Reconstruction of equilibrium-line altitudes for tropical and sub-tropical glaciers

Benn, Douglas I.; Owen, Lewis A.; Osmaston, Henry; Seltzer, Geoffrey O.; Porter, Stephen C.; Mark, Bryan G.

doi:10.1016/j.quaint.2005.02.003

Cited by 209 publications

(178 citation statements)

References 53 publications

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“…Previous works highlighted that the AABR method creates better reconstructions than the other methods and is the only one that can be applied to current glaciers and paleoglaciers [75,81]. On the other hand, the paleoELA 2 (4993 m) reconstructed in this work can be a representative reconstruction of the maximum extension of all the paleoglaciers towards the Nevado Coropuna northeast (Figure 7), including the ice masses located in sites isolated topographically from the surrounding peaks.…”

Section: Paleoelamentioning

confidence: 76%

“…The mapping of paleoglaciers ( Figure 7), based on the geomorphological map, led to the ELA and paleoELA reconstruction by the AABR method [75], because where good topographic maps and air photograph coverage are available, this method is more rigorous than any other [81]. The application of the same method for current ELAs and paleoELAs is almost a novelty in the Tropical Andes because, with few exceptions [77,82], previous works in Coropuna [47] and other mountains [83] used different procedures for the present and the past.…”

Section: Ela and Paleoela Reconstructionmentioning

confidence: 99%

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Prospecting Glacial Ages and Paleoclimatic Reconstructions Northeastward of Nevado Coropuna (16° S, 73° W, 6377 m), Arid Tropical Andes

et al. 2018

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This work investigates the timing, paleoclimatic framework and inter-hemispheric teleconnections inferred from the glaciers last maximum extension and the deglaciation onset in the Arid Tropical Andes. A study area was selected to the northeastward of the Nevado Coropuna, the volcano currently covered by the largest tropical glacier on Earth. The current glacier extent, the moraines deposited in the past and paleoglaciers at their maximum extension have been mapped. The present and past Equilibrium Line Altitudes (ELA and paleoELA) have been reconstructed and the chlorine-36 ages have been calculated, for preliminary absolute dating of glacial and volcanic processes. The paleoELA depression, the thermometers installed in the study area and the accumulation data previously published allowed development of paleotemperature and paleoprecipitation models. The Coropuna glaciers were in maximum extension (or glacial standstill) 20-12 ka ago (and maybe earlier). This last maximum extension was contemporary to the Heinrich 2-1 and Younger Dryas events and the Tauca and Coipasa paleolake transgressions on Bolivian Altiplano. The maximum paleoELA depression (991 m) shows a colder (−6.4 • C) and moister climate with precipitation ×1.2-×2.8 higher than the present. The deglaciation onset in the Arid Tropical Andes was 15-11 ka ago, earlier in the most southern, arid, and low mountains and later in the northernmost, less arid, and higher mountains.

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Section: Paleoelamentioning

confidence: 76%

Section: Ela and Paleoela Reconstructionmentioning

confidence: 99%

Prospecting Glacial Ages and Paleoclimatic Reconstructions Northeastward of Nevado Coropuna (16° S, 73° W, 6377 m), Arid Tropical Andes

et al. 2018

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“…Recent work on sub-tropical glaciers has emphasised the importance of reliable absolute dating when using glacial-geological evidence for climate model comparisons (e.g. Benn et al, 2005;Mark et al, 2005;Smith et al, 2005). Such dating is especially important when comparing palaeoclimate results from regions in which the glaciers did not reach a maximum during the global LGM (e.g.…”

Section: Discussionmentioning

confidence: 99%

Reconstructing glacier-based climates of LGM Europe and Russia – Part 2: A dataset of LGM precipitation/temperature relations derived from degree-day modelling of palaeo glaciers

