A reevaluation of the Pallett Creek earthquake chronology based on new AMS radiocarbon dates, San Andreas fault, California

NASA Astrophysics Data System (ADS)

Scharer, Katherine M.; Biasi, Glenn P.; Weldon, Ray J., II

2011-12-01

The Pallett Creek paleoseismic record occupies a keystone position in most attempts to develop rupture histories for the southern San Andreas fault. Previous estimates of earthquake ages at Pallett Creek were determined by decay counting radiocarbon methods. That method requires large samples which can lead to unaccounted sources of uncertainty in radiocarbon ages because of the heterogeneous composition of organic layers. In contrast, accelerator mass spectrometry (AMS) radiocarbon dates may be obtained from small samples that have known carbon sources and also allow for a more complete sampling of the section. We present 65 new AMS radiocarbon dates that span nine ground-rupturing earthquakes at Pallett Creek. Overall, the AMS dates are similar to and reveal no dramatic bias in the conventional dates. For many layers, however, individual charcoal samples were younger than the conventional dates, leading to earthquake ages that are overall slightly younger than previously reported. New earthquake ages are determined by Bayesian refinement of the layer ages based on stratigraphic ordering and sedimentological constraints. The new chronology is more regular than previously published records in large part due to new samples constraining the age of event R. The closed interval from event C to 1857 has a mean recurrence of 135 years (σ = 83.2 years) and a quasiperiodic coefficient of variation (COV) of 0.61. We show that the new dates and resultant earthquake chronology have a stronger effect on COV than the specific membership of this long series and dating precision improvements from sedimentation rates.

Estimates of upwelling rates in the Arabian Sea and the equatorial Indian Ocean based on bomb radiocarbon.

PubMed

Bhushan, R; Dutta, K; Somayajulu, B L K

2008-10-01

Radiocarbon measurements were made in the water column of the Arabian Sea and the equatorial Indian Ocean during 1994, 1995 and 1997 to assess the temporal variations in bomb 14C distribution and its inventory in the region with respect to GEOSECS measurements made during 1977-1978. Four GEOSECS stations were reoccupied (three in the Arabian Sea and one in the equatorial Indian Ocean) during this study, with all of them showing increased penetration of bomb 14C along with decrease in its surface water activity. The upwelling rates derived by model simulation of bomb 14C depth profile using the calculated exchange rates ranged from 3 to 9 m a(-1). The western region of the Arabian Sea experiencing high wind-induced upwelling has higher estimated upwelling rates. However, lower upwelling rates obtained for the stations occupied during this study could be due to reduced 14C gradient compared to that during GEOSECS.

Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology

NASA Astrophysics Data System (ADS)

Uno, Kevin T.; Quade, Jay; Fisher, Daniel C.; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E.

2013-07-01

Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon (14C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric 14C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3-1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. 14C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. 14C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve 14C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts.

Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology.

PubMed

Uno, Kevin T; Quade, Jay; Fisher, Daniel C; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E

2013-07-16

Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon ((14)C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric (14)C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3-1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. (14)C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. (14)C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve (14)C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts.

Radiocarbon dating of individual lignin phenols: a new approach for establishing chronology of late quaternary lake sediments.

PubMed

Hou, Juzhi; Huang, Yongsong; Brodsky, Corynn; Alexandre, Marcelo R; McNichol, Ann P; King, John W; Hu, Feng Sheng; Shen, Ji

2010-09-01

The reliability of chronology is a prerequisite for meaningful paleoclimate reconstructions from sedimentary archives. The conventional approach of radiocarbon dating bulk organic carbon in lake sediments is often hampered by the old carbon effect, i.e., the assimilation of ancient dissolved inorganic carbon (DIC) derived from carbonate bedrocks or other sources. Therefore, radiocarbon dating is ideally performed on organic compounds derived from land plants that use atmospheric CO(2) and rapidly delivered to sediments. We demonstrate that lignin phenols isolated from lake sediments using reversed phase high performance liquid chromatography (HPLC) can serve as effective (14)C dating materials for establishing chronology during the late Quaternary. We developed a procedure to purify lignin phenols, building upon a published method. By isolating lignin from standard wood reference substances, we show that our method yields pure lignin phenols and consistent ages as the consensus ages and that our procedure does not introduce radiocarbon contamination. We further demonstrate that lignin phenol ages are compatible with varve counted and macrofossil dated sediment horizons in Steel Lake and Fayetteville Green Lake. Applying the new method to lake sediment cores from Lake Qinghai demonstrates that lignin phenol ages in Lake Qinghai are consistently younger than bulk total organic carbon (TOC) ages which are contaminated by old carbon effect. We also show that the age offset between lignin and bulk organic carbon differs at different Lake Qinghai sedimentary horizons, suggesting a variable hard water effect at different times and that a uniform age correction throughout the core is inappropriate.

Radiocarbon dating of open systems with bomb effect

NASA Technical Reports Server (NTRS)

Mckay, C. P.; Long, A.; Friedmann, E. I.

1986-01-01

The application of radiocarbon dating is extended to include systems that are slowly exchanging carbon with the atmosphere. Simple formulae are derived that relate the true age and the exchange rate of carbon to the apparent radiocarbon age. A radiocarbon age determination does not give a unique true age and exchange rate but determines a locus of values bounded by a minimum age and a minimum exchange rate. It is found that for radiocarbon ages as large as 10,000 years it is necessary to correct for the anthropogenic radiocarbon produced in the atmosphere by nuclear weapons testing. A one-term exponential approximation, with an e-folding time of 14.43 years, is used to model this effect and is shown to be accurate to within 3 percent for exchange time constants of 100 years and greater. The approach developed here is not specific to radiocarbon and can be applied to other radioisotopes in open systems.

Willard Libby, Radiocarbon, and Carbon Dating

Science.gov Websites

: Radiocarbon from Pile Graphite; Chemical Methods for Its Concentrations, DOE Technical Report Download Adobe Carbon Dating Chronological Methods 8 - Radiocarbon Dating, University of California, Santa Barbara Why

Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology

PubMed Central

Uno, Kevin T.; Quade, Jay; Fisher, Daniel C.; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E.

2013-01-01

Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon (14C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric 14C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3–1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. 14C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. 14C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve 14C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts. PMID:23818577

An absolute chronology for early Egypt using radiocarbon dating and Bayesian statistical modelling

PubMed Central

Dee, Michael; Wengrow, David; Shortland, Andrew; Stevenson, Alice; Brock, Fiona; Girdland Flink, Linus; Bronk Ramsey, Christopher

2013-01-01

The Egyptian state was formed prior to the existence of verifiable historical records. Conventional dates for its formation are based on the relative ordering of artefacts. This approach is no longer considered sufficient for cogent historical analysis. Here, we produce an absolute chronology for Early Egypt by combining radiocarbon and archaeological evidence within a Bayesian paradigm. Our data cover the full trajectory of Egyptian state formation and indicate that the process occurred more rapidly than previously thought. We provide a timeline for the First Dynasty of Egypt of generational-scale resolution that concurs with prevailing archaeological analysis and produce a chronometric date for the foundation of Egypt that distinguishes between historical estimates. PMID:24204188

Effect of anthropogenic activities on atmospheric 14C content and radiocarbon chronologies of the future.

NASA Astrophysics Data System (ADS)

Hajdas, Irka

2017-04-01

Radiocarbon (14C) is a naturally produced radioactive isotope of carbon (T1/2=5700 yrs), which is continuously produced in the atmosphere. This occur in a reaction of thermal neutrons, which are secondary particles, products of cosmic rays reactions with the atmosphere, with nitrogen that is commonly present in the atmosphere. Until the mid 19th century the natural concentration showed temporal variability around the mean value (14C / 12C ratio =1.8 x 10-12). However anthropogenic activity created 2 types effects that are changing the 14C concentration of the atmosphere. Industrial revolution triggered adding 14C free (old) carbon that originates from the burning of fossil fuels (Suess effect). This in the late 19th century and early 20th century atmosphere was becoming older. The nuclear tests in the 1950ties caused additional production of radiocarbon atoms (artificial). The effect has been almost double of the natural production and created an excess 14C activity in the atmosphere and in terrestrial carbon bearing materials. The bomb produced 14C has been identified soon after the tests started but the peak (ca. 100% above the normal levels) reached its maximum in 1963 in the northern Hemisphere where most of the tests took place. In the southern Hemisphere the bomb peak reached lower values (ca. 80 % of normal level) and was delayed by ca. 2 years. After the ban on nuclear tests the atmospheric 14C content began to decrease mainly due to the uptake by the ocean but also due to the above mentioned addition old carbon. Continuous monitoring of the atmospheric 14C ratio during the years that followed the nuclear tests, provide basis for environmental studies. Applications range from studies of ocean circulation, CO2 uptake, carbon storage in soils and peat, root turn over time to the medical, forensic and detection of forgeries. However, the so called ' 14C bomb peak' nearly disappeared due to the combined effect of ocean uptake of CO2 and an input to the

Nuclear Bombs and Coral: Guam Coral Core Reveals Operation-Specific Radiocarbon Signals from the Pacific Proving Grounds

NASA Astrophysics Data System (ADS)

Andrews, A. H.

2016-12-01

Radiocarbon (14C) analyses on a coral core extracted from the western Central Pacific (Guam) has revealed a series of early peaks in the marine bomb 14C record. The typical marine bomb 14C signal, one that is phase lagged and attenuated relative to atmospheric bomb 14C, is present in the coral core and is consistent with other North Pacific records. However, 14C levels that are well above what can be explained by air-sea diffusion alone punctuate this pattern. This anomaly has been demonstrated to a limited extent in other coral cores of the Indo-Pacific region, but is unmatched relative to the magnitude and temporal resolution recorded in the Guam coral core. Other records have shown an early Δ14C rise on the order of 40-50‰ above pre-bomb levels, with a subsequent decline before continuing the gradual Δ14C rise that is indicative of air-sea diffusion of 14CO2. The Guam coral Δ14C record provided three strong pulses in 1954-55, 1956-57, and 1958-59 that are superimposed on the pre-bomb to initial Δ14C rise from atmospheric bomb 14C. Each of these peaks can be directly linked to testing of thermonuclear devices in the Pacific Proving Grounds at Eniwetok and Bikini Atoll of the Marshall Islands. The measurable lag in reaching Guam can be tied to ocean surface currents and can be traced to other regional Δ14C records from corals, providing a transport timeline to places as distant as the Indonesian throughflow, Okinawa and Palmyra.

Radiocarbon dating casts doubt on the late chronology of the Middle to Upper Palaeolithic transition in southern Iberia.

PubMed

Wood, Rachel E; Barroso-Ruíz, Cecilio; Caparrós, Miguel; Jordá Pardo, Jesús F; Galván Santos, Bertila; Higham, Thomas F G

2013-02-19

It is commonly accepted that some of the latest dates for Neanderthal fossils and Mousterian industries are found south of the Ebro valley in Iberia at ca. 36 ka calBP (calibrated radiocarbon date ranges). In contrast, to the north of the valley the Mousterian disappears shortly before the Proto-Aurignacian appears at ca. 42 ka calBP. The latter is most likely produced by anatomically modern humans. However, two-thirds of dates from the south are radiocarbon dates, a technique that is particularly sensitive to carbon contaminants of a younger age that can be difficult to remove using routine pretreatment protocols. We have attempted to test the reliability of chronologies of 11 southern Iberian Middle and early Upper Paleolithic sites. Only two, Jarama VI and Zafarraya, were found to contain material that could be reliably dated. In both sites, Middle Paleolithic contexts were previously dated by radiocarbon to less than 42 ka calBP. Using ultrafiltration to purify faunal bone collagen before radiocarbon dating, we obtain ages at least 10 ka (14)C years older, close to or beyond the limit of the radiocarbon method for the Mousterian at Jarama VI and Neanderthal fossils at Zafarraya. Unless rigorous pretreatment protocols have been used, radiocarbon dates should be assumed to be inaccurate until proven otherwise in this region. Evidence for the late survival of Neanderthals in southern Iberia is limited to one possible site, Cueva Antón, and alternative models of human occupation of the region should be considered.

Radiocarbon dating casts doubt on the late chronology of the Middle to Upper Palaeolithic transition in southern Iberia

PubMed Central

Wood, Rachel E.; Barroso-Ruíz, Cecilio; Caparrós, Miguel; Jordá Pardo, Jesús F.; Galván Santos, Bertila; Higham, Thomas F. G.

2013-01-01

It is commonly accepted that some of the latest dates for Neanderthal fossils and Mousterian industries are found south of the Ebro valley in Iberia at ca. 36 ka calBP (calibrated radiocarbon date ranges). In contrast, to the north of the valley the Mousterian disappears shortly before the Proto-Aurignacian appears at ca. 42 ka calBP. The latter is most likely produced by anatomically modern humans. However, two-thirds of dates from the south are radiocarbon dates, a technique that is particularly sensitive to carbon contaminants of a younger age that can be difficult to remove using routine pretreatment protocols. We have attempted to test the reliability of chronologies of 11 southern Iberian Middle and early Upper Paleolithic sites. Only two, Jarama VI and Zafarraya, were found to contain material that could be reliably dated. In both sites, Middle Paleolithic contexts were previously dated by radiocarbon to less than 42 ka calBP. Using ultrafiltration to purify faunal bone collagen before radiocarbon dating, we obtain ages at least 10 ka 14C years older, close to or beyond the limit of the radiocarbon method for the Mousterian at Jarama VI and Neanderthal fossils at Zafarraya. Unless rigorous pretreatment protocols have been used, radiocarbon dates should be assumed to be inaccurate until proven otherwise in this region. Evidence for the late survival of Neanderthals in southern Iberia is limited to one possible site, Cueva Antón, and alternative models of human occupation of the region should be considered. PMID:23382220

A coherent high-precision radiocarbon chronology for the Late-glacial sequence at Sluggan Bog, Co. Antrim, Northern Ireland

NASA Astrophysics Data System (ADS)

Lowe, J. J.; Walker, M. J. C.; Scott, E. M.; Harkness, D. D.; Bryant, C. L.; Davies, S. M.

2004-02-01

Seventy-five radiocarbon dates are presented from Sluggan Bog in Co. Antrim, Northern Ireland. The Holocene peats are underlain by Late-glacial sediments, which also appear to have accumulated largely in a mire environment. The radiocarbon dates, from the Late-glacial and early Holocene part of the profile, were obtained from the humic and humin fractions of the sedimentary matrix, and from plant macrofossils. The last-named were dated by AMS and the sediment samples by radiometric (beta counting) methods. Age-depth models for the three dating series show a very high level of agreement between the two fractions and the macrofossils. No statistically significant difference is found between the beta counting and AMS results. Three tephras were located in the profile, the uppermost of which is in a stratigraphical position suggestive of the Vedde Ash, but the geochemical and radiocarbon evidence do not support this interpretation. The lower ashes are in the correct stratigraphical position for the Laacher See and Borrobol tephras, attributions substantiated by the radiocarbon evidence, but not by the geochemical data. The Sluggan sequence has generated one of the most internally consistent radiocarbon chronologies for any Late-glacial site in the British Isles, and it is suggested that in future more effort should be devoted to the search for, and analysis of, Late-glacial mire sequences, rather than the limnic records that have formed the principal focus of Late-glacial investigations hitherto. Copyright

Radiocarbon and stable isotopes in Palmyra corals during the past century

NASA Astrophysics Data System (ADS)

Druffel-Rodriguez, Kevin C.; Vetter, Desiree; Griffin, Sheila; Druffel, Ellen R. M.; Dunbar, Robert B.; Mucciarone, David A.; Ziolkowski, Lori A.; Sanchez-Cabeza, Joan-Albert

2012-04-01

Annual samples from two Palmyra Atoll corals (Porites lutea) that lived during the past 110 years were analyzed for radiocarbon (Δ14C) and δ18O. The Δ14C values decreased 7.6‰ from 1896 to 1953, similar to other coral records from the tropical and subtropical Pacific. Δ14C values rose from ˜-60‰ to ˜+110‰ by 1980 due to the input of bomb radiocarbon from the atmosphere. Elevated Δ14C values were observed for the mid- to late-1950s, suggesting early input of bomb radiocarbon, possibly from the largest Marshall Islands bomb tests in 1954. Secondary aragonite precipitation was identified in a portion of one core using scanning electron microscopy and X-radiography, and was responsible for high δ18O and δ13C values and a correlation between them. The Δ14C results were more resistant to alteration, except when contamination was from the bomb era (>1956).

Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology.

PubMed

Manning, Sturt W; Griggs, Carol B; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

2016-01-01

500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681-1673 BCE (68.2% highest posterior density range), ~20

Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology

PubMed Central

Griggs, Carol B.; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

2016-01-01

500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681–1673 BCE (68.2% highest posterior density range), ~20

Radiocarbon evidence for a smaller oceanic carbon dioxide sink than previously believed

NASA Astrophysics Data System (ADS)

Hesshaimer, Vago; Heimann, Martin; Levin, Ingeborg

1994-07-01

RADIOCARBON produced naturally in the upper atmosphere or arti-ficially during nuclear weapons testing is the main tracer used to validate models of oceanic carbon cycling, in particular the exchange of carbon dioxide with the atmosphere1-3 and the mixing parameters within the ocean itself4-7. Here we test the overall consistency of exchange fluxes between all relevant compartments in a simple model of the global carbon cycle, using measurements of the long-term tropospheric CO2 concentration8 and radiocarbon composition9-12, the bomb 14C inventory in the stratosphere13,14 and a compilation of bomb detonation dates and strengths15. We find that to balance the budget, we must invoke an extra source to account for 25% of the generally accepted uptake of bomb 14C by the oceans3. The strength of this source decreases from 1970 onwards, with a characteristic timescale similar to that of the ocean uptake. Significant radiocarbon transport from the remote high stratosphere and significantly reduced uptake of bomb 14C by the biosphere can both be ruled out by observational constraints. We therefore conclude that the global oceanic bomb 14C inventory should be revised downwards. A smaller oceanic bomb 14C inventory also implies a smaller oceanic radiocarbon penetration depth16, which in turn implies that the oceans take up 25% less anthropogenic CO2 than had previously been believed.

Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ubelaker, D H; Buchholz, B A; Stewart, J

Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth crowns provides information about the date of formation in the childhood years and in consideration of the known timing of tooth formation can be used to estimate the birth date after 1950 A.D. Radiocarbon analysis of modern cortical and trabecularmore » bone samples from the same skeleton may allow proper placement on the pre-1963 or post-1963 sides of the bomb-curve since most trabecular bone generally undergoes more rapid remodeling than does most cortical bone. Pre-1963 bone formation would produce higher radiocarbon values for most trabecular bone than for most cortical bone. This relationship is reversed for formation after 1963. Radiocarbon analysis was conducted in this study on dental, cortical and trabecular bone samples from two adult individuals of known birth (1925 and 1926) and death dates (1995 and 1959). As expected, the dental results correspond to pre-bomb bomb-curve values reflecting conditions during the childhoods of the individuals. The curve radiocarbon content of most bone samples reflected the higher modern bomb-curve values. Within the bone sample analyses, the values of the trabecular bone were higher than those of cortical bone and supported the known placement on the pre-1963 side of the bomb-curve.« less

Late Holocene Radiocarbon Variability in Northwest Atlantic Slope Waters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sherwood, O; Edinger, E; Guilderson, T P

2008-08-15

Deep-sea gorgonian corals secrete a 2-part skeleton of calcite, derived from dissolved inorganic carbon at depth, and gorgonin, derived from recently fixed and exported particulate organic matter. Radiocarbon contents of the calcite and gorgonin provide direct measures of seawater radiocarbon at depth and in the overlying surface waters, respectively. Using specimens collected from Northwest Atlantic slope waters, we generated radiocarbon records for surface and upper intermediate water layers spanning the pre- and post bomb-{sup 14}C eras. In Labrador Slope Water (LSW), convective mixing homogenizes the pre-bomb {Delta}{sup 14}C signature (-67 {+-} 4{per_thousand}) to at least 1000 m depth. Surface watermore » bomb-{sup 14}C signals were lagged and damped (peaking at {approx} +45{per_thousand} in the early 1980s) relative to other regions of the northwest Atlantic, and intermediate water signals were damped further. Off southwest Nova Scotia, the vertical gradient in {Delta}{sup 14}C is much stronger. In surface water, pre-bomb {Delta}{sup 14}C averaged -75 {+-} 5{per_thousand}. At 250-475 m depth, prebomb {Delta}{sup 14}C oscillated quasi-decadally between -80 and -100{per_thousand}, likely reflecting interannual variability in the presence of Labrador Slope Water vs. Warm Slope Water (WSW). Finally, subfossil corals reveal no systematic changes in vertical {Delta}{sup 14}C gradients over the last 1200 years.« less

Changes in the radiocarbon reservoir age in Lake Xingyun, Southwestern China during the Holocene.

PubMed

Zhou, Aifeng; He, Yuxin; Wu, Duo; Zhang, Xiaonan; Zhang, Can; Liu, Zhonghui; Yu, Junqing

2015-01-01

Chronology is a necessary component of paleoclimatology. Radiocarbon dating plays a central role in determining the ages of geological samples younger than ca. 50 ka BP. However, there are many limitations for its application, including radiocarbon reservoir effects, which may cause incorrect chronology in many lakes. Here we demonstrate temporal changes in the radiocarbon reservoir age of Lake Xingyun, Southwestern China, where radiocarbon ages based on bulk organic matter have been reported in previous studies. Our new radiocarbon ages, determined from terrestrial plant macrofossils suggest that the radiocarbon reservoir age changed from 960 to 2200 years during the last 8500 cal a BP years. These changes to the reservoir effect were associated with inputs from either pre-aged organic carbon or 14C-depleted hard water in Lake Xingyun caused by hydrological change in the lake system. The radiocarbon reservoir age may in return be a good indicator for the carbon source in lake ecosystems and depositional environment.

Radiocarbon dating of twentieth century works of art

NASA Astrophysics Data System (ADS)

Petrucci, F.; Caforio, L.; Fedi, M.; Mandò, P. A.; Peccenini, E.; Pellicori, V.; Rylands, P.; Schwartzbaum, P.; Taccetti, F.

2016-11-01

The atmospheric tests of nuclear weapons caused a sudden increase in the radiocarbon concentration in the atmosphere from 1955, reaching its maximum value in 1963-1965. Once the nuclear tests in the atmosphere were halted, the 14C concentration started to decrease. This behavior of the radiocarbon concentration is called the "Bomb Peak", and it has successfully been used as a tool for high-precision radiocarbon measurements, in forensic sciences and biology. In the art field, the possibility of dating canvas, wood and paper, widely used as supports for paintings, may be an invaluable tool in modern art studies.

Age validation and growth of bluenose Hyperoglyphe antarctica using the bomb chronometer method of radiocarbon ageing.

PubMed

Horn, P L; Neil, H L; Paul, L J; Marriott, P

2010-11-01

Age validation of bluenose Hyperoglyphe antarctica was sought using the independent bomb chronometer procedure. Radiocarbon ((14) C) levels were measured in core micro-samples from 12 otoliths that had been aged using a zone count method. The core (14) C measurement for each fish was compared with the value on a surface water reference curve for the calculated birth year of the fish. There was good agreement, indicating that the line-count ageing method described here is not substantially biased. A second micro-sample was also taken near the edge of nine of the otolith cross-sections to help define a bomb-carbon curve for waters deeper than 200-300 m. There appears to be a 10 to 15 year lag in the time it takes the (14) C to reach the waters where adult H. antarctica are concentrated. The maximum estimated age of this species was 76 years, and females grow significantly larger than males. Von Bertalanffy growth curves were estimated, and although they fit the available data reasonably well, the lack of aged juvenile fish results in the K and t(0) parameters being biologically meaningless. Consequently, curves that are likely to better represent population growth were estimated by forcing t(0) to be -0·5. © 2010 NIWA. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

The Varved Sediments of Lake Bosumtwi, Ghana and Implications for a new Chronology of West African Hydrologic Change During the Late Quaternary

NASA Astrophysics Data System (ADS)

Wheeler, C. W.; Overpeck, J. T.; Beck, J. W.; Arko, J.; Sharp, W. E.

2002-12-01

Lake Bosumtwi is a small (8-km diameter), deep (78-m) crater lake in the lowland forest of southern Ghana (West Africa) that offers tremendous potential for high-resolution environmental reconstruction. Lying in the path of the seasonal Intertropical Convergence Zone (ITCZ) monsoonal precipitation procession, as well as the dry Harmattan winds of the Sahel in winter, this lake is uniquely located to provide potential proxy records of these dominate climatic phenomena effecting West Africa's hydrologic cycle. The lake exhibits excellent sediment preservation, with finely laminated sediments through most of the ca. 24,000 years of core material recovered thus far. We present a detailed chronological analysis of the uppermost 1.1 meters of laminated sediment, obtained via a recently collected suite of freeze- and piston-cores. Utilizing digital images and petrographic thin-section transects of six freeze-cores and two piston cores, we identified 400 diagnostic marker laminations common among the cores, thus enabling cross correlation of the cores to a sub-centimeter scale. The marker laminations also serve as anchor points for counts of organic-rich fine-laminations that were hypothesized to be annual. Excellent agreement between our lamination counts and independent radiometric sediment age models (lead-210 and bomb radiocarbon) verify that these counted laminations are in fact annual (i.e. varves). Thus, we are able to present an annual chronology for the last 800 years of sedimentation (prior to 2000 AD)ñ ~4%. Though anthroprogenic changes have probably effected the local environment within the last 100 years, as we interpret anomalous increases in %organic carbon, %inorganic carbon and %nitrogen to indicate, the varve appearance does not seem to change across the 1.1 m section analyzed. Pre-nuclear weapon testing radiocarbon values, derived from bulk organic carbon, were examined in relation to the varve and lead-210 age-models to assess radiocarbon age offset

The nuclear bomb carbon curve recorded in tree-rings and lake sediments near Taal Volcano, Central Philippines

NASA Astrophysics Data System (ADS)

Liou, M. S.; Li, H. C.; Huang, S. K.; Guan, B. T.

2017-12-01

Dendrochronologies built from precisely dated annual rings have shown to record the regional bomb pulse and the C-14 concentration variations caused by local events. In this study, we collected teak trees Tectona grandis near the Lake Taal, Central Philippines in 2011 for dendrochronological analysis and radiocarbon dating. The tree-ring sample contains 90 rings dated from 1922 to 2011. Currently, 28 selected subsamples have been measured by AMS 14C on bulk carbon with a few samples on holocellulose. The 14C results of the samples indicate that: 1) the results of AMS 14C dating between holocellulose and whole wood from the same ring are similar, so we select whole wood for AMS 14C dating. 2) The nuclear bomb 14C pulse was clearly recorded in the Tectona grandis growth rings. The Δ14C values rose dramatically in 1960 and reached a maximum of 692‰ in 1966. The magnitude and the peak year of the bomb curve in the Tectona grandis tree-ring record are comparable to other published tree-ring records in the tropical regions. 3) The Δ14C values suddenly dropped in 1950, 1964 and 1968, probably affected by CO2 gas releasing due to the Taal volcanic activities. Further study on the tree-ring 14C dating will allow us to evaluate the bomb pulse trends more precisely, and the volcanic activities of Pinatubo and Taal Volcanoes. The tree-ring Δ14C record not only confirms existence of the bomb curve in Taal Lake area, but also allows us compare to the Δ14C record in the lake sediment for chronological construction. A 120-cm gravity core, TLS-2, collected from Lake Taal in 2008, shows the nuclear bomb carbon curve in the TOC of the core. However, the magnitude of the nuclear bomb 14C pulse in the TOC of TLS-2 is much lower than that in the tree-ring records, due to mixing effect of different organic carbon sources, smoothing effect of 14CO2 in multiple years plant growths, local old CO2 emission from volcanic activity, degassing from the lake bottom, and industrial and city

The feasibility of bomb radiocarbon analysis to support an age-at-length relationship for red abalone, Haliotis rufescens Swainson in northern California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leaf, R T; Andrews, A H; Cailliet, G M

2009-01-07

Analysis of bomb generated radiocarbon ({sup 14}C) changes in a red abalone, Haliotis rufescens Swainson shell was used to investigate age-at-length relationships derived from data from a previous multi-year, multi-site tag-recapture study. Shell carbonate was extracted from four successive growth trajectory locations in a single shell with a length of 251 mm MSL. Extraction locations were based on VBGF predictions and chosen to span the initial rise of the {sup 14}C-bomb pulse that is known to have occurred in surface ocean waters during 1958 {+-} 1 y in the northeast Pacific. The close temporal correspondence of the red abalone samplemore » series to regional {Delta}{sup 14}C records demonstrated the utility of the technique for validating age-at-length relationships for the red abalone. The findings provided support for a mean VBGF derived age of 32 y (range 30 to 33 y) for the specimen; however, the analysis of {sup 14}C data indicated that the specimen could be older.« less

Combined dendrochronological and radiocarbon dating of six Russian icons from the 15th-17th centuries

NASA Astrophysics Data System (ADS)

Dolgikh, A. V.; Matskovsky, V. V.; Voronin, K. V.; Solomina, O. N.

2017-06-01

The results of dendrochronological and radiocarbon dating by means of accelerator mass spectrometry (AMS) of six medieval icons, originating from northern European Russia and painted on wooden panels made from Scots pine, dated to the 15th to 17th centuries are presented. The panels of each icon were studied using dendrochronology. Five to six AMS dates were obtained for four icons. Although five icons were dendro-dated successfully, one failed to be reliably cross-dated with the existing master tree-ring chronologies and it was dated by radiocarbon wiggle-matching. Dendrochronological dating and wiggle-matching of radiocarbon dates allowed us to determine the narrow chronological intervals of icon creation.

Predicted net efflux of radiocarbon from the ocean and increase in atmospheric radiocarbon content

NASA Astrophysics Data System (ADS)

Caldeira, Ken; Rau, Greg H.; Duffy, Philip B.

Prior to changes introduced by man, production of radiocarbon (14C) in the stratosphere nearly balanced the flux of 14C from the atmosphere to the ocean and land biosphere, which in turn nearly balanced radioactive decay in these 14C reservoirs. This balance has been altered by land-use changes, fossil-fuel burning, and atmospheric nuclear detonations. Here, we use a model of the global carbon cycle to quantify these radiocarbon fluxes and make predictions about their magnitude in the future. Atmospheric nuclear detonations increased atmospheric 14C content by about 80% by the mid-1960's. Since that time, the 14C content of the atmosphere has been diminishing as this bomb radiocarbon has been entering the oceans and terrestrial biosphere. However, we predict that atmospheric 14C content will reach a minimum and start to increase within the next few years if fossil-fuel burning continues according to a “business-as-usual” scenario, even though fossil fuels are devoid of 14C. This will happen because fossil-fuel carbon diminishes the net flux of 14C from the atmosphere to the oceans and land biosphere, forcing 14C to accumulate in the atmosphere. Furthermore, the net flux of both bomb and natural 14C into the ocean are predicted to continue to slow and then, in the middle of the next century, to reverse, so that there will be a net flux of 14C from the ocean to the atmosphere. The predicted reversal of net 14C fluxes into the ocean is a further example of human impacts on the global carbon cycle.

Simulation of bombe radiocarbon transient in the Mediterranean Sea using a high-resolution regional model.

NASA Astrophysics Data System (ADS)

Ayache, Mohamed; Dutay, Jean-claude; Mouchet, Anne; Tisnérat-Laborde, Nadine; Houma-Bachari, Fouzia; Louanchi, Ferial; jean-baptiste, Philippe

2016-04-01

The radiocarbon isotope of carbon "14C", which a half-life of 5730 years, is continually formed naturally in the atmosphere by the neutron bombardment of 14N atoms. However, in the 1950s and early1960s, the atmospheric testing of thermonuclear weapons added a large amount of 14C into the atmosphere. The gradual infusion and spread of this "bomb" 14C through the oceans has provided a unique opportunity to gain insight into the specific rates characterizing the carbon cycle and ocean ventilations on such timescales. This numerical study provides, for the first time in the Mediterranean Sea, a simulation of the anthropogenic 14C invasion covers a 70-years period spanning the entire 14C generated by the bomb test, by using a high resolution regional model NEMO-MED12 (1/12° of horizontal resolution). This distribution and evolution of Δ14C of model is compared with recent high resolution 14C measurements obtained from surface water corals (Tisnérat-Laborde et al, 2013). In addition to providing constraints on the air-sea transfer of 14C, our work provides information on the thermohaline circulation and the ventilation of the deep waters to constrain the degree to which the NEMO-MED12 can reproduce correctly the main hydrographic features of the Mediterranean Sea circulation and its variations estimated from corals 14C time series measurements. This study is part of the work carried out to assess the robustness of the NEMO-MED12 model, which will be used to study the evolution of the climate and its effect on the biogeochemical cycles in the Mediterranean Sea, and to improve our ability to predict the future evolution of the Mediterranean Sea under the increasing anthropogenic pressure.

Using Inclination and Declination Data from South African Lake Sediment Records to Evaluate Radiocarbon-based Chronologies of the Past Millennium

NASA Astrophysics Data System (ADS)

Haberzettl, T.; Wündsch, M.; Kasper, T.; Meadows, M. E.; Stoner, J. S.; Su, Y.; Mäusbacher, R.

2016-12-01

Paleomagnetic data obtained from sedimentary archives are extremely scarce in South Africa. Attempts to extract such data from marine sediment cores on the South African shelf failed. This was very likely due to the high carbonate content in these sediments resulting in very low NRMs and hence a bad preservation of the directional data. Although NRMs are still very low it was possible to extract directional data from lacustrine sediments of coastal lakes on the Western Cape. Unfortunately, the radiocarbon-based chronologies for the sediments from these systems suffer from variable reservoir effects over time. In order to assess the quality of the established age-depth relations we compared inclination and declination data covering the past millennium from the two neighbouring lakes Eilandvlei and Swartvlei (Garden Route National Park, Wilderness Coastal Section) to predictions of the gufm1 magnetic field model derived from historical records (Jackson et al., 2000), the CALS3k.4 model (Korte and Constable, 2011) as well as archaeomagnetic data from the Limpopo region (Neukirch et al., 2012; Tarduno et al., 2015). Despite the large distance between the compared records (up to 1500 km) a very good agreement of the Eilandvlei data with the compared data was observed, which confirms the radiocarbon-based chronology from this site. However, a distinct underestimation of the reservoir effect at Swartvlei revealed by the paleomagnetic data lead to a re-evaluation of the chronology resulting in a temporal coverage of this record of only 400 years. Data from Eilandvlei show that inclination values vary around the ones expected, based on a geocentric axial dipole model (GAD) for the site latitude for the time interval 1000-400 cal BP. A distinct shift to steeper inclinations can be observed thereafter. This might reflect that the impact of the South Atlantic Anomaly at this location became more pronounced after 400 cal BP. Reference: Jackson, A. et al. 2000. Philosophical

Radiocarbon dating, chronologic framework, and changes in accumulation rates of holocene estuarine sediments from Chesapeake Bay

USGS Publications Warehouse

Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.

2002-01-01

Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

Ramped PyrOx 14C With a Twist: Improving Radiocarbon Chronologies on Highly Detrital Marginal Antarctic Sediments

NASA Astrophysics Data System (ADS)

Subt, C.; Yoon, H.; Yoo, K. C.; Lee, J. I.; Domack, E. W.; Rosenheim, B. E.

2016-02-01

Highly detrital sediments can be difficult to date when the detritus includes material similar to that from which dates are sought. For radiocarbon dating, samples with a high degree of pre-aged detrital carbon contamination necessitate measurement of a very small portion of the sample to remove that contamination from the targeted component, even when using advanced techniques such as Ramped PyrOx (RP) 14C dating. Here we present three case studies of alternative RP approaches, producing accurate and precise chronologies for highly detrital sediments near the Larsen C ice shelf, near the Drygalski Ice Tongue in Ross Sea, and in Lapeyrère Bay, Anvers Island. For sediments where the proportion of organic carbon that was modern at the time of deposition is too small for a traditional AMS analysis after RP treatment, we have developed an innovative multiple RP analyses approach to minimize the cost in precision from using smaller temperature intervals, while maximizing the benefit in accuracy. Resulting sub ice-shelf chronologies show vastly improved dates down-core, significantly younger than the equivalent 14C chronology from the bulk acid insoluble organic (AIO) carbon with increasing ages down-core. By comparison, bulk AIO 14C dates in the study areas are not only older, but are subject to age reversals and nearly constant ages that make sedimentation rates impossible to resolve. Using our new approaches, we can reduce pre-aged carbon contamination in Lapeyrère Bay, and date sediments within layers of siliceous mud and ooze in the Ross Sea, and near the Larsen C ice shelf. Improved accuracy for 14C dates of highly detrital sediments can sometimes require the incorporation of a larger blank correction to account for multiple analyses, decreasing the precision. Application of this method refines ages of hard-to-date sediments, removing limits on what to include in a regional approach to chronicle ice shelf collapse.

Quantity of dates trumps quality of dates for dense Bayesian radiocarbon sediment chronologies - Gas ion source 14C dating instructed by simultaneous Bayesian accumulation rate modeling

NASA Astrophysics Data System (ADS)

Rosenheim, B. E.; Firesinger, D.; Roberts, M. L.; Burton, J. R.; Khan, N.; Moyer, R. P.

2016-12-01

Radiocarbon (14C) sediment core chronologies benefit from a high density of dates, even when precision of individual dates is sacrificed. This is demonstrated by a combined approach of rapid 14C analysis of CO2 gas generated from carbonates and organic material coupled with Bayesian statistical modeling. Analysis of 14C is facilitated by the gas ion source on the Continuous Flow Accelerator Mass Spectrometry (CFAMS) system at the Woods Hole Oceanographic Institution's National Ocean Sciences Accelerator Mass Spectrometry facility. This instrument is capable of producing a 14C determination of +/- 100 14C y precision every 4-5 minutes, with limited sample handling (dissolution of carbonates and/or combustion of organic carbon in evacuated containers). Rapid analysis allows over-preparation of samples to include replicates at each depth and/or comparison of different sample types at particular depths in a sediment or peat core. Analysis priority is given to depths that have the least chronologic precision as determined by Bayesian modeling of the chronology of calibrated ages. Use of such a statistical approach to determine the order in which samples are run ensures that the chronology constantly improves so long as material is available for the analysis of chronologic weak points. Ultimately, accuracy of the chronology is determined by the material that is actually being dated, and our combined approach allows testing of different constituents of the organic carbon pool and the carbonate minerals within a core. We will present preliminary results from a deep-sea sediment core abundant in deep-sea foraminifera as well as coastal wetland peat cores to demonstrate statistical improvements in sediment- and peat-core chronologies obtained by increasing the quantity and decreasing the quality of individual dates.

Study of a metallurgical site in Tuscany (Italy) by radiocarbon dating

NASA Astrophysics Data System (ADS)

Cartocci, A.; Fedi, M. E.; Taccetti, F.; Benvenuti, M.; Chiarantini, L.; Guideri, S.

2007-06-01

Tuscany represents one of the most important ancient mining districts of Italy. Metalworking activities have been present in the area since ancient times and several mining centres have been active in the region since the Etruscan period. Two of the more notable mining locations are the island of Elba and the towns of Populonia and Massa Marittima. In order to reconstruct the development of metallurgical techniques in the past, a multi-disciplinary approach is required, involving both archaeological study and archaeometric analysis of the sites of interest. One of the most complex problems is establishing the chronological history of metallurgical exploitation in ancient sites: archaeological remains are sometimes incomplete and the stratigraphy of archaeological horizons might have been deeply altered. Thus, direct dating of metallurgical slags and other remains of mining and metalworking activities using radiocarbon measurements is particularly useful for developing site chronologies. Charcoal samples from a recent excavation in Populonia were dated by AMS radiocarbon in order to reconstruct the chronological evolution of ancient metallurgical production; results reported here are consistent with archaeological observations.

14C dates from Tel Rehov: Iron-Age chronology, pharaohs, and Hebrew kings.

PubMed

Bruins, Hendrik J; van der Plicht, Johannes; Mazar, Amihai

2003-04-11

Stratified radiocarbon dates provide an independent chronological link between archaeological layers and historical data. The invasion by Pharaoh Shoshenq I (Shishak) is a key historical synchronism, approximately 925 B.C.E., mentioned in both Egyptian inscriptions and the Hebrew Bible. The list of places raided by Shoshenq, mentioned at Karnak (Egypt), includes Rehov (Israel). The site yielded a consistent series of radiocarbon dates from the 12th to 9th century B.C.E. Our results (i) suggest a revised Iron-Age chronology; (ii) date an archaeological stratum to Shoshenq's campaign; (iii) indicate the similarity of "Solomonic" and "Omride" pottery; and (iv) provide correlation with Greece and Cyprus.

The transfer of bomb radiocarbon and anthropogenic lead to the deep North Atlantic Ocean observed from a deep sea coral

NASA Astrophysics Data System (ADS)

Lee, Jong-Mi; Eltgroth, Selene F.; Boyle, Edward A.; Adkins, Jess F.

2017-01-01

Deep-ocean, Δ14C, Pb concentrations, and Pb isotopes were reconstructed from a deep-sea coral Enallopsammia rostrata from 1410 m depth off of Bermuda. Our high-resolution time series is created from closely spaced radial cross sections, with samples taken from the center of concentric coral growth bands that we show to be the oldest portion of the section. Prebomb radiocarbon ages from the coral demonstrate that the vertical growth rate of the coral is linear, and the age of the coral is estimated to be 560-630 yr old based on the growth rate. Using this age model to reconstruct Δ14C in deep seawater, we first detect bomb radiocarbon at the coral growth site around 1980, and show that Δ14C increased from - 80 ± 1 ‰ (average 1930-1979) to a plateau at - 39 ± 3 ‰ (1999-2001). Pb/Ca of the coral ranges between 1.1-4.5 nmol/mol during the 16th and 17th centuries, and Pb isotope ratios (206Pb/207Pb = 1.21, 208Pb/207Pb = 2.495) in this period agree with pre-anthropogenic values found in the pelagic sediments of the North Atlantic Ocean basin. Coral Pb/Ca is slightly elevated to 6.2 ± 0.9 nmol /mol between the 1740s and the 1850s and then increases to 25.1 ± 0.2 nmol /mol in the 1990s. The increase in coral Pb/Ca is accompanied by a decrease in coral 206Pb/207Pb and 208Pb/207Pb, indicating that the increase was caused by the infiltration of anthropogenic Pb to the coral growth site. Comparing our data to the surface coral Δ14C and Pb records from Bermuda reveals a time scale of tracer transport from the surface ocean to the coral growth site. Some characteristic features, e.g., the bomb-derived Δ14C increase, appear in the deep ocean approximately 25 yr later than the surface, but the overall increase of Δ14C and Pb in the deep ocean is smaller and slower than the surface, showing the importance of mixing during the transport of these tracers.

Radiocarbon dating with annual-resolution of subfossil trees from the Younger Dryas event in the southern French Alps

NASA Astrophysics Data System (ADS)

Capano, Manuela; Miramont, Cécile; Guibal, Frédéric; Kromer, Bernd; Tuna, Thibaut; Fagault, Yoann; Bard, Edouard

2017-04-01

Tree rings are an important archive for the calibration of radiocarbon data. The younger part of the IntCal curve is based essentially on tree-ring chronologies, absolutely dated by dendrochronological analysis. For the Northern Hemisphere (NH), a gap still exists between the absolutely dated sequences and a floating chronology. Based on the Southern Hemisphere (SH) tree-ring chronologies a link has been previously proposed (Reimer et al. 2013, Radiocarbon; see also update in Hogg et al. 2016, Radiocarbon). By measuring radiocarbon at annual resolution in French subfossil pines (Pinus sylvestris L.) we propose to improve the connection between the absolute chronology and the floating chronology. Several subfossil pines have been found in the Southern French Alps; they were buried by flood deposits, allowing their preservation. Some trees discovered in the Barbier riverbed were dated to the Younger Dryas periods by previous decadal radiocarbon measurements, performed in Heidelberg and Mannheim. The trees selected for our new study are Barb12 and Barb17 (analyzed sequences of 163 and 152 rings, respectively). These sequences were sampled at annual resolution when permitted by the ring width. As a first step, every third ring was pretreated for radiocarbon analysis. These samples were sliced in small pieces and pretreated by using the ABA-B method before being combusted, graphitized with the AGE system and measured with AixMICADAS (Bard et al. 2015, Nucl. Instr. Meth. B). From the comparison with the kauri sequence, the Barb12-17 sequence can be dated from about 12835 to 12606 cal. BP. It can also be used to calculate the interhemispheric gradient (IHG) over the overlapping period. In order to reduce the inter-annual variability, the Barb12-17 record was smoothed, grouped and averaged over the same decades as in the Kauri record. On the basis of twenty values, a mean IHG value of ca. 60 years was calculated. Quantification of the IHG around 50 yr is particularly

Comparing records with related chronologies

NASA Astrophysics Data System (ADS)

Bronk Ramsey, Christopher; Albert, Paul; Kearney, Rebecca; Staff, Richard A.

2016-04-01

In order to integrate ice, terrestrial and marine records, it is necessary to deal with records on different timescales. These timescales can be grouped into those that use a common fundamental chronometer (such as Uranium-Thorium dating or Radiocarbon) and can also be related to one another where we have chronological tie points such as tephra horizons. More generally we can, through a number of different methodologies, derive relationships between different timescales. A good example of this is the use of cosmogenic isotope production, specifically 10Be and 14C to relate the calibrated radiocarbon timescale to that of the Greenland ice cores. The relationships between different timescales can be mathematically expressed in terms of time-transfer functions. This formalism allows any related record to be considered against any linked timescale with an appropriate associated uncertainty. The prototype INTIMATE chronological database allows records to be viewed and compared in this way and this is now being further developed, both to include a wider range of records and also to provide better connectivity to other databases and chronological tools. These developments will also include new ways to use tephra tie-points to constrain the relationship between timescales directly, without needing to remodel each associated timescale. The database as it stands allows data for particular timeframes to be recalled and plotted against any timescale, or exported in spreadsheet format. New functionality will be added to allow users to work with their own data in a private space and then to publish it when it has been through the peer-review publication process. In order to make the data easier to use for other further analysis and plotting, and with data from other sources, the database will also act as a server to deliver data in a JSON format. The aim of this work is to make the comparison of integrated data much easier for researchers and to ensure that good practice in

A Selective Chronology of Terrorist and Counter-Terrorist Incidents.

ERIC Educational Resources Information Center

Totten, Sam

1986-01-01

Beginning with the July 22, 1966, Palestinian hijacking of an El Al airliner and ending with the April 5, 1986, bombing raid on Libya by the United States, this chronology details 56 terrorist events which were covered in the world press. (JDH)

Constraining global air-sea gas exchange for CO2 with recent bomb 14C measurements

NASA Astrophysics Data System (ADS)

Sweeney, Colm; Gloor, Emanuel; Jacobson, Andrew R.; Key, Robert M.; McKinley, Galen; Sarmiento, Jorge L.; Wanninkhof, Rik

2007-06-01

The 14CO2 released into the stratosphere during bomb testing in the early 1960s provides a global constraint on air-sea gas exchange of soluble atmospheric gases like CO2. Using the most complete database of dissolved inorganic radiocarbon, DI14C, available to date and a suite of ocean general circulation models in an inverse mode we recalculate the ocean inventory of bomb-produced DI14C in the global ocean and confirm that there is a 25% decrease from previous estimates using older DI14C data sets. Additionally, we find a 33% lower globally averaged gas transfer velocity for CO2 compared to previous estimates (Wanninkhof, 1992) using the NCEP/NCAR Reanalysis 1 1954-2000 where the global mean winds are 6.9 m s-1. Unlike some earlier ocean radiocarbon studies, the implied gas transfer velocity finally closes the gap between small-scale deliberate tracer studies and global-scale estimates. Additionally, the total inventory of bomb-produced radiocarbon in the ocean is now in agreement with global budgets based on radiocarbon measurements made in the stratosphere and troposphere. Using the implied relationship between wind speed and gas transfer velocity ks = 0.27(Sc/660)-0.5 and standard partial pressure difference climatology of CO2 we obtain an net air-sea flux estimate of 1.3 ± 0.5 PgCyr-1 for 1995. After accounting for the carbon transferred from rivers to the deep ocean, our estimate of oceanic uptake (1.8 ± 0.5 PgCyr-1) compares well with estimates based on ocean inventories, ocean transport inversions using ocean concentration data, and model simulations.

Forensic applications of 14C bomb-pulse dating

NASA Astrophysics Data System (ADS)

Zoppi, U.; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A.

2004-08-01

After a brief review of the basics of 14C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the 14C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of 14C concentrations in milligram samples taken from seized drugs are presented. 14C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

Decadally resolved Lateglacial radiocarbon evidence from New Zealand kauri

NASA Astrophysics Data System (ADS)

Hogg, Alan; Southon, John; Turney, Chris; Palmer, Jonathan; Bronk Ramsey, Christopher; Fenwick, Pavla; Boswijk, Gretel; Büntgen, Ulf; Friedrich, Michael; Helle, Gerhard; Hughen, Konrad; Jones, Richard; Kromer, Bernd; Noronha, Alexandra; Reinig, Frederick; Reynard, Linda; Staff, Richard; Wacker, Lukas

2017-04-01

The Last Glacial-Interglacial Transition (LGIT; 15,000 - 11,000 cal BP) was characterised by complex spatiotemporal patterns of climate change, with numerous studies requiring accurate chronological control to decipher leads from lags in global palaeoclimatic, -environmental and archaeological records. However, close scrutiny of the few available tree-ring chronologies and radiocarbon-dated sequences composing the IntCal13 radiocarbon (14C) calibration curve, indicates significant weakness in 14C calibration across key periods of the LGIT. Here, we present a decadally-resolved atmospheric 14C record derived from New Zealand kauri spanning Greenland Stadial 1 (GS-1; 12,900 - 11,650 cal BP). Two floating kauri 14C time series, curve-matched to IntCal13, serve as a radiocarbon backbone through GS-1. Floating Northern Hemisphere (NH) 14C datasets are matched against the new kauri data, forming a robust NH 14C time series to 14,200 cal BP. Our results show that IntCal13 is questionable from 12,200 - 11,900 cal BP and the 10,400 BP 14C plateau is approximately five decades too short. By precisely aligning Southern and Northern Hemisphere tree-ring 14C records with marine 14C sequences, we document two relatively short periods of North Atlantic Meridional Overturning Circulation (AMOC) collapse during GS-1. Hence, sustained North Atlantic cooling across GS-1 was not driven by a prolonged AMOC reduction but was probably due to an equatorward migration of the Polar Front.

Bomb-produced radiocarbon in the western tropical Pacific Ocean: Guam coral reveals operation-specific signals from the Pacific Proving Grounds

NASA Astrophysics Data System (ADS)

Andrews, Allen H.; Asami, Ryuji; Iryu, Yasufumi; Kobayashi, Donald R.; Camacho, Frank

2016-08-01

High-resolution radiocarbon (14C) analyses on a coral core extracted from Guam, a western tropical Pacific island, revealed a series of early bomb-produced 14C spikes. The typical marine bomb 14C signal—phase lagged and attenuated relative to atmospheric records—is present in the coral and is consistent with other regional coral records. However, 14C levels well above what can be attributed to air-sea diffusion alone punctuate this pattern. This anomaly was observed in other Indo-Pacific coral records, but the Guam record is unmatched in magnitude and temporal resolution. The Guam coral Δ14C record provided three spikes in 1954-1955, 1956-1957, and 1958-1959 that are superimposed on a normal 14C record. Relative to mean prebomb levels, the first peak rises an incredible ˜700‰ and remained elevated for ˜1.2 years. A follow up assay with finer resolution increased the peak by ˜300‰. Subsequent spikes were less intense with a rise of ˜35 and ˜70‰. Each can be linked to thermonuclear testing in the Pacific Proving Grounds at Bikini and Enewetak atolls in Operations Castle (1954), Redwing (1956), and Hardtack I (1958). These 14C signals can be explained by vaporization of coral reef material in the nuclear fireball, coupled with neutron activation of atmospheric nitrogen (14C production), and subsequent absorption of 14CO2 to form particulate carbonates of close-in fallout. The lag time in reaching Guam and other coral records abroad was tied to ocean surface currents and modeling provided validation of 14C arrival observations.

Radiocarbon ages on late pleistocene loess stratigraphy of Nebraska and Kansas, Central Great Plains, U.S.A.

NASA Astrophysics Data System (ADS)

Martin, Charles W.

In the central Great Plains of the United States, radiocarbon dating of loess and buried soils is clarifying the late Quaternary loess chronology for the period 25,000 to 10,000 BP. Along Harland Lake, Nebraska, a soil developed in the Gilman Canyon Formation and overlain by Peoria Loess has radiocarbon ages on soil humates of 30,700 to 21,500 BP. At one site, two Picea charcoal bands in the lower meter of Peoria Loess have radiocarbon ages of 21,250 and 19,730 BP. Therefore, in the vicinity of Harlan Lake, deposition of Peoria Loess apparently began around 21,000 BP. Peoria Loess deposition appears to have been interrupted by an episode of river entrenchment prior to 12,600 BP. Spring activity shortly thereafter suggests that incision was coeval to an increase in effective moisture. The termination of Peoria Loess deposition is marked by the Brady Soil, which in the Harlan Lake area has radiocarbon ages on soil humates of 11,800 to 10,200 BP. Comparison of the Harlan Lake chronology with chronologies completed elsewhere in the central Great Plains reveals general synchrony among periods of pedogenesis and Peoria Loess deposition. Little is known, however, about vegetation conditions in the region when loess was accumulating. Charcoal has been noted chiefly in the basal Peoria Loess, suggesting that some trees were present during initial Peoria Loess deposition. The extent of this tree cover is unknown, however. Charcoal is rare in the middle and upper Peoria Loess.

Radiocarbon dating late Quaternary loess deposits using small terrestrial gastropod shells

USGS Publications Warehouse

Pigati, Jeff S.; McGeehin, John P.; Muhs, Daniel R.; Bettis, E. Arthur

2013-01-01

Constraining the ages and mass accumulation rates of late Quaternary loess deposits is often difficult because of the paucity of organic material typically available for 14C dating and the inherent limitations of luminescence techniques. Radiocarbon dating of small terrestrial gastropod shells may provide an alternative to these methods as fossil shells are common in loess and contain ∼12% carbon by weight. Terrestrial gastropod assemblages in loess have been used extensively to reconstruct past environmental conditions but have been largely ignored for dating purposes. Here, we present the results of a multi-faceted approach to understanding the potential for using small terrestrial gastropod shells to date loess deposits in North America. First, we compare highly resolved 14C ages of well-preserved wood and gastropod shells (Succineidae) recovered from a Holocene loess section in Alaska. Radiocarbon ages derived from the shells are nearly identical to wood and plant macrofossil ages throughout the section, which suggests that the shells behaved as closed systems with respect to carbon for at least the last 10 ka (thousands of calibrated 14C years before present). Second, we apply 14C dating of gastropod shells to late Pleistocene loess deposits in the Great Plains using stratigraphy and independent chronologies for comparison. The new shell ages require less interpretation than humic acid radiocarbon ages that are commonly used in loess studies, provide additional stratigraphic coverage to previous dating efforts, and are in correct stratigraphic order more often than their luminescence counterparts. Third, we show that Succineidae shells recovered from historic loess in the Matanuska River Valley, Alaska captured the 20th century 14C bomb spike, which suggests that the shells can be used to date late Holocene and historic-aged loess. Finally, results from Nebraska and western Iowa suggest that, similar to other materials, shell ages approaching ∼40 ka should

Radiocarbon and stable isotope investigations at the Central Rhineland sites of Gönnersdorf and Andernach-Martinsberg, Germany.

