Complex Morpho-Hydrodynamic Response of Estuaries and Bays to Winter Storms: North-Central Gulf of Mexico, USA

Concepts pertaining to our understanding of estuarine dynamics have been heavily influenced by work carried out on the east and west coasts of the United States and western Europe (Pritchard, 1967). Antecedent geological controls have played an important role in predetermining the dominant type of estuaries along these coasts, namely drowned river valleys on coastal plains and fjord type systems tuned to moderate/high tidal regimes. Along the northern Gulf of Mexico (Fig. 1), however, estuaries are predominantly bar-built where the latest Holocene “stillstand” in sea level has permitted waves to build barrier islands/spits/beaches supplied by sediment from updrift and offshore sand sources (Stone et al., 1992; Stapor and Stone, 2004). Tides in the Gulf of Mexico are microtidal (0–0.3 m), predominantly diurnal and mixed (Marmer, 1954). Characteristically broad regions of low bathymetric relief result in minimal bathymetric steering of the otherwise low-frequency flow (Schroeder and Wiseman, 1999). Due to a high incidence of tropical cyclones in the northern Gulf (Stone et al., 1997; Muller and Stone, 2001), low profile barriers are susceptible to multiple breaches and inlet development. Such occurrences play an important role in estuarine circulation patterns due to phase lags in tidally driven waves. These interlinkages have, however, yet to be fully explored (Schroeder and Wiseman, 1999).