Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland
Understanding dikes is vital as they serve both as bodies that build the crust and as conduits that feed eruptions, and must be monitored to evaluate volcanic hazard. During the 2014-15 Bárðarbunga rifting event, Iceland, intenseseismicity accompanied the intrusion of a ∼ 50 km lateral dike which cu...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/286414 2024-01-14T10:07:56+01:00 Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland Woods, J Winder, T White, RS Brandsdóttir, B 2019 application/pdf https://www.repository.cam.ac.uk/handle/1810/286414 https://doi.org/10.17863/CAM.33723 eng eng Elsevier BV http://dx.doi.org/10.1016/j.epsl.2018.10.032 Earth and Planetary Science Letters https://www.repository.cam.ac.uk/handle/1810/286414 doi:10.17863/CAM.33723 Bardarbunga dike intrusion microseismicity cross-correlation rifting induced earthquakes Article 2019 ftunivcam https://doi.org/10.17863/CAM.33723 2023-12-21T23:19:35Z Understanding dikes is vital as they serve both as bodies that build the crust and as conduits that feed eruptions, and must be monitored to evaluate volcanic hazard. During the 2014-15 Bárðarbunga rifting event, Iceland, intenseseismicity accompanied the intrusion of a ∼ 50 km lateral dike which culminated in a 6 month long eruption. We here present relocations of earthquakes induced by the lateral dike intrusion, using cross-correlated, sub-sample relative travel times. The ∼ 100 m spatial resolution achieved reveals the complexity of the dike propagation pathway and dynamics (jerky, segmented), and allows us to address the precise relationship between the dike and seismicity, with direct implications for hazard monitoring. The spatio-temporal characteristics of the induced seismicity can be directly linked in the first instance to propagation of the tip and opening of the dike, and following this - after dike opening - indicate a relationship with magma pressure changes (i.e. dike inflation/deflation), followed by a general ’post-opening’ decay. Seismicity occurs only at the base of the dike, where dike-imposed stresses - combined with the background tectonic stress (from regional extension over > 200 years since last rifting) - are sufficient to induce failure of pre-existing weaknesses in the crust, while the greatest opening is at shallower depths. Emplacement oblique to the spreading ridge resulted in left-lateral shear motion along the distal dike section (studied here), and a prevalence of left-lateral shear failure. Fault plane strikes are predominately independent of the orientation of lineations delineated by the hypocenters, indicating that they are controlled by the underlying host rock fabric. This high-resolution study provides unprecedented opportunity for comparison with both geodetic and field (frozen dike) observations, and development and consolidation of analytical and analogue models, with implications for rifting processes and real-time monitoring of magma intrusion. Seismometers ... Article in Journal/Newspaper Iceland Apollo - University of Cambridge Repository Bardarbunga ENVELOPE(-17.528,-17.528,64.635,64.635) Holuhraun ENVELOPE(-16.831,-16.831,64.852,64.852) |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Bardarbunga dike intrusion microseismicity cross-correlation rifting induced earthquakes |
spellingShingle |
Bardarbunga dike intrusion microseismicity cross-correlation rifting induced earthquakes Woods, J Winder, T White, RS Brandsdóttir, B Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland |
topic_facet |
Bardarbunga dike intrusion microseismicity cross-correlation rifting induced earthquakes |
description |
Understanding dikes is vital as they serve both as bodies that build the crust and as conduits that feed eruptions, and must be monitored to evaluate volcanic hazard. During the 2014-15 Bárðarbunga rifting event, Iceland, intenseseismicity accompanied the intrusion of a ∼ 50 km lateral dike which culminated in a 6 month long eruption. We here present relocations of earthquakes induced by the lateral dike intrusion, using cross-correlated, sub-sample relative travel times. The ∼ 100 m spatial resolution achieved reveals the complexity of the dike propagation pathway and dynamics (jerky, segmented), and allows us to address the precise relationship between the dike and seismicity, with direct implications for hazard monitoring. The spatio-temporal characteristics of the induced seismicity can be directly linked in the first instance to propagation of the tip and opening of the dike, and following this - after dike opening - indicate a relationship with magma pressure changes (i.e. dike inflation/deflation), followed by a general ’post-opening’ decay. Seismicity occurs only at the base of the dike, where dike-imposed stresses - combined with the background tectonic stress (from regional extension over > 200 years since last rifting) - are sufficient to induce failure of pre-existing weaknesses in the crust, while the greatest opening is at shallower depths. Emplacement oblique to the spreading ridge resulted in left-lateral shear motion along the distal dike section (studied here), and a prevalence of left-lateral shear failure. Fault plane strikes are predominately independent of the orientation of lineations delineated by the hypocenters, indicating that they are controlled by the underlying host rock fabric. This high-resolution study provides unprecedented opportunity for comparison with both geodetic and field (frozen dike) observations, and development and consolidation of analytical and analogue models, with implications for rifting processes and real-time monitoring of magma intrusion. Seismometers ... |
format |
Article in Journal/Newspaper |
author |
Woods, J Winder, T White, RS Brandsdóttir, B |
author_facet |
Woods, J Winder, T White, RS Brandsdóttir, B |
author_sort |
Woods, J |
title |
Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland |
title_short |
Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland |
title_full |
Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland |
title_fullStr |
Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland |
title_full_unstemmed |
Evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: The 2014–15 Bárðarbunga–Holuhraun rifting event, Iceland |
title_sort |
evolution of a lateral dike intrusion revealed by relatively-relocated dike-induced earthquakes: the 2014–15 bárðarbunga–holuhraun rifting event, iceland |
publisher |
Elsevier BV |
publishDate |
2019 |
url |
https://www.repository.cam.ac.uk/handle/1810/286414 https://doi.org/10.17863/CAM.33723 |
long_lat |
ENVELOPE(-17.528,-17.528,64.635,64.635) ENVELOPE(-16.831,-16.831,64.852,64.852) |
geographic |
Bardarbunga Holuhraun |
geographic_facet |
Bardarbunga Holuhraun |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/286414 doi:10.17863/CAM.33723 |
op_doi |
https://doi.org/10.17863/CAM.33723 |
_version_ |
1788062349399162880 |