PubMed

Stevens, Rhiannon E; O'Connell, Tamsin C; Hedges, Robert E M; Street, Martin

2009-08-01

The late glacial open-air sites of Gönnersdorf and Andernach-Martinsberg in the German Central Rhineland are well known for their Magdalenian occupation and activities. The latter site also produced evidence for a younger, Final Palaeolithic occupation of the locality by people of the Federmessergruppen. Both sites are particularly well preserved, largely due to their burial beneath volcanic deposits of the late glacial Laacher See eruption. We conducted a program of AMS radiocarbon dating and stable isotope analyses with the aim of improving understanding of the chronological history and ecological setting of the two sites. Previously published radiocarbon dates appeared to indicate that the earliest Magdalenian occupation at Gönnersdorf fell around 12,900 uncalibrated (14)C yr BP, while the earliest occupation at Andernach may have been more than 500 radiocarbon years earlier. The AMS determinations presented here revise this impression and suggest that the onset of occupation at the two sites was in fact simultaneous and prior to the warming of Greenland Interstadial GI 1e. At Gönnersdorf, a chronological hiatus exists between the main Magdalenian faunal assemblage and mega-faunal remains interpreted as collected sub-fossil material. At Andernach-Martinsberg, there is a clear chronological hiatus between the Magdalenian occupation and subsequent Federmessergruppen activities at the site. However, an intermediate radiocarbon date on an atypically preserved horse bone is suggestive of ephemeral human visits to the site between these well demonstrated phases. A date of similar age on an elk bone from Gönnersdorf may indicate broadly contemporaneous human presence at Gönnersdorf too. Stable isotope analysis of faunal remains from Gönnersdorf and Andernach-Martinsberg was conducted with the aim of both reconstructing and comparing local environmental conditions at the two sites, and also potentially identifying subtle variations in the chronological development

The impact of Last Glacial climate variability in west-European loess revealed by radiocarbon dating of fossil earthworm granules.

PubMed

Moine, Olivier; Antoine, Pierre; Hatté, Christine; Landais, Amaëlle; Mathieu, Jérôme; Prud'homme, Charlotte; Rousseau, Denis-Didier

2017-06-13

The characterization of Last Glacial millennial-timescale warming phases, known as interstadials or Dansgaard-Oeschger events, requires precise chronologies for the study of paleoclimate records. On the European continent, such chronologies are only available for several Last Glacial pollen and rare speleothem archives principally located in the Mediterranean domain. Farther north, in continental lowlands, numerous high-resolution records of loess and paleosols sequences show a consistent environmental response to stadial-interstadial cycles. However, the limited precision and accuracy of luminescence dating methods commonly used in loess deposits preclude exact correlations of paleosol horizons with Greenland interstadials. To overcome this problem, a radiocarbon dating protocol has been developed to date earthworm calcite granules from the reference loess sequence of Nussloch (Germany). Its application yields a consistent radiocarbon chronology of all soil horizons formed between 47 and 20 ka and unambiguously shows the correlation of every Greenland interstadial identified in isotope records with specific soil horizons. Furthermore, eight additional minor soil horizons dated between 27.5 and 21 ka only correlate with minor decreases in Greenland dust records. This dating strategy reveals the high sensitivity of loess paleoenvironments to Northern Hemisphere climate changes. A connection between loess sedimentation rate, Fennoscandian ice sheet dynamics, and sea level changes is proposed. The chronological improvements enabled by the radiocarbon "earthworm clock" thus strongly enhance our understanding of loess records to a better perception of the impact of Last Glacial climate changes on European paleoenvironments.

The impact of Last Glacial climate variability in west-European loess revealed by radiocarbon dating of fossil earthworm granules

PubMed Central

Moine, Olivier; Antoine, Pierre; Hatté, Christine; Landais, Amaëlle; Mathieu, Jérôme; Prud’homme, Charlotte

2017-01-01

The characterization of Last Glacial millennial-timescale warming phases, known as interstadials or Dansgaard–Oeschger events, requires precise chronologies for the study of paleoclimate records. On the European continent, such chronologies are only available for several Last Glacial pollen and rare speleothem archives principally located in the Mediterranean domain. Farther north, in continental lowlands, numerous high-resolution records of loess and paleosols sequences show a consistent environmental response to stadial–interstadial cycles. However, the limited precision and accuracy of luminescence dating methods commonly used in loess deposits preclude exact correlations of paleosol horizons with Greenland interstadials. To overcome this problem, a radiocarbon dating protocol has been developed to date earthworm calcite granules from the reference loess sequence of Nussloch (Germany). Its application yields a consistent radiocarbon chronology of all soil horizons formed between 47 and 20 ka and unambiguously shows the correlation of every Greenland interstadial identified in isotope records with specific soil horizons. Furthermore, eight additional minor soil horizons dated between 27.5 and 21 ka only correlate with minor decreases in Greenland dust records. This dating strategy reveals the high sensitivity of loess paleoenvironments to Northern Hemisphere climate changes. A connection between loess sedimentation rate, Fennoscandian ice sheet dynamics, and sea level changes is proposed. The chronological improvements enabled by the radiocarbon “earthworm clock” thus strongly enhance our understanding of loess records to a better perception of the impact of Last Glacial climate changes on European paleoenvironments. PMID:28559353

High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia.

PubMed

Wilmshurst, Janet M; Hunt, Terry L; Lipo, Carl P; Anderson, Atholl J

2011-02-01

The 15 archipelagos of East Polynesia, including New Zealand, Hawaii, and Rapa Nui, were the last habitable places on earth colonized by prehistoric humans. The timing and pattern of this colonization event has been poorly resolved, with chronologies varying by >1000 y, precluding understanding of cultural change and ecological impacts on these pristine ecosystems. In a meta-analysis of 1,434 radiocarbon dates from the region, reliable short-lived samples reveal that the colonization of East Polynesia occurred in two distinct phases: earliest in the Society Islands A.D. ∼1025-1120, four centuries later than previously assumed; then after 70-265 y, dispersal continued in one major pulse to all remaining islands A.D. ∼1190-1290. We show that previously supported longer chronologies have relied upon radiocarbon-dated materials with large sources of error, making them unsuitable for precise dating of recent events. Our empirically based and dramatically shortened chronology for the colonization of East Polynesia resolves longstanding paradoxes and offers a robust explanation for the remarkable uniformity of East Polynesian culture, human biology, and language. Models of human colonization, ecological change and historical linguistics for the region now require substantial revision.

High-precision radiocarbon dating shows recent and rapid initial human colonization of East Polynesia

PubMed Central

Wilmshurst, Janet M.; Hunt, Terry L.; Lipo, Carl P.; Anderson, Atholl J.

2011-01-01

The 15 archipelagos of East Polynesia, including New Zealand, Hawaii, and Rapa Nui, were the last habitable places on earth colonized by prehistoric humans. The timing and pattern of this colonization event has been poorly resolved, with chronologies varying by >1000 y, precluding understanding of cultural change and ecological impacts on these pristine ecosystems. In a meta-analysis of 1,434 radiocarbon dates from the region, reliable short-lived samples reveal that the colonization of East Polynesia occurred in two distinct phases: earliest in the Society Islands A.D. ∼1025–1120, four centuries later than previously assumed; then after 70–265 y, dispersal continued in one major pulse to all remaining islands A.D. ∼1190–1290. We show that previously supported longer chronologies have relied upon radiocarbon-dated materials with large sources of error, making them unsuitable for precise dating of recent events. Our empirically based and dramatically shortened chronology for the colonization of East Polynesia resolves longstanding paradoxes and offers a robust explanation for the remarkable uniformity of East Polynesian culture, human biology, and language. Models of human colonization, ecological change and historical linguistics for the region now require substantial revision. PMID:21187404

New radiocarbon dates for terminal Pleistocene and early Holocene settlements in West Turkana, northern Kenya

NASA Astrophysics Data System (ADS)

Beyin, Amanuel; Prendergast, Mary E.; Grillo, Katherine M.; Wang, Hong

2017-07-01

The Turkana Basin in northern Kenya is located in an environmentally sensitive region along the eastern African Rift system. Lake Turkana's sensitivity to fluctuations in precipitation makes this an ideal place to study prehistoric human adaptations during key climatic transitions. Here we present eleven radiocarbon dates from two recently excavated sites in West Turkana, Kokito 01 and Kokito 02. The sites span the Pleistocene-Holocene transition, a time of fluctuating lake levels and novel cultural responses within the region. Several scenarios are laid out for the interpretation of site chronologies, and these are discussed with reference to the terminal Pleistocene and early Holocene chronological record for the region. Given the paucity of well-dated sites from this timespan in the Turkana Basin, the new radiocarbon dates are an important step toward establishing human settlement history and associated cultural developments in the region.

The radiocarbon budget for Mono Lake: an unsolved mystery

USGS Publications Warehouse

Broecker, W.S.; Wanninkhof, R.; Mathieu, G.; Peng, T.-H.; Stine, S.; Robinson, S.; Herczeg, A.; Stuiver, M.

1988-01-01

Since 1957 the 14C C ratio of the dissolved inorganic carbon in Mono Lake has risen by about 60???. The magnitude of this increase is about four times larger than that expected from the invasion of bomb-produced 14C from the atmosphere. We have eliminated the following explanations: (1) measurement error, (2) an unusually high physical exchange rate for non-reactive gases, (3) inorganic enhancement of the CO2 exchange rate, and (4) biological enhancement of the CO2 exchange rate. Clandestine disposal of waste radiocarbon remains a dark-horse explanation. In the course of our investigations we have uncovered evidence for at least one episodic input of radiocarbon-free carbon to the lake over the last 1000 years. We speculate that this injection was related to a hydrothermal event resulting from sublacustrine volcanic activity. ?? 1988.

Year of birth determination using radiocarbon dating of dental enamel

PubMed Central

Buchholz, B.A.; Spalding, K.L

2010-01-01

Radiocarbon dating is typically an archaeological tool rather than a forensic one. Recently however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite and carbon-14 (14C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, 14C levels in the enamel represent 14C levels in the atmosphere at the time of its formation. In this paper we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases police will try to match particulars of the unidentified individual (which is often only gender and/or an estimate of age), with particulars from missing persons lists. PMID:20976120

Year of birth determination using radiocarbon dating of dental enamel.

PubMed

Buchholz, B A; Spalding, K L

2010-05-01

Radiocarbon dating is typically an archaeological tool rather than a forensic one. Recently however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite and carbon-14 ((14)C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, (14)C levels in the enamel represent (14)C levels in the atmosphere at the time of its formation. In this paper we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases police will try to match particulars of the unidentified individual (which is often only gender and/or an estimate of age), with particulars from missing persons lists.

Concordance of Collagen-Based Radiocarbon and Aspartic-Acid Racemization Ages

PubMed Central

Bada, Jeffrey L.; Schroeder, Roy A.; Protsch, Reiner; Berger, Rainer

1974-01-01

By determining the extent of racemization of aspartic acid in a well-dated bone, it is possible to calculate the in situ first-order rate constant for the interconversion of the L and D enantiomers of aspartic acid. Collagen-based radiocarbon-dated bones are shown to be suitable samples for use in “calibrating” the racemization reaction. Once the aspartic-acid racemization reaction has been “calibrated” for a site, the reaction can be used to date other bones from the deposit. Ages deduced by this method are in good agreement with radiocarbon ages. These results provide evidence that the aspartic-acid racemization reaction is an important chronological tool for dating bones either too old or too small for radiocarbon dating. As an example of the potential application of the technique for dating fossil man, a piece of Rhodesian Man from Broken Hill, Zambia, was analyzed and tentatively assigned an age of about 110,000 years. PMID:4522802

On the radiocarbon record in banded corals: exchange parameters and net transport of /sup 14/CO/sub 2/ between atmosphere and surface ocean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Druffel, E.M.; Suess, H.E.

1983-02-20

We have made radiocarbon measurements of banded hermatypic corals from Florida, Belize, and the Galapagos Islands. Interpretation is presented here of these previously reported results. These measurements represent the /sup 14/C//sup 12/C ratios in dissolved inorganic carbon (DIOC) in the surface ocean waters of the Gulf Stream and the Peru Current at the time of coral ring formation. A depletion in radiocarbon concentration was observed incoral rings that grew from A.D. 1900--1952. It was caused by dilution of existing /sup 14/C levels with dead CO/sub 2/ from fossil fuel burning (the Suess effect, or S/sub e/). A similar trend wasmore » observed in the distribution of bomb-produced /sup 14/C in corals that had grown during the years following A.D. 1952. The concentration of bomb-produced radiocarbon was much higher in corals from temperate regions (Florida, Belize, Hawaiian Islands) than in corals from tropical regions (Galapagos Islands and Canton Island). The apparent radiocarbon ages of the surface waters in temperate and tropical oceans during the preanthropogenic period range from about 280 to 520 years B.P. (-40 to -69%). At all investigated locations, it is likely that waters at subsurface depths have the same apparent radiocarbon age of about 670 years B.P. From the change of oceanic ..delta../sup 14/C in the surface during post-bomb times, the approximate annual rate of net input of /sup 14/CO/sub 2/ to the ocean waters is calculated to be about 8% of the prevailing /sup 14/C difference between atmosphere and ocean. From this input and from preanthropogenic ..delta../sup 14/C values found at each location, it can be seen that vertical mixing of water in the Peru Current is about 3 times greater than that in the Gulf Stream.« less

Ancient Egyptian chronology and the astronomical orientation of pyramids.

PubMed

Spence, K

2000-11-16

The ancient Egyptian pyramids at Giza have never been accurately dated, although we know that they were built approximately around the middle of the third millennium BC. The chronologies of this period have been reconstructed from surviving lists of kings and the lengths of their reigns, but the lists are rare, seldom complete and contain known inconsistencies and errors. As a result, the existing chronologies for that period (the Old Kingdom) can be considered accurate only to about +/-100 years, a figure that radiocarbon dating cannot at present improve. Here I use trends in the orientation of Old Kingdom pyramids to demonstrate that the Egyptians aligned them to north by using the simultaneous transit of two circumpolar stars. Modelling the precession of these stars yields a date for the start of construction of the Great Pyramid that is accurate to +/-5 yr, thereby providing an anchor for the Old Kingdom chronologies.

Ancient Egyptian chronology and the astronomical orientation of pyramids

NASA Astrophysics Data System (ADS)

Spence, Kate

2000-11-01

The ancient Egyptian pyramids at Giza have never been accurately dated, although we know that they were built approximately around the middle of the third millennium BC. The chronologies of this period have been reconstructed from surviving lists of kings and the lengths of their reigns, but the lists are rare, seldom complete and contain known inconsistencies and errors. As a result, the existing chronologies for that period (the Old Kingdom) can be considered accurate only to about +/-100 years, a figure that radiocarbon dating cannot at present improve. Here I use trends in the orientation of Old Kingdom pyramids to demonstrate that the Egyptians aligned them to north by using the simultaneous transit of two circumpolar stars. Modelling the precession of these stars yields a date for the start of construction of the Great Pyramid that is accurate to +/-5 yr, thereby providing an anchor for the Old Kingdom chronologies.

Surface Ocean Radiocarbon Reservoir Ages From Land-Sea Tephra Correlation Constrains Deglacial Chronology and Ocean Circulation in the Southeast Bering Sea

NASA Astrophysics Data System (ADS)

Cook, M. S.; Miller, R.; White-Nockleby, C.; Chapman, A.; Mix, A. C.

2017-12-01

Radiocarbon estimates of the past ocean are valuable because unlike passive tracers, radiocarbon has the potential to trace both the distribution and rate of transport of water masses. Most studies using paired radiocarbon measurements on planktonic and benthic foraminifera assume that the surface reservoir age was constant at the preindustrial value, which if incorrect, can strongly bias radiocarbon reconstructions. The subarctic Pacific is ringed by volcanic arcs, and there is great potential to use tephrochronology as a stratigraphic tool in sediments from the last glacial and deglaciation, and assign calendar ages to the marine sediment without relying on calibrated planktonic radiocarbon ages. In this study, we use major and trace element analysis of volcanic glass to match tephras between radiocarbon-dated lake cores from Sanak Island in the eastern Aleutians to marine cores from Umnak Plateau in the southeast Bering Sea. There are numerous thin tephras preserved in laminated sediments from the Bolling-Allerod and early Holocene in marine cores from depths (1000-1500 m) within the modern oxygen minimum zone. We find that trace elements are crucial in distinguishing tephras from individual eruptions. Our preliminary radiocarbon measurements suggest that the benthic-atmosphere radiocarbon differences and marine surface reservoir ages in the Bolling-Allerod are similar to pre-industrial values, supporting previously published radiocarbon reconstructions from the region.

Year of Birth Determination Using Radiocarbon Dating of Dental Enamel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchholz, B A; Spalding, K L

2009-03-10

Radiocarbon dating is typically an archaeological tool rather than a forensic one. Recently however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite and carbon-14 ({sup 14}C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, {sup 14}C levels in the enamel represent {sup 14}C levels in the atmosphere at the time of its formation. Inmore » this paper we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases police will try to match particulars of the unidentified individual (which is often only gender and/or an estimate of age), with particulars from missing persons lists.« less

Radiocarbon chronology of the last deglaciation in the Baffin Bay reveals asynchronous melting of Arctic and Laurentide ice sheets

NASA Astrophysics Data System (ADS)

Jackson, Rebecca; Kucera, Michal; Vogt, Christoph; Wacker, Lukas

2016-04-01

The transition from the last ice age into the Holocene interglacial was characterised by rapid retreat of North American ice sheets, discharging large quantities of meltwater into the Labrador Sea. Whereas the meltwater chronology of the Laurentide Ice Sheet is well documented, the deglacial history of the American Arctic ice sheets (Inuit Ice sheet and northern Greenland Ice Sheet) draining into the Labrador Sea via the Baffin Bay is less well constrained. Here we present the first high-resolution radiocarbon-dated deglacial records from the Canadian and Greenland margins of the central Baffin Bay. Sedimentological and geochemical data confirm the presence during Termination I of two events of enhanced delivery of detrital carbonate (Baffin Bay Detrital Carbonate Events) dated to 14.2-13.7 ka BP and 12.7-11 ka BP. The events are synchronous across the Baffin Bay and their mineralogical signature indicates a common source of detrital carbonate from the Canadian Arctic, with a synchronous clastic source proximal to Greenland. The events postdate Heinrich layers and their onset is not linked to Greenland temperature change. This indicates that the deglaciation of American Arctic ice sheets and associated meltwater discharge were decoupled from the dominant North Atlantic climate mode.

High-resolution climate signals in the Bølling Allerød Interstadial (Greenland Interstadial 1) as reflected in European tree-ring chronologies compared to marine varves and ice-core records

NASA Astrophysics Data System (ADS)

Friedrich, Michael; Kromer, Bernd; Kaiser, Klaus F.; Spurk, Marco; Hughen, Konrad A.; Johnsen, Sigfus J.

2001-05-01

Lateglacial and Holocene tree-ring chronologies are unique archives, which provide various information on past environments on a true annual time scale. Changes in ring-width can be related to past climate anomalies and dendrodated wood provides an ideal source for radiocarbon calibration. We present a 1051 year tree-ring chronology from the Late Glacial, built from subfossil Scots pines (Pinus sylvestris) that grew in different regions of Central and Southern Europe. Through a series of high-precision radiocarbon measurements we obtained a floating radiocarbon chronology, which allowed accurate wiggle-matching to the INTCAL98 calibration curve. The trees show a coherent pattern in ring-width variations throughout Central Europe, and extending into the Mediterranean, which indicates a strong external climatic factor, most probably temperature during the growing season. We identified major growth events, which appear synchronous with events seen in isotopic and tracer signals in the Greenland ice cores and with changes in the strength of upwelling in the Cariaco Basin.

Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, A H; Kerr, L A; Cailliet, G M

2007-11-04

Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, themore » unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.« less

Investigating the Impact of Past and Future CO2 Emissions on the Distribution of Radiocarbon in the Ocean

NASA Astrophysics Data System (ADS)

Khatiwala, S.; Payne, S.; Graven, H. D.; Heimbach, P.

2015-12-01

The ocean is a significant sink for carbon dioxide from fossil fuel burning, absorbing roughly a third of human CO2 emitted over the industrial period. This has implications not only for climate but also for the chemical and isotopic composition of the ocean. Human activities have increased the ocean radiocarbon content through nuclear bomb tests in the 1950s-60s, which released a large amount of radiocarbon (14C) into the atmosphere, but fossil fuel emissions are decreasing the radiocarbon content through the release of 14C-depleted CO2. Here, we use the ECCO-v4 ocean state estimate to examine the changing nature of the air-sea flux of radiocarbon and its spatial distribution in the ocean in response to past and future CO2 emissions, the latter taken from the the Representative Concentration Pathway (RCP) database used in IPCC simulations. In line with previous studies we find that the large air-sea gradient of 14C induced by nuclear bomb testing led to rapid accumulation of radiocarbon in the surface ocean. Surface fluxes of 14C have considerably weakened over the past several decades and in some areas 14C is being returned to the atmosphere. As fossil fuel emissions continue to reduce the atmospheric 14C/C ratio (Δ14C), in most RCP scenarios the total ocean 14C inventory starts decreasing by 2030. With strong emissions, the Δ14C of surface waters is driven to increasingly negative values and in RCP 8.5 by 2100 much of the surface ocean has apparent radiocarbon ages in excess of 2000 years, with subtropical gyres more depleted in 14C than the Southern Ocean. Surface waters become significantly more negative in Δ14C than underlying waters. As a result, turning conventional tracer oceanography on its head, recently ventilated waters are characterized by more negative Δ14C values. Similar patterns can be expected for CFCs in the ocean as atmospheric concentrations decrease over the next several decades. Our results have a number of implications, notably for

Microflora distributions in paleosols: a method for calculating the validity of radiocarbon-dated surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahaney, W.C.; Boyer, M.G.

1986-08-01

Microflora (bacteria and fungi) distributions in several paleosols from Mount Kenya, East Africa, provide important information about contamination of buried soil horizons dated by radiocarbon. High counts of bacteria and fungi in buried soils provide evidence for contamination by plant root effects or ground water movement. Profiles with decreasing counts versus depth appear to produce internally consistent and accurate radiocarbon dates. Profiles with disjunct or bimodal distributions of microflora at various depths produce internally inconsistent chronological sequences of radiocarbon-dated buried surfaces. Preliminary results suggest that numbers up to 5 x 10/sup 2/ g/sup -1/ for bacteria in buried A horizonsmore » do not appear to affect the validity of /sup 14/C dates. Beyond this threshold value, contamination appears to produce younger dates, the difference between true age and /sup 14/C age increasing with the amount of microflora contamination.« less

Constraining the Stratosphere-Troposphere Exchange of Radiocarbon using AirCore 14CO2 Measurements

NASA Astrophysics Data System (ADS)

Chen, H.

2016-12-01

Radiocarbon (14C) plays an important role in the carbon cycle studies to understand both natural and anthropogenic carbon fluxes, but also in atmospheric chemistry to constrain hydroxyl radical (OH) concentrations in the atmosphere. Apart from the enormous 14C emissions from nuclear bomb testing in the 1950s and 1960s, radiocarbon is primarily produced in the upper atmosphere due to reactions of nitrogen nuclei with thermal neutrons that are induced by cosmic rays. 14C is quickly oxidized to 14CO, which is then further oxidized to 14CO2 by OH. To this end, better understanding the radiocarbon source is very useful to advance the use of radiocarbon for these applications. However, upper atmospheric 14C observations have been very sparse to constrain the magnitude and the location of the 14C production as well as the transport of radiocarbon from the stratosphere to the troposphere. Recently we have successfully made stratospheric 14CO2 measurements using AirCore samples from Sodankylä, Northern Finland, along with regular AirCore profiles of CO2, CH4, and CO since 2013. In this study, we calculate the stratosphere-troposphere exchange of 14C using the correlation between 14CO2 and N2O, and the estimated N2O loss rate. Besides this, we assess the impact of the mean age of air on 14CO2 profiles. Furthermore, we will evaluate the influence of different cosmogenic 14C production scenarios and the uncertainties in the OH field on the seasonal cycles of radiocarbon and on the stratosphere-troposphere exchange.

The radiocarbon reservoir age of the Chukchi Sea, Arctic Ocean

NASA Astrophysics Data System (ADS)

Pearce, C.; Gyllencreutz, R.; West, G.; O'Regan, M.; Jakobsson, M.

2017-12-01

Radiocarbon (14C) dating is the standard method for obtaining the age of marine sediments of Holocene and late Pleistocene age. For accurate calibrations, however, this tool relies on precise knowledge of the local radiocarbon reservoir age of the surface ocean, i.e. the regional difference (ΔR) from the average global marine calibration dataset. This parameter has become impossible to measure from modern mollusk samples because of 14C contamination from extensive testing of thermo-nuclear bombs in the second half of the twentieth century. The local reservoir age can thus only be calculated from the radiocarbon age of samples collected before AD 1950 or from sediment records containing absolute age markers, derived from e.g. tephrochronology or paleomagnetism. Knowledge of the marine reservoir age in the Arctic Ocean is extremely sparse, and relies on work by only a few studies. No information exists for the entire East Siberian Sea, and the Chukchi Sea is represented solely by sites along the Alaskan coast. Here we present new radiocarbon measurements on historical mollusk collections from the East Siberian and Chukchi margins. Our results show a clear and consistent signal of "old" Pacific Water in the Chukchi Sea with ΔR values around 450 years. Towards the East Siberian Sea the values drop as Pacific Water has decreased influence further away from the Bering Strait. Complementing the modern data, we also provide constraints on the reservoir age during the late Holocene. These are based on tephrochronology and high resolution analyses of paleomagnetic secular variation from a sediment archive from Herald Canyon, Chukchi Sea.

Discussion: Reporting and calibration of post-bomb 14C data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reimer, P J; Brown, T A; Reimer, R W

2004-10-11

The definitive paper by Stuiver and Polach (1977) established the conventions for reporting of {sup 14}C data for chronological and geophysical studies based on the radioactive decay of {sup 14}C in the sample since the year of sample death or formation. Several ways of reporting {sup 14}C activity levels relative to a standard were also established, but no specific instructions were given for reporting nuclear weapons testing (post-bomb) {sup 14}C levels in samples. Because the use of post-bomb {sup 14}C is becoming more prevalent in forensics, biology, and geosciences, a convention needs to be adopted. We advocate the use ofmore » fraction modern with a new symbol F{sup 14}C to prevent confusion with the previously used Fm, which may or may not have been fractionation corrected. We also discuss the calibration of post-bomb {sup 14}C samples and the available datasets and compilations, but do not give a recommendation for a particular dataset.« less

Optical Measurement of Radiocarbon below Unity Fraction Modern by Linear Absorption Spectroscopy.

PubMed

Fleisher, Adam J; Long, David A; Liu, Qingnan; Gameson, Lyn; Hodges, Joseph T

2017-09-21

High-precision measurements of radiocarbon ( 14 C) near or below a fraction modern 14 C of 1 (F 14 C ≤ 1) are challenging and costly. An accurate, ultrasensitive linear absorption approach to detecting 14 C would provide a simple and robust benchtop alternative to off-site accelerator mass spectrometry facilities. Here we report the quantitative measurement of 14 C in gas-phase samples of CO 2 with F 14 C < 1 using cavity ring-down spectroscopy in the linear absorption regime. Repeated analysis of CO 2 derived from the combustion of either biogenic or petrogenic sources revealed a robust ability to differentiate samples with F 14 C < 1. With a combined uncertainty of 14 C/ 12 C = 130 fmol/mol (F 14 C = 0.11), initial performance of the calibration-free instrument is sufficient to investigate a variety of applications in radiocarbon measurement science including the study of biofuels and bioplastics, illicitly traded specimens, bomb dating, and atmospheric transport.

Dating the End of the Greek Bronze Age: A Robust Radiocarbon-Based Chronology from Assiros Toumba

PubMed Central

Wardle, Kenneth; Higham, Thomas; Kromer, Bernd

2014-01-01

Over 60 recent analyses of animal bones, plant remains, and building timbers from Assiros in northern Greece form an unique series from the 14th to the 10th century BC. With the exception of Thera, the number of 14C determinations from other Late Bronze Age sites in Greece has been small and their contribution to chronologies minimal. The absolute dates determined for Assiros through Bayesian modelling are both consistent and unexpected, since they are systematically earlier than the conventional chronologies of southern Greece by between 70 and 100 years. They have not been skewed by reference to assumed historical dates used as priors. They support high rather than low Iron Age chronologies from Spain to Israel where the merits of each are fiercely debated but remain unresolved. PMID:25222862

Radiocarbon dating uncertainty and the reliability of the PEWMA method of time-series analysis for research on long-term human-environment interaction

PubMed Central

Carleton, W. Christopher; Campbell, David

2018-01-01

Statistical time-series analysis has the potential to improve our understanding of human-environment interaction in deep time. However, radiocarbon dating—the most common chronometric technique in archaeological and palaeoenvironmental research—creates challenges for established statistical methods. The methods assume that observations in a time-series are precisely dated, but this assumption is often violated when calibrated radiocarbon dates are used because they usually have highly irregular uncertainties. As a result, it is unclear whether the methods can be reliably used on radiocarbon-dated time-series. With this in mind, we conducted a large simulation study to investigate the impact of chronological uncertainty on a potentially useful time-series method. The method is a type of regression involving a prediction algorithm called the Poisson Exponentially Weighted Moving Average (PEMWA). It is designed for use with count time-series data, which makes it applicable to a wide range of questions about human-environment interaction in deep time. Our simulations suggest that the PEWMA method can often correctly identify relationships between time-series despite chronological uncertainty. When two time-series are correlated with a coefficient of 0.25, the method is able to identify that relationship correctly 20–30% of the time, providing the time-series contain low noise levels. With correlations of around 0.5, it is capable of correctly identifying correlations despite chronological uncertainty more than 90% of the time. While further testing is desirable, these findings indicate that the method can be used to test hypotheses about long-term human-environment interaction with a reasonable degree of confidence. PMID:29351329

Radiocarbon dating uncertainty and the reliability of the PEWMA method of time-series analysis for research on long-term human-environment interaction.

PubMed

Carleton, W Christopher; Campbell, David; Collard, Mark

2018-01-01

Statistical time-series analysis has the potential to improve our understanding of human-environment interaction in deep time. However, radiocarbon dating-the most common chronometric technique in archaeological and palaeoenvironmental research-creates challenges for established statistical methods. The methods assume that observations in a time-series are precisely dated, but this assumption is often violated when calibrated radiocarbon dates are used because they usually have highly irregular uncertainties. As a result, it is unclear whether the methods can be reliably used on radiocarbon-dated time-series. With this in mind, we conducted a large simulation study to investigate the impact of chronological uncertainty on a potentially useful time-series method. The method is a type of regression involving a prediction algorithm called the Poisson Exponentially Weighted Moving Average (PEMWA). It is designed for use with count time-series data, which makes it applicable to a wide range of questions about human-environment interaction in deep time. Our simulations suggest that the PEWMA method can often correctly identify relationships between time-series despite chronological uncertainty. When two time-series are correlated with a coefficient of 0.25, the method is able to identify that relationship correctly 20-30% of the time, providing the time-series contain low noise levels. With correlations of around 0.5, it is capable of correctly identifying correlations despite chronological uncertainty more than 90% of the time. While further testing is desirable, these findings indicate that the method can be used to test hypotheses about long-term human-environment interaction with a reasonable degree of confidence.

Dating of palaeomagnetic secular variation in Swedish varved lake sediments using radiocarbon wiggle-matching

NASA Astrophysics Data System (ADS)

Mellström, Anette; Nilsson, Andreas; Stanton, Tania; Muscheler, Raimund; Snowball, Ian

2013-04-01

Well-dated natural archives are crucial when investigating the timing between climate change and climate forcing. Annually laminated (varved) lake sediments, in particular, can provide valuable knowledge about past climatic and environmental conditions as the annual nature of the sediments enables the establishment of high-resolution archives. In addition, lake sediments can record variations in the Earth's magnetic field, which has the potential to be used as a dating validation technique if the palaeo-secular and -intensity curves are dated correctly. If individual and well-defined geomagnetic events can be dated accurately, they can then be used as isochrones, thereby allowing the synchronisation of different records. We therefore aim to date the "f" event, a late Holocene secular variation change, which is recorded in many sites in the northern hemisphere. Varved sites in Sweden have dated the "f" event to ~2700 cal. yrs BP. In order to constrain this date further, we have used the radiocarbon wiggle-matching method on a lake in central west Sweden, Kälksjön (Stanton et al., 2010), whose chronology has previously been validated using a number of complimentary dating methods. With the radiocarbon wiggle-matching technique, closely spaced samples are measured and matched to distinct wiggles in the radiocarbon calibration curve. The advantage of using varve-dated sediments is that it is possible to know the exact number of years between each sample, and therefore improve the initial age model. We compare the wiggle-match results of Kälksjön with results from a newly discovered varved lake sediment sequence in southern Sweden, Gyltigesjön. This comparison can provide information about magnetisation processes in sediments, such as the length of the palaeomagnetic lock-in delay. Stanton, T., Snowball, I., Zillén, L., Wastegård, S., 2010. Validating a Swedish varve chronology using radiocarbon, palaeomagnetic secular variation, lead pollution history and

Radiocarbon dating of American pika fecal pellets provides insights into population extirpations and climate refugia.

PubMed

Millar, Constance I; Heckman, Katherine; Swanston, Christopher; Schmidt, Karena; Westfall, Robert D; Delany, Diane L

The American pika (Ochotona princeps) has become a species of concern for its sensitivity to warm temperatures and potential vulnerability to global warming. We explored the value of radiocarbon dating of fecal pellets to address questions of population persistence and timing of site extirpation. Carbon was extracted from pellets collected at 43 locations in the western Great Basin, USA, including three known occupied sites and 40 sites of uncertain status at range margins or where previous studies indicated the species is vulnerable. We resolved calibrated dates with high precision (within several years), most of which fell in the period of the mid-late 20th century bomb curve. The two-sided nature of the bomb curve renders far- and near-side dates of equal probability, which are separated by one to four decades. We document methods for narrowing resolution to one age range, including stratigraphic analysis of vegetation collected from pika haypiles. No evidence was found for biases in atmospheric 14C levels due to fossil-derived or industrial CO2 contamination. Radiocarbon dating indicated that pellets can persist for >59 years; known occupied sites resolved contemporary dates. Using combined evidence from field observations and radiocarbon dating, and the Bodie Mountains as an example, we propose a historical biogeographic scenario for pikas in minor Great Basin mountain ranges adjacent to major cordillera, wherein historical climate variability led to cycles of extirpation and recolonization during alternating cool and warm centuries. Using this model to inform future dynamics for small ranges in biogeographic settings similar to the Bodie Mountains in California, extirpation of pikas appears highly likely under directional warming trends projected for the next century, even while populations in extensive cordillera (e.g., Sierra Nevada, Rocky Mountains, Cascade Range) are likely to remain viable due to extensive, diverse habitat and high connectivity.

High-precision radiocarbon dating and historical biblical archaeology in southern Jordan

PubMed Central

Levy, Thomas E.; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G.; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P.; Najjar, Mohammad; Tauxe, Lisa

2008-01-01

Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200–500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries the accepted IA chronology of Edom. Data from Khirbat en-Nahas, and the nearby site of Rujm Hamra Ifdan, demonstrate the centrality of industrial-scale metal production during those centuries traditionally linked closely to political events in Edom's 10th century BCE neighbor ancient Israel. Consequently, the rise of IA Edom is linked to the power vacuum created by the collapse of Late Bronze Age (LB, ca. 1300 BCE) civilizations and the disintegration of the LB Cypriot copper monopoly that dominated the eastern Mediterranean. The methodologies applied to the historical IA archaeology of the Levant have implications for other parts of the world where sacred and historical texts interface with the material record. PMID:18955702

Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus).

PubMed

Nielsen, Julius; Hedeholm, Rasmus B; Heinemeier, Jan; Bushnell, Peter G; Christiansen, Jørgen S; Olsen, Jesper; Ramsey, Christopher Bronk; Brill, Richard W; Simon, Malene; Steffensen, Kirstine F; Steffensen, John F

2016-08-12

The Greenland shark (Somniosus microcephalus), an iconic species of the Arctic Seas, grows slowly and reaches >500 centimeters (cm) in total length, suggesting a life span well beyond those of other vertebrates. Radiocarbon dating of eye lens nuclei from 28 female Greenland sharks (81 to 502 cm in total length) revealed a life span of at least 272 years. Only the smallest sharks (220 cm or less) showed signs of the radiocarbon bomb pulse, a time marker of the early 1960s. The age ranges of prebomb sharks (reported as midpoint and extent of the 95.4% probability range) revealed the age at sexual maturity to be at least 156 ± 22 years, and the largest animal (502 cm) to be 392 ± 120 years old. Our results show that the Greenland shark is the longest-lived vertebrate known, and they raise concerns about species conservation. Copyright © 2016, American Association for the Advancement of Science.

Associated terrestrial and marine fossils in the late-glacial Presumpscot Formation, southern Maine, USA, and the marine reservoir effect on radiocarbon ages

USGS Publications Warehouse

Thompson, W.B.; Griggs, C.B.; Miller, N.G.; Nelson, R.E.; Weddle, T.K.; Kilian, T.M.

2011-01-01

Excavations in the late-glacial Presumpscot Formation at Portland, Maine, uncovered tree remains and other terrestrial organics associated with marine invertebrate shells in a landslide deposit. Buds of Populus balsamifera (balsam poplar) occurred with twigs of Picea glauca (white spruce) in the Presumpscot clay. Tree rings in Picea logs indicate that the trees all died during winter dormancy in the same year. Ring widths show patterns of variation indicating responses to environmental changes. Fossil mosses and insects represent a variety of species and wet to dry microsites. The late-glacial environment at the site was similar to that of today's Maine coast. Radiocarbon ages of 14 tree samples are 11,907??31 to 11,650??5014C yr BP. Wiggle matching of dated tree-ring segments to radiocarbon calibration data sets dates the landslide occurrence at ca. 13,520+95/??20calyr BP. Ages of shells juxtaposed with the logs are 12,850??6514C yr BP (Mytilus edulis) and 12,800??5514C yr BP (Balanus sp.), indicating a marine reservoir age of about 1000yr. Using this value to correct previously published radiocarbon ages reduces the discrepancy between the Maine deglaciation chronology and the varve-based chronology elsewhere in New England. ?? 2011 University of Washington.

Associated terrestrial and marine fossils in the late-glacial Presumpscot Formation, southern Maine, USA, and the marine reservoir effect on radiocarbon ages

NASA Astrophysics Data System (ADS)

Thompson, Woodrow B.; Griggs, Carol B.; Miller, Norton G.; Nelson, Robert E.; Weddle, Thomas K.; Kilian, Taylor M.

2011-05-01

Excavations in the late-glacial Presumpscot Formation at Portland, Maine, uncovered tree remains and other terrestrial organics associated with marine invertebrate shells in a landslide deposit. Buds of Populus balsamifera (balsam poplar) occurred with twigs of Picea glauca (white spruce) in the Presumpscot clay. Tree rings in Picea logs indicate that the trees all died during winter dormancy in the same year. Ring widths show patterns of variation indicating responses to environmental changes. Fossil mosses and insects represent a variety of species and wet to dry microsites. The late-glacial environment at the site was similar to that of today's Maine coast. Radiocarbon ages of 14 tree samples are 11,907 ± 31 to 11,650 ± 50 14C yr BP. Wiggle matching of dated tree-ring segments to radiocarbon calibration data sets dates the landslide occurrence at ca. 13,520 + 95/-20 cal yr BP. Ages of shells juxtaposed with the logs are 12,850 ± 65 14C yr BP ( Mytilus edulis) and 12,800 ± 55 14C yr BP ( Balanus sp.), indicating a marine reservoir age of about 1000 yr. Using this value to correct previously published radiocarbon ages reduces the discrepancy between the Maine deglaciation chronology and the varve-based chronology elsewhere in New England.

Santorini eruption radiocarbon dated to 1627-1600 B.C.

PubMed

Friedrich, Walter L; Kromer, Bernd; Friedrich, Michael; Heinemeier, Jan; Pfeiffer, Tom; Talamo, Sahra

2006-04-28

Precise and direct dating of the Minoan eruption of Santorini (Thera) in Greece, a global Bronze Age time marker, has been made possible by the unique find of an olive tree, buried alive in life position by the tephra (pumice and ashes) on Santorini. We applied so-called radiocarbon wiggle-matching to a carbon-14 sequence of tree-ring segments to constrain the eruption date to the range 1627-1600 B.C. with 95.4% probability. Our result is in the range of previous, less precise, and less direct results of several scientific dating methods, but it is a century earlier than the date derived from traditional Egyptian chronologies.

Anchoring historical sequences using a new source of astro-chronological tie-points

NASA Astrophysics Data System (ADS)

Dee, Michael W.; Pope, Benjamin J. S.

2016-08-01

The discovery of past spikes in atmospheric radiocarbon activity, caused by major solar energetic particle events, has opened up new possibilities for high-precision chronometry. The two spikes, or Miyake Events, have now been widely identified in tree-rings that grew in the years 775 and 994 CE. Furthermore, all other plant material that grew in these years would also have incorporated the anomalously high concentrations of radiocarbon. Crucially, some plant-based artefacts, such as papyrus documents, timber beams and linen garments, can also be allocated to specific positions within long, currently unfixed, historical sequences. Thus, Miyake Events represent a new source of tie-points that could provide the means for anchoring early chronologies to the absolute timescale. Here, we explore this possibility, outlining the most expeditious approaches, the current challenges and obstacles, and how they might best be overcome.

Chronology and pedogenic effects of mid- to late-Holocene conversion of forests to pastures in the French western Pyrenees

Treesearch

David S. Leigh; Theodore L. Gragson; Michael R. Coughlan

2015-01-01

This paper presents a place-based examination of the timing and long-term pedogenic effects of human-induced forest to pasture conversion in the French western Pyrenees Mountains, Basque commune of Larrau. We analyzed colluvial stratigraphic sections to derive the chronology of landscape change using radiocarbon dating, charcoal concentrations, magnetic...

Age estimation in forensic sciences: application of combined aspartic acid racemization and radiocarbon analysis.

PubMed

Alkass, Kanar; Buchholz, Bruce A; Ohtani, Susumu; Yamamoto, Toshiharu; Druid, Henrik; Spalding, Kirsty L

2010-05-01

Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster because the age at death, birth date, and year of death as well as gender can guide investigators to the correct identity among a large number of possible matches. Traditional morphological methods used by anthropologists to determine age are often imprecise, whereas chemical analysis of tooth dentin, such as aspartic acid racemization, has shown reproducible and more precise results. In this study, we analyzed teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that aboveground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ((14)C), which has been carefully recorded over time. Forty-four teeth from 41 individuals were analyzed using aspartic acid racemization analysis of tooth crown dentin or radiocarbon analysis of enamel, and 10 of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R(2) = 0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 1.0 +/- 0.6 years. Aspartic acid racemization also showed a good precision with an overall absolute error of 5.4 +/- 4.2 years. Whereas radiocarbon analysis gives an estimated year of birth, racemization analysis indicates the chronological age of the individual at the time of death. We show how these methods in combination can also assist in the estimation of date of death of an unidentified victim. This strategy can be of significant assistance in forensic casework involving dead victim identification.

Radiocarbon Dating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchholz, B A

Radiocarbon dating can be used to determine the age of objects that contain components that were once alive. In the case of human remains, a radiocarbon date can distinguish between a crime scene and an archeological site. Documents, museum artifacts and art objects can be dated to determine if their age is correct for the historical context. A radiocarbon date does not confirm authenticity, but it can help identify a forgery.

Towards constraining the stratosphere-troposphere exchange of radiocarbon: strategies of stratospheric 14CO2 measurements using AirCore

NASA Astrophysics Data System (ADS)

Chen, Huilin; Paul, Dipayan; Meijer, Harro; Miller, John; Kivi, Rigel; Krol, Maarten

2016-04-01

Radiocarbon (14C) plays an important role in the carbon cycle studies to understand both natural and anthropogenic carbon fluxes, but also in atmospheric chemistry to constrain hydroxyl radical (OH) concentrations in the atmosphere. Apart from the enormous 14C emissions from nuclear bomb testing in the 1950s and 1960s, radiocarbon is primarily produced in the stratosphere due to the cosmogenic production. To this end, better understanding the stratospheric radiocarbon source is very useful to advance the use of radiocarbon for these applications. However, stratospheric 14C observations have been very limited so that there are large uncertainties on the magnitude and the location of the 14C production as well as the transport of radiocarbon from the stratosphere to the troposphere. Recently we have successfully made stratospheric 14C measurements using AirCore samples from Sodankylä, Northern Finland. AirCore is an innovative atmospheric sampling system, which passively collects atmospheric air samples into a long piece of coiled stainless steel tubing during the descent of a balloon flight. Due to the relatively low cost of the consumables, there is a potential to make such AirCore profiling in other parts of the world on a regular basis. In this study, we simulate the 14C in the atmosphere and assess the stratosphere-troposphere exchange of radiocarbon using the TM5 model. The Sodankylä radiocarbon measurements will be used to verify the performance of the model at high latitude. Besides this, we will also evaluate the influence of different cosmogenic 14C production scenarios and the uncertainties in the OH field on the seasonal cycles of radiocarbon and on the stratosphere-troposphere exchange, and based on the results design a strategy to set up a 14C measurement program using AirCore.

Forensic Seismology: constraints on terrorist bombings

NASA Astrophysics Data System (ADS)

Wallace, T. C.; Koper, K. D.

2002-05-01

Seismology has long been used as a tool to monitor and investigate explosions, both accidental and intentional. Seismic records can be used to provide a precise chronology of events, estimate the energy release in explosions and produce constraints to test various scenarios for the explosions. Truck bombs are a popular tool of terrorists, and at least two such attacks have been recorded seismically. On August 7, 1998 a truck bomb was detonated near the US embassy in Nairobi, Kenya. The bomb seriously damaging a dozen buildings, injuring more than 4000 people and causing 220 fatalities. The explosion was recorded on a short-period seismometer located north of the blast site; the blast seismogram contained body waves, Rayleigh waves and vibrations associated with the air blast. Modeling of the body and surfaces wave allowed an estimate of the origin time of the bombing, which it turn could be used as a constraint the timing of the air blasts. The speed of the air waves from an explosion depend on the air temperature and the size, or yield, of the explosion. In an effort to fully utilize the seismic recordings from such attacks, we analyzed the seismic records from a series of controlled truck bomb explosions carried out at White Sand Missile Range in New Mexico. We developed a new set of scaling laws that relate seismic and acoustic observations directly to the explosive mass (yield). These relationships give a yield of approximately 3000 kg of TNT equivalent for the Nairobi bomb. The terrorist bombing of the Murrah Federal Building in Oklahoma City in 1995 was also recorded on seismometers. One of these records showed 2 discrete surface wavetrains separated by approximately 10 seconds. Some groups seized on the seismic recordings as evidence that there were 2 explosions, and that the US government was actually behind the bombing. However, the USGS monitored the demolition of the remainder of the Murrah Building and showed that the collapse also produced 2 surface

Bombs and Bomb Threats in the School

ERIC Educational Resources Information Center

Starkey, David J.; Starkey, John D.

1977-01-01

Bombs and the threat of bombing can leave school personnel faced by an explosive hazard without knowledge of what to do. Therefore, a preplanned response is necessary. Discusses four major stages of dealing with bombs and bomb threats. (Author/RK)

Revised direct radiocarbon dating of the Vindija G1 Upper Paleolithic Neandertals.

PubMed

Higham, Tom; Ramsey, Christopher Bronk; Karavanić, Ivor; Smith, Fred H; Trinkaus, Erik

2006-01-17

The 1998/1999 direct dating of two Neandertal specimens from level G(1) of Vindija Cave in Croatia to approximately 28,000 and approximately 29,000 radiocarbon ((14)C) years ago has led to interpretations concerning the late survival of Neandertals in south-central Europe, patterns of interaction between Neandertals and in-dispersing early modern humans in Europe, and complex biocultural scenarios for the earlier phases of the Upper Paleolithic. Given improvements, particularly in sample pretreatment techniques for bone radiocarbon samples, especially ultrafiltration of collagen samples, these Vindija G(1) Neandertal fossils are redated to approximately 32,000-33,000 (14)C years ago and possibly earlier. These results and the recent redating of a number of purportedly old modern human skeletal remains in Europe to younger time periods highlight the importance of fine chronological control when studying this biocultural time period and the tenuous nature of monolithic scenarios for the establishment of modern humans and earlier phases of the Upper Paleolithic in Europe.

Holocene glacier chronology of the Southern Alps/New Zealand - a critical re-assessment based on geomorphological and glaciological principles

NASA Astrophysics Data System (ADS)

Winkler, Stefan

2017-04-01

The Southern Alps of New Zealand is one of few suitable study sites for the investigation of Holocene glacier chronologies in the mid-latitudinal Southern Hemisphere. As a result, several studies have been carried out during the past decades applying diverse approaches and using different numerical dating methods (Radiocarbon dating, terrestrial cosmogenic nuclide dating - TCND) or combined methods like Schmidt-hammer exposure-age dating (SHD) or weathering-rind thickness. The availability of a regional 10Be production curve has improved the calibration of TCND-ages and modern calibration programmes allow re-calculation of old, non-calibrated radiocarbon ages. Despite this progress and an increasing number of studies, there still remains considerable discrepancy if these studies are analysed in detail. And although the Southern Alps of New Zealand are included in more recent global reviews, the corresponding paragraphs are somehow biased towards few selected chronologies and an ostensible 'supremacy' of age information obtained by TCND. Reason for this practise is most likely a comparably high number of individual boulders precisely dated, but moraine ridges on those glacier forelands investigated have been primarily clustered on basis of boulder ages rather than on their geomorphological, sedimentological, and lithological properties. Detailed geomorphological investigation has, however, revealed that disregarding the latter mentioned creates artefacts in form of wrongly introduced advances within existing glacier chronologies alongside uncertainties caused by not paying attention to the concept of 'Little Ice Age'-type events (neoglacial events) and diverse glacier response times. In an attempt to resolve or at least reduce existing uncertainties and contribute towards a future representative regional Holocene glacier chronology for the Southern Alps, the most prominent existing chronologies have be re-assessed. Although the raw data of some studies needed at

Intercomparison of radiocarbon bomb pulse and 210Pb age models. A study in a peat bog core from North Poland

NASA Astrophysics Data System (ADS)

Piotrowska, Natalia; De Vleeschouwer, François; Sikorski, Jarosław; Pawlyta, Jacek; Fagel, Nathalie; Le Roux, Gaël; Pazdur, Anna

2010-04-01

Radiocarbon and 210Pb were measured on the uppermost 40 cm of a Wardenaar peat core retrieved from a Baltic raised bog at Słowińskie Błota (Pomerania, North Poland). This site is the subject of ongoing multiproxy studies covering the last 1300 years. Radiocarbon age model was constructed on the basis of 14 AMS dates obtained on selected Sphagnum spp. fragments, with use of P_Sequence tool. We present here a comparison of this model with the age model obtained using CRS model classically applied to 210Pb measurements.

Bomb Threats and Bomb Search Techniques.

ERIC Educational Resources Information Center

Department of the Treasury, Washington, DC.

This pamphlet explains how to be prepared and plan for bomb threats and describes procedures to follow once a call has been received. The content covers (1) preparation for bomb threats, (2) evacuation procedures, (3) room search methods, (4) procedures to follow once a bomb has been located, and (5) typical problems that search teams will…

Chronology of Postglacial Eruptive Activity and Calculation of Eruption Probabilities for Medicine Lake Volcano, Northern California

USGS Publications Warehouse

Nathenson, Manuel; Donnelly-Nolan, Julie M.; Champion, Duane E.; Lowenstern, Jacob B.

2007-01-01

Medicine Lake volcano has had 4 eruptive episodes in its postglacial history (since 13,000 years ago) comprising 16 eruptions. Time intervals between events within the episodes are relatively short, whereas time intervals between the episodes are much longer. An updated radiocarbon chronology for these eruptions is presented that uses paleomagnetic data to constrain the choice of calibrated ages. This chronology is used with exponential, Weibull, and mixed-exponential probability distributions to model the data for time intervals between eruptions. The mixed exponential distribution is the best match to the data and provides estimates for the conditional probability of a future eruption given the time since the last eruption. The probability of an eruption at Medicine Lake volcano in the next year from today is 0.00028.

Precise chronologies of Holocene glacial culminations in the Cordillera Vilcabamba of southern Peru

NASA Astrophysics Data System (ADS)

Licciardi, J. M.; Schaefer, J. M.; Schweinsberg, A. D.

2012-12-01

Records of past fluctuations in climatically sensitive tropical mountain glaciers are among the best indicators of regional paleoclimatic trends and controls. The majority of the world's present-day tropical glaciers are found in the Peruvian Andes, but accurate and precise chronologies of past glacial activity in this region remain relatively scarce, particularly during the Holocene. Here we present ~50 new 10Be exposure ages derived from boulders on well-preserved moraine successions in several glaciated drainages in the Cordillera Vilcabamba of southern Peru (13°20'S latitude). The new results suggest that prominent moraines in these valleys are correlative with previously published moraine ages near Nevado Salcantay in this range (Licciardi et al., 2009), but also expand on the initial surface exposure chronologies to reveal additional periods of glacier stabilization not found in previous work. A provisional composite chronology that merges the new and previously obtained moraine ages indicates at least five discrete glacial culminations from the Lateglacial to the late Holocene. Forthcoming 10Be ages from an additional ~50 samples collected from moraine boulders will increase the precision and completeness of the Vilcabamba moraine chronologies. Basal radiocarbon ages are being developed from bog and lake sediments in stratigraphic contact with the 10Be-dated moraines. These new 14C age data will help constrain the local cosmogenic 10Be production rate, thereby increasing the accuracy of the 10Be chronologies.

Bomb-14C Peak in the North Pacific Recorded in Long-Lived Bivalve Shells (Mercenaria stimpsoni)

NASA Astrophysics Data System (ADS)

Kubota, Kaoru; Shirai, Kotaro; Murakami-Sugihara, Naoko; Seike, Koji; Minami, Masayo; Nakamura, Toshio; Tanabe, Kazushige

2018-04-01

The excess radiocarbon produced by nuclear bomb testing in the atmosphere in the 1950s-1960s (bomb-14C) is used as a tracer in the surface ocean, extending our understanding of geophysics and biogeochemical cycles. However, there is no bomb-14C record for the high-latitude western North Pacific Ocean because of the paucity of long-lived marine calcifying organisms equivalent to reef-building corals. The shells of Stimpson's hard clam, Mercenaria stimpsoni, potentially provide such a record because the clam's lifespan is very long (>100 years). We analyzed 14C in six live-caught M. stimpsoni shells from the western North Pacific (39.4°N, 142°E) and report, for the first time, the bomb-14C record with robust calendar ages based on annual growth increments. The value was constant in 1934-1952 (Δ14C = -66‰), with a sudden increase in 1959, a peak in 1974 (107‰), which was 60‰ lower than that of the Kuroshio Current, a gradual decline after 1974, and a current value of 16-18‰, which is ˜10‰ higher than the atmospheric value. The bomb-14C values are between the Kuroshio Current (the northwestern subtropical gyre) and Oyashio Current (the Western Subarctic Gyre) values, suggesting that the Tsugaru Current, downstream from the Kuroshio Current, mixes with the Oyashio Current after passing through Tsugaru Strait.

Chronometric investigations of the Middle to Upper Paleolithic transition in the Zagros Mountains using AMS radiocarbon dating and Bayesian age modelling.

