27.10.2014 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Chapter 3<br />

Mining-induced Seismicity<br />

3.1 Creighton Mine Seismic Monitoring Systems<br />

Seismic monitoring <strong>of</strong>fers <strong>the</strong> best insight into current rock mass damage processes and failure<br />

related to mining-induced fault reactivation. Brittle failures can be recorded in real-time as<br />

seismic events. These can be located within an array <strong>of</strong> sensors, and source parameters can be<br />

calculated for each event.<br />

The Creighton Mine currently experiences high rates <strong>of</strong> seismicity, averaging over 70 events per<br />

day. Two seismic systems are in operation at Creighton Mine to detect <strong>the</strong>se events: The<br />

Engineering Seismology Group (ESG) Hyperion Microseismic System (HMS), and a strong<br />

motion Hyperion Digital Drum Recorder (HDDR) system.<br />

The microseismic system consists <strong>of</strong> 88 channels occupied by 10 triaxial accelerometers<br />

(consuming 3 channels each) and 49 uniaxial accelerometers, leaving 9 channels free for<br />

expansion. The HMS sensors are distributed mine-wide. The system records full waveforms,<br />

allowing for <strong>the</strong> calculation <strong>of</strong> <strong>the</strong> hypocenter location, magnitude and o<strong>the</strong>r source parameters.<br />

The HDDR system is a strong motion system and consists <strong>of</strong> one geophone on <strong>the</strong> earth surface.<br />

This system is reserved for <strong>the</strong> detection <strong>of</strong> larger magnitude events, above 0 m N on <strong>the</strong> Nuttli<br />

Scale used by <strong>the</strong> Geological Survey <strong>of</strong> Canada, which saturate <strong>the</strong> microseismic system. The<br />

HDDR system is used to obtain a magnitude for such events. Three triaxial geophones on surface<br />

40

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!