| Popis: |
The mining area of Kalgoorlie-Boulder in Western Australia has been seismically active since at least 1920. Seismographs were installed in the area in 1964 to monitor tremors which were frequently associated with damage in the mines. For a period of seven years, mining authorities submitted reports of felt tremors and damage in the mines which were correlated with recorded seismograph events. The recorded events in the vicinity of Kalgoorlie are probably rockbursts for the following reasons: instrumental evidence and reports of damage locate the events in the mined area; minor earthquakes have rarely occurred in the region outside the mined area; strain release was fairly constant as was the rate of mining activity; first ground motions recorded on both sides of the mined area were dilatations, suggesting the ground movement is towards the centre of the mining excavations. To 31 December 1971 the maximum recorded Richter magnitude was 3.8. |
