Spatial distribution of microseisms at Turtle Mountain

Zuolin Chen, Robert R. Stewart, Henry C. Bland, Jeffrey Blair Thurston

Comparison between the distributions of the microseismic events and topography, tectonic weaknesses and the historic mine works suggests that movement along thrust faults and induced fractures within the hanging walls of thrust faults may be the source of ongoing microseismicity in the region. Generally, these events are related to steep topography above surface exposures of thrust faults on the mountain's flanks. Further anecdotal evidence for this is the observation of rockslides on only the steep eastern flank. No microseismic hypocentre locations are on, or below, the gentle lower portions of northern and southern flanks. Further, swarms of events have been observed. These tend to originate from sources 1-1.5 km deep beneath the surface of the Frank Slide debris. A relatively few microseismic events correspond to the remaining mine works.