The cry goes up — "Save the Hatteras 

 Light!" — and thousands rally to help, while the 

 lighthouse itself stands resolute, brave as a ban- 

 ner. 



But while we battle the sea for inches on one 

 hand, it steals yards on another. Houses topple, 

 walls collapse. The sea keeps coming. State of- 

 ficials go about the often unpopular job of plan- 

 ning an orderly retreat. And the geologists are 

 saying — to paraphrase Pogo — the enemy is us. 



This month, Coastwatch looks at the problem 

 of beach erosion, and what can be done about it. 



Photo by Steve Wilson 



What's eating at North Carolina beaches? 



The word itself is a part of the 

 problem. Erosion. Inland, it means 

 gullied banks, silted streams and air- 

 borne topsoil. Erosion, we've been 

 taught, is something man provokes 

 when he disturbs the earth, and 

 something he can stop — with walls, 

 plants or more prudent farming. 



But the sea erodes an ocean beach 

 whether man is there or not, and 

 geologists say that, while we might 

 temporarily divert beach erosion from 

 one place to another, there is nothing 

 we can do to stop it. 



As long as sea level continues to rise, 

 our barrier island beaches will recede, 

 and the islands themselves will 

 "migrate" landward. 



Photo by Neil Caudle 



"Things out here aren't like inland 

 areas," says Spencer Rogers, Sea 

 Grant's coastal engineering specialist. 

 A few hundred feet outside his office at 

 the N. C. Marine Resources Center at 

 Ft. Fisher, the sea is marching steadily 

 landward. 



"Geology is an active, real process 

 out here on the beach," Rogers con- 

 tinues. "You can leave your lot in 

 Raleigh on the day you're born, come 

 back to it in seventy years, and there 

 will be practically no change in the 

 shape of the lot. If you have a lot on 

 the beach that long, it's going to 

 change dramatically. It may disappear 

 altogether." 



Most of North Carolina's 320 miles 



"You can leave your 

 lot in Raleigh on the 

 day you're born, come 

 back to it in seventy 

 years, and there will be 

 practically no change 

 in the shape of the lot. 

 If you have a lot on the 

 beach that long, it's 

 going to change 

 dramatically. It may 

 disappear altogether." 

 — Spencer Rogers 



of island beaches are backing up. Some 

 48 percent of the shoreline has been 

 eroding at a rate greater than two feet 

 each year. Eighteen percent of the 

 coastline has been disappearing at an 

 annual rate of more than six feet a 

 year. 



But about 54 miles of North 

 Carolina beaches are actually gaining 

 ground, "accreting." Some of this ac- 

 cretion happens when a beach collects 

 sand lost from the opposite shore of a 

 shifting inlet. Other beaches are ac- 

 creting or eroding only very slowly be- 

 cause they face south, which gives 

 them some shelter from the severe 

 storms called northeasters, or because 

 they are positioned in such a way that 

 they catch sand lost from nearby 

 capes. 



This landward march is not as or- 

 derly and predictable as mere statistics 

 make it seem. Areas such as North 

 Rodanthe and Pea Island in Dare 

 County, and Seagull in Currituck 

 County, are eroding at mysteriously 

 high rates. And, when it comes to a 

 major storm or hurricane, no one can 

 predict with confidence the reach of 

 erosion. 



"Geology responds to the high- 

 energy storm events," says Stan Riggs, 

 an East Carolina University geologist 

 and Sea Grant researcher. "The energy 

 expended day-to-day is not much com- 

 pared to what is released in a 

 catastrophic storm." 



Riggs and Rogers explain that while 

 the record may show a certain beach 

 eroding two feet a year on average, a 

 single storm might bring thirty years' 



