REEFS OF BIKINI, MARSHALL ISLANDS
Systematic surveys made at Bikini before and after the atomi bomb tests (Operation Crossroads) in the summer of 1946 afforded an unusual opportunity to examine the reefs and islands of one of the larger atolls of Micronesia. The existing reef appears to be developed on an older surface that extends as a terrace into the lagoon and beyond the seaward margin of the reef. A sketch map shows the distribution of the terraces in relation to the existing reefs.

Reef zonation is briefly described, and a classification of reef types based upon the characteristics of the marginal zone is presented. Illustrations are given from Bikini's reefs and those of near-by atolls. A sketch map shows the distribution of the reef types at Bikini relative to prevailing winds and currents. The processes of reef growth and unusual areas wherein the existing reef appears to be undergoing destruction are also described and figured.