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for quantifying the erosion impact, has been validated by 

 field tests on the Great Lakes. £/ The shore maintains the 

 equilibrium profile shown by the solid line. When sea level 

 rises, this profile must also rise, which requires additional 

 sediment equal to bj_. Unless sediment is transported into the 

 area by currents or by mechanical dredges, ocean waves will 

 provide the sediment by eroding enough sand from the upper 

 portion of the beach to equal b, producing the new profile 

 shown by the dotted line. Applications of this theory have 

 concluded that a rise in sea level of one centimeter can cause 

 the shore to erode between one hundred and one thousand 

 centimeters on the Atlantic and Gulf coasts of the United States, 



FIGURE 5-1 

 BRUUN RULE 



BEACH 



INITIAL SEA LEVEL 



BOTTOM PROFILE/ 

 AFTER SEA 



LEVEL RISE 



a = a 

 b — b 



LIMITING DEPTH 

 BETWEEN PREDOMINANT 

 NEARSHORE AND 

 OFFSHORE MATERIAL 



SHORE EROSION FOLLOWING A RISE IN SEA LEVEL ACCORDING TO 

 THE BRUNN RULE (AFTER SCHWARTZ 1967) "THE BRUNN THEORY OF 

 SEA LEVEL RISE AS A CAUSE OF SHORE EROSION, " ADOPTED FROM 

 THE JOURNAL OF GEOLOGY, 75, 76-92. 



