Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America
Abstract The Sierra los Cuchumatanes (3837 m), Guatemala, supported a plateau ice cap and valley glaciers around Montaña San Juan (3784 m) that totaled ∼ 43 km 2 in area during the last local glacial maximum. Former ice limits are defined by sharp-crested lateral and terminal moraines that extend to...
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crcambridgeupr:10.1016/j.yqres.2010.04.010 2024-09-15T18:11:44+00:00 Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America Roy, Alex J. Lachniet, Matthew S. 2010 http://dx.doi.org/10.1016/j.yqres.2010.04.010 http://api.elsevier.com/content/article/PII:S0033589410000475?httpAccept=text/xml http://api.elsevier.com/content/article/PII:S0033589410000475?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400009844 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 74, issue 1, page 1-7 ISSN 0033-5894 1096-0287 journal-article 2010 crcambridgeupr https://doi.org/10.1016/j.yqres.2010.04.010 2024-08-28T04:03:46Z Abstract The Sierra los Cuchumatanes (3837 m), Guatemala, supported a plateau ice cap and valley glaciers around Montaña San Juan (3784 m) that totaled ∼ 43 km 2 in area during the last local glacial maximum. Former ice limits are defined by sharp-crested lateral and terminal moraines that extend to elevations of ∼ 3450 m along the ice cap margin, and to ca. 3000–3300 m for the valley glaciers. Equilibrium-line altitudes (ELAs) estimated using the area–altitude balance ratio method for the maximum late Quaternary glaciation reached as low as 3470 m for the valley glaciers and 3670 m for the Mayan Ice Cap. Relative to the modern altitude of the 0°C isotherm of ∼ 4840 m, we determined ELA depressions of 1110–1436 m. If interpreted in terms of a depression of the freezing level during maximal glaciation along the modern lapse rate of − 5.3°C km –1 , this ΔELA indicates tropical highland cooling of ∼ 5.9 to 7.6 ± 1.2°C. Our data support greater glacial highland cooling than at sea level, implying a high tropical sensitivity to global climate changes. The large magnitude of ELA depression in Guatemala may have been partially forced by enhanced wetness associated with southward excursions of the boreal winter polar air mass. Article in Journal/Newspaper Ice cap Cambridge University Press Quaternary Research 74 1 1 7 |
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Cambridge University Press |
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language |
English |
description |
Abstract The Sierra los Cuchumatanes (3837 m), Guatemala, supported a plateau ice cap and valley glaciers around Montaña San Juan (3784 m) that totaled ∼ 43 km 2 in area during the last local glacial maximum. Former ice limits are defined by sharp-crested lateral and terminal moraines that extend to elevations of ∼ 3450 m along the ice cap margin, and to ca. 3000–3300 m for the valley glaciers. Equilibrium-line altitudes (ELAs) estimated using the area–altitude balance ratio method for the maximum late Quaternary glaciation reached as low as 3470 m for the valley glaciers and 3670 m for the Mayan Ice Cap. Relative to the modern altitude of the 0°C isotherm of ∼ 4840 m, we determined ELA depressions of 1110–1436 m. If interpreted in terms of a depression of the freezing level during maximal glaciation along the modern lapse rate of − 5.3°C km –1 , this ΔELA indicates tropical highland cooling of ∼ 5.9 to 7.6 ± 1.2°C. Our data support greater glacial highland cooling than at sea level, implying a high tropical sensitivity to global climate changes. The large magnitude of ELA depression in Guatemala may have been partially forced by enhanced wetness associated with southward excursions of the boreal winter polar air mass. |
format |
Article in Journal/Newspaper |
author |
Roy, Alex J. Lachniet, Matthew S. |
spellingShingle |
Roy, Alex J. Lachniet, Matthew S. Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America |
author_facet |
Roy, Alex J. Lachniet, Matthew S. |
author_sort |
Roy, Alex J. |
title |
Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America |
title_short |
Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America |
title_full |
Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America |
title_fullStr |
Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America |
title_full_unstemmed |
Late Quaternary glaciation and equilibrium-line altitudes of the Mayan Ice Cap, Guatemala, Central America |
title_sort |
late quaternary glaciation and equilibrium-line altitudes of the mayan ice cap, guatemala, central america |
publisher |
Cambridge University Press (CUP) |
publishDate |
2010 |
url |
http://dx.doi.org/10.1016/j.yqres.2010.04.010 http://api.elsevier.com/content/article/PII:S0033589410000475?httpAccept=text/xml http://api.elsevier.com/content/article/PII:S0033589410000475?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400009844 |
genre |
Ice cap |
genre_facet |
Ice cap |
op_source |
Quaternary Research volume 74, issue 1, page 1-7 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1016/j.yqres.2010.04.010 |
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Quaternary Research |
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74 |
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1 |
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7 |
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1810449309362028544 |