A Numerical Model of Tides in the Cretaceous Seaway of North America

Abstract

A numerical model of the tides in an idealized Cretaceous Seaway of North America is used to calculate the lunar semidiurnal tide for a variety of possible values of controlling parameters. The most important parameters are the bathymetry and boundary conditions. Since the bathymetry of the Seaway is not well known, it suffices to use uniform-depth models. Separate runs are made for depths of 100, 200, and 600 m in a completely closed basin. The largest response is for the 200 m depth, because of a resonance of the Seaway at 211 m. Five additional runs are made for a depth of 200 m and different combinations of tidal forcing, according as the tidal force acts directly on the Seaway (independent tide) or indirectly through the Seaway's possible connection with the Arctic Ocean or Gulf of Mexico (co-oscillating tides). It is found that the independent tide accounts for the majority of the response of the Seaway. This is the opposite of modern marginal seas where the co-oscillating tide predominates. The co-...