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125 Years of Sound Science, serving society

CMB - Columbia College, Columbia, CA, USA

Station Name CMB (CMBB)
In Operation 1986/10/25 00:00:00 - Present
Elevation: 697.00 meters
Instrumentation Broadband

  • Site


    Site is located on the campus of Columbia College in Sonora, California. This site was established to relocate instrumentation from the JAS1 in Jamestown.

    CMB was upgraded with partial funding from the IRIS Consortium and data are archived at the IRIS Data Management Center as well as the NCEDC. CMB is also a cooperative station with the Advanced National Seismic System.


    BK, BARD (Berkeley Digital Seismic Network and Bay Area Regional Deformation Network)


    Paleozoic marine limestone

    Vault/Borehole Conditions

    The vault is a buried fiberglass cylinder, eight feet in diameter and six feet deep. It has a flat top at grade level with a hatch for entry. The floor is concrete poured directly on rock. The datalogger and supporting equipment are located in an air conditioned trailer located about 70 feet from the vault and connected via underground conduits. The seismometers are thermally insulated with 4" of polyurethane foam and the top of the vault is covered with bark for additional insulation.

    GPS Monument Description

    Poured concrete cylinder with steel reinforcement
  • Plots & Figures

    Seismic Station Pictures

    Site of CMB vault

    Site of CMB vault

    STS-1 installation at CMB

    STS-1 installation at CMB

    GPS Station Timeseries

    Time series processing at the BSL

    Last year Clean Clean & detrended Raw Raw & detrended
    Lifetime Clean Clean & detrended Raw Raw & detrended
    Text file (final results only) Clean Raw

    GPS Station Pictures





  • Instrumentation

    Table of Seismic Instrumentation

    SensorDataloggerSEED ChannelsLocation
    BroadbandStreckeisen STS-1/E300 VBB Feedback SeismometerQ330HR-GFEBH?,HH?,LH?,VH?00
    AccelerometerKinemetrics FBA ES-T Accel. GFE (2 g max 10 v/g)Q330HR-GFEHN?00
    GPSTopcon Net-G3AAshtech Choke-RingSCIGN Tall-
    SensorDataloggerSEED ChannelsLocation
  • Data & Metadata

    Waveforms and associated metadata, and GPS data, are available at the Northern California Earthquake Data Center (NCEDC).

    Waveform Data

    GPS Data

  • Data Quality

    Noise Analysis

    View more noise plots

    GPS Data Quality


    Data completeness is defined both as "Completeness of observations" and "Cycle slips per observation". "Completeness of Obs." is the number of epochs in the final RINEX file normalized to the expected number. This percentage will go down if time is missing from the RINEX file. "Cycle slips per Obs." is the total number of detected cycle slip normalized to the total number of observations in the RINEX file. This number will increase as the receiver loses lock on satellites more frequently.

    Previous Year
    CMBB completeness last year
    CMBB completeness lifetime


    The effects of multipath on the data are estimated by parameters for L1 and L2 (MP1 and MP2 respectively); see Estey and Meertens (GPS Solutions, 1999) for derivation. The daily value is the RMS of MP1 and MP2 throughout the day and for all satellites. Higher values indicate a greater prevalence and/or strength of multipathing, i.e. objects on the ground are providing multiple reflection pathways from the satellite to antenna.

    Previous Year
    CMBB multipath last year
    CMBB multipath lifetime