Portable Broadband Portable Broadband SeismologySeismology

Jakarta, IndonesiaMay 11-13, 2006

Bruce BeaudoinMarcos Alvarez

Part 3: Seismometer Overview

A Simple Seismometer

Equipment Inventory:Seismometers

Sensor Manufacturer Power Natural Frequency Damping Sensitivity

STS-2 Streckeisen 50 ma @ 12vdc 0.0083 Hz

0.707 critical 1500 v/m/s

CMG-3T Guralp 100 ma @ 12vdc 0.0083 Hz

0.707 critical 1500 v/m/s

CMG3-ESP Guralp

100 ma @ 12vdc 0.033 Hz

.707 critical 2000 v/m/s

CMG-40T Guralp

50 ma @ 12vdc 0.033 Hz

0.707 critical 800 v/m/s

S-13 Teledyne Geotech passive 1.0 Hz

0.707 critical 629 v/m/s

L-4C Mark Products passive 1.0 Hz 0.707 critical

166.54 v/m/s

L-22 Mark Products passive 2.0 Hz 0.707 critical 88 v/m/s

L-28 Mark Products passive 4.5 Hz 0.707 critical 30.4 v/m/s

L-40 Mark Products passive 40 Hz 0.707 critical 22.34 v/m/s

Spectral Amplitude Response Characteristics

Equipment Inventory:Broadband Seismometers

Guralp CMG-3T

Streckeisen STS-2

Equipment Inventory:Intermediate Period

Seismometers

CMG-40T30s active feedback

CMG-ESP30s active feedback

Equipment Inventory:Short Period Seismometers

L4C1Hz

Teledyne GS-131Hz1 Element/Housing

L222Hz

Passive Sensors

Streckeisen STS-2

• Tri-Axial

• 120 Second

• Low Power

• 1500 V/m/s

Streckeisen STS-2

U 2 /3 X 1/3 ZV 1/6 X 1/2 Y 1/3 ZW 1/6 X 1/2 Y 1/3 Z

X 2 /3 U 1/6 V 1/6 WY 1/2 V 1/2 WZ 1/3 U 1/3 V 1/3 W

TransformationEquations

East

North

Vertical

TransformationEquations

X 2 /3 U 1/6 V 1/6 W

Y 1/2 V 1/2 W

Z 1/3 U 1/3 V 1/3 W

Guralp CMG-3T

• 120 Second

• Low Power

• 1500 V/m/s

Guralp CMT-3T

Guralp CMG-3ESP

• 30 Second

• Low Power

• 2000 V/m/s

Guralp CMG-40T

• 30 Second

• Low Power

• 800 V/m/s

• No locking