An apparatus of confining an earth block to engage with a horizontal vibrator for generating shear dominated seismic source and a method of applying the apparatus are related. An apparatus of confining an earth block to be engaged with at least one vibrator for generating a shear dominated seismic source comprises a plurality of horizontal steels, a plurality of vertical steel sheet piles, a plurality of vertical elongated steel pile sheets, a plurality of horizontal elongated steels, and at least one vibrator.

Techniques are disclosed relating to the determination of a warping attribute related to a difference between an up-going pressure wavefield and a down-going pressure wavefield received from a seismic data acquisition system. The warping attribute is used to determine a pseudo up-going or down-going pressure wavefield. The pseudo pressure wavefield is used to generate a modified record of geophysical data, which is stored in a non-transitory memory medium as a geophysical data product.

A method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

A method for selecting parameters of a seismic source array comprising a plurality of source elements each having a notional source spectrum is described, the method comprising calculating a ghost response function of the array; calculating directivity effects of the array; and adjusting the parameters of the array such that the directivity effects of the array are compensated by the ghost response to minimize angular variation of a far field response in a predetermined frequency range. A method for determining a phase center of a seismic source array is also related, the method comprising calculating a far field spectrum of the array at predetermined spherical angles, and minimizing the phase difference between the farfield spectra within a predetermined frequency range by adjusting a vertical reference position from which the spherical angles are defined.

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.