Cosmogenic nuclide constraints on late Quaternary glacial chronology on the Dalijia Shan, northeastern Tibetan Plateau

2013 ◽  
Vol 79 (3) ◽  
pp. 439-451 ◽  
Author(s):  
Jie Wang ◽  
Christine Kassab ◽  
Jonathan M. Harbor ◽  
Marc W. Caffee ◽  
Hang Cui ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Last Glacial Maximum ◽  
Younger Dryas ◽  
Glacial Maximum ◽  
The Tibetan Plateau ◽  
Last Glacial ◽  
Cosmogenic Nuclide ◽  
Mis 3 ◽  
Northeastern Tibetan Plateau ◽  
Exposure Ages

AbstractCosmogenic nuclide (CN) apparent exposure dating has become a widely used method for determining the age of glacial landforms on the Tibetan Plateau with > 1200 published ages. We present the first 10Be exposure ages from the Dalijia Shan, the most northeastern formerly glaciated mountain range on the Tibetan Plateau. The moraine groups identified from field and remote sensing imagery mapping record four glacial events at 37.07 ± 3.70 to 52.96 ± 4.70 ka (MIS 3), 20.17 ± 1.79 to 26.99 ± 2.47 ka (MIS 2), 16.92 ± 1.49 to 18.76 ± 1.88 ka (MIS 2), and 11.56 ± 1.03 to 11.89 ± 1.06 ka (Younger Dryas). These ages indicate that glaciation in the northeastern Tibetan Plateau is much younger than previously thought. In addition, this record is consistent with many other regions on the Tibetan Plateau, with a local last glacial maximum during MIS 3 asynchronous with Northern Hemisphere last glacial maximum during MIS 2. The Dalijia Shan might also include an event of Younger Dryas age, but this needs to be tested in future studies.

Marine Isotope Stage 3 paleotemperature inferred from reconstructing the Die Shan ice cap, northeastern Tibetan Plateau

2018 ◽  
Vol 89 (2) ◽  
pp. 494-504 ◽  
Author(s):  
Hang Cui ◽  
Jie Wang ◽  
Beibei Yu ◽  
Zhenbo Hu ◽  
Pan Yao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Marine Isotope Stage ◽  
The Tibetan Plateau ◽  
Equilibrium Line Altitude ◽  
Last Glacial ◽  
Mis 3 ◽  
Ice Cap ◽  
Northeastern Tibetan Plateau

AbstractGlacial extent mapping and dating indicate that the local last glacial maximum (LLGM) of the northeastern Tibetan Plateau occurred during mid-Marine Isotope Stage (MIS) 3. This is asynchronous with the global last glacial maximum (LGM) that occurred during MIS 2. The causes underlying this asynchronicity are the subject of ongoing debate, and paleoclimatic reconstructions are a key to advancing understanding of the climatic influence on the spatial and temporal patterns of paleoglaciation. We used multiple methods to reconstruct the equilibrium-line altitude (ELA) of the Die Shan paleo-ice cap on the northeastern Tibetan Plateau, and to infer past temperature for ice maximum positions believed to be mid-MIS 3 in age, based on regional correlation. Geomorphic ELA reconstructions combined with an energy and mass balance model yield a paleo-ELA of 4117±31 m asl (786 m lower than present) with temperature depressions of 3.8 to ~4.6°C compared to the present. This is less than the LGM reconstruction of temperature depression inferred from other climatic proxy records on the Tibetan Plateau and suggests that the LLGM glacial advance was a product of lower temperatures and slightly reduced precipitation compared to present, whereas the LGM was a more restricted advance in which much colder conditions were combined with much lower precipitation.

scholarly journals New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica

2019 ◽  
Vol 13 (11) ◽  
pp. 2935-2951 ◽  
Author(s):  
Keir A. Nichols ◽  
Brent M. Goehring ◽  
Greg Balco ◽  
Joanne S. Johnson ◽  
Andrew S. Hein ◽  
...  
Keyword(s):  
Sea Level ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Weddell Sea ◽  
Ice Thickness ◽  
Last Glacial ◽  
Cosmogenic Nuclide ◽  
Ice Stream ◽  
Exposure Ages

