Pasadena Very-Broad-Band System and Its Use for Real-time Seismology

As a joint project between California Institute of Technology, The University of Southern California, The United States Geological Survey, and The Incorporated Research Institutions for Seismology, a very broadband seismograph system was installed in November 1987 at the Kresge Laboratory of California Institute of Technology (Figure 1). The system consists of a 3-component Wielandt-Streckeisen seismometer, Kinemetrics FBA-3 accelerometer and a Quanterra 24-bit data logger with telephone dial-up capability. The system is essentially similar to the one developed by Steim (1985) and installed at the Harvard Observatory, Massachusetts. One significant difference is a 3-component strong-motion data channel which is added to obtain on-scale recordings of large regional earthquakes. The overall dynamic range is about 200 db. The response of the system is approximately flat in velocity over a period range from 0.2 to 370 sec. The sampling interval is 20 samples per second