title of the thesis - Department of Geology - Queen's University

3.2.1.6 Peak Acceleration Parameter, Velocity Parameter and Maximum Displacement
Calculated motion parameters include peak acceleration, peak velocity and maximum
displacement. The spatial distribution of stress parameters shows the same trends as the stress and
source dimension parameters: low parameter values are observed to the south and southeast of the
excavation; while higher parameter values are found to the southwest of the excavation, and
elevated values directly east of the excavation where blasting occurs.
3.2.2 Spatial and Temporal Event Clustering
Microseismic events tend to cluster spatially and temporally. Events that cluster in space and time
can result from a localized increase in differential stress (Mendecki, 1997). Clusters of
microseismic events typically follow a large event, such as a rockburst or a blast.
Spatial and temporal trends were studied in data surrounding the 7200, 7400 and 7530 levels.
Levels below the 7530 Level were omitted from analysis since microseismic activity reflected
development, making it difficult to distinguish between blast-induced and stress-induced events.
Event frequency is observed to increase with depth, including the number of macroseismic events.
Exceptionally high rates of seismicity on and below the 7680 Level reflect active level
development in the Deep.
Analysis is concentrated on events to the south of the 400 Orebody excavation (shown previously
in Figure 2.5). This population has good sensor coverage, exhibits low location error and occurs
away from blasts. Dense event clusters directly to the east and west of the excavation are
attributed to production blasts from outward excavation (Fig. 3.6A). Events to the north of the
excavation are located outside the network, resulting in high location errors (Fig. 3.6A). Poorly
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