scholarly journals Accelerator Mass Spectrometry at Arizona: Geochronology of the Climatic Record and Connections with the Ocean

2002 ◽  
Vol 2 ◽  
pp. 1579-1593 ◽  
Author(s):  
J.T. Jull ◽  
G.S. Burr ◽  
J.W. Beck ◽  
D.J. Donahue ◽  
D. Biddulph ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Radioactive Waste ◽  
Environmental Conditions ◽  
Accelerator Mass Spectrometry ◽  
Time Scale ◽  
Southern Oscillation ◽  
Waste Dump ◽  
Short Term ◽  
Millennial Time Scale ◽  
Climatic Record

There are many diverse uses of accelerator mass spectrometry (AMS).14C studies at our laboratory include much research related to paleoclimate, with14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments, and many terrestrial records. Terrestrial records can also show the influence of oceanic oscillations, whether they are short term, such as ENSO (El Niño/Southern Oscillation), or on the millennial time scale. In tracer applications, we have developed the use of129I as well as14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson, AZ, for several of these fields and hope to give some idea of the breadth of these studies.

Misunderstandings Concerning the Significance of AMS Background 14C Measurements

Radiocarbon ◽  
2018 ◽  
Vol 60 (3) ◽  
pp. 727-749
Author(s):  
R E Taylor ◽  
John R Southon ◽  
Guaciara M Santos
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Time Scale ◽  
Point Of View ◽  
General Validity ◽  
General Audience ◽  
Background Levels ◽  
Age Determinations

ABSTRACTWe consider one misconception of those who currently reject the general validity of radiocarbon (14C) age determinations older than, at most, 10,000 BP. There is an allegation that the presence of 14C reported by accelerator mass spectrometry (AMS) laboratories in their measurements of 14C infinite age (>100,000 years) organics used to define background levels, support their point of view. This article has been written for a general audience, primarily for those who have questions about the validity of these arguments. However, they may not be familiar with the literature relevant to providing a clear response to the claims of these individuals. We conclude that, in our view, of all of the possible explanations for the reports of the presence of 14C in these background samples, the least probable explanation has been advanced by those rejecting the validity of the 14C time scale in excess of, at most, 10,000 BP.

scholarly journals Radiocarbon in 9th to 5th Century BC Tree-Ring Samples from the Ouban 1 Archaeological Site, Hiroshima, Japan

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 473-479 ◽  
Author(s):  
Hiromasa Ozaki ◽  
Mineo Imamura ◽  
Hiroyuki Matsuzaki ◽  
Takumi Mitsutani
Keyword(s):  
Mass Spectrometry ◽  
Tree Ring ◽  
Calibration Curve ◽  
Accelerator Mass Spectrometry ◽  
Wood Sample ◽  
Archaeological Site ◽  
Short Term ◽  
Statistical Errors ◽  
Term Fluctuation

In order to investigate the regional atmospheric radiocarbon offset, accelerator mass spectrometry (AMS) 14C measurements were made on 5-yr increments of a Japanese wood sample dendrochronologically dated to 820–436 BC. The 14C data from the Japanese tree-ring samples were compared with the IntCal04 calibration curve (Reimer et al. 2004). In most parts, the differences between IntCal04 and 14C dates in the Japanese tree-ring samples were within experimental statistical errors. At around 680 BC, however, significant differences of up to 100 14C yr were observed. These differences may indicate either regional offsets in Japan or the short-term fluctuation of a subdecadal timescale in atmospheric 14C variations.

AMS Measurement of 59Ni at China Institute of Atomic Energy

Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 302-307 ◽  
Author(s):  
Ming He ◽  
Xiangdong Ruan ◽  
Wei Wang ◽  
Liang Dou ◽  
Lingbo Xie ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Radioactive Waste ◽  
Waste Management ◽  
Accelerator Mass Spectrometry ◽  
Detection System ◽  
Atomic Energy ◽  
Detection Sensitivity ◽  
Research Fields ◽  
Laboratory Reference ◽  
Reference Samples

