debris or even be radioactive because of the activating effects of the device's neutron output. OCEANIC TESTING OPERATIONS The implications of oceanic testing have only incidentally been remarked upon. These are now discussed, especially as they relate to DOD operations during CASTLE. Marshall Islands Setting The Marshall Islands are in the easternmost part of the area known as Micronesia (“tiny islands"). (2 million km*) The Marshalls cover about 770 thousand mi? of the Earth's surface but the total land area is only about 70 mi (180 km?) . Two parallel chains form the islands: Ratak (or Sunrise) to the east, and Ralik (or Sunset) to the west; both Enewetak and Bikini are in the Ralik chain at its northern extreme. Figure 1 shows these islands in the Central Pacific, Figure 2 is a map of Enewetak Atoll, and Figure 3 is a map of Bikini Atoll. Typical atolls, Enewetak and Bikini are coral caps set on truncated, submerged volcanic peaks that rise to considerable heights from the ocean floor. Coral and sand have gradually built up narrow islands into a ring- like formation with open ocean on the outside and a relatively sheltered lagoon on the inside. Both atolls have two passages, a wide passage and a deep one, that permit access to their lagoons from the sea. has a thifd. Enewetak also All the islands are low-lying, with elevations seldom over 20 feet (6 meters) above high tide. During nuclear testing, the more populated, support~-oriented sections were the south and southeast areas of the atoll where the larger islands exist. Devices were detonated on the northern islands and over the north- ern reefs. The western sections of the atoll were not involved in test activities except for limited use as instrumentation sites. Elliptically shaped, Enewetak is approximately 550 nmi southwest of Wake Island and 2,380 nmi 37 (4,410 km) (1,020 km) southwest of Honolulu.