Method and apparatus for generating seismic waves

The apparatus for generating an acoustic wave comprising:

• an elongated first cylinder having a top and bottom,
• an enclosing bottom member engaging the bottom of said first cylinder,
• an enclosing top member engaging the top of said first cylinder, and having a hole therethrough,
• a piston within said first cylinder,
• a second cylinder carried by said piston coaxially disposed within said first cylinder to define therewithin a combustion chamber of substantial length relative to said first cylinder,
• means on the opposite side of said piston from said combustion zone for containing a gas under pressure to bias said piston toward said combustion chamber,
• a piston rod carried by said piston extending through the hole in said enclosing top, said piston rod having a cavity along its axial length with at least one hole through a wall thereof outside said first cylinder to exhaust gases from the combustion chamber,
• the ratio of the diameter to the distance said piston travels being one to at least three,
• a fuel conducting tube extending along the length of said piston rod within the cavity therein to approximately the midpoint of the combustion chamber, whereby when combustion fuels are conducted to within the combustion chamber through said fuel conducting tube, the existing gases within the combustion chamber are exhausted through the cavity within said piston rod, and
• means within said gas conducting tube adjacent the top of the piston rod for igniting the combustion fuel therewithin,
• whereby said apparatus can be operated with or without initial ground surface contact and without a special mechanical reaction mass for absorbing force applied to said piston.

A method for generating seismic waves comprising:

• suspending a weight above an earth surface,
• providing a piston within an elongated cavity of said suspended weight,
• providing means for introducing a combustion fuel to within the cavity on one side of said piston, and
• igniting said combustion fuel, whereby a force is applied to move said suspended weight to impact said earth surface and to generate seismic waves therebeneath.

A method for generating seismic waves comprising:

• suspending an elongated cylinder having a centrally-located cavity therein above an earth surface,
• disposing a piston within the cavity,
• securing a piston rod carrying said piston to a mounting frame,
• igniting a combustion fuel within the cavity to move said elongated cylinder a distance of approximately three times the diameter of said piston with respect to said piston so as to apply a force to move said cylinder to impact said earth surface and to generate seismic waves therebeneath.