NRL Measures Record Wave during Hurricane Ivan
August 4, 2005
Scientists at the Naval Research Laboratory—Stennis Space Center (NRL-SSC) measured a record-size ocean wave when the eye of Hurricane Ivan passed over NRL moorings deployed last May in the Gulf of Mexico. The possibility of a super wave is often suggested by anecdotal evidence such as damage caused by Hurricane Ivan in September of 2004 to an offshore rig in the Gulf of Mexico that was nearly 80 feet above the ocean surface. Hence, some of the destruction done by Ivan has been attributed to a rogue wave. According to industry and national weather sources, the damage done by waves during Ivan has been on the extreme high end for a category 4 hurricane.

During NRL’s Slope to Shelf Energetics and Exchange Dynamics (SEED) field experiment, six current profiler moorings that also contained wave/tide gauges (Sea-Bird Electronics SBE 26) were deployed on the continental shelf at water depths ranging between 60 and 90 meters (197-295 feet) just west of the DeSoto Canyon, about 100 miles south of Mobile Bay, Alabama. An additional eight deep moorings were deployed down the shelf slope but did not contain wave/tide gauges. Fortuitously, between 8:00 pm CDST and midnight on September 15, the eye of Ivan passed through the center of the array, and almost directly over moorings 2, 5, 8, and 11. Historically, instruments in the ocean do not even survive near misses of such powerful storms, much less direct hits. Fortunately, all of the SEED moorings survived this powerful storm, and provided the best ocean measurements of currents and waves ever obtained directly under a major hurricane.
During the approach of Ivan, a moored buoy (ID 42040), deployed by the National Data Buoy Center (NDBC) near the west side of the SEED array, registered a significant wave height of 16.0 meters (53 feet). Unfortunately, the NDBC buoy broke loose and was set adrift on September 15 at 5:00 pm CDST, just before the arrival of the main force of the hurricane. According to a spokesman at NDBC, this wave height appears to be the largest ever reported by NDBC from a hurricane and comes within a few tenths of a meter of NDBC’s all-time record reported in the North Pacific. Note that the wave heights reported by the NDBC buoys are derived from wave spectra.