Lecture 5 - Electrical Resistivity

Question 1

What are vertical electrical soundings (VES) used for?

Answer 1

Used for investigating horizontal surfaces/interfaces. Two electrodes (current electrodes) are set up to deliver current into the ground and a further two electrodes (potential electrodes) measure resistivity

Question 2

What are the two kinds of resistivity array?

Answer 2

Wenner – keep spacing between current and potential electrodes identical. Used to determine vertical structures
Schlumberger – spacing between two potential electrodes is much shorter than current-current, and potential current spacing

Question 3

In horizontal resistivity what does constant separation traversing (CST) mean?

Answer 3

Electrodes move sideways along a traverse line where spacing never changes