Glacial development and temperature trends in the Antarctic and in South America

2020 ◽  
pp. 73-94
Author(s):  
J.H. Mercer
Keyword(s):  
South America ◽  
Temperature Trends ◽  
The Antarctic

Holocene glacier history of northeastern Cordillera Darwin, southernmost South America (55°S)

2021 ◽  
pp. 1-16
Author(s):  
Scott A. Reynhout ◽  
Michael R. Kaplan ◽  
Esteban A. Sagredo ◽  
Juan Carlos Aravena ◽  
Rodrigo L. Soteres ◽  
...  
Keyword(s):  
South America ◽  
Last Millennium ◽  
Glacial History ◽  
Dry Period ◽  
The North ◽  
Southward Shift ◽  
History Of ◽  
Glacial Expansion ◽  
The Antarctic ◽  
Glacial Advance

Abstract In the Cordillera Darwin, southernmost South America, we used 10Be and 14C dating, dendrochronology, and historical observations to reconstruct the glacial history of the Dalla Vedova valley from deglacial time to the present. After deglacial recession into northeastern Darwin and Dalla Vedova, by ~16 ka, evidence indicates a glacial advance at ~13 ka coeval with the Antarctic Cold Reversal. The next robustly dated glacial expansion occurred at 870 ± 60 calendar yr ago (approximately AD 1150), followed by less-extensive dendrochronologically constrained advances from shortly before AD 1836 to the mid-twentieth century. Our record is consistent with most studies within the Cordillera Darwin that show that the Holocene glacial maximum occurred during the last millennium. This pattern contrasts with the extensive early- and mid-Holocene glacier expansions farther north in Patagonia; furthermore, an advance at 870 ± 60 yr ago may suggest out-of-phase glacial advances occurred within the Cordillera Darwin relative to Patagonia. We speculate that a southward shift of westerlies and associated climate regimes toward the southernmost tip of the continent, about 900–800 yr ago, provides a mechanism by which some glaciers advanced in the Cordillera Darwin during what is generally considered a warm and dry period to the north in Patagonia.

scholarly journals A description and summary of the Antarctic Humpback Whale Catalogue

2020 ◽  
pp. 95-99
Author(s):  
Judith Allen ◽  
Carole Carlson ◽  
Peter T. Stevick
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Coast ◽  
Long Distance ◽  
Dorsal Fin ◽  
Feeding Area ◽  
The Antarctic

The Antarctic Humpback Whale Catalogue (AHWC) is an international collaborative project investigating movement patterns of humpback whales in the Southern Ocean and corresponding lower latitude waters. The collection contains records contributed by 261 researchers and opportunistic sources. Photographs come from all of the Antarctic management areas, the feeding grounds in southern Chile and also most of the known or suspected low-latitude breeding areas and span more than two decades. This allows comparisons to be made over all of the major regions used by  Southern Hemisphere humpback whales. The fluke, left dorsal fin/flank and right dorsal fin/flank collections represent 3,655, 413 and 407 individual whales respectively. There were 194 individuals resighted in more than one year, and 82 individuals resighted in more than one region. Resightings document movement along the western coast of South America and movement between the Antarctic Peninsula and western coast of South America and Central America. A single individual from Brazil was resighted off South Georgia, representing the first documented link between the Brazilian breeding ground and any feeding area. A second individual from Brazil was resighted off Madagascar, documenting long distance movement of a female between non-adjacent breeding areas. Resightings also include two matches between American Samoa and the Antarctic Peninsula, documenting the first known feeding site for American Somoa and setting a new long distance seasonal migration record. Three matches between Sector V and eastern Australia support earlier evidence provided by Discovery tags. Multiple resightings of individuals in the Antarctic Peninsula during more than one season indicate that humpback whales in this area show some degree of regional feeding area fidelity. The AHWC provides a powerful non-lethal and non-invasive tool for investigating the movements and population structure of the whales utilising the Southern Ocean Sanctuary. Through this methodical, coordinated comparison and maintenance of collections from across the hemisphere, large-scale movement patterns may be examined, both within the Antarctic, and from the Antarctic to breeding grounds at low latitudes.

