Radioactivity in the Marine Environment (1971) / Chapter Skim
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OCEANIC DISTRIBUTIONS OF RADIONUCLIDES FROM NUCLEAR EXPLOSIONS
OCEANIC DISTRIBUTIONS OF RADIONUCLIDES FROM NUCLEAR EXPLOSIONS
Pages 42-89
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From page 42... ...
The rate has certainly increased in the last few years; in 1966, about 650 samples of ocean water were collected for fallout study, almost 20 percent of the number on land. Thus, we might reasonably conclude that, considering the area of the ocean surface (nearly three times that of the land)
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From page 43... ...
While this may appear less than satisfactory as a purely scientific endeavor, we consider the overall benefit derived from maintaining this group of authors to be of greater value. 90Sr IN SURFACE OCEAN WATER Strontium-90 has been measured in surface water samples since 1954 in the Atlantic Ocean and starting in 1957 in the Pacific Ocean.
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From page 44... ...
-- so NO >0 !
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From page 45... ...
n ~ £ 10 fT ^ « -- fl Q > r7 oo o -~ ' '-^ .
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From page 46... ...
. cdpm/100 liters + mean deviation; numbers in parentheses are numbers of analyses.
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From page 47... ...
. cdpm/100 liters ± mean deviation; numbers in parentheses are numbers of analyses.
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From page 48... ...
reports the results of measurements of 90Sr concentration in surface waters from the eastern North Pacific made periodically since late 1964 and states that no significant seasonal variation was observed. Bainbridge (1963b)
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From page 49... ...
c SSS5 .ciS^I^ g 1 1 1 1 I 1 " '+,' - •+,.•'•• ' *
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From page 50... ...
41 (2) TABLE 7 Pacific Ocean 90Sra Comparisons Year Latitude Band Country 90SrConc.6 Reference Western Pacific 1961 20°-30°N United States Soviet Union 47 ±9 (4)
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From page 51... ...
90Sr IN OCEAN WATER FROM SURFACE TO 700 METERS Atlantic Ocean Measurements of 90Sr in water samples from depths of 700 m or less in the Atlantic Ocean have been collected; they are summarized in Tables 9 and 10. In the section of this chapter on the inventory of 90Sr in the ocean (p.
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From page 52... ...
52 Radioactivity in the Marine Environment TABLE 9 Mean 90Sr" Concentrations in Atlantic Ocean Surface to 700-m Profiles-Northern Hemisphere 1957 1958 1959 1960 1961 Depth (m)
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From page 53... ...
Oceanic Distributions of Radionuclides from Nuclear Explosions 53 1962 1963 1964 1965 1966 1967 Ref.6 Conc.c Ref.6 Conc.c Ref.6 Conc.c Ref.6 Conc.c Ref.6 Conc.c Ref.6 Conc.c 2, 3, 4, 5 78±18(24)
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From page 55... ...
. Surface values are dpm/100 liters ± mean deviation; subsurface values are percent of surface values; parentheses indicate number of analyses.
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From page 56... ...
These data TABLE 13 Mean 90Sr Concentrations in Atlantic Ocean and Caribbean Sea Deep Water 1957 1958 1959 1960 1961 Depth (m)
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From page 57... ...
. All the available deep water analyses of 90Sr are summarized in Tables 13 (Atlantic Ocean and Caribbean Sea)
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From page 58... ...
64 Radioactivity in the Marine Environment TABLE 13 (Continued) 1957 1958 1959 1960 1961 Depth (m)
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From page 59... ...
- 9 5 (1) -- -- - -- -- - -- -- -- -- -- - -"Values are dpm/100 liters ± mean deviation or reported error if only one analysis; numbers in parentheses are number of analyses.
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From page 61... ...
I 1 I I I - 1 1 1 I o O fN so (*
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From page 62... ...
If they show a large spread, the validity of even the surface values for that investigator are open to serious question. Penetration of Fallout Strontium-90 into Deep Water of the Atlantic Ocean Vaughan T
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From page 63... ...
However, it should be pointed out that if 137Cs or 90Sr are to be exploited as tracers of ocean water masses, only the ionic component should be measured. I feel that ionic 137Cs and 90Sr are excellent tracers for studying ocean circulation and mixing processes and that in the absence of advective processes, as in the case studied above, there has been no exchange between surface and deep waters in the time frame represented by the history of global fallout.
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From page 64... ...
The parameter x1/2 (called the half mixing depth) is the depth at which the surface water excess (i.e., Cs - CD)
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From page 65... ...
THE RATIO OF 137Cs TO 90Sr IN SEAWATER Radiochemical analysis of most environmental samples studied in the investigations of nuclear fallout (stratospheric air, tropospheric air, and precipitation) yielded 137Cs/90Sr ratios generally ranging between values of about 1 and 3 (Friend etal., 1961; United Nations Scientific Committee on the Effects of Atomic Radiation, 1964, 1966; Hardy and Chu, 1967)
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From page 66... ...
