January 25, 2010    Maximum height of extreme waves up dramatically in Pacific Northwest

Wave heights are increasing off the Pacific Northwest, according to a new study at Oregon State University and the Oregon Department of Geology and Mineral Industries. (Photo by Erica Harris, Oregon State University)

A major increase in maximum ocean wave heights off the Pacific Northwest in recent decades has forced scientists to re-evaluate how high a "100-year event" might be, and the new findings raise special concerns for flooding, coastal erosion and structural damage.


The new assessment concludes that the highest waves may be as much as 46 feet, up from estimates of only 33 feet that were made as recently as 1996, and a 40 percent increase. December and January are the months such waves are most likely to occur, although summer waves are also significantly higher.

In a study just published online in the journal Coastal Engineering, scientists from Oregon State University and the Oregon Department of Geology and Mineral Industries report that the cause of these dramatically higher waves is not completely certain, but "likely due to Earth's changing climate."

Using more sophisticated techniques that account for the "non-stationarity" in the wave height record, researchers say the 100-year wave height could actually exceed 55 feet, with impacts that would dwarf those expected from sea level rise in coming decades. Increased coastal erosion, flooding, damage to ocean or coastal structures and changing shorelines are all possible, scientists say.

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Dear gawd...can you actually imagine a wave fifty-five feet high measured from sea level to crest?   One that just keeps going up and up and up....a solid wall of water?   The very concept makes me nervous.

A