Marine seismic vibrators and methods of use

An array of marine seismic vibrators comprising:

• one or more low frequency marine seismic vibrators, wherein the one or more low frequency marine seismic vibrators each comprise:
• a first shell having a spring constant selected to provide a first resonance frequency within a first operational frequency range of about 5 Hz and about 25 Hz, wherein the first shell comprises endbeams and shell side portions coupled to the endbeams, wherein a plurality of protruding ribs are disposed on either side of a midline of at least one of the shell side portions of the first shell, wherein the protruding ribs of the first shell force the corresponding shell side portions to bend at the midline;
• a first driver disposed within the shell and having a first end and a second end;
• and
• a first spring element coupled to the shell between the first end and the second end of the driver;
• wherein the spring element has a second mode of oscillation that provides a second resonance frequency within the first operational frequency range;
• and
• one or more high frequency marine seismic vibrators, wherein the one or more high frequency marine seismic vibrator each comprise:
• a second shell having a spring constant selected to provide a first resonance frequency within an second operational frequency range of about 25 Hz to about 100 Hz, wherein the second shell comprises endbeams and shell side portions coupled to the endbeams, wherein a plurality of protruding ribs are disposed on either side of a midline of at least one of the shell side portions of the second shell, wherein the protruding ribs of the second shell force the corresponding shell side portions to bend at the midline;
• a second driver disposed within the shell and having a first end and a second end;
• and
• a second spring element coupled to the shell between the first end and the second end of the driver;
• wherein the spring element has a second mode of oscillation that provides a second resonance frequency within the second operational frequency range.

A marine seismic vibrator comprising:

• a shell having a spring constant selected to provide a first resonance frequency within an operational frequency range of about 1 Hz and about 300 Hz, wherein the shell comprises beams disposed on either end of the shell and two shell side portions hingedly coupled to the beams;
• wherein the two shell side portion each comprise an outer surface and ribs that are spaced along the outer surface in columns on either side of a mid-line, wherein the ribs extend outwardly from the outer surface;
• a fixture disposed within the shell and coupled to the beams;
• a linear drive mounted on the fixture and having a first end and a second end;
• and
• a spring element coupled to the shell between the first end and the second end of the driver, wherein the spring element has a second mode of oscillation that provides a second resonance frequency within the operational frequency range.