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Insights Into the Stress Field Around Bár ð arbunga Volcano From the 2014/2015 Holuhraun Rifting Event
Author(s) -
Spaans Karsten,
Hooper Andrew
Publication year - 2018
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2017jb015274
Subject(s) - geology , dike , seismology , rift , volcano , stress field , lava , rift zone , interferometric synthetic aperture radar , lava field , cinder cone , petrology , synthetic aperture radar , tectonics , remote sensing , physics , finite element method , thermodynamics
The two weeklong rifting event at Bárðarbunga volcano in 2014 led to the Holuhraun eruption, which produced 1.5 km 3 of lava and was the largest in Iceland in over 200 years. Predicting when and where an intrusion will lead to eruption requires detailed knowledge of the underlying stress field. Previous studies have explained the dike propagation path with a model that includes a tectonically induced stress field set up by a uniform amount of plate spreading across a straight rift axis. Here we test this hypothesis by modeling the tractions acting on the dike walls, constrained by data from Global Navigation Satellite System and Interferometric Synthetic Aperture Radar. Our results show that the majority of the opening and shearing in the final two dike segments is due to stresses built up by plate spreading since the last eruption at Holuhraun, as expected, but that the tectonically induced stress magnitude must be much lower to explain the movement of the dike walls further south. This result implies that most of the tectonically induced stress beneath the ice cap has been released, presumably due to intrusions associated with the Bárðarbunga volcanic system and the nearby Grímsvötn volcanic system, which have not been detected due to their subglacial nature. Modeling of the 2014 Bárðarbunga rifting event therefore not only yields insights into the event but also provides a window into undetected volcanic activity in the past.