Wind AND 



TAKE A BITE 



The Bible warns people not to build a house upon 

 the sand. 



The seventh chapter of Matthew reads: "The rains 

 came down, the floods rose, the winds blew and beat 

 upon that house and it collapsed. And the wreck of it 

 was complete." 



But people ignore this advice. 



Lured by the beauty of the sea and the beach, people 

 perch their houses and hotels near the ocean's sandy 

 edge. 



But on the first of January 1987 the rains did come, 

 the ocean did rise and the winds did blow. 



These forces beat upon the houses of coastal North 

 Carolina. And one Long Beach residence collapsed; it 

 was a complete wreck. 



The Jan. 1 northeaster was a harsh reminder of this 



biblical parable. At Long, Kure, Carolina and Topsail 

 beaches, the northeaster's lashing waves licked up vast 

 quantities of beach sand, undermined the foundations 

 of some houses and tore away the stairways, dune 

 walks, porches and ground-floor walls of other ocean- 

 front dwellings. 



It was erosion at its worst. 



Winter northeasters are notorious for hurling their 

 erosive forces at the North Carolina coast. In fact, in 

 recent years these storms have been more destructive 

 than hurricanes, says Sea Grant researcher John 

 Fisher, a civil engineer at N.C. State University. 



As part of the Sea Grant research project. Fisher and 

 another NCSU civil engineer, Margery Overton, are 

 studying the effects of winter storms on dunes. 



When the study is complete, the team will be able to 

 plug information about a dune's size and a storm's in- 

 tensity into a computer model and estimate the amount 

 of dune erosion expected from a storm. 



Fisher says dune erosion is based on several 

 factors— the height of the tide, the magnitude of the 

 waves, the size of the dune and the amount of dune 

 vegetation. 



The New Year's Day northeaster arrived on an 

 astronomical high tide. The sun, moon and earth were 

 aligned so that their gravitational effects combined to 

 produce higher high tides and lower low tides. 



Combine these high tides with a northeaster's strong 

 onshore winds, which often clock in at 50 mph or 

 more, and you get an eroding combination. 



"Big winds make big waves, and big waves destroy 

 dunes," Fisher says. 



Erosion occurs as nature tries to strike a balance be- 

 tween water elevation, wave action and sand size, says 

 Spencer Rogers, Sea Grant's coastal engineer. 



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