weetke
and ty, the mean life of radiocarbon
(that is, 8040 years).
Tame 1. Concentrations of Ra*** and Rn?“ in the oceans. A, specific activity.
Sample
No.
Position
Depth
Longitude
Latitude
(m)
Sample
Ra
(liters }
g/liter)
volume
_
(10
An
Ara™
[Q — Cs /Co)a/( — Cs’] Co’)?]
Northwest Pacific Ocean
(Vema-21, leg between Hawaii to Tokyo}
29
26
20
17
27
23
5
150
300
450
600
600
800
1000
22
24
19
1250
1500
2000
3000
4000
4600
5060
7
15
10
25
158°50°E
166°04’E
172°45°'E
176° 16E
162°31’E
169°02’E
165°14°W
169°02’E
169°02’E
172°45'E
169°41°W
179°2VE
173°14"W
166°04’E
28°47'N
27°05'N
25°3N
24°53’N
27°54N
26°26'N
22°14N
26°26'N
' 26°26'N
25°31N
22°S51’N
24°31'N
23°27N
27°0S'N
As shown above Cp ~ Cg is 12 X 10-14
g/liter for the Pacific, and for x10—14
*
*
*
*
*
*
3.70.1
38+ .1
37 2
53a 2
§Ot 2
692 4
91a 3
10.9 4
118% .4
12.9 2
14.2 2
lol 4
161+ 4
15.12 .3
~~ 39
a 39
~ 39
~ 39
~ 39
om 39
~ 39
~ 39
~ 39
mm 39
~ 39
~~ 39
~ 39
~ 39
g/liter for the Atlantic. Radiocarbon
data (4, 6) yields Cy’/C)’ of approximately 0.85 for the Pacific and 0.95 for
the Atlantic, hence
*
*
*
*
*
*
*
*
In/la = {C12 X 10-14)/(4 X 10-14)] X
[(1 — 0.95)/(1 — 0.85)] = 1
Therefore, the threefold longer residence
time of water in the deep Pacific allows three times more radium to accumulate.
In this calculation the difference in
concentration of radium generated by
radioactive decay was neglected. If the
mixing rates based on radiocarbon data
are valid, then the decay of radium
introduces only a 12 percent difference
East Equatorial Pacific Ocean
(Conrad-10, leg between Panama to Monzanille)
48
45
47
39
200
400
720
1060
02°48'N
02°41’°S
01°19.6’N
01°49N
41
1510
05°36'N
49
50
37T
4Tt
2500
3100
3230
3790
03°33’N
06°S50’N
03°51.5'N
01°19.6’N
46T
4270
02°41’S
115°54.5°W
98
36
36
36
36
42+03
50+ 3
56 3
100+ 4
*
*
2
®
96°10°W
36
109
4
*
113°12.5'°W
110°27°'W
85°57. W
114°50.5'W
36
36
36
18
12.8
13.72
14.2
15.62
4
4
5
8B
*
*
1.82 + 0.07
1.562 .09
18
15.6
8
1.662
.
Northwest Atlantic Ocean
(Conrad-10, leg between Bermuda to Jamaica)
24°47,.2'N
0
9
8
7
11
10
3
5
12+
113°36°W
115°54.5'W
114°50.5°W
91°14-W
200
530
1070
2250
3290
4820
5110
5600
54°59.5'W
24°47.2’'N
25°31.5'N
25°10.8°N
21°44.2°N
22°50'N
29°46’N
26°25.3'N
21°44.2N
* Assumed to be unity,
§4°59.5°W
55°14.5°W
§6°06.5°W
61°27.8°W
§7°52.3°W
62°26'W
58°37.8°W
61°27.8'W
36
4.0+03
36
36
36
36
36
36
36
36
4ixt
490+
422
6.24
73a
81l—
90+
8.1m
3
3
3
3
3
4
4
4
volume roughly 10 times greater than
the surface ocean).
The equality of the concentrations of
radium between the surface waters of
the two oceans may havesignificance to
on
Sample
Depth
(m)
Latitude
Longitude
1
3
8
13
14
Surface
Surface
Surface
Surface
Surface
20°51’N
21°36'N
22°SUN
24°31‘N
24°31N
158°09°W
161°26°W
169°41°W
179°2VE
179°2 VE
18
21
28
Surface
Surface
Surface
25°31N
26°26’°N
28°47'N
172°45’E
169°02'E
158°50°E
31
32
Surface
Surface
No.
16
30
Surface
24°58’N
176°16'E
154°36’E
(liters)
~
~
~
~
~
g/liter)
( Ani™ )
Ag.™
39
39
39
39
39
19+0.1
24> 2
16+ 2
25 .2
2.2 2
0.48
54
41
64
56
~ 39
~~ 39
~ 39
19% 2
2l+ Jl
20-7 .1
48
54
51
~ 39
Finally, there is no evidence for any
significant gradient in radium away
from the sediment interface. Within the
limits of error, our measurements indicate that the radium content of the
deep sea is constant below 3000 m.
Any gradient that is present probably
54
a knowledge of the vertical distribution
29°SI’N
30°04’'N
150°58’E
147°41'E
~ 39
~~ 39
20+ 11
224+ 2
51
56
33
Surface
30°25‘N
144°30°E
am 39
19>
(1
48
2
4
11
12
29
26
25
25
25
75
150
300
20°SUN
22°14'N
23°27 N
23°58’N
28°47°N
27°05’N
158°09°W
165°14"°W
173°14°W
176°SUW
158°50°E
166°04’E
~
om
nm
~
~™
~
25+
284
254
3.02
374+
3.84+
2
2
2
1
1
2
65
72
65
TT
1.95
1.98
1308
the problem of interocean mixing. Un-
less it is a coincidence, it suggests that
the surface waters of the Atlantic and
Pacific intermix with each other more
frequently than they intermix with the
underlying deep water masses.
reflects the same phenomena that produce salinity and temperature gradients
{see Munk (7)]. To gain any further
— 29°28'N
39
39
39
39
39
39
214 1
*
surface ocean (the deep ocean has a
.80
Surface
* Assuming Ra*™® is 3.9 > 10-™ g of radium per liter,
—~ 39
314 1
is predicted to show a smaller decay
0.65 + 0.05
*
*
x
*
*
*
*
1.64 = 0.09
Rn™
(10-"
surface water of the Pacific. The fact
that, despite its shorter half-life, radium
effect than radiocarbon results from its
addition to the deep rather than the
Table 2. Concentrations of Ra”™-Rn'* in near-surface water from the Northwest Pacific
Ocean (Vema-21, leg between Hawaii to Tokyo). A, specific activity. Radon concentrations
are given in radium equivalents.
Sample
volume
in its concentration between deep and
.09
+ Samples taken 22 m above the sea bottom.
Position
Iefla = [(Co — Cs)e/(Co — Cas] X
information from radium would require
of the resolution of falling particles. At
the present time we do not even know
the nature of these particles.
The next step in understanding the
distribution of radium in the sea re-
quires the precise measurement of the
ratio of Ra®** to barium. If these two
elements have identical chemistry, these
ratios can be used in the same manner
SCIENCE, VOL. 158