PubMed

Becerra-Valdivia, Lorena; Douka, Katerina; Comeskey, Daniel; Bazgir, Behrouz; Conard, Nicholas J; Marean, Curtis W; Ollé, Andreu; Otte, Marcel; Tumung, Laxmi; Zeidi, Mohsen; Higham, Thomas F G

2017-08-01

The Middle to Upper Paleolithic transition is often linked with a bio-cultural shift involving the dispersal of modern humans outside of Africa, the concomitant replacement of Neanderthals across Eurasia, and the emergence of new technological traditions. The Zagros Mountains region assumes importance in discussions concerning this period as its geographic location is central to all pertinent hominin migration areas, pointing to both east and west. As such, establishing a reliable chronology in the Zagros Mountains is crucial to our understanding of these biological and cultural developments. Political circumstance, coupled with the poor preservation of organic material, has meant that a clear chronological definition of the Middle to Upper Paleolithic transition for the Zagros Mountains region has not yet been achieved. To improve this situation, we have obtained new archaeological samples for AMS radiocarbon dating from three sites: Kobeh Cave, Kaldar Cave, and Ghār-e Boof (Iran). In addition, we have statistically modelled previously published radiocarbon determinations for Yafteh Cave (Iran) and Shanidar Cave (Iraqi Kurdistan), to improve their chronological resolution and enable us to compare the results with the new dataset. Bayesian modelling results suggest that the onset of the Upper Paleolithic in the Zagros Mountains dates to 45,000-40,250 cal BP (68.2% probability). Further chronometric data are required to improve the precision of this age range. Copyright © 2017 Elsevier Ltd. All rights reserved.

Age estimation in forensic sciences: Application of combined aspartic acid racemization and radiocarbon analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alkass, K; Buchholz, B A; Ohtani, S

Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster, since the age at death, birth date and year of death, as well as gender, can guide investigators to the correct identity among a large number of possible matches. Traditional morphological methods used by anthropologists to determine age are often imprecise, whereas chemical analysis of tooth dentin, such as aspartic acid racemization has shown reproducible and more precise results. In this paper we analyze teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbonmore » analysis is that above-ground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ({sup 14}C) which have been carefully recorded over time. Forty-four teeth from 41 individuals were analyzed using aspartic acid racemization analysis of tooth crown dentin or radiocarbon analysis of enamel and ten of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R2=0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 0.6 {+-} 04 years. Aspartic acid racemization also showed a good precision with an overall absolute error of 5.4 {+-} 4.2 years. Whereas radiocarbon analysis gives an estimated year of birth, racemization analysis indicates the chronological age of the individual at the time of death. We show how these methods in combination can also assist in the estimation of date of death of an unidentified victim. This strategy can be of significant assistance in forensic casework involving dead victim identification.« less

Re-Emergence of Excess Bomb Radiocarbon in Upwelling Waters with High-Latitude Origins

NASA Astrophysics Data System (ADS)

Lindsay, C. M.; Lehman, S.

2016-02-01

The quantity of radiocarbon (14C) in the atmosphere was nearly doubled by nuclear weapons testing in the 1960s. Since then, the terrestrial biosphere and the ocean have absorbed most of the excess 14C from the atmosphere, although atmospheric radiocarbon activity (∆14C) continues to decline due to ongoing emissions of 14C-free CO2 from combustion of fossil fuels. The large transient decline in atmospheric ∆14C combined with gas exchange at the surface and spatially variable time scales of ocean mixing have led to large ∆14C gradients in the surface ocean between upwelling- and downwelling-dominated regions. These gradients continue to evolve over time. We examine the rate of change of surface ocean ∆14C between CLIVAR (2000-2011) and WOCE era (1990s) or other slightly earlier (1980s) datasets and find spatial patterns that reveal mixing between 14C-enriched mode waters, 14C-depleted deep waters and surface waters that are well-equilibrated with the atmosphere. The ∆14C of mode water reaching equatorial upwelling regions has increased between the WOCE and CLIVAR time periods, and the greater contribution of 14C to the low-latitude surface ocean appears to have significantly offset the ∆14C decline otherwise imparted by air-sea gas exchange with the atmosphere. Consequently, ∆14C gradients between low-latitude upwelling regions and gyre centers have weakened proportionally more than between gyre centers and regions where pre-industrial water still upwells, such as the Southern Ocean. Properly accounting for the re-emergence of water with post-industrial characteristics is important to constrain earth system models that seek to explain DIC, pH and other anthropogenically perturbed tracers in the surface ocean. Because of the history of ∆14C in the atmosphere, ocean ∆14C is a useful tracer for this purpose.

Cosmic ray event in 994 C.E. recorded in radiocarbon from Danish oak

NASA Astrophysics Data System (ADS)

Fogtmann-Schulz, A.; Østbø, S. M.; Nielsen, S. G. B.; Olsen, J.; Karoff, C.; Knudsen, M. F.

2017-08-01

We present measurements of radiocarbon in annual tree rings from the time period 980-1006 Common Era (C.E.), hereby covering the cosmic ray event in 994 C.E. The new radiocarbon record from Danish oak is based on both earlywood and latewood fractions of the tree rings, which makes it possible to study seasonal variations in 14C production. The measurements show a rapid increase of ˜10‰ from 993 to 994 C.E. in latewood, followed by a modest decline and relatively high values over the ensuing ˜10 years. This rapid increase occurs from 994 to 995 C.E. in earlywood, suggesting that the cosmic ray event most likely occurred during the period between April and June 994 C.E. Our new record from Danish oak shows strong agreement with existing Δ14C records from Japan, thus supporting the hypothesis that the 994 C.E. cosmic ray event was uniform throughout the Northern Hemisphere and therefore can be used as an astrochronological tie point to anchor floating chronologies of ancient history.

The chronology of reindeer hunting on Norway's highest ice patches

PubMed Central

Pilø, Lars; Finstad, Espen; Ramsey, Christopher Bronk; Martinsen, Julian Robert Post; Nesje, Atle; Solli, Brit; Wangen, Vivian; Callanan, Martin

2018-01-01

The melting of perennial ice patches globally is uncovering a fragile record of alpine activity, especially hunting and the use of mountain passes. When rescued by systematic fieldwork (glacial archaeology), this evidence opens an unprecedented window on the chronology of high-elevation activity. Recent research in Jotunheimen and surrounding mountain areas of Norway has recovered over 2000 finds—many associated with reindeer hunting (e.g. arrows). We report the radiocarbon dates of 153 objects and use a kernel density estimation (KDE) method to determine the distribution of dated events from ca 4000 BCE to the present. Interpreted in light of shifting environmental, preservation and socio-economic factors, these new data show counterintuitive trends in the intensity of reindeer hunting and other high-elevation activity. Cold temperatures may sometimes have kept humans from Norway's highest elevations, as expected based on accessibility, exposure and reindeer distributions. In times of increasing demand for mountain resources, however, activity probably continued in the face of adverse or variable climatic conditions. The use of KDE modelling makes it possible to observe this patterning without the spurious effects of noise introduced by the discrete nature of the finds and the radiocarbon calibration process. PMID:29410869

The role of inter-comparisons in radiocarbon quality assurance

NASA Astrophysics Data System (ADS)

Scott, Marian; Cook, Gordon; Naysmith, Philip

2016-04-01

Radiocarbon dating is used widely in many geochronology projects as a basis for the creation and testing of chronological constructs. Radiocarbon measurements are by their nature complex and the degree of sample pre-treatment varies considerably depending on the material. Within the UK and Europe, there are a number of well-established laboratories and increasingly, scientists are not just commissioning new dates, but also using statistical modelling of assemblages of dates, perhaps measured in different laboratories, to provide formal date estimates for their investigations. The issue of comparability of measurements (and thus bias, accuracy and precision of measurement) from the diverse laboratories is one which has been the focus of some attention both within the 14C community and the wider user communities for some time. As a result of this but also as part of laboratory benchmarking and quality assurance, the 14C community has undertaken a wide-scale, far-reaching and evolving programme of inter-comparisons, to the benefit of laboratories and users alike. This paper presents the results from the most recent exercise SIRI. The objectives of SIRI included, through choice of material, to contribute to the discussion concerning laboratory offsets and error multipliers in the context of IntCal (the International Calibration Programme) and to gain a better understanding of differences in background derived from a range of infinite age material types.

50 Years And 400 Radiocarbon Measurements Since 1959: What Has The “Bomb Spike” Taught Us About Soil C Dynamics In New Zealand Soils?

NASA Astrophysics Data System (ADS)

Baisden, W. T.; Parfitt, R. L.; Ross, C.

2009-12-01

broadly, the large database of radiocarbon measurements also creates opportunities to quantify carbon turnover and transport as a function of soil depth, and in non-steady state soil systems where the C stocks are known to be changing. The Egmont loam (Allophanic) and Tokomaru silt loam (non-Allophanic) showed different rates of "bomb-14C" incorporation under similar climate and land use.

Global Peak in Atmospheric Radiocarbon Provides a Potential Definition for the Onset of the Anthropocene Epoch in 1965.

PubMed

Turney, Chris S M; Palmer, Jonathan; Maslin, Mark A; Hogg, Alan; Fogwill, Christopher J; Southon, John; Fenwick, Pavla; Helle, Gerhard; Wilmshurst, Janet M; McGlone, Matt; Bronk Ramsey, Christopher; Thomas, Zoë; Lipson, Mathew; Beaven, Brent; Jones, Richard T; Andrews, Oliver; Hua, Quan

2018-02-19

Anthropogenic activity is now recognised as having profoundly and permanently altered the Earth system, suggesting we have entered a human-dominated geological epoch, the 'Anthropocene'. To formally define the onset of the Anthropocene, a synchronous global signature within geological-forming materials is required. Here we report a series of precisely-dated tree-ring records from Campbell Island (Southern Ocean) that capture peak atmospheric radiocarbon ( 14 C) resulting from Northern Hemisphere-dominated thermonuclear bomb tests during the 1950s and 1960s. The only alien tree on the island, a Sitka spruce (Picea sitchensis), allows us to seasonally-resolve Southern Hemisphere atmospheric 14 C, demonstrating the 'bomb peak' in this remote and pristine location occurred in the last-quarter of 1965 (October-December), coincident with the broader changes associated with the post-World War II 'Great Acceleration' in industrial capacity and consumption. Our findings provide a precisely-resolved potential Global Stratotype Section and Point (GSSP) or 'golden spike', marking the onset of the Anthropocene Epoch.

Insights into soil carbon dynamics across climatic and geologic gradients from temporally-resolved radiocarbon measurements

NASA Astrophysics Data System (ADS)

van der Voort, T. S.; Hagedorn, F.; Mannu, U.; Walthert, L.; McIntyre, C.; Eglinton, T. I.

2016-12-01

Soil carbon constitutes the largest terrestrial reservoir of organic carbon, and therefore quantifying soil organic matter dynamics (carbon turnover, stocks and fluxes) across spatial gradients is essential for an understanding of the carbon cycle and the impacts of global change. In particular, links between soil carbon dynamics and different climatic and compositional factors remains poorly understood. Radiocarbon constitutes a powerful tool for unraveling soil carbon dynamics. Temporally-resolved radiocarbon measurements, which take advantage of "bomb-radiocarbon"-driven changes in atmospheric 14C, enable further constraints to be placed on C turnover times. These in turn can yield more precise flux estimates for both upper and deeper soil horizons. This project combines bulk radiocarbon measurements on a suite of soil profiles spanning strong climatic (MAT 1.3-9.2°C, MAP 600 to 2100 mm m-2y-1) and geologic gradients with a more in-depth approach for a subset of locations. For this subset, temporal and carbon-fraction specific radiocarbon data has been acquired for both topsoil and deeper soils. These well-studied sites are part of the Long-Term Forest Ecosystem Research (LWF) program of the Swiss Federal Institute for Forest, Snow and Landscape research (WSL). Resulting temporally-resolved turnover estimates are coupled to carbon stocks, fluxes across this wide range of forest ecosystems and are examined in the context of environmental drivers (temperature, precipitation, primary production and soil moisture) as well as composition (sand, silt and clay content). Statistical analysis on the region-scale - correlating radiocarbon signature with climatic variables such as temperature, precipitation, primary production and elevation - indicates that composition rather than climate is a key driver of ­­Δ14C signatures. Estimates of carbon turnover, stocks and fluxes derived from temporally-resolved measurements highlight the pivotal role of soil moisture as a

Italian Bombs & Fuzes

DTIC Science & Technology

1948-06-01

document states that the practice of galvanising aircraft bombs has ceased, and that a protective coat of paint is now used instead. These colourings...that the Italians are still in possession of large stocks of galvanised bombs. SECTION I CHEMICAL WARFARE BOMBS No. C.W. bombs have yet been

Using tephra layers as absolute and relative chronological markers: an example from Lake Suigetsu, Japan

NASA Astrophysics Data System (ADS)

Smith, V.; Albert, P. G.; Staff, R.; Mark, D. F.; Bronk Ramsey, C.; Nakagawa, T.

2014-12-01

The Lake Suigetsu cores (SG06 and SG14) from Honshu Island, central Japan, provide a high-resolution paleoenvironmental record for the last ~200 kyrs. The composite record is ~85 m-long and it contains numerous tephras, more than 35 visible and numerous non-visible layers (cryptotephra). The major and trace element glass chemistry of these tephras allows the layers to be correlated to specific eruptions and tephra layers in other archives [1]. The record preserves large eruptions from volcanoes from Kyushu, Honshu, South Korea, and smaller explosive events from more proximal volcanoes, Daisen and Sanbe. The Lake Suigetsu has a very detailed varve and radiocarbon chronology [2] that has been exploited to provide precise ages for the tephra layers from the last 50 kyrs [1]. These ages can constrain the tempo of volcanic activity, and the age models of other sedimentary (paleoenvironmental and archaeological) records that contain the tephra. The deeper parts of the Suigetsu core are not continuosly annually laminated and are outside the radiocarbon timeframe and therefore do not have a well constrined chronology. The tephra layers can be used to provide an absolute chronology as eruption deposits from South Korea, Daisen and Sanbe often contain K-rich crystal phases, which can be dated using 40Ar/39Ar methods. Correlating these distal tephra layers in Lake Suigetsu to proximal deposits, using the glass chemistry, is essential as large crystals are required to obtain precise 40Ar/39Ar ages and these are only abundant in the coarser proximal deposits [3, 4]. These widespread marker layers can be also be used for relative chronology. Identifying the same tephras in disparate high-resolution archives allows them to be directly compared so that leads and lags in paleoclimate can be identified on the regional to continental scale, providing some insight into the fundamental drivers of the Earth's climate system. References: [1] Smith et al. (2013) Quaternary Science Reviews

High-precision radiocarbon dating of political collapse and dynastic origins at the Maya site of Ceibal, Guatemala

PubMed Central

Inomata, Takeshi; Triadan, Daniela; MacLellan, Jessica; Burham, Melissa; Aoyama, Kazuo; Palomo, Juan Manuel; Yonenobu, Hitoshi; Pinzón, Flory; Nasu, Hiroo

2017-01-01

The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the Middle Preclassic Period through the Terminal Classic (1000 BC to AD 950). The Ceibal-Petexbatun Archaeological Project has been conducting archaeological investigations at this site since 2005 and has obtained 154 radiocarbon dates, which represent the largest collection of radiocarbon assays from a single Maya site. The Bayesian analysis of these dates, combined with a detailed study of ceramics, allowed us to develop a high-precision chronology for Ceibal. Through this chronology, we traced the trajectories of the Preclassic collapse around AD 150–300 and the Classic collapse around AD 800–950, revealing similar patterns in the two cases. Social instability started with the intensification of warfare around 75 BC and AD 735, respectively, followed by the fall of multiple centers across the Maya lowlands around AD 150 and 810. The population of Ceibal persisted for some time in both cases, but the center eventually experienced major decline around AD 300 and 900. Despite these similarities in their diachronic trajectories, the outcomes of these collapses were different, with the former associated with the development of dynasties centered on divine rulership and the latter leading to their downfalls. The Ceibal dynasty emerged during the period of low population after the Preclassic collapse, suggesting that this dynasty was placed under the influence from, or by the direct intervention of, an external power. PMID:28115691

High-precision radiocarbon dating of political collapse and dynastic origins at the Maya site of Ceibal, Guatemala.

PubMed

Inomata, Takeshi; Triadan, Daniela; MacLellan, Jessica; Burham, Melissa; Aoyama, Kazuo; Palomo, Juan Manuel; Yonenobu, Hitoshi; Pinzón, Flory; Nasu, Hiroo

2017-02-07

The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the Middle Preclassic Period through the Terminal Classic (1000 BC to AD 950). The Ceibal-Petexbatun Archaeological Project has been conducting archaeological investigations at this site since 2005 and has obtained 154 radiocarbon dates, which represent the largest collection of radiocarbon assays from a single Maya site. The Bayesian analysis of these dates, combined with a detailed study of ceramics, allowed us to develop a high-precision chronology for Ceibal. Through this chronology, we traced the trajectories of the Preclassic collapse around AD 150-300 and the Classic collapse around AD 800-950, revealing similar patterns in the two cases. Social instability started with the intensification of warfare around 75 BC and AD 735, respectively, followed by the fall of multiple centers across the Maya lowlands around AD 150 and 810. The population of Ceibal persisted for some time in both cases, but the center eventually experienced major decline around AD 300 and 900. Despite these similarities in their diachronic trajectories, the outcomes of these collapses were different, with the former associated with the development of dynasties centered on divine rulership and the latter leading to their downfalls. The Ceibal dynasty emerged during the period of low population after the Preclassic collapse, suggesting that this dynasty was placed under the influence from, or by the direct intervention of, an external power.

Insights into soil carbon dynamics across climatic and geologic gradients from time-series and fraction-specific radiocarbon analysis

NASA Astrophysics Data System (ADS)

van der Voort, Tessa Sophia; Hagedorn, Frank; Zell, Claudia; McIntyre, Cameron; Eglinton, Tim

2016-04-01

Understanding the interaction between soil organic matter (SOM) and climatic, geologic and ecological factors is essential for the understanding of potential susceptibility and vulnerability to climate and land use change. Radiocarbon constitutes a powerful tool for unraveling SOM dynamics and is increasingly used in studies of carbon turnover. The complex and inherently heterogeneous nature of SOM renders it challenging to assess the processes that govern SOM stability by solely looking at the bulk signature on a plot-scale level. This project combines bulk radiocarbon measurements on a regional-scale spanning wide climatic and geologic gradients with a more in-depth approach for a subset of locations. For this subset, time-series and carbon pool-specific radiocarbon data has been acquired for both topsoil and deeper soils. These well-studied sites are part of the Long-Term Forest Ecosystem Research (LWF) program of the Swiss Federal Institute for Forest, Snow and Landscape research (WSL). Statistical analysis was performed to examine relationships of radiocarbon signatures with variables such as temperature, precipitation and elevation. Bomb-curve modeling was applied determine carbon turnover using time-series data. Results indicate that (1) there is no significant correlation between Δ14C signature and environmental conditions except a weak positive correlation with mean annual temperature, (2) vertical gradients in Δ14C signatures in surface and deeper soils are highly similar despite covering disparate soil-types and climatic systems, and (3) radiocarbon signatures vary significantly between time-series samples and carbon pools. Overall, this study provides a uniquely comprehensive dataset that allows for a better understanding of links between carbon dynamics and environmental settings, as well as for pool-specific and long-term trends in carbon (de)stabilization.

Forensic applications of 14C at CIRCE

NASA Astrophysics Data System (ADS)

Marzaioli, F.; Fiumano, V.; Capano, M.; Passariello, I.; Cesare, N. De.; Terrasi, F.

2011-12-01

The decreasing trend of the radiocarbon pulse produced during the atmospheric tests of nuclear weapons (bomb-carbon) coupled with high sensitivity accelerator mass spectrometry (AMS) measurements, drastically increased the precision of radiocarbon age determinations since the second part of the sixties, allowing the application of radiocarbon AMS to a wide range of studies previously not directly involving conventional radiocarbon dating (i.e. food authenticity, forensic, biochemistry). In the framework of authenticity evaluation of artworks, high precision radiocarbon ( 14C) AMS measurements (Δ R/ R < 0.3%) reduce the conventional uncertainty of the dating to few decades, allowing precise age estimation of materials containing carbon (C). The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) during its activity on AMS 14C dating achieved high precision measurements opening the opportunity to these kinds of applications. This paper presents the main results obtained from radiocarbon measurements on a set of bone samples analyzed for the determination of the post-mortem interval in the framework of an unsolved case investigated by the Rome prosecutor office. The chronological characterization of the wooden support of the "Acerenza portrait" is also presented with the aim to evaluate its age and to further investigate the possibility to attribute this artwork to Leonardo da Vinci. Bomb- 14C dating on the lipid and collagen fractions of bones allows the evaluation of the year of the death of the individuals by means of ad hoc calibration data sheet with the typical few years precision and difference between collagen apparent age and the year of death appeared in agreement with the age of one individual estimated by dating of tooth collagen. Conventional radiocarbon dating on both wood and wood extracted cellulose leads to an estimation of the portrait wood board age (2σ) of 1459-1524 AD (57% relative probability), 1571-1631 AD interval (42

On the Chronological Structure of the Solutrean in Southern Iberia

PubMed Central

Cascalheira, João; Bicho, Nuno

2015-01-01

The Solutrean techno-complex has gained particular significance over time for representing a clear demographic and techno-typological deviation from the developments occurred during the course of the Upper Paleolithic in Western Europe. Some of Solutrean’s most relevant features are the diversity and techno-typological characteristics of the lithic armatures. These have been recurrently used as pivotal elements in numerous Solutrean-related debates, including the chronological organization of the techno-complex across Iberia and Southwestern France. In Southern Iberia, patterns of presence and/or absence of specific point types in stratified sequences tend to validate the classical ordering of the techno-complex into Lower, Middle and Upper phases, although some evidence, namely radiocarbon determinations, have not always been corroborative. Here we present the first comprehensive analysis of the currently available radiocarbon data for the Solutrean in Southern Iberia. We use a Bayesian statistical approach from 13 stratified sequences to compare the duration, and the start and end moments of each classic Solutrean phase across sites. We conclude that, based on the current data, the traditional organization of the Solutrean cannot be unquestionably confirmed for Southern Iberia, calling into doubt the status of the classically-defined type-fossils as precise temporal markers. PMID:26355459

Radiocarbon Dating, Memories, and Hopes

DOE R&D Accomplishments Database

Libby, W. F.

1972-10-01

The history of radiocarbon dating from 1939 to the present is reviewed. The basic principles of radiocarbon dating are that cosmic rays make living things radioactive with {sup 14}C to a certain level fixed by the environment and that at death the intake of food stops so no replenishment of the {sup 14}C steadily lost by the immutable decay occurs. Therefore measurement of the degree of decay gives the time lapse since death, i.e., the radiocarbon age. The equipment developed and experiments performed to measure the specific activity of specimens to be dated are described. The results obtained by world-wide experimenters are discussed. These showed that on simultaneity radiocarbon dating is apparently reliable but that absolute dates may be incorrect by as much as 600 to 700 y. The value of radiocarbon dating to archaeologists, geologists, climatologists, and historians is stressed. (LCL)

The Remarkable Metrological History of Radiocarbon Dating [II].

PubMed

Currie, Lloyd A

2004-01-01

This article traces the metrological history of radiocarbon, from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that have brought (14)C measurement from a crude, bulk [8 g carbon] dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for "molecular dating" at the 10 µg to 100 µg level. The metrological advances led to opportunities and surprises, such as the non-monotonic dendrochronological calibration curve and the "bomb effect," that gave rise to new multidisciplinary areas of application, ranging from archaeology and anthropology to cosmic ray physics to oceanography to apportionment of anthropogenic pollutants to the reconstruction of environmental history. Beyond the specific topic of natural (14)C, it is hoped that this account may serve as a metaphor for young scientists, illustrating that just when a scientific discipline may appear to be approaching maturity, unanticipated metrological advances in their own chosen fields, and unanticipated anthropogenic or natural chemical events in the environment, can spawn new areas of research having exciting theoretical and practical implications.

The Remarkable Metrological History of Radiocarbon Dating [II

PubMed Central

Currie, Lloyd A.

2004-01-01

This article traces the metrological history of radiocarbon, from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that have brought 14C measurement from a crude, bulk [8 g carbon] dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for “molecular dating” at the 10 µg to 100 µg level. The metrological advances led to opportunities and surprises, such as the non-monotonic dendrochronological calibration curve and the “bomb effect,” that gave rise to new multidisciplinary areas of application, ranging from archaeology and anthropology to cosmic ray physics to oceanography to apportionment of anthropogenic pollutants to the reconstruction of environmental history. Beyond the specific topic of natural 14C, it is hoped that this account may serve as a metaphor for young scientists, illustrating that just when a scientific discipline may appear to be approaching maturity, unanticipated metrological advances in their own chosen fields, and unanticipated anthropogenic or natural chemical events in the environment, can spawn new areas of research having exciting theoretical and practical implications. PMID:27366605

Radiocarbon and stable carbon isotope compositions of chemically fractionated soil organic matter in a temperate-zone forest.

PubMed

Koarashi, Jun; Iida, Takao; Asano, Tomohiro

2005-01-01

To better understand the role of soil organic matter in terrestrial carbon cycle, carbon isotope compositions in soil samples from a temperate-zone forest were measured for bulk, acid-insoluble and base-insoluble organic matter fractions separated by a chemical fractionation method. The measurements also made it possible to estimate indirectly radiocarbon ((14)C) abundances of acid- and base-soluble organic matter fractions, through a mass balance of carbon among the fractions. The depth profiles of (14)C abundances showed that (1) bomb-derived (14)C has penetrated the first 16cm mineral soil at least; (2) Delta(14)C values of acid-soluble organic matter fraction are considerably higher than those of other fractions; and (3) a significant amount of the bomb-derived (14)C has been preserved as the base-soluble organic matter around litter-mineral soil boundary. In contrast, no or little bomb-derived (14)C was observed for the base-insoluble fraction in all sampling depths, indicating that this recalcitrant fraction, accounting for approximately 15% of total carbon in this temperate-zone forest soil, plays a role as a long-term sink in the carbon cycle. These results suggest that bulk soil organic matter cannot provide a representative indicator as a source or a sink of carbon in soil, particularly on annual to decadal timescales.

Radiocarbon dating the late Middle Paleolithic and the Aurignacian of the Swabian Jura.

PubMed

Conard, Nicholas J; Bolus, Michael

2008-11-01

Many lines of evidence point to the period between roughly 40 and 30 ka BP as the period in which modern humans arrived in Europe and displaced the indigenous Neandertal populations. At the same time, many innovations associated with the Upper Paleolithic--including new stone and organic technologies, use of personal ornaments, figurative art, and musical instruments--are first documented in the European archaeological record. Dating the events of this period is challenging for several reasons. In the period about six to seven radiocarbon half-lives ago, variable preservation, pre-treatment, and sample preparation can easily lead to a lack of reproducibility between samples and laboratories. A range of biological, cultural, and geological processes can lead to mixing of archaeological strata and their contents. Additionally, some data sets point to this period as a time of significant spikes in levels of atmospheric radiocarbon. This paper assesses these questions in the context of the well-excavated and intensively studied caves of Geissenklösterle and Hohle Fels in the Swabian Jura of southwestern Germany. We conclude that variable atmospheric radiocarbon production contributes to the problems of dating the late Middle Paleolithic and the early Upper Paleolithic. To help establish a reliable chronology for the Swabian Aurignacian, we are beginning to focus our dating program on short-lived, stratigraphically secure features to see if they yield reproducible results. This approach may help to test competing explanations for the noisy and often non-reproducible results that arise when trying to date the transition from the Middle to the Upper Paleolithic.

Injury perceptions of bombing survivors--interviews from the Oklahoma City bombing.

PubMed

Glenshaw, Mary T; Vernick, Jon S; Frattaroli, Shannon; Brown, Sheryll; Mallonee, Sue

2008-01-01

Bombings, including the 1995 Oklahoma City bombing, remain an important public health threat. However, there has been little investigation into the impressions of injury risk or protective factors of bombing survivors. This study analyzes Oklahoma City bombing survivors' impressions of factors that influenced their risk of injury, and validates a hazard timeline outlining phases of injury risk in a building bombing. In-depth, semi-structured interviews were conducted within a sample of Oklahoma City bombing survivors. Participants included 15 injured and uninjured survivors, who were located in three buildings surrounding the detonation site during the attack. Risk factor themes included environmental glass, debris, and entrapment. Protective factors included knowledge of egress routes, shielding behaviors to deflect debris, and survival training. Building design and health status were reported as risk and protective factors. The hazard timeline was a useful tool, but should be modified to include a lay rescue phase. The combination of a narrative approach and direct questioning is an effective method of gathering the perceptions of survivors. Investigating survivors' impressions of building bombing hazards is critical to capture injury exposures, behavior patterns, and decision-making processes during actual events, and to identify interventions that will be supported by survivors.

Reconciling radiocarbon and ice core timescales over the Holocene - Cosmogenic radionuclides as synchronization tools

NASA Astrophysics Data System (ADS)

Muscheler, R.; Adolphi, F.; Mekhaldi, F.

2015-12-01

The atmospheric production rates of cosmogenic radionuclides, such as 14C and 10Be, vary globally due to external processes, namely the solar and geomagnetic modulation of the galactic cosmic ray flux as well as solar proton events. This signature is recorded in various archives such as ice cores (10Be) and tree-rings (14C). Hence, cosmogenic radionuclides offer a means to continuously assess timescale differences between two of the most widely used timescales in paleoclimatology - the radiocarbon and the ice core timescales. Short lived solar proton events additionally provide distinct marker horizons that allow synchronization of discrete horizons at annual precision. We will present a cosmogenic radionuclide based synchronization of the Greenland ice core timescale (GICC05, Svensson et al., 2008) and the radiocarbon timescale (IntCal13, Reimer et al., 2013) over the Holocene. This synchronization allows radiocarbon dated and ice core paleoclimate records to be compared on a common timescale at down to sub-decadal precision. We will compare these results to independent discrete isochrones obtained from tephrochronology and solar proton events. In addition, we will discuss implications for the accuracy and uncertainty estimates of GICC05 over the Holocene. Reimer, P. J., Bard, E., Bayliss, A., Beck, J. W., Blackwell, P. G., Bronk Ramsey, C., Buck, C. E., Cheng, H., Edwards, R. L., Friedrich, M., Grootes, P. M., Guilderson, T. P., Haflidason, H., Hajdas, I., Hatté, C., Heaton, T. J., Hoffmann, D. L., Hogg, A. G., Hughen, K. A., Kaiser, K. F., Kromer, B., Manning, S. W., Niu, M., Reimer, R. W., Richards, D. A., Scott, E. M., Southon, J. R., Staff, R. A., Turney, C. S. M., and van der Plicht, J.: IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0-50,000 Years cal BP, Radiocarbon, 55, 1869-1887, 10.2458/azu_js_rc.55.16947, 2013. Svensson, A., Andersen, K. K., Bigler, M., Clausen, H. B., Dahl-Jensen, D., Davies, S. M., Johnsen, S. J., Muscheler, R., Parrenin

The Late Glacial Chronology from Lake Suigestu: A new approach to varve interpolation using frequency distributions of annual sub-layers

NASA Astrophysics Data System (ADS)

Schlolaut, Gordon; Marshall, Michael; Brauer, Achim; Nakagawa, Takeshi; Lamb, Henry; Staff, Richard; Bronk Ramsey, Christopher; Brock, Fiona; Bryant, Charlotte; 2006 Project Members, Suigetsu

2010-05-01

The 1993 sediment core from Lake Suigetsu is one of the most comprehensive terrestrial radiocarbon records. It is extremely rich in leaf fossils, providing a unique, truly atmospheric record of radiocarbon for the last 10-50 kyr BP (Kitagawa & van der Plicht, 2000). Since the Lake Suigetsu sediment is annually laminated (varved) for much of its depth it is suitable for extending the terrestrial radiocarbon calibration model up to 50 kyr BP. However, the data presented by Kitagawa & van der Plicht (2000) significantly diverged from alternative, marine-based calibration datasets, due to gaps in the sediment profile and varve counting uncertainties (Staff et al., 2009). In 2006 four new parallel cores were recovered from Lake Suigetsu and combined to construct a new complete and continuous master profile (SG06). Along with a new program of AMS radiocarbon measurement, varve counting is being carried out using two different techniques: i) thin section microscopy and ii) high-resolution X-ray fluorescence and X-radiography. In addition, a novel interpolation approach has been developed. First results are presented for the Late Glacial (10,200 - 15,000 kyr BP). The U-Oki Tephra at the top of this interval is used as tie point for the floating varve count chronology. Initially, the two counting methods are carried out independently. The results are then compared in detail to identify the differences down to the sub-mm scale. This new approach substantially reduces internal error and results in a greater degree of accuracy than previously possible. Due to poor varve preservation in some sediment intervals, the counts of these sections have to be interpolated. Commonly, interpolation is carried out manually using sedimentation rate estimates from neighbouring sections. The new approach presented here is based on an automated analysis of frequency distributions of annual sub-layers from the compromised section itself, allowing an estimate of the sedimentation rate unbiased

Grass material as process standard for compound-specific radiocarbon analysis

NASA Astrophysics Data System (ADS)

Cisneros-Dozal, Malu; Xu, Xiaomei; Bryant, Charlotte; Pearson, Emma; Dungait, Jennifer

2015-04-01

Compound-specific radiocarbon analysis (CSRA) is a powerful tool to study the carbon cycle and/or as a dating technique in paleoclimate reconstructions. The radiocarbon value of individual compounds can provide insight into turnover times, organic matter sources and in specific cases can be used to establish chronologies when traditional dating materials (e.g. macrofossils, pollen, charcoal) are not available. The isolation of compounds (or group of compounds) from parent material (e.g. soil, plant) for radiocarbon analysis can, however, introduce carbon contamination through chemical separation steps and preparative capillary gas chromatography (PCGC). In addition, the compounds of interest are often in low abundance which amplifies the contamination effect. The extraneous carbon can be of modern 14C age and/or 14C -free and its amount and 14C value must be determined for a given system/isolation procedure in order to report accurate 14C values. This can be achieved by using adequate standard materials but, by contrast with traditional radiocarbon dating, there are not established reference standards for CSRA work, in part because the type of standard material depends on the compounds of interest and the isolation procedure. Here we evaluate the use of n-alkanes extracted from single-year growth grass as modern process standard material for CSRA using PCGC isolation. The grass material has a known 14C value of 1.224 ± 0.006 fraction modern (FM) and the individual n-alkanes are expected to have a similar 14C value. In order to correct for the addition of extraneous carbon during PCGC isolation of the n-alkanes, we used commercially available compounds of modern 14C content and 14C -free (adipic acid, FM= 0.0015 ± 0.0001 and docosane, FM=1.059 ± 0.003) to evaluate our PCGC procedure. The corrected 14C values of the isolated n-alkanes extracted from the modern grass are within one sigma of the grass bulk 14C value for n-C29 and within two sigma for n-C23-C27, C31

Multi-method chronological investigation of a Middle Paleolithic stratigraphic context in Eastern Transylvania, Romania

NASA Astrophysics Data System (ADS)

Veres, Daniel; Cosac, Marian; Muratoreanu, George; Niţǎ, Loredana; Schmidt, Christoph; Hambach, Ulrich; Hubay, Katalin; Alexandru, Radu; Cuculici, Roxana; Lucian Buzea, Dan; Dumitraşcu, Valentin

2016-04-01

The Middle to Upper Paleolithic transition is one of the crucial periods of change in the prehistory of Europe due to the full emergence, continent-wide, of modern human technologies, detrimental of Neanderthal survival. Knowledge about the transition is vast, however, the evidence for cultural and technological developments in the Carpathian - Lower Danube area is still rather sparse. Here we discuss latest results arising from an archaeological-chronological investigation of a Middle Paleolithic context within the Varghis karst, eastern Transylvania, Romania. Combining our results with these of previous excavations, we can distinguish several stages of habitation in the area comprising a rock shelter connected to a newly discovered filled-in cave entrance. Reanalysis of the deeper stratigraphy previously unexcavated shows that at least two main habitation levels have been preserved. In both levels, the bone assemblages (Bos/Bison, Capra, Canis lupus, Ursus spaeleus) directly associated with lithics point to human-accumulation of material. In order to augment the typological cultural considerations, we applied direct radiocarbon dating on bones from within the occupation layers and on scattered charcoal, for the latter following a two-step combustion protocol (1). Radiocarbon dating on bones suggests the lowermost occupation layer is >43.4 radiocarbon kyr BP old, whereas the preliminary infrared stimulated luminescence (IRSL) ages on the lowermost productive layer and above it indicate surprisingly old ages of ca. 120 kyr and respectively, ca. 70 kyr. Multiple-protocol dating of charcoal found within the two habitation layers produced ages >38 radiocarbon kyr BP, suggesting that the lowermost habitation layer unequivocally pertains to the Middle Paleolithic industries. For the upper productive layer, radiocarbon dating of charcoal found 20 cm above it produced a surprisingly young age of 17.4 radiocarbon kyr BP. However, as the carbon content of this sample was

Closed tubes preparation of graphite for high-precision AMS radiocarbon analysis

NASA Astrophysics Data System (ADS)

Hajdas, I.; Michczynska, D.; Bonani, G.; Maurer, M.; Wacker, L.

2009-04-01

Radiocarbon dating is an established tool applied in Geochronology. Technical developments of Accelerator Mass Spectrometry AMS, which allow measurements of samples containing less than 1 mg of carbon, opened opportunities for new applications. Moreover, high resolution records of the past changes require high-resolution chronologies i.e. sampling for 14C dating. In result, the field of applications is rapidly expanding and number of radiocarbon analysis is growing rapidly. Nowadays dedicated 14C AMS machines have great capacity for analysis but in order to keep up with the demand for analysis and provide the results as fast as possible a very efficient way of sample preparation is required. Sample preparation for 14C AMS analysis consists of two steps: separation of relevant carbon from the sample material (removing contamination) and preparation of graphite for AMS analysis. The last step usually involves reaction of CO2 with H2, in the presence of metal catalyst (Fe or Co) of specific mesh size heated to 550-625°C, as originally suggested by Vogel et al. (1984). Various graphitization systems have been built in order to fulfil the requirement of sample quality needed for high-precision radiocarbon data. In the early 90ties another method has been proposed (Vogel 1992) and applied by few laboratories mainly for environmental or biomedical samples. This method uses TiH2 as a source of H2 and can be easily and flexibly applied to produce graphite. Sample of CO2 is frozen in to the tube containing pre-conditioned Zn/TiH2 and Fe catalyst. Torch sealed tubes are then placed in the stepwise heated oven at 500/550°C and left to react for several hours. The greatest problem is the lack of control of the reaction completeness and considerable fractionation. However, recently reported results (Xu et al. 2007) suggest that high precision dating using graphite produced in closed tubes might be possible. We will present results of radiocarbon dating of the set of standards

Single amino acid radiocarbon dating of Upper Paleolithic modern humans

PubMed Central

Marom, Anat; McCullagh, James S. O.; Higham, Thomas F. G.; Sinitsyn, Andrey A.; Hedges, Robert E. M.

2012-01-01

Archaeological bones are usually dated by radiocarbon measurement of extracted collagen. However, low collagen content, contamination from the burial environment, or museum conservation work, such as addition of glues, preservatives, and fumigants to “protect” archaeological materials, have previously led to inaccurate dates. These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. Here we describe a method to date hydroxyproline found in collagen (∼10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. These dates contribute considerably to our understanding of the emergence of the Mid-Upper Paleolithic and the complex suite of burial behaviors that begin to appear during this period. PMID:22517758

Single amino acid radiocarbon dating of Upper Paleolithic modern humans.

PubMed

Marom, Anat; McCullagh, James S O; Higham, Thomas F G; Sinitsyn, Andrey A; Hedges, Robert E M

2012-05-01

Archaeological bones are usually dated by radiocarbon measurement of extracted collagen. However, low collagen content, contamination from the burial environment, or museum conservation work, such as addition of glues, preservatives, and fumigants to "protect" archaeological materials, have previously led to inaccurate dates. These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. Here we describe a method to date hydroxyproline found in collagen (~10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. These dates contribute considerably to our understanding of the emergence of the Mid-Upper Paleolithic and the complex suite of burial behaviors that begin to appear during this period.

Time Matters: Increasing the Efficiency of Antarctic Marine Geology and Paleoceanography Expeditions by Providing Improved Sediment Chronology

NASA Astrophysics Data System (ADS)

Rosenheim, B. E.; Domack, E. W.; Shevenell, A.; Subt, C.

2015-12-01

To maximize the areal extent of Antarctic sedimentary records of past deglaciation, it is necessary to ensure more sediment cores can be adequately dated. Antarctic margin sediment is challenging to date due to the lack of preserved calcium carbonate, but the records contained in these sediments readily recount the history of deglaciation. Recent and continued development of new chronological methods for Antarctic margin sediments have allowed better use of the efforts of marine geological coring expeditions to the region. The development of Ramped PyrOx radiocarbon dating has allowed us to 1. improve dates in deglacial sediments where no carbonate is preserved, 2. date glacial sediments lying below the tills marking the last glaciation, and 3. compile core chronologies into a regional framework of ice shelf collapse that has eluded many marine geology campaigns over the last few decades. These advances in a fundamental aspect of geological sciences will put the U.S. and international community on a better foothold to interpret the past as it relates to our warming future. We will present these advances in chronology as well as the science that is enabled by them, while arguing that the future of Antarctic marine science also depends on investments in shore-based technologies that come at a relatively low cost.

Bombs, flyin' high. In-flight dynamics of volcanic bombs from Strombolian to Vulcanian eruptions.

NASA Astrophysics Data System (ADS)

Taddeucci, Jacopo; Alatorre, Miguel; Cruz Vázquez, Omar; Del Bello, Elisabetta; Ricci, Tullio; Scarlato, Piergiorgio; Palladino, Danilo

2016-04-01

Bomb-sized (larger than 64 mm) pyroclasts are a common product of explosive eruptions and a considerable source of hazard, both from directly impacting on people and properties and from wildfires associated with their landing in vegetated areas. The dispersal of bombs is mostly modeled as purely ballistic trajectories controlled by gravity and drag forces associated with still air, and only recently other effects, such as the influence of eruption dynamics, the gas expansion, and in-flight collisions, are starting to be quantified both numerically and observationally. By using high-speed imaging of explosive volcanic eruptions here we attempt to calculate the drag coefficient of free-flying volcanic bombs during an eruption and at the same time we document a wide range of in-flight processes affecting bomb trajectories and introducing deviations from purely ballistic emplacement. High-speed (500 frames per second) videos of explosions at Stromboli and Etna (Italy), Fuego (Gatemala), Sakurajima (Japan), Yasur (Vanuatu), and Batu Tara (Indonesia) volcanoes provide a large assortment of free-flying bombs spanning Strombolian to Vulcanian source eruptions, basaltic to andesitic composition, centimeters to meters in size, and 10 to 300 m/s in fly velocity. By tracking the bombs during their flying trajectories we were able to: 1) measure their size, shape, and vertical component of velocity and related changes over time; and 2) measure the different interactions with the atmosphere and with other bombs. Quantitatively, these data allow us to provide the first direct measurement of the aerodynamic behavior and drag coefficient of volcanic bombs while settling, also including the effect of bomb rotation and changes in bomb shape and frontal section. We also show how our observations have the potential to parameterize a number of previously hypothesized and /or described but yet unquantified processes, including in-flight rotation, deformation, fragmentation, agglutination

Critical review of a new volcanic eruption chronology

NASA Astrophysics Data System (ADS)

Neuhäuser, Dagmar L.; Neuhäuser, Ralph

2016-04-01

Sigl. et al. (2015, Nature) present historical evidence for 32 volcanic eruptions to evaluate their new polar ice core 10-Be chronology - 24 are dated within three years of sulfur layers in polar ice. Most of them can be interpreted as weather phenomena (Babylonia: disk of sun like moon, reported for only one day, e.g. extinction due to clouds), Chinese sunspot reports (pellet, black vapor, etc.), solar eclipses, normal ice-halos and coronae (ring, bow, etc.), one aurora (redness), red suns due to mist drops in wet fog or fire-smoke, etc. Volcanic dust may facilitate detections of sunspots and formation of Bishop's ring, but tend to inhibit ice-halos, which are otherwise often reported in chronicles. We are left with three reports possibly indicating volcanic eruptions, namely fulfilling genuine criteria for atmospheric disturbances due to volcanic dust, e.g. bluish or faint sun, orange sky, or fainting of stars for months (BCE 208, 44-42, and 32). Among the volcanic eruptions used to fix the chronology (CE 536, 626, 939, 1257), the reports cited for the 930s deal only with 1-2 days, at least one reports an eclipse. In the new chronology, there is a sulfur detection eight years after the Vesuvius eruption, but none in CE 79. It may appear surprising that, from BCE 500 to 1, all five northern sulfur peaks labeled in figure 2 in Sigl et al. are systematically later by 2-4 years than the (corresponding?) southern peaks, while all five southern peaks from CE 100 to 600 labeled in figure 2 are systematically later by 1-4 years than the (corresponding?) northern peaks. Furthermore, in most of their six strongest volcanic eruptions, temperatures decreased years before their sulfur dating - correlated with weak solar activity as seen in radiocarbon, so that volcanic climate forcing appears dubious here. Also, their 10-Be peaks at CE 775 and 994 are neither significant nor certain in dating.

Rethinking suicide bombing.

PubMed

Aggarwal, Neil

2009-01-01

Current issues in the emerging psychiatric literature on suicide bombing tend to center around the pathologies of suicide bombers and the role of psychiatry as an adequate tool for analysis. Attention to broader social science research may allow mental health professionals to develop more accurate models of behavior to explain and possibly prevent future attacks. The psychiatric literature on suicide bombing was reviewed and compared to similar anthropological literature. A probe into the methodologies of researching suicide bombing, definitions of "war" and "terrorism", and beliefs on life, death, homicide, and suicide demonstrate that most of the psychiatric literature reflects a particular perspective which aspires towards a certain universalism. Anthropological approaches can disclose standpoints taken for granted since any interventions with respect to suicide bombing must eventually account for values which are ultimately culturally determined.

Environmental tritium and radiocarbon studies in the Vedavati River basin, Karnataka and Andhra Pradesh, India

NASA Astrophysics Data System (ADS)

Sukhija, B. S.; Achutha Rao, A.

1983-01-01

Environmental tritium and radiocarbon studies were undertaken in the Vedavati river basin situated partly in Karnataka and partly in Andhra Pradesh, India, aimed at the determination of the general recharge condition of the water-bearing zones in the gneissic complex, granites and the Dharwar Group of metamorphic rocks, where groundwater occurs under semi-unconfined to semi-confined conditions and at places under the water-table condition. The groundwater movement is controlled by fractures, fissures, a weathered zone and surficial mantle. An attempt was also made to find out whether substantial recharge occurs along fractured lineaments; whether the water-bearing zones can be considered as interconnected or isolated, and whether the recharge and discharge areas identified by geohydrological considerations can be confirmed. Environmental tritium and radiocarbon contents, measured in ˜ 45 groundwater samples, show that a large number of samples are very young, containing water from post-thermonuclear-era rain, thus indicating an age less than 25 yr. In some other samples, despite radiocarbon ages found to be older, some component of recent precipitation is found to be present as indicated by bomb tritium. Groundwater dating in the area shows an excellent correlation between hydro-isochrons of minimum age with the recharge contour of maximum magnitude. This study has clearly resulted in the demarcation of the recharge areas. However, the discharge areas as such cannot be clearly delineated because of lack of a pattern indicating increase of ages in any particular direction. This, however, also reflects somewhat discontinuous groundwater bodies, which may also be expected from the general structure and hydrogeology of the region. Along a major lineament the groundwater is found to be very young thus confirming that substantial recharge occurs along lineaments.

Radiocarbon dating of the Late Cycladic building and destruction phases at Akrotiri, Thera: New evidence

NASA Astrophysics Data System (ADS)

Maniatis, Yannis

2012-01-01

Akrotiri was a flourishing prehistoric settlement on the Cycladic island of Santorini (Thera) until its life was ended by a huge volcanic eruption in the LCI period. There is much debate as to when this final destruction occurred. Based on the Egyptian historical dating this happened around 1540-1530 BC, while, based on radiocarbon and other scientific data, around 1640-1600 BC. This work is an attempt to date with radiocarbon the whole settlement's life starting from the earlier phases of occupation but focusing in the sequence of the latest events. The samples, coming from the deep shafts dug in the site for the pillars of the new shelter, are pieces of wood and charcoal from house architectural elements and other constructions, including the final earthquake victims temporary camps. Therefore, the dates obtained represent the beginning of the different cultural phases plus the latest events. The results provide novel absolute dates for the commencement of the LMC and LCI Phases at Akrotiri, giving mean ranges around 1820-1790 BC and 1775-1722 BC, respectively, while the final destruction is dated around 1622-1548 BC. These results show that the LCI phase started about 100 years earlier than estimated with the Egyptian Historical chronology while the final destruction around 60 years or less earlier.

Cluster bomb ocular injuries.

PubMed

Mansour, Ahmad M; Hamade, Haya; Ghaddar, Ayman; Mokadem, Ahmad Samih; El Hajj Ali, Mohamad; Awwad, Shady

2012-01-01

To present the visual outcomes and ocular sequelae of victims of cluster bombs. This retrospective, multicenter case series of ocular injury due to cluster bombs was conducted for 3 years after the war in South Lebanon (July 2006). Data were gathered from the reports to the Information Management System for Mine Action. There were 308 victims of clusters bombs; 36 individuals were killed, of which 2 received ocular lacerations and; 272 individuals were injured with 18 receiving ocular injury. These 18 surviving individuals were assessed by the authors. Ocular injury occurred in 6.5% (20/308) of cluster bomb victims. Trauma to multiple organs occurred in 12 of 18 cases (67%) with ocular injury. Ocular findings included corneal or scleral lacerations (16 eyes), corneal foreign bodies (9 eyes), corneal decompensation (2 eyes), ruptured cataract (6 eyes), and intravitreal foreign bodies (10 eyes). The corneas of one patient had extreme attenuation of the endothelium. Ocular injury occurred in 6.5% of cluster bomb victims and 67% of the patients with ocular injury sustained trauma to multiple organs. Visual morbidity in civilians is an additional reason for a global ban on the use of cluster bombs.

Chronologic evidence for multiple periods of loess deposition during the Late Pleistocene in the Missouri and Mississippi River Valley, United States: Implications for the activity of the Laurentide ice sheet

USGS Publications Warehouse

Forman, S.L.; Bettis, E. Arthur; Kemmis, T.J.; Miller, B.B.

1992-01-01

The loess stratigraphy of the mid-continental U.S. is an important proxy record for the activity of the Laurentide Ice Sheet in North America. One of the most outstanding problems is deciphering the age of loess deposits in this area during the late Pleistocene. Radiocarbon dating of snails and thermoluminescence dating of the fine-silt fraction (4-11 ??m) from loess at the Loveland Loess type section, Loveland, Iowa and a recent excavation at the Pleasant Grove School section. Madison County, Illinois provide new chronologic control on loess deposition in the Mississippi/Missouri River Valley chronology indicates that the Loveland Loess is Illinoian in age (135??20 ka) but is not correlative with the Teneriffe Silt which is dated to 77 ?? 8 ka. Concordant radiocarbon and thermoluminescence age estimates demonstrate that the Roxana Silt and a correlative loess in Iowa, the Pisgah Formation, is probably 40-30 ka old. These age estimates in conjunction with previous results indicate that there were four periods of loess deposition during the last 150 ka at 25-12 ka, 45-30 ka, 85-70 ka and at ca. 135 ?? 20 ka. This chronology of loess deposition supports the presence of both a late Illinoian and early Wisconsinan loess and associated soils. Thus, there may be more than one soil in the loess stratigraphy of the mid-continental U.S. with morphologies similar to the Sangamon Soil. The last three periods of loess deposition may be correlative with periods of elevated dust concentrations recorded in the Dye 3 ice core from southern Greenland. This is particularly significant because both areas possibly had the same source for eolian particles. Reconstructions of atmospheric circulation for glacial periods show a southerly deflected jet stream that could have transported dust from the mid-continental USA to southern Greenland. Lastly, the inferred record of loess deposition is parallel to a chronology for deglaciation of the Laurentide Ice Sheet deciphered from chronologic

Carbon cycling in fine roots of several mature forests: results using either locally-derived or bomb-derived radiocarbon enrichment

NASA Astrophysics Data System (ADS)

Gaudinski, J. B.; Riley, W. J.; Torn, M. S.; Dawson, T. E.; Trumbore, S. E.; Joslin, J. D.; Majdi, H.; Hanson, P. J.; Swanston, C.

2008-12-01

This work seeks to improve our ability to quantify C cycling rates in fine roots of trees in mature deciduous and coniferous forests. We use two different types of atmospheric 14CO2 enrichment to trace the time elapsed since C in plant tissues was fixed from the atmosphere by photosynthesis. The first uses a local enrichment of 14CO2 which occurred in early summer 1999, at the Oak Ridge Reservation, Tennessee. The second, employed at three different sites, uses the global enrichment in background atmospheric 14CO2 caused by thermonuclear weapons testing (bomb-14C). In both cases we employ a new model (Radix1.0) to track C and 14C fluxes through fine root populations. Radix simulates two live-root populations (the longer-lived one having structural and non-structural C components), two dead-root pools, non-normally distributed root mortality turnover times, a stored C pool, seasonal growth and respiration patterns, a best-fit to measurements approach to estimate model parameters, and Monte Carlo uncertainty analysis. Our results show that: (1) New fine-root growth contains a lot of stored C (~55%) but it is young in age (0.7 y). (2) The effect of stored reserves on estimated ages of fine roots is unlikely to be large in most natural abundance isotope studies. However, models should take stored reserves into account, particularly for pulse labeling studies and fast-cycling roots (< 1 y). (3) Radiocarbon values show a stronger correlation with position on the root branch system than they do with diameter or depth in the soil profile. (4) Live fine root dynamics are well described by a short-lived and a long-lived population, with mean turnover times <1 y and ~12 y, respectively. (5) Dead root decomposition is best modeled with (at least) two pools, with moderate (~2 y) and slow (~10 y) decomposition turnover times. (6) Root respiration has a large effect on fine root biomass and isotopic composition, and should be included in ecosystem C and isotope models. (7) It is

Suicide Bombing Attacks

PubMed Central

Almogy, Gidon; Belzberg, Howard; Mintz, Yoaz; Pikarsky, Alon K.; Zamir, Gideon; Rivkind, Avraham I.

2004-01-01

Objective: To review the experience of a large-volume trauma center in managing and treating casualties of suicide bombing attacks. Summary Background Data: The threat of suicide bombing attacks has escalated worldwide. The ability of the suicide bomber to deliver a relatively large explosive load accompanied by heavy shrapnel to the proximity of his or her victims has caused devastating effects. Methods: The authors reviewed and analyzed the experience obtained in treating victims of suicide bombings at the level I trauma center of the Hadassah University Hospital in Jerusalem, Israel from 2000 to 2003. Results: Evacuation is usually rapid due to the urban setting of these attacks. Numerous casualties are brought into the emergency department over a short period. The setting in which the device is detonated has implications on the type of injuries sustained by survivors. The injuries sustained by victims of suicide bombing attacks in semi-confined spaces are characterized by the degree and extent of widespread tissue damage and include multiple penetrating wounds of varying severity and location, blast injury, and burns. Conclusions: The approach to victims of suicide bombings is based on the guidelines for trauma management. Attention is given to the moderately injured, as these patients may harbor immediate life-threatening injuries. The concept of damage control can be modified to include rapid packing of multiple soft-tissue entry sites. Optimal utilization of manpower and resources is achieved by recruiting all available personnel, adopting a predetermined plan, and a centrally coordinated approach. Suicide bombing attacks seriously challenge the most experienced medical facilities. PMID:15075644

Radiocarbon dating the appearance of modern humans and timing of cultural innovations in Europe: new results and new challenges.

