Strike-slip Faulting during the 2014 Bárðarbunga-Holuhraun Dike Intrusion, Central Iceland.

• Published in: Geophysical Research Letters
• Main Authors: Ágústsdóttir, Thorbjörg, Woods, Jennifer, Greenfield, Tim, Green, Robert G., White, R. S., Winder, Tom, Brandsdóttir, Bryndís, Steinthórsson, Sveinbjörn, Soosalu, Heidi
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU 2016
• Subjects: 02 - Geodynamics; Geophysics and Tectonics; Holuhraun; Iceland
• Online Access: http://eprints.esc.cam.ac.uk/3539/; http://eprints.esc.cam.ac.uk/3539/22/GRL.png; http://eprints.esc.cam.ac.uk/3539/27/-g-stsd-ttir_et_al-2016-Geophysical_Research_Letters%20final%20.pdf; http://eprints.esc.cam.ac.uk/3539/1/-g-stsd-ttir_et_al-2016-Geophysical_Research_Letters.pdf; http://eprints.esc.cam.ac.uk/3539/2/grl53988-sup-0001-supinfo.pdf; http://eprints.esc.cam.ac.uk/3539/3/grl53988-sup-0002-supinfo.txt; http://eprints.esc.cam.ac.uk/3539/4/grl53988-sup-0003-supinfo.pdf; http://eprints.esc.cam.ac.uk/3539/5/grl53988-sup-0004-supinfo.mp4; http://onlinelibrary.wiley.com/doi/10.1002/2015GL067423/full; https://doi.org/10.1002/2015GL067423

Over a 13 day period magma propagated laterally from the sub-glacial Bárðarbunga volcano in the northern rift zone, Iceland. It created > 30,000 earthquakes at 5–7 km depth along a 48 km path before erupting on 29 August 2014. The seismicity, which tracked the dike propagation, advanced in short bursts at 0.3–4.7 km/h separated by pauses of up to 81 hours. During each surge forward, seismicity behind the dike tip dropped. Moment tensor solutions from the leading edge show exclusively left-lateral strike-slip faulting sub-parallel to the advancing dike tip, releasing accumulated strain deficit in the brittle layer of the rift zone. Behind the leading edge, both left- and right-lateral strike-slip earthquakes are observed. The lack of non double-couple earthquakes implies that the dike opening was aseismic.