Moment tensors of induced microearthquakes in The Geysers geothermal reservoir from broadband seismic recordings: Implications for faulting regime, stress tensor, and fluid pressure.

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F18%3A00494895" target="_blank" >RIV/67985530:_____/18:00494895 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1029/2018JB016251" target="_blank" >http://dx.doi.org/10.1029/2018JB016251</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2018JB016251" target="_blank" >10.1029/2018JB016251</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Moment tensors of induced microearthquakes in The Geysers geothermal reservoir from broadband seismic recordings: Implications for faulting regime, stress tensor, and fluid pressure.

Popis výsledku v původním jazyce

Full moment tensors of 1,421 microearthquakes in The Geysers geothermal field were calculated using waveform data from a field-wide broadband network and the approach based on the principal component analysis. Spatial characteristics of faulting regime, stress tensor and the isotropic component (ISO) of moment tensors were investigated. The studied events form different clusters dominated by normal faults (NF) and strike-slip (SS) faults, respectively. The SS-dominated clusters are related to the SS stress state observed in the southwestern side of the field where two NW-SE trending fault zones exist. Increasing proportions of SS faults were observed near the shallow and deep parts of the NF-dominated clusters. Temperature differences between the upper and lower parts of the reservoir do not change the overall stress states of clusters. The stress ratios in the NW part are much smaller than in the SE part of the field. The retrieved ISOs range between -5% and 25% for 96% of events. The average percentages of positive ISOs are correlated with the average injection rates in different clusters, and keep an increasing trend with depth below the main injection interval. Only 10% of events show negative ISO and are mainly constrained within the depth range of steam extraction. The proportion of events with negative ISO suggests much weaker seismic responses of the steam extraction than the water injection. The spatial variations of the ISO percentage do not follow the seismicity variations as the ISO is more sensitive to the pressure changes related to the fluid injection and migration.

Název v anglickém jazyce

Moment tensors of induced microearthquakes in The Geysers geothermal reservoir from broadband seismic recordings: Implications for faulting regime, stress tensor, and fluid pressure.

Popis výsledku anglicky

Full moment tensors of 1,421 microearthquakes in The Geysers geothermal field were calculated using waveform data from a field-wide broadband network and the approach based on the principal component analysis. Spatial characteristics of faulting regime, stress tensor and the isotropic component (ISO) of moment tensors were investigated. The studied events form different clusters dominated by normal faults (NF) and strike-slip (SS) faults, respectively. The SS-dominated clusters are related to the SS stress state observed in the southwestern side of the field where two NW-SE trending fault zones exist. Increasing proportions of SS faults were observed near the shallow and deep parts of the NF-dominated clusters. Temperature differences between the upper and lower parts of the reservoir do not change the overall stress states of clusters. The stress ratios in the NW part are much smaller than in the SE part of the field. The retrieved ISOs range between -5% and 25% for 96% of events. The average percentages of positive ISOs are correlated with the average injection rates in different clusters, and keep an increasing trend with depth below the main injection interval. Only 10% of events show negative ISO and are mainly constrained within the depth range of steam extraction. The proportion of events with negative ISO suggests much weaker seismic responses of the steam extraction than the water injection. The spatial variations of the ISO percentage do not follow the seismicity variations as the ISO is more sensitive to the pressure changes related to the fluid injection and migration.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

<a href="/cs/project/GC16-19751J" target="_blank" >GC16-19751J: Určení seismické anizotropie a útlumu z akustických emisí a pozorování přirozené a indukované seismicity</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Journal of Geophysical Research: Solid Earth

ISSN

2169-9313

e-ISSN

—

Svazek periodika

123

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

19

Strana od-do

8748-8766

Kód UT WoS článku

000451086200025

EID výsledku v databázi Scopus

2-s2.0-85054487624