226Ra in the Pacific Ocean

Chung, Y.; Craig, H.

doi:10.1016/0012-821x(80)90072-2

Cited by 109 publications

(48 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the deficiency of 226Ra down to a depth of 226Ra maximum, 226Ra flux at the sediment water interface for the core KH-80-2-9 was estimated to be 0.081 dpmcm-2y-1. This is enough to balance the decay of 226Ra in the overlying water column which is 0.06 dpm cm 2y-' based on 226Ra profiles reported by Chung and Craig (1980). The 226Ra deficits for the other three cores are small, corresponding to the steady-state flux of 0.017 dpm cm-2y-1 for KH-80-2-5, 0.009 dpm cm-2y-' for KH-80-2 6 and 0.012 dpm cm-2 y-' for KH-80-2-8.…”

Section: Radionuclide Inventoriesmentioning

confidence: 90%

Natural and man-made radionuclide distributions in Northwest Pacific deep-sea sediments: (rates of sedimentation, bioturbation and 226Ra migration)

et al. 1986

View full text Add to dashboard Cite

During the KH-80-2 Hakuho-Maru cruise in 1980, four sediment cores were obtainedd from abyssal basins of the western North Pacific. The cores were analyzed for U, Th, 231Pa, 226Ra, 210Pb, 239,240Pu and 137Cs. The sediment accumulation rates estimated from 230Th,,, and 23 'Pa,,, profiles yielded 0.4 to 1 cm/ky. The particle mixing coefficient, DB for top ^'10cm was also estimated from excess 210Pb profiles to range from 0.1 to 0.6cm2/y. Application of a mixing model with two different modes of input (pulse and continuous) showed limited success in reproducing the observed 239,240Pu and 137Cs. The DB values based on 239,240pu and "'Cs data and a continuous input model, however, are roughly equal to those based on 210Pbxs except for one core showing subsurface maxima for the fallout nuclides.

show abstract

Section: Radionuclide Inventoriesmentioning

confidence: 90%

Natural and man-made radionuclide distributions in Northwest Pacific deep-sea sediments: (rates of sedimentation, bioturbation and 226Ra migration)

et al. 1986

View full text Add to dashboard Cite

show abstract

“…Because the 1978 profile measurements were made at Scripps by the regenerated radon method (Chung and Craig 1980) and were calibrated against an NBS radium standard prepared for and adopted by the global GEOSECS program, we have normalized the radium profiles of 1963 and 1977 (Table 2) to the 1978 profile with respect to its deep water mean value. The mean and standard deviation of 18 measurements on six duplicate deep water samples of February 1978 are 97.7 and 2.7 dpmekg-I.…”

Section: Radium In the Dead Seamentioning

confidence: 99%

“…Contrary to a typical radium profile which shows a general increase with depth, in the Dead Sea the radium activity in the upper layers is greater than in the deep layers. The surface water radium content of the Dead Sea is about 1,600 times higher than that of the open oceans; in the deep waters Dead Sea meromixis and 226Ra it is only 250 times that of the deep waters of the northeast Pacific, which have the highest oceanic radium activities (Chung and Craig 1980).…”

