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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ftdoajarticles:oai:doaj.org/article:89faf09af8e1418c9740a4fc710b5333 2023-05-15T16:48:43+02:00 Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging Pouria Marzban Stefan Bredemeyer Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat 2023-03-01T00:00:00Z https://doi.org/10.3389/feart.2023.1083043 https://doaj.org/article/89faf09af8e1418c9740a4fc710b5333 EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2023.1083043/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2023.1083043 https://doaj.org/article/89faf09af8e1418c9740a4fc710b5333 Frontiers in Earth Science, Vol 11 (2023) remote sensing hydrothermal alteration Askja landslide PCA classification volcano hazards Science Q article 2023 ftdoajarticles https://doi.org/10.3389/feart.2023.1083043 2023-03-12T01:32:34Z 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 Directory of Open Access Journals: DOAJ Articles Askja ENVELOPE(-16.802,-16.802,65.042,65.042) Frontiers in Earth Science 11 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
remote sensing hydrothermal alteration Askja landslide PCA classification volcano hazards Science Q |
spellingShingle |
remote sensing hydrothermal alteration Askja landslide PCA classification volcano hazards Science Q Pouria Marzban Stefan Bredemeyer Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging |
topic_facet |
remote sensing hydrothermal alteration Askja landslide PCA classification volcano hazards Science Q |
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 |
Pouria Marzban Stefan Bredemeyer Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat |
author_facet |
Pouria Marzban Stefan Bredemeyer Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat |
author_sort |
Pouria Marzban |
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 |
publisher |
Frontiers Media S.A. |
publishDate |
2023 |
url |
https://doi.org/10.3389/feart.2023.1083043 https://doaj.org/article/89faf09af8e1418c9740a4fc710b5333 |
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, Vol 11 (2023) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2023.1083043/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2023.1083043 https://doaj.org/article/89faf09af8e1418c9740a4fc710b5333 |
op_doi |
https://doi.org/10.3389/feart.2023.1083043 |
container_title |
Frontiers in Earth Science |
container_volume |
11 |
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1766038797618774016 |