Abstract. We describe new Last Glacial Maximum (LGM) ice thickness constraints for three locations spanning the Weddell Sea Embayment (WSE) of Antarctica. Samples collected from the Shackleton Range, Pensacola Mountains, and the Lassiter Coast constrain the LGM thickness of the Slessor Glacier, Foundation Ice Stream, and grounded ice proximal to the modern Ronne Ice Shelf edge on the Antarctic Peninsula, respectively. Previous attempts to reconstruct LGM-to-present ice thickness changes around the WSE used measurements of long-lived cosmogenic nuclides, primarily 10Be. An absence of post-LGM apparent exposure ages at many sites led to LGM thickness reconstructions that were spatially highly variable and inconsistent with flow line modelling. Estimates for the contribution of the ice sheet occupying the WSE at the LGM to global sea level since deglaciation vary by an order of magnitude, from 1.4 to 14.1 m of sea level equivalent. Here we use a short-lived cosmogenic nuclide, in situ-produced 14C, which is less susceptible to inheritance problems than 10Be and other long-lived nuclides. We use in situ 14C to evaluate the possibility that sites with no post-LGM exposure ages are biased by cosmogenic nuclide inheritance due to surface preservation by cold-based ice and non-deposition of LGM-aged drift. Our measurements show that the Slessor Glacier was between 310 and up to 655 m thicker than present at the LGM. The Foundation Ice Stream was at least 800 m thicker, and ice on the Lassiter Coast was at least 385 m thicker than present at the LGM. With evidence for LGM thickening at all of our study sites, our in situ 14C measurements indicate that the long-lived nuclide measurements of previous studies were influenced by cosmogenic nuclide inheritance. Our inferred LGM configuration, which is primarily based on minimum ice thickness constraints and thus does not constrain an upper limit, indicates a relatively modest contribution to sea level rise since the LGM of < 4.6 m, and possibly as little as < 1.5 m.

scholarly journals Cosmogenic nuclide ages for Last Glacial Maximum moraine at Schnells Ridge, Southwest Tasmania

2004 ◽  
Vol 61 (3) ◽  
pp. 335-338 ◽  
Author(s):  
Kevin Kiernan ◽  
L. Keith Fifield ◽  
John Chappell
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Cosmogenic Nuclide ◽  
Southeast Australia ◽  
Exposure Ages

Moraines on Schnells Ridge, southwest Tasmania, have been dated using in situ 10Be. An age of 19,400 ± 600 yr is indicated for the well-preserved innermost moraine from consistent measurements on four large quartzite boulders. This corresponds closely with exposure ages reported by T.T. Barrows et al. (2002, Quaternary Science Reviews 21, 159–173) for Last Glacial Maximum glacial features farther north in Tasmania and southeast Australia. In contrast, ages between 39,000 and 141,000 yr were obtained from a series of boulders on a more extensive outer moraine, indicating that this has had a more complex history.

scholarly journals New Last Glacial Maximum Ice Thickness constraints for the Weddell Sea sector, Antarctica

2019 ◽  
Author(s):  
Keir A. Nichols ◽  
Brent M. Goehring ◽  
Greg Balco ◽  
Joanne S. Johnson ◽  
Andrew A. Hein ◽  
...  
Keyword(s):  
Sea Level ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Weddell Sea ◽  
Ice Thickness ◽  
Last Glacial ◽  
Cosmogenic Nuclide ◽  
Global Sea Level ◽  
Exposure Ages

Abstract. This paper describes new Last Glacial Maximum (LGM) ice thickness constraints for three locations spanning the Weddell Sea Embayment (WSE) of Antarctica. Samples collected from the Shackleton Range, Pensacola Mountains, and the Lassiter Coast constrain the LGM thickness of the Slessor Glacier, Foundation Ice Stream, and grounded ice proximal to the modern Ronne Ice Shelf Edge on the Antarctic Peninsula, respectively. Previous attempts to reconstruct LGM-to-present ice thickness changes around the WSE used measurements of long-lived cosmogenic nuclides, primarily 10Be. An absence of post-LGM apparent exposure ages at many sites led to LGM thickness reconstructions that were spatially highly variable, and inconsistent with flowline modeling. Estimates for the contribution of the ice sheet occupying the WSE at the LGM to global sea level since deglaciation vary by an order of magnitude, from 1.4 to 14.1 m of sea level equivalent. Here we use a cosmogenic nuclide, in situ produced 14C, to evaluate the possibility that sites with no post-LGM exposure ages are biased by cosmogenic nuclide inheritance due to surface preservation by cold-based ice and nondeposition of LGM-aged drift. Our measurements show that the Slessor Glacier was between 310 and 650 m thicker than present at the LGM. The Foundation Ice Stream was at least 800 m thicker, and ice on the Lassiter Coast was at least 385 m thicker than present at the LGM. With evidence for LGM thickening at all of our study sites, our in situ 14C measurements indicate that the long-lived nuclide measurements of previous studies were influenced by cosmogenic nuclide inheritance. Our LGM thickness constraints point toward a modest contribution from the Weddell Sea Embayment to global sea-level since deglaciation, with an estimated range of 2.2 to 5.8 m.