PubMed

Conard, Nicholas J; Bolus, Michael

2003-03-01

New radiocarbon dates from the sites of Bockstein-Törle, Geissenklösterle, Hohle Fels, Hohlenstein-Stadel, Sirgenstein, and Vogelherd in the Swabian Jura of southwestern Germany indicate that the Aurignacian of the region spans the period from ca. 40-30ka BP. If the situation at Vogelherd, in which skeletal remains from modern humans underlie an entire Aurignacian sequence, is viewed as representative for the region, the dates from the Swabian Jura support the hypothesis that populations of modern humans entered the region by way of the "Danube Corridor." The lithic technology from the lower Aurignacian of Geissenklösterle III is fully developed, and classic Aurignacian forms are well represented. During the course of the Aurignacian, numerous assemblages rich in art works, jewelry, and musical instruments are documented. By no later than 29ka BP the Gravettian was well established in the region. These dates are consistent with the "Kulturpumpe" hypothesis that important cultural innovations of the Aurignacian and Gravettian in Swabia predate similar developments in other regions of Europe. The radiocarbon dates from Geissenklösterle corroborate observations from other non-archaeological data sets indicating large global fluctuations in the atmospheric concentrations of radiocarbon between 30 and 50ka calendar years ago. These fluctuations lead to complications in building reliable chronologies during this period and cause the "Middle Paleolithic Dating Anomaly" and the "Coexistence Effect," which tend to exaggerate the temporal overlap between Neanderthals and modern humans.

Chronology and ecology of late Pleistocene megafauna in the northern Willamette Valley, Oregon

USGS Publications Warehouse

Gilmour, Daniel M.; Butler, Virginia L.; O'Connor, James E.; Davis, Edward Byrd; Culleton, Brendan J.; Kennett, Douglas J.; Hodgins, Gregory W. L.

2015-01-01

Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic and isotopic analyses in conjunction with updated evaluations of stratigraphic context provide substantial new information on the species present, timing of losses, and paleoenvironmental conditions. Using subfossil material from the northern valley, we use AMS radiocarbon dating, stable isotope (δ13C and δ15N) analyses, and taxonomic dietary specialization and habitat preferences to reconstruct environments and to develop a local chronology of events that we then compare with continental and regional archaeological and paleoenvironmental data. Analysis of twelve bone specimens demonstrates the presence of bison, mammoth, horse, sloth, and mastodon from ~ 15,000–13,000 cal yr BP. The latest ages coincide with changing regional climate corresponding to the onset of the Younger Dryas. It is suggested that cooling conditions led to increased forest cover, and, along with river aggradation, reduced the area of preferred habitat for the larger bodied herbivores, which contributed to the demise of local megafauna. Archaeological evidence for megafauna–human interactions in the Pacific Northwest is scarce, limiting our ability to address the human role in causing extinction.

Radiocarbon dating of magnetic and non magnetic soil fractions as a method to estimate the heterotrophic component of soil respiration in a primary forest of Ghana.

NASA Astrophysics Data System (ADS)

Chiti, T.; Certini, G.; Marzaioli, F.; Valentini, R.

2012-04-01

We estimated the heterotrophic component (Rh) of soil respiration in a primary forest of Ghana by radiocarbon dating, a method we already successfully applied in temperate and Mediterranean forests. In this case, given the advanced stage of alteration of tropical soils, which are thus rich in oxides, we implemented the method on soil fractions obtained by High Gradient Magnetic Separation (HGMS), hence based on different degrees of magnetic susceptibility. In particular, we separated an organic pool associated with magnetic minerals (e.g iron oxides) from an organic pool engaged with non-magnetic minerals. This non destructive method of fractionation, often applied to the finest fraction of soil (clay), is here attempted on the bulk fine earth (< 2 mm). We sampled the soil at 0-5, 5-15, 15-10, and 30-50 cm depth intervals, since a previous study in the same site suggested that only the first 50 cm of soil was enriched in bomb carbon (C younger than 1950). The samples of each layer were sieved at 2 mm and further at 0.5 mm ,so as to have two size fractions: 2 to 0.5 mm and <0.5 mm, and both of them were separated into a magnetic and non magnetic fraction. All the specimens were then investigated in terms of mineralogical assemblage (by X-Ray diffrattometry), chemical structure of the organic component (13C NMR spectroscopy), and 14C concentration (AMS) for inferring the mean residence time (MRT) of the organic component in the soil. Radiocarbon concentration was always higher in the finest SOC fractions (<0.5 mm), with the magnetic fraction always showing an higher 14C concentration than the non magnetic one. The magnetic and non magnetic materials of the coarser fraction (0.5-2 mm) showed quite similar 14C concentrations in all of the soil layers investigated. The composition of the organic matter is different in the different fractions and partly explains the differences in MRT, although a major role in preserving the organics from decomposition is probably played

Integrated multi-site U-Th chronology of the last glacial Lake Lisan

NASA Astrophysics Data System (ADS)

Torfstein, Adi; Goldstein, Steven L.; Kagan, Elisa J.; Stein, Mordechai

2013-03-01

We present a new integrated multi-site chronology for Lake Lisan, which occupied the Dead Sea basin and Jordan Valley during the last glacial period (70-14 kka, Marine Isotope Stages 4, 3, 2). The Dead Sea basin lacustrine deposits are unique among closed basin sediments in that they formed in a deep, hypersaline water body that precipitated primary aragonite which is amenable to radiometric dating by U-series, providing a solid basis for studies of the relationship of Middle East climate to other changes in the high latitudes or the tropics. The application of U-Th dating for lacustrine carbonates requires corrections for detrital U and Th and hydrogenous ("initial") 230Th. Here we followed an iterative approach, in which we evaluate the composition of the detrital contamination independently for every set of coeval samples to determine the corrected ages. These were further filtered and combined with lithological-limnological considerations, which were used to construct age-height models for all studied stratigraphic sections. Finally, the ages of stratigraphic tie-points were used to integrate the individual age-height models into a unified chronology. The resulting chronological framework indicates that the ages of several primary gypsum units associated with catastrophic lake level drops correspond with the timing of Heinrich events in the North Atlantic. Thus, a final iterative step involves refining the ages of "Lisan-gypsum events" based on the ages of Heinrich events 6, 5, 5a, 4, and 1. This approach yields an unprecedented basin-wide, unified, event-anchored chronology for the Lisan Formation, with typical age uncertainties ca. 1000-2000 years (95% confidence limit) across the entire last glacial, well below those typically related to individual U-Th and radiocarbon dating of "dirty" carbonates from similar time intervals. The results can be further extrapolated to new sites and serve as a geochronometric reference for the reconstruction of the

Cluster Bomb Ocular Injuries

PubMed Central

Mansour, Ahmad M.; Hamade, Haya; Ghaddar, Ayman; Mokadem, Ahmad Samih; El Hajj Ali, Mohamad; Awwad, Shady

2012-01-01

Purpose: To present the visual outcomes and ocular sequelae of victims of cluster bombs. Materials and Methods: This retrospective, multicenter case series of ocular injury due to cluster bombs was conducted for 3 years after the war in South Lebanon (July 2006). Data were gathered from the reports to the Information Management System for Mine Action. Results: There were 308 victims of clusters bombs; 36 individuals were killed, of which 2 received ocular lacerations and; 272 individuals were injured with 18 receiving ocular injury. These 18 surviving individuals were assessed by the authors. Ocular injury occurred in 6.5% (20/308) of cluster bomb victims. Trauma to multiple organs occurred in 12 of 18 cases (67%) with ocular injury. Ocular findings included corneal or scleral lacerations (16 eyes), corneal foreign bodies (9 eyes), corneal decompensation (2 eyes), ruptured cataract (6 eyes), and intravitreal foreign bodies (10 eyes). The corneas of one patient had extreme attenuation of the endothelium. Conclusions: Ocular injury occurred in 6.5% of cluster bomb victims and 67% of the patients with ocular injury sustained trauma to multiple organs. Visual morbidity in civilians is an additional reason for a global ban on the use of cluster bombs. PMID:22346132

Mortar radiocarbon dating: preliminary accuracy evaluation of a novel methodology.

PubMed

Marzaioli, Fabio; Lubritto, Carmine; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Terrasi, Filippo

2011-03-15

Mortars represent a class of building and art materials that are widespread at archeological sites from the Neolithic period on. After about 50 years of experimentation, the possibility to evaluate their absolute chronology by means of radiocarbon ((14)C) remains still uncertain. With the use of a simplified mortar production process in the laboratory environment, this study shows the overall feasibility of a novel physical pretreatment for the isolation of the atmospheric (14)CO(2) (i.e., binder) signal absorbed by the mortars during their setting. This methodology is based on the assumption that an ultrasonic attack in liquid phase isolates a suspension of binder carbonates from bulk mortars. Isotopic ((13)C and (14)C), % C, X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses were performed to characterize the proposed methodology. The applied protocol allows suppression of the fossil carbon (C) contamination originating from the incomplete burning of the limestone during the quick lime production, providing unbiased dating for "laboratory" mortars produced operating at historically adopted burning temperatures.

Si-Traceable Scale for Measurements of Radiocarbon Concentration

NASA Astrophysics Data System (ADS)

Hodges, Joseph T.; Fleisher, Adam J.; Liu, Qingnan; Long, David A.

2017-06-01

Radiocarbon (^{14}C) dating of organic materials is based on measuring the ^{14}C/^{12}C atomic fraction relative to the nascent value that existed when the material was formed by photosynthetic conversion of carbon dioxide present in the atmosphere. This field of measurement has numerous applications including source apportionment of anthropogenic and biogenic fuels and combustion emissions, carbon cycle dynamics, archaeology, and forensics. Accelerator mass spectrometry (AMS) is the most widely used method for radiocarbon detection because it can measure extremely small amounts of radiocarbon (background of nominally 1.2 parts-per-trillion) with high relative precision (0.4 %). AMS measurements of radiocarbon are typically calibrated by reference to standard oxalic-acid (C_2H_2O_4) samples of known radiocativity that are derived from plant matter. Specifically, the internationally accepted absolute dating reference for so-called "modern-equivalent" radiocarbon is 95 % of the specific radioactivity in AD 1950 of the National Bureau of Standards (NBS) oxalic acid standard reference material and normalized to δ^{13}C_{VPDB} = 19 per mil. With this definition, a "modern-equivalent" corresponds to 1.176(70) parts-per-trillion of ^{14}C relative to total carbon content. As an alternative radiocarbon scale, we propose an SI-traceable method to determine ^{14}C absolute concentration which is based on linear Beer-Lambert-law absorption measurements of selected ^{14}C^{16}O_2 ν_3-band line areas. This approach is attractive because line intensities of chosen radiocarbon dioxide transitions can be determined by ab initio calculations with relative uncertainties below 0.5 %. This assumption is justified by the excellent agreement between theoretical values of line intensities and measurements for stable isotopologues of CO_2. In the case of cavity ring-down spectroscopy (CRDS) measurements of ^{14}C^{16}O_2 peak areas, we show that absolute, SI-traceable concentrations of

Radiocarbon Dating the Anthropocene

NASA Astrophysics Data System (ADS)

Chaput, M. A.; Gajewski, K. J.

2015-12-01

The Anthropocene has no agreed start date since current suggestions for its beginning range from Pre-Industrial times to the Industrial Revolution, and from the mid-twentieth century to the future. To set the boundary of the Anthropocene in geological time, we must first understand when, how and to what extent humans began altering the Earth system. One aspect of this involves reconstructing the effects of prehistoric human activity on the physical landscape. However, for global reconstructions of land use and land cover change to be more accurately interpreted in the context of human interaction with the landscape, large-scale spatio-temporal demographic changes in prehistoric populations must be known. Estimates of the relative number of prehistoric humans in different regions of the world and at different moments in time are needed. To this end, we analyze a dataset of radiocarbon dates from the Canadian Archaeological Radiocarbon Database (CARD), the Palaeolithic Database of Europe and the AustArch Database of Australia, as well as published dates from South America. This is the first time such a large quantity of dates (approximately 60,000) has been mapped and studied at a global scale. Initial results from the analysis of temporal frequency distributions of calibrated radiocarbon dates, assumed to be proportional to population density, will be discussed. The utility of radiocarbon dates in studies of the Anthropocene will be evaluated and potential links between population density and changes in atmospheric greenhouse gas concentrations, climate, migration patterning and fire frequency coincidence will be considered.

Chronological reconstruction of eolianites and transversal mobile dunes of northwest coast of Ceará State - Brazil, in the last 3000 cal yrs BP

NASA Astrophysics Data System (ADS)

Castro, João Wagner Alencar; Malta, Julia Varella; Miguel, Lucas Lavo Antonio Jimo; Cabral, Caique Lima; Passemilio, Alvaro Balmant

2017-10-01

Dunefields are very common in the northern coastal zone of northeast Brazil. They have the potential to yield important information about paleoclimate, paleo-winds and regional winds and their response to sea-level fluctuations during the Holocene. We reconstructed the coastal dunes geochronological evolution of northwest Ceará State - Brazil, in the last 3000 cal yrs BP, using detailed analyses of lithostratigraphy, microfossil (foraminifera), wind regime, dune monitoring and 8 radiocarbon dates. The chronology was based on 14C dating in eolianites and monitoring transversal mobile dunes movement processes. Radiocarbon date results indicated that the dunes corresponding to eolianites revealed ages between 2760-2480 and 980-750 cal yrs BP, suggesting that the vast transversal mobile dunefields were formed after this period in similar condition to the current sea-level. We considered that the material transportation by the prevailing east winds towards the transversal dunes is estimated in the order of 11.0 m/year, thus the current aeolian system is less than 1000 yrs BP.

Time Variation of the Distance Separating Bomb and Dive Bomber Subsequent to Bomb Release

NASA Technical Reports Server (NTRS)

Mathews, Charles W.

1952-01-01

A study has been made of the variation of the distance separating bomb and aircraft with time after release as applied to dive-bombing operations, Separation distances determined from this study are presented in terms of two variables only, dive angle and maximum airplane accelerometer reading; the values of separation distance include the effects of delay in initiation of the pull-out and lag in attainment of the maximum normal acceleration.Contains analysis and calculations of the separation distances between bomb and dive bomber following bomb release, Separation distances as determined by the dive angle and the maximum airplane accelerometer reading are presented in a single chart.

Stable and radiocarbon isotopic composition of dissolved organic matter in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Walker, B. D.; Druffel, E. R. M.; Kolasinski, J.; Roberts, B. J.; Xu, X.; Rosenheim, B. E.

2017-08-01

Dissolved organic carbon (DOC) is of primary importance to marine ecosystems and the global carbon cycle. Stable carbon (δ13C) and radiocarbon (Δ14C) isotopic measurements are powerful tools for evaluating DOC sources and cycling. However, the isotopic signature of DOC in the Gulf of Mexico (GOM) remains almost completely unknown. Here we present the first DOC Δ14C and δ13C depth profiles from the GOM. Our results suggest the Mississippi River exports large amounts of DOC with an anthropogenic "bomb" Δ14C signature. Riverine DOC is removed and recycled offshore, and some marine production of DOC is observed in the river plume. Offshore profiles show that DOC has higher Δ14C than its Caribbean feed waters, indicative of a modern deep DOC source in the GOM basin. Finally, high DOC with negative δ13C and Δ14C values were observed near the Macondo Wellhead, suggesting a transformation of Deepwater Horizon hydrocarbons into a persistent population of DOC.

Bomb Cyclones Of The Western North Atlantic

NASA Astrophysics Data System (ADS)

Adams, Ryan E.

"Bomb" cyclones represent a small subset of mid-latitude cyclones characterized by rapid intensification and frequently are associated with extreme weather conditions along the eastern coast of North America. Like other extreme phenomena, bomb cyclone predictions are prone to error leading to inadequate or untimely hazard warnings. The rare nature of bomb cyclones and the uniqueness of their evolutions has made it difficult for researchers to make meaningful generalizations on bomb cyclone events. This paper describes bomb cyclone climatology for the western North Atlantic, using data from the NCEP-NCAR Reanalysis for 1948-2016, and uses a synoptic climatological analysis to relate these bombs to their associated atmospheric environments. A self-organizing map (SOM) of 300-hPa geopotential height tendency is created to partition the regional atmospheric environment. Thermodynamic fields are contrasted by each 300-hPa geopotential height tendency pattern for both bomb and non-bomb events in composite difference maps. The SOM patterns most significantly associated with western North Atlantic bomb cyclogenesis are characterized by both strongly and weakly negative height tendencies along the eastern United States. In both cases, these patterns exhibit strong meridional flow, a distinction marked by the weakening and breaking down of the polar vortex in the boreal Winter. The composite maps for each pattern show the mean differences in low-mid level ascent and near surface thermodynamics for bomb environments contrasted with non-bomb environments, resulting in diverse spatiotemporal distributions of bombs in the western North Atlantic.

Pre-aged plant waxes in tropical lake sediments and their influence on the chronology of molecular paleoclimate proxy records

NASA Astrophysics Data System (ADS)

Douglas, Peter M. J.; Pagani, Mark; Eglinton, Timothy I.; Brenner, Mark; Hodell, David A.; Curtis, Jason H.; Ma, Keith F.; Breckenridge, Andy

2014-09-01

Sedimentary records of plant-wax hydrogen (δDwax) and carbon (δ13Cwax) stable isotopes are increasingly applied to infer past climate change. Compound-specific radiocarbon analyses, however, indicate that long time lags can occur between the synthesis of plant waxes and their subsequent deposition in marginal marine sediments. The influence of these time lags on interpretations of plant-wax stable isotope records is presently unconstrained, and it is unclear whether such time lags also affect lacustrine sediments. We present compound-specific radiocarbon (14Cwax) data for n-alkanoic acid plant waxes (n-C26 to n-C32) from: (1) a sediment core from Lake Chichancanab, Yucatan Peninsula, Mexico, (2) soils in the Lake Chichancanab catchment, and (3) surface sediments from three other lakes in southeastern Mexico and northern Guatemala. 14Cwax ages in the surface sediments are consistently older than modern, and may be negatively correlated with mean annual precipitation and positively correlated with lake catchment area. 14Cwax ages in soils surrounding Lake Chichancanab increase with soil depth, consistent with deep, subsoil horizons being the primary source of lacustrine aged plant waxes, which are likely delivered to lake sediments through subsurface transport. Plant waxes in the Lake Chichancanab core are 350-1200 years older than corresponding ages of bulk sediment deposition, determined by 14C dates on terrestrial plant macrofossils in the core. A δDwax time series is in closer agreement with other regional proxy hydroclimate records when a plant-wax 14C age model is applied, as opposed to the macrofossil-based core chronology. Inverse modeling of plant-wax age distribution parameters suggests that plant waxes in the Lake Chichancanab sediment core derive predominantly from millennial-age soil carbon pools that exhibit relatively little age variance (<200 years). Our findings demonstrate that high-temporal-resolution climate records inferred from stable isotope

Are IRIS Bombs Connected to Ellerman Bombs?

NASA Astrophysics Data System (ADS)

Tian, Hui; Xu, Zhi; He, Jiansen; Madsen, Chad

2016-06-01

Recent observations by the Interface Region Imaging Spectrograph (IRIS) have revealed pockets of hot gas (˜2-8 × 104 K) potentially resulting from magnetic reconnection in the partially ionized lower solar atmosphere (IRIS bombs; IBs). Using joint observations between IRIS and the Chinese New Vacuum Solar Telescope, we have identified 10 IBs. We find that 3 are unambiguously and 3 others are possibly connected to Ellerman bombs (EBs), which show intense brightening of the extended {{{H}}}α wings without leaving an obvious signature in the {{{H}}}α core. These bombs generally reveal the following distinct properties: (1) the O IV 1401.156 Å and 1399.774 Å lines are absent or very weak; (2) the Mn I 2795.640 Å line manifests as an absorption feature superimposed on the greatly enhanced Mg II k line wing; (3) the Mg II k and h lines show intense brightening in the wings and no dramatic enhancement in the cores; (4) chromospheric absorption lines such as Ni II 1393.330 Å and 1335.203 Å are very strong; and (5) the 1700 Å images obtained with the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory reveal intense and compact brightenings. These properties support the formation of these bombs in the photosphere, demonstrating that EBs can be heated much more efficiently than previously thought. We also demonstrate that the Mg II k and h lines can be used to investigate EBs similarly to {{{H}}}α , which opens a promising new window for EB studies. The remaining four IBs obviously have no connection to EBs and they do not have the properties mentioned above, suggesting a higher formation layer, possibly in the chromosphere.

RADIOCARBON SOURCE APPORTIONMENT IN A BIOFUELS ERA

EPA Science Inventory

Biofuels (gasohol and biodiesel) introduce radiocarbon into the U.S. mobile source fuel supply where it was previously absent. Initial measurements of radiocarbon in the PM_2.5 combustion emissions from engines using gasohol indicate that this may have less effect on r...

Surface water processes in the Indonesian throughflow as documented by a high-resolution coral Δ14C record

NASA Astrophysics Data System (ADS)

Fallon, Stewart J.; Guilderson, Thomas P.

2008-09-01

To explore the seasonal to decadal variability in surface water masses that contribute to the Indonesian throughflow, we have generated a 115-year bimonthly coral-based radiocarbon time series from a coral in the Makassar Straits. In the pre-bomb (pre-1955) era from 1890 to 1954, the radiocarbon time series occasionally displays a small seasonal signal (10-15‰). After 1954 the radiocarbon record increases rapidly, in response to the increased atmospheric 14C content caused by nuclear weapons testing. From 1957 to 1986 the record displays clear seasonal variability from 15 to 60‰ and the post-bomb peak (163 per mil) occurred in 1974. The seasonal cycle of radiocarbon can be attributed to variations of surface waters passing through the South Makassar Strait. Southern Makassar is under the influence of the Northwest Monsoon, which is responsible for the high austral summer radiocarbon (North Pacific waters) and the Southeast Monsoon that flushes back a mixture of low (South Pacific and upwelling altered) radiocarbon water from the Banda Sea. The coral record also shows a significant 14C peak in 1955 due to the bomb-14C water advected into this region from nuclear weapons tests in the Marshall Islands in 1954.

Atomic Bomb Health Benefits

PubMed Central

Luckey, T. D.

2008-01-01

Media reports of deaths and devastation produced by atomic bombs convinced people around the world that all ionizing radiation is harmful. This concentrated attention on fear of miniscule doses of radiation. Soon the linear no threshold (LNT) paradigm was converted into laws. Scientifically valid information about the health benefits from low dose irradiation was ignored. Here are studies which show increased health in Japanese survivors of atomic bombs. Parameters include decreased mutation, leukemia and solid tissue cancer mortality rates, and increased average lifespan. Each study exhibits a threshold that repudiates the LNT dogma. The average threshold for acute exposures to atomic bombs is about 100 cSv. Conclusions from these studies of atomic bomb survivors are: One burst of low dose irradiation elicits a lifetime of improved health.Improved health from low dose irradiation negates the LNT paradigm.Effective triage should include radiation hormesis for survivor treatment. PMID:19088902

Atomic bomb health benefits.

PubMed

Luckey, T D

2008-01-01

Media reports of deaths and devastation produced by atomic bombs convinced people around the world that all ionizing radiation is harmful. This concentrated attention on fear of miniscule doses of radiation. Soon the linear no threshold (LNT) paradigm was converted into laws. Scientifically valid information about the health benefits from low dose irradiation was ignored. Here are studies which show increased health in Japanese survivors of atomic bombs. Parameters include decreased mutation, leukemia and solid tissue cancer mortality rates, and increased average lifespan. Each study exhibits a threshold that repudiates the LNT dogma. The average threshold for acute exposures to atomic bombs is about 100 cSv. Conclusions from these studies of atomic bomb survivors are: One burst of low dose irradiation elicits a lifetime of improved health.Improved health from low dose irradiation negates the LNT paradigm.Effective triage should include radiation hormesis for survivor treatment.

Recent advances in long-term climate and moisture reconstructions from the Baltic region: Exploring the potential for a new multi-millennial tree-ring chronology

NASA Astrophysics Data System (ADS)

Edvardsson, Johannes; Corona, Christophe; Mažeika, Jonas; Pukienė, Rutile; Stoffel, Markus

2016-01-01

This study presents the first results from an ongoing initiative to develop a multi-millennial Baltic tree-ring width (TRW) chronology consisting of 12 floating records from subfossil Scots pines (Pinus sylvestris L.) extracted from three Lithuanian peat-mining areas. The floating series have been complemented with absolutely dated TRW chronologies which were obtained from living trees growing in unmanaged and unexploited peatland areas adjacent to each of the above study sites. The subfossil material has been dated by radiocarbon and shows a temporal spread over the last 6000 years, with assemblages of trees during the Holocene Thermal Maximum (HTM; 8000-4000 BP) and the onset of the Medieval Warm Period (MWP, AD 900-1350). Annual tree growth and sample replication of peatland pines reflect moisture variations and long-term climate variability. The importance of extending the TRW chronologies should not therefore be underestimated as (1) climate records of comparable length and resolution do not exist for the Baltic region, but also as (2) a result of a widespread lack of detailed moisture proxies spanning several millennia. Our data clearly show that a 6000-yr, continuous pine chronology from the Baltic region is a realistic objective, and would doubtlessly fill a major geographic gap in an ecologically sensitive region located at the interface between the temperate and boreal vegetation zones.

Korean atomic bomb victims.

PubMed

Sasamoto, Yukuo

2009-01-01

After colonizing Korea, Japan invaded China, and subsequently initiated the Pacific War against the United States, Britain, and their allies. Towards the end of the war, U.S. warplanes dropped atomic bombs on Hiroshima and Nagasaki, which resulted in a large number of Koreans who lived in Hiroshima and Nagasaki suffering from the effects of the bombs. The objective of this paper is to examine the history of Korea atomic bomb victims who were caught in between the U.S., Japan, the Republic of Korea (South Korea) and the Democratic People's Republic of Korea (North Korea).

Systems, Shocks and Time Bombs

NASA Astrophysics Data System (ADS)

Winder, Nick

The following sections are included: * Introduction * Modelling strategies * Are time-bomb phenomena important? * Heuristic approaches to time-bomb phenomena * Three rational approaches to TBP * Two irrational approaches * Conclusions * References

Understanding the Chronology and Occupation Dynamics of Oversized Pit Houses in the Southern Brazilian Highlands.

PubMed

Gregorio de Souza, Jonas; Robinson, Mark; Corteletti, Rafael; Cárdenas, Macarena Lucia; Wolf, Sidnei; Iriarte, José; Mayle, Francis; DeBlasis, Paulo

2016-01-01

A long held view about the occupation of southern proto-Jê pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit House 1, Baggio I site (Cal. A.D. 1395-1650), Campo Belo do Sul, Santa Catarina state, Brazil. The stratigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Jê. As monumental pit houses start to be built, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamics and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America.

Understanding the Chronology and Occupation Dynamics of Oversized Pit Houses in the Southern Brazilian Highlands

PubMed Central

Gregorio de Souza, Jonas; Robinson, Mark; Corteletti, Rafael; Cárdenas, Macarena Lucia; Wolf, Sidnei; Iriarte, José; Mayle, Francis; DeBlasis, Paulo

2016-01-01

A long held view about the occupation of southern proto-Jê pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit House 1, Baggio I site (Cal. A.D. 1395–1650), Campo Belo do Sul, Santa Catarina state, Brazil. The stratigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Jê. As monumental pit houses start to be built, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamics and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America. PMID:27384341

A review of the chronologies and geomorphology of the aeolian landforms in the northwestern Negev dunefield (Israel)

NASA Astrophysics Data System (ADS)

Roskin, Joel

2015-04-01

The northwestern (NW) Negev Desert dunefield covering an area of only 1,300 km2, comprises the eastern end of the northern Sinai Peninsula - NW Negev erg and is probably the most densely dated dune body in the INQUA Dunes Atlas chronologic database. Over 230 luminescence ages (TL, IRSL, and mainly OSL) and radiocarbon dates have been retrieved over the past course of 20 years from calcic and sandy palaeosols serving as dune substrates, sand sheets, vegetated linear dunes (VLDs), fluvial deposits, and archaeological sites. Despite being from different deposit types and aeolian morphologies, and based on different methodologies, the chronologies usually show good compatibility. By reviewing and reassessing the significance of the Eastern Mediterranean INQUA Dunes Atlas chronologies, along with detailed stratigraphic, structural and geomorphologic data and understandings, the major, and possibly extreme, episodes of aeolian activity and stability are outlined. Repetitive chronostratigraphic sequences in VLDs indicate that this dune type, at least in the Negev, comprises a reliable recorder of main dune mobilization periods. This presentation demonstrates that certain combinations of research finds, using different OSL dating strategies and other regional and local late Quaternary records and in particular aeolian ones, are required assets for providing for acceptable local and regional palaeoclimatic interpretations. The distribution of the VLD chronologies points to rapid mobilization during the Heinrich 1 and Younger Dryas, characterized by powerful winds, though VLDs also form in late Holocene palaeoenvironments. Time slices illustrate the different sensitivities of the studied aeolian landforms to the source, availability, and supply of sediment; long- and short-term climate change, local human-induced environmental changes and also their joint effects, that enable evaluation of aeolian responses to future environmental and climate changes.

Radial ooids from Great Salt Lake (Utah) as paleoenvironmental archives: Insights from radiocarbon chronology and stable isotopes

NASA Astrophysics Data System (ADS)

Paradis, O. P.; Corsetti, F. A.; Bardsley, A.; Hammond, D. E.; Xu, X.; Walker, J. C.

2017-12-01

Ooids (laminated, carbonate coated grains) are ubiquitous in the geologic record in marine and lacustrine settings, and thus remain a common target for geochemical analysis to understand modern and ancient aqueous environments. However, the processes governing ooid formation remain unclear. Recently, radiocarbon dating has revealed that modern marine ooids grow slowly (Beaupre et al. 2015), and laboratory experiments have highlighted the importance of sediment transport and abrasion on net growth rates and ooid size (Trower et al. 2017). Ooid cortex structure includes micritic, tangential and/or radially oriented fabrics. Most modern marine ooids have tangential or micritic cortices, whereas many ancient ooids have radial cortices—thus, there is a need to understand how radial ooids in ancient rocks might inform us about their depositional environment. The Great Salt Lake (GSL), Utah, provides a unique environment to assess the growth rate of primary radial aragonitic ooids. Ooids collected near Antelope Island in the south arm of GSL were sieved, the 355-500 µm fraction was sequentially leached, and 14C of the evolved gas was analyzed to provide a time series of growth. The oldest inorganic carbon of this size fraction has an apparent 14C age of 6600 yr BP, with subsequent growth spanning over 6,000 years. Closed-basin lakes are particularly susceptible to a "reservoir effect" which results in anomalously old apparent radiocarbon ages. The 14C age of the modern dissolved inorganic carbon (DIC) of the south arm was measured to be 295 yr BP, a reservoir age comparable to estimates from lacustrine cave carbonates (McGee et al. 2012). Net growth rate of south arm ooids ranges between 0.01-0.025 µm per year. The δ13C of the outermost cortex suggests that the ooids resemble the modern DIC in the south arm water, suggesting ooids precipitate in equilibrium with lake water. Finer-scale structure in the δ13C of the ooid cortex through time suggests lake level changed

Growth process in an elephant tusk: Age estimations based on temporal variations in bomb-radiocarbon content

NASA Astrophysics Data System (ADS)

Nakamura, Toshio; Koike, Hiroko; Aizawa, Jun; Okuno, Mitsuru

2015-10-01

In this study, 14C analysis by accelerator mass spectrometry (AMS) was applied to age estimation based on temporal variations in bomb-produced-14C contents of a full elephant tusk registered at Kyushu University. The tusk measured 175 cm long and 13.8 cm in diameter at the root. Thirty tusk-fragment samples were used for 14C analysis with AMS to estimate the formation ages of different positions according to catalogued global 14C contents (F14C). The F14C value of the tip of the tusk suggested that the elephant was born around 1980, while that of the root suggested death around 1994, a lifespan of at least 14 years, rather shorter period than the average lifetime of an elephant (ca. 80 years). In addition, the F14C values of fragments collected along a cross-sectional line suggested that the outer part of the tusk formed first with inner parts being deposited gradually with growth.

Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century.

PubMed

Graven, Heather D

2015-08-04

Radiocarbon analyses are commonly used in a broad range of fields, including earth science, archaeology, forgery detection, isotope forensics, and physiology. Many applications are sensitive to the radiocarbon ((14)C) content of atmospheric CO2, which has varied since 1890 as a result of nuclear weapons testing, fossil fuel emissions, and CO2 cycling between atmospheric, oceanic, and terrestrial carbon reservoirs. Over this century, the ratio (14)C/C in atmospheric CO2 (Δ(14)CO2) will be determined by the amount of fossil fuel combustion, which decreases Δ(14)CO2 because fossil fuels have lost all (14)C from radioactive decay. Simulations of Δ(14)CO2 using the emission scenarios from the Intergovernmental Panel on Climate Change Fifth Assessment Report, the Representative Concentration Pathways, indicate that ambitious emission reductions could sustain Δ(14)CO2 near the preindustrial level of 0‰ through 2100, whereas "business-as-usual" emissions will reduce Δ(14)CO2 to -250‰, equivalent to the depletion expected from over 2,000 y of radioactive decay. Given current emissions trends, fossil fuel emission-driven artificial "aging" of the atmosphere is likely to occur much faster and with a larger magnitude than previously expected. This finding has strong and as yet unrecognized implications for many applications of radiocarbon in various fields, and it implies that radiocarbon dating may no longer provide definitive ages for samples up to 2,000 y old.

Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century

PubMed Central

Graven, Heather D.

2015-01-01

Radiocarbon analyses are commonly used in a broad range of fields, including earth science, archaeology, forgery detection, isotope forensics, and physiology. Many applications are sensitive to the radiocarbon (14C) content of atmospheric CO2, which has varied since 1890 as a result of nuclear weapons testing, fossil fuel emissions, and CO2 cycling between atmospheric, oceanic, and terrestrial carbon reservoirs. Over this century, the ratio 14C/C in atmospheric CO2 (Δ14CO2) will be determined by the amount of fossil fuel combustion, which decreases Δ14CO2 because fossil fuels have lost all 14C from radioactive decay. Simulations of Δ14CO2 using the emission scenarios from the Intergovernmental Panel on Climate Change Fifth Assessment Report, the Representative Concentration Pathways, indicate that ambitious emission reductions could sustain Δ14CO2 near the preindustrial level of 0‰ through 2100, whereas “business-as-usual” emissions will reduce Δ14CO2 to −250‰, equivalent to the depletion expected from over 2,000 y of radioactive decay. Given current emissions trends, fossil fuel emission-driven artificial “aging” of the atmosphere is likely to occur much faster and with a larger magnitude than previously expected. This finding has strong and as yet unrecognized implications for many applications of radiocarbon in various fields, and it implies that radiocarbon dating may no longer provide definitive ages for samples up to 2,000 y old. PMID:26195757

Resilience among Japanese atomic bomb survivors.

PubMed

Knowles, A

2011-03-01

The purpose of the study was to explore the experience of atomic bomb survivors from Hiroshima and Nagasaki. Never has the world experienced such extreme devastation as with the atomic bombings of Hiroshima and Nagasaki, Japan, in August 1945. Although significant quantitative research has been completed about the medical effects following radiation, the literature lacks qualitative exploration from a holistic health perspective. This was a qualitative descriptive study, using methods of narrative analysis, oral history and ethnography. The sample for this research included eight individuals who were exposed to the atomic bombings in Japan and currently reside in the United States. Findings provide insight to the resilience that the survivors exhibited immediately following the bomb, as well as throughout the 65 years following the event. From ethnographic data and interviews with survivors, a thematic structure was developed that depicts the essential elements of the atomic bomb experience. Two ways of being in the world followed the bombing: surviving and thriving, with resilience serving as a lever, allowing for fluid movement over time across the continuum. Individuals experiencing surviving exhibited anxiety about their personal and family members' health, expressed mistrust, and felt a stigma associated with being a survivor. For those who were thriving, peace activism, overcoming and forgiveness were typically displayed. Findings from this study add to the disaster nursing literature and highlight the role resilience plays in the atomic bomb survivors' life perspective. © 2011 The Author. International Nursing Review © 2011 International Council of Nurses.

Red China’s Capitalist Bomb: Inside the Chinese Neutron Bomb Program

DTIC Science & Technology

2015-01-01

developed an enhanced radiation weapon (ERW) but did not deploy it. ERWs, better known as “ neutron bombs,” are specialized nuclear weapons with...contemporary systems of concern. An ERW is a specialized nuclear weapon optimized to produce prompt radiation. Such a device emits neutrons with high...Council stated that China mastered “in succession the neutron bomb design technology and the nuclear weapon miniaturization technology.”10 This statement

The Somma-Vesuvius complex and the Phlaegrean Fields caldera: New chronological data of several eruptions of the Copper-Middle Bronze Age period

NASA Astrophysics Data System (ADS)

Passariello, Isabella; Lubritto, Carmine; D'Onofrio, Antonio; Guan, Yongjing; Terrasi, Filippo

2010-04-01

Radiocarbon dating of short-lived sample materials is a useful tool applied to date deposits of volcanic eruptions. Several archaeological sites discovered and excavated in Campania witnessed important volcanic eruptions, which occurred in the Copper and Middle Bronze Ages. These eruptions come from the Somma-Vesuvius complex and the Phlaegrean Fields caldera. At least four Plinian eruptions have been identified in the eruptive history of Somma-Vesuvius, interspersed by interplinian events, called protohistoric, which occurred between Avellino and Pompeii. At S. Paolo Belsito a stratigraphic sequence below Avellino and above the first two protohistoric events after Avellino were highlighted; while Nola (Naples) gives new information on the chronology of Avellino. Sites like Caivano and Gricignano D'Aversa, involved by the Agnano 3, Paleoastroni 2 and Agnano Monte Spina eruptions were highlighted and investigated. In this work, we want to clarify the chronology of some eruptions by comparing our results with previous data. Charcoal, bone and seed samples were collected, treated and measured at the CIRCE laboratory in Caserta.

Should We Let the Bomb Spread

DTIC Science & Technology

2016-11-01

in national security policy formulation. iii v Strategic Studies Institute and U.S. Army War College Press SHOULD WE LET THE BOMB SPREAD? Henry D...the Bomb Don’t Think “More Is Better”..............25 W. Seth Carus 3. “At All Costs”: The Destructive Consequences of Anti-Proliferation Policy...In 1966, Leonard Beaton, a journalist and strategic scholar, published a short book that asked: Must the bomb spread?1 Mr. Beaton’s query

Marine radiocarbon reservoir age variation in Donax obesulus shells from northern Peru: late Holocene evidence for extended El Niño

USGS Publications Warehouse

Etayo-Cadavid, Miguel F.; Andrus, C. Fred T.; Jones, Kevin B.; Hodgins, Gregory W. L.; Sandweiss, Daniel H.; Uceda-Castillo, Sandiago; Quilter, Jeffrey

2013-01-01

For at least 6 m.y., El Niño events have posed the greatest environmental risk on the Peruvian coast. A better understanding of El Niño is essential for predicting future risk and growth in this tropical desert. To achieve this we analyzed archaeological and modern pre-bomb shells from the surf clam Donax for the radiocarbon reservoir effect (ΔR) to characterize late Holocene coastal upwelling conditions in northern Peru (8°14′S). Mean ΔR values from these shells suggest that modern upwelling conditions in this region were likely established between A.D. 539 and A.D. 1578. Our radiocarbon data suggest that upwelling conditions ca. A.D. 539 were less intense than those in modern times. The observed coastal water enrichment in 14C may be consequence of frequent strong El Niño events or extended El Niño–like conditions. These ΔR-inferred marine conditions are in agreement with proposed extended El Niño activity in proxy and archaeological records of ca. A.D. 475–530. Extended El Niño conditions have been linked to political destabilization, societal transformation, and collapse of the Moche civilization in northern Peru. A return to such conditions would have significant impacts on the dense population of this region today and in the near future.

A case of early Wisconsinan ;over-chill;: New radiocarbon evidence for early extirpation of western camel (Camelops hesternus) in eastern Beringia

NASA Astrophysics Data System (ADS)

Zazula, Grant D.; MacPhee, Ross D. E.; Southon, John; Nalawade-Chavan, Shweta; Reyes, Alberto V.; Hewitson, Susan; Hall, Elizabeth

2017-09-01

There are comparatively few fossils that document the presence of the Pleistocene western camel (Camelops hesternus) in the unglaciated regions of Alaska and Yukon, northwestern North America (eastern Beringia). It has been previously reported on the basis of stratigraphic and radiocarbon data that this species was present within this region from the Sangamonian interglaciation (Marine Isotope Stage (MIS) 5) through the Last Glacial Maximum (LGM, MIS 2). However, the continued presence of western camel through the LGM is at odds with its ecological preferences as inferred from more southerly parts of the continent. Here we report 43 new radiocarbon dates on 34 western camel fossils from Alaska and Yukon, including specimens that have been dated previously. To minimize exogenous carbon contamination, we utilized either ultrafiltered collagen or single amino acid (hydroxyproline) methodologies in conducting the analyses. All samples, including previously reported specimens with finite ages, yielded ages that were either non-finite or close to the effective limit of radiocarbon dating. These results indicate that dates implying local presence of western camels in Alaska and Yukon during full-glacial conditions of MIS 2 are erroneous by as much as several tens of millennia, probably because of carbon contamination from glue or varnish used in fossil preparation and conservation. The revised radiocarbon chronology, together with other evidence, indicates that western camels were only able to occupy eastern Beringia only during Pleistocene interglaciations such as MIS 5, when forests and shrublands became the dominant regional biomes. The subsequent transition to cold, arid full-glacial conditions during the early Wisconsinan glaciation (MIS 4) around 75 000 years ago created unfavorable environmental conditions, eliminated browse, and led to their local extirpation in eastern Beringia. After their complete population loss in the Arctic and Subarctic, the range of

Future population of atomic bomb survivors in Nagasaki.

PubMed

Yokota, Kenichi; Mine, Mariko; Shibata, Yoshisada

2013-01-01

The Nagasaki University Atomic Bomb Survivor Database, which was established in 1978 for elucidating the long-term health effects of the atomic bombing, has registered since 1970 about 120,000 atomic bomb survivors with a history of residence in Nagasaki city. Since the number of atomic bomb survivors has steadily been decreasing, prediction of future population is important for planning future epidemiologic studies, and we tried to predict the population of atomic bomb survivors in Nagasaki city from 2008 to 2030. In addition, we evaluated our estimated population comparing with the actual number from 2008 to 2011.

The radiocarbon hydroxyl technique

NASA Technical Reports Server (NTRS)

Campbell, Malcolm J.; Sheppard, John C.

1994-01-01

The Radiocarbon Technique depends upon measuring the rate of oxidation of CO in an essentially unperturbed sample of air. The airborne technique is slightly different. Hydroxyl concentrations can be calculated directly; peroxyl concentrations can be obtained by NO doping.

The importance of independent chronology in integrating records of past climate change for the 60-8 ka INTIMATE time interval

NASA Astrophysics Data System (ADS)

Brauer, Achim; Hajdas, Irka; Blockley, Simon P. E.; Bronk Ramsey, Christopher; Christl, Marcus; Ivy-Ochs, Susan; Moseley, Gina E.; Nowaczyk, Norbert N.; Rasmussen, Sune O.; Roberts, Helen M.; Spötl, Christoph; Staff, Richard A.; Svensson, Anders

2014-12-01

This paper provides a brief overview of the most common dating techniques applied in palaeoclimate and palaeoenvironmental studies including four radiometric and isotopic dating methods (radiocarbon, 230Th disequilibrium, luminescence, cosmogenic nuclides) and two incremental methods based on layer counting (ice layer, varves). For each method, concise background information about the fundamental principles and methodological approaches is provided. We concentrate on the time interval of focus for the INTIMATE (Integrating Ice core, MArine and TErrestrial records) community (60-8 ka). This dating guide addresses palaeoclimatologists who aim at interpretation of their often regional and local proxy time series in a wider spatial context and, therefore, have to rely on correlation with proxy records obtained from different archives from various regions. For this reason, we especially emphasise scientific approaches for harmonising chronologies for sophisticated and robust proxy data integration. In this respect, up-to-date age modelling techniques are presented as well as tools for linking records by age equivalence including tephrochronology, cosmogenic 10Be and palaeomagnetic variations. Finally, to avoid inadequate documentation of chronologies and assure reliable correlation of proxy time series, this paper provides recommendations for minimum standards of uncertainty and age datum reporting.

Seismogram offers insight into Oklahoma City bombing

NASA Astrophysics Data System (ADS)

Holzer, Thomas L.; Fletcher, Joe B.; Fuis, Gary S.; Ryberg, Trond; Brocher, Thomas M.; Dietel, Christopher M.

The terrorist bombing of the Alfred P. Murrah Federal Building in Oklahoma City on April 19, 1995, generated seismic waves that were recorded on two permanent seismographs about 7 and 26 km away from the bombing. The seismogram recorded at 26 km shows two low-frequency wave trains, discrete sets of oscillatory signals, that begin about 10 s apart. Public release of this record prompted speculation that each wave train was caused by a different energy source. On May 23, 1995, the U.S. Geological Survey monitored the demolition of the bomb-ravaged Federal Building with portable seismographs (Figure 1). Two wave trains were picked up again. The recordings indicate that the wave trains during both the bombing and demolition represent seismic waves traveling at different velocities. We conclude that the two wave trains recorded during the bombing are consistent with a single impulsive energy source.

Optimization of simultaneous tritium–radiocarbon internal gas proportional counting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.

Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill ofmore » P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium counting efficiency while minimizing radiocarbon beta decay interference.« less

Late Quaternary sedimentological and climate changes at Lake Bosumtwi Ghana: new constraints from laminae analysis and radiocarbon age modeling

USGS Publications Warehouse

Shanahan, Timothy M.; Beck, J. Warren; Overpeck, Jonathan T.; McKay, Nicholas P.; Pigati, Jeffrey S.; Peck, John A.; Scholz, Christopher A.; Heil, Clifford W.; King, John W.

2012-01-01

The Lake Bosumtwi sediment record represents one of the longest and highest-resolution terrestrial records of paleoclimate change available from sub-Saharan Africa. Here we report a new sediment age model framework for the last ~ 45 cal kyr of sedimentation using a combination of high-resolution radiocarbon dating, Bayesian age-depth modeling and lamination counting. Our results highlight the practical limits of these methods for reducing age model uncertainties and suggest that even with very high sampling densities, radiocarbon uncertainties of at least a few hundred years are unavoidable. Age model uncertainties are smallest during the Holocene (205 yr) and the glacial (360 yr) but are large at the base of the record (1660 yr), due to a combination of decreasing sample density, larger calibration uncertainties and increases in radiocarbon age scatter. For portions of the chronology older than ~ 35 cal kyr, additional considerations, such as the use of a low-blank graphitization system and more rigorous sample pretreatment were necessary to generate a reliable age depth model because of the incorporation of small amounts of younger carbon. A comparison of radiocarbon age model results and lamination counts over the time interval ~ 15–30 cal kyr agree with an overall discrepancy of ~ 10% and display similar changes in sedimentation rate, supporting the annual nature of sediment laminations in the early part of the record. Changes in sedimentation rates reconstructed from the age-depth model indicate that intervals of enhanced sediment delivery occurred at 16–19, 24 and 29–31 cal kyr, broadly synchronous with reconstructed drought episodes elsewhere in northern West Africa and potentially, with changes in Atlantic meridional heat transport during North Atlantic Heinrich events. These data suggest that millennial-scale drought events in the West African monsoon region were latitudinally extensive, reaching within several hundred kilometers of the Guinea coast

Triggering soft bombs at the LHC

NASA Astrophysics Data System (ADS)

Knapen, Simon; Griso, Simone Pagan; Papucci, Michele; Robinson, Dean J.

2017-08-01

Very high multiplicity, spherically-symmetric distributions of soft particles, with p T ˜ few×100 MeV, may be a signature of strongly-coupled hidden valleys that exhibit long, efficient showering windows. With traditional triggers, such `soft bomb' events closely resemble pile-up and are therefore only recorded with minimum bias triggers at a very low efficiency. We demonstrate a proof-of-concept for a high-level triggering strategy that efficiently separates soft bombs from pile-up by searching for a `belt of fire': a high density band of hits on the innermost layer of the tracker. Seeding our proposed high-level trigger with existing jet, missing transverse energy or lepton hardware-level triggers, we show that net trigger efficiencies of order 10% are possible for bombs of mass several × 100 GeV. We also consider the special case that soft bombs are the result of an exotic decay of the 125 GeV Higgs. The fiducial rate for `Higgs bombs' triggered in this manner is marginally higher than the rate achievable by triggering directly on a hard muon from associated Higgs production.

Ocean science: Radiocarbon variability in the western North Atlantic during the last deglaciation

USGS Publications Warehouse

Robinson, L.F.; Adkins, J.F.; Keigwin, L.D.; Southon, J.; Fernandez, D.P.; Wang, S.-L.; Scheirer, D.S.

2005-01-01

We present a detailed history of glacial to Holocene radiocarbon in the deep western North Atlantic from deep-sea corals and paired benthic-planktonic foraminifera. The deglaciation is marked by switches between radiocarbon-enriched and -depleted waters, leading to large radiocarbon gradients in the water column. These changes played an important role in modulating atmospheric radiocarbon. The deep-ocean record supports the notion of a bipolar seesaw with increased Northern-source deep-water formation linked to Northern Hemisphere warming and the reverse. In contrast, the more frequent radiocarbon variations in the intermediate/deep ocean are associated with roughly synchronous changes at the poles.

Researching the Oklahoma City bombing.

PubMed

Piotrowski, C; Perdue, B

1995-12-01

The authors present a literature retrieval strategy for investigators who plan to conduct research on the Oklahoma City bombing. To facilitate a comprehensive review of the scholarly research on disasters, mass emergencies, and terrorism, a multidatabase search strategy is strongly encouraged. Secondly, a wealth of current information and data on the bombing are available on "popular" and "news" files.

Bomb Threats Taking Financial Toll

ERIC Educational Resources Information Center

Bowman, Darcia Harris

2004-01-01

Despite all its efforts to crack down on the bomb scares that disrupted classes again and again in 2003, North Carolina's Orange County district fell victim to yet another false alarm this school year, 2004. For some schools, bomb threats have become more routine than fire drills, with each incident ringing up multi-thousand-dollar tabs for…

Atmospheric rivers and bombs

NASA Astrophysics Data System (ADS)

Zhu, Yong; Newell, Reginald E.

1994-09-01

Filamentary structure is a common feature of atmospheric water vapor transport; the filaments may be termed “atmospheric rivers” because some carry as much water as the Amazon [Newell et al., 1992]. An extratropical cyclone whose central pressure fall averages at least 1 hPa hr-1 for 24 hours is known in meteorology as a “bomb” [Sanders and Gyakum, 1980]. We report here an association between rivers and bombs. When a cyclonic system is penetrated by a river, the cyclonic center moves to be close to the position occupied by the leading edge of the river twelve hours previously and the central pressure falls. If the river then moves away from the cyclone, the central pressure rises. Based on a pilot study of pressure fall and water vapor flux convergence for two winter months, the cause of the explosive deepening appears to be latent heat liberation. This is substantiated by composite maps of seven Atlantic and seven Pacific bombs which show that the flux convergence near the bomb center has a comma cloud signature. The observed association may be useful in forecasting 12-hour direction of motion and pressure change of rapidly developing cyclonic systems; the incorporation of better moisture data into numerical forecasting models may be the reason for the reported increase of skill in the prediction of bombs in recent years.

Differential extraction of radiocarbon associated with soil biomass and humus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsao, C.W.; Bartha, R.

To detect the humification of organic compounds in soil that bypasses biomass incorporation, selective extraction procedures for radiocarbon from soil biomass and humus were evaluated. Following the incubation of [sup 14]C-glucose and [sup 14]C-benzoate in soil, fumigation--0.5 M K[sub 2]SO[sub 4] extraction and 0.15 M Na[sub 4]P[sub 2]O[sub 7] extraction selectively removed biomass-associated and humus-associated radiocarbon, respectively. Applying the recovery correction of 3.4[times] to biomass and 3.5[times] to humus, radiocarbon balances of 95 to 107% were obtained during a time window following the degradation of these substrates. Negligible overlap between the extractions renders the technique suitable for investigating the fatemore » of organics that, through cometabolism, attain unusual radiocarbon distributions in soil.« less

Use of Stored Carbon Reserves in Growth of Temperate Tree Roots and Leaf Buds: Analyses Using Radiocarbon Measurements and Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaudinski, Julia B.; Torn, Margaret S.; Riley, W. J.

2009-01-01

Characterizing the use of C reserves in trees is important for understanding stress responses, impacts of asynchrony between photosynthesis and growth demand, and isotopic exchanges in plant dynamic studies. Using an inadvertent, whole ecosystem radiocarbon (14C) exposure in a temperate deciduous oak forest and numerical modeling, we calculated that the mean age of stored C used to grow leaf buds and new fine root tissue is 0.5-1.0 y. The mean age of stored C used to grow new roots was about 0.7 y across a range of realistic values of 14C inputs to the system. The amount of stored Cmore » used on an annual basis to grow fine roots was between 15 and 55% of total root growth, with the range defined by the assumed 14C input profile. We estimate the annually-averaged mean age of C in new root tissues is 1-5 months. Therefore, accounting for storage C use in isotope root models may be unnecessary in all but the fastest cycling root populations (i.e., mean age <1 y). Consistent with the whole ecosystem labeling results, we found, using "bomb-14C," that the mean C age of new root tissues in three additional forest sites (one deciduous, two coniferous) was less than 2 years. We conclude that in many ecosystem types, growth from stored C is insufficient to impact bomb-14C based estimates of long root lifetimes.« less

Age estimations of wild pallid sturgeon (Scaphirhynchus albus, Forbes & Richardson 1905) based on pectoral fin spines, otoliths and bomb radiocarbon: inferences on recruitment in the dam-fragmented Missouri River

USGS Publications Warehouse

Braaten, P. J.; Campana, S. E.; Fuller, D. B.; Lott, R. D.; Bruch, R. M.; Jordan, G. R.

2015-01-01

An extant stock of wild pallid sturgeon Scaphirhynchus albus persists in the fragmented upper Missouri River basin of Montana and North Dakota. Although successful spawning and hatch of embryos has been verified, long-term catch records suggest that recruitment has not occurred for several decades as the extant stock lacks juvenile size classes and is comprised exclusively of large, presumably old individuals. Ages of 11 deceased (death years 1997–2007) wild S. albus (136–166 cm fork length) were estimated based on pectoral fin spines, sagittal otoliths and bomb radiocarbon (14C) assays of otoliths to test the hypothesis that members of this stock are old and to provide inferences on recruitment years that produced the extant stock. Age estimations based on counts of presumed annuli were about 2 years greater for otoliths (mean = 51 years, range = 43–57 years) than spines (mean = 49 years, range = 37–59 years). Based on 14C assays, confirmed birth years for all individuals occurred prior to 1957, thus establishing known longevity of at least 50 years. Estimated age based on presumed otolith annuli for one S. albus was validated to at least age 49. Although 14C assays confirmed pre-1957 birth years for all S. albus, only 56% of estimated ages from spines and 91% of estimated ages from otoliths depicted pre-1957 birth years. Both ageing structures were subject to under-ageing error (up to 15 years). Lack of or severe curtailment of S. albus recruitment in the upper Missouri River basin since the mid-1950s closely parallels the 1953–1957 timeframe when a mainstem reservoir was constructed and started to fill. This reservoir may function as a system-wide stressor to diminish recruitment success of S. albus in the upper Missouri River basin.

