Abstract: A seismic signaling apparatus (100) and method for enhancing the repeatability of the generated seismic signals are disclosed. The seismic signaling apparatus (100) includes a support frame (102) having an air-gun array (114) operably mounted thereto. The air-gun array (114) includes a plurality of air-guns (118, 120, 122) that are positioned such that a tapered, heavy centered, point source seismic signal is generated upon firing of the air-gun array (114). Shock absorbing members (124) are attached to adjacent air-guns (118, 120, 122) in order to absorb the force generated by the firing of the air-gun array (114). In particular, the shock absorbing members (124) absorb the forces associated with air-gun recoil to minimize the movement of the air-guns (118, 120, 122) relative to each other and the support frame (102), thereby stabilizing the air-gun array (114) and enhancing the repeatability of the generated seismic signals.

Abstract: A marine seismic signal source apparatus and method that maximizes the usable acoustical (db) energy of the array signature in a lower frequency bandwidth. The apparatus forms a three dimensional 2.times.4.times.2 array having a plurality of 8 air guns of identical firing chamber size (10 cubic inch) operably arranged in pairs at different water depths. Firing of the guns in a top to bottom time delayed sequence shifts the frequency domain of the peak acoustical db signal to concentrate the usable seismic energy in the deeper earth formation penetrating range. The frequency boundaries of the bandwidth of the occurrence of the peak 6 db increment of acoustical power are lowered and compressed into a narrower bandwidth by the firing sequence.

Abstract: A towable marine seismic source apparatus for producing a high resolution seismic signal at relatively shallow depths for engineering surveys is disclosed. The apparatus support frame operably mounts a plurality of eight identical chambered air guns in a 2.times.4.times.2 configuration to provide a tapered, heavy centered point source. The cylindrical air guns are positioned in a horizontal orientation at a predetermined depth of 1 to 3 meters and are synchronized to fire substantially simultaneously to achieve maximum peak energy output. Two chamber sizes of individual air guns (4 cu. in. & 10 cu. in.) are in a desired range and may be preferably employed in the array configuration to produce the seismic signal having distinct signature characteristics.