scholarly journals Development of a southern hemisphere subtropical wetland (Welsby Lagoon, south-east Queensland, Australia) through the last glacial cycle

2018 ◽  
Vol 202 ◽  
pp. 53-65 ◽  
Author(s):  
Haidee R. Cadd ◽  
John Tibby ◽  
Cameron Barr ◽  
Jonathan Tyler ◽  
Lilian Unger ◽  
...  
2004 ◽  
Vol 118-119 ◽  
pp. 23-53 ◽  
Author(s):  
J Shulmeister ◽  
I Goodwin ◽  
J Renwick ◽  
K Harle ◽  
L Armand ◽  
...  

2021 ◽  
Author(s):  
Tancrede Leger ◽  
Andrew Hein ◽  
Robert Bingham ◽  
Ángel Rodes ◽  
Derek Fabel

<p>The former Patagonian Ice Sheet was the most extensive Quaternary ice sheet of the southern hemisphere outside of Antarctica. Against a background of Northern Hemisphere-dominated ice volumes, it is essential to document how the Patagonian Ice Sheet and its outlet glaciers fluctuated throughout the Quaternary. This information can help us investigate the climate forcing mechanisms responsible for ice sheet fluctuations and provide insight on the causes of Quaternary glacial cycles at the southern mid-latitudes. Patagonia is part of the only continental landmass that fully intersects the precipitation-bearing Southern Westerly Winds and is thus uniquely positioned to study past climatic fluctuations in the southern mid-latitudes. While Patagonian palaeoglaciological investigations have increased, there remains few published studies investigating glacial deposits from the north-eastern sector of the former ice sheet, between latitudes 41°S and 46°S. Palaeoglaciological reconstructions from this region are required to understand the timing of Pleistocene glacial expansion and retreat, and to understand the causes behind potential latitudinal asynchronies in glacial advances throughout Patagonia. Here, we reconstruct the glacial history and chronology of a previously unstudied region of north-eastern Patagonia that formerly hosted the Río Corcovado (43°S, 71°W) palaeo ice-lobe. Here we present a new set of cosmogenic <sup>10</sup>Be exposure ages from presumed pre-LGM moraine boulder and glaciofluvial outwash surface cobble samples, establishing for the first time a comprehensive chronology for pre-LGM glacial margins of the Río Corcovado palaeo-glacier. This new dataset completes our effort to date the entire preserved moraine record of the Río Corcovado valley: which captures at least seven distinct Pleistocene glacial events. Our results allow answering questions on the timing of the maximum local ice extent of the last glacial cycle as well as older, pre-last glacial cycle glaciations, for which few robust glacier chronologies exist in the Southern Hemisphere. The most informative cosmogenic nuclide-derived glacial chronologies with the capacity to resolve questions on interhemispheric phasing of climate change require unambiguous dating of glacial margins spanning the entirety of the last glacial cycle and ideally earlier glacial cycles. Therefore, our findings have significant implications for understanding past climate fluctuations at the southern mid-latitudes, former Southern Westerly Winds behaviour and interhemispheric climate linkages throughout the Pleistocene. They also provide further evidence supporting the proposed latitudinal asynchrony in the timing of Patagonian Ice Sheet expansion during the last glacial cycle and enable novel glacio-geomorphological interpretations for the studied region.</p>


PAGES news ◽  
2001 ◽  
Vol 9 (2) ◽  
pp. 11-12 ◽  
Author(s):  
Sander Van der Kaars ◽  
P Kershaw ◽  
N Tapper ◽  
P Moss ◽  
C Turney

CATENA ◽  
2021 ◽  
Vol 206 ◽  
pp. 105252
Author(s):  
Miguel Bartolomé ◽  
Carlos Sancho ◽  
Gerardo Benito ◽  
Alicia Medialdea ◽  
Mikel Calle ◽  
...  

2021 ◽  
Vol 14 (2) ◽  
pp. 97-103
Author(s):  
Cécile L. Blanchet ◽  
Anne H. Osborne ◽  
Rik Tjallingii ◽  
Werner Ehrmann ◽  
Tobias Friedrich ◽  
...  

2018 ◽  
Vol 14 (11) ◽  
pp. 1819-1850 ◽  
Author(s):  
Olivier Cartapanis ◽  
Eric D. Galbraith ◽  
Daniele Bianchi ◽  
Samuel L. Jaccard

Abstract. Although it has long been assumed that the glacial–interglacial cycles of atmospheric CO2 occurred due to increased storage of CO2 in the ocean, with no change in the size of the “active” carbon inventory, there are signs that the geological CO2 supply rate to the active pool varied significantly. The resulting changes of the carbon inventory cannot be assessed without constraining the rate of carbon removal from the system, which largely occurs in marine sediments. The oceanic supply of alkalinity is also removed by the burial of calcium carbonate in marine sediments, which plays a major role in air–sea partitioning of the active carbon inventory. Here, we present the first global reconstruction of carbon and alkalinity burial in deep-sea sediments over the last glacial cycle. Although subject to large uncertainties, the reconstruction provides a first-order constraint on the effects of changes in deep-sea burial fluxes on global carbon and alkalinity inventories over the last glacial cycle. The results suggest that reduced burial of carbonate in the Atlantic Ocean was not entirely compensated by the increased burial in the Pacific basin during the last glacial period, which would have caused a gradual buildup of alkalinity in the ocean. We also consider the magnitude of possible changes in the larger but poorly constrained rates of burial on continental shelves, and show that these could have been significantly larger than the deep-sea burial changes. The burial-driven inventory variations are sufficiently large to have significantly altered the δ13C of the ocean–atmosphere carbon and changed the average dissolved inorganic carbon (DIC) and alkalinity concentrations of the ocean by more than 100 µM, confirming that carbon burial fluxes were a dynamic, interactive component of the glacial cycles that significantly modified the size of the active carbon pool. Our results also suggest that geological sources and sinks were significantly unbalanced during the late Holocene, leading to a slow net removal flux on the order of 0.1 PgC yr−1 prior to the rapid input of carbon during the industrial period.


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