Effective Stress Drop of Earthquake Clusters
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F17%3A10363702" target="_blank" >RIV/00216208:11310/17:10363702 - isvavai.cz</a>
Výsledek na webu
<a href="http://dx.doi.org/10.1785/0120170035" target="_blank" >http://dx.doi.org/10.1785/0120170035</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1785/0120170035" target="_blank" >10.1785/0120170035</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Effective Stress Drop of Earthquake Clusters
Popis výsledku v původním jazyce
The static stress drop is a standard measure of the average decrease of shear stress on a fault during an earthquake. It has been observed that stress drop does not vary significantly with earthquake magnitude and may be regarded as an invariant parameter of the rupture process at different scales. Although typical stress drops of earthquakes range between 1 and 10 MPa, much smaller stress drops in fractions of MPa are reported for slow earthquakes and in some cases also for earthquake swarms. For the latter cases, the effective stress drop was introduced as an alternative parameter that makes use of the cumulative seismic moment and total activated area of the seis-mic cluster. In this article, we test how the effective stress drop is comparable to the static stress drop of a single earthquake rupturing the same fault portion. To this pur-pose, we compare the spatiotemporal evolution of the seismic moment release and analyze the uncertainties of the estimated stress drops. We show that the effective stress drop is only comparable to earthquake stress drops in specific cases. In particu-lar, the effective stress-drop values significantly underestimate the earthquake stress drops in the presence of aseismic deformation. The values are only scale independent if prestress and poststress conditions are uniform in space. Our analysis of data from injection-induced seismicity, natural earthquake swarms, and aftershock sequences shows that in most cases the effective stress-drop estimate is rather stable during the cluster evolution. However, slightly increasing estimates for injection-induced seismicity are indicative for the local forcing of the system. Although the effective stress drops of natural and induced seismicity in geothermal projects range from 0.1 to 3 MPa, those related to fracking in hydrocarbon formations are anomalous low, from 0.08 to 1.8 kPa, which hints to the important role of aseismic deformations.
Název v anglickém jazyce
Effective Stress Drop of Earthquake Clusters
Popis výsledku anglicky
The static stress drop is a standard measure of the average decrease of shear stress on a fault during an earthquake. It has been observed that stress drop does not vary significantly with earthquake magnitude and may be regarded as an invariant parameter of the rupture process at different scales. Although typical stress drops of earthquakes range between 1 and 10 MPa, much smaller stress drops in fractions of MPa are reported for slow earthquakes and in some cases also for earthquake swarms. For the latter cases, the effective stress drop was introduced as an alternative parameter that makes use of the cumulative seismic moment and total activated area of the seis-mic cluster. In this article, we test how the effective stress drop is comparable to the static stress drop of a single earthquake rupturing the same fault portion. To this pur-pose, we compare the spatiotemporal evolution of the seismic moment release and analyze the uncertainties of the estimated stress drops. We show that the effective stress drop is only comparable to earthquake stress drops in specific cases. In particu-lar, the effective stress-drop values significantly underestimate the earthquake stress drops in the presence of aseismic deformation. The values are only scale independent if prestress and poststress conditions are uniform in space. Our analysis of data from injection-induced seismicity, natural earthquake swarms, and aftershock sequences shows that in most cases the effective stress-drop estimate is rather stable during the cluster evolution. However, slightly increasing estimates for injection-induced seismicity are indicative for the local forcing of the system. Although the effective stress drops of natural and induced seismicity in geothermal projects range from 0.1 to 3 MPa, those related to fracking in hydrocarbon formations are anomalous low, from 0.08 to 1.8 kPa, which hints to the important role of aseismic deformations.
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10505 - Geology
Návaznosti výsledku
Projekt
Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.
Návaznosti
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Ostatní
Rok uplatnění
2017
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Bulletin of the Seismological Society of America
ISSN
0037-1106
e-ISSN
—
Svazek periodika
107
Číslo periodika v rámci svazku
5
Stát vydavatele periodika
US - Spojené státy americké
Počet stran výsledku
11
Strana od-do
2247-2257
Kód UT WoS článku
000412920500020
EID výsledku v databázi Scopus
—