Kerry K. Kuehn

Fluid dynamics and the Tides of Fundy

In June, my family and I visited the Bay of Fundy, which is situated between New Brunswick and Nova Scotia. The Bay of Fundy is famous for its unparalleled tidal ranges—which can reach up to 70 feet from low to high tide—and its stunning rock formations. Some still images taken at Hopewell Rocks and Fundy National Park can be seen here.

The following movie clips are from the Saint John river in New Brunswick, where the rising tide in the Bay of Fundy causes the river to reverse twice each day. The resulting fluid flows are rich and fascinating. In the first clip, one can see vortices forming as the salt water from the Bay rushes past the counter flowing fresh water from upstream (shearing flow and Kelvin-Helmholtz instability). In the second clip, one can observe buoyancy-driven flow as plumes of low-density fresh water rise through the in-flowing saltwater (Rayleigh-Taylor instability).