1. A method, comprising: generating a series of scans for a subsurface; forming a series of subsurface images comprising pixels using the series of scans; creating a derivative image comprising pixels using the series of subsurface images, wherein each pixel or pixel cluster of the derivative image represents the derivative of values of the pixel or pixel cluster in the series of subsurface images; performing one or more tests on the pixels or pixel clusters of the derivative image; and detecting a subsurface object based on the one or more tests.