Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field
Although its Holocene glacier history is still subject to debate, the ongoing iconic decline of Kilimanjaro's largest remaining ice body, the Northern Ice Field (NIF), has been documented extensively based on surface and photogrammetric measurements. The study presented here adds, for the first...
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ftdoajarticles:oai:doaj.org/article:fc1b2d082d374f11899bc1c0f3cf303f 2023-05-15T16:39:16+02:00 Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field P. Bohleber L. Sold D. R. Hardy M. Schwikowski P. Klenk A. Fischer P. Sirguey N. J. Cullen M. Potocki H. Hoffmann P. Mayewski 2017-02-01T00:00:00Z https://doi.org/10.5194/tc-11-469-2017 https://doaj.org/article/fc1b2d082d374f11899bc1c0f3cf303f EN eng Copernicus Publications http://www.the-cryosphere.net/11/469/2017/tc-11-469-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-469-2017 https://doaj.org/article/fc1b2d082d374f11899bc1c0f3cf303f The Cryosphere, Vol 11, Iss 1, Pp 469-482 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-469-2017 2022-12-31T02:17:55Z Although its Holocene glacier history is still subject to debate, the ongoing iconic decline of Kilimanjaro's largest remaining ice body, the Northern Ice Field (NIF), has been documented extensively based on surface and photogrammetric measurements. The study presented here adds, for the first time, ground-penetrating radar (GPR) data at centre frequencies of 100 and 200 MHz to investigate bed topography, ice thickness and internal stratigraphy at NIF. The direct comparison of the GPR signal to the visible glacier stratigraphy at NIF's vertical walls is used to validate ice thickness and reveals that the major internal reflections seen by GPR can be associated with dust layers. Internal reflections can be traced consistently within our 200 MHz profiles, indicating an uninterrupted, spatially coherent internal layering within NIF's central flat area. We show that, at least for the upper 30 m, it is possible to follow isochrone layers between two former NIF ice core drilling sites and a sampling site on NIF's vertical wall. As a result, these isochrone layers provide constraints for future attempts at linking age–depth information obtained from multiple locations at NIF. The GPR profiles reveal an ice thickness ranging between (6.1 ± 0.5) and (53.5 ± 1.0) m. Combining these data with a very high resolution digital elevation model we spatially extrapolate ice thickness and give an estimate of the total ice volume remaining at NIF's southern portion as (12.0 ± 0.3) × 10 6 m 3 . Article in Journal/Newspaper ice core The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 11 1 469 482 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 P. Bohleber L. Sold D. R. Hardy M. Schwikowski P. Klenk A. Fischer P. Sirguey N. J. Cullen M. Potocki H. Hoffmann P. Mayewski Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Although its Holocene glacier history is still subject to debate, the ongoing iconic decline of Kilimanjaro's largest remaining ice body, the Northern Ice Field (NIF), has been documented extensively based on surface and photogrammetric measurements. The study presented here adds, for the first time, ground-penetrating radar (GPR) data at centre frequencies of 100 and 200 MHz to investigate bed topography, ice thickness and internal stratigraphy at NIF. The direct comparison of the GPR signal to the visible glacier stratigraphy at NIF's vertical walls is used to validate ice thickness and reveals that the major internal reflections seen by GPR can be associated with dust layers. Internal reflections can be traced consistently within our 200 MHz profiles, indicating an uninterrupted, spatially coherent internal layering within NIF's central flat area. We show that, at least for the upper 30 m, it is possible to follow isochrone layers between two former NIF ice core drilling sites and a sampling site on NIF's vertical wall. As a result, these isochrone layers provide constraints for future attempts at linking age–depth information obtained from multiple locations at NIF. The GPR profiles reveal an ice thickness ranging between (6.1 ± 0.5) and (53.5 ± 1.0) m. Combining these data with a very high resolution digital elevation model we spatially extrapolate ice thickness and give an estimate of the total ice volume remaining at NIF's southern portion as (12.0 ± 0.3) × 10 6 m 3 . |
format |
Article in Journal/Newspaper |
author |
P. Bohleber L. Sold D. R. Hardy M. Schwikowski P. Klenk A. Fischer P. Sirguey N. J. Cullen M. Potocki H. Hoffmann P. Mayewski |
author_facet |
P. Bohleber L. Sold D. R. Hardy M. Schwikowski P. Klenk A. Fischer P. Sirguey N. J. Cullen M. Potocki H. Hoffmann P. Mayewski |
author_sort |
P. Bohleber |
title |
Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field |
title_short |
Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field |
title_full |
Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field |
title_fullStr |
Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field |
title_full_unstemmed |
Ground-penetrating radar reveals ice thickness and undisturbed englacial layers at Kilimanjaro's Northern Ice Field |
title_sort |
ground-penetrating radar reveals ice thickness and undisturbed englacial layers at kilimanjaro's northern ice field |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-469-2017 https://doaj.org/article/fc1b2d082d374f11899bc1c0f3cf303f |
genre |
ice core The Cryosphere |
genre_facet |
ice core The Cryosphere |
op_source |
The Cryosphere, Vol 11, Iss 1, Pp 469-482 (2017) |
op_relation |
http://www.the-cryosphere.net/11/469/2017/tc-11-469-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-469-2017 https://doaj.org/article/fc1b2d082d374f11899bc1c0f3cf303f |
op_doi |
https://doi.org/10.5194/tc-11-469-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
1 |
container_start_page |
469 |
op_container_end_page |
482 |
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1766029602145173504 |