Aaron Kaufman
Dados Biográficos
| ID | 5598521 |
|---|---|
| NOME | Aaron Kaufman |
| PRENOMES | Aaron |
| SOBRENOME | Kaufman |
| ASSINATURA | KAUFMAN A |
| AFILIAÇÕES | Weizmann Institute of Science |
| VERIFICADO | Não |
| TOTAL DE OBRAS | 11 |
| TOTAL DE CITAÇÕES | 18 |
| TOTAL COMO AUTOR | 11 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1980 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2003 |
| ÍNDICE H | 3 |
Paleoclimate reconstruction based on the timing of speleothem growth and oxygen and carbon isotope composition in a cave located in the rain shadow in Israel
High-resolution 230 Th/ 234 U ages and δ 18 O and δ 13 C compositions of speleothems in Ma’ale Efrayim Cave located to the east of the central mountain ridge of Israel enable us to examine the nature of the rain shadow aridity during glacial and interglacial intervals. Speleothem growth occurred during marine glacial isotopic periods, with no growth during the two last marine isotope interglacial intervals and during the peak of the Last Glacial …
Spatial Variations of Radiocarbon in the Coastal Aquifer of Israel—Indicators of Open and Closed Systems
The spatial variation in radiocarbon concentration was studied in the Coastal Aquifer of Israel. Lower concentrations were found in the western section of the aquifer (55–70 pMC) as compared to the eastern section (80–100 pMC). Since no correlation was found between the tritium and radiocarbon values, these variations could not simply be explained by a difference in ages, or by a difference in the degree of old calcite dissolution as similar δ 13…
Calibration of Lacustrine Sediment Ages Using the Relationship Between 14 C Levels in Lake Waters and in the Atmosphere
The source of endogenic organic and inorganic carbon in lacustrine sediments is the dissolved inorganic carbon (DIC) in the lake water. The relation between the radiocarbon levels of DIC in Lake Kinneret and of CO 2 in the atmosphere has been investigated. The ratio of the former to the latter was found to be 0.814 ± 0.013. This ratio is used for calibrating the age of the sediment according to the natural fluctuations in the atmospheric levels o…
The Eastern Mediterranean paleoclimate as a reflection of regional events
Petrography, strontium, barium and uranium concentrations, and strontium and uranium isotope ratios in speleothems as palaeoclimatic proxies
The reconstruction of the palaeoclimate of the eastern Mediterranean region for the last 60 ka BP is based on theδ 18 O andδ 13 C variations of speleothems from Soreq Cave, Israel. Climatic conditions during most of the time interval between 60 and 17 ka BP (the period equivalent to the last glacial) were relatively cold and dry, while they were warmer and wetter from 17 ka BP to the present. At ~17 ka BP, there was a major climatic change with a…
Late Quaternary Paleoclimate in the Eastern Mediterranean Region from Stable Isotope Analysis of Speleothems at Soreq Cave, Israel
The eastern Mediterranean continental paleoclimate during the past 25,000 years was determined by a high-resolution petrographic, stable isotopic, and age study of speleothems from Soreq Cave, Israel. δ 18 O–δ 13 C trends indicate that all speleothems older than 7000 yr formed under conditions that differ from those of today. The period from 25,000 to 17,000 yr B.P. was characterized by the highest δ 18 O and δ 13 C values, which indicate deposit…
Reevaluation of the Lake-Sediment Chronology in the Dead Sea Basin, Israel, Based on New 230 Th/U dates
The Dead Sea is surrounded by chemical and detrital sediments that were deposited in its larger precursor lakes, Lake Samra and Lake Lisan. The sedimentary history of these lakes was recon-structed by means of 230 Th/ 234 U ages of 30 samples, mostly of argonite laminae, from 8 columnar sections up to 110 km apart. The general validity of the ages was demonstrated by subjecting them to tests of internal isotopic consistency, agreement with strati…
The Distribution of 230 Th/ 234 U Ages in Corals and the Number of Last Interglacial High-sea Stands
The 104 available [ 230 Th/ 234 U] analyses of unrecrystallized corals from stable emerged terraces indicate that the last interglacial period occurred approximately 125,000 yr ago. An estimate is made of the exact duration of this period by accounting for the surprisingly small distribution width observed among the 80 most reliable analyses. This distribution width is compared with those obtained for model populations generated by assuming vario…
The Effect of Atmospheric 14 C Variations on the 14 C Levels in the Jordan River System
