Tectonic stress changes related to plate spreading prior to the 2021 Fagradalsfjall eruption in SW Iceland

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F23%3A00570375" target="_blank" >RIV/67985530:_____/23:00570375 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0040195123000598" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0040195123000598</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.tecto.2023.229761" target="_blank" >10.1016/j.tecto.2023.229761</a>

Result language

angličtina

Original language name

Tectonic stress changes related to plate spreading prior to the 2021 Fagradalsfjall eruption in SW Iceland

Original language description

The Reykjanes Peninsula in SW Iceland is a part of the Mid-Atlantic plate boundary. It forms its transtensional segment with several volcanic and faulting systems. We focus on the 2017 seismicity that occurred in the central part of Reykjanes at the place of the Fagradalsfjall volcano prior to its eruption on March 19, 2021. We invert well-determined focal mechanisms of the 2017 seismicity and provide mapping of tectonic stress in space and time. Our results disclose heterogeneous stress field manifested by mix of shear, tensile and compressive frac-turing. The prominent stress direction was in the azimuth of 120 degrees +/- 8 degrees, which represents the overall extension related to rifting in the Reykjanes Peninsula. The activity initiated on the transform fault segment with pre-dominantly shear strike-slip events. The non-shear fractures occurred later being associated with normal dip-slips and corresponding to the opening of volcanic fissures trending in the azimuth of 30-35 degrees, perpendicular to the extension. The dip-slips were mainly located above an aseismic dike detected in the centre of the 2017 swarm. This dike represents a zone of crustal weakening during a preparatory phase of the future 2021 Fagradalsfjall volcanic eruption located at the same place. Moreover, we detected local variation of stress when the stress axes abruptly interchanged their directions in the individual stress domains. These stress changes are interpreted in a consequence of plate spreading and upcoming fluid flow during a preparatory phase of a rifting episode.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10507 - Volcanology

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Tectonophysics

ISSN

0040-1951

e-ISSN

1879-3266

Volume of the periodical

851

Issue of the periodical within the volume

March

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

12

Pages from-to

229761

UT code for WoS article

000949803200001

EID of the result in the Scopus database

2-s2.0-85149177988