See the Abstract on another page.
This is a preliminary collection of digital broadband seismograms made with the STM-8 prototypes running in the basement of the farmhouse at CCMO.
The figures are all .gif images, and come out 1000+ pixels wide; I haven't found a way to get photoshop or whatever to make them fit on the screen (lt. 600 pix wide) without reducing the resolution. Any suggestions?
To PRINT THEM, from NETSCAPE, open PAGE SETUP under FILE, and set the scale to 50-60%, and rotate if necessary.
Latest event: 03 March 1998
This are the first events from the BETA seismometer which replaced the prototype on January 3.
I have added the latest broadband record at the head of this list:
-1. Latest Broadband Record , Ms = 7.3, SE of Taiwan, 03 May 1998.
1. Latest Broadband Record , Ms = 6.6, North Atlantic Ridge, 16 february 1998
2. Comparisons to other Broadband stations , Ms = 6.6, North Atlantic Ridge, 16 february 1998 (STS-1 sensors at CCM, 100 km west, and WCI, 400 km east; both stations are in caverns, and have 24-bit digital systems) The differences are due to azimuthal variations with respect to the earthquake source mechanism.
1. Broadband Record , Ms = 6.4, Guatemala; 10 January 98
2. Comparisons to other Broadband stations , Ms = 6.4, Guatemala; 10 January 98:
3. Power spectra comparisons with other Broadband Records , Ms =6.4, Guatemala; 10 January 98: The peaks in the PSD agree well in the 10 to 100 second range. With the multimeter sampling at 1 per second,the nyquist is 2 seconds.
4. Noise comparisons with other Broadband Records , Pre-Event: Ms =6.4, Guatemala; 10 January 98: This shows the power spectra for 25 minutes prior to the event; the CCMO (basement data) looks like it is from (well...) the basement. The CCM and WCI data are from caverns, and push the NLNM (New Low Noise Model) curve. The peak in the noise at 6 seconds is due to the microseism background noise.
4a. Noise comparisons on several days in September , This shows the power spectra for 4 hour random samples; the CCMO (basement data) looks like it is from (well...) the basement. The peak in the noise at 6 seconds is due to the microseism background noise.
5. Broadband Record , Ms = 7.0, Loyalty Islands; 04 January 98; first event from the BETA seismometer.
Other Data Samples:
Here is an event in Northern Tibet: The 12-bit multimeter digitizer clipped.
(These have not been loaded yet)
Geophysical Instrumentation Consultant
(since 1969)
Seismic Instrumentation Engineer at
St. Louis University,
Department of Earth and Atmospheric Sciences
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