The Effect of Atmospheric <sup>14</sup>C Variations on the <sup>14</sup>C Levels in the Jordan River System

Carmi, Israel; Stiller, M.; Kaufman, Aaron

doi:10.1017/s0033822200007104

Cited by 16 publications

(18 citation statements)

References 12 publications

(17 reference statements)

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“…Hence, the correlation between the ␦ 13 C atm and the sedimentary ␦ 13 C car implies that the Jordan River waters and its allochthonous carbonate (from which about 40% is due to authigenic precipitation within the Jordan River; Stiller et al 1988) are sensitive to changes in ␦ 13 C atm . A similar conclusion was reached by Carmi et al (1985) based on 14 C measurements and is supported by (only) three ␦ 13 C DIC measurements in the Jordan River showing a change from Ϫ6.3‰ to Ϫ7.4‰ and then Ϫ9.8‰ from 1972 to 1983 and 1998, respectively (Stiller et al 2001). Nevertheless, considering various anthropogenic activities in the lake's watershed that might also affect the ␦ 13 C DIC of the Jordan River (such as drainage from fish ponds and irrigated land crops), ␦ 13 C atm changes over the past few decades probably were not the sole driving force for these observed trends.…”

supporting

confidence: 62%

Isotopic paleolimnology of Lake Kinneret

Dubowski

Erez

Stiller

2003

Limnology & Oceanography

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The carbonate, organic C, and N contents and their respective ␦ 13 C were measured in four cores from Lake Kinneret, Israel. Using these data and the isotopic difference between coexisting carbonate and organic C, ⌬␦ 13 C, we attempted to reconstruct the lake's productivity and regional climatic conditions during the late Holocene. The sedimentary record of the last 120 yr (for which climatological data are available) demonstrates that during periods of intense productivity, organic C content and its ␦ 13 C org are high, whereas the ⌬␦ 13 C values are low. During wet periods, characterized by intense input of particulates and nutrients from external sources, the CaCO 3 content, its ␦ 13 C car and ␦ 18 O car , and the organic C : N ratios are low. Based on these correlations, the longer sedimentary record of the last ca. 3,300 yr was divided into five stages, which differ in productivity and/or climatic characteristics. This longer sedimentary record indicates that the primary production in Lake Kinneret has varied in the past over a range similar to that observed presently, but the rate of these changes was much slower. The rainiest period recorded in the sediments was from about 200 B.C. to A.D. 200, i.e. during the Roman period, when the region was heavily populated. The recent decrease in ␦ 13 C of atmospheric CO 2 that accompanies the global anthropogenic CO 2 rise seems to be recorded by a commensurate decrease in ␦ 13 C car of the sediments. The concomitant increase in ⌬␦ 13 C expresses an increase in the isotopic fractionation of the lake's primary producers, which may also be related to the atmospheric CO 2 rise.During the last decade it has been well established that the C isotopic fractionation of marine and freshwater phytoplankton is controlled by their rate of growth, the ambient concentration of dissolved CO 2 (CO 2(aq) ), and the phytoplankton size and shape (e.g, Degens 1969; Goericke et al. 1994;Laws et al. 1995;Rau et al. 1996). Thus, the fractionation of C isotopes is becoming an important tool for deciphering paleoenvironmental changes in aquatic systems (e.g., Hollander et al. 1993;Jasper et al. 1994) Because of their smaller size and higher sedimentation rates, lakes are more sensitive than oceans to climatic and environmental changes. Their sedimentary records therefore allow finer time resolution and direct comparison with known historic and climatic records on nearby land. Lake Kinneret (35Њ31ЈE, 32Њ53ЈN) is a warm monomictic lake characterized by an annual winter-spring bloom of Per-1 To whom correspondence should be addressed. Present address: Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 54-1320, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (yaeldu@mit.edu). AcknowledgmentsThis research was supported by the Belfer Foundation for Energy Research, by grant DISUM-BMBF 0033-01421 from the Israeli Ministry of Science and the German Ministry of Science and Technology, and by the Moshe Shilo Minerva Center for Marine Biogeoc...

