Breaking Waves pp 367-373 | Cite as

Observations of Shock and Undular Bore Formation in Internal at a Shelf Break

  • P. E. Holloway
Conference paper
Part of the International Union of Theoretical and Applied Mechanics book series (IUTAM)


Large amplitude internal waves at semi-diurnal tidal frequency (internal tides) are observed to be generated over the slope region of the Australian North West Shelf and propagate shoreward over shoaling bathymetry. In deep water the waves are nearly linear in shape and are seen to steepen and become strongly non-linear as they propagate. The waves steepen at the leading edge to the point where an internal hydraulic jump or shock forms. The shocks are generally downwards and are weak shocks seen as undular bores. At times a second, and weaker, backward shock forms on the trailing edge of the wave. The undular bores are followed by a train of oscillations that can be reasonably described as solitons. An analytical model using a perturbed extended Korteweg-de Vries equation is used to describe the evolution of an initially sinusoidal wave as it progagates over an exponential depth profile, in the presence of a background current of constant shear, and breaks to form a shock. The model predictions, of the distance the wave propagates before forming a shock, and of the height of the shock as it propagates, compare well with observations.


Internal Wave Internal Tide Shelf Break Shock Strength Buoyancy Frequency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1992

Authors and Affiliations

  • P. E. Holloway
    • 1
    • 2
  1. 1.Department of Geography and OceanographyUniversity College, University of New South WalesAustralia
  2. 2.Australian Defence Force AcademyCanberraAustralia

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