Abstract: A method of processing reflection seismic traces based on a D(tau, x2) diagram showing horizontal events (WAH-WDH). For each value of tau the corresponding signal amplitude is analyzed for the various x2 in a time window of less than a predetermined width. The amplitudes are subjected to conventional linear regression minimizing the sum of absolute values of discrepancies from the straight line, or the sum of their squares. Each concentration zone is swept by a straight line pivoting successively about each point with a slope equal to the square of the offset.