we

After

fleet.

several hours,

the

snow-like material stopped falling on the

This cessation of fallout indicated that the cloud dispensing these

particles, probably extending about 100 miles
eastward.
105 nmi

(160 km)

across, had moved

The time of its passage over the inhabited atoll of Rongelap,

(194 km)

east of Bikini,

is not accurately known and can only be

inferred from its arrival at about 1430 at Rongerik farther east.

The

fallout reconstruction shown in Figure 61 shows the front of the fallout
passing the easternmost portion of Rongelap at 1245 local time.
At Rongerik, 135 nmi

(250 km)

east of Bikini,

25 men of the 6th Weather

Squadron operated a weather observatory for the Weather Reporting Element
(WREP), Test Support Unit, TG 7.4, and 3 men from the 9710th TSU operated
an ionospheric sounder for Project 6.6, TU 13, TG l.

BIKAR ATOLL

BIKINI

ATOLL

570

.

c
Vaoncerik aTout

.

ce

~

AILINGINAE ATOLL

\

UTIRIK ATOLL
TAKA ATOLL

\

U
0

10

Lot

20

a

30

40

S0

oem

60

70

80

90

Lot)

100

NAUTICAL MILES
Oo

\

20

40

i

60

J

80

100 120

140

160

renee

185

KILOMETERS

Figure 61.

CASTLE, BRAVO reconstructed fallout at H+6; 1245 local time
(R/hr). Reconstruction is by NRDL and shows gamma field

levels that would have existed had the fallout been on land

areas (source:

Reference 53).
216

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