Sponsor: DOE/Energy Efficiency and Renewables/Enhanced Geothermal Systems
Start_Date: 6/7/2004
End_Date: 7/7/2004
Lat: na
Long: na
Descr: We wish to use R130 loggers to record magnetotelluric (MT) time series for about a month in the Coso geothermal system, eastern CA. We are looking for subsurface changes in electrical resistivity associated with a large injection experiment in the geothermal field. We have been working with an MT contractor Quantec Geoscience, who has already interfaced its MT analog front ends with a borrowed pair of loggers from Reftek and obtained high quality test MT data. They next ordered 10 such loggers from Reftek but it looks like these will not be ready in time. Quantec will use the analog front ends on the loggers we are requesting here, but the loggers themselves will not be modified. One of our general goals is to bring about a convergence in MT and seismic instrumentation. We are quite excited about the possibility of creating a small fleet of MT loggers based on the Reftek technology. Quantec has agreed with Reftek that Reftek will maintain their MT instruments and the MT time series are being archived in SEED format. Quantec has already gained experience with the format by unwrapping the permanent observatory data of Parkfield and using it as a remote reference for general MT surveying, in particular our NSF-funded transect of the Great Basin-Colorado Plateau transition and the DOE transect of the Central Nevada seismic belt. Wannamaker, P. E., et al., 2004, Magnetotelluric surveying and monitoring at the Coso geothermal area, California, in support of the Enhanced Geothermal Systems concept: survey parameters and initial results, Proc. workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA, SGP-TR-175, 8 pp.
