scholarly journals Initial reconnaissance for a South Georgia ice core

2016 ◽  
Vol 62 (231) ◽  
pp. 54-61 ◽  
Author(s):  
P. A. MAYEWSKI ◽  
A. KULI ◽  
G. CASASSA ◽  
M. ARÉVALO ◽  
D. A. DIXON ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Ice Core ◽  
South Atlantic ◽  
Basic Information ◽  
The South ◽  
Preliminary Step ◽  
South Georgia ◽  
Lower Elevation ◽  
Ice Core Record ◽  
Ice Radar

ABSTRACTWe present the first snow/ice chemistry and ice radar results ever collected from South Georgia as part of an initial reconnaissance with the ultimate goal of assessing the feasibility of a South Georgia ice core to reconstruct past climate in the South Atlantic. South Georgia is well situated to capture a record of past atmospheric chemical composition over the South Atlantic and of past variability in the position and intensity of the austral westerlies. The question is how well preserved an ice core record can be recovered from a region experiencing accelerated melting? The results presented in this paper offer only a preliminary step in determining the feasibility of future deep ice coring on South Georgia. However, this initial reconnaissance does provide some basic information including: the chemistry of the atmosphere over South Georgia relative to other Southern Hemisphere ice coring sites; the potential for preservation of ‘annual layers’ in old ice on the island; a possible age for deep ice in the region; and an estimate of glacier health in the lower elevation regions of the island.

Bycatch of fish in the South Atlantic krill fishery

1992 ◽  
Vol 4 (4) ◽  
pp. 389-392 ◽  
Author(s):  
Inigo Everson ◽  
Alexei Neyelov ◽  
Yuri E Permitin
Keyword(s):  
South Atlantic ◽  
Open Ocean ◽  
Research Vessel ◽  
The South ◽  
South Georgia

Icefish (Champsocephalus) were taken as bycatch during krill fishing operations from a research vessel. The data indicate that the bycatch of fish in the commercial krill fishery may be significant in some areas of the South Georgia shelf. The problem is thought to be least in open ocean krill fishing.

Millennial-scale climate changes on South Georgia, Southern Ocean

2003 ◽  
Vol 59 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Gunhild C. Rosqvist ◽  
Pernilla Schuber
Keyword(s):  
Southern Hemisphere ◽  
North Atlantic ◽  
Climate Changes ◽  
South Atlantic ◽  
The South ◽  
Temperature Changes ◽  
South Georgia ◽  
The North ◽  
Suitable Site ◽  
Millennial Scale

AbstractThe location of South Georgia (54°S, 36°W) makes it a suitable site for the study of the climatic connections between temperate and polar environments in the Southern Hemisphere. Because the mass balance of the small cirque glaciers on South Georgia primarily responds to changes in summer temperature they can provide records of changes in the South Atlantic Ocean and atmospheric circulation. We use grey scale density, weight-loss-on-ignition, and grain size analyses to show that the proportion of glacially eroded sediments to organic sediments in Block Lake was highly variable during the last 7400 cal yr B.P. We expect that the glacial signal is clearly detectable above noise originating from nonglacial processes and assume that an increase in glacigenic sediment deposition in Block Lake has followed Holocene glacier advances. We interpret proglacial lake sediment sequences in terms of summer climate warming and cooling events. Prominent millennial-scale features include cooling events between 7200 and 7000, 5200 and 4400, and 2400 and 1600 cal yr B.P. and after 1000 cal yr B.P. Comparison with other terrestrial and marine records reveals that the South Georgian record captures all the important changes in Southern Hemisphere Holocene climate. Our results reveal a tentative coupling between climate changes in the South Atlantic and North Atlantic because the documented temperature changes on South Georgia are anti-phased to those in the North Atlantic.

scholarly journals Geophysical Investigations Of The Tropical Quelccaya Ice Cap, Peru

1982 ◽  
Vol 28 (98) ◽  
pp. 57-69 ◽  
Author(s):  
L. G. Thompson ◽  
J. F. Bolzan ◽  
H. H. Brecher ◽  
P. D. Kruss ◽  
E. Mosley-Thompson ◽  
...  
Keyword(s):  
Ice Core ◽  
Topographic Map ◽  
Outlet Glacier ◽  
Tropical Glaciers ◽  
Ice Cap ◽  
Ice Core Record ◽  
Geophysical Investigations ◽  
Quelccaya Ice Cap ◽  
Radar Sounder ◽  
Ice Radar

Abstract During the 1978 and 1979 field seasons, ice thicknesses on the Quelccaya ice cap were determined using a Worden geodetic gravity meter along a west–east traverse and using a mono–pulse ice radar sounder along a north–south traverse. The maximum ice thickness measured was 180 ± 10 m. Based upon the known thickness of the ice cap and the net accumulation, depth–age calculations indicate that an ice core record covering at least the past 600 years and perhaps 1 300 years could be obtained from this tropical ice cap. A topographic map of the Qori Kalis glacier (the largest outlet glacier from the Quelccaya ice cap) has been compiled at a scale of 1:6 000 from 1963 aerial photography. Terrestrial photography of the glacier was obtained in 1978 and coordinates of the edge of the glacier were determined photogrammetrically. Comparison of these two shows that over this 15 year period the glacier has thinned with the terminus retreating more than 100 m. The retreat measured for the Qori Kalis glacier is consistent with the behavior of other tropical glaciers.