mentioning

confidence: 92%

Radium in the Dead Sea: A possible tracer for the duration of meromixis1

Stiller

Chung

1984

Limnology & Oceanography

View full text Add to dashboard Cite

Three profiles of 226Ra in the meromictic Dead Sea measured during [1963][1964][1965][1966][1967][1968][1969][1970][1971][1972][1973][1974][1975][1976][1977][1978] indicate that the radium activities in the upper water mass were higher than in the lower water mass. All three profiles indicate a similar radium inventory. The Jordan inflow is not the primary source of radium to the Dead Sea. Mineral springs and submerged seepages are probably more important contributors.The age of the meromictic structure is estimated by a model which requires that the radium inventory of the lake be at a steady state, that sometime in the past the radium profile of the lake had been uniform (when either the lake was monomictic or an overturn had ended an earlier meromictic phase) and that the contemporaneous profiles of radium have been built up by inflows of radium solely into the upper water mass, while the monimolimnion is relict, isolated, and loses radium only by radioactive decay. Supporting evidence is presented suggesting that the above conditions may be fulfilled. Thus, it is possible to estimate that the Dead Sea was meromictic for about 300 years before the turnover in 1979.From tentative balances of the Dead Sea dissolved salts it is shown that a previous overturn might have occurred at a lower lake level than in 1979.The Dead Sea is a highly saline, terminal lake. It is physiographically divided by an east to west sill-the Lisan Straits-into a very shallow southern basin and a much deeper and larger northern basin (Fig. 1).According to Neev and Emery ( 1967), the lake level was maintained at about -436 m MSL, for a long time; that is, about 35 m lower than at present and the lake volume would thus have been restricted within its northern basin. Neev and Emery found supporting evidence that the level began to rise somewhat more than 1000 B.P. and that the waters of the Dead Sea have occupied both the deep northern basin and the shallow basin since about 500 B.P. High levels of the Dead Sea, -392 m MSL, were attained during the first three decades of the present century; since then the lake level has been decreasing, reaching ca. -403 m MSL in 1979(Klein 1965, 1981.Occasional chemical and physical analyses since 1864, and the detailed studies of Neev and Emery (1967) during 1959-1960

show abstract

“…This mode of introduction led Koczy to use radium data to derive vertical eddy diffusivities and velocities in the deep sea (Koczy, 1958). Since then, 226 Ra has been widely used to study the ocean circulation and mixing at a global scale (Chung and Craig, 1980;Ku et al, 1980). In the framework of the Geochemical…”

Section: Introductionmentioning

confidence: 99%

The <sup>226</sup>Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01

Roy¹,

Sanial²,

Charette³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract. We report detailed sections of radium-226 ( 226 Ra, T1/2 = 1602 y) activities and barium (Ba) 20 concentrations determined in the North Atlantic (Portugal-Greenland-Canada) in the framework of the international GEOTRACES program (GA01 section-GEOVIDE project, May-July 2014). Dissolved 226 Ra and Ba are strongly correlated along the GA01 section, a pattern that reflects their similar chemical behavior. Since 226 Ra and Ba have been widely used as tracers of water masses and ocean mixing, we investigated more thoroughly their behavior in this crucial region for thermohaline 25 circulation taking advantage of the contrasting biogeochemical patterns existing along the GA01 section. We used an Optimum Multiparameter (OMP) analysis to distinguish the relative importance of physical transport (water mass mixing) from non-conservative processes (sedimentary, river, or hydrothermal inputs; uptake by particles, and dissolved-particulate dynamics) on the 226 Ra from sediment and low 226 Ra/Ba ratios in the upper water column reflect the input of Ba associated with meteoric waters.

show abstract

226Ra in the Pacific Ocean

Cited by 109 publications

References 18 publications

Natural and man-made radionuclide distributions in Northwest Pacific deep-sea sediments: (rates of sedimentation, bioturbation and 226Ra migration)

Natural and man-made radionuclide distributions in Northwest Pacific deep-sea sediments: (rates of sedimentation, bioturbation and 226Ra migration)

Radium in the Dead Sea: A possible tracer for the duration of meromixis1

The <sup>226</sup>Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01

Contact Info

Product

Resources

About

226Ra in the Pacific Ocean

Cited by 109 publications

References 18 publications

Natural and man-made radionuclide distributions in Northwest Pacific deep-sea sediments: (rates of sedimentation, bioturbation and 226Ra migration)

Natural and man-made radionuclide distributions in Northwest Pacific deep-sea sediments: (rates of sedimentation, bioturbation and 226Ra migration)

Radium in the Dead Sea: A possible tracer for the duration of meromixis1

The &lt;sup&gt;226&lt;/sup&gt;Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01

Contact Info

Product

Resources

About

The <sup>226</sup>Ra-Ba relationship in the North Atlantic during GEOTRACES-GA01