While wave watching is a favorite pastime of beachgoers, few
notice what is happening in the shallowest water. A closer look by two
University of Colorado Boulder applied mathematicians has led to the discovery
of interacting X- and Y-shaped ocean waves that may help explain why some
tsunamis are able to wreak so much havoc.
Professor Mark Ablowitz and doctoral student Douglas Baldwin
repeatedly observed such wave interactions in ankle-deep water at both Nuevo
Vallarta, Mexico, and Venice Beach, Calif., in the Pacific Ocean --
interactions that were thought to be very rare but which actually happen every
day near low tide. There they saw single, straight waves interacting with each
other to form X- and Y-shaped waves as well as more complex wave structures,
all predicted by mathematical equations, said Ablowitz.