Marine seismic source

Claim 2

In marine seismic energy generating apparatus for use in a liquid medium including at least one source of seismic energy, the improvement comprising: a reflector of seismic energy positioned above said at least one source to reflect energy therefrom, said reflector including enclosure means for confining gas of sufficient volume to produce large seismic velocity change for seismic energy entering thereinto from surrounding liquid.

Claim 3

The apparatus of claim 1 wherein the gas transmits seismic energy at a velocity of less than 1,300 feet per second.

Claim 4

The apparatus of claim 1, wherein said reflector of seismic energy further includes a large metal plate, means connected to said plate for retaining said inflatable chamber immediately below said plate, and means connected to said plate for receiving a tow line, and means connected to said plate for maintaining said plate in a substantially horizontal position as said seismic reflector is towed through the water.

Claim 5

In a marine seismic energy generating apparatus for use in a liquid medium including a source of seismic energy adapted to be actuated in said medium, the improvement comprising: a reflector of seismic energy positioned above said source to reflect energy therefrom, said reflector including enclosure means for confining gas of sufficient volume to produce a negative reflection coefficient for seismic energy entering thereinto from said liquid medium.

Claim 6

In a marine seismic energy generating apparatus for use in a liquid medium including a source of seismic energy adapted to be actuated in said medium, the improvement comprising: a reflector of seismic energy positioned above said source to reflect energy therefrom, said reflector including enclosure means for confining gas of sufficient volume to produce a negative reflection coefficient for seismic energy entering thereinto from said liquid medium.

Claim 7

An apparatus as defined in claim 1 in which said reflector is spaced from said source a distance about one-quarter wave length in said medium of seismic energy having a desired frequency in the frequency spectrum of seismic energy produced by said source of seismic energy.

Claim 8

Apparatus for generating seismic energy within a body of water which comprises a seismic energy source for operation submerged in said body of water to emit seismic energy having a preselected frequency spectrum, and seismic energy reflector means positioned above, said seismic energy source to reflect seismic energy emitted from said seismic energy source, said seismic energy reflector means containing a quantity of gas sufficient to provide said reflector means with an acoustic impedance such that the reflection coefficient presented to seismic energy hitting said reflector means from said source when said apparatus is submerged in said body of water is negative.

Claim 9

Apparatus for generating seismic energy within a body of water which comprises a seismic energy source for operation submerged in said body of water to emit seismic energy having a preselected frequency spectrum, and seismic energy reflector means positioned above, said seismic energy source to reflect seismic energy emitted from said seismic energy source, said seismic energy reflector means containing a quantity of gas sufficient to provide said reflector means with an acoustic impedance such that the reflection coefficient presented to seismic energy hitting said reflector means from said source when said apparatus is submerged in said body of water is negative.

Claim 10

An apparatus as defined in claim 3 wherein said source emits a pulse of seismic energy of a duration which is small in relation to the cycle length in water of seismic energy in said pulse having a desired frequency.