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<br />STATION <br />Table 1 <br />IDENTIFIER LATITUDE LONGITUDE ELEVATION NAME OF STATION OWNER <br /> (feet) <br />BWK 38.928 107.537 6701 Bowie King Mine BRL <br />FGH 38.948 107.536 7201 Freeman Gulch Hubbard BRL <br />LLM 38.857 107.461 8240 Lion Mesa MCC <br />MCD 38.881 107.474 7274 Minnesota Creek Dam MCC <br />MFB 38.956 107.559 7924 Middle Forest Boundary BRL <br />SPG 38.872 107.425 8174 South of Poison Gulch MCC <br />SEF 38.874 107.390 8667 South on East Flatiron MCC <br />TCR 38.982 107.564 8483 Terror Creek Dam BRL <br />WFW 38.901 107.424 8433 West Flatiron West MCC <br />WTM 38.941 107.591 7954 West Tower Mountain BRL <br />By October, 2005, five stations of the monitoring system were in operation near the Bowie Mine <br />with a radio network transmitting most stations to the mine (near the BWK station). The additional <br />instruments were added to the network and were operational by July 1, 2006. Reconfiguration of <br />the radio network to transmit all signals to the Paonia airport took place during the third quarter of <br />2006 (July-September, 2006). During the fourth quarter events recorded on the triggered network <br />were obtained for all of the 92 days in the quarter. Portions of the Earthworm computer program <br />of the USGS are used to record the multistation data in event files. Data were available at the <br />Spokane offices of NIOSH for daily review. <br />The following table gives the correspondence between the amplitude of seismic signals, measured <br />in digital counts, and acceleration. The vertical acceleration due to the pull of the earth is <br />abbreviated as 'g'. The units are given in terms of 10-6g or micro g's. Typical noise levels on the <br />recordings are 5-15 digital counts, a figure that will decrease as electronic noise sources are <br />eliminated. Of course ground motions such as wind events, traffic, and animals will continue. <br />Multiple stations mitigate the response to these noise sources as the 'noise' events typically occur <br />on one or a few stations. <br />TABLE 2 DIGITAL COUNTS vs. ACCELERATION DUE TO GRAVITY <br />DIGITAL COUNTS MICRO g <br />(10-6 of acceleration of <br />gravity) <br />25 0.75 <br />50 1.50 <br />100 3.00 <br />200 4.96 <br />1000 29.80 <br />5000 149.01 <br />10000 298.02 <br />335544 10000 (1 % of g) <br />OBSERVATIONS