Measuring Monster Waves

By Keith Randall

Imagine standing on board a ship, looking straight up and seeing a wave as tall as a 10-story building about to crash on top of you.

If you were a ship captain and there might be 90-foot waves headed your way, you’d appreciate some information about them, right?

That’s the idea behind a wave model system that a Texas A&M University at Galveston professor has developed. His detailed wave prediction system is currently in use in the Gulf of Mexico and the Gulf of Maine.

Vijay Panchang, head of the Department of Maritime Systems Engineering, doesn’t make waves — he predicts what they’ll do, when they’ll do it and how high they’ll get.

Using data provided daily from the National Oceanic and Atmospheric Administration and his own complex mathematical models, Panchang and research engineer Doncheng Li provide daily wave model predictions for much of the Texas coast, the Gulf of Mexico and the Gulf of Maine. Their simulations, updated every 12 hours, provide a forecast for two days ahead.

“The models we provide are based on very detailed information, such as seabed topography, offshore wave conditions, wind speed and direction, and other factors,” Panchang explains.

“The models provide useful information for anyone in coastal waters. Texas has a huge coastline, and Maine has more than 3,000 miles of coast. Recreational and fishing boats, cruise ships, commercial ships and others can use this information. Coastal wave information can also be used to predict sediment transport and for engineering design.”

The models use wind data and thus can’t predict tsunamis, which are created by undersea earthquakes. But that’s not to say his modeling system doesn’t come up with some big waves.

His wave model predicted big waves in November 2003 in the Gulf of Maine, and it was accurate — waves as high as 30 feet were recorded even in coastal regions during one storm.

In 2004 during Hurricane Ivan, a buoy located 60 miles south of the Alabama coast recorded a whopping 60-foot wave. “There may have been higher waves because right after recording the 60-foot wave, the buoy snapped and stopped functioning,” he says.

“Also, the 50-foot wave is an average measure of the sea state, and the highest waves could be nearly twice as big. Waves during storms can be quite high, and 50-foot waves are not uncommon,” Panchang reports.

He notes that during a storm in 1995 off the Halifax coast, the captain of the Queen Elizabeth II reported a monstrous 95-foot wave.

He thought that the record-breaking hurricane season of 2005 would provide similar wave records, but no such luck. Panchang was hoping to get valuable information about wave heights from Hurricanes Katrina and Rita, two of the deadliest storms on record. Rita did extreme damage along the Texas–Louisiana coast, whereas Katrina virtually wiped out New Orleans.

Both storms were so severe that they damaged the buoys and recording devices he uses for wave modeling. But in July, he did record waves at least 60 feet high during Hurricane Dennis.

Panchang is also developing a similar wave model prediction system for the Prince William Sound Oil Recovery Institute in the Alaska port of Valdez, site of the Exxon Valdez oil spill. That wave model system should be online by next year.

“Anyone on the water wants to know how high the waves will be when they are out at sea,” he says. “We provide a valuable service to those on ships and boats who want to know what the wave conditions will be like in the next 24 hours.”

NOAA Sea Grant, the Texas Coastal Management Program, the Prince William Sound Oil Spill Recovery Institute and the National Marine Fisheries Service provide funding for Panchang’s wave model prediction system.