geophysical studies site b geophysical studies progress osper project site b bruce smith robert...
TRANSCRIPT
GEOPHYSICAL STUDIES SITE B
GEOPHYSICAL STUDIES PROGRESS OSPER PROJECT SITE B
BRUCE SMITHROBERT BISDORFRAY HUTTONMARK TABACHECKROBERT HORTON
GEOPHYSICAL METHODS USED
• DC RESISTIVITY SOUNDING obtain variation in electrical resistivity as a function
of depth (to about 40 meters)
• ELECTROMAGNETIC PROFILING (EM31)obtain variation in electrical conductivity as a function of position (mapping lateral variations) 3 to 6 meters
• TOTAL FIELD MAGNETICS (not discussed) geologic mapping detect magnetic metallic objects (oil field pipes etc.)
• ELECTROMAGNETIC PROFILE (EM34…not discussed)depth to 40m but very noisy due to metallic pipes
ELECTRICAL CROSS SECTION SITE B
RESISTIVITY (ohm meters) CONDUCTIVITY (millisiemens) ρ = 1000/σ(ms) σ(ms) = 1000/ρ
100 ohm meters = 10 ms