Non-double-couple earthquakes in 2017 swarm in Reykjanes Peninsula, SW Iceland: Sensitive indicator of volcano-tectonic movements at slow-spreading rift

0541510 - GFÚ 2022 RIV NL eng J - Journal Article
Hrubcová, Pavla - Doubravová, Jana - Vavryčuk, Václav
Non-double-couple earthquakes in 2017 swarm in Reykjanes Peninsula, SW Iceland: Sensitive indicator of volcano-tectonic movements at slow-spreading rift.
Earth and Planetary Science Letters. Roč. 563, June (2021), č. článku 116875. ISSN 0012-821X. E-ISSN 1385-013X
R&D Projects: GA ČR(CZ) GA18-05053S; GA ČR(CZ) GA19-06422S; GA MŠMT LM2010008
Institutional support: RVO:67985530
Keywords : earthquake swarm * moment tensor * non-double-couple components * Reykjanes Peninsula SW Iceland * focal mechanisms * volcano-tectonic evolution
OECD category: Volcanology
Impact factor: 5.785, year: 2021
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S0012821X21001345

The analysis of the 2017 earthquake swarm along the obliquely divergent Reykjanes Peninsula plate boundary revealed the most frequent focal mechanisms corresponding to main activated fault, which relates to transform faulting of the North Atlantic Rift in Iceland. Detailed double-difference locations, focal mechanisms and non-double-couple (non-DC) volumetric components of seismic moment tensors indicate an activation of three fault segments suggesting continuous interactions between tectonic and magmatic processes. They are related to inflation/deflation of a vertical magmatic dike and comprise: (1) shearing at strike-slip transform fault with left lateral motion, (2) collapses at normal faulting with negative volumetric components due to magma/fluid escape, and (3) shear-tensile opening at oblique strike-slip faulting with positive volumetric components connected to flow of trapped over-pressurized fluids. The identification of three regimes of complex volcano-tectonic evolution in divergent plate movement proves an enormous capability of the non-DC volumetric components to map tectonic processes in such settings.
Permanent Link: http://hdl.handle.net/11104/0319073