1. Global Seismograph Network - GSN: IRIS -2 System

DATES OF OPERATION:  	08 Jul 1991 to Present.

SEISMOMETER TYPE AND ADC:
Teledyne/geotech Model KS-54000 borehole seismometer. Gurlap CMG-3T short period seismometer
for channels HHA, HHN, HHE, SHZ, SHN, ans SHE. Kinemetrics FBA-23 Low-Gain
sensor for HLZ, HLN, HLE, LLZ, LLN and LLE components. ADC Quanterra Q-680, 12 channel.


DIGITAL FORMAT:
24 bit integer data words for all broad-band (20 sps), long period (1 sps), very long
period (0.1 sps), and ultra long period (0.01) channels.  Range: +8,388,607 to -8,388,608 
counts.  24-bit integer data words for very short period (80 sps) data continuous very short period (40 sps) data. 

EVENT DETECTOR ALGORITHM: 
The Murdock event detector (Murdock, 1991) is used for the EL_ components. 

Click on any of the following items for further information.

• Channel Data
• Amplitude Response to Ground Velocity
• Seismic Noise Study graph information
  • Seismic Noise Level - Annual
  • Seismic Noise Level - Seasonal/Diurnal

COMMENTS:
A description of the IRIS-2 system can be found in USGS Open-File Report 89-471, Peterson et al (1989).