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

DATES OF OPERATION:  	18 Jun 1991 to Present.

SEISMOMETER TYPE AND ADC:
Streckeisen Model STS-1/VBB 3 component system.  Kinemetrics Model FBA-23 
low-gain sensor for channels ELZ, ELN, and ELE.  ADC is Martin Marietta EDME.

DIGITAL FORMAT:
24 bit integer data words for all broadband (20 sps), long period (1 sps), very
long period (0.1 sps), and ultra triggered long period (0.01 sps) channels.  
Range: +8,388,607 to -8,388,608 counts.16 bit integer data words for very short  
period (100 sps), mass position and environmental channels.  Range: +32767 to 
32768 counts.

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