The long-lived radioisotope 59Ni is of interest in various research fields including neutron dosimetry, radioactive waste management, and astrophysics. In order to achieve the sensitivity required for such applications, the technique of accelerator mass spectrometry (AMS) 59Ni measurement has been developed at the AMS facility at China Institute of Atomic Energy (CIAE). Based on the AE-Q3D detection system in the CIAE AMS facility, the interference in 59Ni counting from the isobar 59Co has been reduced by a factor of 8 × 106. A series of laboratory reference samples and a blank sample were measured to check the performance of 59Ni measurement. A detection sensitivity of about 5 × 10−13 (59Ni/Ni) has been obtained.

scholarly journals Hubungan Indeks Osilasi Selatan dan Indeks Curah Hujan terhadap Kejadian Kekeringan di Kabupaten Indramayu, Jawa Barat, Indonesia

2017 ◽  
Vol 1 (1) ◽  
pp. 64
Author(s):  
BOEDI TJAHJONO ◽  
BABA BARUS ◽  
NINA WIDIANA DAROJATI
Keyword(s):  
Time Scale ◽  
Southern Oscillation ◽  
Research Area ◽  
Extreme Drought ◽  
Drought Indices ◽  
Short Term ◽  
Drought Period ◽  
Strong Relation

Indramayu district experiences frequent droughts that leads to many paddy fields harvest failure. Since the district is one of the national granary, this disaster needs to be addressed urgently. This study aimed to assess the level of dryness in Indramayu using Standard Precipitation Index (SPI) and its relation with the Southern Oscillation Index (SOI). The study used monthly rainfall data from 1996 to 2013 observed by 19 stations and the score of SOI that came from the Bureau of Meteorology of Australia. The method used quantitative approach using SPI and software SPI_sl_6.exe. Drought indices was measured in four different time scale which are 1, 3, and 6 month(s) (for the short term period) and the 12 months time scale (for the long term period). SPI’s assessment was classified in accordance with the classification of WMO (World Meteorological Organization) which consist of seven classes, ranging from wet extreme to dry extreme class. The results showed that the occurence of "very dry" to "dry extreme“ drought was occured mainly from February 1997 to January 1998 at most stations, while for some stations, it lasted until March 1998. The drought period was lasted from nine to ten months. In 2002 to 2003, the droughts that classified as "very dry" on a 3 and 6 months time scale lasted about five months, while the 12 months time scale was lasted about nine months. SPI value that obtained from different time scales has a strong relation with the value of SOI. The negative value of SOI tends to be followed by the negative value of SPI, and vice versa. SOI that has negative value below -7 and occured in a long period (more than three months) indicates a prolonged El Nino which occurred in 1997 and 2002/2003 when the research area was struck by "being dry" to "dry extreme" drought state.

scholarly journals AMS Radiocarbon Measurements from the Swedish Varved Clays

Radiocarbon ◽  
2000 ◽  
Vol 42 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Barbara Wohlfarth ◽  
Göran Possnert
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Time Scale ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Northern Sweden ◽  
The Baltic Sea ◽  
Varve Chronology ◽  
Scandinavian Ice Sheet ◽  
The Baltic

The Swedish varve chronology, or Swedish Time Scale, is an annual chronology based upon the successive correlation of more than 1000 varve-thickness diagrams. The Late Glacial-Early Holocene varved clays were deposited as glaciolacustrine sediments in the Baltic Sea during the recession of the Scandinavian ice sheet. Formation of varved clays continued throughout the Holocene and is still going on in the estuary of River ångermanälven in northern Sweden. Accelerator mass spectrometry (AMS) radiocarbon measurements, which have been performed on terrestrial plant macrofossils extracted from the varved clays, show—in comparison with other annual chronologies—that several hundreds of varve years are missing in the varve chronology. These findings are supported by, among others, pollen stratigraphic investigations on time-equivalent varve year intervals. If an effort were undertaken to evaluate the erroneous parts, the Swedish Time Scale would have the potential of becoming a continuous annual chronology.

scholarly journals Hiatus in Prehistoric Chronology of the Cis-Baikal Region, Siberia: Pattern or Artifact?

