1. Digital World Wide Standardized Seismograph System - DWWSSN: [ DW ]

DATES OF OPERATION:	07 Aug 1995 to Present.

SEISMOMETER TYPE AND DATA ACQUISITION SYSTEM:
Benioff short-period vertical seismometer, Geotech Model 1051 for SHZ data.
Sprengnether long-period seismometers (one vertical Model S-5007-V previously
Model 201 and two horizontal Model S-5007-H previously Model 100) which are
used for both long-period and mid-period data.  IDA MK7 data acquisition system.

CALIBRATION EPOCH:	1995, 219 - Present

DIGITAL FORMAT:
16 bit integer data words for all components.  Range: +32,767 to -32,768 counts.

EVENT DETECTOR ALGORITHM:  
The event detector used for the SHZ channel was developed at the ASL and was 
not documented.  The mid-period channels are detected on a straight forward   
amplitude basis.

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 Digital World Wide Standardized Seismograph Network (DWWSSN)
can be found in Peterson et al (1982).