182 E. C. ANDREWS. 



The action of storms has also been to pile up another 

 series of great bay bars off-shore of the present Lady 

 Robinson's Beach following upon the emergence of the old 

 bars from the waves. 



There still remains the question of origin of the beach 

 cusp or scallop which has received attention from geo- 

 graphers and geologists at various times. 



The storm beach associated with shallow offshore areas 

 may be described as a high flat beach of fairly even slope. 

 It is cuspless ; it is considerably built up near low water 

 mark as compared with the beach of normal weather, and 

 it is considerably cut down at, and landward of, ordinary 

 high tide mark. The aim of the giant wave is to demolish 

 the solid land, and in endeavouring to carry out its purpose, 

 it builds up a great sand (or pebble) bridge of gentle slope 

 from breaker line to its point of attack so as to minimise its 

 work. The beach in fact is an inclined plane, whose angle 

 of inclination is lowered in proportion to the increase in 

 strength of the wave, and when beach and wave strength 

 are in adjustment the former must be regular and fairly 

 even or smooth because friction has been reduced to a 

 minimum. At the seaward edge of this beach the heavy 

 waves break, and reforming, they advance in continually 

 foaming stage except for the periodic heavy rollers which 

 rush up the beach. Such waves do not appear to have 

 indented fronts, at least not as observed on Lady Robinson's 

 Beach during the storm of July 1912. 



Upon the decrease of wave strength such diminished 

 wave finds the storm beach slope ill adjusted to its strength, 

 and straightway it proceeds to adjust the beach profile to 

 its strength. Its wave base 1 is not so far below the sea 

 surface as that of the storm wave. It accordingly breaks 



1 Depth below water surface at which waves can effectively agitate 

 sediments. 



