POLARIS Underground Project at SNO (P.U.P.S)
Gail M. AtkinsonEleanor Sonley
San Linn I. KakaCarleton University
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Seismic waves composed of
• Source effects– Resulting from nucleation of earthquake
• Path effects– Geometric spreading and anelastic
attenuation with distance from hypocentre
• Site effects– Amplification due to near surface rock/soil
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Purpose
• Measure attenuation due to uppermost 2 km of a hard rock site
• Frequency dependence of transmission to surface
• Free surface effects
• Measuring source effects of small earthquakes
• Teleseismic effects
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Earthquakes happen all the time
http://www.iris.edu/seismon/ Today at 2:20 pm
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Run Seismic Waves
Seismic Sources…
http://www.iris.washington.edu/edu/software.htm
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Seismic Sources…
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Instrument Locations
• 3 currently operational
9Clean Lab at 6800 Level – Junction Area
10Surface Station 1 – Rock outcrop beside warehouse
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4600 Level – former germanium detector lab
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Instrument Locations
• 3 currently operational
• Planned (remainder of this week)
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Data Collection
• Extract events of interest
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Data already collectedBlast recorded at clean lab site
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Data already collectedSame blast recorded on rock outcrop
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Data Collection
• Extract events of interest
• Exchange hard disk-Future analysis
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The SNOlab advantage
• Distant from surface effects
• Very Low noise
• Very hard rock
• 3D distribution of stations
• Existing infrastructure