Late Quaternary climate variability as recorded by micropalaeontological diatom data and geochemical data in the western Ross Sea, Antarctica

2013 ◽  
Vol 25 (6) ◽  
pp. 804-820 ◽  
Author(s):  
R. Tolotti ◽  
C. Salvi ◽  
G. Salvi ◽  
M.C. Bonci
Keyword(s):  
Continental Slope ◽  
Ross Sea ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Geochemical Data ◽  
Flow Paths ◽  
Ice Flow ◽  
Quaternary Climate ◽  
History Of ◽  
Geochemical Analyses

AbstractCores acquired from the Ross Sea continental shelf and continental slope during the XXX Italian Programma Nazionale di Ricerche in Antartide (PNRA) were analysed and yielded interesting micropalaeontological, biostratigraphic diatom results and palaeoceanographic implications. These multi-proxy analyses enabled us to reconstruct the glacial/deglacial history of this sector of the Ross embayment over the last 40 000 years, advancing our understanding of the Last Glacial Maximum (LGM) environmental and sedimentological processes linked to the Ross Sea ice sheet/ice shelf fluctuations in a basin and continental-slope environment, and allowed us to measure some of the palaeoceanographic dynamics. The central sector of the Ross Sea and part of its coast (south of the Drygalski Ice Tongue) enjoyed open marine conditions in the pre-LGM era (27 500–24 000 years bp). The retreat of the ice sheet could have been influenced by a southward shift of a branch of the Ross gyre, which triggered early deglaciation at c. 18 600 cal bp with a significant Modified Circumpolar Deep Water inflow over the continental slope at c. 14 380 cal BP. We assume that a lack of depositional material in each core, although at different times, represents a hiatus. Other than problems in core collection, this could be due to the onset of modern oceanographic conditions, with strong gravity currents and strong High Salinity Shelf Water exportation. Moreover, we presume that improvements in biostratigraphy, study of reworked diatom taxa, and lithological and geochemical analyses will provide important constraints for the reconstruction of the LGM grounding line, ice-flow lines and ice-flow paths and an interesting tool for reconstructing palaeo-sub-bottom currents in this sector of the Ross embayment.

scholarly journals Late Quaternary paleoenvironment of the Ross Sea continental shelf, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 275-280 ◽  
Author(s):  
Akira Nishimura ◽  
Toru Nakasone ◽  
Chikara Hiramatsu ◽  
Manabu Tanahashi
Keyword(s):  
Organic Carbon ◽  
Marine Environment ◽  
Environmental Changes ◽  
Ross Sea ◽  
Late Quaternary ◽  
Sedimentary Environment ◽  
Sediment Cores ◽  
Ice Sheet ◽  
Ice Shelf ◽  
Accelerator Mass Spectrometer

Based on sedimenlological and micropaleontological work on three sediment cores collected at about 167° Ε in the western Ross Sea, Antarctica, and accelerator mass spectrometer l4C ages of organic carbon, we have reconstructed environmental changes in the area during the late Quaternary. Since 38 ka BP at latest, this area was a marine environment with low productivity. A grounded ice sheet advanced and loaded the sediments before about 30-25 ka BP. After 25 ka BP, the southernmost site (76°46'S) was covered by floating ice (shelf ice), preventing deposition of coarse terrigenous materials and maintaining a supply of diatom tests and organic carbon until 20 ka BP. The northernmost site (74°33'S) was in a marine environment with a moderate productivity influenced by shelf ice/ice sheet after about 20 ka BP. Since about 10 ka BP, a sedimentary environment similar to the present-day one has prevailed over this area.

Late Quaternary glacial and interglacial environments of the Nechako River - Cheslatta Lake area, central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 719-731 ◽  
Author(s):  
A Plouffe ◽  
V M Levson
Keyword(s):  
British Columbia ◽  
Late Quaternary ◽  
Late Glacial ◽  
Lake Area ◽  
Glacial Lakes ◽  
Ice Flow ◽  
Coast Mountains ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Quaternary History

The Quaternary stratigraphy of the Nechako River – Cheslatta Lake area of central British Columbia is described and interpreted to reconstruct the late Quaternary history of the region. Exposures of glacial and nonglacial sediments deposited prior to the last glaciation (Fraser) are limited to three sites. Pollen assemblages from pre-Fraser nonglacial sediments at two of these sites reveal forested conditions around 39 000 BP. During the advance phase of the Fraser Glaciation, glacial lakes were ponded when trunk glaciers blocked some tributary valleys. Early in the glaciation, the drainage was free in easterly draining valleys. Subsequently, the easterly drainage was blocked either locally by sediments and ice or as a result of impoundment of the Fraser River and its tributaries east of the study area. Ice generally moved east and northeast from accumulation zones in the Coast Mountains. Ice flow was influenced by topography. Major late-glacial lakes developed in the Nechako River valley and the Knewstubb Lake region because potential drainage routes were blocked by ice.

scholarly journals Formational history of the Wicklow Trough: a marine‐transgressed tunnel valley revealing ice flow velocity and retreat rates for the largest ice stream draining the late‐Devensian British–Irish Ice Sheet

