Hurricane Modification of the Offshore Bar of Long Island, New York

Abstract

N account of the New England hurricane of September 21, N 1938, and some of its effects has already been given in the Geographical Review.' It is the purpose of the present paper to report on a further aspect of the storm-the havoc wrought on the slender thread of sand constituting the offshore bar of southern Long Island. The damage to the bar was caused by huge storm waves striking from the crest of a swollen tide. Great gaps were opened in the bar, the high-water shore line was driven scores of feet inland, and acres of protective dunes were washed away. Many thousands of dollars have already been spent in reclamation work, and far larger sums will be involved if the comprehensive program of reconstruction now under consideration is adopted. The essential features of the proposed scheme are summarized on a later page. The present report not only describes the damage but attempts to analyze the processes involved. The post-hurricane modification of the bar, both natural and artificial, is considered, and the efficacy of the methods of artificial reclamation is examined. The changes effected in the bar may be summarized as follows: (1) formation of new inlets; (2) destruction of sand dunes; (3) development of shore-line irregularities; and (4) aggradation of the bar behind the dune line. In addition, the modification of the bar has so disturbed tidal conditions in the bays behind it that some areas formerly beyond the reach of even the highest tides are now periodically flooded.