Earthquakes and reservoir impounding: State of the art

✍ Scribed by C. Lomnitz

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 478 KB
• Volume: 8
• Category: Article
• ISSN: 0013-7952
• DOI: 10.1016/0013-7952(74)90024-6

✦ Synopsis

This review is divided into five broad questions: (1) Is there a seismic effect of reservoir impounding? (2) What are the patterns of induced seismic activity? (3) What environmental conditions predispose towards triggering of earthquakes by reservoirs? (4) What is the probable physical cause of seismic activation? (5) What avenues of research are available at this time? The following conclusions are proposed:

(1) Seismic effects of reservoir impounding are probably real in those cases where the local seismicity is low and the earthquakes occur directly below the reservoir. (2) Reservoir impounding tends to produce shallow swarm patterns of low mean magnitude.

(3) The most notable examples of activation by reservoirs have occurred in the marginal areas of stable blocks and have been associated with transitional relief, and with heating of the lower crust due to Cenozoic volcanism or intrusion. (4) The probable cause of earthquake swarms under large reservoirs is the reduction of bulk tectonic strength due to hydrostatic pressure, combined with the trigger effect of the water load in the reservoir.

(5) It is possible to propose certain tectonic criteria, combined with certain field tests, which could be of diagnostic value for the detection of earthquake-prone sites in advance of dam construction and reservoir impounding.