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The Seismic Spectrum. Jonathan Berger Institute of Geophysics and Planetary Physics Scripps Institution of Oceanography University of California San Diego. Earthscope - Permanent Array. Model. STS-1. KS36000I. KS5400. Type. Force Feedback. Force Feedback. Force Feedback. Geometry.
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The Seismic Spectrum • Jonathan Berger • Institute of Geophysics and Planetary Physics • Scripps Institution of Oceanography • University of California San Diego
Model STS-1 KS36000I KS5400 Type Force Feedback Force Feedback Force Feedback Geometry 1-component 3-component (ortho) 3-component (ortho) Orientation accuracy ±2˚ (with care) ±3˚ ±3˚ Output velocity velocity velocity Sensitivity ±1200 v/ms-1 ±1200 v/ms-1 ±1200 v/ms-1 Bandwidth 360 sec - 5 Hz 360 sec - 4.2 Hz 330 sec - 4.2 Hz Full Scale (V) ±20 V differential ±20 V differential ±20 V differential Full Scale (Vel) ±8e-3 ms-1 ±1.2e-2 ms-1 ±1.2e-2 ms-1 Full Scale (Acc) ±2.5e-3 ms-2 ±1.9e-2 ms-2 ±1.9e-2ms-2 GSN “Long-Period” Sensors
Model STS-2 CMG-3T GS-13 Type Force Feedback Force Feedback Moving Coil Geometry Triaxial 3-component (ortho) 3-component (ortho) Orientation accuracy ±0.3˚ at 6 sec ±3˚ ±2˚ (with care) Output velocity velocity velocity Sensitivity ±750 v/ms-1 ±1200 v/ms-1 ±1090 v/ms-1 Bandwidth 120 sec - 50 Hz 100 sec - 50 Hz 10 Hz (Brick Amp) Full Scale (V) ±20 V differential ±20 V differential ±20 V differential Full Scale (Vel) ±1.3e-2 ms-1 ±9.2e-2 ms-1 Full Scale (Acc) ±2e-2 ms-2 GSN “Short-Period” Sensors
Model FBA-23 Episensor Type FBA FBA Geometry Triaxial Triaxial Orientation accuracy ±3˚ (with care) ±3˚ (with care) Output Acceleration Acceleration Sensitivity ±0.25 v/ms-2 ±2 v/ms-2 Bandwidth 50 Hz 50 Hz Full Scale (V) ±2.5 V differential ±20 V differential Full Scale (Vel) Full Scale (Acc) ±10 ms-2 ±10 ms-2 GSN “Strong-Motion” Sensors
STS1 with bell jar KS54000 ready to go down WRAB Borehole
CMG-3T STS-2
Paroscientific Micro-barometer FBA23 EpiSensor
The GSN Station RAYN Solar powered, Borehole Seismometer
The GSN Station AAK The tunnel entrance The GSN Station AAK One of the vaults
GSN Noise Analysis • 118 GSN Stations of the IU and II networks for the year July 2001 through June 2002. • Each station-channel data segmented into hourly, 1 to 11 hour segments. • noise estimated in 50% overlapping 1/7 decade (∂f/f=0.33, ~1/2 octave) bands.
Normal Modes • Sources: ~ 20˚ • Period: 0.5 to 10 x 10-3 Hz • Amplitudes: to ~10-5 ms-2
Teleseismic Signals • Sources: >~ 3000 km • Period: 3600 sec to several sec • Amplitudes: to ~10-3 ms-2
Regional Signals • Sources: >~ 100 km • Bandwidth: ~30 sec to 10 Hz • Amplitudes: to ~10 -1 Ms-2
Local Signals • Sources: <~10 km • Bandwidth: several seconds to ~30 Hz • Amplitudes: to ~10 ms-2
Normal Modes