Seismic anisotropy in the rift of the Reykjanes Peninsula, SW Iceland, calculated using a new tomographic method

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F21%3A00545466" target="_blank" >RIV/67985530:_____/21:00545466 - isvavai.cz</a>

Result on the web

<a href="https://link.springer.com/article/10.1007/s00024-021-02784-1" target="_blank" >https://link.springer.com/article/10.1007/s00024-021-02784-1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00024-021-02784-1" target="_blank" >10.1007/s00024-021-02784-1</a>

Result language

angličtina

Original language name

Seismic anisotropy in the rift of the Reykjanes Peninsula, SW Iceland, calculated using a new tomographic method

Original language description

A new algorithm and computer code for seismic tomography in anisotropic inhomogeneous media was developed. The new tomographic approach is a generalization of classical isotropic seismic tomography which introduces spatially and directionally varying slowness. The velocity model was considered as a stack of homogeneous blocks in contact, with each block individually parameterized using background velocities of P- and S-waves and a set of 21 anisotropy parameters. The inverse problem was solved sequentially in five steps, using the velocity model from the previous step as the starting model for the subsequent step. These steps form a chain with increasing complexity: (1) isotropic homogeneous model, (2) isotropic velocity model with vertical velocity gradient, (3) 3-D inhomogeneous isotropic velocity model, (4) 3-D inhomogeneous model with uniform anisotropy, (5) 3-D inhomogeneous generally anisotropic model. The new algorithm was applied to real bulletin data of 18 seismic stations deployed in SW Iceland and operated favourably for the monitoring of local swarm-like seismicity. Next, the resolution, robustness and accuracy of the inversion were discussed using real and synthetic data. Real data inversion revealed a predominantly depth-dependent isotropic velocity background and additional general 3-D anisotropy. The parameterization of the medium was too flexible to allow for a reliable interpretation of the anisotropy inside the elementary blocks and a cluster analysis was applied to stabilize the inversion results. Three important clusters were identified as a result. The orientation of the anisotropy (fast and slow P-wave propagation directions) of two clusters coincided with the strike of the documented faults. The orientation of the anisotropy in the third cluster was interpreted as a consequence of the fluid dynamics around Kleifarvatn Lake. The P-wave anisotropy strength reached a value of ± 5–8%.

Czech name

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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

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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

2021

Confidentiality

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

Name of the periodical

Pure and Applied Geophysics

ISSN

0033-4553

e-ISSN

1420-9136

Volume of the periodical

178

Issue of the periodical within the volume

8

Country of publishing house

CH - SWITZERLAND

Number of pages

33

Pages from-to

2871-2903

UT code for WoS article

000664824700002

EID of the result in the Scopus database

2-s2.0-85108647619