A source or geophone array in which elements contribute unequally. Tapered source arrays may be achieved by loading different amounts of explosives in different shotholes of a pattern, by varying the number of source impulses (pops, weight drops, etc.) or their spacing, or by varying the weighting while vertical stacking. Tapered geophone or hydrophone arrays may be achieved by varying the output of the different elements, the spacing of the elements, or (most commonly) the number of elements at each location. Array tapering is used to change the directivity pattern. Generally the attenuation in the reject region is made greater and more nearly constant but at the price of widening the major lobe (for the same number of elements and overall array size). See Figure D-15c.