  
Ice Retreat ◽  
Reduced Salt ◽  
Sea Ice Retreat

Abstract. We analyzed hydrographic data from the northwestern Weddell Sea continental shelf of the three austral winters 1989, 1997, and 2006 and two summers following the last winter cruise. During summer a thermal front exists at ~64° S separating cold southern waters from warm northern waters that have similar characteristics as the deep waters of the central basin of the Bransfield Strait. In winter, the whole continental shelf exhibits southern characteristics with high Neon (Ne) concentrations, indicating a significant input of glacial melt water. The comparison of the winter data from the shallow shelf off the tip of the Antarctic Peninsula, spanning a period of 17 yr, shows a salinity decrease of 0.09 for the whole water column, which has a residence time of <1 yr. We interpret this freshening as being caused by a combination of reduced salt input due to a southward sea ice retreat and higher precipitation during the late 20th century on the western Weddell Sea continental shelf. However, less salinification might also result from a delicate interplay between enhanced salt input due to sea ice formation in coastal areas formerly occupied by Larsen A and B ice shelves and increased Larsen C ice loss.

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