New Neogene taxa of the tribe Chlamydini Teppner, 1922 (Pectinidae, Bivalvia) of southern South America

2019 ◽  
Vol 93 (06) ◽  
pp. 1088-1104
Author(s):  
María B. Santelli ◽  
Claudia J. del Río
Keyword(s):  
South America ◽  
Antarctic Circumpolar Current ◽  
Middle Miocene ◽  
South American ◽  
Southern South America ◽  
Southeastern Pacific ◽  
Previous Proposal ◽  
Circumpolar Current ◽  
The Antarctic ◽  
Middle Pliocene

AbstractThe Chilean species traditionally assigned to the genera Chlamys Röding, 1798 or Zygochlamys Ihering, 1907 are now placed in two new endemic South American taxa: Dietotenhosen n. gen. (middle Miocene–early middle Pliocene), to include the southeastern Pacific Ocean species D. hupeanus (Philippi, 1887) n. comb. and D. remondi (Philippi, 1887) n. comb., and Ckaraosippur n. gen. (earliest middle Miocene–Pliocene), for C. calderensis (Möricke, 1896) n. comb. (Chile) and C. camachoi n. sp. (Argentina). Both genera are the youngest survivors of the tribe Chlamydini in southern South America. None of them is related to the circumpolar genus Psychrochlamys Jonkers, 2003, and the previous proposal of the dispersal through the Antarctic Circumpolar Current for the species included herein in Dietotenhosen is rejected.UUID: http://zoobank.org/61b4bb50-321f-4b78-9069-609178ef0817

XIV.—The Cephalopoda of the Scottish National Antarctic Expedition

1912 ◽  
Vol 48 (2) ◽  
pp. 273-283 ◽  
Author(s):  
William Evans Hoyle
Keyword(s):  
South Africa ◽  
South America ◽  
Antarctic Expedition ◽  
The Antarctic

The Cephalopoda collected by the Scotia may, with a few trifling exceptions, be separated geographically into three divisions, coming respectively from South Africa, South America, and the Antarctic.

Zoogeography of the Antarctic ascidian fauna in relation to the sub-Antarctic and South America

2007 ◽  
Vol 19 (3) ◽  
pp. 321-336 ◽  
Author(s):  
Carmen Primo ◽  
Elsa Vázquez
Keyword(s):  
South America ◽  
Saint Paul ◽  
South American ◽  
South American Species ◽  
Species Classification ◽  
Antarctic Region ◽  
Antarctic Species ◽  
Tristan Da Cunha ◽  
Centre Of Origin ◽  
The Antarctic

AbstractThis study of the relationships between the Antarctic, sub-Antarctic and South America biogeographical regions used both existing and new data. We constructed a presence/absence matrix of 237 species for 27 biogeographical divisions which included the Amsterdam-Saint Paul and Tristan da Cunha islands. Species and areas were classified using cluster analysis combined with MDS ordination. Six main groups were obtained from the species classification: 1) Amsterdam-Saint Paul, and 2) Tristan da Cunha species, 3) species from the Macquarie Province, 4) species from the sub-Antarctic Region, 5) Antarctic species and species distributed in the cold regions, 6) South American species. The biogeographical components were dominated by the endemic (although it is not as high as in other groups), Antarctic-South America and Southern Hemisphere elements. Except for Amsterdam-Saint Paul, Tristan da Cunha and Bouvet, the areas considered were grouped together with Macquarie being rather related to New Zealand regions. We speculate that the Antarctic Region may have acted as an “evolutionary incubator”, providing a centre of origin for sub-Antarctic and South American ascidians.

