Geomorphic implications of late Quaternary hydrological and climatic changes in the Northern Hemisphere tropics

Author(s):  
F. A. Street-Perrott ◽  
N. Roberts ◽  
S. Metcalfe
2010 ◽  
Vol 218 (1-2) ◽  
pp. 58-66 ◽  
Author(s):  
Zhou Shangzhe ◽  
Wang Jie ◽  
Xu Liubing ◽  
Wang Xiaoli ◽  
Patrick M. Colgan ◽  
...  

1997 ◽  
Vol 24 (5) ◽  
pp. 493 ◽  
Author(s):  
J. W. Winter

It is generally recognised that the distribution of vertebrates in rainforest and wet sclerophyll forest of the Wet Tropics region of north-eastern Australia is profoundly influenced by the formation of two rainforest refugia at the height of Pleistocene glacial periods. Anomalies in the distribution of non-volant mammals indicate that other events may be equally important. In this paper, past geographical occurrence of non-volant mammals is examined by equating the mammals’ known temperature tolerance with palaeoclimatic temperature zones. It is hypothesised that dispersal and vicariant phases taking place since the most recent glacial period have had a profound influence on current patterns of distribution. A major dispersal phase of cool-adapted species occurred after the glacial period, and continuous populations were subsequently fragmented into upland isolates by expansion of warm rainforest during the late post-glacial period. These upland isolates remain substantially unchanged to the present day. Species shared either with New Guinea or south-eastern Australia arrived in the region during the most recent post-glacial period. Clarification of periods of vicariance and dispersal provides a conceptual framework for testing relative divergences of populations within and between regions.


2004 ◽  
Vol 5 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
Andreas Fuhrmann ◽  
Thomas Fischer ◽  
Andreas Lücke ◽  
Achim Brauer ◽  
Bernd Zolitschka ◽  
...  

2020 ◽  
Author(s):  
Julius Jara-Muñoz ◽  
Amotz Agnon ◽  
Jens Fohlmeister ◽  
Jürgen Mey ◽  
Norbert Frank ◽  
...  

<p><span>High-resolution records of lake-level changes are crucial to elucidate the impact of local and global climatic changes in lacustrine basins. The Late Quaternary evolution of the Dead Sea has been characterized by substantial variability apparently linked with global climatic changes, beign subject of many research efforts since decades. Previous studies have defined two main lake phases, the Lake Lisan and the Dead Sea, the earlier was a highstand period that lasted between ~70 and ~15 ka, the  latter was the lowstand period that persisted until the present. Here we focus on the switch between Lake Lisan and Dead Sea studying fossil lake shorelines, a sequence that comprises dozens of levels exposed along the rims of the Dead Sea, containing abundant fossil stromatolites that we dated by mean of radiocarbon and U-decay series. We determined 90 radiocarbon and 35 U-Th ages from stromatolites from almost every shoreline level. We compared U-Th and radiocarbon ages to estimating a radiocarbon reservoir between 0.2 and 0.8 ka, used to correct the remaining radiocarbon ages before calibration. The resulting ages range between ~45  and ~20 ka. Dating was </span><span>complemented with analysis of stable oxygen and carbon isotopes. Furthermore, we applied a distributed hydrological balance model to constrain past precipitation and temperature conditions. Our results suggest that the duration of the last Lake Lisan highstand was shorter than previously estimated. Taking this at face value, the switch between Lake Lisan and Dead Sea occurred at ~28 ka, ~10 ka earlier than previously suggested. Oxygen and carbon isotopes show a consistent pattern, displaying a switch between wet and dry conditions at ~28 ka. Preliminary results from the hydrological model indicate a much stronger sensitivity of the lake level to precipitation amounts than to air temperature. From our results we can’t observe a clear link between global temperature variations and lake-level changes in the Lisan/Dead Sea lakes. Similar non-linear response to northern hemisphere climatic changes have been also documented in Holocene Dead Sea paleoclimatic records, suggesting that global climatic variations may led to variable lake-level responses. The results of this study adds further complexity to the understanding of factors controlling climate variability in the Dead Sea. </span></p>


Sign in / Sign up

Export Citation Format

Share Document