Component Component Total Land Extrapolation 1961 0 7.0 0 7.0 3.2 3 6.1 18.4 24.5 1966 0 14.3 0 14.3 7 fi 3 13.1 18.4 31.5 TABLE 18 Ratio of 137Cs to 90Sr in the Atlantic Ocean Year Reference Surface Water 1961 1.5 ±1.0 (6) Kautsky, 1968, personal communication .7±0.2(2)
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From page 67... ...
the stratosphere, and is subsequently brought down into the troposphere, where both precipitation and molecular exchange serve to transfer the tritium into the surface ocean water. Hence, tritium could probably be called the ideal tracer for ocean water movements, and in light of the time elements involved since the major injections into the atmosphere and the probable concentrations in the sea from natural sources, it should be extremely useful in studies of rates and mechanisms of surface water movements.
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From page 68... ...
A detailed examination of this relationship might be expected to be quite illuminating with respect to mechanisms of overocean fallout. 14C IN THE PACIFIC OCEAN The distribution of radiocarbon in the Pacific Ocean is best discussed under three headings: in the deep water, in the surface water, and in vertical profiles.
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From page 69... ...
27* N FIGURE 5 Seasonal characteristics of 14C content in the surface water of the North Pacific Ocean, 155°W.
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From page 70... ...
. In the case of 91Y, Bowen and co-workers have a large number of still unpublished analyses of North Atlantic surface water samples taken early in 1962; by about June of that year, they found 91Y no longer determinable in 55-liter samples.
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From page 71... ...
(1968) report that the relative abundance pattern of lanthanide elements appears to be a conservative property and to distinguish in the Atlantic such water masses as North Atlantic Deep Water, Antarctic Intermediate Water, and Antarctic Bottom Water from each other.
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From page 72... ...
Rudjer Boskovic Institute (1964, 1965, 1966) United Nations Scientific Committee on the Effects of Atomic Radiation (1964, 1966)
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From page 73... ...
This report summarizes the results of surface water analyses of 779 samples from the Atlantic Ocean, 1,181 from the Pacific Ocean, 96 from the Indian Ocean, and 543 from various seas. These results were reported by more than 20 different investigators from 8 different countries.
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From page 74... ...
In the eastern equatorial Atlantic, the thermocline appears to completely insulate the deeper layers from tritium penetration; however, north of about 15°, tritium was found at depths in excess of 2,000 m, with no systematic vertical discrepancy from 90Sr. Radiocarbon, studied in the northeastern Pacific Ocean, indicates no penetration below 200 m and a very strong latitude dependence in surface water.
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From page 75... ...
1968. Fallout 90Sr in Atlantic Ocean surface waters.
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From page 76... ...
1963. The 137Ce content of the surface waters of the Atlantic Ocean and the adjacent seas in 1961.
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1966. Fallout in the North Pacific Ocean.
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From page 78... ...
1960. Strontium-90 in Western North Pacific surface waters.
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From page 79... ...
1962. 90Sr in the surface waters of the Atlantic Ocean.
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From page 80... ...
1967. The uptake of bomb tritium and C-14 by the North Atlantic Ocean.
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From page 81... ...
1967. Radioactivity in the North Pacific Ocean.
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From page 82... ...
1962. Information on the radioactivity of the Pacific Ocean water.
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From page 83... ...
1968. Fallout radioactivity in the North Pacific Ocean: Data compilation of 90Sr and i 37Cs concentrations in seawater.
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From page 84... ...
H Carter INTRODUCTION Radioactive isotopes introduced into the marine environment are subjected to the same physical, chemical, and biological processes that affect nonradioactive isotopes in the same physical state.
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From page 85... ...
A mathematical model of the process would therefore include an added term to account for this added vertical flux. If the material is introduced into the marine environment in a solution having significantly different density than the receiving waters, then the early fate of the radioactive material may be influenced to a considerable degree by the manner of introduction.
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From page 86... ...
. These workers have examined the bivariate distributions of potential temperature and salinity in the Pacific, Indian, and Atlantic oceans, respectively.
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From page 87... ...
The Atlantic Ocean, on the other hand, has a dominant mode centered at a potential temperature of 2.25°C and salinity of 34.95 per mille. This is primarily associated with the North Atlantic Deep Water.
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From page 88... ...
- l/•> u. J-j S u Bo C/3 ssssss .^ M V ' South Atlantic Central V Antarctic Intermediate \ Subantarctic Water Antarctic Circumpolar V South Atlantic Deep anc Antarctic Bottom Water C Eastern South Pacific W; Western South Pacific W Antarctic Intermediate > Subantarctic Water Pacific Deep Water and / Water Mith Atlantic ex NO v> 7 V -r s> op v> auth Pacific Oceans0 H i 1 1 1 1 o on -- r 1 .'.'.
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From page 89... ...
es ^ Ol a.
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