for National Geographic News
Hurricane Ivan, which struck U.S. shores September 15, 2004, kicked up the tallest, most extreme waves ever measured, scientists announced today.
At more than 90 feet (27 meters) tall from crest to trough and 600 feet (183 meters) long, the massive waves would "wipe out" a commercial fishing boat, said Douglas Mitchell. Mitchell is an oceanographer with the U.S. Naval Research Laboratory at the Stennis Space Center in Mississippi.
The researchers estimated the wave heights using water pressure data from undersea sensors that had been placed in the Gulf of Mexico for a separate project.
"Have you seen The Perfect Storm?" Mitchell said when asked to describe the extreme waves.
The reference is to the Hollywood movie based on Sebastian Junger's best-selling book about an October 1991 storm in the Atlantic Ocean. In the movie, waves the size of ten-story buildings swamp a 70-foot long-liner (a type of fishing boat) and its six-person crew.
Mitchell and Naval Research Laboratory colleagues David Wang, William Teague, Ewa Jarosz, and Mark Hulbert report their findings in tomorrow's issue of the journal Science.
The tallest measured wave was 91 feet (28 meters). The researchers believe they likely missed even larger waves because their sensors shut down before the most powerful region of the storm passed over them.
"If we had been fortunate enough to sample the waves when peak winds were overhead, we'd expect to have seen waves in excess of 130 feet [40 meters] from crest to trough," team member William Teague said.
At its peak intensity, the hurricane was a Category Five stormthe most powerfulwith sustained winds of 161 miles an hour (259 kilometers an hour).
Hurricane Ivan tore a deadly path across the Caribbean and Gulf of Mexico in 2004. It struck the Gulf Coast on September 15 with 130 mile an hour (209 kilometer an hour) winds and was directly resposible for 92 deaths. But the extreme waves disintegrated in the choppy waters of the Gulf of Mexico, never making landfall.
The Naval Research Laboratory team obtained their wave measurements when Ivan passed directly over a series of six concrete-ringed instrument packages deployed on the ocean floor about 75 miles (121 kilometers) south of Gulfport, Mississippi.
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