Radiocarbon ◽  
2007 ◽  
Vol 49 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Yaroslav V Kuzmin
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Baikal Region ◽  
Critical Evaluation ◽  
Burial Grounds

The problem of a hiatus at about 6100–5300 BP (about 4900–4200 cal BC) in the prehistoric chronology of the Cis-Baikal region in Siberia is discussed. Based on a critical evaluation of existing evidence, there was no discontinuity found in the cultural sequence between the Kitoi and Serovo/Glazkovo complexes of the Neolithic, and the proposed “hiatus” may be an artifact based on underestimation of solid data. Conventional 14C dates are presented that were generated in the 1980s to early 2000s for Cis-Baikal prehistoric burial grounds, and were later dated by the accelerator mass spectrometry (AMS).

scholarly journals 14C INTERCOMPARISON EXERCISE ON BONES AND IVORY SAMPLES: IMPLICATIONS FOR FORENSICS

Radiocarbon ◽  
2021 ◽  
pp. 1-12
Author(s):  
G Quarta ◽  
M Molnár ◽  
I Hajdas ◽  
L Calcagnile ◽  
I Major ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
International Atomic Energy Agency ◽  
Accelerator Mass Spectrometry ◽  
Reference Curve ◽  
Nuclear Testing ◽  
Energy Agency ◽  
Widespread Application ◽  
Intercomparison Exercise ◽  
High Degree ◽  
Data Calibration

ABSTRACT The application of accelerator mass spectrometry radiocarbon (AMS 14C) dating in forensics is made possible by the use of the large excursion of the 14C concentration in the post-WWII terrestrial atmosphere due to nuclear testing as a reference curve for data calibration. By this approach high-precision analyses are possible on samples younger than ∼70 years. Nevertheless, the routine, widespread application of the method in the practice of forensics still appears to be limited by different issues due to possible complex interpretation of the results. We present the results of an intercomparison exercise carried out in the framework of an International Atomic Energy Agency (IAEA) CRP-Coordinated Research Project between three AMS laboratories in Italy, Hungary, and Switzerland. Bone and ivory samples were selected with ages spanning from background (>50 ka) to 2018. The results obtained allow us to assess the high degree of reproducibility of the results and the remarkable consistency of the experimental determinations.

scholarly journals Dating of Cremated Bones

Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 249-254 ◽  
Author(s):  
J N Lanting ◽  
A T Aerts-Bijma ◽  
J van der Plicht
Keyword(s):  
Mass Spectrometry ◽  
Success Rate ◽  
Accelerator Mass Spectrometry ◽  
Bone Collagen ◽  
Organic Fraction ◽  
Mineral Fraction

When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a remarkable success rate for this method.

scholarly journals THE BEGINNING OF THE IRON AGE AT ARSLANTEPE: A 14C PERSPECTIVE

Radiocarbon ◽  
2021 ◽  
pp. 1-19
Author(s):  
Federico Manuelli ◽  
Cristiano Vignola ◽  
Fabio Marzaioli ◽  
Isabella Passariello ◽  
Filippo Terrasi
Keyword(s):  
Mass Spectrometry ◽  
Bronze Age ◽  
High Precision ◽  
Iron Age ◽  
Accelerator Mass Spectrometry ◽  
Late Bronze Age ◽  
13Th Century ◽  
Historical Events ◽  
Preliminary Results ◽  
Archaeological Data

ABSTRACT The Iron Age chronology at Arslantepe is the result of the interpretation of Luwian hieroglyphic inscriptions and archaeological data coming from the site and its surrounding region. A new round of investigations of the Iron Age levels has been conducted at the site over the last 10 years. Preliminary results allowed the combination of the archaeological sequence with the historical events that extended from the collapse of the Late Bronze Age empires to the formation and development of the new Iron Age kingdoms. The integration into this picture of a new set of radiocarbon (14C) dates is aimed at establishing a more solid local chronology. High precision 14C dating by accelerator mass spectrometry (AMS) and its correlation with archaeobotanical analysis and stratigraphic data are presented here with the purpose of improving our knowledge of the site’s history and to build a reliable absolute chronology of the Iron Age. The results show that the earliest level of the sequence dates to ca. the mid-13th century BC, implying that the site started developing a new set of relationships with the Levant already before the breakdown of the Hittite empire, entailing important historical implications for the Syro-Anatolian region at the end of the 2nd millennium BC.

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