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Physically Consistent Modeling of Dike-Induced Deformation and Seismicity: Application to the 2014 Bárðarbunga Dike, Iceland

Heimisson, Elías R. and Segall, Paul (2020) Physically Consistent Modeling of Dike-Induced Deformation and Seismicity: Application to the 2014 Bárðarbunga Dike, Iceland. Journal of Geophysical Research. Solid Earth, 125 (2). Art. No. e2019JB018141. ISSN 2169-9313. https://resolver.caltech.edu/CaltechAUTHORS:20200409-095534661

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Abstract

Dike intrusions are often associated with surface deformation and propagating swarms of earthquakes. These are understood to be manifestations of the same underlying physical process, although rarely modeled as such. We construct a physics‐based model of the 2014 Bárðarbunga dike, by far the best observed large dike ( >0.5 km³) to date. We constrain the background stress state by the total dike deformation, the time‐dependent dike pressure from continuous GPS and the extent of the seismic swarm, and the spatial dependence of frictional properties via the space‐time evolution of seismicity. We find that the geodetic and earthquake data can be reconciled with a self‐consistent set of parameters. The complex spatial and temporal evolution of the Bárðarbunga seismicity can be explained by dike‐induced elastic stress changes on preexisting faults, constrained by observed focal mechanisms. In particular, the model captures the segmentation of seismicity, where only the newest dike segment is seismically active. Our results indicate that many features of the seismicity result from the interplay between time‐dependent magma pressure within the dike and stress memory effects. The spatial variability in seismicity requires heterogeneity in frictional properties and/or local initial stresses. Modeling suggests that the dike pressure drops during rapid advances and increases during pauses, which primarily causes the segmentation of the seismicity. Joint analysis of multiple data types could potentially lead to improved, physics‐based eruption forecasts.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1029/2019jb018141DOIArticle
ORCID:
AuthorORCID
Heimisson, Elías R.0000-0001-8342-7226
Segall, Paul0000-0001-5973-471X
Additional Information:© 2020 American Geophysical Union. Received 1 JUN 2019; Accepted 22 JAN 2020; Accepted article online 26 JAN 2020. We thank Tim Greenfield, Bob White, and Thorbjörg Águstsdóttir for providing access to earthquake locations and magnitude estimates prior to publication. We also thank Sigrún Hreinsdóttir for providing the 8 hr GPS time series and Andy Hooper for the processed and downsampled interferograms. We thank Jean‐Luc Got and an anonymous reviewer for their constructive remarks. All data used in this study can be found under following references (Ágústsdóttir et al., 2019; Greenfield et al., 2018; Sigmundsson et al., 2015). This research was supported by NASA under the NASA Earth and Space Science Fellowship Program (Grant NNX16AO40H) and NASA ROSES ESI (Grant NNX16AN08G).
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NASA Earth and Space Science FellowshipNNX16AO40H
NASANNX16AN08G
Subject Keywords:dike propagation; rate‐and‐state friction; joint inversion; volcanoes; seismicity; geodesy
Issue or Number:2
Record Number:CaltechAUTHORS:20200409-095534661
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20200409-095534661
Official Citation:Heimisson, E. R., & Segall, P. (2020). Physically consistent modeling of dike‐induced deformation and seismicity: Application to the 2014 Bàrðarbunga dike, Iceland. Journal of Geophysical Research: Solid Earth, 125, e2019JB018141. https://doi.org/10.1029/2019JB018141
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102430
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:09 Apr 2020 17:13
Last Modified:03 Aug 2020 19:07

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