A new study suggests giant waves generated by hurricanes occur more frequently than originally thought. Unlike tsunamis, which start at the ocean floor, these waves are created by a hurricane's winds on the sea surface.
As most ships avoid hurricanes, instruments on the ocean floor that measure water pressure were used to calculate the findings. Scientists at the Naval Research Laboratory at Stennis Space Center in Mississippi used readings from those instruments to calculate the height of waves from trough to crest.
The study is being published today in the journal Science.
According to those instruments, Hurricane Ivan generated 146 large waves off the Mississippi coast last September, including one wave that reached 91 feet. The giant wave did not reach shore.
Scientists at the National Oceanic and Atmospheric Administration use buoys at sea to calculate wave heights. An ocean wave expert at the NOAA's Climate Prediction Center says a wave such as the giant one measured during Ivan is within expected limits.