The hoa of Hull atoll and the problem of hoa

Abstract

This paper describes the channels known as hoa which are characteristic of atoll land rims and of some islands on barrier reefs, where they often dissect previously more continuous reef-top sediment accumulations and conglomerate platforms. They are especially common in the central Pacific, and are particularly well developed in some atolls of the Tuamotu Archipelago and on some of the Society Islands. Published hypotheses accounting for the origin and development of hoa of different kinds are outlined. Contemporary hoa on the north side of Hull Atoll in the Phoenix Islands are described and surveyed, as are older, probably Holocene hoa, here termed 'paleohoa', on the same atoll. Regional and local distributions of hoa and paleohoa and differences in hoa morphology are used to assess theories of hoa formation. Both hoa and paleohoa are attributed to hurricane activity, and the presence of paleohoa may thus give an indication of the distribution of hurricanes in the Holocene.