Analyses of Hurricane Ivan wave in the Gulf of Mexico

The large waves caused by Hurricane Ivan have received considerable media coverage because of the extensive damage they wrought on the offshore oil industry and on the coastal areas of the Gulf of Mexico. It has been speculated that the associated wave conditions correspond to the 1000-year event and that criteria for designing offshore structures in the Gulf of Mexico may need revision. Here, we describe one analysis of all of the measurements from NDBC buoys in the Gulf of Mexico and elsewhere in US waters, with a view to placing Hurricane Ivan´s waves in the context of other measurements. The largest significant wave heights (SWH´s) measured during Hurricane Ivan in the Gulf of Mexico rival the largest waves ever recorded in all US waters. This is noteworthy because, on a return period basis, the Gulf of Mexico has the smallest wave climate compared with all other regions around the US. At four locations in the Gulf of Mexico, the SWH´s were the largest ever recorded at those locations, and exceeded the previous biggest waves by a significant margin. Wave-induced velocities are estimated to be as high as 3.5 m/s at some locations, which may have contributed to the extensive mud, sediment, and pipeline movements that have been reported. Calculations based on the admittedly short-duration datasets suggest that the some SWH´s measured during Hurricane Ivan may correspond to recurrence intervals of the order of several thousand years.