3. The Geological Relations of South Georgia

1914 ◽  
Vol 1 (2) ◽  
pp. 61-64
Author(s):  
J. W. Gregory
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Special Interest ◽  
South Atlantic ◽  
Geological History ◽  
The South ◽  
Northern Margin ◽  
South Georgia ◽  
The Andes ◽  
History Of

The special interest of the island of South Georgia depends on the evidence it promises as to the geological history of that part of the Southern Ocean which lies south of the South Atlantic. According to the well-known views of Professor Suess, South Georgia is on a continuation of the mountain line of the Andes, which at the southern end of South America bends eastward along the northern margin of Drake's Sea and continues 30° to the east, where it turns southward; it completes a great horseshoe-shaped course by passing through South Georgia and returning westward through the South Orkneys to Grahamland.

XXIV.—The Geological Relations and Some Fossils of South Georgia.

1916 ◽  
Vol 50 (4) ◽  
pp. 817-824 ◽  
Author(s):  
J. W. Gregory
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Special Interest ◽  
South Atlantic ◽  
Metamorphic Rocks ◽  
The South ◽  
South Georgia ◽  
The Andes ◽  
Pass Through

The special interest of South Georgia depends on its evidence regarding the geology of the part of the Southern Ocean which lies south of the South Atlantic. According to Professor Suess, the island is an extension of the Andes, which, at the southern end of South America, turn eastward, and by a great horse-shoe-shaped curve pass through South Georgia to the South Orkneys and Graham Land.The geology of South Georgia is but little known. Thürach † described the island as consisting of metamorphic rocks, ranging from granular gneiss to clay-slate, and of diabase tuff.

Abrupt Cooling of Antarctic Surface Waters and Sea Ice Expansion in the South Atlantic Sector of the Southern Ocean at 5000 cal yr B.P.

2001 ◽  
Vol 56 (2) ◽  
pp. 191-198 ◽  
Author(s):  
David A. Hodell ◽  
Sharon L. Kanfoush ◽  
Aldo Shemesh ◽  
Xavier Crosta ◽  
Christopher D. Charles ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Surface Waters ◽  
Climate Changes ◽  
Ice Core ◽  
South Atlantic ◽  
The South ◽  
Atlantic Sector ◽  
Middle Holocene ◽  
The North

AbstractAntarctic surface waters were warm and ice free between 10,000 and 5000 cal yr B.P., as judged from ice-rafted debris and microfossils in a piston core at 53°S in the South Atlantic. This evidence shows that about 5000 cal yr B.P., sea surface temperatures cooled, sea ice advanced, and the delivery of ice-rafted detritus (IRD) to the subantarctic South Atlantic increased abruptly. These changes mark the end of the Hypsithermal and onset of Neoglacial conditions. They coincide with an early Neoglacial advance of mountain glaciers in South America and New Zealand between 5400 and 4900 cal yr B.P., rapid middle Holocene climate changes inferred from the Taylor Dome Ice Core (Antarctica), cooling and increased IRD in the North Atlantic, and the end of the African humid period. The near synchrony and abruptness of all these climate changes suggest links among the tropics and both poles that involved nonlinear response to gradual changes in Northern Hemisphere insolation. Sea ice expansion in the Southern Ocean may have provided positive feedback that hastened the end of the Hypsithermal and African humid periods in the middle Holocene.

The Mud-Dwelling Hydrozoan Boreohydra simplex in the Western North Atlantic

1974 ◽  
Vol 31 (10) ◽  
pp. 1666-1667
Author(s):  
Dale R. Calder
Keyword(s):  
North Atlantic ◽  
South Atlantic ◽  
The South ◽  
Eastern Canada ◽  
South Georgia ◽  
The North ◽  
The North Atlantic

Boreohydra simplex was collected at a depth of 400 m in Cabot Strait, eastern Canada; this solitary, mud-dwelling hydroid is previously unreported from the western North Atlantic. Elsewhere, it has been found along the coasts of Scandinavia, Britain, and Iceland in the North Atlantic, and from South Georgia in the South Atlantic.

scholarly journals Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene

2018 ◽  
Author(s):  
Zoë Thomas ◽  
Richard T. Jones ◽  
Chris Fogwill ◽  
Jackie Hatton ◽  
Alan Williams ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Late Holocene ◽  
Ice Core ◽  
South Atlantic ◽  
Falkland Islands ◽  
The South ◽  
Pressure System ◽  
Amundsen Sea ◽  
Atlantic Sector ◽  
Synoptic Conditions

Abstract. The Amundsen Sea Low (ASL) plays a major role in modulating the climate and environment of Antarctica and is of global importance in the Earth system. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen Seas prior to the satellite era (post-1979) limits our understanding of past behaviour and impact of the ASL. The limited proxy evidence for changes in the ASL are primarily limited to the Antarctic where ice core evidence suggests a deepening of the atmospheric pressure system during the late Holocene. However, no data has previously been reported from the northern side of the ASL. Here we report a high-resolution, multi-proxy study of a 5000 year-long peat record from the Falkland Islands (South Atlantic sector of the Southern Ocean), an area sensitive to contemporary ASL dynamics. In combination with climate reanalysis, we find a marked period of wetter, colder conditions most likely the result of enhanced southerly airflow between 5000 and 2500 years ago, and inconsistent with synoptic conditions associated with the ASL today. After 2500 years ago, drier and warmer conditions were established, implying more westerly airflow and the increased projection of the ASL onto the South Atlantic. Our results are in agreement with Antarctic ice core records and suggest the Falkland Islands provide a valuable location for reconstructing atmospheric circulation changes across a large sector of the Southern Ocean on multi-decadal to millennial timescales. The possible role of tropical Pacific in establishing contemporary-like synoptic circulation is explored.

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