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

DATES OF OPERATION:  	27 Nov 1990 to 03 Feb 1995.

SEISMOMETER TYPE AND ADC:
Geotech model 36000-i borehole seismomter.  The Geotech Model GS-13 is used for the 
very-short period data (EHZ, EHN, EHE).  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 (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 all environmental channels.  Range: +32767 to -32768

EVENT DETECTOR ALGORITHIM:  
The event detector used for the EH_ components is described in Murdock (1991).

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).  There is
no very short period data available between 04 May 1992 and 30 Oct 1992.
From February 8, 1993 to February 14, 1994 there was a Kinemetrics FBA-23
installed at ANMO (ELZ/ELN/ELE at 100 sps event triggered 418 C/m/s2)