subsets. Highly significant differences between depth zone populations were found for both corallite diameters and growth rates in analyses of individual and combined reef data sets. Canonical variates analyses (CVA) separated populations from depth zones along single, highly significant, functions. Centroids and 95% confidence intervals, calculated from CVA scores of colonies in each population, are widely separated for the lagoon reef and combined data sets. Conversely, populations from shallow and intermediate depths on the outer reef display overlapping confidence bars indicative of more gradational morphologic changes. When CVv’s were used to classify specimens to groups, misassignments of intermediate depth specimens to shallow or deep-water populations underscored the gradational nature of the environment. Completely intergrading populations of Favia pallida collected from different depths can be morphologically separated into statistically distinct groupings. A stratigraphic succession of such morphotypes might be interpreted as abruptly appearing separate species if sampling were not as uniform, systematic, and detailed as was possible on modern reefs. Analyses of evolutionary patterns must carefully assess potential effects of clinal variation if past evolutionary patterns are to be interpreted correctly. Major Descriptors: *COASTAL REGIONS -- GEOMORPHOLOGY; *CORALS -- MORPHOLOGY 7 *ENIWETOK -- COASTAL REGIONS Descriptors: CLASSIFICATION; CLIMATES; CORRELATIONS; DEPTH; ENVIRONMENTAL EFFECTS; GEOLOGIC HISTORY; QUATERNARY PERIOD; REEFS; SAMPLING; STRATIGRAPHY; VARIATIONS Broader Terms: ANIMALS; CENOZOIC ERA; CNIDARIA; COELENTERATA; DIMENSIONS; GEOLOGIC AGES; GEOLOGIC STRUCTURES; GEOLOGY; INVERTEBRATES; ISLANDS; MARSHALL ISLANDS; MICRONESIA; OCEANIA Subject Categories: 10/5/345 580000* (Item 45 from file: 03183056 EDB-91-110492 Author(s): Henry, Title: -- Geosciences Introduction: 103) Enewetak Atoll and the PEACE program T.W.; Wardlaw, B.R. (Pacific Enewetak Atoll Crater Exploration) Source: United States Geological Survey, Professional Paper (USA) v 1513-A. Coden: XGPPA Publication Date: 1990 p Al-A29 Document Type: Journal Article Language: In English Journal Announcement: EDB9117 Subfile: ETD (Energy Technology Data Exchange). JMT (DOE contractor) US DOE Project/NonDOE Project: NP Country of Origin: United States Country of Publication: United States Abstract: An extensive study was made from June 1984 through August 1985 of the surface and subsurface configurations of two large nuclear craters on the northern side of Enewetak Atoll, Republic of the Marshall Islands. These craters, KOA and OAK, resulted from the near-surface 3681 detonation of two high-yield thermonuclear devices in 1958, when the atoll was part of the Pacific Proving Grounds. This multidisciplinary study was designed to produce a broad well-documented geologic, geophysical, and materials-properties data base for use in answering critical questions concerning craters formed by high-yield bursts. The study was part of a larger research initiative by the US Department of Defense to better understand high-yield, strategic-scale nuclear bursts Cc and how Pacific Proving Grounds craters relate to the basing and co targeting of nuclear-weapon systems and related national defense Lm issues. The data gathered during the study of the Enewetak craters are applicable to many scientific topics well beyond cratering mechanics and other related strategic concerns of the US DOD. These scientific topics include the geologic evolution of the Pacific Basin, the biologic and geologic history of a coral atoll, the fluctuation of sea level in response to glaciation and deglaciation, the diagenetic history of carbonate rocks in relation to sea-level changes and the