--- tags: geol 420 website page --- # Electrical Resistivity Summary Here we collect together a list of key ideas you should be thinking about: - Why can sending electrical current into the ground be useful *at all* to a geologist? - Why do you we keep talking about *resistivity*, is that really something different than resistance? Why don't we do *electrical resistance* surveys? - How do you make a single electrical resistivity measurement? - How do you increase resolution vertically or laterally? - How is *resistance* converted to *resistivity* in our surveys? - What are the basic electrical resistivity array styles? What are their relative advantages and disadvantages? i.e. why/when would you use one over another? (this includes 1D vs 2D vs 3D) - What is a case where electrical resistivity doesn't work? - How deep can you interrogate the subsurface? - What are mechanism(s) by which electrical current is conducted through the subsurface?