Abstract: An electric actuated explosion detonator for use to detonate a confined explosive charge capable of being detonated by heat and/or shock, including an electrical resistor positioned in engagement with the confined explosive charge, the resistor having two electrical contacts and having a predetermined maximum electric current carrying capability and subject to receiving, by the application of an electrical energy source, sufficient voltage and wattage that an instantaneous current flow causes the resistor to instantaneously disintegrate.

Abstract: An assembly is provided for generating seismic signals in the earth utilizing one or more shells. A tubular barrel made of frangible material, such as plastic, has a shell positioned within it, the shell having a head with an electrically actuated primer button. A continuity block is positioned within the barrel providing electrical continuity with the shell and the primer button. Conductors are connected to the continuity block and extending exteriorly of the barrel, the shell being fired by connecting the conductors to a voltage source. The barrel may be elongatd to house a plurality of spaced apart shells, the first shell being electrically fired and the other shells being fired by percussion. Each percussion shell is engaged by a plunger which is actuated by the slug fired from the adjacent shell so that upon firing of the electric shell, the slug thereof fires the first percussion shell and each percussion shell thereafter is fired in sequence.

Abstract: A transportable seismic energy source having a baseplate for contacting the earth, an upper master cylinder affixed at its lower end to the base plate and extending uprightly from it, a receiving cylinder of outside diameter less than the internal diameter of the master cylinder and supported coaxially within the upper portion of the master cylinder, the master cylinder and receiving cylinder being filled with liquid, a slug firing gun mounted to the master cylinder and arranged so that the gun muzzle extends coaxially and above the receiving cylinder.

Abstract: An improved portable seismic energy source including a base member having cylindrical sidewalls and an open lower end for resting on the earth's surface, a horizontal baseplate secured to the base member upper end, the baseplate having a central opening therein, a gun mounted on the horizontal baseplate for firing a projectile through the opening therein to impact the earth's surface and generate a seismic signal, a spatter plate mounted to the base member such as by means of a vertical cylinder secured to the lower surface of the baseplate with the lower end of the cylinder being affixed to the spatter plate, the spatter plate having an opening therein in register with the cylinder so that a projectile fired passes through the opening, the spatter plate being positioned above the earth's surface, and a flexible diaphragm secured at its periphery to the lower circumferential surface of the base member and having a central opening therein, the diaphragm being stretched over the top of the spatter plate, the sp

Abstract: A method of generating a seismic signal by forming a shallow hole in the earth's surface, at least partially filling the hole with liquid, positioning a projectile firing apparatus over the hole and firing a projectile downward into the hole impacting the liquid therein.

Abstract: A portable seismic energy source having a base for resting on the earth's surface, a gun providing a means of firing a projectile to impact the earth and generate a seismic signal and a ball and socket to mount the gun on the base to permit the projectile fired by the gun to strike the surface of the earth at a selectable angle.

Abstract: An improved seismic energy source having a base with an opening therethrough and having a gun mounted on the base for firing a projectile to impact on the earth's surface and generate a seismic signal, the improvement including a spatter plate and a flexible diaphragm affixed at its periphery to the base lower end, the diaphragm having an opening through which the projectile fired by the gun passes, the diaphragm serving to keep the base chamber free of compacted soil kicked up when the projectile impacts the earth and to contain and quiet the muzzle blast.

Abstract: A lightweight, mobile, low-energy seismic source comprises an industrial shotgun, having a solid projectile combined with a base structure to support the gun in a substantially vertical position, slightly above the surface of the earth. The muzzle velocity of the projectile is sufficiently high that it can provide up to 9,000 foot pounds of energy impacting on the earth, which is comparable to that of some of the larger weight drop machines. Wheels or carrying bars can be provided for manual transport of the source.