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Strike‐slip faulting during the 2014 Bárðarbunga‐Holuhraun dike intrusion, central Iceland
Author(s) -
Ágústsdóttir Thorbjörg,
Woods Jennifer,
Greenfield Tim,
Green Robert G.,
White Robert S.,
Winder Tom,
Brandsdóttir Bryndís,
Steinthórsson Sveinbjörn,
Soosalu Heidi
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl067423
Subject(s) - geology , dike , seismology , induced seismicity , rift , volcano , focal mechanism , rift zone , intrusion , slip (aerodynamics) , petrology , tectonics , physics , geochemistry , thermodynamics
Over a 13 day period magma propagated laterally from the subglacial 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 h. During each surge forward, seismicity behind the dike tip dropped. Moment tensor solutions from the leading edge show exclusively left‐lateral strike‐slip faulting subparallel 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.