Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging

Volcanic flanks subject to hydrothermal alteration become mechanically weak and gravitationally unstable, which may collapse and develop far-reaching landslides. The dynamics and trajectories of volcanic landslides are hardly preserved and challenging to determine, which is due to the steep slopes a...

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Published in:Frontiers in Earth Science
Main Authors: Marzban, P., Bredemeyer, S., Walter, T., Kästner, F., Müller, D., Chabrillat, S.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2023
Subjects:
Online Access:https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721_1/component/file_5019735/5019721.pdf
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spelling ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5019721 2023-07-16T03:59:08+02:00 Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging Marzban, P. Bredemeyer, S. Walter, T. Kästner, F. Müller, D. Chabrillat, S. 2023 application/pdf https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721_1/component/file_5019735/5019721.pdf unknown info:eu-repo/semantics/altIdentifier/doi/10.3389/feart.2023.1083043 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721_1/component/file_5019735/5019721.pdf info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/ Frontiers in Earth Science info:eu-repo/semantics/article 2023 ftgfzpotsdam https://doi.org/10.3389/feart.2023.1083043 2023-06-25T23:39:55Z Volcanic flanks subject to hydrothermal alteration become mechanically weak and gravitationally unstable, which may collapse and develop far-reaching landslides. The dynamics and trajectories of volcanic landslides are hardly preserved and challenging to determine, which is due to the steep slopes and the inherent instability. Here we analyze the proximal deposits of the 21 July 2014, landslide at Askja (Iceland), by combining high-resolution imagery from satellites and Unoccupied Aircraft Systems. We performed a Principal Component Analysis in combination with supervised classification to identify different material classes and altered rocks. We trained a maximum-likelihood classifier and were able to distinguish 7 different material classes and compare these to ground-based hyperspectral measurements that we conducted on different rock types found in the field. Results underline that the Northern part of the landslide source region is a hydrothermally altered material class, which bifurcates halfway downslope and then extends to the lake. We find that a large portion of this material is originating from a lava body at the landslide headwall, which is the persistent site of intense hydrothermal activity. By comparing the classification result to in-situ hyperspectral measurements, we were able to further identify the involved types of rocks and the degree of hydrothermal alteration. We further discuss associated effects of mechanical weakening and the relevance of the heterogeneous materials for the dynamics and processes of the landslide. As the study demonstrates the success of our approach for identification of altered and less altered materials, important implications for hazard assessment in the Askja caldera and elsewhere can be drawn. Article in Journal/Newspaper Iceland GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Askja ENVELOPE(-16.802,-16.802,65.042,65.042) Frontiers in Earth Science 11
institution Open Polar
collection GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
op_collection_id ftgfzpotsdam
language unknown
description Volcanic flanks subject to hydrothermal alteration become mechanically weak and gravitationally unstable, which may collapse and develop far-reaching landslides. The dynamics and trajectories of volcanic landslides are hardly preserved and challenging to determine, which is due to the steep slopes and the inherent instability. Here we analyze the proximal deposits of the 21 July 2014, landslide at Askja (Iceland), by combining high-resolution imagery from satellites and Unoccupied Aircraft Systems. We performed a Principal Component Analysis in combination with supervised classification to identify different material classes and altered rocks. We trained a maximum-likelihood classifier and were able to distinguish 7 different material classes and compare these to ground-based hyperspectral measurements that we conducted on different rock types found in the field. Results underline that the Northern part of the landslide source region is a hydrothermally altered material class, which bifurcates halfway downslope and then extends to the lake. We find that a large portion of this material is originating from a lava body at the landslide headwall, which is the persistent site of intense hydrothermal activity. By comparing the classification result to in-situ hyperspectral measurements, we were able to further identify the involved types of rocks and the degree of hydrothermal alteration. We further discuss associated effects of mechanical weakening and the relevance of the heterogeneous materials for the dynamics and processes of the landslide. As the study demonstrates the success of our approach for identification of altered and less altered materials, important implications for hazard assessment in the Askja caldera and elsewhere can be drawn.
format Article in Journal/Newspaper
author Marzban, P.
Bredemeyer, S.
Walter, T.
Kästner, F.
Müller, D.
Chabrillat, S.
spellingShingle Marzban, P.
Bredemeyer, S.
Walter, T.
Kästner, F.
Müller, D.
Chabrillat, S.
Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging
author_facet Marzban, P.
Bredemeyer, S.
Walter, T.
Kästner, F.
Müller, D.
Chabrillat, S.
author_sort Marzban, P.
title Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging
title_short Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging
title_full Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging
title_fullStr Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging
title_full_unstemmed Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging
title_sort hydrothermally altered deposits of 2014 askja landslide, iceland, identified by remote sensing imaging
publishDate 2023
url https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721_1/component/file_5019735/5019721.pdf
long_lat ENVELOPE(-16.802,-16.802,65.042,65.042)
geographic Askja
geographic_facet Askja
genre Iceland
genre_facet Iceland
op_source Frontiers in Earth Science
op_relation info:eu-repo/semantics/altIdentifier/doi/10.3389/feart.2023.1083043
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019721_1/component/file_5019735/5019721.pdf
op_rights info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by/4.0/
op_doi https://doi.org/10.3389/feart.2023.1083043
container_title Frontiers in Earth Science
container_volume 11
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