Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts
Abstract Using ground‐penetrating radar (GPR), we studied an entire 2.2 km long rock glacier (3780–4350 m asl) in the dry Andes of Chile with the aim of inferring its composition. In the high‐quality, unmigrated data, we identified the active layer base and the rock glacier floor. In between, hyperb...
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crwiley:10.1002/ppp.1846 2024-06-02T08:10:10+00:00 Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts Monnier, Sébastien Kinnard, Christophe Fondo Nacional de Desarrollo Científico y Tecnológico Dirección General de Agua (Chile) 2015 http://dx.doi.org/10.1002/ppp.1846 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.1846 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.1846 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Permafrost and Periglacial Processes volume 26, issue 4, page 335-346 ISSN 1045-6740 1099-1530 journal-article 2015 crwiley https://doi.org/10.1002/ppp.1846 2024-05-03T11:44:14Z Abstract Using ground‐penetrating radar (GPR), we studied an entire 2.2 km long rock glacier (3780–4350 m asl) in the dry Andes of Chile with the aim of inferring its composition. In the high‐quality, unmigrated data, we identified the active layer base and the rock glacier floor. In between, hyperbolae generated by diffracting boulders were inventoried; the ones along the rock glacier floor (n = 51) allowed determination of the average electromagnetic (EM) velocity in the rock glacier, the latter being further used for migration. Within the rock glacier (16–39 m thick), the EM velocity varies between 0.076 and 0.167 m.ns ‐1 the main stratigraphic features observed are upward‐dipping reflectors. The low EM velocities (<0.10 m.ns ‐1 ) found at some locations suggest the presence of significant unfrozen water fractions. A strong (R 2 = 0.77), inverse linear relationship was also found between the diffracting point density and the EM velocity, and was used to indicate the ice content in the rock glacier. The fraction of ice in the rock glacier was estimated to vary between 0.22 and 0.83, with an average of 0.66; these results were tested by recalculation of the EM velocity. The relationships between rock glacier development and glacial processes are questioned. Copyright © 2015 John Wiley & Sons, Ltd. Article in Journal/Newspaper Long Rock Permafrost and Periglacial Processes Wiley Online Library Long Rock ENVELOPE(-61.198,-61.198,-62.689,-62.689) Permafrost and Periglacial Processes 26 4 335 346 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Using ground‐penetrating radar (GPR), we studied an entire 2.2 km long rock glacier (3780–4350 m asl) in the dry Andes of Chile with the aim of inferring its composition. In the high‐quality, unmigrated data, we identified the active layer base and the rock glacier floor. In between, hyperbolae generated by diffracting boulders were inventoried; the ones along the rock glacier floor (n = 51) allowed determination of the average electromagnetic (EM) velocity in the rock glacier, the latter being further used for migration. Within the rock glacier (16–39 m thick), the EM velocity varies between 0.076 and 0.167 m.ns ‐1 the main stratigraphic features observed are upward‐dipping reflectors. The low EM velocities (<0.10 m.ns ‐1 ) found at some locations suggest the presence of significant unfrozen water fractions. A strong (R 2 = 0.77), inverse linear relationship was also found between the diffracting point density and the EM velocity, and was used to indicate the ice content in the rock glacier. The fraction of ice in the rock glacier was estimated to vary between 0.22 and 0.83, with an average of 0.66; these results were tested by recalculation of the EM velocity. The relationships between rock glacier development and glacial processes are questioned. Copyright © 2015 John Wiley & Sons, Ltd. |
author2 |
Fondo Nacional de Desarrollo Científico y Tecnológico Dirección General de Agua (Chile) |
format |
Article in Journal/Newspaper |
author |
Monnier, Sébastien Kinnard, Christophe |
spellingShingle |
Monnier, Sébastien Kinnard, Christophe Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts |
author_facet |
Monnier, Sébastien Kinnard, Christophe |
author_sort |
Monnier, Sébastien |
title |
Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts |
title_short |
Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts |
title_full |
Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts |
title_fullStr |
Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts |
title_full_unstemmed |
Internal Structure and Composition of a Rock Glacier in the Dry Andes, Inferred from Ground‐penetrating Radar Data and its Artefacts |
title_sort |
internal structure and composition of a rock glacier in the dry andes, inferred from ground‐penetrating radar data and its artefacts |
publisher |
Wiley |
publishDate |
2015 |
url |
http://dx.doi.org/10.1002/ppp.1846 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.1846 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.1846 |
long_lat |
ENVELOPE(-61.198,-61.198,-62.689,-62.689) |
geographic |
Long Rock |
geographic_facet |
Long Rock |
genre |
Long Rock Permafrost and Periglacial Processes |
genre_facet |
Long Rock Permafrost and Periglacial Processes |
op_source |
Permafrost and Periglacial Processes volume 26, issue 4, page 335-346 ISSN 1045-6740 1099-1530 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/ppp.1846 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
26 |
container_issue |
4 |
container_start_page |
335 |
op_container_end_page |
346 |
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1800755983139471360 |