13 C and 14 C were measured in the upper Jordan River, in its tributaries which issue from the Mount Hermon aquifer, and in the local atmospheric CO 2 to evaluate the degree to which changes in the atmospheric 14 C levels influence the 14 C levels in the aquifer and in the Jordan River. The exchange fraction of CO 2 between the river and the atmosphere was calculated for fall 1983 with the two carbon isotopes and it is shown that the value obtain…
Detection of the 36 Cl Radioisotope at the Rehovot 14UD Pelletron Accelerator
A program of accelerator mass spectrometry has been started at the Rehovot 14UD Pelletron Accelerator Laboratory. Part of the initial emphasis has been directed to the detection of the 36 Cl radioisotope. We report here on the present status of our work and describe our experimental system. Preliminary results are presented, showing that 36 Cl/Cl concentrations ranging down to 1×10 −14 could be measured with our system
The Climatic History of the Eastern Mediterranean as Recorded in Mollusk Shells
An 18 O/ 16 O versus 14 C age curve was constructed for unrecrystallized Holocene marine shell samples from Israel that were shown to be homogeneous populations. The surprisingly large variation in the oxygen isotopic composition (1.2‰) between 2600 and 4000 years ago is most probably due to variations in the isotopic composition of the water. This implies that either the excess of evaporation over precipitation or the Nile river discharge must h…
Calibration of Lacustrine Sediment Ages Using the Relationship Between 14 C Levels in Lake Waters and in the Atmosphere
The source of endogenic organic and inorganic carbon in lacustrine sediments is the dissolved inorganic carbon (DIC) in the lake water. The relation between the radiocarbon levels of DIC in Lake Kinneret and of CO 2 in the atmosphere has been investigated. The ratio of the former to the latter was found to be 0.814 ± 0.013. This ratio is used for calibrating the age of the sediment according to the natural fluctuations in the atmospheric levels o…
The Effect of Atmospheric 14 C Variations on the 14 C Levels in the Jordan River System
13 C and 14 C were measured in the upper Jordan River, in its tributaries which issue from the Mount Hermon aquifer, and in the local atmospheric CO 2 to evaluate the degree to which changes in the atmospheric 14 C levels influence the 14 C levels in the aquifer and in the Jordan River. The exchange fraction of CO 2 between the river and the atmosphere was calculated for fall 1983 with the two carbon isotopes and it is shown that the value obtain…
Petrography, strontium, barium and uranium concentrations, and strontium and uranium isotope ratios in speleothems as palaeoclimatic proxies
The reconstruction of the palaeoclimate of the eastern Mediterranean region for the last 60 ka BP is based on theδ 18 O andδ 13 C variations of speleothems from Soreq Cave, Israel. Climatic conditions during most of the time interval between 60 and 17 ka BP (the period equivalent to the last glacial) were relatively cold and dry, while they were warmer and wetter from 17 ka BP to the present. At ~17 ka BP, there was a major climatic change with a…
Spatial Variations of Radiocarbon in the Coastal Aquifer of Israel—Indicators of Open and Closed Systems
The spatial variation in radiocarbon concentration was studied in the Coastal Aquifer of Israel. Lower concentrations were found in the western section of the aquifer (55–70 pMC) as compared to the eastern section (80–100 pMC). Since no correlation was found between the tritium and radiocarbon values, these variations could not simply be explained by a difference in ages, or by a difference in the degree of old calcite dissolution as similar δ 13…
The Climatic History of the Eastern Mediterranean as Recorded in Mollusk Shells
An 18 O/ 16 O versus 14 C age curve was constructed for unrecrystallized Holocene marine shell samples from Israel that were shown to be homogeneous populations. The surprisingly large variation in the oxygen isotopic composition (1.2‰) between 2600 and 4000 years ago is most probably due to variations in the isotopic composition of the water. This implies that either the excess of evaporation over precipitation or the Nile river discharge must h…
Detection of the 36 Cl Radioisotope at the Rehovot 14UD Pelletron Accelerator
A program of accelerator mass spectrometry has been started at the Rehovot 14UD Pelletron Accelerator Laboratory. Part of the initial emphasis has been directed to the detection of the 36 Cl radioisotope. We report here on the present status of our work and describe our experimental system. Preliminary results are presented, showing that 36 Cl/Cl concentrations ranging down to 1×10 −14 could be measured with our system
The Effect of Atmospheric 14 C Variations on the 14 C Levels in the Jordan River System