Seasonal variation of westerly jet over Asia in Last Glacial Maximum: Role of the Tibetan Plateau heating

2021 ◽  
pp. 1
Author(s):  
Jing Lei ◽  
Zhengguo Shi ◽  
Xiaoning Xie ◽  
Yingying Sha ◽  
Xinzhou Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Central Asia ◽  
Last Glacial Maximum ◽  
General Circulation ◽  
Heat Budget ◽  
Glacial Maximum ◽  
The Tibetan Plateau ◽  
Last Glacial ◽  
Westerly Jet

AbstractThe westerly jet (WJ) is an important component of atmospheric circulation, which is characterized by prominent seasonal variations in intensity and position. However, the response of WJ over Asia during the Last Glacial Maximum (LGM) is still not clear. Using general circulation model experiments, the seasonal behaviors of WJ over Central Asia and Japan are analyzed in this paper. The results show that, compared to present day (PD), the WJ presents a complicated response during the LGM, both in intensity and position. Over Central Asia, it becomes weaker in both summer and winter. But over Japan, it is enhanced in summer but becomes diminished in winter. In terms of position, the WJ over Central Asia shifts southwards in both summer and winter, while the WJ over Japan moves southwards in summer but does not change obviously relative to PD in winter. Such WJ changes are well explained by meridional temperature gradients in high troposphere, which is closely linked to seasonal thermal anomalies over the Tibetan Plateau (TP). Despite of cooler LGM condition, the anomalous warming center over TP becomes stronger in summer. Derived from the heat budget equation, the stronger heating center is mainly caused by the weaker adiabatic cooling generated from ascending motion over south of TP. In winter, the cooling over TP is also strengthened and mostly owes to the subsidence-induced weaker adiabatic heating. Due to the importance of WJ, the potential role of TP thermal effect should be focused when explaining the East Asian climate change during the LGM.

scholarly journals Tree endurance on the Tibetan Plateau marks the world’s highest known tree line of the Last Glacial Maximum

2009 ◽  
Vol 185 (1) ◽  
pp. 332-342 ◽  
Author(s):  
Lars Opgenoorth ◽  
Giovanni G. Vendramin ◽  
Kangshan Mao ◽  
Georg Miehe ◽  
Sabine Miehe ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
The Tibetan Plateau ◽  
Tree Line ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

scholarly journals The History and Driving Force for Prehistoric Human Expansion Upward to the Hinterland of the Tibetan Plateau Post–Last Glacial Maximum

2021 ◽  
Vol 13 (13) ◽  
pp. 7065
Author(s):  
Guangliang Hou ◽  
Weimiao Dong ◽  
Linhai Cai ◽  
Qingbo Wang ◽  
Menghan Qiu
Keyword(s):  
Tibetan Plateau ◽  
Last Glacial Maximum ◽  
Temporal Distribution ◽  
Glacial Maximum ◽  
Middle Pleistocene ◽  
The Tibetan Plateau ◽  
Human Occupation ◽  
Hunter Gatherers ◽  
Last Glacial ◽  
Spatio Temporal

The timing and motivation of prehistoric human expansion into the hinterland of the Tibetan Plateau (TP) is a widely debated scientific issue. Recent archaeological studies have brought forward predictions of the earliest human occupation of the TP to the late–Middle Pleistocene. However, massive human occupation of the TP did not appear until the termination of the Last Glacial Maximum (LGM). The spatio-temporal distribution of prehistoric hunter-gatherers on the TP varies significantly before the permanent occupation after 3600 BP (before present). Here, we report on environmental-archaeological evidence from the Canxionggashuo (CXGS) site in Yushu Prefecture, which provides information that is key to understanding the dynamics of post-LGM human occupation on the TP. Radiocarbon dating has revealed two occupation periods of the CXGS site at 8600–7100 cal (calibrated years) BP and 2400–2100 cal BP. The charcoal concentration in cultural layers correlates well with paleo–human activities. Hunter-gatherers expanded westwards from the northeastern margin of the TP to the hinterland of the TP during the warming period of the early–middle Holocene (~11,500–6000 BP). However, these groups retreated during the middle–late Holocene (~6000–3600 BP) under a cooling-drying climate. Prehistoric humans finally occupied the hinterland of the TP permanently after 3600 BP, with an enhanced cold-adaptive lifestyle, although the climate was still deteriorating.

Cosmogenic radionuclide evidence for the limited extent of last glacial maximum glaciers in the Tanggula Shan of the Central Tibetan Plateau

2006 ◽  
Vol 65 (02) ◽  
pp. 336-339 ◽  
Author(s):  
Patrick M. Colgan ◽  
Jeffrey S. Munroe ◽  
Zhou Shangzhe
Keyword(s):  
Tibetan Plateau ◽  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Limited Extent ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Central Tibetan Plateau ◽  
Exposure Ages ◽  
Cosmogenic Radionuclide

AbstractCosmogenic radionuclide (CRN) exposure ages provide evidence for the limited extent of last glacial maximum glaciers in the Tanggula Shan, central Tibetan Plateau. The most extensive advances occurred during or before marine oxygen isotope stage 6 (MIS-6) based on previous CRN exposure ages. The second most extensive advance occurred during or before MIS-4 based on previous ages and new ages of 41,400 ± 4300, and 66,800 ± 7100 10Be yr. A MIS-2 advance of less than 3 km occurred between 31,900 ± 3400 and 16,000 ± 1700 10Be yr.

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