Seismological evidence of fault weakening due to erosion by fluids from observations of intraplate earthquake swarms
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F17%3A00475199" target="_blank" >RIV/67985530:_____/17:00475199 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1002/2017JB013958" target="_blank" >http://dx.doi.org/10.1002/2017JB013958</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1002/2017JB013958" target="_blank" >10.1002/2017JB013958</a>
Alternative languages
Result language
angličtina
Original language name
Seismological evidence of fault weakening due to erosion by fluids from observations of intraplate earthquake swarms
Original language description
The occurrence and specific properties of earthquake swarms in geothermal areas are usually attributed to a highly fractured rock and/or heterogeneous stress within the rock mass being triggered by magmatic or hydrothermal fluid intrusion. The increase of fluid pressure destabilizes fractures and causes their opening and subsequent shear-tensile rupture. The spreading and evolution of the seismic activity are controlled by fluid flow due to diffusion in a permeable rock (fluid-diffusion model) and/or by redistribution of Coulomb stress (intrusion model). These models, however, are not valid universally. We provide evidence that none of these models is consistent with observations of swarm earthquakes in West Bohemia, Czech Republic. Full seismic moment tensors of microearthquakes in the 2008 swarm in West Bohemia indicate that fracturing at the starting phase of the swarm was not associated with fault openings caused by pressurized fluids but rather with fault compactions. This can physically be explained by a fault-weakening model, when the essential role in the swarm triggering is attributed to degradation of fault strength due to long-lasting chemical and hydrothermal fluid-rock interactions in the focal zone. Since the rock is exposed to circulating hydrothermal, CO2-saturated fluids, the walls of fractures are weakened by dissolving and altering various minerals. The porosity of the fault gauge increases, and the fault weakens. If fault strength lowers to a critical value, the seismicity is triggered. The fractures are compacted during failure, the fault strength recovers, and a new cycle begins.
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
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)
Others
Publication year
2017
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
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Volume of the periodical
122
Issue of the periodical within the volume
5
Country of publishing house
US - UNITED STATES
Number of pages
18
Pages from-to
3701-3718
UT code for WoS article
000403465600026
EID of the result in the Scopus database
2-s2.0-85018379667