Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru
Characterising glaciological change within the tropical Andes is important because tropical glaciers are sensitive to climate change. Our understanding of glacier dynamics and how tropical glaciers respond to global climate perturbations is poorly constrained. Studies of past glaciation in the tropi...
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Online Access: | http://dx.doi.org/10.3389/feart.2022.838826 https://www.frontiersin.org/articles/10.3389/feart.2022.838826/full |
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crfrontiers:10.3389/feart.2022.838826 2024-02-11T10:04:45+01:00 Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru Lee, Ethan Ross, Neil Henderson, Andrew C. G. Russell, Andrew J. Jamieson, Stewart S. R. Fabel, Derek Natural Environment Research Council Royal Society 2022 http://dx.doi.org/10.3389/feart.2022.838826 https://www.frontiersin.org/articles/10.3389/feart.2022.838826/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Earth Science volume 10 ISSN 2296-6463 General Earth and Planetary Sciences journal-article 2022 crfrontiers https://doi.org/10.3389/feart.2022.838826 2024-01-26T10:10:08Z Characterising glaciological change within the tropical Andes is important because tropical glaciers are sensitive to climate change. Our understanding of glacier dynamics and how tropical glaciers respond to global climate perturbations is poorly constrained. Studies of past glaciation in the tropical Andes have focused on locations where glaciers are still present or recently vacated cirques at high elevations. Few studies focused on lower elevation localities because it was assumed glaciers did not exist or were not as extensive. We present the first geomorphological evidence for past glaciations of the Lagunas de Las Huaringas, northern Peru, at elevations of 3,900–2,600 m a.s.l. Mapping was conducted using remotely-sensed optical imagery and a newly created high-resolution (∼2.5 m) digital elevation model (DEM). The area has abundant evidence for glaciation, including moraines, glacial cirques, hummocky terrain, glacial lineations and ice-sculpted bedrock. Two potential models for glaciation are hypothesised: 1) plateau-fed ice cap, or 2) valley glaciation. Assuming glaciers reached their maximum extent during the Local Last Glacial Maximum (LLGM), between 23.5 ± 0.5 and 21.2 ± 0.8 ka, the maximum reconstructed glacial area was 75.6 km 2 . A mean equilibrium line altitude (ELA) of 3,422 ± 30 m was calculated, indicating an ELA change of −1,178 ± 10 m compared to modern snowline elevation. There is an east to west ELA elevation gradient, lower in the east and higher in the west, in-line with modern day transfer of moisture. Applying lapse rates between 5.5 and 7.5°C/km provides a LLGM temperature cooling of between 6.5–8.8°C compared to present. These values are comparable to upper estimates from other studies within the northern tropical Andes and from ice-core reconstructions. The mapping of glacial geomorphology within the Lagunas de las Huaringas, evidences, for the first time, extensive glaciation in a low elevation region of northern Peru, with implications for our understanding of past climate in the ... Article in Journal/Newspaper Ice cap ice core Frontiers (Publisher) Ela ENVELOPE(9.642,9.642,63.170,63.170) Frontiers in Earth Science 10 |
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Open Polar |
collection |
Frontiers (Publisher) |
op_collection_id |
crfrontiers |
language |
unknown |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Lee, Ethan Ross, Neil Henderson, Andrew C. G. Russell, Andrew J. Jamieson, Stewart S. R. Fabel, Derek Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru |
topic_facet |
General Earth and Planetary Sciences |
description |
Characterising glaciological change within the tropical Andes is important because tropical glaciers are sensitive to climate change. Our understanding of glacier dynamics and how tropical glaciers respond to global climate perturbations is poorly constrained. Studies of past glaciation in the tropical Andes have focused on locations where glaciers are still present or recently vacated cirques at high elevations. Few studies focused on lower elevation localities because it was assumed glaciers did not exist or were not as extensive. We present the first geomorphological evidence for past glaciations of the Lagunas de Las Huaringas, northern Peru, at elevations of 3,900–2,600 m a.s.l. Mapping was conducted using remotely-sensed optical imagery and a newly created high-resolution (∼2.5 m) digital elevation model (DEM). The area has abundant evidence for glaciation, including moraines, glacial cirques, hummocky terrain, glacial lineations and ice-sculpted bedrock. Two potential models for glaciation are hypothesised: 1) plateau-fed ice cap, or 2) valley glaciation. Assuming glaciers reached their maximum extent during the Local Last Glacial Maximum (LLGM), between 23.5 ± 0.5 and 21.2 ± 0.8 ka, the maximum reconstructed glacial area was 75.6 km 2 . A mean equilibrium line altitude (ELA) of 3,422 ± 30 m was calculated, indicating an ELA change of −1,178 ± 10 m compared to modern snowline elevation. There is an east to west ELA elevation gradient, lower in the east and higher in the west, in-line with modern day transfer of moisture. Applying lapse rates between 5.5 and 7.5°C/km provides a LLGM temperature cooling of between 6.5–8.8°C compared to present. These values are comparable to upper estimates from other studies within the northern tropical Andes and from ice-core reconstructions. The mapping of glacial geomorphology within the Lagunas de las Huaringas, evidences, for the first time, extensive glaciation in a low elevation region of northern Peru, with implications for our understanding of past climate in the ... |
author2 |
Natural Environment Research Council Royal Society |
format |
Article in Journal/Newspaper |
author |
Lee, Ethan Ross, Neil Henderson, Andrew C. G. Russell, Andrew J. Jamieson, Stewart S. R. Fabel, Derek |
author_facet |
Lee, Ethan Ross, Neil Henderson, Andrew C. G. Russell, Andrew J. Jamieson, Stewart S. R. Fabel, Derek |
author_sort |
Lee, Ethan |
title |
Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru |
title_short |
Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru |
title_full |
Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru |
title_fullStr |
Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru |
title_full_unstemmed |
Palaeoglaciation in the Low Latitude, Low Elevation Tropical Andes, Northern Peru |
title_sort |
palaeoglaciation in the low latitude, low elevation tropical andes, northern peru |
publisher |
Frontiers Media SA |
publishDate |
2022 |
url |
http://dx.doi.org/10.3389/feart.2022.838826 https://www.frontiersin.org/articles/10.3389/feart.2022.838826/full |
long_lat |
ENVELOPE(9.642,9.642,63.170,63.170) |
geographic |
Ela |
geographic_facet |
Ela |
genre |
Ice cap ice core |
genre_facet |
Ice cap ice core |
op_source |
Frontiers in Earth Science volume 10 ISSN 2296-6463 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/feart.2022.838826 |
container_title |
Frontiers in Earth Science |
container_volume |
10 |
_version_ |
1790601475824549888 |