Circue-shaoed submarine scarp 220 m high, extending back 190 m inte the
node-n reef, and 1000 m alcng the rsef trend. The scarp exposed alder,
steeply dipoing beds belcw 220 m aling which the rockfall detached. They
samplec this exposure and the natural fere-reef slope surrounding it in
1°84 ard 1965 using a manned submersible. The natural slope in this area is
characterized by three zene: .1) the reef piate, crest, and near Tore reef
that extends fron sea level to -16 m, with a slope of less than 10/sup 0/,
(2: the bypass slope that extends from -16 to -275 m, with slepes of S5/sup
O/ decreasing to 35/sup 0/ near the base, and (3) a debris slope of lees
than 35/sup ¢/ below ~-275 m. Vertical walis, grecves, and chutes, common on
ether fore-reef slopes, are sparse cn the northwestern siepe of Enewetak.
The scarp exposes three stratigraphic units that are differentiated by
surficial appearance: (1) a near-vertical wall from the reef crest to 76 m
that appears rubbly, has cccasional debris-covered ledges, and is composed
mainiy of corals; (2) @ vertical te ceverhanging wall from -75 m to -220 m
thet i¢ massive and fractured, and has smacth, blocky surfaces; and (3)
inclined bedding beicw -220 m along which the slumo block has fractured,
exposing a dip siope of hard, dense, white limestone and delaomite that
extends Seiaw -400 m. Caves cccur in ali three units. Cpen cemert-lired
fractur2s and voids layered with cements are most commen in the middle
mit, which now lise within the thermocline. Along the sides cf the scare
epreod fore-reef boulder teds gipring at 2o/sup o/ toward the apes
:
the steerter (35/sup O/) digping natural surface truncates these ceds,
ch Gives evidence cf the erasionsl nature cf the bypass sicpe.
te 1032}
EQE-S7 2119509
Camma-ray spectrum of the radiacctive
super-hydgregen barb test excicsiia cn March 1, 1954
dust
preduced
oy tre
Sutnmor: shimizu, Sakae
Affiliation: byctea Univ., Japan
Cectererce Titles 3. international symocsium an radiation pnysics
Centerenze Lecetion: Ferrara, Iteiy Conference Gate: 39 Sep 1985
Scarce:
facil.
Instrum.
Methods Frys,
Fes...
Sect. &. (Netherlands) v
etai./é,.
Date: if far 19787
i?7-18e p.
aiden: NIMAE
Report Na.: CONF-@S0925-
Dacument Types Journal Article; Conference iiterature
Language: English
Journal Aarncuncement: EPBE707
Subfiles
INIS
(nen-US Atcmindex input AIX)
Work Location: Japan
Abstract: The super-hydrcgen bemb test explasion, the se-called Brava
test of a fission-fusien-fission bomb, was carried cut on Bikini Atel] in
thea mid-Pacific on March 1, 1954. Twenty-three Japanese fishermen en beard
@ fishing beat about 906 miles north-east cf the test site were attacked
urexpactediy by tne falleut, radicactive fine debris of coral reef. Within
several mantns after the accident Ev radiochemical analysis about 20
different meclides cf fission products and, in addition, a considerable
ancust ef “/fup 235/U were discovered fram the fallout. As we have been
prese-ving a minute amount ef the original fallout dust coliected on beard
the fisring boat 3i years age, measurements of ..gamma.. rays from it have
I004b34