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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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-03-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2023.1083043/full |
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| author | Pouria Marzban Pouria Marzban Stefan Bredemeyer Stefan Bredemeyer Thomas R. Walter Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat Sabine Chabrillat |
| author_facet | Pouria Marzban Pouria Marzban Stefan Bredemeyer Stefan Bredemeyer Thomas R. Walter Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat Sabine Chabrillat |
| author_sort | Pouria Marzban |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-04-10T05:13:53Z |
| format | Article |
| id | doaj.art-89faf09af8e1418c9740a4fc710b5333 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-10T05:13:53Z |
| publishDate | 2023-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-89faf09af8e1418c9740a4fc710b53332023-03-09T04:35:43ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-03-011110.3389/feart.2023.10830431083043Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imagingPouria Marzban0Pouria Marzban1Stefan Bredemeyer2Stefan Bredemeyer3Thomas R. Walter4Thomas R. Walter5Friederike Kästner6Daniel Müller7Sabine Chabrillat8Sabine Chabrillat9GFZ German Research Centre for Geosciences, Physics of Earthquakes and Volcanoes, Telegrafenberg, Potsdam, GermanyGerman Archaeological Institute (DAI), Scientific Computing Unit, Central Research Services, Berlin, GermanyGFZ German Research Centre for Geosciences, Physics of Earthquakes and Volcanoes, Telegrafenberg, Potsdam, GermanyGEOMAR Helmholtz Center for Ocean Research Kiel, Research Division 4, Magmatic and Hydrothermal Systems, Kiel, GermanyGFZ German Research Centre for Geosciences, Physics of Earthquakes and Volcanoes, Telegrafenberg, Potsdam, GermanyInstitute of Geosciences, University of Potsdam, Potsdam, GermanyGFZ German Research Center for Geosciences, Remote Sensing and Geoinformatics, Telegrafenberg, Potsdam, GermanyGFZ German Research Centre for Geosciences, Physics of Earthquakes and Volcanoes, Telegrafenberg, Potsdam, GermanyGFZ German Research Center for Geosciences, Remote Sensing and Geoinformatics, Telegrafenberg, Potsdam, GermanyInstitute of Soil Sciences, Leibniz University Hannover (LUH), Hannover, GermanyVolcanic 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.https://www.frontiersin.org/articles/10.3389/feart.2023.1083043/fullremote sensinghydrothermal alterationAskja landslidePCAclassificationvolcano hazards |
| spellingShingle | Pouria Marzban Pouria Marzban Stefan Bredemeyer Stefan Bredemeyer Thomas R. Walter Thomas R. Walter Friederike Kästner Daniel Müller Sabine Chabrillat Sabine Chabrillat Hydrothermally altered deposits of 2014 Askja landslide, Iceland, identified by remote sensing imaging Frontiers in Earth Science remote sensing hydrothermal alteration Askja landslide PCA classification volcano hazards |
| title | 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_short | 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 |
| topic | remote sensing hydrothermal alteration Askja landslide PCA classification volcano hazards |
| url | https://www.frontiersin.org/articles/10.3389/feart.2023.1083043/full |
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