Alternative source for marine geophysical exploration

Authors

  • Paul Yeatman Geospectrum Technologies Inc., 10 Akerley Boulevard, Dartmouth, NS B3B 1J4, Canada
  • Sara Stout-Grandy GeoSpectrum Technologies Inc., 10 Akerley Boulevard, Dartmouth, NS B3B 1J4 L-J, Canada
  • Bruce Armstrong GeoSpectrum Technologies Inc., 10 Akerley Boulevard, Dartmouth, NS B3B 1J4 L-J, Canada

Keywords:

Geophysical prospecting, Air guns, Alternative source, Free fields, Fundamental physics, Geophysical exploration, Higher frequencies, Large displacements, Low frequency, Lower frequencies, Mechanical stiffness, Operating frequency, Power levels, Surface reflections, Vibroseis, Water surface

Abstract

Fundamental physics issues associated with low frequency sources, particularly when they are operated near the water surface, and why it is so difficult to achieve even a small fraction of the power that an air gun produces with electroacoustic other marine vibroseis technologies, are discussed. The power level achieved at 5m depth is about the same as in the free field at 25Hz, but at lower frequency it is attenuated and at higher frequencies it is boosted by the surface reflection. Studies were conducted to find that low frequency projectors just either produce large displacements or have large radiating areas, or both. The operating frequency of a transducer greatly affects the transducer size and effectiveness. To reduce the operating frequency, transducer is made less stiff. In air backed transducers, such as flex-tensionals, the operating frequency is lowered by reducing the mechanical stiffness of the flexing member.

Additional Files

Published

2012-09-01

How to Cite

1.
Yeatman P, Stout-Grandy S, Armstrong B. Alternative source for marine geophysical exploration. Canadian Acoustics [Internet]. 2012 Sep. 1 [cited 2024 Sep. 16];40(3):88-9. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/2553

Issue

Vol. 40 No. 3 (2012)

Section

Proceedings of the Acoustics Week in Canada

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