Understanding the seismic signature of transtensional opening in the Reykjanes peninsula rift zone, SW Iceland
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F25%3A00603637" target="_blank" >RIV/67985530:_____/25:00603637 - isvavai.cz</a>
Result on the web
<a href="https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029566" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JB029566</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1029/2024JB029566" target="_blank" >10.1029/2024JB029566</a>
Alternative languages
Result language
angličtina
Original language name
Understanding the seismic signature of transtensional opening in the Reykjanes peninsula rift zone, SW Iceland
Original language description
We analyze seismicity and centroid moment tensors (CMTs) on the Reykjanes Peninsula, Iceland, during the early phase of a widespread unrest period that led to multiple fissure eruptions between 2021 and 2024. We use a dense temporary seismic array, together with fiber-optic distributed acoustic sensing data, and incorporate first-motion polarities into the CMT inversion to improve accuracy, generating a total of 300 robust CMT solutions for magnitudes Mw > 2.5, focusing on 83 reliable Mw > 2 . 7 earthquakes for interpretation. The CMTs predominantly exhibit shallow strike-slip faulting, with a few normal faulting events compatible with tectonic stress. Interestingly, significant positive isotropic components are resolved, contributing up to 15% of the moment release. We also develop a new high-resolution seismic catalog of 34,407 events and show that larger shallow earthquakes at the plate boundary are preceded by the slow upward migration of microearthquakes from below, suggesting that intruding magmatic fluids interact with the oblique plate boundary to trigger slow slip events. We interpret our results as the seismic response to transtensional motion at the plate boundary in the brittle upper crust under shear, in response to stress changes induced by the intrusion of pressurized fluids in the lower crust. The complex interaction of multiple subparallel dikes with the plate boundary fault contributes to a broader deformation band that accommodates both tectonic and magmatic stresses. While the location and magnitude of the CMTs correlate with reactivated surface fractures and faults, the locations of intense, deep microseismic swarms indicate the sites of future fissure eruptions.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10507 - Volcanology
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Geophysical Research-Solid Earth
ISSN
2169-9313
e-ISSN
2169-9356
Volume of the periodical
130
Issue of the periodical within the volume
1
Country of publishing house
US - UNITED STATES
Number of pages
25
Pages from-to
e2024JB029566
UT code for WoS article
001387869800001
EID of the result in the Scopus database
2-s2.0-85215815590