relation: https://episodesplatform.eu/eprints/2208/
title: Temporal response of magnitude distribution to fluid injection rates in The Geysers geothermal field
creator: Leptokaropoulos, Konstantinos Michail
creator: Staszek, Monika
subject: Collective properties of seismicity
subject: Geysers
subject: Geothermal energy production
description: The influence of fluid injection rates on the magnitude distribution of the seismicity which occurred in the NW part of The Geysers geothermal site is studied here. A direct comparison between injection rate changes and b value response is attempted after appropriate selection of data subsets. Due to the relatively small sample (1121 events, corresponding to an average rate of ~ 0.45 events/day), we also aggregated seismic activity into two families corresponding to increasing and decreasing injection rates, respectively. The b values were calculated as a function of time lag related to the injection activity. In agreement with previous studies, we found a statistically significant direct relation between b values and injection rate changes, which occurred at a zero or very short time lag (from 0 to ~ 15 days). However, the b value changes are related to the slope (i.e., the second derivative of injection volume), instead of the absolute values of injection rates. The increasing injection rates correspond to b = 1.18 ± 0.06, whereas the decreasing injection rates correspond to b = 1.10 ± 0.05. The corresponding values estimated by the repeated medians technique are b = 1.97 ± 0.20 and b = 1.50 ± 0.13. Both differences are significant at 0.05 level.
publisher: Versita, Warsaw and Springer-Verlag Berlin Heidelberg
date: 2019
type: Article
type: NonPeerReviewed
identifier:   Leptokaropoulos, Konstantinos Michail and Staszek, Monika  (2019) Temporal response of magnitude distribution to fluid injection rates in The Geysers geothermal field.  Acta Geophysica, 67 (1).  pp. 327-339. DOI: https://doi.org/10.1007/s11600-018-0215-1 <https://doi.org/10.1007/s11600-018-0215-1>     
relation: http://doi.org/10.1007/s11600-018-0215-1
relation: doi:10.1007/s11600-018-0215-1