A second derivative method of resistivity sounding

The second vertical derivatives of gravity and magnetic potential are widely used in geophysical prospecting because of their better resolution. On the same basis an attempt has been made to obtain the expressions for the second vertical derivative of the electrical potential and to compute its nature for comparison. Derivative responses over a two-layered earth and also over an anticlinal structure have been computed and it is shown that the second vertical derivative sounding could be employed for greater accuracy in finding out the thickness of such beds or the inclination of the sides of the anticline and its depth when compared with normal resistivity sounding