cs
-Neluded all the ¥
8
twice daily,
e-week periods
(LCM) and on
lagoon and
= bucket hauls
“Study periods,
observations
Ons at various
L observations
8
ll values are
pendix III,
—
hoped none1 Supplement-
or listed in
ts several
Chain.
eines
nly
In addition to these two main chains there are several isolated outlying
atolls.
Altogether the group contains twenty-nine atolls, five islands having
no interior lagoon and two, known,
submerged banks shallower than ten fathoms.
The highest land elevation within the group is about twenty-eight feet.
Eniwetok is an isolated atoll lying west of the Ralik Chain and is located
some 2,500 statute miles west-southwest of Honolulu, Hawaii and some 4,700 miles
from San Francisco.
The atoll is some 190 statute miles due west of Bikini
Atoll, which together with Ujelang, located some 130 miles southwestward from
Eniwetok,
are the closest exposed land areas.
It appears that Eniwetok Atoll
wag originally a volcanic cone, since basalt was found there in 1950 as a result
of several deep drilling explorations.
The cone probably initially emerged some
feet above the water and later was eroded away and absorbed by wave and water
action.
When the critical depth of sea water required for coral existence and
growth was reached by the emerging cone,
coral growth probably began.
Today Eniwetok Atoll consists of a chain of about thirty small, low islets
surrounding an oval lagoon 25 miles long by about 20 miles wide (Figure 1}.
The
total dry-land area of these islets 1s only 2.5 square statute miles compared
with a total lagoon area of 360 square statute miles.
The total reef area
exposed at low tide is about 32 square statute miles.
Most of the islets are
less than 13 feet high but are,
in some instances,
reaching up to 8O to 100 feet above low tide level.
the reef.
covered by coconut palms
Three entrances penetrate
Deep Entrance at the southeast side is only about 3/4 of a mile wide
' lying north
but it has a depth of 31 fathoms between ELMER and Japtan Islets
(Figure 1).
ed at
South Channel,
and is usually
nds
known as Wide Passage.
are
on the other hand,
is very wide,
about six miles,
Charted depths in Wide Passage are only 6 to 12 fathoms.
nwestward,
Southwest Passage on the west side ig even shallower, having depths of only about
ee
1 fathom.
nN Was
Wide Passage have been observed.
Maximum tidal currents of two knots in Deep Entrance and of 1 knot in
The Eniwetok lagoon is nearly elliptical with its long axis trending north-
his pupli-
westward.
The deepest area is in the north central part of the lagoon, which is
the area farthest from the main passes
through the reef (Figures 1 and 2).
If
—
the numerous superimposed coral mounds were ignored, the bottom contours would
-K (Sunset)
show a smooth slope from depths of about 24 fathoms near FRED northwestward to
the deepest point of the lagoon, about 35 fathoms.
Tr enamine am Ie
There appears to be no
ee nS ot ne
“f