ek eek es a ada es: (1) The four principal zones. nels com- terrace. ef of one (2) At These are The Algal Ridge does not rise to a well defined crest; instead The zone is about 200 feet wide. maximum of 1 foot above low tide level. *y¥ probably The Reef Flat, which at low tide is covered with about 1 foot of water, f the zone (3) is a floor of algal limestone, irregular and hummocky with sandy patches in the l1x inches hollows. 910 feet This zone is about 50 feet wide. about 30 feet wide, essions, (4) The Beach Rock Zone, which is consists of a rough rock platform on which lie boulders and the bedded sandstone of the islet shore. ard with The lagoon beach side of KEITH is composed of a sharply sloping and narrow sand beach which extends down to about 2ple-marked low water level and there meets a flat of coral limestone which gradually slopes -omeg downward as one proceéds toward deeper lagoon water. The lagoon Heavy vegetation on KEITH is located principally on its northwestern half. am ebSS ng ward and 1 edge i oetciE mN, *astward about 0.3 by south- A heavy stand of mature coconut trees dominates this area. The southeastern half of the islet supports only secondary brush-type vegetation, principally Scaevola. (See Section 6.) MACK is an artificial site built upon a very large coral head which is located in the northeastern quadrant of the lagoon. MACK is approximately 7 miles due west of YVONNE and § miles due south of JANET. instal- This site consists of a large platform some 10 feet above sea level upon which has been built a steel L topo- tower some 45 feet in height (Figure 12). narrow REllea meee ae ONSIE i bile ee this There are no exposed land areas at site, 6. VEGETATION Eniwetok Atoll is considered on the basis of the vegetation to be one of the drier of the Marshall Islands. as Polypodium and Asplenium, on many of the other atolls. rea This is evidenced by the lack of ferns such and of shrubs such as Pipturus, which are present The paucity of bryophytes and foliose lichens above a4 meter or a meter and a half above the ground is further indication of the BeeAs abc 1 into a there are scattered hummocks or mounds about 20 to 60 feet across that rise to a numeroug t nearly ad about 30 feet deep at the reef edge and continue seaward to the edge of the ‘one is about -€3 near okt ice ee separated by wide deep canyon-like channels which extend far down below sea level. 3 are floored 211). dean The Terrace slopes seaward for some 100 to 300 feet, its outer edge 1t consists of irregular lobate algal spurs, °ts of the land Eat where at an apparent depth of 10 or 15 fathoms it drops off quite steeply. 3 & whole ig bove 13 (1) ddl Ma he comparative dryness. 15 TOcet te ee eR rene a Re ERS eee 2ReNEI mee es oe ee <tr ARAN Ae a ame " me egetAE ,