Abstract: The passive microseismic record first-break enhancement method accepts a manually picked microseismic event first break from a raw record and associated pick time. The pick time is then saved as tr. A cross-correlation of all distinct trace pairs of the raw record is performed. Next, the method picks and saves the timing (dti) of the maximum value of the i-th cross-correlation for all i=1, . . . , N. Then, the maxima of the cross-correlations at t=0 are aligned by applying a shift of dti to each i-th cross-correlation. The aligned cross-correlations are then stacked to produce a stacked, aligned cross-correlation that has an enhanced SNR. The enhanced traces are produced by shifting the stacked, aligned cross-correlation by an amount of tm=tr+dtrm, where dtrm indicates the timing of the maximum value of the cross-correlation between the m-th trace and the reference trace.