Selenium impacts on fish: an insidious time bomb

Treesearch

A. Dennis Lemly

1999-01-01

A selenium time bomb situation is developing in the United States and elsewhere that may result in substantial impacts on fish populations. The selenium time bomb has three components: (1) high food-chain bioaccumulation; (2) steep toxic response curve for fish; and (3) insidious mode of toxicity. If the threshold for selenium toxicity is exceeded, the time bomb...

Mauna Loa eruptive history—The preliminary radiocarbon record

NASA Astrophysics Data System (ADS)

Lockwood, John P.

Radiocarbon dating of charcoal from beneath lava flows of Mauna Loa has provided the most detailed prehistoric eruptive chronology of any volcano on Earth. Three hundred and fifty-five 14C dates have been reviewed, stratigraphically contradictory dates have been rejected, and multiple dates on single flows averaged to give "reliable" ages on 170 separate lava flows (about 35% of the total number of prehistoric Mauna Loa flows mapped to date). The distribution of these ages has revealed fundamental variations in the time and place of Mauna Loa eruptive activity, particularly for Holocene time. As lava flow activity from Mauna Loa's summit waxes, activity on the rift zones wanes. A cyclic model is proposed which involves a period of concentrated summit shield-building activity associated with long-lived lava lakes and frequent overflows of pahoehoe lavas on the north and southeast flanks. At this time, compressive stresses across Mauna Loa's rift zones are relatively high, inhibiting eruptions in these areas. This period is then followed by a relaxation of stresses across Mauna Loa's rift zones and a long period of frequent rift zone eruptions as magma migrates downrift. This change of eruptive style is marked by summit caldera collapse (possibly associated with massive eruptions of picritic lavas low on the rift zones). Concurrent with this increased rift zone activity, the summit caldera is gradually filled by repeated summit eruptions, stress across the rift zones increases, magma rises more easily to the summit, rift activity wanes, and the cycle repeats itself. Two such cycles are suggested within the late Holocene, each lasting 1,500-2,000 years. Earlier evidence for such cycles is obscure. Mauna Loa appears to have been quiescent between 6-7 ka, for unknown reasons. A period of increased eruptive activity marked the period 8-11 ka, coincident with the Pleistocene-Holocene boundary. Other volcanoes on the Island of Hawaii for which (limited) radiocarbon dating

Hα features with hot onsets. I. Ellerman bombs

NASA Astrophysics Data System (ADS)

Rutten, R. J.

2016-05-01

Ellerman bombs are transient brightenings of the wings of the Balmer lines that uniquely mark reconnection in the solar photosphere. They are also bright in strong Ca II and ultraviolet lines and in ultraviolet continua, but they are not visible in the optical continuum and the Na I D and Mg I b lines. These discordant visibilities invalidate all published Ellerman bomb modeling. I argue that the assumption of Saha-Boltzmann lower-level populations is informative to estimate bomb-onset opacities for these diverse diagnostics, even and especially for Hα, and employ such estimates to gauge the visibilities of Ellerman bomb onsets in all of them. They constrain Ellerman bomb formation to temperatures 10 000-20 000 K and hydrogen densities around 1015 cm-3. Similar arguments likely hold for Hα visibility in other transient phenomena with hot and dense onsets.

Marine radiocarbon reservoir corrections (∆R) for Chesapeake Bay and the Middle Atlantic Coast of North America

NASA Astrophysics Data System (ADS)

Rick, Torben C.; Henkes, Gregory A.; Lowery, Darrin L.; Colman, Steven M.; Culleton, Brendan J.

2012-01-01

Radiocarbon dates from known age, pre-bomb eastern oyster (Crassostrea virginica) shells provide local marine reservoir corrections (∆R) for Chesapeake Bay and the Middle Atlantic coastal area of eastern North America. These data suggest subregional variability in ∆R, ranging from 148 ± 46 14C yr on the Potomac River to - 109 ± 38 14C yr at Swan Point, Maryland. The ∆R weighted mean for the Chesapeake's Western Shore (129 ± 22 14C yr) is substantially higher than the Eastern Shore (- 88 ± 23 14C yr), with outer Atlantic Coast samples falling between these values (106 ± 46 and 2 ± 46 14C yr). These differences may result from a combination of factors, including 14C-depleted freshwater that enters the bay from some if its drainages, 14C-depleted seawater that enters the bay at its mouth, and/or biological carbon recycling. We advocate using different subregional ∆R corrections when calibrating 14C dates on aquatic specimens from the Chesapeake Bay and coastal Middle Atlantic region of North America.

Yale and the Atomic Bomb Casualty Commission.

PubMed Central

Bowers, J. Z.

1983-01-01

This is a description, based largely on personal discussions, of the contributions of men from the Yale University School of Medicine to the saga of the immediate and long-term studies on the medical effects of the atomic bombs at Hiroshima and Nagasaki. They played key roles in the immediate studies of bomb effects, in the creation of long-term studies of delayed effects, and in elevating the Atomic Bomb Casualty Commission after 1955 to a position of excellence in its studies and relations with the Japanese. The accumulation of the information presented in this paper derives from research for the preparation of the history of the Atomic Bomb Casualty Commission. In 1975, the commission was passed to Japanese leadership as the Radiation Effects Research Foundation. PMID:6349145

Britain's bomb

NASA Astrophysics Data System (ADS)

Corfield, Richard

2012-10-01

On the 60th anniversary of Britain's first nuclear test, Richard Corfield explores how Operation Hurricane - the British effort to develop the atomic bomb in the 1940s and 1950s - compares with states such as Iran that today wish to have such devices.

Preventing fatalities in building bombings: what can we learn from the Oklahoma City bombing?

PubMed

Glenshaw, Mary T; Vernick, Jon S; Li, Guohua; Sorock, Gary S; Brown, Sheryll; Mallonee, Sue

2007-07-01

Bombings are an increasing threat to the public's health. Descriptive studies of blast injuries have been published, but these injuries have not been studied using analytical epidemiological methods. This study assesses factors associated with fatality risk among individuals exposed to the 1995 Oklahoma City bombing. Retrospective case-control analysis using multivariable logistic regression. Odds ratios (OR) of fatality are calculated among occupants of the Alfred P. Murrah Federal Building on April 19, 1995. Of the 348 occupants exposed, 163 (46.8%) were fatally injured. Fatality risk was greatest in the collapsed region of the building (adjusted OR 176.7, 95% confidence interval [CI] 65.9-474.2). Age > or =40 was also associated with a significantly increased risk of fatality (OR 3.7, 95% CI 1.4-9.8). Among people found in the noncollapsed region of the building, employees' status compared to a visitor's or child's status was protective (OR 0.13, 95% CI 0.01-1.3). Structural collapse is the most important risk factor for fatality in a building bombing. Progressive collapse may be prevented through more supportive building design. Protection of vulnerable building occupants can be improved by placement of relevant facilities in more structurally reinforced areas. Regular evacuation training of personnel and clear egress routes may also reduce fatality in a building bombing.

Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774-775

NASA Astrophysics Data System (ADS)

Rakowski, Andrzej Z.; Krąpiec, Marek; Huels, Mathias; Pawlyta, Jacek; Dreves, Alexander; Meadows, John

2015-10-01

Evidence of a rapid increase in atmospheric radiocarbon (14C) content in AD 774-775 was presented by Miyake et al. (2012), who observed an increase of about 12‰ in the 14C content in annual tree rings from Japanese cedar. Usoskin et al. (2013) report a similar 14C spike in German oak, and attribute it to exceptional solar activity. If this phenomenon is global in character, such rapid changes in 14C concentration may affect the accuracy of calibrated dates, as the existing calibration curve is composed mainly of decadal samples. Single-year samples of dendro-chronologically dated tree rings of deciduous oak (Quercus robur) from Kujawy, a village near Krakow (SE Poland), spanning the years AD 765-796, were collected and their 14C content was measured using the AMS system in the Leibniz Laboratory. The results clearly show a rapid increase of 9.2 ± 2.1‰ in the 14C concentration in tree rings between AD 774 and AD 775, with maximum Δ14C = 4.1 ± 2.3‰ noted in AD 776.

The 3.6 ka Aniakchak tephra in the Arctic Ocean: a constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea

NASA Astrophysics Data System (ADS)

Pearce, Christof; Varhelyi, Aron; Wastegård, Stefan; Muschitiello, Francesco; Barrientos, Natalia; O'Regan, Matt; Cronin, Thomas M.; Gemery, Laura; Semiletov, Igor; Backman, Jan; Jakobsson, Martin

2017-04-01

The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenland. This large geographic distribution, combined with the fact that the eruption is relatively well constrained in time using radiocarbon dating of lake sediments and annual layer counts in ice cores, makes it an excellent stratigraphic marker for dating and correlating mid-late Holocene sediment and paleoclimate records. This study presents the outcome of a targeted search for the Aniakchak tephra in a marine sediment core from the Arctic Ocean, namely Core SWERUS-L2-2-PC1 (2PC), raised from 57 m water depth in Herald Canyon, western Chukchi Sea. High concentrations of tephra shards, with a geochemical signature matching that of Aniakchak ash, were observed across a more than 1.5 m long sediment sequence. Since the primary input of volcanic ash is through atmospheric transport, and assuming that bioturbation can account for mixing up to ca. 10 cm of the marine sediment deposited at the coring site, the broad signal is interpreted as sustained reworking at the sediment source input. The isochron is therefore placed at the base of the sudden increase in tephra concentrations rather than at the maximum concentration. This interpretation of major reworking is strengthened by analysis of grain size distribution which points to ice rafting as an important secondary transport mechanism of volcanic ash. Combined with radiocarbon dates on mollusks in the same sediment core, the volcanic marker is used to calculate a marine radiocarbon reservoir age offset ΔR = 477 ± 60 years. This relatively high value may be explained by the major influence of typically carbon-old Pacific waters, and it agrees well with recent estimates of ΔR along the northwest Alaskan coast

Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania.

PubMed

Tryon, Christian A; Lewis, Jason E; Ranhorn, Kathryn L; Kwekason, Amandus; Alex, Bridget; Laird, Myra F; Marean, Curtis W; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z P

2018-01-01

The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46-42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39-34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa.

Development of a Dirigible Bomb

DTIC Science & Technology

1943-04-15

X - ¥ control for all future high-angle dirigible bombs in spite of the instrumental complications involved. /. two gyro system consisting of t...ts found thet the bomb wos in roll equilibrium £.t aero roll orientetion . Moreover, these roll equilibrium positions ire stt-ble ss indicated by...tirflow giving rise to voll torques in the seme direction fcs roll dis- placements from the «ero orientetion , the roll equilibrium found for equel pitch

Bigeye Bomb: Unresolved Development Issues

DTIC Science & Technology

1989-08-11

the lethal agent formed inside the Bigeye bomb) at the purity or equivalent- biotoxicity level required by the Test and Eval- uation Master Plan (TEMP...during the 5 through 30-second period after mixing starts, with- out specifying either wheit the required purity or equivalent biotoxicity level should...revision of the purity or equivalent biotoxicity requirement. However, we believe that a bomb that produces lethal agent at the required purity level for 1

49 CFR 173.160 - Bombs, smoke, non-explosive (corrosive).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Bombs, smoke, non-explosive (corrosive). 173.160 Section 173.160 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.160 Bombs, smoke, non-explosive (corrosive). Bombs, smoke, non-explosive may...

49 CFR 173.160 - Bombs, smoke, non-explosive (corrosive).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Bombs, smoke, non-explosive (corrosive). 173.160 Section 173.160 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.160 Bombs, smoke, non-explosive (corrosive). Bombs, smoke, non-explosive may...

49 CFR 173.160 - Bombs, smoke, non-explosive (corrosive).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Bombs, smoke, non-explosive (corrosive). 173.160 Section 173.160 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.160 Bombs, smoke, non-explosive (corrosive). Bombs, smoke, non-explosive may...

49 CFR 173.160 - Bombs, smoke, non-explosive (corrosive).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Bombs, smoke, non-explosive (corrosive). 173.160 Section 173.160 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.160 Bombs, smoke, non-explosive (corrosive). Bombs, smoke, non-explosive may...

49 CFR 173.160 - Bombs, smoke, non-explosive (corrosive).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Bombs, smoke, non-explosive (corrosive). 173.160 Section 173.160 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.160 Bombs, smoke, non-explosive (corrosive). Bombs, smoke, non-explosive may...

Nonannual tree rings in a climate-sensitive Prioria copaifera chronology in the Atrato River, Colombia.

PubMed

Herrera-Ramirez, David; Andreu-Hayles, Laia; Del Valle, Jorge I; Santos, Guaciara M; Gonzalez, Paula L M

2017-08-01

In temperate climates, tree growth dormancy usually ensures the annual nature of tree rings, but in tropical environments, determination of annual periodicity can be more complex. The purposes of the work are as follows: (1) to generate a reliable tree-ring width chronology for Prioria copaifera Griseb. (Leguminoceae), a tropical tree species dwelling in the Atrato River floodplains, Colombia; (2) to assess the climate signal recorded by the tree-ring records; and (3) to validate the annual periodicity of the tree rings using independent methods. We used standard dendrochronological procedures to generate the P. copaifera tree-ring chronology. We used Pearson correlations to evaluate the relationship of the chronology with the meteorological records, climate regional indices, and gridded precipitation/sea surface temperature products. We also evaluated 24 high-precision 14 C measurements spread over a range of preselected tree rings, with assigned calendar years by dendrochronological techniques, before and after the bomb spike in order to validate the annual nature of the tree rings. The tree-ring width chronology was statistically reliable, and it correlated significantly with local records of annual and October-December (OND) streamflow and precipitation across the upper river watershed (positive), and OND temperature (negative). It was also significantly related to the Oceanic Niño Index, Pacific Decadal Oscillation, and the Southern Oscillation Index, as well as sea surface temperatures over the Caribbean and the Pacific region. However, 14 C high-precision measurements over the tree rings demonstrated offsets of up to 40 years that indicate that P. copaifera can produce more than one ring in certain years. Results derived from the strongest climate-growth relationship during the most recent years of the record suggest that the climatic signal reported may be due to the presence of annual rings in some of those trees in recent years. Our study alerts about

Bomb fall-out 236U as a global oceanic tracer using an annually resolved coral core

PubMed Central

Winkler, Stephan R.; Steier, Peter; Carilli, Jessica

2012-01-01

Anthropogenic 236U (t½=23.4 My) is an emerging isotopic ocean tracer with interesting oceanographic properties, but only with recent advances in accelerator mass spectrometry techniques is it now possible to detect the levels from global fall-out of nuclear weapons testing across the water column. To make full use of this tracer, an assessment of its input into the ocean over the past decades is required. We captured the bomb-pulse of 236U in an annually resolved coral core record from the Caribbean Sea. We thereby establish a concept which gives 236U great advantage – the presence of reliable, well-resolved chronological archives. This allows studies of not only the present distribution pattern, but gives access to the temporal evolution of 236U in ocean waters over the past decades. PMID:23564966

Volcanic plume and bomb field masses from thermal infrared camera imagery

NASA Astrophysics Data System (ADS)

Harris, A. J. L.; Delle Donne, D.; Dehn, J.; Ripepe, M.; Worden, A. K.

2013-03-01

Masses erupted during normal explosions at Stromboli volcano (Italy) are notoriously difficult to measure. We present a method that uses thermal infrared video for cooling bomb fields to obtain the total power emitted by all hot particles emitted during an explosion. A given mass of magma (M) will emit a finite amount of thermal power, defined by M cp(Te-T0), cp and Te being magma specific heat capacity and temperature, and T0 being ambient temperature. We use this relation to convert the total power emitted by the bomb field to the mass required to generate that power. To do this we extract power flux curves for the field and integrate this through time to obtain total power (E). This is used to estimate mass (Q) in Q=E/cp(Te-T0). When applied to individual bombs we obtain masses of between 1 and 9 kg per bomb, or a volume of 970 and 6500 cm3. These volumes equate to spheres with diameters 12 and 27 cm. For the entire bomb field we obtain volumes of 7-28 m3. We calculate masses for 32 eruptions and obtain typical bomb masses of between 103 and 104 kg per eruption. In addition, we estimate that between 102 and 103 kg of gas and ash are emitted as part of a mixed plume of bombs, gas and ash. We identify two types of eruption on the basis of the erupted bomb masses and the ratio of the plume's gas-and-ash component to the bomb component. The first type is bomb-dominated, is characterized by bomb masses of 104 kg and has ash-gas/ bomb ratios of ˜0.02. The second type is ash-and-gas dominated, is characterized by erupted bomb masses of 103 kg and has ash-gas/bomb ratios of around one, and as high as two. There is no correlation between the quantity of bombs and quantity of gas-ash erupted. In addition, while source pressure for each explosion correlates with the quantity of gas and ash erupted, the mass of bombs emitted varies independently of pressure.

Life-bombing-injury-life: a qualitative follow-up study of Oklahoma City bombing survivors with TBI.

PubMed

Sample, Pat L; Greene, David; Johns, Nikole R

2012-01-01

To learn about and come to an understanding of the recovery process and outcomes experienced by the survivors of the 1995 Oklahoma City bombing, who sustained a traumatic brain injury (TBI) along with other injuries in the blast. A phenomenological study was conducted using in-person interviews, document and video-tape review, internet communication and researcher journals as the primary data set. A total of 20 of the 46 bombing survivors with TBI (44%) agreed to be a part of the study. The data collection process focused on stories about service needs, services accessed and long-term outcomes of the participants. The researchers' data analysis yielded four themes (Trauma-Healing-Support; What TBI?; How I went back to work and life; Now I really need assistance!) that represented the content and meanings of the interviews and supplemental data. A common thread running through the interviews of survivors with TBI was their portrayal of life-long medical, emotional, vocational and residential needs since the bombing. What they experienced in the months--extending into years--after the bombing was beyond their own anticipation and that of their families and healthcare professionals.

Hiroshima: Perspectives on the Atomic Bombing.

ERIC Educational Resources Information Center

Cheng, Amy

In this curriculum module students analyze both U.S. and Japanese perspectives of the atomic bombing of Hiroshima. The activities integrate Howard Gardner's work on multiple intelligences. The module is recommended as a supplement to textbook coverage of the war in the Pacific and of the atomic bombing of Hiroshima. It can be used to support both…

The Middle to Upper Paleolithic transition: dating, stratigraphy, and isochronous markers.

PubMed

Blockley, S P E; Ramsey, C Bronk; Higham, T F G

2008-11-01

Accurate and precise dating is vital to our understanding of the Middle to Upper Paleolithic transition. There are, however, a number of uncertainties in the chronologies currently available for this period. We attempt to examine these uncertainties by utilizing a number of recent developments in the field. These include: the precise dating of the Campanian Ignimbrite (CI) tephra by 40Ar/39Ar; the tracing of this tephra to a number of deposits that are radiocarbon dated; the publication of revised radiocarbon calibration data for the period, showing a much better convergence with other available data than during the recent IntCal comparison; and a layer-counted ice-core chronology extending beyond 40,000cal BP. Our data comparisons suggest that a reasonable overall convergence between calibrated radiocarbon ages and calendar dates is possible using the new curves. Additionally, we suggest that charcoal-based radiocarbon ages, as well as bone-based radiocarbon determinations, require cautious interpretation in this period. Potentially, these issues extend far beyond the sites in this study and should be of serious concern to archaeologists studying the Middle to Upper Paleolithic. We conclude by outlining a strategy for moving the science forward by a closer integration of archaeology, chronology, and stratigraphy.

Aerodynamic Simulation Analysis of Unmanned Airborne Electronic Bomb

NASA Astrophysics Data System (ADS)

Yang, Jiaoying; Guo, Yachao

2017-10-01

For microelectronic bombs for UAVs, on the basis of the use of rotors to lift the insurance on the basis of ammunition, increased tail to increase stability. The aerodynamic simulation of the outer structure of the ammunition was carried out by FLUENT software. The resistance coefficient, the lift coefficient and the pitch moment coefficient under different angle of attack and Mach number were obtained, and the aerodynamic characteristics of the electronic bomb were studied. The pressure line diagram and the velocity line diagram of the flow around the bomb are further analyzed, and the rationality of the external structure is verified, which provides a reference for the subsequent design of the electronic bomb.

Game of thrown bombs in 3D: using high speed cameras and photogrammetry techniques to reconstruct bomb trajectories at Stromboli (Italy)

NASA Astrophysics Data System (ADS)

Gaudin, D.; Taddeucci, J.; Scarlato, P.; Del Bello, E.; Houghton, B. F.; Orr, T. R.; Andronico, D.; Kueppers, U.

2015-12-01

Large juvenile bombs and lithic clasts, produced and ejected during explosive volcanic eruptions, follow ballistic trajectories. Of particular interest are: 1) the determination of ejection velocity and launch angle, which give insights into shallow conduit conditions and geometry; 2) particle trajectories, with an eye on trajectory evolution caused by collisions between bombs, as well as the interaction between bombs and ash/gas plumes; and 3) the computation of the final emplacement of bomb-sized clasts, which is important for hazard assessment and risk management. Ground-based imagery from a single camera only allows the reconstruction of bomb trajectories in a plan perpendicular to the line of sight, which may lead to underestimation of bomb velocities and does not allow the directionality of the ejections to be studied. To overcome this limitation, we adapted photogrammetry techniques to reconstruct 3D bomb trajectories from two or three synchronized high-speed video cameras. In particular, we modified existing algorithms to consider the errors that may arise from the very high velocity of the particles and the impossibility of measuring tie points close to the scene. Our method was tested during two field campaigns at Stromboli. In 2014, two high-speed cameras with a 500 Hz frame rate and a ~2 cm resolution were set up ~350m from the crater, 10° apart and synchronized. The experiment was repeated with similar parameters in 2015, but using three high-speed cameras in order to significantly reduce uncertainties and allow their estimation. Trajectory analyses for tens of bombs at various times allowed for the identification of shifts in the mean directivity and dispersal angle of the jets during the explosions. These time evolutions are also visible on the permanent video-camera monitoring system, demonstrating the applicability of our method to all kinds of explosive volcanoes.

Impact on the Japanese atomic bomb survivors of radiation received from the bombs.

PubMed

Cullings, Harry M

2014-02-01

The Radiation Effects Research Foundation (RERF) studies various cohorts of Japanese atomic bomb survivors, the largest being the Life Span Study (LSS), which includes 93,741 persons who were in Hiroshima or Nagasaki at the times of the bombings; there are also cohorts of persons who were exposed in utero and survivors' children. This presentation attempts to summarize the total impact of the radiation from the bombs on the survivors from both an individual perspective (both age-specific and integrated lifetime risk, along with a measure of life expectancy that describes how the risk affects the individual given age at exposure) and a group perspective (estimated numbers of excess occurrences in the cohort), including both early and late effects. As survivors' doses ranged well into the acutely lethal range at closer distances, some of them experienced acute signs and symptoms of radiation exposure in addition to being at risk of late effects. Although cancer has always been a primary concern among late effects, estimated numbers of excess cancers and hematopoietic malignancies in the LSS are a small fraction of the total due to the highly skewed dose distribution, with most survivors receiving small doses. For example, in the latest report on cancer incidence, 853 of 17,448 incident solid cancers were estimated to be attributable to radiation from the bombs. RERF research indicates that risk of radiation-associated cancer varies among sites and that some benign tumors such as uterine myoma are also associated with radiation. Noncancer late effects appear to be in excess in proportion to radiation dose but with an excess relative risk about one-third that of solid cancer and a correspondingly small overall fraction of cases attributable to radiation. Specific risks were found for some subcategories, particularly circulatory disease, including stroke and precedent conditions such as hypertension. Radiation-related cataract in the atomic bomb survivors is well known

49 CFR 1544.303 - Bomb or air piracy threats.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Bomb or air piracy threats. 1544.303 Section 1544... AND COMMERCIAL OPERATORS Threat and Threat Response § 1544.303 Bomb or air piracy threats. (a) Flight.... (d) Notification. Upon receipt of any bomb threat against the security of a flight or facility, or...

49 CFR 1544.303 - Bomb or air piracy threats.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Bomb or air piracy threats. 1544.303 Section 1544... AND COMMERCIAL OPERATORS Threat and Threat Response § 1544.303 Bomb or air piracy threats. (a) Flight.... (d) Notification. Upon receipt of any bomb threat against the security of a flight or facility, or...

49 CFR 1544.303 - Bomb or air piracy threats.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Bomb or air piracy threats. 1544.303 Section 1544... AND COMMERCIAL OPERATORS Threat and Threat Response § 1544.303 Bomb or air piracy threats. (a) Flight.... (d) Notification. Upon receipt of any bomb threat against the security of a flight or facility, or...

49 CFR 1544.303 - Bomb or air piracy threats.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 9 2014-10-01 2014-10-01 false Bomb or air piracy threats. 1544.303 Section 1544... AND COMMERCIAL OPERATORS Threat and Threat Response § 1544.303 Bomb or air piracy threats. (a) Flight.... (d) Notification. Upon receipt of any bomb threat against the security of a flight or facility, or...

49 CFR 1544.303 - Bomb or air piracy threats.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 9 2013-10-01 2013-10-01 false Bomb or air piracy threats. 1544.303 Section 1544... AND COMMERCIAL OPERATORS Threat and Threat Response § 1544.303 Bomb or air piracy threats. (a) Flight.... (d) Notification. Upon receipt of any bomb threat against the security of a flight or facility, or...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fallon, S J; Guilderson, T P

To explore the seasonal to decadal variability in surface water masses that contribute to the Indonesian Throughflow we have generated a 115-year bi-monthly coral-based radiocarbon time-series from a coral in the Makassar Straits. In the pre-bomb (pre-1955) era from 1890 to 1954, the radiocarbon time series occasionally displays a small seasonal signal (10-15{per_thousand}). After 1954 the radiocarbon record increases rapidly, in response to the increased atmospheric {sup 14}C content caused by nuclear weapons testing. From 1957 to 1986 the record displays clear seasonal variability from 15 to 60{per_thousand} and the post-bomb peak (163 per mil) occurred in 1974. The seasonalmore » cycle of radiocarbon can be attributed to variations of surface waters passing through South Makassar Strait. Southern Makassar is under the influence of the Northwest Monsoon, which is responsible for the high Austral summer radiocarbon (North Pacific waters) and the Southeast Monsoon that flushes back a mixture of low (South Pacific and upwelling altered) radiocarbon water from the Banda Sea. The coral record also shows a significant {sup 14}C peak in 1955 due to bomb {sup 14}C water advected into this region in the form of CaCO{sub 3} particles (this implies that the particles were advected intact and then become entrapped in the coral skeleton--is this what we really mean? Wouldn't even fine particles settle out over the inferred transit time from Bikini to MAK?) or water particles with dissolved labeled CO{sub 2} produced during fallout from the Castle tests in 1954.« less

Low energy cyclotron for radiocarbon dating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Welch, J.J.

1984-12-01

The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer.more » These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.« less

Radiocarbon dating in archaeology: Interdisciplinary aspects and consequences (an overview)

NASA Astrophysics Data System (ADS)

Palincaş, Nona

2017-06-01

This paper is an overview of recent developments in the radiocarbon dating of the most frequently analyzed archaeological materials - wood, short-lived plants, and human and animal bones - and draws attention to two sets of consequences. Firstly, while radiocarbon dating has become more accessible to archaeologists thanks to an increase in the number of laboratories, a lowering of prices, and a reduction in sample sizes, it has also grown far more dependent on fields of research, other than the traditional chemical pretreatment of samples and the physics involved in their measurement, such as wood anatomy and other fields of botany, stable isotope-based diet studies, geochemistry, micromorphology, statistics, etc., most of which are not easily accessible by the vast majority of users of radiocarbon dating (and sometimes not familiar to practicing archaeologists). Secondly, given that, on the one hand, there is still much scope for research in radiocarbon dating and, on the other, archaeological sites are a limited resource, there is need to create archives containing the detailed documentation of samples and, whenever possible, sample residues.

A man, a plan, a bomb

NASA Astrophysics Data System (ADS)

Harris, Margaret

2015-03-01

Was the atomic bombing of Hiroshima and Nagasaki justified? Was it necessary? Were there other - better - options available, either to the scientists who built the bombs or the generals who ordered them dropped? Nearly 70 years later, there are still no settled answers to these questions, and Tom Morton-Smith's new play Oppenheimer wisely avoids dwelling on the "what ifs" of atomic history.

The 3.6 ka Aniakchak tephra in the Arctic Ocean: A constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea

USGS Publications Warehouse

Pearce, Christof; Varhelyi, Aron; Wastegård, Stefan; Muschitiello, Francesco; Barrientos Macho, Natalia; O'Regan, Matt; Cronin, Thomas M.; Gemery, Laura; Semiletov, Igor; Backman, Jan; Jakobsson, Martin

2017-01-01

The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenland. This large geographic distribution, combined with the fact that the eruption is relatively well constrained in time using radiocarbon dating of lake sediments and annual layer counts in ice cores, makes it an excellent stratigraphic marker for dating and correlating mid–late Holocene sediment and paleoclimate records. This study presents the outcome of a targeted search for the Aniakchak tephra in a marine sediment core from the Arctic Ocean, namely Core SWERUS-L2-2-PC1 (2PC), raised from 57 m water depth in Herald Canyon, western Chukchi Sea. High concentrations of tephra shards, with a geochemical signature matching that of Aniakchak ash, were observed across a more than 1.5 m long sediment sequence. Since the primary input of volcanic ash is through atmospheric transport, and assuming that bioturbation can account for mixing up to ca. 10 cm of the marine sediment deposited at the coring site, the broad signal is interpreted as sustained reworking at the sediment source input. The isochron is therefore placed at the base of the sudden increase in tephra concentrations rather than at the maximum concentration. This interpretation of major reworking is strengthened by analysis of grain size distribution which points to ice rafting as an important secondary transport mechanism of volcanic ash. Combined with radiocarbon dates on mollusks in the same sediment core, the volcanic marker is used to calculate a marine radiocarbon reservoir age offset ΔR = 477 ± 60 years. This relatively high value may be explained by the major influence of typically "carbon-old" Pacific waters, and it agrees well with recent estimates of ΔR along the northwest

An Investigation of Bomb Cyclogenesis in NCEP's CFS Model

NASA Astrophysics Data System (ADS)

Alvarez, F. M.; Eichler, T.; Gottschalck, J.

2008-12-01

With the concerns, impacts and consequences of climate change increasing, the need for climate models to simulate daily weather is very important. Given the improvements in resolution and physical parameterizations, climate models are becoming capable of resolving extreme weather events. A particular type of extreme event which has large impacts on transportation, industry and the general public is a rapidly intensifying cyclone referred to as a "bomb." In this study, bombs are investigated using the National Center for Environmental Prediction's (NCEP) Climate Forecast System (CFS) model. We generate storm tracks based on 6-hourly sea-level pressure (SLP) from long-term climate runs of the CFS model. Investigation of this dataset has revealed that the CFS model is capable of producing bombs. We show a case study of a bomb in the CFS model and demonstrate that it has characteristics similar to the observed. Since the CFS model is capable of producing bombs, future work will focus on trends in their frequency and intensity so that an assessment of the potential role of the bomb in climate change can be assessed.

Quality improvement program for the B83 bomb hand truck

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loll, M.B.; Buck, S.A.

1998-04-01

This report describes the problems, issues, and history of the H1347 bomb hand truck for the B83 bomb after the bomb was put into stockpile in the mid-1980s. Major issues that were reported in Unsatisfactory Reports (URs) were cracking problems on stacking fixture welds, cracked welds on the caster bracket receptacles on the cradle, cracked caster mounting brackets, casters unlocking from the swivel lock position, and caster tires rubbing and binding on the stacking frame. Resolution of these and other problems is described. The introduction of the H695B storage-only bomb hand truck to alleviate a shortage of bomb hand trucksmore » in the mid-1990s is described. The development and qualification of the H1347A bomb hand truck as a replacement for the H695 B is covered. The results from load test evaluations on the stacking fixture, cradle, and casters for the H1347 are described along with towing results on one and two-high stack configurations of B83 bombs in bomb hand trucks. New towing and truck/trailer transport procedures are described. Development, evaluation, and production recommendations for a stronger caster mounting bracket are described.« less

49 CFR 1546.301 - Bomb or air piracy threats.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Bomb or air piracy threats. 1546.301 Section 1546... Threat Response § 1546.301 Bomb or air piracy threats. No foreign air carrier may land or take off an airplane in the United States after receiving a bomb or air piracy threat against that airplane, unless the...

49 CFR 1546.301 - Bomb or air piracy threats.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Bomb or air piracy threats. 1546.301 Section 1546... Threat Response § 1546.301 Bomb or air piracy threats. No foreign air carrier may land or take off an airplane in the United States after receiving a bomb or air piracy threat against that airplane, unless the...

49 CFR 1546.301 - Bomb or air piracy threats.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 9 2014-10-01 2014-10-01 false Bomb or air piracy threats. 1546.301 Section 1546... Threat Response § 1546.301 Bomb or air piracy threats. No foreign air carrier may land or take off an airplane in the United States after receiving a bomb or air piracy threat against that airplane, unless the...

49 CFR 1546.301 - Bomb or air piracy threats.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 9 2013-10-01 2013-10-01 false Bomb or air piracy threats. 1546.301 Section 1546... Threat Response § 1546.301 Bomb or air piracy threats. No foreign air carrier may land or take off an airplane in the United States after receiving a bomb or air piracy threat against that airplane, unless the...

49 CFR 1546.301 - Bomb or air piracy threats.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Bomb or air piracy threats. 1546.301 Section 1546... Threat Response § 1546.301 Bomb or air piracy threats. No foreign air carrier may land or take off an airplane in the United States after receiving a bomb or air piracy threat against that airplane, unless the...

Review of Injuries from Terrorist Bombings and Earthquakes

DTIC Science & Technology

2016-08-31

distribution is unlimited. August 2016 Review of Injuries from Terrorist Bombings and Earthquakes DTRA-TR-16-064 T E C H N IC A L R E P...08-16 Technical Report 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Review of Injuries Types from Terrorist Bombings and Earthquakes HDTRA1-14-D-0003...Terrorist bombings and earthquakes provide valuable insight on the types of injuries that may occur in an improvised nuclear device (IND) scenario

The concept and science process skills analysis in bomb calorimeter experiment as a foundation for the development of virtual laboratory of bomb calorimeter

NASA Astrophysics Data System (ADS)

Kurniati, D. R.; Rohman, I.

2018-05-01

This study aims to analyze the concepts and science process skills in bomb calorimeter experiment as a basis for developing the virtual laboratory of bomb calorimeter. This study employed research and development method (R&D) to gain the answer to the proposed problems. This paper discussed the concepts and process skills analysis. The essential concepts and process skills associated with bomb calorimeter are analyze by optimizing the bomb calorimeter experiment. The concepts analysis found seven fundamental concepts to be concerned in developing the virtual laboratory that are internal energy, burning heat, perfect combustion, incomplete combustion, calorimeter constant, bomb calorimeter, and Black principle. Since the concept of bomb calorimeter, perfect and incomplete combustion created to figure out the real situation and contain controllable variables, in virtual the concepts displayed in the form of simulation. Meanwhile, the last four concepts presented in the form of animation because no variable found to be controlled. The process skills analysis detect four notable skills to be developed that are ability to observe, design experiment, interpretation, and communication skills.

The Worldwide Marine Radiocarbon Reservoir Effect: Definitions, Mechanisms, and Prospects

NASA Astrophysics Data System (ADS)

Alves, Eduardo Q.; Macario, Kita; Ascough, Philippa; Bronk Ramsey, Christopher

2018-03-01

When a carbon reservoir has a lower radiocarbon content than the atmosphere, this is referred to as a reservoir effect. This is expressed as an offset between the radiocarbon ages of samples from the two reservoirs at a single point in time. The marine reservoir effect (MRE) has been a major concern in the radiocarbon community, as it introduces an additional source of error that is often difficult to accurately quantify. For this reason, researchers are often reluctant to date marine material where they have another option. The influence of this phenomenon makes the study of the MRE important for a broad range of applications. The advent of Accelerator Mass Spectrometry (AMS) has reduced sample size requirements and increased measurement precision, in turn increasing the number of studies seeking to measure marine samples. These studies rely on overcoming the influence of the MRE on marine radiocarbon dates through the worldwide quantification of the local parameter ΔR, that is, the local variation from the global average MRE. Furthermore, the strong dependence on ocean dynamics makes the MRE a useful indicator for changes in oceanic circulation, carbon exchange between reservoirs, and the fate of atmospheric CO2, all of which impact Earth's climate. This article explores data from the Marine Reservoir Database and reviews the place of natural radiocarbon in oceanic records, focusing on key questions (e.g., changes in ocean dynamics) that have been answered by MRE studies and on their application to different subjects.

Astronautics and aeronautics, 1977: A chronology

NASA Technical Reports Server (NTRS)

Ritchie, E. H.

1986-01-01

This publication is a chronology of events during the year 1977 in the fields of aeronautical and space research, development, activity, and policy. It includes appendixes, an index, and illustrations. Chronological entries list sources for further inquiry.

Radiocarbon variability in the western equatorial Pacific inferred from a high-resolution coral record from Nauru Island

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guilderson, T.P.; Schrag, D.P.; Kashgarian, M.

1998-10-01

We have generated a high resolution coral {Delta}{sup 14}C record spanning the last 50 years to document the seasonal and interannual redistribution of surface waters in the western tropical Pacific. Prebomb (1947{endash}1956) {Delta}{sup 14}C values average {minus}63{per_thousand} and have a total range of 30{per_thousand}. Values begin to increase in 1957, reaching a maximum of 137{per_thousand} in mid-1983. Large interannual variability of up to 80{per_thousand} closely follows the El Ni{tilde n}o-Southern Oscillation (ENSO). During each ENSO warm phase, {Delta}{sup 14}C values begin to increase, reflecting the reduction of low-{sup 14}C water upwelling in the east and the invasion of subtropical watermore » into the western equatorial tropical Pacific. Maximum {Delta}{sup 14}C values are in phase or lag the corresponding sea surface temperature maxima in the eastern tropical Pacific, whereas the rapid return to more negative {Delta}{sup 14}C is in phase with eastern Pacific ENSO indices. The highest-amplitude excursions occur during the 1965/1966 and 1972/1973 events, when the {sup 14}C contrast is highest between the eastern Pacific and subtropics. The 1982/1983 El Ni{tilde n}o, although a larger ENSO event, has a lower {Delta}{sup 14}C amplitude, reflecting the penetration of bomb radiocarbon into the equatorial undercurrent and the reduced contrast in {Delta}{sup 14}C between thermocline and subtropical surface waters at that time. This coral record demonstrates the potential for using similar radiocarbon time series for documenting variability in Pacific shallow circulation over interannual and decadal timescales. {copyright} 1998 American Geophysical Union« less

Genomic instability in the epidermis induced by atomic bomb (A-bomb) radiation: a long-lasting health effect in A-bomb survivors.

PubMed

Naruke, Yuki; Nakashima, Masahiro; Suzuki, Keiji; Kondo, Hisayoshi; Hayashi, Tomayoshi; Soda, Midori; Sekine, Ichiro

2009-08-15

Radiation etiology is suggested in the occurrence of basal cell carcinoma (BCC) of the skin among atomic bomb (A-bomb) survivors. Any genotoxicity, including ionizing radiation, can induce a DNA damage response (DDR), leading to genomic instability (GIN), which allows the accumulation of mutations during tumorigenesis. In this study, the authors evaluated the presence of GIN in the epidermis of survivors as a late effect of A-bomb radiation. In total, 146 BCCs, including 23 cases arising from nonexposed skin, were identified in survivors from 1968 to 1999. The incidence rate (IR) of BCC was calculated with stratification by distance in kilometers from the hypocenter (< or =1.5 km, 1.6-2.9 km, and > or =3 km). Nineteen epidermal samples surrounding BCC at the nonexposed sites were collected and tested for p53 binding protein 1 (53BP1) expression with immunofluorescence. 53BP1 rapidly forms nuclear foci at the sites of DNA double strand breaks (DSBs). Because 1 manifestation of GIN is the induction of endogenous DSBs, the level of 53BP1-focus formation (DDR type) can be considered as a marker for GIN. : The incidence rate of BCC increased significantly as exposure distance approached the hypocenter. Of the 7 epidermal samples from the proximal group (< or =1.5 km), 5 samples predominantly expressed DDR and an abnormal type of 53BP1 expression. In contrast, 4 of 5 samples from the distal group (> or =3 km) and all samples from the control group predominantly expressed the stable type of 53BP1 expression in the epidermis. : The current results demonstrated the endogenous activation of DDR in the epidermis surrounding BCC in the proximal group, suggesting the presence of a GIN in the survivors as a late effect of A-bomb radiation, which may indicate a predisposition to cancer.

The secret of the Soviet hydrogen bomb

NASA Astrophysics Data System (ADS)

Wellerstein, Alex; Geist, Edward

2017-11-01

Was the first Soviet thermonuclear device really a step in the wrong direction? No bomb design has been as much maligned or otherwise disparaged as the first Soviet thermonuclear weapon. Detonated in August 1953, the bomb, officially tested under the name RDS-6s but usually known as Sloika or "layer cake" (the name Andrei Sakharov coined for it), was nothing to sneeze at. Shown in Figure 1 and able to be dropped from aircraft, it released the explosive equivalent, or yield, of almost half a megaton of TNT. The result was a blazing fireball with 20 times the power of the bomb that leveled Nagasaki, Japan.

Radiocarbon Records of Fossil Fuel Emissions From Urban Trees in the Greater Salt Lake Valley From Mid-Century to Present.

NASA Astrophysics Data System (ADS)

Chritz, K.; Buchert, M.; Walker, J. C.; Mendoza, D.; Pataki, D. E.; Xu, X.; Lin, J. C.

2017-12-01

Generating long term records of fossil fuel emissions of urban environments is complicated by the fact that direct observations of emissions and urban atmospheric CO2 concentrations were only collected in the recent past. Radiocarbon (14C) in tree rings from urban trees can provide archives of fossil fuel emissions that may track population growth over time, as higher population density is typically correlated with increased vehicular traffic and associated CO2 emissions, which are radiocarbon dead. We present radiocarbon measurements (n=125) from five roadside green ash trees (Fraxinus pennsylvanica) located in three cities of northern Utah - Salt Lake City (urban, 2016 population: 193,744), Logan City (agricultural, 2016 population: 49,110) and Heber (rural, 2016 population: 14,969). Urban trees were cored in four cardinal directions and ring widths were measured and counted to establish a chronology. One ring from every third year in a single core from each tree was removed and holocellulose was extracted from bulk wood of individual rings for 14C analysis. Fraction CO2 from fossil fuel burning (CO2-ff) was calculated using a simple mass-balance calculation from measured 14C values and remote background atmospheric 14CO2 values for NH Zone 2. The data from all three cities indicate a general trend of increasing CO2-ff uptake by the trees from 1980s to present, as expected with increased population growth and vehicular traffic. However, records in all three cities show unique elevated CO2-ff prior to the 1980s, assuming similar climate patterns through time, diverging from historic population size. We employed atmospheric simulations from the STILT (Stochastic Time-Inverted Lagrangian Transport) models for each of these trees to create footprints to determine source areas for CO2. These footprints reveal that atmospheric sampling areas can be large for certain trees, and other sources of 14C dead carbon, such as coal and natural gas from industrial emissions

Skylab: A chronology

NASA Technical Reports Server (NTRS)

Newkirk, R. W.; Ertel, I. D.; Brooks, C. G.

1977-01-01

The Skylab Program was specifically designed to conduct a series of experiments from beyond the earth's atmosphere. Since the number and types of experiments conducted during the operational phase of Skylab were constantly changing, rather than encumber the body of the chronology with these changes, a lengthy appendix on experiments is included in this document. This appendix identifies the principle investigators and coinvestigators; gives the types, numbers, and descriptions of the experiments; explains the purpose of the various experiments; and, where possible, gives the results or findings of the experiments. The body of the Skylab chronology is divided into three parts; early space station activities, Apollo applications, and Skylab development and operations.

Comparative AMS radiocarbon dating of pretreated versus non-pretreated tropical wood samples

NASA Astrophysics Data System (ADS)

Patrut, Adrian; von Reden, Karl F.; Lowy, Daniel A.; Mayne, Diana H.; Elder, Kathryn E.; Roberts, Mark L.; McNichol, Ann P.

2010-04-01

Several wood samples collected from Dorslandboom, a large iconic African baobab ( Adansonia digitata L.) from Namibia, were investigated by AMS radiocarbon dating subsequent to pretreatment and, alternatively, without pretreatment. The comparative statistical evaluation of results showed that there were no significant differences between fraction modern values and radiocarbon dates of the samples analyzed after pretreatment and without pretreatment, respectively. The radiocarbon date of the oldest sample was 993 ± 20 BP. Dating results also revealed that Dorslandboom is a multi-generation tree, with several stems showing different ages.

Long-term follow-up of atomic bomb survivors.

PubMed

Sakata, Ritsu; Grant, Eric J; Ozasa, Kotaro

2012-06-01

The Life Span Study (LSS) is a follow-up study of atomic bomb (A-bomb) survivors to investigate the radiation effects on human health and has collected data for over 60 years. The LSS cohort consists of 93,741 A-bomb survivors and another 26,580 age and sex-matched subjects who were not in either city at the time of the bombing. Radiation doses have been computed based on individual location and shielding status at the time of the bombings. Age at death and cause of death are gathered through the Japanese national family registry system and cancer incidence data have been collected through the Hiroshima and Nagasaki cancer registries. Noncancer disease incidence and health information are collected through biannual medical examinations among a subset of the LSS. Radiation significantly increases the risks of death (22% at 1 Gy), cancer incidence (47% at 1 Gy), death due to leukemia (310% at 1 Gy), as well as the incidence of several noncancer diseases (e.g. thyroid nodules, chronic liver disease and cirrhosis, uterine myoma, and hypertension). Significant effects on maturity (e.g. growth reduction and early menopause) were also observed. Long-term follow-up studies of the A-bomb survivors have provided reliable information on health risks for the survivors and form the basis for radiation protection standards for workers and the public. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Middle and Later Stone Age chronology of Kisese II rockshelter (UNESCO World Heritage Kondoa Rock-Art Sites), Tanzania

PubMed Central

Ranhorn, Kathryn L.; Kwekason, Amandus; Alex, Bridget; Laird, Myra F.; Marean, Curtis W.; Niespolo, Elizabeth; Nivens, Joelle; Mabulla, Audax Z. P.

2018-01-01

The archaeology of East Africa during the last ~65,000 years plays a central role in debates about the origins and dispersal of modern humans, Homo sapiens. Despite the historical importance of the region to these discussions, reliable chronologies for the nature, tempo, and timing of human behavioral changes seen among Middle Stone Age (MSA) and Later Stone Age (LSA) archaeological assemblages are sparse. The Kisese II rockshelter in the Kondoa region of Tanzania, originally excavated in 1956, preserves a ≥ 6-m-thick archaeological succession that spans the MSA/LSA transition, with lithic artifacts such as Levallois and bladelet cores and backed microliths, the recurrent use of red ochre, and >5,000 ostrich eggshell beads and bead fragments. Twenty-nine radiocarbon dates on ostrich eggshell carbonate make Kisese II one of the most robust chronological sequences for understanding archaeological change over the last ~47,000 years in East Africa. In particular, ostrich eggshell beads and backed microliths appear by 46–42 ka cal BP and occur throughout overlying Late Pleistocene and Holocene strata. Changes in lithic technology suggest an MSA/LSA transition that began 39–34.3 ka, with typical LSA technologies in place by the Last Glacial Maximum. The timing of these changes demonstrates the time-transgressive nature of behavioral innovations often linked to the origins of modern humans, even within a single region of Africa. PMID:29489827

Two approaches to timescale modeling for proxy series with chronological errors.

NASA Astrophysics Data System (ADS)

Divine, Dmitry; Godtliebsen, Fred

2010-05-01

A substantial part of proxy series used in paleoclimate research has chronological uncertainties. Any constructed timescale is therefore only an estimate of the true, but unknown timescale. An accurate assessment of the timing of events in the paleoproxy series and networks, as well as the use of proxy-based paleoclimate reconstructions in GCM model scoring experiments, requires the effect of these errors to be properly taken into account. We consider two types of the timescale error models corresponding to the two basic approaches to construction of the (depth-) age scale in a proxy series. Typically, a chronological control of a proxy series stemming from all types of marine and terrestrial sedimentary archives is based on the use of 14C dates, reference horizons or their combination. Depending on the prevalent origin of the available fix points (age markers) the following approaches to timescale modeling are proposed. 1) 14C dates. The algorithm uses Markov-chain Monte Carlo sampling technique to generate the ordered set of perturbed age markers. Proceeding sequentially from the youngest to the oldest fixpoint, the sampler draws random numbers from the age distribution of each individual 14C date. Every following perturbed age marker is generated such that condition of no age reversal is fulfilled. The relevant regression model is then applied to construct a simulated timescale. 2) Reference horizons (f. ex. volcanic or dust layers, T bomb peak) generally provide absolutely dated fixpoints. Due to a natural variability in sedimentation (accumulation) rate, however, the dating uncertainty in the interpolated timescale tends to grow together with a span to the nearest fixpoint. The (accumulation, sedimentation) process associated with formation of a proxy series is modelled using stochastic Levy process. The respective increments for the process are drawn from the log-normal distribution with the mean/variance ratio prescribed as a site(proxy)- dependent external

The Italians in America, 1492-1972: A Chronology and Fact Book. Ethnic Chronology Series, Number 4.

ERIC Educational Resources Information Center

LoGatto, Anthony F., Comp.

Contents of this chronology and fact book include the following: (i) Editor's foreword; (ii) Chronology; (iii) Twenty-one documents, ranging from "Charter granting Christopher Columbus the Prerogatives and Privileges of his Voyage--April 30, 1492," to "On the Care of Migrants," issued by Pope Paul VI on August 22, 1969; Nine appendices, including:…

33 CFR 334.520 - Lake George, Fla.; naval bombing area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Lake George, Fla.; naval bombing....; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as follows.... (2) Prior to each bombing operation the danger zone will be patrolled by naval aircraft which will...

33 CFR 334.520 - Lake George, Fla.; naval bombing area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Lake George, Fla.; naval bombing....; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as follows.... (2) Prior to each bombing operation the danger zone will be patrolled by naval aircraft which will...

Particle Detectors Subatomic Bomb Squad

ScienceCinema

Lincoln, Don

2018-01-16

The manner in which particle physicists investigate collisions in particle accelerators is a puzzling process. Using vaguely-defined “detectors,” scientists are able to somehow reconstruct the collisions and convert that information into physics measurements. In this video, Fermilab’s Dr. Don Lincoln sheds light on this mysterious technique. In a surprising analogy, he draws a parallel between experimental particle physics and bomb squad investigators and uses an explosive example to illustrate his points. Be sure to watch this video… it’s totally the bomb.

Population effects of the bombing of Oklahoma City.

PubMed

Smith, D W; Christiansen, E H; Vincent, R; Hann, N E

1999-04-01

The explosion at the Murrah Federal Building in Oklahoma City on April 19, 1995, affected many members of the community as well as direct victims. Our goal was to measure the exposure and effects among the general population. We conducted surveys of the Oklahoma City metropolitan area and a control area to measure exposure and impact, primarily stress and psychological distress. Of the adults in the Oklahoma City MSA, 61.5 percent (58.5 percent to 64.5 percent with 95 percent confidence) reported experiencing at least one direct result of the bombing. In population terms, about 433 thousand adults (between 412 thousand and 457 thousand, with 95 percent confidence) were exposed to one or more of the consequences of the bombing. Oklahomans reported higher rates (about double) of increased alcohol use, smoking more or starting smoking. They reported more stress (about double), psychological distress (about double), post-traumatic stress-disorder components, and intrusive thoughts (double) related to the bombing than in the control area. Oklahomans also reported higher rates of seeking help for their stress or taking steps to reduce stress. The differences persisted into 1996, more than a year after the bombing. The exposure to the bombing was widespread, including more than half the adults in the metropolitan area surrounding Oklahoma City. The psychological effects were high and, while decreasing, persisted more than a year after the bombing. Primary care practitioners should screen their patients, who may normally not be considered victims, for exposure to the effects of a terrorist disaster for an extended period of time.

Sticky bomb detection with other implications for vehicle security.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, R. G.; Vetrone, J.; Warner, J. S.

2010-01-01

A 'sticky bomb' is a type of improvised explosive device (IED) placed on a motor vehicle by (for example) a terrorist. The bomb is typically attached with adhesive ('duct') tape, or with magnets. This paper reports some preliminary results for a very rudimentary demonstration of two techniques for detecting the placement of a sticky bomb on a motor vehicle. The two techniques are tire pressure and magnetic measurements. There are other possible security applications for these techniques as well.

India: Chronology of Recent Events

DTIC Science & Technology

2007-02-13

Order Code RS21589 Updated February 13, 2007 India : Chronology of Recent Events K. Alan Kronstadt Specialist in Asian Affairs Foreign Affairs...Defense, and Trade Division Summary This report provides a reverse chronology of recent events involving India and India -U.S. relations. Sources include... India -U.S. Relations. This report will be updated regularly. 02/13/07 — Commerce Secretary Gutierrez began a two-day visit to New Delhi, where he

Radiocarbon application in environmental science and archaeology in Croatia

NASA Astrophysics Data System (ADS)

Krajcar Bronić, I.; Obelić, B.; Horvatinčić, N.; Barešić, J.; Sironić, A.; Minichreiter, K.

2010-07-01

Radiocarbon is a cosmogenic radioisotope equally distributed throughout the troposphere and biosphere. This fact enables its most common application—radiocarbon dating. Natural equilibrium of radiocarbon has been disturbed by diverse anthropogenic activities during the last ˜150 years, enabling also the use of 14C in various environmental applications. Here we present three types of studies by using 14C that were performed in the Zagreb Radiocarbon Laboratory. 14C in atmospheric CO 2 has been monitored at several sites with various anthropogenic influences and the difference between the clean-air sites, the industrial city and the vicinity of a nuclear power plant has been established. 14C has been applied in geochronology of karst areas, especially in dating of tufa, speleothems and lake sediments, as well as in studies of geochemical carbon cycle. 14C has been used in various archaeological studies, among which the dating of the early Neolithic settlements in Croatia is presented. In these studies 14C was measured by radiometric techniques, i.e., by gas proportional counting and more recently by liquid scintillation counting (LSC). Two sample preparation techniques for LSC measurement were used: benzene synthesis for archaeological dating and other applications that require better precision, and direct absorption of CO 2 for monitoring purposes. The presented results show that various studies by using 14C can be successfully performed by the LSC technique, providing a large enough sample (>1 g of carbon).

