Method, source array and source element that generate seismic waves. The source element includes an enclosure having an opening covered by a piston; a local supply accumulator fluidly communicating with an interior of the enclosure, a pressure of the fluid inside the local supply accumulator being larger than a pressure of the fluid inside the enclosure; a local supply valve located between the local supply accumulator and the enclosure and configured to control a flow of the fluid from the local supply accumulator to the interior of the enclosure; and a controller configured to control the local supply valve such that the pressure inside the enclosure does not fall below a first preset value based upon an ambient pressure of the enclosure while seismic waves are generated.

Method, source array and source element that generate seismic waves. The source element includes an enclosure having an opening covered by a piston; a local supply accumulator fluidly communicating with an interior of the enclosure, a pressure of the fluid inside the local supply accumulator being larger than a pressure of the fluid inside the enclosure; a local supply valve located between the local supply accumulator and the enclosure and configured to control a flow of the fluid from the local supply accumulator to the interior of the enclosure; and a controller configured to control the local supply valve such that the pressure inside the enclosure does not fall below a first preset value based upon an ambient pressure of the enclosure while seismic waves are generated.

An assembly for providing an active seismic source includes a motor and a drive shaft coupled to the motor. A crank is coupled to the drive shaft. The motor is configured to impart rotation of the crank in a first rotational direction. A one-way bearing permits rotation of the crank relative to the drive shaft in the first rotational direction and inhibits rotation of the crank relative to the drive shaft in an opposed second rotational direction. The assembly also includes a strike plate, a track, and a hammer that is movable along the track along an axis that extends toward and away from the strike plate. The hammer contacts the strike plate. A biasing element biases the hammer toward the strike plate. A linkage arm couples the hammer to the crank and translates rotational movement of the crank to linear movement of the hammer.

An assembly for providing an active seismic source includes a motor and a drive shaft coupled to the motor. A crank is coupled to the drive shaft. The motor is configured to impart rotation of the crank in a first rotational direction. A one-way bearing permits rotation of the crank relative to the drive shaft in the first rotational direction and inhibits rotation of the crank relative to the drive shaft in an opposed second rotational direction. The assembly also includes a strike plate, a track, and a hammer that is movable along the track along an axis that extends toward and away from the strike plate. The hammer contacts the strike plate. A biasing element biases the hammer toward the strike plate. A linkage arm couples the hammer to the crank and translates rotational movement of the crank to linear movement of the hammer.