Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath
Landslide hazard motivates the need for a deeper understanding of the events that occur before, during, and after catastrophic slope failures. Due to the destructive nature of such events, in situ observation is often difficult or impossible. Here, we use data from a network of 58 seismic stations t...
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ftdoajarticles:oai:doaj.org/article:41cee2ebc24e4c0ca6efc00c2e2a3137 2023-05-15T16:49:04+02:00 Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath A. Schöpa W.-A. Chao B. P. Lipovsky N. Hovius R. S. White R. G. Green J. M. Turowski 2018-06-01T00:00:00Z https://doi.org/10.5194/esurf-6-467-2018 https://doaj.org/article/41cee2ebc24e4c0ca6efc00c2e2a3137 EN eng Copernicus Publications https://www.earth-surf-dynam.net/6/467/2018/esurf-6-467-2018.pdf https://doaj.org/toc/2196-6311 https://doaj.org/toc/2196-632X doi:10.5194/esurf-6-467-2018 2196-6311 2196-632X https://doaj.org/article/41cee2ebc24e4c0ca6efc00c2e2a3137 Earth Surface Dynamics, Vol 6, Pp 467-485 (2018) Dynamic and structural geology QE500-639.5 article 2018 ftdoajarticles https://doi.org/10.5194/esurf-6-467-2018 2022-12-31T11:09:40Z Landslide hazard motivates the need for a deeper understanding of the events that occur before, during, and after catastrophic slope failures. Due to the destructive nature of such events, in situ observation is often difficult or impossible. Here, we use data from a network of 58 seismic stations to characterise a large landslide at the Askja caldera, Iceland, on 21 July 2014. High data quality and extensive network coverage allow us to analyse both long- and short-period signals associated with the landslide, and thereby obtain information about its triggering, initiation, timing, and propagation. At long periods, a landslide force history inversion shows that the Askja landslide was a single, large event starting at the SE corner of the caldera lake at 23:24:05 UTC and propagating to the NW in the following 2 min. The bulk sliding mass was 7–16 × 10 10 kg, equivalent to a collapsed volume of 35–80 × 10 6 m 3 . The sliding mass was displaced downslope by 1260 ± 250 m. At short periods, a seismic tremor was observed for 30 min before the landslide. The tremor is approximately harmonic with a fundamental frequency of 2.3 Hz and shows time-dependent changes of its frequency content. We attribute the seismic tremor to stick-slip motion along the landslide failure plane. Accelerating motion leading up to the catastrophic slope failure culminated in an aseismic quiescent period for 2 min before the landslide. We propose that precursory seismic signals may be useful in landslide early-warning systems. The 8 h after the main landslide failure are characterised by smaller slope failures originating from the destabilised caldera wall decaying in frequency and magnitude. We introduce the term <q>afterslides</q> for this subsequent, declining slope activity after a large landslide. Article in Journal/Newspaper Iceland Directory of Open Access Journals: DOAJ Articles Askja ENVELOPE(-16.802,-16.802,65.042,65.042) Earth Surface Dynamics 6 2 467 485 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Dynamic and structural geology QE500-639.5 |
spellingShingle |
Dynamic and structural geology QE500-639.5 A. Schöpa W.-A. Chao B. P. Lipovsky N. Hovius R. S. White R. G. Green J. M. Turowski Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath |
topic_facet |
Dynamic and structural geology QE500-639.5 |
description |
Landslide hazard motivates the need for a deeper understanding of the events that occur before, during, and after catastrophic slope failures. Due to the destructive nature of such events, in situ observation is often difficult or impossible. Here, we use data from a network of 58 seismic stations to characterise a large landslide at the Askja caldera, Iceland, on 21 July 2014. High data quality and extensive network coverage allow us to analyse both long- and short-period signals associated with the landslide, and thereby obtain information about its triggering, initiation, timing, and propagation. At long periods, a landslide force history inversion shows that the Askja landslide was a single, large event starting at the SE corner of the caldera lake at 23:24:05 UTC and propagating to the NW in the following 2 min. The bulk sliding mass was 7–16 × 10 10 kg, equivalent to a collapsed volume of 35–80 × 10 6 m 3 . The sliding mass was displaced downslope by 1260 ± 250 m. At short periods, a seismic tremor was observed for 30 min before the landslide. The tremor is approximately harmonic with a fundamental frequency of 2.3 Hz and shows time-dependent changes of its frequency content. We attribute the seismic tremor to stick-slip motion along the landslide failure plane. Accelerating motion leading up to the catastrophic slope failure culminated in an aseismic quiescent period for 2 min before the landslide. We propose that precursory seismic signals may be useful in landslide early-warning systems. The 8 h after the main landslide failure are characterised by smaller slope failures originating from the destabilised caldera wall decaying in frequency and magnitude. We introduce the term <q>afterslides</q> for this subsequent, declining slope activity after a large landslide. |
format |
Article in Journal/Newspaper |
author |
A. Schöpa W.-A. Chao B. P. Lipovsky N. Hovius R. S. White R. G. Green J. M. Turowski |
author_facet |
A. Schöpa W.-A. Chao B. P. Lipovsky N. Hovius R. S. White R. G. Green J. M. Turowski |
author_sort |
A. Schöpa |
title |
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath |
title_short |
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath |
title_full |
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath |
title_fullStr |
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath |
title_full_unstemmed |
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath |
title_sort |
dynamics of the askja caldera july 2014 landslide, iceland, from seismic signal analysis: precursor, motion and aftermath |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/esurf-6-467-2018 https://doaj.org/article/41cee2ebc24e4c0ca6efc00c2e2a3137 |
long_lat |
ENVELOPE(-16.802,-16.802,65.042,65.042) |
geographic |
Askja |
geographic_facet |
Askja |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Earth Surface Dynamics, Vol 6, Pp 467-485 (2018) |
op_relation |
https://www.earth-surf-dynam.net/6/467/2018/esurf-6-467-2018.pdf https://doaj.org/toc/2196-6311 https://doaj.org/toc/2196-632X doi:10.5194/esurf-6-467-2018 2196-6311 2196-632X https://doaj.org/article/41cee2ebc24e4c0ca6efc00c2e2a3137 |
op_doi |
https://doi.org/10.5194/esurf-6-467-2018 |
container_title |
Earth Surface Dynamics |
container_volume |
6 |
container_issue |
2 |
container_start_page |
467 |
op_container_end_page |
485 |
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1766039142748127232 |