Annually resolved atmospheric radiocarbon records reconstructed from tree-rings

NASA Astrophysics Data System (ADS)

Wacker, Lukas; Bleicher, Niels; Büntgen, Ulf; Friedrich, Michael; Friedrich, Ronny; Diego Galván, Juan; Hajdas, Irka; Jull, Anthony John; Kromer, Bernd; Miyake, Fusa; Nievergelt, Daniel; Reinig, Frederick; Sookdeo, Adam; Synal, Hans-Arno; Tegel, Willy; Wesphal, Torsten

2017-04-01

The IntCal13 calibration curve is mainly based on data measured by decay counting with a resolution of 10 years. Thus high frequency changes like the 11-year solar cycles or cosmic ray events [1] are not visible, or at least not to their full extent. New accelerator mass spectrometry (AMS) systems today are capable of measuring at least as precisely as decay counters [2], with the advantage of using 1000 times less material. The low amount of material required enables more efficient sample preparation. Thus, an annually resolved re-measurement of the tree-ring based calibration curve can now be envisioned. We will demonstrate with several examples the multitude of benefits resulting from annually resolved radiocarbon records from tree-rings. They will not only allow for more precise radiocarbon dating but also contain valuable new astrophysical information. The examples shown will additionally indicate that it can be critical to compare AMS measurements with a calibration curve that is mainly based on decay counting. We often see small offsets between the two measurement techniques, while the reason is yet unknown. [1] Miyake F, Nagaya K, Masuda K, Nakamura T. 2012. A signature of cosmic-ray increase in AD 774-775 from tree rings in Japan. Nature 486(7402):240-2. [2] Wacker L, Bonani G, Friedrich M, Hajdas I, Kromer B, Nemec M, Ruff M, Suter M, Synal H-A, Vockenhuber C. 2010. MICADAS: Routine and high-precision radiocarbon dating. Radiocarbon 52(2):252-62.

Correlating Ice Cores from Quelccaya Ice Cap with Chronology from Little Ice Age Glacial Extents

NASA Astrophysics Data System (ADS)

Stroup, J. S.; Kelly, M. A.; Lowell, T. V.

2010-12-01

Proxy records indicate Southern Hemisphere climatic changes during the Little Ice Age (LIA; ~1300-1850 AD). In particular, records of change in and around the tropical latitudes require attention because these areas are sensitive to climatic change and record the dynamic interplay between hemispheres (Oerlemans, 2005). Despite this significance, relatively few records exist for the southern tropics. Here we present a reconstruction of glacial fluctuations of Quelccaya Ice Cap (QIC), Peruvian Andes, from pre-LIA up to the present day. In the Qori Kalis valley, extensive sets of moraines exist beginning with the 1963 AD ice margin (Thompson et al., 2006) and getting progressively older down valley. Several of these older moraines can be traced and are continuous with moraines in the Challpa Cocha valley. These moraines have been dated at <1050-1350-AD (Mercer and Palacios, 1977) and interpreted to have been deposited during the Little Ice Age. We present a new suite of surface exposure and radiocarbon dates collected in 2008 and 2009 that constrain the ages of these moraines. Preliminary 10Be ages of boulder surfaces atop the moraines range from ~350-1370 AD. Maximum and minimum-limiting radiocarbon ages bracketing the moraines are ~0-1800 AD. The chronology of past ice cap extents are correlated with ice core records from QIC which show an accumulation increase during ~1500-1700 AD and an accumulation decrease during ~1720-1860 AD (Thompson et al., 1985; 1986; 2006). In addition, other proxy records from Peru and the tropics are correlated with the records at QIC as a means to understand climate conditions during the LIA. This work forms the basis for future modeling of the glacial system during the LIA at QIC and for modeling of past temperature and precipitation regimes at high altitude in the tropics.

Cardiovascular disease among atomic bomb survivors.

PubMed

Ozasa, Kotaro; Takahashi, Ikuno; Grant, Eric J; Kodama, Kazunori

2017-10-01

The profile of cardiovascular disease in Japan has been different from that in Western countries. Hypertension was the major cause not only for hemorrhagic stroke but also for ischemic stroke and heart disease in the past, and the influence of hypertension has decreased with calendar years because of reduced salt intake and westernization of lifestyle, and also improved medical care. The health status of atomic bomb survivors has reflected this profile as well as radiation effects. It is also likely that this cohort has been affected by the difficult conditions experienced in the aftermath of the war and atomic bombings. In this article, we tried to make a consistent interpretation of epidemiological findings of atomic bomb radiation effects on cardiovascular disease. Among the atomic bomb survivors, radiation exposure was associated with some cardiovascular diseases that are often associated with hypertension, and dose response appeared to be primarily non-linear among those who were exposed at younger ages. These effects are thought to reflect the nature of whole body irradiation. But, some findings remain inconsistent, possibly because of possible misclassification in death certificate diagnoses in the Life Span Study as well as selected information from the Adult Health Study which was limited to participants, focused on specific outcomes, and gathered in selected periods of follow-up. Therefore, a comprehensive and balanced interpretation of the results from both groups is necessary.

Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia.

PubMed

Sutikna, Thomas; Tocheri, Matthew W; Morwood, Michael J; Saptomo, E Wahyu; Jatmiko; Awe, Rokus Due; Wasisto, Sri; Westaway, Kira E; Aubert, Maxime; Li, Bo; Zhao, Jian-xin; Storey, Michael; Alloway, Brent V; Morley, Mike W; Meijer, Hanneke J M; van den Bergh, Gerrit D; Grün, Rainer; Dosseto, Anthony; Brumm, Adam; Jungers, William L; Roberts, Richard G

2016-04-21

Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.

New bomb, no mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mello, G.

1997-05-01

The cold war may be over, but the nuclear arms race has not quite ended. The United States is fielding a new nuclear weapon-a bomb that was used to threaten Libya, a non-nuclear nation, even before it was deployed. The B61 {open_quotes}mod-11{close_quotes} gravity bomb is the first nuclear capability added to the US arsenal since 1989. It was developed and deployed secretly, without public or congressional debate, and in apparent contradiction to official domestic and international assurances that no new nuclear weapons were being developed in the United States. The B61-11`s unique earth-penetrating characteristic and wide range of yields allowmore » it to threaten otherwide indestructible targets from the air-or, in Pentagonese, to hold such targets {open_quotes}at risk.{close_quotes} That makes the B61-11 a uniquely useful warfighting tool. The 1,200-pound B61-11 replaces the B53, a 8,900-pound, nine-megaton bomb that was developed as a {open_quotes}city buster{close_quotes} and was later designated as a substitute for an earth-penetrating weapon. The B53 was deliverable only by vulnerable B-52s; in contrast, the smaller and lighter B61-11 can be delivered the the stealthier B-2A bomber, or even by F16 fighters.« less

Simultaneous observations of Ellerman bombs by NST and IRIS

NASA Astrophysics Data System (ADS)

Kim, Y. H.; Yurchyshyn, V.; Cho, I. H.; Lee, J.; Park, Y. D.; Yang, H.; Ahn, K.; Goode, P.

2015-12-01

In this study, we present the simultaneous observations of Ellerman bombs made by New Solar Telescope (NST) of Big Bear Solar Observatory (BBSO) and Interface Region Imaging Spectrograph (IRIS) in space. The data obtained during joint NST-IRIS observations on 30 and 31 in July 2014. We observed two representative events on both days. The first one was a relatively weak Ellerman bomb occurred around 19:20 UT on 30 July 2014. IRIS observed this event by sit-and-stare mode thus we analyzed high cadence spectral data and slit-jaw data simultaneously. We found that this event was a hot explosion that occurred by magnetic reconnection in the lower atmosphere of the Sun. The second event was quite strong Ellerman bomb (20:20 UT on 31 July 2014) that is well observed by NST FISS (Fast Imaging Solar Spectrograph), while there was no IRIS spectral data. We had IRIS slit-jaw data only. The Ellerman bomb was clearly coincident with the IRIS brightening at the same location. Since the Ellerman bombs are usually believed to occur in the photosphere with no coronal emission, it should be explained its higher atmospheric emission in IRIS data. We will present the result of simultaneous observations by IRIS and NST instruments and discuss physical connection between Ellerman bombs and IRIS brightenings.

Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life.

PubMed

Lynnerup, Niels; Kjeldsen, Henrik; Heegaard, Steffen; Jacobsen, Christina; Heinemeier, Jan

2008-01-30

Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule) completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14)C content from the atmospheric carbon dioxide. The (14)C content of the lens proteins thus reflects the atmospheric content of (14)C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the (14)C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric (14)C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the (14)C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA). Potential targets may be nervous tissues in terms of senile or pre-senile degradation, as well as other highly specialised structures of the eyes. The precision with

Late Quaternary lake-level changes constrained by radiocarbon and stable isotope studies on sediment cores from Lake Titicaca, South America

NASA Astrophysics Data System (ADS)

Rowe, Harold D.; Guilderson, Thomas P.; Dunbar, Robert B.; Southon, John R.; Seltzer, Geoffrey O.; Mucciarone, David A.; Fritz, Sherilyn C.; Baker, Paul A.

2003-09-01

We present and compare AMS- 14C geochronologies for sediment cores recovered from Lake Titicaca, South America. Radiocarbon dates from three core sites constrain the timing of late Quaternary paleoenvironmental changes in the Central Andes and highlight the site-specific factors that limit the radiocarbon geochronometer. With the exception of mid-Holocene sediments, all cores are generally devoid of macrophyte fragments, thus bulk organic fractions are used to build core chronologies. Comparisons of radiocarbon results for chemically defined fractions (bulk decalcified, humate, humin) suggest that ages derived from all fractions are generally coherent in the post-13,500 yr BP time interval. In the pre-13,500 yr BP time interval, ages derived from humate extracts are significantly younger (300-7000 years) than ages from paired humin residues. Gross age incoherencies between paired humate and humin sub-fractions in pre-13,500 yr BP sediments from all core sites probably reflect the net downward migration of humates. Ages derived from bulk decalcified fractions at our shallow water (90 m) and deep water (230 m) core sites consistently fall between ages derived from humate and humin sub-fractions in the pre-13,500 yr BP interval, reflecting that the bulk decalcified fraction is predominantly a mixture of humate and humin sub-fractions. Bulk decalcified ages from the pre-13,500 yr BP interval at our intermediate depth core site (150 m) are consistently older than humate (youngest) and humin sub-fractions. This uniform, reproducible pattern can be explained by the mobilization of a relatively older organic sub-fraction during and after the re-acidification step following the alkaline treatment of the bulk sediment. The inferred existence of this 'alkali-mobile, acid-soluble' sub-fraction implies a different depositional/post-depositional history that is potentially associated with a difference in source material. While internally consistent geochronologies can be

Astronautics and Aeronautics, 1986-1990: A Chronology

NASA Technical Reports Server (NTRS)

Gawdiak, Ihor Y.; Miro, Ramon J.; Stueland, Sam

1997-01-01

This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the LibrarY of Congress for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1996-1990 and continues the series of annual chronologies published by NASA. The present volume returns to the format used in the Astronautics and Aeronautics, 1979-1984: A Chronology volume. It also integrates in a single table the information presented in two or three previous publications.

Astronautics and Aeronautics, 1991-1995: A Chronology

NASA Technical Reports Server (NTRS)

Gawdiak, Ihor Y. (Compiler); Shetland, Charles (Compiler)

2000-01-01

This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the Library of Congress and RSIS for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1991-1995 and continues the series of annual chronologies published by NASA. The present volume uses the format of the previous edition of this series, Astronautics and Aeronautics, 1986-1990: A Chronology. It also integrates, in the appendices, information presented in previous publication

Youngest radiocarbon age for Jefferson's ground sloth, Megalonyx jeffersonii (Xenarthra, Megalonychidae)

NASA Astrophysics Data System (ADS)

Gregory McDonald, H.; Stafford, Thomas W.; Gnidovec, Dale M.

2015-03-01

A partial skeleton of the extinct ground sloth, Megalonyx jeffersonii, recovered from a farm near Millersburg, Ohio in 1890, was radiocarbon dated for the first time. The ungual dated is part of a skeleton mounted for exhibit at the Orton Geological Museum at Ohio State University and was the first mounted skeleton of this animal. From its initial discovery the bones were treated with multiple organic compounds that had the potential to compromise the radiocarbon age and the specimen required special treatments in order to obtain a valid radiocarbon age. The 14C measurement on the ungual from this skeleton (11,235 ± 40 14C yr BP = 13,180-13,034 cal yr BP) is the youngest 14C age presently determined for M. jeffersonii.

Factors associated with injury severity in Oklahoma City bombing survivors.

PubMed

Glenshaw, Mary T; Vernick, Jon S; Li, Guohua; Sorock, Gary S; Brown, Sheryll; Mallonee, Sue

2009-02-01

Terrorist bombings are an increasing source of violent death and injury worldwide. Injuries in building bombings have been previously reported in descriptive studies, but no comparative analyses have quantitatively assessed factors influencing the severity of nonfatal bombing injuries. The objective of this study was to identify personal and environmental risk factors for injury severity in the Oklahoma City bombing, on April 19, 1995. We conducted a retrospective comparative analysis of 509 nonfatally injured occupants of four buildings surrounding the detonation site. The source of data was the 1995 Oklahoma City Bombing database, a registry of all injuries and fatalities related to the bombing. Multivariable logistic regression was used to assess two outcomes: (1) medically-attended injury among injured occupants; and (2) hospital admission among occupants with medically attended injuries. Increased odds of sustaining medically attended injuries were associated with being struck by flying glass (adjusted odds ratio [AOR], 5.3; 95% confidence interval [CI], 1.9-14.8) and location above the first floor of buildings (OR, 4.0; 95% CI, 1.4-11.7) after adjustment for other factors. Adjusted odds of hospital admission were associated with location in the collapsed region (AOR, 43.4; 95% CI, 4.4-434.1), being blown by the blast wind (AOR, 5.3; 95% CI, 2.1-13.8), and being trapped (AOR, 3.1; 95% CI, 1.2-7.7). The severity of nonfatal injury in the Oklahoma bombing was primarily associated with structural and environmental factors. Improved architectural design may prevent many injuries in building bombings. These finding provide evidence for future injury prevention activities.

Algebraically special resonances of the Kerr-black-hole-mirror bomb

NASA Astrophysics Data System (ADS)

Hod, Shahar

2013-12-01

A corotating bosonic field interacting with a spinning Kerr black hole can extract rotational energy and angular momentum from the hole. This intriguing phenomenon is known as superradiant scattering. As pointed out by Press and Teukolsky, the black-hole-field system can be made unstable (explosive) by placing a reflecting mirror around the black hole, which prevents the extracted energy from escaping to infinity. This composed black-hole-mirror-field bomb has been studied extensively by many researchers. It is worth noting, however, that most former studies of the black-hole bomb phenomenon have focused on the specific case of confined scalar (spin-0) fields. In the present study we explore the physical properties of the higher-spin (electromagnetic and gravitational) black-hole bombs. It is shown that this composed system is amenable to an analytic treatment in the physically interesting regime of rapidly rotating black holes. In particular, we prove that the composed black-hole-mirror-field bomb is characterized by the unstable resonance frequency ω=mΩH+is·2πTBH (here s and m are, respectively, the spin parameter and the azimuthal harmonic index of the field, and ΩH and TBH are, respectively, the angular-velocity and the temperature of the rapidly spinning black hole). Our results provide evidence that the higher-spin (electromagnetic and gravitational) black-hole-mirror bombs are much more explosive than the extensively studied scalar black-hole-mirror bomb. In particular, it is shown here that the instability growth rates that characterize the higher-spin black-hole bombs are 2 orders of magnitude larger than the instability growth rate of the scalar black-hole bomb.

Imaginary Savior: the image of the nuclear bomb in Korea, 1945-1960.

PubMed

Kim, Dong-Won

2009-01-01

Two atomic bombs dropped on Hiroshima and Nagasaki in August 1945 brought the unexpected liberation of Korea from the 35-year Japanese occupation. Koreans therefore had a very favorable and positive image of the nuclear bomb and nuclear energy from the beginning. The image of the nuclear bomb as "savior" was strengthened during the Korean War when the United States openly mentioned the possible use of the nuclear bomb against North Korean and Chinese military. After the end of the Korean War in July 1953 South Koreans strongly supported the development of the nuclear bomb in order to deter another North Korean invasion. When the US government provided South Korea with a research nuclear reactor in the late 1950s, most South Koreans hailed it as the first step to developing their own nuclear bomb. This paper will analyze how and why the savior image of the nuclear bomb originated and spread in Korea during the 1950s.

A combined method for DNA analysis and radiocarbon dating from a single sample.

PubMed

Korlević, Petra; Talamo, Sahra; Meyer, Matthias

2018-03-07

Current protocols for ancient DNA and radiocarbon analysis of ancient bones and teeth call for multiple destructive samplings of a given specimen, thereby increasing the extent of undesirable damage to precious archaeological material. Here we present a method that makes it possible to obtain both ancient DNA sequences and radiocarbon dates from the same sample material. This is achieved by releasing DNA from the bone matrix through incubation with either EDTA or phosphate buffer prior to complete demineralization and collagen extraction utilizing the acid-base-acid-gelatinization and ultrafiltration procedure established in most radiocarbon dating laboratories. Using a set of 12 bones of different ages and preservation conditions we demonstrate that on average 89% of the DNA can be released from sample powder with minimal, or 38% without any, detectable collagen loss. We also detect no skews in radiocarbon dates compared to untreated samples. Given the different material demands for radiocarbon dating (500 mg of bone/dentine) and DNA analysis (10-100 mg), combined DNA and collagen extraction not only streamlines the sampling process but also drastically increases the amount of DNA that can be recovered from limited sample material.

Ultrasonic Device Would Open Pipe Bombs

NASA Technical Reports Server (NTRS)

El-Raheb, Michael S.; Adams, Marc A.; Zwissler, James G.

1991-01-01

Piezoelectric ultrasonic transducer, energized by frequency generator and power supply, vibrates shell of pipe bomb while hardly disturbing explosive inner material. Frequency-control circuitry senses resonance in shell and holds generator at that frequency to induce fatigue cracking in threads of end cap. In addition to disarming bombs, ultrasonically induced fatigue may have other applications. In manufacturing, replaces some machining and cutting operations. In repair of equipment, cleanly and quickly disassembles corroded parts. In demolition of buildings used to dismember steel framework safely and controllably.

Biogenic contribution to PM-2.5 ambient aerosol from radiocarbon measurements

NASA Astrophysics Data System (ADS)

Lewis, C.; Klouda, G.; Ellenson, W.

2003-04-01

Knowledge of the relative contributions of biogenic versus anthropogenic sources to ambient aerosol is of great interest in the formulation of strategies to achieve nationally mandated air quality standards. Radiocarbon (14C) measurements provide a means to quantify the biogenic fraction of any carbon-containing sample of ambient aerosol. In the absence of an impact from biomass burning (e.g., during summertime) such measurements can provide an estimate of the contribution of biogenic secondary organic aerosol, from biogenic volatile organic compound precursors. Radiocarbon results for 11.5-h PM-2.5 samples collected near Nashville, Tennessee, USA, during summer 1999 will be presented. On average the measured biogenic fraction was surprisingly large (more than half), with the average biogenic fraction for night samples being only slightly smaller than for day samples. Discussion will include (a) description of the radiocarbon methodology, (b) use of radiocarbon measurements on local vegetation and fuel samples as calibration data, (c) concurrent measurements of organic carbon and elemental carbon ambient concentrations, (d) assessment of organic aerosol sampling artifact through use of organic vapor denuders, variable face velocities, and filter extraction, and (e) comparison with published radiocarbon results obtained in Houston, Texas in a similar study. Disclaimer: This work has been funded wholly or in part by the United States Environmental Protection Agency under Interagency Agreement No. 13937923 to the National Institute of Standards and Technology, and Contract No. 68-D5-0049 to ManTech Environmental Tecnology, Inc. It has been subjected to Agency review and approved for publication.

The role of radiology in the Oklahoma City bombing.

PubMed

Nye, P J; Tytle, T L; Jarman, R N; Eaton, B G

1996-08-01

To evaluate the role of radiologic services in the assessment of injuries and identification of deceased victims of the bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Okla. In cooperation with the Oklahoma University Health Sciences Center Disaster Studies Group, all victims of the Oklahoma City bombing who were treated in hospitals were evaluated. All radiologic studies performed in these patients during a 4-week period after the bombing were recorded. Major injuries incurred by the victims were noted but were not documented. In addition, assistance provided by radiologic services to the medical examiner's office for identification of deceased victims was assessed. On the day of the bombing, 99% (480 of 485) of the imaging studies performed were either plain radiography, primarily of the extremities and chest, or computed tomography (CT), half of which were of the head. Six deceased victims were identified solely by means of characteristics on radiographs. Almost all bombing-related radiologic studies were either plain radiography or CT. Other modalities had only limited roles. In deceased victims, plain radiography aided identification, and in many other victims it allowed localization of materials that were potential pieces of evidence.

Direct radiocarbon dating and genetic analyses on the purported Neanderthal mandible from the Monti Lessini (Italy).

PubMed

Talamo, Sahra; Hajdinjak, Mateja; Mannino, Marcello A; Fasani, Leone; Welker, Frido; Martini, Fabio; Romagnoli, Francesca; Zorzin, Roberto; Meyer, Matthias; Hublin, Jean-Jacques

2016-07-08

Anatomically modern humans replaced Neanderthals in Europe around 40,000 years ago. The demise of the Neanderthals and the nature of the possible relationship with anatomically modern humans has captured our imagination and stimulated research for more than a century now. Recent chronological studies suggest a possible overlap between Neanderthals and anatomically modern humans of more than 5,000 years. Analyses of ancient genome sequences from both groups have shown that they interbred multiple times, including in Europe. A potential place of interbreeding is the notable Palaeolithic site of Riparo Mezzena in Northern Italy. In order to improve our understanding of prehistoric occupation at Mezzena, we analysed the human mandible and several cranial fragments from the site using radiocarbon dating, ancient DNA, ZooMS and isotope analyses. We also performed a more detailed investigation of the lithic assemblage of layer I. Surprisingly we found that the Riparo Mezzena mandible is not from a Neanderthal but belonged to an anatomically modern human. Furthermore, we found no evidence for the presence of Neanderthal remains among 11 of the 13 cranial and post-cranial fragments re-investigated in this study.

Direct radiocarbon dating and genetic analyses on the purported Neanderthal mandible from the Monti Lessini (Italy)

PubMed Central

Talamo, Sahra; Hajdinjak, Mateja; Mannino, Marcello A.; Fasani, Leone; Welker, Frido; Martini, Fabio; Romagnoli, Francesca; Zorzin, Roberto; Meyer, Matthias; Hublin, Jean-Jacques

2016-01-01

Anatomically modern humans replaced Neanderthals in Europe around 40,000 years ago. The demise of the Neanderthals and the nature of the possible relationship with anatomically modern humans has captured our imagination and stimulated research for more than a century now. Recent chronological studies suggest a possible overlap between Neanderthals and anatomically modern humans of more than 5,000 years. Analyses of ancient genome sequences from both groups have shown that they interbred multiple times, including in Europe. A potential place of interbreeding is the notable Palaeolithic site of Riparo Mezzena in Northern Italy. In order to improve our understanding of prehistoric occupation at Mezzena, we analysed the human mandible and several cranial fragments from the site using radiocarbon dating, ancient DNA, ZooMS and isotope analyses. We also performed a more detailed investigation of the lithic assemblage of layer I. Surprisingly we found that the Riparo Mezzena mandible is not from a Neanderthal but belonged to an anatomically modern human. Furthermore, we found no evidence for the presence of Neanderthal remains among 11 of the 13 cranial and post-cranial fragments re-investigated in this study. PMID:27389305

Relative chronology of Martian volcanoes

NASA Technical Reports Server (NTRS)

Landheim, R.; Barlow, N. G.

1991-01-01

Impact cratering is one of the major geological processes that has affected the Martian surface throughout the planet's history. The frequency of craters within particular size ranges provides information about the formation ages and obliterative episodes of Martian geologic units. The Barlow chronology was extended by measuring small craters on the volcanoes and a number of standard terrain units. Inclusions of smaller craters in units previously analyzed by Barlow allowed for a more direct comparison between the size-frequency distribution data for volcanoes and established chronology. During this study, 11,486 craters were mapped and identified in the 1.5 to 8 km diameter range in selected regions of Mars. The results are summarized in this three page report and give a more precise estimate of the relative chronology of the Martian volcanoes. Also, the results of this study lend further support to the increasing evidence that volcanism has been a dominant geologic force throughout Martian history.

The Freezing Bomb

ERIC Educational Resources Information Center

Mills, Allan

2010-01-01

The extreme pressures that are generated when water freezes were traditionally demonstrated by sealing a small volume in a massive cast iron "bomb" and then surrounding it with a freezing mixture of ice and salt. This vessel would dramatically fail by brittle fracture, but no quantitative measurement of bursting pressure was available. Calculation…

Environmental Composites for Bomb Cyclones of the Western North Atlantic in Reanalysis, 1948-2016.

NASA Astrophysics Data System (ADS)

Adams, R.; Sheridan, S. C.

2017-12-01

"Bomb" cyclones represent a small subset of mid-latitude cyclones characterized by rapid intensification and frequently are associated with extreme weather conditions along the eastern coast of North America. Like other extreme phenomena, bomb cyclone predictions are prone to error leading to inadequate or untimely hazard warnings. The rare nature of bomb cyclones and the uniqueness of their evolutions has made it difficult for researchers to make meaningful generalizations on bomb cyclone events. This paper describes bomb cyclone climatology for the western North Atlantic, using data from the NCEP-NCAR Reanalysis for 1948-2016, and uses a synoptic climatological analysis to relate these bombs to their associated atmospheric environments. A self-organizing map (SOM) of 300-hPa geopotential height tendency is created to partition the regional atmospheric environment. Thermodynamic fields are contrasted by each 300-hPa geopotential height tendency pattern for both bomb and non-bomb events in composite difference maps. The SOM patterns most significantly associated with western North Atlantic bomb cyclogenesis are characterized by both strongly and weakly negative height tendencies along the eastern United States. In both cases, these patterns exhibit strong meridional flow, a distinction marked by the weakening and breaking down of the polar vortex in the boreal Winter. The composite maps for each pattern show the mean differences in low-mid level ascent and near surface thermodynamics for bomb environments contrasted with non-bomb environments, resulting in diverse spatiotemporal distributions of bombs in the western North Atlantic.

Uganda: Perfection of Post-Conflict Stability or Ticking Time Bomb

DTIC Science & Technology

2016-01-01

1 UGANDA: PERFECTION OF POST-CONFLICT STABILITY OR TICKING TIME BOMB ? By Kristin M. Pearson and Alex S. Pedersen, United States Air...Force Academy 2015 INSS RESEARCH PAPER 2016 2 UGANDA: PERFECTION OF POST-CONFLICT STABILITY OR TICKING TIME BOMB ? By Kristin M. Pearson and Alex...likely. “The area is a ticking time bomb without ongoing efforts. There’s an entire group of young men trained in military tactics that have said

The bomb 14C transient in the Pacific Ocean

NASA Astrophysics Data System (ADS)

Rodgers, Keith B.; Schrag, Daniel P.; Cane, Mark A.; Naik, Naomi H.

2000-04-01

A modeling study of the bomb 14C transient is presented for the Pacific Ocean. A primitive equation ocean circulation model has been configured for a high-resolution domain that accounts for the Indonesian Throughflow (ITF). Four separate runs were performed: (1) seasonal forcing with 20 Sv of ITF transport, (2) seasonal forcing with 10 Sv of ITF transport, (3) seasonal forcing with no ITF transport, and (4) interannual forcing with 15 Sv of ITF transport. This study has two main objectives. First, it is intended to describe the time evolution of the bomb 14C transient. This serves as a tool with which one can identify the physical processes controlling the evolving bomb 14C distribution in the Pacific thermocline and thus provides an interpretive framework for the database of Δ14C measurements in the Pacific. Second, transient tracers are applied to the physical oceanographic problem of intergyre exchange. This is of importance in furthering our understanding of the potential role of the upper Pacific Ocean in climate variability. We use bomb 14C as a dye tracer of intergyre exchange between the subtropical gyres and the equatorial upwelling regions of the equatorial Pacific. Observations show that while the atmospheric Δ14C signal peaked in the early to mid-1960s, the Δ14C levels in the surface water waters of the subtropical gyres peaked near 1970, and the Δ14C of surface waters in the equatorial Pacific continued to rise through the 1980s. It is shown that the model exhibits skill in representing the large-scale observed features observed for the bomb 14C transient in the Pacific Ocean. The model successfully captures the basin-scale inventories of bomb 14C in the tropics as well as in the extratropics of the North Pacific. For the equatorial Pacific this is attributed to the model's high meridional resolution. The discrepancies in the three-dimensional distribution of bomb 14C between the model and data are discussed within the context of the dynamical

Did Divorces Decline after the Oklahoma City Bombing?

ERIC Educational Resources Information Center

Nakonezny, Paul A.; Reddick, Rebecca; Rodgers, Joseph Lee

2004-01-01

The Oklahoma City bombing in April 1995 was an act of terrorism that had many potential influences on the city and state, including influences on families. We analyzed divorce data from 1985 to 2000 for all 77 counties in Oklahoma to assess the divorce response to the Oklahoma City bombing. Our prediction was that divorce rates in Oklahoma would…

Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

USGS Publications Warehouse

Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

2010-01-01

We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was −254‰ in agricultural drains in the Sacramento–San Joaquin Delta, −218‰ in the San Joaquin River, −175‰ in the California State Water Project and −152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California’s Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, −204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between −275 and −687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California’s Central Valley.

Is Einstein the Father of the Atomic Bomb

NASA Astrophysics Data System (ADS)

Lustig, Harry

2009-05-01

Soon after the American atomic bombs were dropped on Hiroshima and Nagasaki, the notion took hold in the popular mind that Albert Einstein was ``the father of the bomb.'' The claim of paternity rests on the belief that E=mc2 is what makes the release of enormous amounts of energy in the fission process possible and that the atomic bomb could not have been built without it. This is a misapprehension. Most physicists have known that all along. Nevertheless in his reaction to the opera Dr. Atomic, a prominent physicist claimed that Einstein's discovery that matter can be transformed into energy ``is precisely what made the bomb possible.'' In fact what makes the fission reaction and one of its applications,the atomic bomb, possible is the smaller binding energies of fission products compared to the binding energies of the nuclei that undergo fission.The binding energies of nuclei are a well understood consequence of the numbers and arrangements of protons and neutrons in the nucleus and of quantum-mechanical effects. The realization that composite systems have binding energies predates relativity. In the 19th century they were ascribed to potential and other forms of energy that reside in the system. With Einstein they became rest mass energy. While E=mc2 is not the cause of fission, measuring the masses of the participants in the reaction does permit an easy calculation of the kinetic energy that is released.

Slow fuze on the neutron bomb

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frye, A.

The U.S. government has wrestled with the neutron bomb's production and its potential bargaining powers for years. President Carter's decision not to decide about the neutron bomb has now provoked a furor. The alarm focuses more on the politics of the decision than on its moral, military, and strategic aspects. The political reaction to Carter's deferring production may virtually compel him to produce neutron warheads eventually, unless the Soviet Union displays compensating restraint in the coming months. While the Kremlin has indicated a willingness to forgo production of similar weapons of its own, it is unlikely to accept American demandsmore » for other concessions, such as a limit on Soviet SS-20 missile deployments. Since the issue has not been settled, but merely postponed, further thought should be given to the potential costs and benefits of an eventual deployment. Following a lengthy discussion of all aspects of the issue, the answers for the use of the neutron bomb and as to whether it will make Europe and America more secure remain unanswered. (MCW)« less

Suicide bombing attacks: update and modifications to the protocol.

PubMed

Almogy, Gidon; Belzberg, Howard; Mintz, Yoaz; Pikarsky, Alon K; Zamir, Gideon; Rivkind, Avraham I

2004-03-01

To review the experience of a large-volume trauma center in managing and treating casualties of suicide bombing attacks. The threat of suicide bombing attacks has escalated worldwide. The ability of the suicide bomber to deliver a relatively large explosive load accompanied by heavy shrapnel to the proximity of his or her victims has caused devastating effects. The authors reviewed and analyzed the experience obtained in treating victims of suicide bombings at the level I trauma center of the Hadassah University Hospital in Jerusalem, Israel from 2000 to 2003. Evacuation is usually rapid due to the urban setting of these attacks. Numerous casualties are brought into the emergency department over a short period. The setting in which the device is detonated has implications on the type of injuries sustained by survivors. The injuries sustained by victims of suicide bombing attacks in semi-confined spaces are characterized by the degree and extent of widespread tissue damage and include multiple penetrating wounds of varying severity and location, blast injury, and burns. The approach to victims of suicide bombings is based on the guidelines for trauma management. Attention is given to the moderately injured, as these patients may harbor immediate life-threatening injuries. The concept of damage control can be modified to include rapid packing of multiple soft-tissue entry sites. Optimal utilization of manpower and resources is achieved by recruiting all available personnel, adopting a predetermined plan, and a centrally coordinated approach. Suicide bombing attacks seriously challenge the most experienced medical facilities.

Establishment and formation of fog-dependent Tillandsia landbeckii dunes in the Atacama Desert: Evidence from radiocarbon and stable isotopes

NASA Astrophysics Data System (ADS)

Latorre, Claudio; GonzáLez, AngéLica L.; Quade, Jay; FariñA, José M.; Pinto, Raquel; Marquet, Pablo A.

2011-09-01

Extensive dune fields made up exclusively of the bromeliad Tillandsia landbeckii thrive in the Atacama Desert, one of the most extreme landscapes on earth. These plants survive by adapting exclusively to take in abundant advective fog and dew as moisture sources. Although some information has been gathered regarding their modern distribution and adaptations, very little is known about how these dune systems actually form and accumulate over time. We present evidence based on 20 radiocarbon dates for the establishment age and development of five different such dune systems located along a ˜215 km transect in northern Chile. Using stratigraphy, geochronology and stable C and N isotopes, we (1) develop an establishment chronology of these ecosystems, (2) explain how the unique T. landbeckii dunes form, and (3) link changes in foliar δ15N values to moisture availability in buried fossil T. landbeckii layers. We conclude by pointing out the potential that these systems have for reconstructing past climate change along coastal northern Chile during the late Holocene.

Chronology and ancient feeding ecology of two upper Pleistocene megamammals from the Brazilian Intertropical Region

NASA Astrophysics Data System (ADS)

de Melo França, Lucas; Trindade Dantas, Mário André; Bocchiglieri, Adriana; Cherckinsky, Alexander; de Souza Ribeiro, Adauto; Bocherens, Hervé

2014-09-01

In Brazilian Intertropical Region (BIR) fossil remains of the giant ground sloth Eremotherium laurillardi (Lund, 1842) and of the proboscidean Notiomastodon platensis (Ameghino, 1888) are the most abundant among megaherbivores. However, the paleoecology of both species needs to be better understood to enlighten why these species disappear in the end of the Pleistocene, an issue that is still debated. During the last decades, the carbon and oxygen stable isotopes have been increasingly being used to obtain paleoecological information about extinct animals, although this information is in most cases dissociated from chronological data. Thus, the main objective of this study is to contribute to the knowledge about feeding ecology and chronology of E. laurillardi and N. platensis within BIR. For each fossil sample we performed stable isotopes analyses (δ13C/δ18O) and radiocarbon dating (14C with AMS). The results showed that N. platensis occurred between 12,125 and 19,594 cal yr BP and exhibited a grazer diet (δ13C = -1.1‰-1.3‰), while E. laurillardi lived between 11,084 and 27,690 cal yr BP, with a mixed feeder diet (C3/C4 plants; values ratio δ13C = -7.7‰ to -3.3‰). The δ18O values of N. platensis ranged between 2.20‰ and 3.60‰, while the values of E. laurillardi ranged between -3.10‰ and -1.10‰. Neither species did exhibit differences in its diet through time, which suggests that the vegetational composition of this locality did not vary in the late Pleistocene. Both species were living in an open environment, rich in herbaceous plants (C4 plants) and with tree and shrub with disjoint distribution, maybe similar to some parts of recent Caatinga, where they have partitioned the spatial and feeding niches.

Captives of Their Fantasies: The German Atomic Bomb Scientists

NASA Astrophysics Data System (ADS)

Klotz, Irving M.

1997-02-01

When the Nazi government collapsed in May, 1945, an Allied intelligence mission took into custody nine of the German scientists who played key roles in the German atomic bomb project. Under great secrecy these men were confined in a large country house, Farm Hall, near Cambridge (England), and their conversations were recorded surreptitiously by hidden microphones in every room. The transcripts were kept TOP SECRET for 47 years and were finally released recently. They give fascinating insights into the personalities of the guests and invaluable information on what the Germans really understood about the physics and chemistry of a nuclear reactor and an atomic bomb. The Farm Hall transcripts clearly establish that (a) the Germans on August 6, 1945 did not believe that the Allies had exploded an atomic bomb over Hiroshima that day; (b) they never succeeded in constructing a self-sustaining nuclear reactor; (c) they were confused about the differences between an atomic bomb and a reactor; (d) they did not know how to correctly calculate the critical mass of a bomb; (e) they thought that "plutonium" was probably element 91. The Farm Hall transcripts contradict the self-serving and sensationalist writings about German efforts that have appeared during the past fifty years.

[A-bomb experience and Hibakushas' lives].

PubMed

Akiba, Tadatoshi

2012-01-01

The A-bomb experience of Hiroshima may shed light on the reconstruction plan of the Eastern Japan Earthquake and Tsunami and on implementing middle to long range care plans for the victims of the catastrophe. An important element in the success of Hiroshima's reconstruction was the understanding of the realities of everyday life of citizens and hibakusha by local and national government, and incorporation of those points of view into the reconstruction plan. Sharing of accurate and fair information about the disaster, restoration, and reconstruction with citizens was and still is a prerequisite for success. To convey learned lessons from the Hiroshima experience, three books are helpful: "A-bomb Mayor" by Shinzo Hamai, "The Meaning of Survival" compiled by the Chugoku Shimbun and "The Children of the A-bomb" compiled by Arata Osada. They help understand the history of hibakusha psychology from the point of view of their everyday lives and may help those affected by the Earthquake and Tsunami. To summarize the history of psychological changes among the hibakusha, three key transitional pairs of statements used widely by them over the span of 66 years help show the change in their attitude and emotional outlook. Each pair consists of an expression from the period immediately following the bombing and a second more recent expression: (1) Transition from "I would rather die." to "I am glad I am alive." (2) Transition from "I would rather forget." to "We should not forget." (3) Transition from "You will understand if you are a victim." to "No one else should ever suffer as we did".

A complete terrestrial radiocarbon record for 11.2 to 52.8 kyr B.P.

PubMed

Bronk Ramsey, Christopher; Staff, Richard A; Bryant, Charlotte L; Brock, Fiona; Kitagawa, Hiroyuki; van der Plicht, Johannes; Schlolaut, Gordon; Marshall, Michael H; Brauer, Achim; Lamb, Henry F; Payne, Rebecca L; Tarasov, Pavel E; Haraguchi, Tsuyoshi; Gotanda, Katsuya; Yonenobu, Hitoshi; Yokoyama, Yusuke; Tada, Ryuji; Nakagawa, Takeshi

2012-10-19

Radiocarbon ((14)C) provides a way to date material that contains carbon with an age up to ~50,000 years and is also an important tracer of the global carbon cycle. However, the lack of a comprehensive record reflecting atmospheric (14)C prior to 12.5 thousand years before the present (kyr B.P.) has limited the application of radiocarbon dating of samples from the Last Glacial period. Here, we report (14)C results from Lake Suigetsu, Japan (35°35'N, 135°53'E), which provide a comprehensive record of terrestrial radiocarbon to the present limit of the (14)C method. The time scale we present in this work allows direct comparison of Lake Suigetsu paleoclimatic data with other terrestrial climatic records and gives information on the connection between global atmospheric and regional marine radiocarbon levels.

Incident-related television viewing and psychiatric disorders in Oklahoma City bombing survivors.

PubMed

Pfefferbaum, Betty; North, Carol S; Pfefferbaum, Rose L; Jeon-Slaughter, Haekyung; Houston, J Brian; Regens, James L

2012-01-01

The objective of this study was to examine terrorism media coverage and psychiatric outcomes in directly-exposed terrorism survivors. The study used (1) self-report questionnaires to retrospectively assess event-related media behaviors and reactions in a cross sectional design and (2) longitudinal structured diagnostic interviews to assess psychopathologic outcomes. The participants were 99 directly-exposed Oklahoma City bombing survivors who were initially studied six months after the 1995 incident. Though a fear reaction to bombing-related television coverage and fear-driven discontinuation of bombing-related media contact were associated with diagnostic outcomes, the number of hours viewing bombing-related television coverage in the first week after the event was not associated with the prevalence of bombing-related posttraumatic stress disorder or post-bombing major depressive disorder during the seven years post event. The results raise doubt about the effects of quantified incident-related television viewing on clinically-significant emotional outcomes in directly-exposed terrorism survivors.

A prospective study of long-term health outcomes among Oklahoma City bombing survivors.

PubMed

Shariat, S; Mallonee, S; Kruger, E; Farmer, K; North, C

1999-04-01

A follow-up study was conducted to identify long-term physical and emotional outcomes among Oklahoma City bombing survivors. Baseline data were gathered by the Oklahoma State Department of Health in 1995. Follow-up data were gathered by telephone interviews of survivors from 1-1/2 to 3 years after the bombing. The frequency of medical diagnoses, symptoms, medical cost, physical and social life changes, and services utilized since the bombing were assessed. A total of 494 persons were interviewed, 92 percent had been physically injured in the bombing. Seventy-nine percent of persons interviewed rated their general health status as "good," "very good," or "excellent." Overall, one-fourth to one-third of survivors reported being newly diagnosed with audiologic changes, anxiety, and depression since the bombing. One-third of persons reported preexisting medical conditions that had worsened since the bombing including depression (26%) and asthma/bronchitis (22%). The most frequently reported posttraumatic stress disorder symptoms were "being jumpy or easily startled" and "recurring distressful thoughts of the bombing." The most frequently utilized medical services were psychological counseling (63%) and audiology services (48%). Total costs were estimated of $ 5.7 million. Overall, persons who had been hospitalized with bombing injuries reported higher rates of diagnoses, symptoms, and services utilization. These findings suggest that a large proportion of survivors of a terrorist bombing, especially those seriously injured, will experience long-term physical and/or emotional outcomes and increased need for treatment for bombing-related medical conditions. All survivors should be carefully assessed over time for auditory damage, depression, anxiety, and posttraumatic stress disorder.

Radiocarbon dating of plant macrofossils from tidal-marsh sediment

USGS Publications Warehouse

Kemp, A.C.; Nelson, Alan R.; Horton, B.P.

2013-01-01

Tidal-marsh sediment is an archive of Holocene environmental changes, including movements of sea and land levels, and extreme events such as hurricanes, earthquakes, and tsunamis. Accurate and precise radiocarbon dating of environmental changes is necessary to estimate rates of change and the recurrence interval (frequency) of events. Plant macrofossils preserved in growth position (or deposited soon after death) in tidal-marsh sediment are ideal samples for dating such changes. In this chapter, we focus on the selection of plant macrofossils for radiocarbon dating and the application of ages from different types of macrofossils to varied research projects, and make recommendations for selection and preparation of tidal-marsh samples for dating.

Cosmic strings and chronology protection

NASA Astrophysics Data System (ADS)

Grant, James D. E.

1993-03-01

A space consisting of two rapidly moving cosmic strings has recently been constructed by Gott that contains closed timelike curves. The global structure of this space is analyzed and it is found that, away from the strings, the space is identical to a generalized Misner space. The vacuum expectation value of the energy-momentum tensor for a conformally coupled scalar field is calculated on this generalized Misner space. It is found to diverge very weakly on the chronology horizon, but more strongly on the polarized hypersurfaces. The divergence on the polarized hypersurfaces is strong enough that when the proper geodesic interval around any polarized hypersurface is of the order of the Planck length squared, the perturbation to the metric caused by the back reaction will be of the order one. Thus we expect the structure of the space will be radically altered by the back reaction before quantum gravitational effects become important. This suggests that Hawking's ``chronology protection conjecture'' holds for spaces with a noncompactly generated chronology horizon.

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses.

PubMed

Boyd, Thomas J; Montgomery, Michael T; Cuenca, Richard H; Hagimoto, Yutaka

2016-10-21

A method is described which uses the absence of radiocarbon in industrial chemicals and fuels made from petroleum feedstocks which frequently contaminate the environment. This radiocarbon signal - or rather the absence of signal - is evenly distributed throughout a contaminant source pool (unlike an added tracer) and is not impacted by biological, chemical or physical processes (e.g., the 14 C radioactive decay rate is immutable). If the fossil-derived contaminant is fully degraded to CO2, a harmless end-product, that CO2 will contain no radiocarbon. CO2 derived from natural organic matter (NOM) degradation will reflect the NOM radiocarbon content (usually <30,000 years old). Given a known radiocarbon content for NOM (a site background), a two end-member mixing model can be used to determine the CO2 derived from a fossil source in a given soil gas or groundwater sample. Coupling the percent CO2 derived from the contaminant with the CO2 respiration rate provides an estimate for the total amount of contaminant degraded per unit time. Finally, determining a zone of influence (ZOI) representing the volume from which site CO2 is collected allows determining the contaminant degradation per unit time and volume. Along with estimates for total contaminant mass, this can ultimately be used to calculate time-to-remediate or otherwise used by site managers for decision-making.

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

PubMed Central

Boyd, Thomas J.; Montgomery, Michael T.; Cuenca, Richard H.; Hagimoto, Yutaka

2016-01-01

A method is described which uses the absence of radiocarbon in industrial chemicals and fuels made from petroleum feedstocks which frequently contaminate the environment. This radiocarbon signal — or rather the absence of signal — is evenly distributed throughout a contaminant source pool (unlike an added tracer) and is not impacted by biological, chemical or physical processes (e.g., the 14C radioactive decay rate is immutable). If the fossil-derived contaminant is fully degraded to CO2, a harmless end-product, that CO2 will contain no radiocarbon. CO2 derived from natural organic matter (NOM) degradation will reflect the NOM radiocarbon content (usually <30,000 years old). Given a known radiocarbon content for NOM (a site background), a two end-member mixing model can be used to determine the CO2 derived from a fossil source in a given soil gas or groundwater sample. Coupling the percent CO2 derived from the contaminant with the CO2 respiration rate provides an estimate for the total amount of contaminant degraded per unit time. Finally, determining a zone of influence (ZOI) representing the volume from which site CO2 is collected allows determining the contaminant degradation per unit time and volume. Along with estimates for total contaminant mass, this can ultimately be used to calculate time-to-remediate or otherwise used by site managers for decision-making. PMID:27805601

Late Quaternary geomorphic history of a glacial landscape - new sedimentary and chronological data from the Cordillera de Cochabamba (Bolivia)

NASA Astrophysics Data System (ADS)

May, J.-H.; Preusser, F.; Zech, R.; Ilgner, J.; Veit, H.

2009-04-01

Throughout the Central Andes, glacial landscapes have long been used for the reconstruction of Late Quaternary glaciations and landscape evolution. Much work has focused on the Andes in Peru, Chile and the Bolivian Altiplano, whereas relatively little data has been published on glaciation history in the eastern Andean ranges and slopes. Even less is known with regard to the postglacial evolution of these glacial landscapes. In the Cordillera de Cochabamba (Bolivia), local maximum advances probably peaked around 20-25 ka BP and were followed by significant readvances between ~12-16 ka BP. This generally points to temperature controlled maximum glacial advances along the humid eastern slopes of the Central Andes, which is supported by glacier-climate-modelling studies. However, most studies include only marginal information with regard to the complex geomorphic and sedimentary situation in the Cordillera de Cochabamba. Furthermore, the chronological results are afflicted with several methodological uncertainties inherent to surface exposure dating and call for application of alternative, independent age dating methods. Therefore this study aims at i) documenting and interpreting the complex glacial geomorphology of the Huara Loma valley in the Cordillera de Cochabamba (Bolivia), ii) analyzing the involved units of glacial sediments, and iii) improving the chronological framework by applying optically stimulated luminescence (OSL) and radiocarbon dating (14C). For this purpose, geomorphic mapping was combined with field documentation of sedimentary profiles. The involved sediments were subject to geochemical and mineralogical analysis in order to deduce information on their erosional and weathering histories. In addition, the interpretation of OSL ages from glacial and proglacial sediments integrated several methodological procedures with regard to sample preparation and statistical analysis of the measurements in order to increase the degree of confidence. These

Integrating chronological uncertainties for annually laminated lake sediments using layer counting, independent chronologies and Bayesian age modelling (Lake Ohau, South Island, New Zealand)

NASA Astrophysics Data System (ADS)

Vandergoes, Marcus J.; Howarth, Jamie D.; Dunbar, Gavin B.; Turnbull, Jocelyn C.; Roop, Heidi A.; Levy, Richard H.; Li, Xun; Prior, Christine; Norris, Margaret; Keller, Liz D.; Baisden, W. Troy; Ditchburn, Robert; Fitzsimons, Sean J.; Bronk Ramsey, Christopher

2018-05-01

Annually resolved (varved) lake sequences are important palaeoenvironmental archives as they offer a direct incremental dating technique for high-frequency reconstruction of environmental and climate change. Despite the importance of these records, establishing a robust chronology and quantifying its precision and accuracy (estimations of error) remains an essential but challenging component of their development. We outline an approach for building reliable independent chronologies, testing the accuracy of layer counts and integrating all chronological uncertainties to provide quantitative age and error estimates for varved lake sequences. The approach incorporates (1) layer counts and estimates of counting precision; (2) radiometric and biostratigrapic dating techniques to derive independent chronology; and (3) the application of Bayesian age modelling to produce an integrated age model. This approach is applied to a case study of an annually resolved sediment record from Lake Ohau, New Zealand. The most robust age model provides an average error of 72 years across the whole depth range. This represents a fractional uncertainty of ∼5%, higher than the <3% quoted for most published varve records. However, the age model and reported uncertainty represent the best fit between layer counts and independent chronology and the uncertainties account for both layer counting precision and the chronological accuracy of the layer counts. This integrated approach provides a more representative estimate of age uncertainty and therefore represents a statistically more robust chronology.

Vulcanism and Radiocarbon Dates

DOE R&D Accomplishments Database

Libby, L. M.; Libby, W. F.

1972-10-01

We consider whether the long term perturbation of radiocarbon dates, which is known to be approximately a sin function of period about 8000 years and amplitude of about 8% peak-to-peak, could have been caused in any major part by vulcanism. We conclude that this is not the case. On the contrary, present day volcanoes are a far less important source of inert CO{sub 2} (about 100 fold less) than is man's burning of fossil fuels which has caused the Suess dilution of about 2%. (auth)

26. BOMBS IN CRATE IN BUILDING 1607. VIEW TO NORTHWEST. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. BOMBS IN CRATE IN BUILDING 1607. VIEW TO NORTHWEST. - Rocky Mountain Arsenal, Cluster Bomb Assembly-Filling-Storage Building, 3500 feet South of Ninth Avenue; 2870 feet East of D Street, Commerce City, Adams County, CO

An improved chronology for the Lateglacial palaeoenvironmental record of Lake Haemelsee, Germany: challenges for independent site comparisons

NASA Astrophysics Data System (ADS)

Lane, Christine; Brauer, Achim; Ramsey Christopher, Bronk; Engels, Stefan; Haliuc, Aritina; Hoek, Wim; Hubay, Katalin; Jones, Gwydion; Sachse, Dirk; Staff, Richard; Turner, Falko; Wagner-Cremer, Frederike

2016-04-01

Exploring temporal and spatial variability of environmental response to climatic changes requires the comparison of widespread palaeoenvironmental sequences on their own, independently-derived, age models. High precision age-models can be constructed using statistical methods to combine absolute and relative age estimates measured using a range of techniques. Such an approach may help to highlight otherwise unrecognised uncertainties, where a single dating method has been applied in isolation. Radiocarbon dating, tephrochronology and varve counting have been combined within a Bayesian depositional model to build a chronology for a sediment sequence from Lake Haemelsee (Northern Germany) that continuously covers the entire Lateglacial and early Holocene. Each of the dating techniques used brought its own challenges. Radiocarbon dates provide the only absolute ages measured directly in the record, however a low macrofossil content led to small sample sizes and a limited number of low precision dates. A floating varved interval provided restricted but very precise relative dating for sediments covering the Allerød to Younger Dryas transition. Well-spaced, visible and crypto- tephra layers, including the widespread Laacher See , Vedde Ash, Askja-S and Saksunarvatn tephra layers, allow absolute ages for the tephra layers established in other locations to be imported into the Haemelsee sequence. These layers also provide multiple tie-lines that allow the Haemelsee sequences to be directly compared at particular moments in time, and within particular intervals, to other important Lateglacial archives. However, selecting the "best" published tephra ages to use in the Haemelsee age model is not simple and risks biasing comparison of the palaeoenvironmental record to fit one or another comparative archive. Here we investigate the use of multiple age models for the Haemelsee record, in order to retain an independent approach to investigating the environmental transitions of

Impacts of post-glacial lake drainage events and revised chronology of the Champlain Sea episode 13-9 ka

USGS Publications Warehouse

Cronin, T. M.; Manley, P.L.; Brachfeld, S.; Manley, T.O.; Willard, D.A.; Guilbault, J.-P.; Rayburn, J.A.; Thunell, R.; Berke, M.

2008-01-01

Lithologic, CHIRP (Compressed High Intensity Radar Pulse) sonar, paleomagnetic, stable isotopic and micropaleontological analyses of sediment cores from Lake Champlain (New York, Vermont) were used to determine the age of the post-glacial Champlain Sea marine episode, the timing of salinity changes and their relationship to freshwater discharge from mid-continent glacial lakes. Calibrated radiocarbon ages on plant material provide an improved post-glacial chronology overcoming problems from shell ages caused by carbon reservoir effects up to 1500 yr. The final drainage of glacial Lake Vermont and the inception of marine conditions occurred ∼ 13.1–12.8 ka (kiloannum, calendar years) and a sharp decrease in Champlain Sea salinity from ∼ 25 to 7–8 psu (practical salinity units) occurred approximately 11.4–11.2 ka. Reduced salinity was most likely caused by rapid freshwater inflow eastward from glacial Lake Algonquin into the Champlain Basin. The timing of inferred freshwater event coincides with the widespread climatic cooling called the Preboreal Oscillation.

A new luminescence dating chronology for the Rhafas cave site (NE Morocco): Insights into Palaeolithic human cultural change under varying palaeoenvironmental conditions in the Maghreb

NASA Astrophysics Data System (ADS)

Dörschner, Nina; Fitzsimmons, Kathryn E.; Ditchfield, Peter; McLaren, Sue J.; Steele, Teresa E.; Zielhofer, Christoph; McPherron, Shannon P.; Bouzouggar, Abdeljalil; Hublin, Jean-Jacques

2016-04-01

Archaeological sites in northern Africa provide a rich record that is of increasing importance for current debates relating to the origins of modern human behaviour and to Out of Africa human dispersal events. Particular interest is placed on the cultural transition between the North African Middle Stone Age (MSA) and Late Stone Age (LSA), and the need for accurately defined chronologies, however the timing and nature of Palaeolithic human behaviour and dispersal across north-western Africa (the Maghreb) and potential correlation with environmental conditions remain poorly understood. The inland cave site of Rhafas (Morocco) preserves a long stratified sequence providing valuable chronological information about cultural changes in the Maghreb spanning the North African MSA through to the Neolithic. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz grains to the cave deposits of Rhafas as well as to a section on the terrace in front of the cave entrance. Single grain OSL dating reliably constrains the timing of technocomplexes beyond the limits of radiocarbon by directly dating sediment associated with archaeological traces. We combine OSL dating with multi-proxy geological investigations (XRF, grain size analyses, stable isotopes, thin sections) to investigate site formation processes and reconstruct palaeoenvironmental conditions during human occupation phases at Rhafas. Our results indicate that the occupation of the site started at least in MIS 6 during a phase of relatively arid environmental conditions. Climatic amelioration after c.140 ka is associated with a change in sediment geochemistry at the site, most likely linked to a change in sediment source due to shifting wind directions. Tanged pieces - typical for the classical Aterian technocomplex - start to occur in the archaeological sequence in MIS 5, consistent with previously published chronological data from the Maghreb. From 55 ka, climatic conditions were

Bombings specific triage (Bost Tool) tool and its application by healthcare professionals.

