4
RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL
Description and History: 1526-1972
assigned female namesin alphabetical order beginning with ‘Alice’ and
continuing clockwise through ‘‘Yvonne.’’ The southern islands were
wee
ee nn ne
assigned male names beginning with ‘‘Alvin’’ and continuing clockwise
through ‘‘Leroy.’’ Subsequently, additional sité names were assigned to
smailer islands and other features, disrupting the original order of
assignment. The site names are shownin parentheses in Figure I-4. The
spelling used for the island namesis that adopted in 1974 by the U.S. Board
of Geographical Namesas best representing the pronunciations of the driEnewetak.
The atoll is approximately 23 by 17 statute miles with the long axis
running northwest to southeast. The land surfaceareatotals 1,761 acres or
2-3/4 square miles (Figure 1-5). The lagoon has an area of approximately
388 square miles. Its depth averages 160 feet with a maximum of
approximately 200 feet.2:3 There are three entrances to the lagoon: the
east channel or Deep Entrance, [80 feet deep, lving between Medren
(Elmer) and Japtan (David); the Wide Passage in the south, 6 miles in
width; and a 24-foot deep channelcalled the Southwest Passage. Figures
I-6 through I-16 provide a pictorial introduction to the islands of the atoll.
SITE
ACRES*
Enewetak (Fred)
Enjebi (Janet)
Medren (Elmer)
Aomon(Sally)
Runit (Yvonne)
Japtan (David)
Lujor (Pearl)
Bijire {Tilda)
Ikuren (Glenn)
Lojwa (Ursula)
Aej (Olive)
Mut (Henry)
Enewetak Atoll was formed by the growth ofcoral reefs on an extinct
volcano (Figure 1-17). Coral reefs, and subsequently atolls themselves,
consist of limestone which is produced by coral animals (coelenterate
- polyps), coralline algae, and shelled animals. These living organisms
require warm, agitated water and strong sunlight to stay alive. This ts
particularly important to the coral animal forms since they are attached and
can only get food which drifts to them. Corals and other reef builders,
including algae, produce limy skeletons which, along with coral rubble,
sand and other sedimentary material, are bound together in a rock-like
mass by the limy secretions of the coralline algae. This continuous
production of limy skeletons and binding by the algae results in the
formation and growthof the cora!reefs.4
The rate of growth of coral teefs is relatively faster on the ocean side of
the volcanic mass than on the lagoon side because of more nutrition and
aeration in thewind-driven water.> Coral may grow vertically at an average
ries
with water depth and ceases completely when the coral is exposed by
variances in relative sea level. Such variances are associated with the
lowering of ocean levels during periods of glaciation. Thus, the growth rate
and morphologyare affected alternately by the submersion and subaerial
exposure of the reef. Once the coral colonies reach the surface or are
322
130
40
16
291
220
99
91
79
54
52
41
40
40
40
Boken (Irene)
Alembel (Vera)
118
89
40
37
32
22
21
17
16
16
16
38
Bokombako (Belle)
Boken (Irwin)
Ananij (Bruce)
Kidrenen (Keith)
15
31
29
25
24
Bokoluo (Alice)
Lou) (Daisy)
Kidrinen (Lucy)
12
12
10
10
22
21
20
Ribewon (James)
Mijikadrek (Kate)
Billae (Wilma)
GEOLOGY
HECTARES**
9
9
8
9
16
14
Biken (Leroy}
Bokenelab (Mary)
Elle (Nancy)
Bokinwotme (Edna}
Kirunu {Clara}
8
6
6
14
12
11
10
7
Van
5
5
4
4
3
7
3
Jedrol (Rex)
5
2
Taiwel (Percy)
5
2
Bokaidrikdrik (Helen)
Eleleron (Ruby)
Inedral (Uriah)
Jinimi (Clyde)
Jinedrol (Alvin)
2
4
4
3
2
Munjor (Tom)
Boko (Sam)
2
2
1
1
2
1
Bokandretok (Walt)
TOTAL
40 Sites
5
1
1
76,700,000 Sq.FT.
(2,75 Square Miles}
1,761 Acres
5
5
713
Hectares
*1 Acre = 43,560 Sq. Ft. = .405 Hectares
** 1 Hectare = 107,639 Sq. Ft. = 2.47 Acres
FIGURE 1-5. APPROXIMATE LAND AREAS, ENEWETAK ATOLL.