for low-frequency sound waves.
Some success had been achieved during both Greenhouse
and Ivy in detecting SOFAR signals transmitted through the water.
Relative yields were
fairly well established from signals received during Greenhouseat oneof the detecting
stations. It was planned to again activate these remote stations for Castle to make
special observations of acoustic pressure signals of the SOFAR type, to add to the knowledge of underwater sound propagation, and to investigate the possibility of determining
yields.
Shots 2, 4, 5, and 6 were monitored by detecting stations located on the California
coast and at Bermuda. No clear-cut signals were recorded which could be attributed to
TABLE 2.4
SUMMARY OF PRESSURE-TIME DATA, SHOT 6
Buoy D3, 9,300-ft
Buoy Al, 16,100-ft
Distance
Depth, ft;
50
Channel:
100
i
2
100
Distance
100
3
4
«0
40
78
3
3
6
Blre Box
from Zero
Pressure Arrival
Time, sec
0
0
0
0
2.14
_
2.08
0.97
0.97
0.96
0.96
1.27
_
1.67
Pressure A, psi
Time, sec
19.27
1.06
18.2
1.06
16.3
1.05
17.25
1.06
17.4
1.85
_
_
24.2
1.78
Pressure B, pai
Time, sec
82.7
1.38
84.3
1.37
64.5
1.36
84.5
1.36
28.9
1.89
—_
_—
~35.6
1.83
Preasure C, pai
Time, sec
74.7
1.40
—56.6
1.40
—62
1.39
—36.6
1.40
316.8
1.94
—_
_
24.2
1.89
Pressure D, psi
Tine, sec
Pressure E, psi
Time, sec
Gage
Amplitfier
88.4 |
1.64*
78
1.65*
92.2
1.64*
16.1
1.64*
15.78
2.37
_
_
25.3
2.30
_—
_
~
—_
_
_
$2
4.90°
—_
_
20
4.81°
_
_
PE
log
PE
Un
PE
PE
Mat
logt
PE
log
Wianckot Wiancko
_
_
*Air blast, based on arrival time.
f Same gage.
£ Equipment tnoperative.
sources at either Bikini or Eniwetok.
It is concluded that the position of the shots inside
the lagoon and on the atoll rim was such as to preclude coupling of energy into the SOFAR
channe] in the frequency range for which instruments were available. Another factor
which might have prevented reception at the California stations was the presence of shoal
areas between the Bikini atoll and the coast along the most likely path of travel.
2.7
SURFACE WATER WAVES
The effects of water waves resulting from megaton-yield detonations at the surface
could have military significance for (1) generation of waves in harbors causing damage
to secured. vessels, docks, shore installations, etc. and (2) long-range propagation of
tsunami-like waves from a source over deep water, which could produce serious damage
over extensive coastal areas.
The only previous full-scale data on water waves generated from a megaton surface
burst had been obtained from Ivy Mike. No measurable waves were produced in the
central region of the detonation, yet waves which were of measurable amplitude were
observed at a range greater than four miles.
38
These waves increased in height out to a