Abstract
Seismic-acoustic properties of virtual (continuous spectrum) modes in an elastic waveguide are examined. Experimental observations made in a shallow water location in the Canadian Arctic Archipelago, where bottom compressional speeds are in excess of 4.5 km/sec, indicate that significant amounts of low frequency energy (lt;50 Hz) propagate with high speed to long range. The characteristics of this high speed energy are such that propagation occurs at preferred frequencies which can be associated with normal mode cutoffs. Moreover, there is a specific depth dependence of the energy in the water column at each frequency despite a high degree of time dispersion. Numerical results have been obtained using both a fast field program (FFP) technique and a normal mode approach applied to a layered elastic waveguide model of the location. The results are consistent with the experimental data and help define this unusual feature of shallow water propagation.
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© 1986 Plenum Press, New York
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Brooke, G.H., Thomson, D.J., MacKinnon, R.F. (1986). Some Characteristics of Virtual Modes in Shallow Water with High Speed Bottom. In: Akal, T., Berkson, J.M. (eds) Ocean Seismo-Acoustics. NATO Conference Series, vol 16. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-2201-6_24
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DOI: https://doi.org/10.1007/978-1-4613-2201-6_24
Publisher Name: Springer, Boston, MA
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