13 C and 14 C were measured in the upper Jordan River, in its tributaries which issue from the Mount Hermon aquifer, and in the local atmospheric CO 2 to evaluate the degree to which changes in the atmospheric 14 C levels influence the 14 C levels in the aquifer and in the Jordan River. The exchange fraction of CO 2 between the river and the atmosphere was calculated for fall 1983 with the two carbon isotopes and it is shown that the value obtain…
The Distribution of 230 Th/ 234 U Ages in Corals and the Number of Last Interglacial High-sea Stands
The 104 available [ 230 Th/ 234 U] analyses of unrecrystallized corals from stable emerged terraces indicate that the last interglacial period occurred approximately 125,000 yr ago. An estimate is made of the exact duration of this period by accounting for the surprisingly small distribution width observed among the 80 most reliable analyses. This distribution width is compared with those obtained for model populations generated by assuming vario…
Reevaluation of the Lake-Sediment Chronology in the Dead Sea Basin, Israel, Based on New 230 Th/U dates
The Dead Sea is surrounded by chemical and detrital sediments that were deposited in its larger precursor lakes, Lake Samra and Lake Lisan. The sedimentary history of these lakes was recon-structed by means of 230 Th/ 234 U ages of 30 samples, mostly of argonite laminae, from 8 columnar sections up to 110 km apart. The general validity of the ages was demonstrated by subjecting them to tests of internal isotopic consistency, agreement with strati…
Late Quaternary Paleoclimate in the Eastern Mediterranean Region from Stable Isotope Analysis of Speleothems at Soreq Cave, Israel
The eastern Mediterranean continental paleoclimate during the past 25,000 years was determined by a high-resolution petrographic, stable isotopic, and age study of speleothems from Soreq Cave, Israel. δ 18 O–δ 13 C trends indicate that all speleothems older than 7000 yr formed under conditions that differ from those of today. The period from 25,000 to 17,000 yr B.P. was characterized by the highest δ 18 O and δ 13 C values, which indicate deposit…
The Eastern Mediterranean paleoclimate as a reflection of regional events
Petrography, strontium, barium and uranium concentrations, and strontium and uranium isotope ratios in speleothems as palaeoclimatic proxies
The reconstruction of the palaeoclimate of the eastern Mediterranean region for the last 60 ka BP is based on theδ 18 O andδ 13 C variations of speleothems from Soreq Cave, Israel. Climatic conditions during most of the time interval between 60 and 17 ka BP (the period equivalent to the last glacial) were relatively cold and dry, while they were warmer and wetter from 17 ka BP to the present. At ~17 ka BP, there was a major climatic change with a…
Spatial Variations of Radiocarbon in the Coastal Aquifer of Israel—Indicators of Open and Closed Systems
The spatial variation in radiocarbon concentration was studied in the Coastal Aquifer of Israel. Lower concentrations were found in the western section of the aquifer (55–70 pMC) as compared to the eastern section (80–100 pMC). Since no correlation was found between the tritium and radiocarbon values, these variations could not simply be explained by a difference in ages, or by a difference in the degree of old calcite dissolution as similar δ 13…
Calibration of Lacustrine Sediment Ages Using the Relationship Between 14 C Levels in Lake Waters and in the Atmosphere
The source of endogenic organic and inorganic carbon in lacustrine sediments is the dissolved inorganic carbon (DIC) in the lake water. The relation between the radiocarbon levels of DIC in Lake Kinneret and of CO 2 in the atmosphere has been investigated. The ratio of the former to the latter was found to be 0.814 ± 0.013. This ratio is used for calibrating the age of the sediment according to the natural fluctuations in the atmospheric levels o…
Paleoclimate reconstruction based on the timing of speleothem growth and oxygen and carbon isotope composition in a cave located in the rain shadow in Israel
High-resolution 230 Th/ 234 U ages and δ 18 O and δ 13 C compositions of speleothems in Ma’ale Efrayim Cave located to the east of the central mountain ridge of Israel enable us to examine the nature of the rain shadow aridity during glacial and interglacial intervals. Speleothem growth occurred during marine glacial isotopic periods, with no growth during the two last marine isotope interglacial intervals and during the peak of the Last Glacial …
Geology and Paleoclimatology Research (9 obras) · Geography (7 obras) · Archaeology (6 obras) · Karst Systems and Hydrogeology (6 obras) · Geology (5 obras) · Geology (5 obras) · Holocene (5 obras) · Oceanography (5 obras) · Paleontology (5 obras) · Physical geography (5 obras)