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confidence: 62%

Isotopic paleolimnology of Lake Kinneret

Dubowski

Erez

Stiller

2003

Limnology & Oceanography

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“…The validity of 14 C ages depends on correct assessment of equilibrium between the precipitating CaCO 3 and atmospheric CO 2 . Schramm et al (2000) estimated a reservoir age of 1.0 ka, based on 14 C data on organic material and aragonite, and measurements of Dead Sea water (Carmi et al, 1985) collected before the 1978 overturn. Our updated evaluation indicates a best fit with the coral data if the reservoir correction is 1.2 ka.…”

Section: U-th and 14 C Agesmentioning

confidence: 99%

U-Th dating of Lake Lisan (late Pleistocene dead sea) aragonite and implications for glacial east Mediterranean climate change

Haase-Schramm¹,

Goldstein

Stein

2004

Geochimica et Cosmochimica Acta

186

139

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“…A 14 C DIC between Dan source and Arik bridge is 23 pMC according to Carmi et al [1985], and 13 pMC in this study; see Table 1 value, as compared to the 14 C content of its tributaries (water sources). Ε is defined by the equation (Carmi etal.…”

Section: Dissolution Reactions and Carbon Isotopes In The Perennial Smentioning

confidence: 52%

“…Moreover, previous studies have shown that the RA varies considerably between the water sources of the lakes (e.g. Carmi et al 1985;Talma et al 1997).…”

Section: Introductionmentioning

confidence: 95%

Controls on the Radiocarbon Reservoir Ages in the Modern Dead Sea Drainage System and in the Last Glacial Lake Lisan

et al. 2007

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ABSTRACT. Carbon isotopic and chemical compositions of freshwaters feeding the Dead Sea and the Sea of Galilee (i.e. perennial streams and floods along their stream profiles) were used to constrain the factors that dictate the reservoir ages (RA) of these lakes and the last glacial Lake Lisan. Runoff waters are characterized by high Ca 2+ , Mg 2+ , alkalinity, and radiocarbon contents (67-108 pMC), suggesting a major role for ,4 C atmospheric exchange reactions (carbonate rock dissolution alone will result in lower pMC values). These exchange, processes were corroborated by dissolved inorganic carbon (DIC) and Ô 13 C trends throughout the flood profile. During the evolution from rain to incipient runoff, the 14 C DIC of the water increases and is accompanied by a DIC increase and Ô 13 C DIC decrease, suggesting an addition of soil C0 2 , which is characterized by light ô ,3 C and high 14 C content. When incipient runoffs evolve to floods, the opposite trends are observed.It appears that the Sea of Galilee, the Dead Sea, and its last glacial precursor, Lake Lisan, maintained uniform but specific RAs of 0.8 ±0.1, 2.3 ±0.1, and 1.6 ± 0.3 kyr, respectively. However, applying the 14 C contents of modern Dead Sea water sources to the water mass balance of Lake Lisan reveals that the RA of Lake Lisan is higher than that predicted by the mass balance. This discrepancy may reflect enhanced dissolution of carbonatic dust, changes in the amount of 14 C exchanged in Judean Desert floods, or variations in the contribution of brine and saline springs. Furthermore, the small fluctuations in the Lisan RA (1.6 ± 0.3 kyr) may reflect small, short-term changes in the relative contributions of these sources.

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The Effect of Atmospheric ¹⁴C Variations on the ¹⁴C Levels in the Jordan River System

Cited by 16 publications

References 12 publications

Isotopic paleolimnology of Lake Kinneret

Isotopic paleolimnology of Lake Kinneret

U-Th dating of Lake Lisan (late Pleistocene dead sea) aragonite and implications for glacial east Mediterranean climate change

Controls on the Radiocarbon Reservoir Ages in the Modern Dead Sea Drainage System and in the Last Glacial Lake Lisan

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The Effect of Atmospheric 14C Variations on the 14C Levels in the Jordan River System

Cited by 16 publications

References 12 publications

Isotopic paleolimnology of Lake Kinneret

Isotopic paleolimnology of Lake Kinneret

U-Th dating of Lake Lisan (late Pleistocene dead sea) aragonite and implications for glacial east Mediterranean climate change

Controls on the Radiocarbon Reservoir Ages in the Modern Dead Sea Drainage System and in the Last Glacial Lake Lisan

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The Effect of Atmospheric ¹⁴C Variations on the ¹⁴C Levels in the Jordan River System