the seismic spectrum
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
The Seismic Spectrum
The Seismic Spectrum
Jonathan Berger
Institute of Geophysics and Planetary PhysicsScripps Institution of OceanographyUniversity of California San Diego
Jonathan Berger
Institute of Geophysics and Planetary PhysicsScripps Institution of OceanographyUniversity of California San Diego
Earthscope - Permanent Array
Model STS-1 KS36000I KS5400
Type Force Feedback Force Feedback Force Feedback
Geometry 1-component3-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 Triaxial3-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
KS54000 ready to go down WRAB Borehole
STS1 with bell jar
CMG-3T STS-2
ParoscientificMicro-barometer
FBA23
EpiSensor
The GSN Station RAYNSolar powered, Borehole Seismometer
The GSN Station AAK
The tunnel entrance
The GSN Station AAK
One of the vaults
DGAR - Vault under construction
DGAR - The finished product
DGAR - Inside the Vault
GSN Noise Analysis118 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 secAmplitudes: 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
NormalModes
180 dB
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