New trigonioid bivalves from the Albian (Early Cretaceous) of Alexander Island, Antarctic Peninsula: systematics, paleoecology, and austral Cretaceous Paleobiogeography

1995 ◽  
Vol 69 (2) ◽  
pp. 264-279 ◽  
Author(s):  
Simon R. A. Kelly
Keyword(s):  
South America ◽  
East Africa ◽  
Antarctic Peninsula ◽  
Early Cretaceous ◽  
Southern South America ◽  
The Antarctic ◽  
Molluscan Assemblage ◽  
Faunal Similarity

Newly discovered trigonioid bivalves are systematically described from the Late Albian of the Fossil Bluff Group of Alexander Island, Antarctic Peninsula. The fauna includes Nototrigonia (Nototrigonia) ponticula Skwarko, N. (Callitrigonia) offsetensis n. sp., Eselaevitrigonia macdonaldi n. sp., Pterotrigonia (Pisotrigonia) capricornia (Skwarko), and Pacitrigonia praenuntians n. sp. It represents the first Albian trigonioid fauna described from the Antarctic. It is also the first published record of the Nototrigoniinae (excluding Pacitrigonia) outside Australasia. Paleoecologically, this fauna represents the shallowest and highest energy molluscan assemblage from the Fossil Bluff Group and occurs near the base of a significant transgressive unit, the Mars Glacier Member of the Neptune Glacier Formation. The paleogeography of Austral Cretaceous trigonioids is reviewed. Endemic centers are identified in India–east Africa, southern South America, and Australasia. Only one trigonioid genus, Pacitrigonia, had its origin in the Antarctic. During the earliest Cretaceous, cosmopolitan trigonioid genera occurred in Antarctica. In the mid-Cretaceous faunal similarity of Antarctica with Australasia was strong, and in the latest Cretaceous affinity with southern South America increased.

A new estimate of the adopted gravity value at Rothera Station, Antarctic Peninsula

1999 ◽  
Vol 11 (4) ◽  
pp. 461-462 ◽  
Author(s):  
Philip C. Jones ◽  
Julie K. Ferris
Keyword(s):  
South America ◽  
Antarctic Peninsula ◽  
Base Station ◽  
Falkland Islands ◽  
Gravity Station ◽  
Gravity Network ◽  
Scientific Station ◽  
The Uk ◽  
The Antarctic ◽  
Gravity System

Because of the lack of a definitive air link to an international gravity base station, the Antarctic Peninsula gravity network was originally, and still is, tied to the Potsdam gravity system via long ship links to South America (Renner 1981, Kennett 1965). An indirect link from the British Antarctic Survey (BAS) scientific station at Rothera to an International Gravity Standardisation Net 1971 (IGSN 71) base station in the UK had previously been made via a link to the BAS gravity station on the Falkland Islands in Port Stanley (McGibbon 1988). Whilst the apparent gravity difference between Port Stanley and the base station in the UK had been calculated via a two-way air tie using a LaCoste and Romberg meter (McGibbon 1988) and later strengthened with three two-way air ties using four LaCoste and Romberg meters (Bassett 1987), the link between Port Stanley and Rothera was based on a one-way tie that included a lengthy ship borne passage (McGibbon 1988). The weakness of this link insured that the adopted gravity value at Rothera continued to be based on the ship ties made by Griffiths et al. (1964) and Kennett (1965). This note describes the strengthening of the gravity link between Rothera and Port Stanley and the subsequent reassignment of the adopted gravity value at Rothera Station.

scholarly journals XXIX.—Turbellaria of the Scottish National Antarctic Expedition.

1907 ◽  
Vol 45 (3) ◽  
pp. 819-827 ◽  
Author(s):  
J. F. Gemmill ◽  
R. T. Leiper
Keyword(s):  
South America ◽  
Orkney Islands ◽  
Kerguelen Island ◽  
Antarctic Expedition ◽  
South Orkney Islands ◽  
The Antarctic

There were seven Turbellaria in the material handed to us by Mr W. S. Bruce, all obtained in April 1903 from Scotia Bay, South Orkney Islands (9–10 fms., Station 325, lat. 60° 44′ S., long. 44° 51′ W.). Their occurrence is interesting, as, although Studer (Ueber Seethiere aus dem Antarktischen Meere, 1876) mentions, without adequately describing it, a Eurylepta from Kerguelen Island, there are no definite records, so far as we have been able to ascertain, of Turbellarian species from nearer the Antarctic than the coasts of South America.

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