La séismicité provoquée au réservoir LG-2

The construction of a rock and earth-filled dam in the La Grande River valley, Quebec has created a hydroelectric reservoir with a maximum depth of 145 m and a volume of 61.7 × 10 9 m 3 . No seismicity in this Precambrian Shield region above magnitude 0.1 was observed in the reservoir zone in the 27...

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Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Authors: Buchbinder, G. G. R., Anglin, F. M., McNicoll, Roger
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1981
Subjects:
Online Access:http://dx.doi.org/10.1139/e81-064
http://www.nrcresearchpress.com/doi/pdf/10.1139/e81-064
Description
Summary:The construction of a rock and earth-filled dam in the La Grande River valley, Quebec has created a hydroelectric reservoir with a maximum depth of 145 m and a volume of 61.7 × 10 9 m 3 . No seismicity in this Precambrian Shield region above magnitude 0.1 was observed in the reservoir zone in the 27 months preceding the filling. Microearthquakes of magnitude less than 1 started under the reservoir when a water depth of 90 m was reached after 30 days and this activity continued for about 3 months. A second series of microearthquakes began in the same active zone when the rate of filling increased twofold. The seismically active area is confined to a zone 4 km × 7 km and no deeper than 5 km. The microearthquakes are considered to be the result of minor reactivation of old faults under the reservoir in response to the increased pore pressure.