Ivan forced evacuation of 75 percent of the 574 manned platforms

The NRL-SPC directly measured 146 large waves, including 24 higher than 50 feet and one at 91 feet, when the eye of Hurricane Ivan passed over NRL moorings deployed last May in the Gulf of Mexico. Some of the destruction done by Ivan has been attributed to a rogue wave, researchers say.

Analysis of the wave data with the winds suggests the wave heights likely exceeded 130 feet near the eye wall of the hurricane, researchers said.

The Minerals Management Service reported Ivan forced evacuation of 75 percent of the 574 manned platforms in the Gulf and 59 percent of the 69 drilling rigs, set adrift five rigs and sunk seven rigs entirely.

Aside from obvious leaks, some pipelines were reported to have moved 3,000 feet while others were buried under 30 feet of mud and cannot be found. The findings are published in Science, Physorg.com reports.

The giant wave was detected 75 miles south of Gulfport, Miss., by instruments on the ocean floor that measure the pressure of water above them. Using those readings, scientists can calculate the height of waves from trough to crest, The Seattle Times reports.