2020 ◽  
Vol 35 (7) ◽  
pp. 907-919 ◽  
Author(s):  
Mark Coughlan ◽  
Zsuzsanna TÓth ◽  
Katrien J. J. Van Landeghem ◽  
Stephen Mccarron ◽  
Andrew J. Wheeler
Keyword(s):  
Flow Velocity ◽  
Ice Sheet ◽  
Ice Flow ◽  
Ice Stream ◽  
History Of

The local Last Glacial Maximum in McMurdo Sound, Antarctica: Implications for ice-sheet behavior in the Ross Sea Embayment

2019 ◽  
Vol 132 (1-2) ◽  
pp. 31-47 ◽  
Author(s):  
Andrew J. Christ ◽  
Paul R. Bierman
Keyword(s):  
Last Glacial Maximum ◽  
Ross Sea ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
Significant Advance ◽  
Ice Flow ◽  
Mcmurdo Sound ◽  
Last Glacial ◽  
Transantarctic Mountains ◽  
Western Ross Sea

AbstractDuring the Last Glacial Maximum (LGM), a grounded ice sheet filled the Ross Sea Embayment in Antarctica and deposited glacial sediments on volcanic islands and peninsulas in McMurdo Sound and coastal regions of the Transantarctic Mountains. The flow geometry and retreat history of this ice are debated, with contrasting views yielding divergent implications for the interaction between and stability of the East and West Antarctic ice sheets during late Quaternary time. Here, we present terrestrial geomorphologic evidence and reconstruct former ice-marginal environments, ice sheet elevations, and ice-flow directions in McMurdo Sound. Fossil algae in ice-marginal sediments provide a coherent radiocarbon chronology of maximum ice extent and deglaciation. We integrate these data with marine records to reconstruct grounded ice dynamics in McMurdo Sound and the western Ross Sea. The combined data set suggests ice flow toward the Transantarctic Mountains in McMurdo Sound during peak glaciation, with thick, grounded ice at or near its maximum position between 19.6 and 12.3 ka. Persistent grounded ice in McMurdo Sound and across the western Ross Sea after Meltwater Pulse 1a (14.0–14.5 ka) suggests that this sector of Antarctica did not significantly contribute to this rapid sea-level rise event. Our data show no significant advance of locally derived ice from the Transantarctic Mountains into McMurdo Sound during the local LGM.

Late Quaternary climate history of the Horton Plains, central Sri Lanka

2003 ◽  
Vol 22 (14) ◽  
pp. 1525-1541 ◽  
Author(s):  
Rathnasiri Premathilake ◽  
Jan Risberg
Keyword(s):  
Sri Lanka ◽  
Late Quaternary ◽  
Climate History ◽  
Quaternary Climate ◽  
History Of

Cenozoic Glacial and Tectonic History of the Transantarctic Mountains in the McMurdo Sound Region: Recent Progress from Drilling and Related Studies

Polar Record ◽  
1981 ◽  
Vol 20 (129) ◽  
pp. 543-548 ◽  
Author(s):  
P. J. Barrett ◽  
B. C. McKelvey
Keyword(s):  
Ross Sea ◽  
Ice Sheet ◽  
Ice Cover ◽  
Early History ◽  
Antarctic Ice Sheet ◽  
Ice Cap ◽  
Tectonic History ◽  
History Of ◽  
Transantarctic Mountains ◽  
East Antarctic Ice Sheet

Two of the outstanding problems in Antarctic earth sciences are the early history of the East Antarctic ice sheet, and the history of the Transantarctic Mountains. These two problems may well be linked, for if the initial uplift of the Transantarctic Mountains was sufficient to promote a permanent ice cap, this may have triggered formation of the East Antarctic ice sheet in the manner oudined by Drewry (1975, p 266). Glomar Challenger in 1973 made the first major breakthrough concerning early history of the ice sheet by recovering cores from the centre of the Ross Sea; they show that ice rafting began there 25 Ma BP and has been going on ever since (Hayes and others, 1975). However, the core data give little indication of the extent of ice cover, or of the climatic changes that led to expanded ice cover which produced the ice-rafted debris.

Progress report on the Antarctic ice sheet

Polar Record ◽  
1960 ◽  
Vol 10 (64) ◽  
pp. 3-10 ◽  
Author(s):  
G. de Q. Robin
Keyword(s):  
Sea Level ◽  
Ross Sea ◽  
Ice Sheet ◽  
Great Depth ◽  
Progress Report ◽  
The Other ◽  
The Past ◽  
History Of ◽  
Antarctic Continent ◽  
The Antarctic

The art, science and sport of conducting scientific traverses across the Antarctic continent has advanced so rapidly during the past decade that we are making considerable progress towards understanding the main characteristics of that continent and its ice mantle. Many reports of recent work are provisional, so some changes of detail in the following account may eventually prove necessary. Nevertheless, some major features are now well established, such as the great depth of the subglacial floor to the east of the Ross Sea, and the observations that show considerable sections of the rock of East Antarctica† to be above sea level. On the other hand, the past glaciological history of the continent and the state of the present mass balance of the ice sheet still need much more investigation before we can be satisfied with the answers. The continued activity in Antarctica should result in our knowledge of the continent advancing much further during the coming decade.

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