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

DATES OF OPERATION:  	11 Sep 1989 to Present.

SEISMOMETER TYPE AND ADC:
Streckeisen Model STS-2/VBB 3 component system.  Geotech Model GS-13 seismometers
are used for the EHZ, EHN, EHE components.  ADC is Martin Marietta EDME.  

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 channels.  Range: +8,388,607 to 
-8,388,608 counts.  16 bit integer data words for very short period (100 sps),
mass position channels, and all environmental channels.  Range: +32767 to 
-32768 counts.

EVENT DETECTOR ALGORITHM:  
The Murdock event detector (Murdock, 1991) is used for the very short period data. 

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 detailed description of the IRIS-1 system can be found in Peterson et al (1989).