Sea Coast Erosion

Dominion, Volume 29, Issue 256, 25 July 1936, Page 11

Sea Coast Erosion

Sir, —I have heard several suggestion* made to account for the serious erosion that is now taking'place at the beaches north of Paekakariki. One is that it is part of some regular cycle of accretion and erosion, with a periodicity not known. Another is that it is due to t> fresh set in the currents, caused by changes In the contours of the ocean-bed due to some recent submarine earthquake A third theory agrees that it is current-erosion, and that the sea-bed must hove altered, but suggests that this comes about by some movement in the earth’s ciust which ip accelerating so as to become noticeable. A fourth suggestion is that it is due rather to a lowering of the coastlevel along one of the fault-lines of the locality. If there is anything in the third, or fourth suggestion, Nature may be g’ving us a kindly warning which it would be foolish to disregard, and which the experts should be asked to interpret. It is rather against the last theory that the erosion is not uniform, as might oe expected with a sinking coast-line, but at intervals; it is of the nature of an eroding current to strike toward the bank at certain places, and at others- to swing away from it. Probably, however, the last theory is the only one capable of being verified or disproved. It would be of interest, therefore. to know whether any information is available about datum-levels in this vicinity.—l am, etc., BEACH-DWELLER.