PubMed

Sanjay, Jaiswal; Ankur, Verma; Tamorish, Kole

2015-01-01

Bombing is a unique incident which produces unique patterns, multiple and occult injuries. Death often is a result of combined blast, ballistic and thermal effect injuries. Various natures of injury, self referrals and arrival by private transportation may lead to "wrong triage" in the emergency department. In India there has been an increase in incidence of bombing in the last 15 years. There is no documented triage tool from the National Disaster Management Authority of India for Bombings. We have tried to develop an ideal bombing specific triage tool which will guide the right patients to the right place at the right time and save more lives. There are three methods of studying the triage tool: 1) real disaster; 2) mock drill; 3) table top exercise. In this study, a table top exercise method was selected. There are two groups, each consisting of an emergency physician, a nurse and a paramedic. By using the proportion test, we found that correct triaging was significantly different (P=0.005) in proportion between the two groups: group B (80%) with triage tool performed better in triaging the bomb blast victims than group A (50%) without the bombing specific triage tool performed. Development of bombing specific triage tool can reduce under triaging.

Bombings specific triage (Bost Tool) tool and its application by healthcare professionals

PubMed Central

Sanjay, Jaiswal; Ankur, Verma; Tamorish, Kole

2015-01-01

BACKGROUND: Bombing is a unique incident which produces unique patterns, multiple and occult injuries. Death often is a result of combined blast, ballistic and thermal effect injuries. Various natures of injury, self referrals and arrival by private transportation may lead to “wrong triage” in the emergency department. In India there has been an increase in incidence of bombing in the last 15 years. There is no documented triage tool from the National Disaster Management Authority of India for Bombings. We have tried to develop an ideal bombing specific triage tool which will guide the right patients to the right place at the right time and save more lives. METHODS: There are three methods of studying the triage tool: 1) real disaster; 2) mock drill; 3) table top exercise. In this study, a table top exercise method was selected. There are two groups, each consisting of an emergency physician, a nurse and a paramedic. RESULTS: By using the proportion test, we found that correct triaging was significantly different (P=0.005) in proportion between the two groups: group B (80%) with triage tool performed better in triaging the bomb blast victims than group A (50%) without the bombing specific triage tool performed. CONCLUSION: Development of bombing specific triage tool can reduce under triaging. PMID:26693264

Agriculture, population growth, and statistical analysis of the radiocarbon record.

PubMed

Zahid, H Jabran; Robinson, Erick; Kelly, Robert L

2016-01-26

The human population has grown significantly since the onset of the Holocene about 12,000 y ago. Despite decades of research, the factors determining prehistoric population growth remain uncertain. Here, we examine measurements of the rate of growth of the prehistoric human population based on statistical analysis of the radiocarbon record. We find that, during most of the Holocene, human populations worldwide grew at a long-term annual rate of 0.04%. Statistical analysis of the radiocarbon record shows that transitioning farming societies experienced the same rate of growth as contemporaneous foraging societies. The same rate of growth measured for populations dwelling in a range of environments and practicing a variety of subsistence strategies suggests that the global climate and/or endogenous biological factors, not adaptability to local environment or subsistence practices, regulated the long-term growth of the human population during most of the Holocene. Our results demonstrate that statistical analyses of large ensembles of radiocarbon dates are robust and valuable for quantitatively investigating the demography of prehistoric human populations worldwide.

Holocene age of the Yuha burial: Direct radiocarbon determinations by accelerator mass spectrometry

USGS Publications Warehouse

Stafford, Thomas W.; Jull, A.J.T.; Zabel, T.H.; Donahue, D.J.; Duhamel, R.C.; Brendel, K.; Haynes, C.V.; Bischoff, J.L.; Payen, L.A.; Taylor, R.E.

1984-01-01

The view that human populations may not have arrived in the Western Hemisphere before about 12,000 radiocarbon yr BP1,2 has been challenged by claims of much greater antiquity for a small number of archaeological sites and human skeleton samples. One such site is the Homo sapiens sapiens cairn burial excavated in 1971 from the Yuha desert, Imperial County, California3-5. Radiocarbon analysis of caliche coating one of the bones of the skeleton yielded a radiocarbon age of 21,500??1,000 yr BP4, while radiocarbon and uranium series analyses of caliche coating a cairn boulder yielded ages of 22,125??400 and 19,000??3,000 yr BP, respectively5. The late Pleistocene age assignment to the Yuha burial has been challenged by comparing the cultural context of the burial with other cairn burials in the same region6, on the basis of the site's geomorphological context and from radiocarbon analyses of soil caliches. 7,8 In rebuttal, arguments in defence of the original age assignment have been presented9,10 as well as an amino acid racemization analysis on the Yuha skeleton indicating an age of 23,600??2,600 yr BP11. The tandem accelerator mass spectrometer at the University of Arizona has now been used to measure the ratio of 14C/13C in several organic and inorganic fractions of post-cranial bone from the Yuha H. sapiens sapiens skeleton. Isotope ratios from six chemical fractions all yielded radiocarbon ages for the skeleton of less than 4,000 yr BP. These results indicate that the Yuha skeleton is of Holocene age, in agreement with the cultural context of the burial, and in disagreement with the previously assigned Pleistocene age of 19,000-23,000 yr. ?? 1984 Nature Publishing Group.

U.S. Army Air Forces in World War II. Combat Chronology 1941-1945

DTIC Science & Technology

1991-01-01

B-17’s and B-24’s bomb M/Ys at Troyes , Reims, Sarreguemines, Metz, Liege, and Brussels. 5/1/44 Ninth AF The last of the 11 bomb gps (8 medium and 3...weather and photo rcn over Shimushu and bomb Matsuwa area. 5/25/44 Eighth AF 859 B-17’s and B-24’s operating in 4 forces bomb M/Ys at Mulhouse, Troyes ...Dessau, Oschersleben, Halberstadt, Rotenburg, Zwischenahn, Oldenburg, Diepholz, and Handorf; M/Ys at Brussels, Troyes , and Reims; V-weapon sites at Watten

ESR dosimetry for atomic bomb survivors and radiologic technologists

NASA Astrophysics Data System (ADS)

Tatsumi-Miyajima, Junko

1987-06-01

An individual absorbed dose for atomic bomb (A-bomb) survivors and radiologic technologists has been estimated using a new personal dosimetry. This dosimetry is based on the electron spin resonance (ESR) spectroscopy of the CO 33- radicals, which are produced in their teeth by radiation. Measurements were carried out to study the characteristics of the dosimetry; the ESR signals of the CO 33- radicals were stable and increased linearly with the radiation dose. In the evaluation of the absorbed dose, the ESR signals were considered to be a function of photon energy. The absorbed doses in ten cases of A-bomb victims and eight cases of radiologic technologists were determined. For A-bomb survivors, the adsorbed doses, which were estimated using the ESR dosimetry, were consistent with the ones obtained using the calculations of the tissue dose in air of A-bomb, and also with the ones obtained using the chromosome measurements. For radiologic technologists, the absorbed doses, which were estimated using the ESR dosimetry, agreed with the ones calculated using the information on the occupational history and conditions. The advantages of this method are that the absorbed dose can be directly estimated by measuring the ESR signals obtained from the teeth of persons, who are exposed to radiation. Therefore, the ESR dosimetry is useful to estimate the accidental exposure and the long term cumulative dose.

New radiocarbon ages from cirques in Colorado Front Range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, P.T.; Birkeland, P.W.; Caine, N.

The authors recovered sediment cores 3.1 m long from Blue Lake ([approximately]37m water depth, [approximately]3,445m a.s.l., 40[degree]5 minutes 20 seconds N, 105[degree]37 minutes 08 seconds W) and 2.7m long from Lake Dorothy ([approximately]35m water depth, [approximately]3,675m a.s.l., 40[degree]00 minutes 46 seconds N, 105[degree]41 minutes 11 seconds W). A light-weight percussion coring system suspended from perlon ropes was used because of sediment thicknesses, water depths, and ski-backpacking requirements. Lake ice provided a stable coring platform. One purpose of the project is provision of a high-resolution record of environmental change in the subalpine/alpine ecotone during the Holocene, under the auspices of themore » Niwot Ridge Long-Term Ecological Research program. The sediment cores also provide minimum-limiting radiocarbon ages for deglaciation of cirques and the deposits that impound their tarns. Here the authors report on this second purpose. The Blue Lake core bottomed in sandy, gray, inorganic sediment, presumably glacial diamict. A bulk sample from 2.8--2.9m depth yielded a conventional radiocarbon age of 12,275[+-]345 yrs BP. Thus, ice retreated from the site by 12 ka. Since 12 ka both glacial and rock-glacial sediments have been deposited upvalley; some of these events may be recognized in the core. In contrast, the Lake Dorothy core did not penetrate gray inorganic diamict and is entirely organic-rich. A bulk sample from 2.65--2.7m depth yielded a conventional radiocarbon age of 10,910 [+-] 320 yrs BP. Thus, the moraines impounding the lake are 2--3 times older than suggested by a combination of relative-age methods and one radiocarbon age from surface sediments.« less

A comparison of chronologies from tree rings

Treesearch

Kurt H. Riitters

1990-01-01

Forty-five-year ring width index chronologies were estimated by five mean-value functions applied to 183 ring width series from four similar sites. The effects of autocorrelation on the comparisons among mean-value functions were explored by fitting box-Jenkins models to individual-tree index services prior to pooling (prewhitening), and to the pooled chronologies...

Wind-Tunnel Investigation of the Effects on the Aerodynamic Characteristics of Modifications to a Model of a Bomb Mounted on a Wing-Fuselage Model and to a Model of the Bomb Alone

NASA Technical Reports Server (NTRS)

King, Thomas J., Jr.

1954-01-01

An investigation was conducted in the Langley high-speed 7- by 10-foot tunnel to determine effects of modifications to a bomb model (particularly with regard to drag) when mounted on a wing-fuselage model and tested at Mach numbers from 0.70 to 1.10. In addition, the static longitudinal stability characteristics of several configurations of a larger scale model of the bomb alone were obtained over a Mach number range from 0.50 to 0.95. The results obtained for the wing-fuselage-bomb model indicate that large reductions in installation drag were obtained for the wing-fuselage-bomb model when the flat nose of the basic bomb was replaced by rounded or pointed noses of various calibers. Shortening the mounting pylon gave further decreases in the installation drag. The tests of the bomb alone indicated that only the flat-nose configurations were stable over the greater part of the Mach number range. Nose-shape modifications which improved the drag also caused the bombs to become unstable at low angles of attack. The stability of the low-drag bomb configurations could be improved by lengthening the cylindrical portion of the body behind the center of gravity.

Triggering soft bombs at the LHC

DOE PAGES

Knapen, Simon; Griso, Simone Pagan; Papucci, Michele; ...

2017-08-18

Very high multiplicity, spherically-symmetric distributions of soft particles, with p T ~ few×100 MeV, may be a signature of strongly-coupled hidden valleys that exhibit long, efficient showering windows. With traditional triggers, such ‘soft bomb’ events closely resemble pile-up and are therefore only recorded with minimum bias triggers at a very low efficiency. We demonstrate a proof-of-concept for a high-level triggering strategy that efficiently separates soft bombs from pile-up by searching for a ‘belt of fire’: a high density band of hits on the innermost layer of the tracker. Seeding our proposed high-level trigger with existing jet, missing transverse energy ormore » lepton hardware-level triggers, we show that net trigger efficiencies of order 10% are possible for bombs of mass several × 100 GeV. We also consider the special case that soft bombs are the result of an exotic decay of the 125 GeV Higgs. The fiducial rate for ‘Higgs bombs’ triggered in this manner is marginally higher than the rate achievable by triggering directly on a hard muon from associated Higgs production.« less

Triggering soft bombs at the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knapen, Simon; Griso, Simone Pagan; Papucci, Michele

Very high multiplicity, spherically-symmetric distributions of soft particles, with p T ~ few×100 MeV, may be a signature of strongly-coupled hidden valleys that exhibit long, efficient showering windows. With traditional triggers, such ‘soft bomb’ events closely resemble pile-up and are therefore only recorded with minimum bias triggers at a very low efficiency. We demonstrate a proof-of-concept for a high-level triggering strategy that efficiently separates soft bombs from pile-up by searching for a ‘belt of fire’: a high density band of hits on the innermost layer of the tracker. Seeding our proposed high-level trigger with existing jet, missing transverse energy ormore » lepton hardware-level triggers, we show that net trigger efficiencies of order 10% are possible for bombs of mass several × 100 GeV. We also consider the special case that soft bombs are the result of an exotic decay of the 125 GeV Higgs. The fiducial rate for ‘Higgs bombs’ triggered in this manner is marginally higher than the rate achievable by triggering directly on a hard muon from associated Higgs production.« less

24. INTERIOR DETAIL OF BUILDING 1607, SHOWING BOMBS AND CRATES. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. INTERIOR DETAIL OF BUILDING 1607, SHOWING BOMBS AND CRATES. VIEW TO SOUTHWEST. - Rocky Mountain Arsenal, Cluster Bomb Assembly-Filling-Storage Building, 3500 feet South of Ninth Avenue; 2870 feet East of D Street, Commerce City, Adams County, CO

Martian Chronology: Goals for Investigations from a Recent Multidisciplinary Workshop

NASA Technical Reports Server (NTRS)

Nyquist, L.; Doran, P. T.; Cerling, T. E.; Clifford, S. M.; Forman, S. L.; Papanastassiou, D. A.; Stewart, B. W.; Sturchio, N. C.; Swindle, T. D.

2000-01-01

The absolute chronology of Martian rocks and events is based mainly on crater statistics and remains highly uncertain. Martian chronology will be critical to building a time scale comparable to Earth's to address questions about the early evolution of the planets and their ecosystems. In order to address issues and strategies specific to Martian chronology, a workshop was held, 4-7 June 2000, with invited participants from the planetary, geochronology, geochemistry, and astrobiology communities. The workshop focused on identifying: a) key scientific questions of Martian chronology; b) chronological techniques applicable to Mars; c) unique processes on Mars that could be exploited to obtain rates, fluxes, ages; and d) sampling issues for these techniques. This is an overview of the workshop findings and recommendations.

Glaucoma in atomic bomb survivors.

PubMed

Kiuchi, Yoshiaki; Yokoyama, Tomoko; Takamatsu, Michiya; Tsuiki, Eiko; Uematsu, Masafumi; Kinoshita, Hirofumi; Kumagami, Takeshi; Kitaoka, Takashi; Minamoto, Atsushi; Neriishi, Kazuo; Nakashima, Eiji; Khattree, Ravindra; Hida, Ayumi; Fujiwara, Saeko; Akahoshi, Masazumi

2013-10-01

Radiation has been associated with increases in noncancerous diseases. An effect of low-dose radiation on the prevalence of clinically detected glaucoma has not been previously reported. We therefore investigated the prevalence of glaucoma in A-bomb survivors and its possible association with radiation dose. A total of 1,589 people who participated in the clinical examination program for A-bomb survivors at the Radiation Effects Research Foundation (RERF) between October 2006 and September 2008 and who had reconstructed radiation doses, were recruited into this cross-sectional screening study. The prevalence of glaucoma and its dose-response relationship to A-bomb radiation were measured. Each subject underwent an initial screening consisting of an interview and ophthalmological examination. Questionable cases with any indication of ocular disease, including glaucoma, were referred to local hospitals for more comprehensive evaluation. A diagnosis of glaucoma was made based on specific optic disc appearance, perimetric results and other ocular findings. Of 1,589 eligible people, we detected 284 (17.9%) cases of glaucoma overall, including 36 (2.3%) cases of primary open-angle glaucoma with intraocular pressure levels greater than 21 mmHg, 226 (14.2%) cases of normal-tension glaucoma and 25 (1.6%) cases of primary angle-closure glaucoma. Seven glaucoma risk factors were examined as potential confounders but only two needed to be included in the final model. Binary regression using a generalized estimating equation method, with adjustment for gender, age, city, cataract surgery or diabetes mellitus, revealed an odds ratio at 1 Gy of 1.31 (95% confidence interval 1.11-1.53, P = 0.001) in the case of normal-tension glaucoma, but no association for other types of glaucoma. The prevalence of normal-tension glaucoma may increase with A-bomb radiation dose, but uncertainties associated with nonparticipation (59% participation) suggest caution in the interpretation of these

25. INTERIOR DETAIL OF BUILDING 1607, SHOWING BOMB CRATES AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

25. INTERIOR DETAIL OF BUILDING 1607, SHOWING BOMB CRATES AND SCALE. VIEW TO WEST. - Rocky Mountain Arsenal, Cluster Bomb Assembly-Filling-Storage Building, 3500 feet South of Ninth Avenue; 2870 feet East of D Street, Commerce City, Adams County, CO

Space Exploration Initiative: Chronology

NASA Technical Reports Server (NTRS)

McCurdy, Howard E.

1992-01-01

This chronology gives an overview of the human space exploration initiative from 1956 through 1989. Details are given for the political milestones of the initiative, including information on presidential mandates and NASA Administrator appointments.

Radiocarbon Based Ages and Growth Rates: Hawaiian Deep Sea Corals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roark, E B; Guilderson, T P; Dunbar, R B

2006-01-13

The radial growth rates and ages of three different groups of Hawaiian deep-sea 'corals' were determined using radiocarbon measurements. Specimens of Corallium secundum, Gerardia sp., and Leiopathes glaberrima, were collected from 450 {+-} 40 m at the Makapuu deep-sea coral bed using a submersible (PISCES V). Specimens of Antipathes dichotoma were collected at 50 m off Lahaina, Maui. The primary source of carbon to the calcitic C. secundum skeleton is in situ dissolved inorganic carbon (DIC). Using bomb {sup 14}C time markers we calculate radial growth rates of {approx} 170 {micro}m y{sup -1} and ages of 68-75 years on specimensmore » as tall as 28 cm of C. secundum. Gerardia sp., A. dichotoma, and L. glaberrima have proteinaceous skeletons and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using {sup 14}C we calculate a radial growth rate of 15 {micro}m y{sup -1} and an age of 807 {+-} 30 years for a live collected Gerardia sp., showing that these organisms are extremely long lived. Inner and outer {sup 14}C measurements on four sub-fossil Gerardia spp. samples produce similar growth rate estimates (range 14-45 {micro}m y{sup -1}) and ages (range 450-2742 years) as observed for the live collected sample. Similarly, with a growth rate of < 10 {micro}m y{sup -1} and an age of {approx}2377 years, L. glaberrima at the Makapuu coral bed, is also extremely long lived. In contrast, the shallow-collected A. dichotoma samples yield growth rates ranging from 130 to 1,140 {micro}m y{sup -1}. These results show that Hawaiian deep-sea corals grow more slowly and are older than previously thought.« less

Marine radiocarbon reservoir age simulations for the past 50,000 years

NASA Astrophysics Data System (ADS)

Butzin, M.; Köhler, P.; Lohmann, G.

2017-08-01

Radiocarbon (14C) dating calibration for the last glacial period largely relies on cross-dated marine 14C records. However, marine reservoirs are isotopically depleted with respect to the atmosphere and therefore have to be corrected by the Marine Radiocarbon Ages of surface waters (MRAs), whose temporal variabilities are largely unknown. Here we present simulations of the spatial and temporal variability in MRAs using a three-dimensional ocean circulation model covering the past 50,000 years. Our simulations are compared to reconstructions of past surface ocean Δ14C. Running the model with different climatic boundary conditions, we find that low-latitude to midlatitude MRAs have varied between 400 and 1200 14C years, with values of about 780 14C years at the Last Glacial Maximum. Reservoir ages exceeding 2000 14C years are simulated in the polar oceans. Our simulation results can be used as first-order approximation of the MRA variability in future radiocarbon calibration efforts.

Automatic behavior sensing for a bomb-detecting dog

NASA Astrophysics Data System (ADS)

Nguyen, Hoa G.; Nans, Adam; Talke, Kurt; Candela, Paul; Everett, H. R.

2015-05-01

Bomb-detecting dogs are trained to detect explosives through their sense of smell and often perform a specific behavior to indicate a possible bomb detection. This behavior is noticed by the dog handler, who confirms the probable explosives, determines the location, and forwards the information to an explosive ordnance disposal (EOD) team. To improve the speed and accuracy of this process and better integrate it with the EOD team's robotic explosive disposal operation, SPAWAR Systems Center Pacific has designed and prototyped an electronic dog collar that automatically tracks the dog's location and attitude, detects the indicative behavior, and records the data. To account for the differences between dogs, a 5-minute training routine can be executed before the mission to establish initial values for the k-mean clustering algorithm that classifies a specific dog's behavior. The recorded data include GPS location of the suspected bomb, the path the dog took to approach this location, and a video clip covering the detection event. The dog handler reviews and confirms the data before it is packaged up and forwarded on to the EOD team. The EOD team uses the video clip to better identify the type of bomb and for awareness of the surrounding environment before they arrive at the scene. Before the robotic neutralization operation commences at the site, the location and path data (which are supplied in a format understandable by the next-generation EOD robots—the Advanced EOD Robotic System) can be loaded into the robotic controller to automatically guide the robot to the bomb site. This paper describes the project with emphasis on the dog-collar hardware, behavior-classification software, and feasibility testing.

Self injury of extremities leading to amputation while handling local bomb.

PubMed

Bhadani, Umesh Kumar

2013-05-01

Self injury while making material which has a tendency to blast is dangerous- whether it is fire cracker or local bomb. Some villagers living nearby forest make bomb to scare wild animals to protect their pet animals. A 22-year old girl while making this kind of local bomb, got injured badly. The injury was sustained while making bomb in a sitting position with face down as it is evident form type of injury. There was lacerated injury of both hands leading to amputation of both hands above wrists. Lacerated injury was present on medial sides of both thighs and gun powder marks on face. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Epidemiological research on radiation-induced cancer in atomic bomb survivors

PubMed Central

Ozasa, Kotaro

2016-01-01

The late effects of exposure to atomic bomb radiation on cancer occurrence have been evaluated by epidemiological studies on three cohorts: a cohort of atomic bomb survivors (Life Span Study; LSS), survivors exposed in utero, and children of atomic bomb survivors (F1). The risk of leukemia among the survivors increased remarkably in the early period after the bombings, especially among children. Increased risks of solid cancers have been evident since around 10 years after the bombings and are still present today. The LSS has clarified the dose–response relationships of radiation exposure and risk of various cancers, taking into account important risk modifiers such as sex, age at exposure, and attained age. Confounding by conventional risk factors including lifestyle differences is not considered substantial because people were non-selectively exposed to the atomic bomb radiation. Uncertainty in risk estimates at low-dose levels is thought to be derived from various sources, including different estimates of risk at background levels, uncertainty in dose estimates, residual confounding and interaction, strong risk factors, and exposure to residual radiation and/or medical radiation. The risk of cancer in subjects exposed in utero is similar to that in LSS subjects who were exposed in childhood. Regarding hereditary effects of radiation exposure, no increased risk of cancers associated with parental exposure to radiation have been observed in the F1 cohort to date. In addition to biological and pathogenetic interpretations of the present results, epidemiological investigations using advanced technology should be used to further analyze these cohorts. PMID:26976124

Bomb Threat Becomes Real News.

ERIC Educational Resources Information Center

Gastaldo, Evann

1999-01-01

Discusses how the staff of the newspaper at Camarillo High School (California) covered a bomb threat at their school. Describes how they, overnight, conducted interviews, took and developed photographs, produced the layout, and published the newspaper. (RS)

Fatalities associated with home-made pipe bombs in Northern Ireland.

PubMed

Lucas, James; Crane, Jack

2008-06-01

Pipe bombs are crudely constructed improvized explosive devices which are easily made at home. They are increasingly used by terrorists and others, and may inflict serious injuries and cause death. Four fatalities have occurred in association with their use in Northern Ireland between 1998 and 2002. In 2 cases, death was due to penetrating shrapnel injuries to the chest causing laceration of the great vessels, and a third fatality occurred due to a bomb fragment penetrating the cranial cavity. A pipe bomb exploded close to the back of the head of a fourth victim and this was associated with a severe brain injury. The pathologist was able to determine the position of the victim in relation to the explosion by interpreting the pattern of injuries. It seems likely that 2 of the victims had been involved in the construction, transport, or use of the devices. A third victim was entirely innocent and had been in the process of removing a pipe bomb, which had been thrown through the window of her home, when it exploded. The fourth victim was a member of the security forces who had been struck by a bomb fragment, in the region of the right eye, during a period of sectarian unrest.

Radiocarbon Dating of the Human Eye Lens Crystallines Reveal Proteins without Carbon Turnover throughout Life

PubMed Central

Lynnerup, Niels; Kjeldsen, Henrik; Heegaard, Steffen; Jacobsen, Christina; Heinemeier, Jan

2008-01-01

Background Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule) completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its 14C content from the atmospheric carbon dioxide. The 14C content of the lens proteins thus reflects the atmospheric content of 14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the 14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric 14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. Methodology/Principal Findings Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. Conclusions/Significance Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the 14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA). Potential targets may be nervous tissues in terms of senile or pre-senile degradation, as well as other highly

Time and Chronology: Conjoined Twins or Distant Cousins?

ERIC Educational Resources Information Center

Blow, Frances; Lee, Peter; Shemilt, Denis

2012-01-01

Weaknesses in pupils' grasp of historical chronology are a commonplace in popular discussion of the state of history education. However, as Blow, Lee and Shemilt argue, although undoubtedly necessary and fundamental, mastery of chronological conventions is not sufficient: the difficulties that pupils experience when learning history are…

BOMB STABILIZING STRUCTURE

DOEpatents

Kelley, J.L.; Runyan, C.E.

1963-12-10

A stabilizinig structure capable of minimizing deviations of a falling body such as a bomb from desired trajectory is described. The structure comprises a fin or shroud arrangement of double-wedge configuration, the feeding portion being of narrow wedge shape and the after portion being of a wider wedge shape. The structure provides a force component for keeping the body on essentially desired trajectory throughout its fall. (AEC)

1. EAST SIDE OF OVERHEAD BOMB TRANSPORT RACK, WITH BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. EAST SIDE OF OVERHEAD BOMB TRANSPORT RACK, WITH BUILDING 343 AT LEFT AND BUILDING 328 AT RIGHT. VIEW TO WEST. - Rocky Mountain Arsenal, Overhead Bomb Transport Rack, 1580 feet South of December Seventh Avenue; 860 feet West of D Street, Commerce City, Adams County, CO

The Holocene Minimum of the West Antarctic Ice Sheet: Radiocarbon Model Ages for Subglacial Sediments

NASA Astrophysics Data System (ADS)

Tulaczyk, S. M.; Stansell, N.; Scherer, R. P.; Powell, R. D.

2017-12-01

It is commonly assumed that the West Antarctic Ice Sheet (WAIS) is at the present time as small as it has been since at least the last interglacial period about 125,000 years ago. Yet, our recent analyses of subglacial sediments recovered from beneath the ice sheet indicate regionally widespread presence of radiocarbon. This unstable isotope with half life of 5,730 years should decay to nil if the analyzed subglacial sediment samples have been isolated beneath the ice sheet from the atmosphere and the ocean for 125,000 years (over 20 half lives). However, the apparent radiocarbon ages for these samples are in the range of about 20,000-30,000 years BP, based on radiocarbon Fraction Modern (FM) of a few to several percent. The apparent sediment ages cannot be taken at face value because: (1) they overlap with the Last Glacial Maximum (LGM) when WAIS is known to have extended over 1,000 km past the sediment sampling locations, and (2) Antarctic glacigenic sediments commonly contain significant admixture of old, radiocarbon-dead organic matter. The latter biases apparent radiocarbon ages because it violates the assumption that the initial radiocarbon fraction in a sample was equal to FM. To mitigate the problem with apparent ages, we assume that initial radiocarbon fraction in subglacial sediments was equal to that determined by us independently in J-9 sediments from beneath the Ross Ice Shelf (RIS) and calculate radiocarbon 'model ages' between 1,000 and 6,000 years BP. This period of time overlaps with a regional climatic optimum and with late phases of post-LGM glacioisostatic adjustment in the region (e.g., Kingslake et al., this session). We propose that the grounding line of WAIS, at least on the RIS side, retreated in mid/late Holocene more than 300 km beyond its current position and then re-advanced to reach its modern geometry. This implies that the main body of WAIS was significantly smaller than today in mid/late Holocene and that the ice sheet is capable of

The Oklahoma bombing. Lessons learned.

PubMed

Anteau, C M; Williams, L A

1997-06-01

The Oklahoma City bombing experience in April of 1995 provided a unique opportunity to test the effectiveness of an existing disaster plan. The critical care nurses at Columbia Presbyterian Hospital learned valuable lessons about managing intense activity, equipment and supplies, staffing resources, and visitor issues. The degree to which the bombing affected the emotional state of personnel was unanticipated, and leaders learned that critical stress management interventions should be included in every emergency preparedness plan. Additionally, recommendations include using runners for communication; assigning specific roles (supplies, staffing, triage); keeping additional staff in reserve for shift relief; ensuring ample hospital staff members are available to coordinate visitors and media; and setting up record systems to preserve continuity. The unique lessons learned as a result of this terrorist attack can be used by other critical care nurses to understand and refine disaster plans.

Psychiatric disorders in rescue workers after the Oklahoma City bombing.

PubMed

North, Carol S; Tivis, Laura; McMillen, J Curtis; Pfefferbaum, Betty; Spitznagel, Edward L; Cox, Jann; Nixon, Sara; Bunch, Kenneth P; Smith, Elizabeth M

2002-05-01

Psychiatric disorders were studied in a volunteer group of 181 firefighters who served as rescue/recovery workers after the Oklahoma City bombing. Approximately 34 months after the disaster, the authors retrospectively assessed psychopathology both before and after the bombing with the Diagnostic Interview Schedule. Findings for male rescue workers were compared with those of male primary victims who had been in the direct path of the blast and who had been assessed with the same instrument. The prevalence of posttraumatic stress disorder related to the bombing was significantly lower in male rescue workers (13%) than in male primary victims (23%). High rates of alcohol disorders (postdisaster: 24%; lifetime: 47%) were seen among all rescue workers, with virtually no new cases occurring after the bombing. The resilience seen in firefighters may be related to their career selection, their preparedness and experience, the fewer injuries they suffered, and postdisaster mental health interventions. However, alcohol disorders were endemic before the disaster, indicating a need for ongoing programs targeting this problem.

Air pollution taking an intercontinental express highway in a bomb

NASA Astrophysics Data System (ADS)

Stohl, A.; Huntrieser, H.; Richter, A.; Beirle, S.; Cooper, O.; Eckhardt, S.; Forster, C.; James, P.; Spichtinger, N.; Wagner, T.

2003-04-01

Intercontinental transport (ICT) of trace substances normally occurs on timescales ranging from a few days to several weeks. In this paper we present an extraordinary episode, where pollution transport from North America to Europe took only one day. The transport mechanism in this case was exceptional, as it involved an explosively generated cyclone, a so-called meteorological bomb. To our knowledge, this is the first study describing pollution transport in a bomb. The discovery of this event was based on transport model calculations and satellite measurements of NO_2, a species with a relatively short lifetime in the atmosphere, which could be transported that far only because of the high wind speeds produced by the bomb. Since about 50 bomb events per year occur in the Northern Hemisphere, most of them downstream of Asia and North America, there is possibly some climatological relevance of this transport mechanism for the global re-distribution of air pollution, particularly of short-lived species.

Physical Parameters of Vulcanian Eruptions at Pichincha Volcano, Ecuador: Bomb Morphologies and Textures

NASA Astrophysics Data System (ADS)

Wright, H. M.; Cashman, K.; Rosi, M.; Cioni, R.

2003-12-01

Vulcanian eruptions are common at many volcanoes around the world. These eruptions occur in energetic pulses and eject relatively small amounts of material. Each blast event (vulcanian eruption) has been inferred to represent a "throat-clearing" process that ejects a conduit plug. As such, we can examine the ejected material to reconstruct the conduit stratigraphy. The recent sequence of vulcanian eruptions at Guagua Pichincha volcano provides an opportunity to learn more about the dynamics of and pressurization conditions preceding vulcanian eruptions. From late 1999 - mid 2000, Pichincha experienced a series of vulcanian eruptions that ejected ballistic bombs, which now cover the surface of the crater. Bomb types range from dense to highly vesicular, with many exhibiting the breadcrusting that is ubiquitous in vulcanian deposits. Clast morphology varies with clast density, with slightly vesicular bombs having thick, glassy crusts and widely spaced cracks, whereas more vesicular bombs have thinner crusts and more closely spaced, regular crack patterns. The wide range of clast types appears to represent the stratigraphy of the conduit prior to each eruptive event, with denser blocks formed from more degassed magma near the top of the pre-eruptive conduit plug and more vesicular blocks representing deeper, less degassed levels in the conduit. This study uses the ballistic bombs, including the abundant breadcrust bombs, to learn more about conduit processes during a typical vulcanian eruption. In particular, we use the rapidly quenched crusts of breadcrust bombs, which preserve pre-eruptive conduit material, to determine gradients in volatile and crystal content in the conduit. The volatile content (both H2O and CO2) of the pre-eruptive melt was determined from FTIR spectroscopic analysis of bomb rind matrix glass. These values reach up to 1.2 wt% water and 10 ppm CO2, equivalent to 15 MPa maximum recorded presusure, or approximately 600 meters maximum depth

Summary findings of the fourth international radiocarbon intercomparison (FIRI)(1998-2001)

NASA Astrophysics Data System (ADS)

Boaretto, Elisabetta; Bryant, Charlotte; Carmi, Israel; Cook, Gordon; Gulliksen, Steinar; Harkness, Doug; Heinemeier, Jan; McClure, John; McGee, Edward; Naysmith, Philip; Possnert, Goran; Scott, Marian; van der Plicht, Hans; van Strydonck, Mark

2002-10-01

Interlaboratory comparisons have been widely used in applied radiocarbon science. These are an important part of ongoing quality assurance (QA) programmes, which are vital to the appropriate interpretation of the evidence provided by the 14C record in Quaternary applications (including climate change and environmental reconstruction). International comparisons of laboratory performance are an essential component of the quality assurance process in radiocarbon dating. If the user community is to have confidence in radiocarbon results, it needs to be assured that laboratories world wide are producing measurements that are reliable and in accordance with good practice. The findings from the most recent (completed in 2001) and extensive (more than 90 participating laboratories) radiocarbon intercomparison (FIRI) are reported here. This study was designed (i) to assess comparability, or otherwise, of the results from different laboratories and (ii) to quantify the extent and possible causes of any interlaboratory variation. The results demonstrate that there are no significant differences amongst the main measurement techniques (gas proportional counting, liquid scintillation counting and accelerator mass spectrometry (AMS)) but there is evidence of small laboratory offsets relative to known age samples for some laboratories. There is also evidence in some cases of underestimation of measurement precision. Approximately 10% of all results were classified as extreme (outliers) and these results were generated by 14% of the laboratories. Overall, the evidence supports the fact that radiocarbon laboratories are generally accurate and precise but that, notwithstanding internal QA procedures, some problems still occur, which can best be detected by participation in independent intercomparisons such as FIRI, where the results allow individual laboratories to assess their performance and to take remedial measures where necessary. The results from FIRI are significant in that

Epidemiological research on radiation-induced cancer in atomic bomb survivors.

PubMed

Ozasa, Kotaro

2016-08-01

The late effects of exposure to atomic bomb radiation on cancer occurrence have been evaluated by epidemiological studies on three cohorts: a cohort of atomic bomb survivors (Life Span Study; LSS), survivors exposed IN UTERO : , and children of atomic bomb survivors (F1). The risk of leukemia among the survivors increased remarkably in the early period after the bombings, especially among children. Increased risks of solid cancers have been evident since around 10 years after the bombings and are still present today. The LSS has clarified the dose-response relationships of radiation exposure and risk of various cancers, taking into account important risk modifiers such as sex, age at exposure, and attained age. Confounding by conventional risk factors including lifestyle differences is not considered substantial because people were non-selectively exposed to the atomic bomb radiation. Uncertainty in risk estimates at low-dose levels is thought to be derived from various sources, including different estimates of risk at background levels, uncertainty in dose estimates, residual confounding and interaction, strong risk factors, and exposure to residual radiation and/or medical radiation. The risk of cancer in subjects exposed IN UTERO : is similar to that in LSS subjects who were exposed in childhood. Regarding hereditary effects of radiation exposure, no increased risk of cancers associated with parental exposure to radiation have been observed in the F1 cohort to date. In addition to biological and pathogenetic interpretations of the present results, epidemiological investigations using advanced technology should be used to further analyze these cohorts. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

A Study of Correlation of Various Growth Indicators with Chronological Age.

PubMed

Singh, Sarabjeet; Sandhu, Navreet; Puri, Taruna; Gulati, Ritika; Kashyap, Rita

2015-01-01

The aim of this study was to assess the relationship of chronological age with cervical vertebrae skeletal maturation, frontal sinus width and antegonial notch depth and a correlation, if any, among the three variables. The samples were derived from lateral cephalometric radiographs of 80 subjects (40 males, 40 females; age range: 10 to 19 years). Cervical vertebral development was evaluated by the method of Hassel and Farman, frontal sinus width was measured by the method described by Ertürk and antegonial notch depth as described by Singer et al. The Pearson's correlation coefficients were estimated to assess the relationship of chronological age with cervical vertebrae skeletal maturation, frontal sinus width and antegonial notch depth. The Pearson's correlation coefficient were 0.855 (p < 0.001) between chronological age and cervical vertebrae skeletal maturation, and 0.333 (p < 0.001) between chronological age and frontal sinus width. A highly significant positive correlation was found between chronological age and cervical vertebrae skeletal maturation, and between chronological age and frontal sinus width. Nonsignificant correlation was found between chronological age and antegonial notch depth. How to cite this article: Singh S, Sandhu N, Puri T, Gulati R, Kashyap R. A Study of Correlation of Various Growth Indicators with Chronological Age. Int J Clin Pediatr Dent 2015;8(3): 190-195.

Radiocarbon ages and age models for the past 30,000 years in Bear Lake, Utah and Idaho

USGS Publications Warehouse

Colman, Steven M.; Rosenbaum, J.G.; Kaufman, D.S.; Dean, W.E.; McGeehin, J.P.

2009-01-01

Radiocarbon analyses of pollen, ostracodes, and total organic carbon (TOC) provide a reliable chronology for the sediments deposited in Bear Lake over the past 30,000 years. The differences in apparent age between TOC, pollen, and carbonate fractions are consistent and in accord with the origins of these fractions. Comparisons among different fractions indicate that pollen sample ages are the most reliable, at least for the past 15,000 years. The post-glacial radiocarbon data also agree with ages independently estimated from aspartic acid racemization in ostracodes. Ages in the red, siliclastic unit, inferred to be of last glacial age, appear to be several thousand years too old, probably because of a high proportion of reworked, refractory organic carbon in the pollen samples. Age-depth models for five piston cores and the Bear Lake drill core (BL00-1) were constructed by using two methods: quadratic equations and smooth cubic-splinefits. The two types of age models differ only in detail for individual cores, and each approach has its own advantages. Specific lithological horizons were dated in several cores and correlated among them, producing robust average ages for these horizons. The age of the correlated horizons in the red, siliclastic unit can be estimated from the age model for BL00-1, which is controlled by ages above and below the red, siliclastic unit. These ages were then transferred to the correlative horizons in the shorter piston cores, providing control for the sections of the age models in those cores in the red, siliclastic unit. These age models are the backbone for reconstructions of past environmental conditions in Bear Lake. In general, sedimentation rates in Bear Lake have been quite uniform, mostly between 0.3 and 0.8 mm yr-1 in the Holocene, and close to 0.5 mm yr-1 for the longer sedimentary record in the drill core from the deepest part of the lake. Copyright ?? 2009 The Geological Society of America.

Extraneous carbon assessment in ultra-microscale radiocarbon analysis using benzene polycarboxylic acids (BPCA)

NASA Astrophysics Data System (ADS)

Hanke, Ulrich M.; McIntyre, Cameron P.; Schmidt, Michael W. I.; Wacker, Lukas; Eglinton, Timothy I.

2016-04-01

Measurements of the natural abundance of radiocarbon (14C) concentrations in inorganic and organic carbon-containing materials can be used to investigate their date of origin. Particularly, the biogeochemical cycling of specific compounds in the environment may be investigated applying molecular marker analyses. However, the isolation of specific molecules from environmental matrices requires a complex processing procedure resulting in small sample sizes that often contain less than 30 μg C. Such small samples are sensitive to extraneous carbon (Cex) that is introduced during the purification of the compounds (Shah and Pearson, 2007). We present a thorough radiocarbon blank assessment for benzene polycarboxylic acids (BPCA), a proxy for combustion products that are formed during the oxidative degradation of condensed polyaromatic structures (Wiedemeier et al, in press). The extraneous carbon assessment includes reference material for (1) chemical extraction, (2) preparative liquid chromatography (3) wet chemical oxidation which are subsequently measured with gas ion source AMS (Accelerator Mass Spectrometer, 5-100 μg C). We always use pairs of reference materials, radiocarbon depleted (14Cfossil) and modern (14Cmodern) to determine the fraction modern (F14C) of Cex.Our results include detailed information about the quantification of Cex in radiocarbon molecular marker analysis using BPCA. Error propagation calculations indicate that ultra-microscale samples (20-30 μg) are feasible with uncertainties of less than 10 %. Calculations of the constant contamination reveal important information about the source (F14C) and mass (μg) of Cex (Wacker and Christl, 2011) for each sub procedure. An external correction of compound specific radiocarbon data is essential for robust results that allow for a high degree of confidence in the 14C results. References Shah and Pearson, 2007. Ultra-microscale (5-25μg C) analysis of individual lipids by 14C AMS: Assessment and

Radiocarbon dating of planktonic foraminifer shells: A cautionary tale

NASA Astrophysics Data System (ADS)

Mekik, Figen

2014-01-01

rate, bioturbation, winnowing, and calcite dissolution produce significant radiocarbon age offsets among multiple species of coexisting planktonic foraminifers and pteropod fragments. We compare the radiocarbon age of foraminifer species and pteropod fragments with estimates of percent calcite dissolved made with a sedimentary proxy (Globorotalia menardii fragmentation index—MFI) to delineate the effect of dissolution on radiocarbon age of foraminifers. Data from two core top transects on the Rio Grande Rise (RIO) and Ontong Java Plateau (OJP) and from down core sediments of varying sedimentation rates in the tropical Pacific (ME-27, MD98 2177, and MW91-9 56GGC) reveal that sediments with the greatest accumulation rates produce the least age offsets among coexisting species. Age offsets among coexisting foraminifers are about 3500 years on RIO, and 1000 years on OJP. Two core tops from RIO yield an age of the Last Glacial Maximum possibly due to mass displacement of younger sediments downslope. Foraminifer age increases with increasing dissolution and there is a consistent pattern of older foraminifer fragments coexisting with younger whole shells of the same species. The only exception is sediments which have experienced high dissolution where fragments are younger than whole shells. The age offset between fragments of G. menardii and its coexisting whole shells does not exceed the age offset among other coexisting foraminifer species in the same core tops.

The long-term outcome of atomic bomb survivors with gastric carcinoma.

PubMed

Yamamoto, Manabu; Matsuyama, Ayumi; Kameyama, Toshifumi; Okamoto, Masahiro; Okazaki, Jin; Utsunomiya, Tohru; Tsutsui, Shinichi; Ishida, Teruyoshi

2009-12-01

During the decade following the 1945 atomic bombing of Hiroshima, a high incidence of leukemia was observed among atomic bomb survivors. Subsequently, the incidence of other cancers gradually increased while that of leukemia decreased. We examined the long-term clinical outcome of gastric cancer and second primary cancer in atomic bomb survivors. Results of surgical treatment of gastric cancer were reviewed in 231 atomic bomb survivors and 759 control patients between 1995 and 2006. Long-term prognosis of gastric cancer in atomic bomb survivors was significantly poorer than that in control patients (P < 0.05). In a multivariate analysis, age, depth of tumor invasion, lymph node metastases, and curability were found to be significant and independent prognostic factors for gastric cancer. The incidence of second primary cancer after gastric cancer was significantly higher in survivors than in control patients (P < 0.01), because the number of elderly patients in the survivors was higher. Gastric cancer in survivors had a significantly poorer prognosis. Although the frequency of second primary cancer after gastric cancer in survivors was higher than that in control patients, it did not influence the prognosis.

Dealing with "The Bomb"

ERIC Educational Resources Information Center

Caruso, Nicholas D., Jr.

2004-01-01

Every superintendent eventually has to deal with "The Bomb." This refers to a loaded question from a board member dropped at an inopportune moment in a public meeting when the superintendent has been given no time to prepare an informed response. The superintendent's typical reactions include the "deer in the headlights" look, a big gulp or even a…

Prospects for Chronological Studies of Martian Rocks and Soils

NASA Technical Reports Server (NTRS)

Nyquist, L. E.; Shih, C-Y.; Reese, Y. D.

2008-01-01

Chronological information about Martian processes comes from two sources: Crater-frequency studies and laboratory studies of Martian meteorites. Each has limitations that could be overcome by studies of returned Martian rocks and soils. Chronology of Martian volcanism: The currently accepted chronology of Martian volcanic surfaces relies on crater counts for different Martian stratigraphic units [1]. However, there is a large inherent uncertainty for intermediate ages near 2 Ga ago. The effect of differing preferences for Martian cratering chronologies [1] is shown in Fig. 1. Stoeffler and Ryder [2] summarized lunar chronology, upon which Martian cratering chronology is based. Fig. 2 shows a curve fit to their data, and compares to it a corresponding lunar curve from [3]. The radiometric ages of some lunar and Martian meteorites as well as the crater-count delimiters for Martian epochs [4] also are shown for comparison to the craterfrequency curves. Scaling the Stoeffler-Ryder curve by a Mars/Moon factor of 1.55 [5] places Martian shergottite ages into the Early Amazonian to late Hesperian epochs, whereas using the lunar curve of [3] and a Mars/Moon factor 1 consigns the shergottites to the Middle-to-Late Amazonian, a less probable result. The problem is worsened if a continually decreasing cratering rate since 3 Ga ago is accepted [6]. We prefer the adjusted St ffler-Ryder curve because it gives better agreement with the meteorite ages (Fig.

Developmental assessment of preterm infants: Chronological or corrected age?

PubMed

Harel-Gadassi, Ayelet; Friedlander, Edwa; Yaari, Maya; Bar-Oz, Benjamin; Eventov-Friedman, Smadar; Mankuta, David; Yirmiya, Nurit

2018-06-12

The aim of this study is to examine the effect of age correction on the developmental assessment scores of preterm infants, using for the first time, the Mullen scales of early learning (MSEL) test. Participants included 110 preterm infants (born at a gestational age of ≤ 34 weeks) at ages 1, 4, 8, 12, 18, 24 and 36 months. The corrected age-based MSEL composite score and each of the five MSEL scale scores were significantly higher than chronological age-based scores at all ages. These corrected scores were significantly higher than the chronological scores regardless of gestational age whether weight was, or adequate or small for gestational age. Larger differences between corrected and chronological age-based scores significantly correlated with earlier gestational age and with lower birth weight between 1 and 24 months but not at 36 months. Using chronological age-based scores yielded significantly more infants identified with developmental delays than using corrected age-based scores. The findings indicate that clinicians and researchers, as well as family members, should be aware of and acknowledge the distinction between corrected and chronological ages when evaluating preterm infants in research and clinical practices. Copyright © 2018. Published by Elsevier Ltd.

RADIOCARBON ANALYSIS OF PM 2.5 AMBIENT AEROSOL

EPA Science Inventory

The radiocarbon (14C) content of an ambient aerosol sample can be directly related to the fraction of the sample's total carbon mass contributed by natural (biogenic) sources. Such knowledge is difficult to determine by other means, and important for devising ambient PM contro...

RADIOCARBON MEASUREMENTS ON PM-2.5 AMBIENT AEROSOL

EPA Science Inventory

Radiocarbon (14C) measurements provide an estimate of the fraction of carbon in a sample that is biogenic. The methodology has been extensively used in past wintertime studies to quantify the contribution of wood smoke to ambient aerosol. In summertime such measurements can p...

U. S. Military Documentary Films: A Chronological Analysis.

ERIC Educational Resources Information Center

Avery, Robert K.; Larson, Timothy L.

After presenting a chronological account of United States military documentary films from World War I through the Vietnam War, this paper reports on a study that compared the effectiveness of films prepared during World War II, the Korean War, and the Vietnam War. The first section, the chronological account, touches on such subjects as the…

Using radiocarbon to investigate soil respiration impacts on atmospheric CO2

NASA Astrophysics Data System (ADS)

Phillips, C. L.; LaFranchi, B. W.; McFarlane, K. J.; Desai, A. R.

2013-12-01

While soil respiration is believed to represent the largest single source of CO2 emissions on a global scale, there are few tools available to measure soil emissions at large spatial scales. We investigated whether radiocarbon (14C) abundance in CO2 could be used to detect and characterize soil emissions in the atmosphere, taking advantage of the fact that 14C abundance in soil carbon is elevated compared to the background atmosphere, a result of thermonuclear weapons testing during the mid-20th Century (i.e. bomb-C). Working in a temperate hardwood forest in Northern Wisconsin during 2011-12, we made semi-high-frequency measurements of CO2 at nested spatial scales from the soil subsurface to 150 m above ground level. These measurements were used to investigate seasonal patterns in respired C sources, and to evaluate whether variability in soil-respired Δ14C could also be detected in atmospheric measurements. In our ground-level measurements we found large seasonal variation in soil-respired 14CO2 that correlated with soil moisture, which was likely related to root activity. Atmospheric measurements of 14CO2 in the forest canopy (2 to 30m) were used to construct Keeling plots, and these provided larger spatial-scale estimates of respired 14CO2 that largely agreed with the soil-level measurements. In collaboration with the NOAA we also examined temporal patterns of 14CO2 at the Park Falls tall-tower (150m), and found elevated 14CO2 levels during summer months that likely resulted from increased respiration from heterotrophic sources. These results demonstrate that a fingerprint from soil-respired CO2 can be detected in the seasonal patterns of atmospheric 14CO2, even at a regionally-integrating spatial scale far from the soil surface.

Association of Acute Radiation Syndrome and Rain after the Bombings in Atomic Bomb Survivors.

PubMed

Ozasa, K; Sakata, R; Cullings, H M; Grant, E J

2016-06-01

Acute radiation-induced symptoms reported in survivors after the atomic bombings in Hiroshima and Nagasaki have been suspected to be associated with rain that fell after the explosions, but this association has not been evaluated in an epidemiological study that considers the effects of the direct dose from the atomic bombs and other factors. The aim of this study was to evaluate this association using information from a fixed cohort, comprised of 93,741 members of the Life Span Study who were in the city at the time of the bombing. Information on acute symptoms and exposure to rain was collected in surveys conducted by interviewers, primarily in the 1950s. The proportion of survivors developing severe epilation was around 60% at levels of direct radiation doses of 3 Gy or higher and less than 0.2% at levels <0.005 Gy regardless of reported rain exposure status. The low prevalence of acute symptoms at low direct doses indicates that the reported fallout rain was not homogeneously radioactive at a level sufficient to cause a substantial probability of acute symptoms. We observed that the proportion of reported acute symptoms was slightly higher among those who reported rain exposure in some subgroups, however, suggestions that rain was the cause of these reported symptoms are not supported by analyses specific to the known areas of radioactive fallout. Misclassification of exposure and outcome, including symptoms due to other causes and recall bias, appears to be a more plausible explanation. However, the insufficient and retrospective nature of the available data limited our ability to quantify the attribution to those possible causes.

Absenteeism among survivors of the atomic bombing of Hiroshima.

PubMed Central

Meigs, J W; Blot, W J; Inoue, S; Meigs, C R

1975-01-01

Atomic bomb survivors who worked at the Atomic Bomb Casualty Commission in Hiroshima during the years 1968-71 and held handbooks identifying them as survivors took significantly more days of both annual leave and sick leave than did matched and paired control subjects. These differences in leave-taking patterns are considered to be due to behavioural causes as they could not be attributed to radiation dose-response effects. PMID:1156567

The image of the atomic bomb in Japan before Hiroshima.

PubMed

Nakao, Maika

2009-01-01

This paper traces the roots of the image of the atomic bomb in Japan by investigating the various discourses on atomic energy and atomic weapons in Japanese literature prior to the bombing of Hiroshima in August 1945. Japan is a country that suffered an atomic attack and, at the same time, one of the countries that was engaged in atomic weapons research during the Second World War. During the war, the discourses on atomic weapons were not limited to the military or scientific communities, but included the general public, thus facilitating the creation of a shared image of the atomic bomb as an ultimate weapon. This paper examines how this image was created. This special issue deals with the comparison among different countries, but the purpose of my paper is to deepen this subject by illustrating the differences within a single country in different periods. This research aims to extend the historical perspective concerning the atomic bomb in Japan, and offers another way of looking at this both historical and contemporary issue.

Fallout isotope chronology of the near-surface sediment record of Lake Bolătău.

PubMed

Bihari, Árpád; Karlik, Máté; Mîndrescu, Marcel; Szalai, Zoltán; Grădinaru, Ionela; Kern, Zoltán

2018-01-01

Fallout isotope ( 210 Pb ex, 137 Cs and 241 Am) based dating has been carried out on the near-surface sediment core collected from Lake Bolătău-Feredeu (Bukovina, Romania). The motivation was to improve the chronology of this recent section in connection with significant fluctuations observed in sediment accumulation rates, particle size distribution and primordial radioisotope (i.e. 40 K and 232 Th) composition. Previously only an extrapolation of a broad-range OxCal age-depth model, which was based on 8 AMS radiocarbon dates from the deeper part of a parallel sediment sequence and tentatively validated for the upper part using the double peaks of the 137 Cs activity concentration distribution, was available for the studied section (1-24 cm). Parallel to the previous 137 Cs measurement, 210 Pb and 226 Ra (for a more detailed, 210 Pb ex -based chronology), 241 Am (for an additional time-marker), as well as 40 K and 232 Th concentrations have also been determined by gamma-spectrometry. In case of the 210 Pb ex -based chronology, due to a large deviation from a pure exponential distribution, the Constant Flux (CF) model has been used for the calculation of sediment ages and accumulation rates. Although the broad-range OxCal and the CF model were broadly similar down to 22 cm, the 210 Pb ex -based ages are clearly superior in terms of uncertainty in the uppermost 12 cm, while the broad-range model has smaller uncertainty below 20 cm (>150 years). The CF model gave an average mass accumulation rate of (0.08 ± 0.03) g cm -2 yr -1 for sections 0-11 cm, and (0.03 ± 0.01) g cm -2 yr -1 for sections 12-22 cm, respectively. Significant changes have been observed in the depth distribution of both the particle size distribution and the elemental/isotopic composition of the sediment record, most likely related to the variation observable in the intensity and volume of precipitation in the catchment. The obtained high-resolution records of Lake Bolătău, including

Marshall Space Flight Center 1990 annual chronology of events

NASA Technical Reports Server (NTRS)

Wright, Michael

1991-01-01

A chronological listing is provided of the major events for the Marshall Space Flight Center for the calendar year 1990. The MSFC Historian, Management Operations Office, compiled the chronology from various sources and from supplemental information provided by the major MSFC organizations.

