evidence availatle fron the analysis of the particle trajectories.
The
Maximun lateral dimension of the fallout pattern as indicated in Fig.6.5
agrees well witu the constructed pattern. The density of arrival points
Snould te related t. the levels of activity; this offers rurther reason
to construct tue area of peak activity to the norta of Rongelap Atoll.
4.2.8
Eveluation of the Snot 1 Fallout Fattern
To deterwine tie time of arrival of fallout, Pig. 6.13 was con-
Structed bese on the times as deternined fron the particle trajectory
analysis. Incluied in the analysis wes the effect of the cloud direnSions. Comparison of this calculated tire of arrival with the reporie
time of errival cn the cuter islanis indicates the validity of the
calculated rates of fall of the particles.
™~\
comparigcon.
TALE 6.6
Table 4.5 presents tunis
— Shot 1, Comparison of Calculated and Observed Times of
Arrival of Fallout
Distance
Calculated Time
Observed Tire (a)
4
50
a7
190
12
lel
2.1
Le7
5.9
7.8
1
7
8
150
ll.
13.2
15.4
8.9
18
(n miles)
of Arrival (hr)
200
250
302
(a)
of Arrival (hr)
-
Taken from Reference 1.
The reliability of the observed *imes of arrival on the atcils
innebited by natives ere open to some question because of poor documentation. Tic appears to be especially true of the 7 hr crrival tine
at the atoll of Rongelap. ‘ne weather island of Rongerik st 126 nautiCal miles reported o:erved arrivel times trat compare well with the
Calculated values.
An attespt to deternire the average period of fallout was made
by eveluating the trajectory data as shown In Fir. 6.13. This was done
by obtaining an averege time of cessation of fallout.
‘the rate of
arrivel cf fellout at How Islind vwaured the majerity of the activity
to te deposited early in the total reriod of fallout (see Section 5.7).
Cn the basis of this otservation the curve indicatine the time of cessa-
tinn of fellout (Fig. 6.13) was weighted showing the period of fallout
ending before all particulate hud arrived.
level of ganna activity peaks.
{t is at tuis time that the
Continuing falleut after inis time is of
88