2008

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Abstract. The study of European and Russian Quaternary glacial-geological evidence during the last 15 years has generated sufficient data to use former glacial extent as a proxy for Last Glacial Maximum (LGM) climate (precipitation and temperature) at a continental scale. Utilisation of such data is relevant for two reasons. First, continental to global scale proxy reconstructions of past climate are an important tool in the assessment of retrospective general circulation model (GCM) simulations. Second, the development of a multiproxy approach will result in a more robust proxy based climate signal. A new and independent dataset of 36 LGM precipitation and temperature relationships derived from European and Russian mountain regions is presented in this paper. A simple glacier-climate model was used to establish the optimum LGM precipitation/temperature conditions for each region from a suite of over 4000 model climates using the principle of zero cumulative mass balance. Clear regional trends are present in the reconstructed LGM precipitation and temperature curves; assuming present precipitation temperature anomalies north of the Alps are 2 • C and 5 • C larger than those in the western and eastern Mediterranean, respectively. In Russia the model results suggest that the climates in both the Arctic Urals and Puterana Plateau were probably conducive to the existence of small mountain glaciers at the LGM.

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“…The reconstructed DELAs are used to estimate past temperature and/or precipitation changes and to assess regional climatic gradients and variability. Benn and Lehmkuhl (2000), Owen and Benn (2005) and Benn et al (2003) describe how reconstructing former ELAs and DELAs can be problematic in high mountain regions, specifically the Himalayan-Tibetan orogen. These problems occur because of extreme topographic Martinson et al, 1987, andShackleton et al, 1990).…”

Section: Elasmentioning

confidence: 99%

Quaternary glaciation of the Himalayan–Tibetan orogen

Owen

Caffee

Finkel

et al. 2008

J Quaternary Science

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211

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Glacial geological evidence from throughout the Himalayan-Tibetan orogen is examined to determine the timing and extent of late Quaternary glaciation in this region and its relation to similar changes on a global scale. The evidence summarised here supports the existence of expanded ice caps and extensive valley glacier systems throughout the region during the late Quaternary. However, it cannot yet be determined whether the timing of the extent of maximum glaciation was synchronous throughout the entire region or whether the response was more varied. The lack of organic material needed for radiocarbon dating has hindered past progress in glacial reconstruction; however, application of optically stimulated luminescence and terrestrial cosmogenic radionuclide methods has recently expanded the number of chronologies throughout the region. Limits to the precision and accuracy available with these methods and, more importantly, geological uncertainty imposed by processes of moraine formation and alteration both conspire to limit the time resolution on which correlations can be made to Milankovitch timescales (several ka). In order to put all studies on a common scale, well-dated sites have been re-evaluated and all the published terrestrial cosmogenic nuclide ages for moraine boulders and glacially eroded surfaces in the Himalayan-Tibetan orogen have been recalculated. Locally detailed studies indicate that there are considerable variations in the extent of glaciation from one region to the next during a glaciation. Glaciers throughout monsoon-influenced Tibet, the Himalaya and the Transhimalaya are likely synchronous both with climate change resulting from oscillations in the South Asian monsoon and with Northern Hemisphere cooling cycles. In contrast, glaciers in Pamir in the far western regions of the Himalayan-Tibet orogen advanced asynchronously relative to the other regions that are monsooninfluenced regions and appear to be mainly in phase with the Northern Hemisphere cooling cycles. Broad patterns of local and regional variability based on equilibrium-line altitudes have yet to be fully assessed, but have the potential to help define changes in climatic gradients over time.

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Reconstruction of equilibrium-line altitudes for tropical and sub-tropical glaciers

Cited by 209 publications

References 53 publications

Prospecting Glacial Ages and Paleoclimatic Reconstructions Northeastward of Nevado Coropuna (16° S, 73° W, 6377 m), Arid Tropical Andes

Prospecting Glacial Ages and Paleoclimatic Reconstructions Northeastward of Nevado Coropuna (16° S, 73° W, 6377 m), Arid Tropical Andes

Reconstructing glacier-based climates of LGM Europe and Russia – Part 2: A dataset of LGM precipitation/temperature relations derived from degree-day modelling of palaeo glaciers

Quaternary glaciation of the Himalayan–Tibetan orogen

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