TY  - JOUR
ID  - epos2208
UR  - http://doi.org/10.1007/s11600-018-0215-1
IS  - 1
A1  - Leptokaropoulos, Konstantinos Michail
A1  - Staszek, Monika
N2  - 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.
VL  - 67
TI  - Temporal response of magnitude distribution to fluid injection rates in The Geysers geothermal field
AV  - none
EP  - 339
Y1  - 2019///
PB  - Versita, Warsaw and Springer-Verlag Berlin Heidelberg
JF  - Acta Geophysica
KW  - Injection-induced seismicity Magnitude distribution Geothermal fields Statistical seismology
SN  - 1895-6572
SP  - 327
ER  -