CMB - Columbia College, Columbia, CA, USA
|Station Name||CMB (CMBB)|
|In Operation||1986/10/25 00:00:00 - Present|
LocationSite 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.
NetworkBK, BARD (Berkeley Digital Seismic Network and Bay Area Regional Deformation Network)
GeologyPaleozoic marine limestone
Vault/Borehole ConditionsThe 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.
Plots & Figures
Site of CMB vault
STS-1 installation at CMB
- 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
Table of Seismic Instrumentation
Sensor Datalogger SEED Channels Location Broadband Streckeisen STS-1/E300 VBB Feedback Seismometer Q330HR-GFE BH?,HH?,LH?,VH? 00 Accelerometer Kinemetrics FBA ES-T Accel. GFE (2 g max 10 v/g) Q330HR-GFE HN? 00 Receiver Antenna Radome - GPS TopCon Net-G3A Ashtech Choke-ring SCIGN Tall - Sensor Datalogger SEED Channels Location Auxiliary AntennaCurrent Q330HR-GFE VE? 00 ClockPhase Q330HR-GFE LC?,VC? 00 ClockQuality Q330HR-GFE LC?,VC? 00 InputVoltage Q330HR-GFE VE? 00 SystemCurrent Q330HR-GFE VE? 00 SystemTemperature Q330HR-GFE VK? 00 VCOValue Q330HR-GFE VC? 00
Data & Metadata
Waveforms and associated metadata, and GPS data, are available at the Northern California Earthquake Data Center (NCEDC).
- BK Information Directory, including
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 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 Lifetime