TY  - JOUR
ID  - epos1268
UR  - http://dx.doi.org/10.1785/0120120036
IS  - 6
A1  - Convertito, Vincenzo
A1  - Maercklin, N.
A1  - Sharma, N.
A1  - Zollo, Aldo
N2  - The growing installation of industrial facilities for subsurface exploration worldwide requires continuous re?nements in understanding both the mechanisms by which seismicity
is induced by ?eld operations and the related seismic hazard. Particularly in proximity of
densely populated areas, induced low-to-moderate magnitude seismicity characterized by high-frequency content can be clearly felt by the surrounding inhabitants and, in some cases, may
produce damage. In this respect we propose a technique for time-dependent probabilistic
seismic-hazard analysis to be used in geothermal ?elds as a monitoring tool for the e?ects
of on-going ?eld operations. The technique integrates the observed features of the seismic-
ity induced by ?uid injection and extraction with a local ground-motion-prediction equation.
The result of the analysis is the time-evolving probability of exceedance of peak ground acceleration, which can be compared with selected critical values to manage ?eld operations.
To evaluate the reliability of the proposed technique, we applied it to data collected in The
Geysers geothermal ?eld in Northern California between 1 September 2007 and 15 November
2010. We show that in the period considered the seismic hazard at The Geysers was variable
in time and space, which is a consequence of the ?eld operations and the variation of both
seismicity rate and b-value. We conclude that, for the exposure period taken into account
(i.e., 2 months), as a conservative limit, peak ground acceleration values corresponding to the
lowest probability of exceedance (e.g., 30%) must not be exceeded to ensure safe ?eld operations. We suggest testing the proposed technique at other geothermal areas or in regions where
seismicity is induced, for example, by hydrocarbon exploitation or carbon-dioxide storage.
VL  - 102
TI  - From Induced Seismicity to Direct Time-Dependent Seismic Hazard
AV  - none
EP  - 2573
Y1  - 2012/12//
PB  - Seismological Society of America
JF  - Bulletin of the Seismological Society of America
KW  - hazard
KW  -  induced seismicity
KW  -  geothermal
KW  -  The Geysers
SN  - 0037-1106
SP  - 2563
ER  -