Meteotsunami Animation: U.S. East Coast, June 2013

PTWC scientists used their tsunami forecast model, RIFT, to simulate how a weather-generated tsunami, or meteotsunami, may have propagated off of the east coast of the United States in the north Atlantic Ocean on June 13, 2013. A "derecho," or a rapidly-moving coherent storm front, traveled eastward across the US's mid-Atlantic states and out over the ocean as an atmospheric pressure anomaly. It appears in the animation as a prominent "negative" wave or trough in the sea's surface. It generates meteotsunami waves as it moves, and when it reaches the edge of the continental shelf (seen as a change from light blue to darker blue colors in the ocean) the waves jump or "spike" in amplitude there and propagate along the shelf's edge. The meteotsunami waves reflect landward from the shelf's edge due to the rapid change in wave velocity there (tsunami waves travel much faster in deeper water), then reflect again seaward from the coastline. Thus these waves become trapped in the shallow water of the continental shelf and oscillate back-and-forth for hours. If you watch carefully you can also see the polarity of the waves change when they reflect such that violet waves turn green and vice-versa. Some wave energy also escapes to deeper water where they travel much faster and with longer wavelengths. As the animation approaches 12 hours of simulated time it transition to an "energy map" showing the maximum meteotsunami wave heights for this region, then concludes with a forecast of maximum calculated values of wave heights at the coastlines. This animation will be part of Wang et al.'s presentation on this topic at the 2013 American Geophysical Union Fall Meeting: http://fallmeeting.agu.org/2013/