Marshall Space Flight Center 1989 annual chronology of events

NASA Technical Reports Server (NTRS)

Wright, Michael

1990-01-01

A chronological listing of the major events for the Marshall Space Flight Center for the calendar year 1989 is provided. The MSFC Historian, Management Operations Office, compiled the chronology from various sources and from supplemental information provided by the major MSFC organizations.

Psychological response to the Oklahoma City bombing.

PubMed

Krug, R S; Nixon, S J; Vincent, R

1996-01-01

The bombing of the Alfred P. Murrah Federal Office Building in Oklahoma City was the most devastating terrorist activity that has occurred in America. Prevention of revictimization of persons seriously affected by the bombing was central to the planned response to this tragedy. Coordination and collaboration among local, state, and national agencies promoted effective clinical services provision, research facilitation, and prevention of revictimization. Information gathered from this cooperative effort will contribute to the effort to minimize the potential for such tragedies in the future as well as help to develop prevention and intervention strategies to reduce the effects when the next such disaster occurs.

Was Nazi Germany on the Road to an Atomic Bomb after all?

NASA Astrophysics Data System (ADS)

Lustig, Harry

2006-04-01

The story of Germany's efforts to develop a nuclear weapon during World War II is a much written about and contentious subject. However there has been agreement on one thing: by the end of the War the Germans had not achieved and were nowhere near to building a bomb. The dispute therefore has been about why Germany did not succeed. Now, from Germany, comes a challenge to this truth, in the provocative book Hitlers Bombe by Rainer Karlsch. The bombshell in Hitler's Bombe is the assertion that German scientists developed and tested a primitive fission and fusion nuclear weapon in March 1945. Karlsch bases this claim on testimony of witnesses in 1962, previously secret Russian documents, and the results of soil tests carried out in 2004 and 2005. However the physics is very murky and it seems out of the question that Germany had enough Uranium 235 or produced any Plutonium for a bomb. Hitlers Bombe also makes other, better documented and more credible revisionist assertions. These include the claim that the Nazis did continue to try to build a bomb after 1942 and that not Werner Heisenberg, but Kurt Diebner and Walther Gerlach were then the leaders of the German Uranium project. Karlsch's book therefore deserves more attention from physicists and historians than it has received in the United States.

Capturing total chronological and spatial uncertainties in palaeo-ice sheet reconstructions: the DATED example

NASA Astrophysics Data System (ADS)

Hughes, Anna; Gyllencreutz, Richard; Mangerud, Jan; Svendsen, John Inge

2017-04-01

Glacial geologists generate empirical reconstructions of former ice-sheet dynamics by combining evidence from the preserved record of glacial landforms (e.g. end moraines, lineations) and sediments with chronological evidence (mainly numerical dates derived predominantly from radiocarbon, exposure and luminescence techniques). However the geomorphological and sedimentological footprints and chronological data are both incomplete records in both space and time, and all have multiple types of uncertainty associated with them. To understand ice sheets' response to climate we need numerical models of ice-sheet dynamics based on physical principles. To test and/or constrain such models, empirical reconstructions of past ice sheets that capture and acknowledge all uncertainties are required. In 2005 we started a project (Database of the Eurasian Deglaciation, DATED) to produce an empirical reconstruction of the evolution of the last Eurasian ice sheets, (including the British-Irish, Scandinavian and Svalbard-Barents-Kara Seas ice sheets) that is fully documented, specified in time, and includes uncertainty estimates. Over 5000 dates relevant to constraining ice build-up and retreat were assessed for reliability and used together with published ice-sheet margin positions based on glacial geomorphology to reconstruct time-slice maps of the ice sheets' extent. The DATED maps show synchronous ice margins with maximum-minimum uncertainty bounds for every 1000 years between 25-10 kyr ago. In the first version of results (DATED-1; Hughes et al. 2016) all uncertainties (both quantitative and qualitative, e.g. precision and accuracy of numerical dates, correlation of moraines, stratigraphic interpretations) were combined based on our best glaciological-geological assessment and expressed in terms of distance as a 'fuzzy' margin. Large uncertainties (>100 km) exist; predominantly across marine sectors and other locations where there are spatial gaps in the dating record (e.g. the

Skeletal and chronological ages in American adolescents: current findings in skeletal maturation.

PubMed

Calfee, Ryan P; Sutter, Melanie; Steffen, Jennifer A; Goldfarb, Charles A

2010-10-01

This study was designed to assess the relationship between skeletal and chronological ages among current American adolescents using the Greulich and Pyle atlas for skeletal age determination. We used the Greulich and Pyle atlas to prospectively determine skeletal age in a group of 138 otherwise healthy American adolescents from 12 to 18 years of age. 62 males and 76 females were enrolled in this cohort. Paired Student t-tests were used to statistically compare the skeletal and chronological ages in this population. Subgroup analysis examined the effect of gender on differences between chronologic age and skeletal age. For the entire cohort, mean skeletal age was significantly greater than chronological age (mean 0.80 years, P < 0.01). In 29 cases (21%) the skeletal age was at least 2 years greater than the chronologic age. Among females, such cases with marked discrepancy occurred exclusively in those chronologically between 12 and 15 years of age (P < 0.01). Males demonstrated a 2-year or greater discrepancy more commonly than females (26 vs. 17%). In males, 2-year discrepancies were equally likely across chronologic ages (P = 0.82). Current American adolescents are significantly more mature by skeletal age, as determined by the Greulich and Pyle method, than their chronological age would suggest. The skeletal ages of females are most likely to markedly exceed chronologic age between the ages of 12-15 years.

The Last Act: The Atomic Bomb and the End of World War II.

ERIC Educational Resources Information Center

Smithsonian Institution, Washington, DC. National Air And Space Museum.

This text was to have been the script for the National Air and Space Museum's exhibition of the Enola Gay, focusing on the end of World War II and the decision of the United States to use of the atomic bomb. The Enola Gay was a B-29 aircraft that carried the atomic bomb dropped on Hiroshima, Japan, on August 6, 1945. The atomic bomb brought a…

The quest for an absolute chronology in human prehistory: anthropologists, chemists and the fluorine dating method in palaeoanthropology.

PubMed

Goodrum, Matthew R; Olson, Cora

2009-03-01

By the early twentieth century there was a growing need within palaeoanthropology and prehistoric archaeology to find a way of dating fossils and artefacts in order to know the age of specific specimens, but more importantly to establish an absolute chronology for human prehistory. The radiocarbon and potassium-argon dating methods revolutionized palaeoanthropology during the last half of the twentieth century. However, prior to the invention of these methods there were attempts to devise chemical means of dating fossil bone. Collaborations between Emile Rivière and Adolphe Carnot in the 1890s led to the development of the fluorine dating method, but it was not until the 1940s that this method was improved and widely implemented by Kenneth Oakley to resolve a number of problems in palaeoanthropology, including the Piltdown Man controversy. The invention of the fluorine dating method marked a significant advance in the quest for absolute dating in palaeoanthropology, but it also highlights interesting problems and issues relating to the ability of palaeoanthropologists and chemists to bring together different skills and bodies of knowledge in order successfully to develop and apply the fluorine dating method.

Exposure to Atomic Bomb Radiation and Age-Related Macular Degeneration in Later Life: The Hiroshima-Nagasaki Atomic Bomb Survivor Study.

PubMed

Itakura, Katsumasa; Takahashi, Ikuno; Nakashima, Eiji; Yanagi, Masahide; Kawasaki, Ryo; Neriishi, Kazuo; Wang, Jie Jin; Wong, Tien Yin; Hida, Ayumi; Ohishi, Waka; Kiuchi, Yoshiaki

2015-08-01

To investigate the association between radiation exposure from the atomic bombings and the prevalence of age-related macular degeneration (AMD) among older residents of Hiroshima and Nagasaki. The Adult Health Study is a cohort study of atomic bomb survivors living in Hiroshima and Nagasaki, comprising 2153 participants who underwent examinations with retinal fundus photographs in 2006-2008. The radiation dose to the eye for the analysis was estimated with the revised dosimetry system (DS02). The retinal photographs were graded according to the Wisconsin Age-Related Maculopathy Grading System modified for nonstereoscopic retinal images. Early and late AMD were defined according to the type of lesion detected in the worse eye of the participants. Person-specific data were analyzed by using a logistic regression model to assess the association between radiation dose and AMD. Among the 1824 subjects with gradable retinal images (84.7% of the overall participants), the estimated eye dose was widely distributed, with a mean of 0.45 Gy and standard deviation of 0.74 Gy. The prevalence of early and late AMD was 10.5% and 0.3%, respectively. There were no significant associations between radiation dose and AMD, with each 1-Gy increase in exposure, adjusted odds ratio was 0.93 (95% confidence interval [CI], 0.75-1.15) for early AMD and 0.79 (95% CI, 0.21-2.94) for late AMD. No significant associations were found between atomic bomb irradiation early in life and the prevalence of early or late AMD later in life among Japanese atomic bomb survivors.

The importance of radiocarbon dates and tephra for developing chronologies of Holocene environmental changes from lake sediments, North Far East

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lozhkin, Anatoly V.; Brown, Thomas A.; Anderson, Patricia M.

One problem with developing continuous chronologies of paleoenvironmental change in northern areas of the Far East using 14C is the low organic content in lake sediments. However, Holocene age-models can be supplemented by widespread tephra deposits reported in the Magadan region. The best documented of these tephras has been correlated to the KO tephra from southern Kamchatka dated to 7600 BP. Though a key chronostratigraphic marker, no detailed compendium of the distribution of this tephra and its associated 14C dates has been available from sites in the northern Far East. We provide such a summary. Known locally as the Elikchanmore » tephra, lake cores indicate an ash fall that extended ~1800 km north of the Kamchatkan caldera with a ~500 km wide trajectory in the Magadan region. Other Holocene tephras preserved in lake sediments have poorer age control and possibly date to ~2500 BP, ~2700 BP and ~6000 BP. These ashes seem to be restricted to coastal or near-coastal sites. Finally, a single record of a ~25,000 BP tephra has also been documented ~100 km to the northeast of Magadan.« less

The importance of radiocarbon dates and tephra for developing chronologies of Holocene environmental changes from lake sediments, North Far East

DOE PAGES

Lozhkin, Anatoly V.; Brown, Thomas A.; Anderson, Patricia M.; ...

2016-08-12

One problem with developing continuous chronologies of paleoenvironmental change in northern areas of the Far East using 14C is the low organic content in lake sediments. However, Holocene age-models can be supplemented by widespread tephra deposits reported in the Magadan region. The best documented of these tephras has been correlated to the KO tephra from southern Kamchatka dated to 7600 BP. Though a key chronostratigraphic marker, no detailed compendium of the distribution of this tephra and its associated 14C dates has been available from sites in the northern Far East. We provide such a summary. Known locally as the Elikchanmore » tephra, lake cores indicate an ash fall that extended ~1800 km north of the Kamchatkan caldera with a ~500 km wide trajectory in the Magadan region. Other Holocene tephras preserved in lake sediments have poorer age control and possibly date to ~2500 BP, ~2700 BP and ~6000 BP. These ashes seem to be restricted to coastal or near-coastal sites. Finally, a single record of a ~25,000 BP tephra has also been documented ~100 km to the northeast of Magadan.« less

Reassessment of the Upper Fremont Glacier Ice-Core Chronologies by Synchronizing of Ice-Core-Water Isotopes to a Nearby Tree-Ring Chronology.

PubMed

Chellman, Nathan; McConnell, Joseph R; Arienzo, Monica; Pederson, Gregory T; Aarons, Sarah M; Csank, Adam

2017-04-18

The Upper Fremont Glacier (UFG), Wyoming, is one of the few continental glaciers in the contiguous United States known to preserve environmental and climate records spanning recent centuries. A pair of ice cores taken from UFG have been studied extensively to document changes in climate and industrial pollution (most notably, mid-19th century increases in mercury pollution). Fundamental to these studies is the chronology used to map ice-core depth to age. Here, we present a revised chronology for the UFG ice cores based on new measurements and using a novel dating approach of synchronizing continuous water isotope measurements to a nearby tree-ring chronology. While consistent with the few unambiguous age controls underpinning the previous UFG chronologies, the new interpretation suggests a very different time scale for the UFG cores with changes of up to 80 years. Mercury increases previously associated with the mid-19th century Gold Rush now coincide with early-20th century industrial emissions, aligning the UFG record with other North American mercury records from ice and lake sediment cores. Additionally, new UFG records of industrial pollutants parallel changes documented in ice cores from southern Greenland, further validating the new UFG chronologies while documenting the extent of late 19th and early 20th century pollution in remote North America.

Reassessment of the Upper Fremont Glacier ice-core chronologies by synchronizing of ice-core-water isotopes to a nearby tree-ring chronology

USGS Publications Warehouse

Chellman, Nathan J.; McConnell, Joseph R.; Arienzo, Monica; Pederson, Gregory T.; Aarons, Sarah; Csank, Adam

2017-01-01

The Upper Fremont Glacier (UFG), Wyoming, is one of the few continental glaciers in the contiguous United States known to preserve environmental and climate records spanning recent centuries. A pair of ice cores taken from UFG have been studied extensively to document changes in climate and industrial pollution (most notably, mid-19th century increases in mercury pollution). Fundamental to these studies is the chronology used to map ice-core depth to age. Here, we present a revised chronology for the UFG ice cores based on new measurements and using a novel dating approach of synchronizing continuous water isotope measurements to a nearby tree-ring chronology. While consistent with the few unambiguous age controls underpinning the previous UFG chronologies, the new interpretation suggests a very different time scale for the UFG cores with changes of up to 80 years. Mercury increases previously associated with the mid-19th century Gold Rush now coincide with early-20th century industrial emissions, aligning the UFG record with other North American mercury records from ice and lake sediment cores. Additionally, new UFG records of industrial pollutants parallel changes documented in ice cores from southern Greenland, further validating the new UFG chronologies while documenting the extent of late 19th and early 20th century pollution in remote North America.

Simultaneous measurement of tritium and radiocarbon by ultra-low-background proportional counting.

PubMed

Mace, Emily; Aalseth, Craig; Alexander, Tom; Back, Henning; Day, Anthony; Hoppe, Eric; Keillor, Martin; Moran, Jim; Overman, Cory; Panisko, Mark; Seifert, Allen

2017-08-01

Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the beta decay spectra. We present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120mg of H 2 O and present sensitivity results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simultaneous measurement of tritium and radiocarbon by ultra-low-background proportional counting

DOE PAGES

Mace, Emily; Aalseth, Craig; Alexander, Tom; ...

2016-12-21

Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the beta decay spectra. In this paper, we present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120 mg of H 2O and present sensitivity results.

The recovery and analysis of mitochondrial DNA from exploded pipe bombs.

PubMed

Foran, David R; Gehring, Michael E; Stallworth, Shawn E

2009-01-01

Improvised explosive devices (IEDs) represent one of the most common modes of arbitrarily injuring or killing human beings. Because of the heat generated by, and destruction to, an IED postconflagration, most methods for identifying who assembled the device are ineffective. In the research presented, steel pipe bombs were mock-assembled by volunteers, and the bombs detonated under controlled conditions. The resultant shrapnel was collected and swabbed for residual cellular material. Mitochondrial DNA profiles were generated and compared blind to the pool of individuals who assembled the bombs. Assemblers were correctly identified 50% of the time, while another 19% could be placed into a group of three individuals with shared haplotypes. Only one bomb was assigned incorrectly. In some instances a contaminating profile (mixture) was also observed. Taken together, the results speak to the extreme sensitivity the methods have for identifying those who assemble IEDs, along with precautions needed when collecting and processing such evidence.

New Hydroxyproline Radiocarbon Dates from Sungir, Russia, Confirm Early Mid Upper Palaeolithic Burials in Eurasia

PubMed Central

Nalawade-Chavan, Shweta; McCullagh, James; Hedges, Robert

2014-01-01

Sungir (Russia) is a key Mid-Upper Palaeolithic site in Eurasia, containing several spectacular burials that disclose early evidence for complex burial rites in the form of a range of grave goods deposited along with the dead. Dating has been particularly challenging, with multiple radiocarbon dates ranging from 19,160±270 to 28,800±240 BP for burials that are believed to be closely similar in age. There are disparities in the radiocarbon dates of human bones, faunal remains and charcoal found on the floor of burials [1], [2], [3]. Our approach has been to develop compound-specific methods using High Performance Liquid Chromatography (HPLC) to separate single amino acids, such as hydroxyproline, and thereby avoid the known human contamination on the bones themselves. Previously, we applied this technique to obtain radiocarbon dates of ∼30,000 BP for Sungir 2, Sungir 3 and a mammoth bone from the occupation levels of the site [4]. The single amino acid radiocarbon dates were in good agreement with each other compared to all the dates previously reported, supporting their reliability. Here we report new hydroxyproline dates for two more human burials from the same site, Sungir 1 and Sungir 4. All five hydroxyproline dates reported are statistically indistinguishable and support an identical age for the group. The results suggest that compound-specific radiocarbon analysis should be considered seriously as the method of choice when precious archaeological remains are to be dated because they give a demonstrably contaminant-free radiocarbon age. The new ages are, together with the previously dated ‘Red Lady of Paviland’ human in the British Isles, the earliest for Mid Upper Palaeolithic burial behaviour in Eurasia, and point to the precocious appearance of this form of rite in Europe Russia. PMID:24416120

New hydroxyproline radiocarbon dates from Sungir, Russia, confirm early Mid Upper Palaeolithic burials in Eurasia.

PubMed

Nalawade-Chavan, Shweta; McCullagh, James; Hedges, Robert

2014-01-01

Sungir (Russia) is a key Mid-Upper Palaeolithic site in Eurasia, containing several spectacular burials that disclose early evidence for complex burial rites in the form of a range of grave goods deposited along with the dead. Dating has been particularly challenging, with multiple radiocarbon dates ranging from 19,160±270 to 28,800±240 BP for burials that are believed to be closely similar in age. There are disparities in the radiocarbon dates of human bones, faunal remains and charcoal found on the floor of burials. Our approach has been to develop compound-specific methods using High Performance Liquid Chromatography (HPLC) to separate single amino acids, such as hydroxyproline, and thereby avoid the known human contamination on the bones themselves. Previously, we applied this technique to obtain radiocarbon dates of ∼30,000 BP for Sungir 2, Sungir 3 and a mammoth bone from the occupation levels of the site. The single amino acid radiocarbon dates were in good agreement with each other compared to all the dates previously reported, supporting their reliability. Here we report new hydroxyproline dates for two more human burials from the same site, Sungir 1 and Sungir 4. All five hydroxyproline dates reported are statistically indistinguishable and support an identical age for the group. The results suggest that compound-specific radiocarbon analysis should be considered seriously as the method of choice when precious archaeological remains are to be dated because they give a demonstrably contaminant-free radiocarbon age. The new ages are, together with the previously dated 'Red Lady of Paviland' human in the British Isles, the earliest for Mid Upper Palaeolithic burial behaviour in Eurasia, and point to the precocious appearance of this form of rite in Europe Russia.

Chronology of KSC and KSC-related events for 1985

NASA Technical Reports Server (NTRS)

Nail, Ken, Jr.; Liston, Elaine

1986-01-01

A chronology of developments and events at the Kennedy Space Center (KSC) in 1985 documents the KSC role in NASA's progress. The chronology serves as a reference source for historians and other researchers. Arrangement is by day and month. Individual articles are attributed to published sources.

The impact of the 1995 Oklahoma City bombing on the partners of firefighters.

PubMed

Pfefferbaum, Betty; North, Carol S; Bunch, Kenneth; Wilson, Teddy G; Tucker, Phebe; Schorr, John K

2002-09-01

This study explored the impact of the 1995 Oklahoma City, Oklahoma, bombing on the spouses and significant others of a volunteer sample of Oklahoma City firefighters who participated in the bombing rescue effort. Twenty-seven partners of Oklahoma City firefighters participated in this study, conducted 42 to 44 months after the bombing. These partners were assessed using a structured diagnostic interview and a companion interview to examine exposure, rates of psychiatric disorders and symptoms, functioning, health, and relationships. Coping and perception of the firefighter partner's response were also examined. Some of the women were exposed directly; most knew someone who had been involved in the disaster, and all reported exposure through the media. The rate of psychiatric disorders in the women following the disaster was 22%, essentially unchanged from before the incident. One developed bomb-related posttraumatic stress disorder (PTSD). Most were satisfied with their work performance; 15% reported that their health had worsened since the bombing, and more than one third reported permanent changes in relationships as a result of the bombing. Most coped by turning to friends or relatives, with less than 10% seeking professional help. Many described symptoms in their firefighter mate; all reported that their mate had been affected by the experience, and one half said their mate had fully recovered. The mates of these firefighters fared relatively well in terms of psychiatric disorders, symptoms, and ability to function. The prevalence of bomb-related posttraumatic stress disorder was considerably lower in this sample than in samples of individuals more directly exposed to the bombing, although some reported changes in relationships and health. The results suggest the need for further study of the impact of interpersonal exposure in those who provide support for rescue-and-recovery workers in major terrorist incidents.

Correlation among chronologic age, skeletal maturity, and dental age.

PubMed

Sukhia, Rashna H; Fida, Mubassar

2010-01-01

To determine the correlation among chronologic age, skeletal maturity, and dental age in reference to both sexes. In 380 subjects (147 males and 233 females) between 7 and 17 years of age, skeletal maturity was assessed using the cervical vertebral maturation stages described by Baccetti et al. Dental age was determined using the Demirjian method. The correlation between skeletal maturity and chronologic age on one side and between skeletal maturity and dental age on the other was assessed with Spearman rank correlation coefficients. Pearson correlation coefficients were used to assess the correlation between chronologic and dental age. For both sexes, significant correlations among chronologic age, skeletal maturity, and dental age were found. The mandibular first premolar had the highest correlation with skeletal maturation in both sexes. As skeletal maturity and dental age are significantly correlated, tooth development may be used to assess a patient's skeletal maturity at an early age. © 2011 BY QUINTESSENCE PUBLISHING CO, INC.

Bomb Threat Assessments. Fact Sheet

ERIC Educational Resources Information Center

Tunkel, Ronald F.

2010-01-01

This information provides a brief, summary outline of how investigators should assess anonymous bomb threats at schools. Applying these principles may help administrators and law enforcement personnel accurately assess the viability and credibility of a threat and appropriately gauge their response. Any credible evidence provided by teachers or…

An analysis of carbon and radiocarbon profiles across a range ecosystems types

NASA Astrophysics Data System (ADS)

Heckman, K. A.; Gallo, A.; Hatten, J. A.; Swanston, C.; Strahm, B. D.; Sanclements, M.

2016-12-01

Soil carbon stocks have become recognized as increasingly important in the context of climate change and global C cycle modeling. As modelers seek to identify key parameters affecting the size and stability of belowground C stocks, attention has been drawn to the mineral matrix and the soil physiochemical factors influenced by it. Though clay content has often been utilized as a convenient and key explanatory variable for soil C dynamics, its utility has recently come under scrutiny as new paradigms of soil organic matter stabilization have been developed. We utilized soil cores from a range of National Ecological Observatory Network (NEON) experimental plots to examine the influence of mineralogical parameters on soil C stocks and turnover and their relative importance in comparison to climatic variables. Results are presented for a total of 11 NEON sites, spanning Alfisols, Entisols, Mollisols and Spodosols. Soils were sampled by genetic horizon, density separated according to density fractionation: light fractions (particulate organics neither occluded within aggregates nor associated with mineral surfaces), occluded fractions (particulate organics occluded within aggregates), and heavy fractions (organics associated with mineral surfaces). Bulk soils and density fractions were measured for % C and radiocarbon abundance (as a measure of C stability). Carbon and radiocarbon abundances were examined among fractions and in the context of climatic variables (temperature, precipitation, elevation) and soil physiochemical variables (% clay and pH). No direct relationships between temperature and soil C or radiocarbon abundances were found. As a whole, soil radiocarbon abundance in density fractions decreased in the order of light>heavy>occluded, highlighting the importance of both surface sorption and aggregation to the preservation of organics. Radiocarbon concentrations of the heavy fraction (mineral adsorbed) were significantly, though weakly, correlated with pH (r

RADIOCARBON MEASUREMENT OF THE BIOGENIC CONTRIBUTION TO SUMMERTIME PM 2.5 AMBIENT AEROSOL IN NASHVILLE, TN

EPA Science Inventory

Radiocarbon (14C) measurements performed on PM-2.5 samples collected near Nashville, TN from June 21 to July 13, 1999, showed high levels of modern carbon, ranging from 56 to 80% of the total carbon in the samples. Radiocarbon measurements performed on dichloromethane extracts of...

Outcome and status of microsatellite stability in Japanese atomic bomb survivors with early gastric carcinoma.

PubMed

Yamamoto, Manabu; Taguchi, Kenichi; Yamanaka, Takeharu; Matsuyama, Ayumi; Yoshinaga, Keiji; Tsutsui, Shinichi; Ishida, Teruyoshi

2013-03-01

In the decade after the 1945 atomic bombing of Hiroshima, a high incidence of leukemia was observed among atomic bomb survivors. However, the incidence of other cancers gradually increased, while that of leukemia decreased after this period. We evaluated the clinical outcome of early gastric cancer and microsatellite stability over a long-term period in atomic bomb survivors. The results of surgical treatment for early gastric cancer were reviewed for 117 atomic bomb survivors and 394 control patients between 1995 and 2006. In addition, immunohistochemical staining for hMSH2 and hMLH1 expression was performed to evaluate the status of microsatellite stability in 57 atomic bomb survivors and 82 control patients. The long-term survival rate for early gastric cancer in atomic bomb survivors was significantly lower than that in control patients (p < 0.01). Multivariable analysis revealed that age and sex were significant and independent prognostic factors for early gastric cancer. Defective hMSH2 and/or hMLH1 expression was also significantly higher in survivors than in control patients (p < 0.001). Logistic regression analysis revealed that atomic bomb survivorship was related to defective hMSH2 and/or hMLH1 expression. The prognosis of early gastric cancer in atomic bomb survivors was poor and was related to age and sex, rather than to being an atomic bomb survivor. Furthermore, a higher rate of defective hMSH2 and/or hMLH1 expression was observed in the survivors.

Personality and Major Depression among Directly Exposed Survivors of the Oklahoma City Bombing

PubMed Central

North, Carol S.; Cloninger, C. Robert

2012-01-01

Background. Few disaster studies have specifically examined personality and resilience in association with disaster exposure, posttraumatic stress disorder (PTSD), and major depression. Methods. 151 directly-exposed survivors of the Oklahoma City bombing randomly selected from a bombing survivor registry completed PTSD, major depression, and personality assessments using the Diagnostic Interview Schedule for DSM-IV and the Temperament and Character Inventory, respectively. Results. The most prevalent postdisaster psychiatric disorder was bombing-related PTSD (32%); major depression was second in prevalence (21%). Bombing-related PTSD was associated with the combination of low self-directedness and low cooperativeness and also with high self-transcendence and high harm avoidance in most configurations. Postdisaster major depression was significantly more prevalent among those with (56%) than without (5%) bombing-related PTSD (P < .001) and those with (72%) than without (14%) predisaster major depression (P < .001). Incident major depression was not associated with the combination of low self-directedness and low cooperativeness. Conclusions. Personality features can distinguish resilience to a specific life-threatening stressor from general indicators of well-being. Unlike bombing-related PTSD, major depression was not a robust marker of low resilience. Development and validation of measures of resilience should utilize well-defined diagnoses whenever possible, rather than relying on nonspecific measures of psychological distress. PMID:23008763

Personality and Major Depression among Directly Exposed Survivors of the Oklahoma City Bombing.

PubMed

North, Carol S; Cloninger, C Robert

2012-01-01

Background. Few disaster studies have specifically examined personality and resilience in association with disaster exposure, posttraumatic stress disorder (PTSD), and major depression. Methods. 151 directly-exposed survivors of the Oklahoma City bombing randomly selected from a bombing survivor registry completed PTSD, major depression, and personality assessments using the Diagnostic Interview Schedule for DSM-IV and the Temperament and Character Inventory, respectively. Results. The most prevalent postdisaster psychiatric disorder was bombing-related PTSD (32%); major depression was second in prevalence (21%). Bombing-related PTSD was associated with the combination of low self-directedness and low cooperativeness and also with high self-transcendence and high harm avoidance in most configurations. Postdisaster major depression was significantly more prevalent among those with (56%) than without (5%) bombing-related PTSD (P < .001) and those with (72%) than without (14%) predisaster major depression (P < .001). Incident major depression was not associated with the combination of low self-directedness and low cooperativeness. Conclusions. Personality features can distinguish resilience to a specific life-threatening stressor from general indicators of well-being. Unlike bombing-related PTSD, major depression was not a robust marker of low resilience. Development and validation of measures of resilience should utilize well-defined diagnoses whenever possible, rather than relying on nonspecific measures of psychological distress.

Challenging process to make the Lateglacial tree-ring chronologies from Europe absolute - an inventory

NASA Astrophysics Data System (ADS)

Kaiser, Klaus Felix; Friedrich, Michael; Miramont, Cécile; Kromer, Bernd; Sgier, Mario; Schaub, Matthias; Boeren, Ilse; Remmele, Sabine; Talamo, Sahra; Guibal, Frédéric; Sivan, Olivier

2012-03-01

Here we present the entire range of Lateglacial tree-ring chronologies from Switzerland, Germany, France, covering the Lateglacial north and west of the Alps without interruption as well as finds from northern Italy, complemented by a 14C data set of the Swiss chronologies. Geographical expansion of cross-matched European Lateglacial chronologies, limits and prospects of teleconnection between remote sites and extension of the absolute tree-ring chronology are discussed. High frequency signals and long-term fluctuations are revealed by the ring-width data sets of the newly constructed Swiss Late-glacial Master Chronology (SWILM) as well as the Central European Lateglacial Master Chronology (CELM) spanning 1606 years. They agree well with the characteristics of Boelling/Alleroed (GI-1) and the transition into Younger Dryas (GS-1). The regional chronologies of Central Europe may provide improved interconnection to other terrestrial or marine high-resolution archives. Nevertheless the breakthrough to a continuous absolute chronology back to Boelling (GI-1e) has not yet been achieved. A gap remains, even though it is covered by several floating chronologies from France and Switzerland.

Radiation exposure and disease questionnaires of early entrants after the Hiroshima bombing.

PubMed

Imanaka, Tetsuji; Endo, Satoru; Kawano, Noriyuki; Tanaka, Kenichi

2012-03-01

It is popularly known that people who entered into the ground-zero area shortly after the atomic bombings in Hiroshima and Nagasaki suffered from various syndromes similar to acute radiation effects. External exposures from neutron-induced radionuclides in soil have recently been reassessed based on DS02 calculations as functions of both distance from the hypocentres and elapsed time after the explosions. Significant exposure due to induced radiation can be determined for those who entered the area within 1000 m from the hypocentres shortly after the bombing. Although it was impossible to track the action of each of the survivors over the days or weeks following the bombings in order to make reliable dose estimates for their exposures to soil activation or fallout, four individuals among those early entrants were investigated here to describe useful information of what happened shortly after the bombing.

The course of post-traumatic stress disorder after the Oklahoma City bombing.

PubMed

North, C S

2001-12-01

Oklahoma City bombing survivors (N = 182) were studied 6 months post-bombing and reassessed approximately 1 year later (N = 141) to determine the longitudinal course of post-traumatic stress disorder (PTSD) and other psychiatric disorders. The Diagnostic Interview Schedule assessed lifetime, current, predisaster, and post-bombing psychiatric diagnoses at both assessment points. One-third of the Oklahoma City bombing survivors had PTSD at index, and similar rates were diagnosed at follow-up. More recovery from depression was apparent than from PTSD. No delayed onset PTSD was observed, and all PTSD was chronic. Avoidance and numbing symptoms were dominant in defining the development of PTSD. Early onset and chronicity of PTSD indicate need for prompt and long-term intervention after disasters. Focus on avoidance and numbing symptoms may aid in identification of individuals needing intervention and monitoring the course of PTSD.

Casualties in civilians and coalition soldiers from suicide bombings in Iraq, 2003-10: a descriptive study.

PubMed

Hicks, Madelyn Hsiao-Rei; Dardagan, Hamit; Bagnall, Peter M; Spagat, Michael; Sloboda, John A

2011-09-03

Suicide bombs in Iraq are a major public health problem. We aimed to describe documented casualties from suicide bombs in Iraq during 2003-10 in Iraqi civilians and coalition soldiers. In this descriptive study, we analysed and compared suicide bomb casualties in Iraq that were documented in two datasets covering March 20, 2003, to Dec 31, 2010--one reporting coalition-soldier deaths from suicide bombs, the other reporting deaths and injuries of Iraqi civilians from armed violence. We analysed deaths and injuries over time, by bomb subtype and victim demographics. In 2003-10, 1003 documented suicide bomb events caused 19% (42,928 of 225,789) of all Iraqi civilian casualties in our dataset, 26% (30,644 of 117,165) of injured civilians, and 11% (12,284 of 108,624) of civilian deaths. The injured-to-killed ratio for civilians was 2·5 people injured to one person killed from suicide bombs. Suicide bombers on foot caused 43% (5314 of 12,284) of documented suicide bomb deaths. Suicide bombers who used cars caused 40% (12,224 of 30,644) of civilian injuries. Of 3963 demographically identifiable suicide bomb fatalities, 2981 (75%) were men, 428 (11%) were women, and 554 (14%) were children. Children made up a higher proportion of demographically identifiable deaths from suicide bombings than from general armed violence (9%, 3669 of 40,276 deaths; p<0·0001). The injured-to-killed ratio for all suicide bombings was slightly higher for women than it was for men (p=0·02), but the ratio for children was lower than it was for both women (p<0·0001) and men (p=0·0002). 200 coalition soldiers were killed in 79 suicide bomb events during 2003-10. More Iraqi civilians per lethal event were killed than were coalition soldiers (12 vs 3; p=0·004). Suicide bombers in Iraq kill significantly more Iraqi civilians than coalition soldiers. Among civilians, children are more likely to die than adults when injured by suicide bombs. None. Copyright © 2011 Elsevier Ltd. All rights

Effects of radiation on the incidence of prostate cancer among Nagasaki atomic bomb survivors.

PubMed

Kondo, Hisayoshi; Soda, Midori; Mine, Mariko; Yokota, Kenichi

2013-10-01

Atomic bomb survivors have been reported to have an increased risk of some cancers, especially leukemia. However, the risk of prostate cancer in atomic bomb survivors is not known to have been examined previously. This study examined the association between atomic bomb radiation and the incidence of prostate cancer among male Nagasaki atomic bomb survivors. The subjects were classified by distance from the hypocenter into a proximal group (<2 km), a distal group (≥2 km), and an early entrance group (those who entered the region <2 km from the hypocenter within 2 weeks after the explosion). Between 1996 and 2009, 631 new cases of prostate cancer were identified among approximately 18 400 male Nagasaki atomic bomb survivors who were alive in 1996. The Cox proportional hazard model was used to estimate the risk of prostate cancer development, with adjustment for age at atomic bomb explosion, attained age, smoking status, and alcohol consumption. Compared with the distal group, the proximal group had significant increased risks of total, localized, and high-grade prostate cancer (relative risk and 95% confidence interval: 1.51 [1.21-1.89]; 1.80 [1.26-2.57]; and 1.88 [1.20-2.94], respectively). This report is the first known to reveal a significant relationship between atomic bomb radiation and prostate cancer. © 2013 Japanese Cancer Association.

Suicide in paradise: aftermath of the Bali bombings.

PubMed

Suryani, L K; Page, A; Lesmana, C B J; Jennaway, M; Basudewa, I D G; Taylor, R

2009-08-01

The relationship between the Bali (Indonesia) bombings of October 2002 and suicide has not previously been investigated, despite anecdotal evidence of the economic and psychological consequences of these attacks. Suicide rates were calculated over the period 1994-2006 in three Bali regencies to determine whether suicide increased in the period following the first Bali bombings. Poisson regression and time-series models were used to assess the change in suicide rates by sex, age and area in the periods before and after October 2002. Suicide rates (age-adjusted) increased in males from an average of 2.84 (per 100 000) in the period pre-2002 to 8.10 in the period post-2002, and for females from 1.51 to 3.68. The greatest increases in suicide in the post-2002 period were in the age groups 20-29 and 60 years, for both males and females. Tourist arrivals fell significantly after the bombings, and addition of tourism to models reduced relative risk estimates of suicide, suggesting that some of the increase may be attributable to the socio-economic effects of declines in tourism. There was an almost fourfold increase in male suicide risk and a threefold increase in female suicide risk in the period following the 2002 bombings in Bali. Trends in tourism did not account for most of the observed increases. Other factors such as indirect socio-economic effects and Balinese notions of collective guilt and anxieties relating to ritual neglect are important in understanding the rise in suicide in the post-2002 period.

Resampling soil profiles can constrain large-scale changes in the C cycle: obtaining robust information from radiocarbon measurements

NASA Astrophysics Data System (ADS)

Baisden, W. T.; Prior, C.; Lambie, S.; Tate, K.; Bruhn, F.; Parfitt, R.; Schipper, L.; Wilde, R. H.; Ross, C.

2006-12-01

, 1 kg C m-2 or more may be reactive on decadal timescales, supporting evidence of soil C losses from throughout the soil profiles. Information from resampled soil profiles can be combined with additional contemporary measurements to test hypotheses about mechanisms for soil C changes. For example, Δ14C in excess of 200‰ in water extractable dissolved organic C (DOC) from surface soil horizons supports the hypothesis that decadal movement of DOC represents an important translocation of soil C. These preliminary results demonstrate that resampling whole soil profiles can support substantial progress in C cycle science, ranging from updating operational C accounting systems to the frontiers of research. Resampling can be complementary or superior to fixed-depth interval sampling of surface soil layers. Resampling must however be undertaken with relative urgency to maximize the potential interpretive power of bomb-derived radiocarbon.

Speleothem chronology with sub-annual resolution in a near-entrance cave setting using oxygen isotope and trace element records

NASA Astrophysics Data System (ADS)

Carlson, P. E.; Miller, N. R.; Banner, J.; Breecker, D.

2016-12-01

Speleothems that grow in well-ventilated zones of caves are typically avoided when selecting specimens for paleoclimate reconstruction, due to concerns about evaporation and kinetic isotope effects. Near-entrance cave environments are characterized by near-ambient CO2 concentrations year-round and are influenced by surface temperature fluctuations. At Westcave Preserve (Westcave), a shallow, well-ventilated cave in central Texas, we have found seasonal temperature differences recorded in both the oxygen isotope and trace element compositions of speleothem calcite. The seasonal nature of these records has been confirmed by monitoring the chemical composition of drip water and substrate calcite since 2009 (Feng et al., 2014; Casteel and Banner, 2015). We present an ultrahigh-resolution (weekly to monthly) record of δ18O, Mg, Sr, and Ba in Westcave stalagmite WC-3, as well as monthly measurements of drip water geochemistry. We find drip water δ18O and [Mg] are essentially invariant, while seasonal variations in stalagmite calcite δ18O and Mg compositions are in good agreement with predicted temperature-dependent fractionation between water and calcite. Both drip water and speleothem calcite Sr and Ba vary seasonally, which we hypothesize is due to seasonal changes in moisture conditions in the epikarst. We use each of these annual geochemical cycles as independent chronological controls in order to develop a single age model for the stalagmite. These independent chronological counts are consistent with each other, and with 14C bomb-peak and U-series evidence. We argue that the potential for this kind of multi-proxy, seasonally-resolved dating in near-entrance stalagmites makes them especially valuable paleoclimate archives that should not be ignored in speleothem studies.

Deconstructing The Bomb: Confessions of a Nuclear Archeologist

NASA Astrophysics Data System (ADS)

Coster-Mullen, John

2017-01-01

I am the author of the groundbreaking book Atom Bombs: The Top Secret Inside Story of Little Boy and Fat Man. I will be sharing some of my quarter century of research and methodology that has allowed me to be the first researcher ever to unravel with an unprecedented level of accuracy, the most closely-guarded secrets of the first two Atomic Bombs (``Little Boy'' and ``Fat Man'') created by the Manhattan Project that were used to end WWII. I refer to this methodology as ``Nuclear Archeology'' and will demonstrate that this was done using entirely ``Open Sources'' of information.

The use of the terrestrial snails of the genera Megalobulimus and Thaumastus as representatives of the atmospheric carbon reservoir

NASA Astrophysics Data System (ADS)

Macario, Kita D.; Alves, Eduardo Q.; Carvalho, Carla; Oliveira, Fabiana M.; Ramsey, Christopher Bronk; Chivall, David; Souza, Rosa; Simone, Luiz Ricardo L.; Cavallari, Daniel C.

2016-06-01

In Brazilian archaeological shellmounds, many species of land snails are found abundantly distributed throughout the occupational layers, forming a contextualized set of samples within the sites and offering a potential alternative to the use of charcoal for radiocarbon dating analyses. In order to confirm the effectiveness of this alternative, one needs to prove that the mollusk shells reflect the atmospheric carbon isotopic concentration in the same way charcoal does. In this study, 18 terrestrial mollusk shells with known collection dates from 1948 to 2004 AD, around the nuclear bombs period, were radiocarbon dated. The obtained dates fit the SH1-2 bomb curve within less than 15 years range, showing that certain species from the Thaumastus and Megalobulimus genera are reliable representatives of the atmospheric carbon isotopic ratio and can, therefore, be used to date archaeological sites in South America.

The use of the terrestrial snails of the genera Megalobulimus and Thaumastus as representatives of the atmospheric carbon reservoir

PubMed Central

Macario, Kita D.; Alves, Eduardo Q.; Carvalho, Carla; Oliveira, Fabiana M.; Ramsey, Christopher Bronk; Chivall, David; Souza, Rosa; Simone, Luiz Ricardo L.; Cavallari, Daniel C.

2016-01-01

In Brazilian archaeological shellmounds, many species of land snails are found abundantly distributed throughout the occupational layers, forming a contextualized set of samples within the sites and offering a potential alternative to the use of charcoal for radiocarbon dating analyses. In order to confirm the effectiveness of this alternative, one needs to prove that the mollusk shells reflect the atmospheric carbon isotopic concentration in the same way charcoal does. In this study, 18 terrestrial mollusk shells with known collection dates from 1948 to 2004 AD, around the nuclear bombs period, were radiocarbon dated. The obtained dates fit the SH1-2 bomb curve within less than 15 years range, showing that certain species from the Thaumastus and Megalobulimus genera are reliable representatives of the atmospheric carbon isotopic ratio and can, therefore, be used to date archaeological sites in South America. PMID:27271349

Revised age of deglaciation of Lake Emma based on new radiocarbon and macrofossil analyses

USGS Publications Warehouse

Elias, S.A.; Carrara, P.E.; Toolin, L.J.; Jull, A.J.T.

1991-01-01

Previous radiocarbon ages of detrital moss fragments in basal organic sediments of Lake Emma indicated that extensive deglaciation of the San Juan Mountains occurred prior to 14,900 yr B.P. (Carrara et al., 1984). Paleoecological analyses of insect and plant macrofossils from these basal sediments cast doubt on the reliability of the radiocarbon ages. Subsequent accelerator radiocarbon dates of insect fossils and wood fragments indicate an early Holocene age, rather than a late Pleistocene age, for the basal sediments of Lake Emma. These new radiocarbon ages suggest that by at least 10,000 yr B.P. deglaciation of the San Juan Mountains was complete. The insect and plant macrofossils from the basal organic sediments indicate a higher-than-present treeline during the early Holocene. The insect assemblages consisted of about 30% bark beetles, which contrasts markedly with the composition of insects from modern lake sediments and modern specimens collected in the Lake Emma cirque, in which bark beetles comprise only about 3% of the assemblages. In addition, in the fossil assemblages there were a number of flightless insect species (not subject to upslope transport by wind) indicative of coniferous forest environments. These insects were likewise absent in the modern assemblage. ?? 1991.

Radiocarbon as a Novel Tracer of Extra-Antarctic Feeding in Southern Hemisphere Humpback Whales.

PubMed

Eisenmann, Pascale; Fry, Brian; Mazumder, Debashish; Jacobsen, Geraldine; Holyoake, Carlysle Sian; Coughran, Douglas; Bengtson Nash, Susan

2017-06-29

Bulk stable isotope analysis provides information regarding food web interactions, and has been applied to several cetacean species for the study of migration ecology. One limitation in bulk stable isotope analysis arises when a species, such as Southern hemisphere humpback whales, utilises geographically distinct food webs with differing isotopic baselines. Migrations to areas with different baselines can result in isotopic changes that mimic changes in feeding relations, leading to ambiguous food web interpretations. Here, we demonstrate the novel application of radiocarbon measurement for the resolution of such ambiguities. Radiocarbon was measured in baleen plates from humpback whales stranded in Australia between 2007 and 2013, and in skin samples collected in Australia and Antarctica from stranded and free-ranging animals. Radiocarbon measurements showed lower values for Southern Ocean feeding than for extra-Antarctic feeding in Australian waters. While the whales mostly relied on Antarctic-derived energy stores during their annual migration, there was some evidence of feeding within temperate zone waters in some individuals. This work, to our knowledge, provides the first definitive biochemical evidence for supplementary feeding by southern hemisphere humpback whales within temperate waters during migration. Further, the work contributes a powerful new tool (radiocarbon) for tracing source regions and geographical feeding.

Radiocarbon Depression in Aquatic Foodwebs of the Colorado River, USA: Coupling Between Carbonate Weathering and the Biosphere

NASA Astrophysics Data System (ADS)

Sickman, J. O.; Huang, W.; Lucero, D.; Anderson, M.

2012-12-01

The 14C isotopic composition of living organisms is generally considered to be in isotopic equilibrium with atmosphere CO2. During the course of investigations of aquatic foodwebs of the Colorado River, we measured substantial radiocarbon depression of organisms within planktonic and benthic foodwebs of Copper Basin Reservoir, a short residence-time water body at the intake to the Colorado River Aqueduct. All trophic levels had depressed radiocarbon content with inferred "age" of ca. 1,200 radiocarbon years (range: 0.85 to 0.87 fraction modern carbon (fmc)). Additional measurements of the radiocarbon content of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were made in other major rivers in California (New (near Salton Sea), Santa Ana (near Riverside), San Joaquin (near Fresno) and Salinas (near San Luis Obispo)). In the New River (which is composed primarily of irrigation tailwater derived from the Colorado River), the radiocarbon values for DIC closely matched those found in biota of the Copper Basin Reservoir (0.85 to 0.87 fmc), but radiocarbon values for DOC were slightly higher (0.91 to 0.95 fmc). In the other California rivers, radiocarbon concentrations in DIC were generally below modern and lower than corresponding levels in DOC; in the case of the Santa Ana River, DOC was older than DIC as a result of wastewater inputs from upstream treatment plants. Together these data suggest that the carbonate equilibrium of California rivers is influenced by weathering of carbonate minerals which produces HCO3- with no 14C. We hypothesize that this dead carbon can move into aquatic foodwebs via algae and phytoplankton uptake during photosynthesis, depressing the 14C content of aquatic foodwebs below that of the atmosphere. Based on a simple two-component mixing model incorporating carbonate weathering and atmospheric CO2, we estimate that 15-17% of the carbon in the aquatic foodweb of Copper Basin is derived directly from mineral weathering of

High-precision chronology for Central American maize diversification from El Gigante rockshelter, Honduras.

PubMed

Kennett, Douglas J; Thakar, Heather B; VanDerwarker, Amber M; Webster, David L; Culleton, Brendan J; Harper, Thomas K; Kistler, Logan; Scheffler, Timothy E; Hirth, Kenneth

2017-08-22

The first steps toward maize ( Zea mays subspecies mays ) domestication occurred in the Balsas region of Mexico by ∼9,000 calendar years B.P. (cal B.P.), but it remains unclear when maize was productive enough to be a staple grain in the Americas. Molecular and microbotanical data provide a partial picture of the timing and nature of morphological change, with genetic data indicating that alleles for some domestication traits were not yet fixed by 5,300 cal B.P. in the highlands of Mexico. Here, we report 88 radiocarbon dates on the botanical remains from El Gigante rockshelter (Honduras) to establish a Bayesian chronology over the past ∼11,000 y spanning the transition to maize-based food production. Botanical remains are remarkably well preserved and include over 10,000 maize macrofossils. We directly dated 37 maize cobs to establish the appearance and local change of maize at the site. Cobs are common in deposits dating between 4,340 and 4,020 cal B.P., and again between 2,350 and 980 cal B.P. The earliest cobs appear robustly domesticated, having 10-14 rows, suggesting strong selection for increased yield. The later cobs are comparable to these earliest ones, but show clear emergence of diverse traits, including increased cob width, rachis segment length, and cupule width. Our results indicate that domesticated landraces of maize productive enough to be a staple grain existed in Central America by 4,300 cal B.P.

High-precision chronology for Central American maize diversification from El Gigante rockshelter, Honduras

PubMed Central

Kennett, Douglas J.; Thakar, Heather B.; VanDerwarker, Amber M.; Webster, David L.; Culleton, Brendan J.; Harper, Thomas K.; Kistler, Logan; Scheffler, Timothy E.; Hirth, Kenneth

2017-01-01

The first steps toward maize (Zea mays subspecies mays) domestication occurred in the Balsas region of Mexico by ∼9,000 calendar years B.P. (cal B.P.), but it remains unclear when maize was productive enough to be a staple grain in the Americas. Molecular and microbotanical data provide a partial picture of the timing and nature of morphological change, with genetic data indicating that alleles for some domestication traits were not yet fixed by 5,300 cal B.P. in the highlands of Mexico. Here, we report 88 radiocarbon dates on the botanical remains from El Gigante rockshelter (Honduras) to establish a Bayesian chronology over the past ∼11,000 y spanning the transition to maize-based food production. Botanical remains are remarkably well preserved and include over 10,000 maize macrofossils. We directly dated 37 maize cobs to establish the appearance and local change of maize at the site. Cobs are common in deposits dating between 4,340 and 4,020 cal B.P., and again between 2,350 and 980 cal B.P. The earliest cobs appear robustly domesticated, having 10–14 rows, suggesting strong selection for increased yield. The later cobs are comparable to these earliest ones, but show clear emergence of diverse traits, including increased cob width, rachis segment length, and cupule width. Our results indicate that domesticated landraces of maize productive enough to be a staple grain existed in Central America by 4,300 cal B.P. PMID:28784803

Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

PubMed

Harvey, Virginia L; Egerton, Victoria M; Chamberlain, Andrew T; Manning, Phillip L; Buckley, Michael

2016-01-01

Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N) and ratio of carbon to nitrogen (C:N). Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification) as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands), chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14)C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae), recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP). All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14)C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4)C analysis.

Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone

PubMed Central

Harvey, Virginia L.; Egerton, Victoria M.; Chamberlain, Andrew T.; Manning, Phillip L.; Buckley, Michael

2016-01-01

Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N) and ratio of carbon to nitrogen (C:N). Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification) as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands), chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six 14C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae), recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP). All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated 14C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 14C analysis. PMID:26938469

Results of Radiocarbon Dating of Holocene Deposits from the Sea of Azov

NASA Astrophysics Data System (ADS)

Matishov, G. G.; Kovaleva, G. V.; Arslanov, Kh. A.; Dyuzhova, K. V.; Polshin, V. V.; Zolotareva, A. E.

2018-04-01

New data on the absolute age of Quaternary bottom deposits from the Sea of Azov based on the results of radiocarbon analysis (14C) are presented. Overall, 67 radiocarbon dating of bottom deposits of New and Ancient Azov Ages were obtained. The thickness of sediments of the New Azov Age and their distribution over different areas of the Sea of Azov was determined during the study; the results obtained were compared with the reference data available. An integrated approach to the study of deposits, based on the combination of the biostratigraphy methods and the results of absolute age dating, was applied.

Atomic bomb: Ultimate faith of diplomacy. Research report, August 1992-April 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, S.

1993-04-01

This paper examines the development and use of the atomic bombs as the means of achieving a grand strategy formulated by United States President Franklin Roosevelt and British Prime Minister Winston Churchill as early as 1943. This grand strategy consisted of two main goals. First, if necessary, the atomic bombs would be used to end World War II as soon as they were ready. Second, the existence of the atomic bombs would be used as a diplomatic hammer to shape the political landscape of the postwar world - a direct warning to Soviet dictator Joseph Stalin not to attempt tomore » hegemonize Eastern Europe and the Far East. Was the grand strategy successfully accomplished. Could newly sworn President Harry Truman have employed diplomatic means to quickly and successfully end World War II without resorting to the use of the atomic bombs against Japan.« less

Jewish Holocaust Histories and the Work of Chronological Narratives

ERIC Educational Resources Information Center

Silverstein, Jordana

2012-01-01

This article examines the ways that, in Holocaust education in Jewish schools in Melbourne and New York at the beginning of the 21st century, knowledge of the Holocaust is transferred to students in chronological form. It begins by asking: What work do chronological narratives do within the Holocaust historical narratives offered within Jewish…

Sensitivity of simulated deep ocean natural radiocarbon to gas exchange velocity and historical atmospheric Δ14C variations

NASA Astrophysics Data System (ADS)

Wagner, Hannes; Koeve, Wolfgang; Kriest, Iris; Oschlies, Andreas

2015-04-01

Simulated deep ocean natural radiocarbon is frequently used to assess model performance of deep ocean ventilation in Ocean General Circulation Models (OGCMs). It has been shown to be sensitive to a variety of model parameters, such as the mixing parameterization, convection scheme and vertical resolution. Here we use three different ocean models (MIT2.8, ECCO, UVic) to evaluate the sensitivity of simulated deep ocean natural radiocarbon to two other factors, while keeping the model physics constant: (1) the gas exchange velocity and (2) historic variations in atmospheric Δ^1^4C boundary conditions. We find that simulated natural Δ^1^4C decreases by 14-20 ‰ throughout the deep ocean and consistently in all three models, if the gas exchange velocity is lowered by 30 % with respect to the OCMIP-2 protocol, to become more consistent with newer estimates of the oceans uptake of bomb derived ^1^4C. Simulated deep ocean natural Δ^1^4C furthermore decreases by 3-9 ‰ throughout the deep Pacific, Indian and Southern Oceans and consistently in all three models, if the models are forced with the observed atmospheric Δ^1^4C history, instead of an often made pragmatic assumption of a constant atmospheric Δ^1^4C value of zero. Applying both improvements (gas exchange reduction, as well as atmospheric Δ^1^4C history implementation) concomitantly and accounting for the present uncertainty in gas exchange velocity estimates (between 10 and 40 % reduction with respect to the OCMIP-2 protocol) simulated deep ocean Δ^1^4C decreases by 10-30 ‰ throughout the deep Pacific, Indian and Southern Ocean. This translates to a ^1^4C-age increase of 100-300 years and indicates, that models, which in former assessments (based on the OCMIP-2 protocol) had been identified to have an accurate deep ocean ventilation, should now be regarded as rather having a bit too sluggish a ventilation. Models, which on the other hand had been identified to have a bit too fast a deep ocean ventilation

Holocene erosion, sedimentation, and stratigraphy at Raven Fork, Southern Blue Ridge Mountains, USA

Treesearch

David S. Leigh; Paul A. Webb

2006-01-01

Holocene colluvial and alluvial stratigraphy and a radiocarbon chronology are presented for the valley of the lower three kilometers of Raven Fork, a mountain stream draining 194 km2 of high relief (1.3 km) terrain of the Southern Blue Ridge Mountains in western North Carolina, USA, which is in a region that lacks good chronological data. Lower hillslopes, alluvial/...

From classified to commonplace: the trajectory of the hydrogen bomb 'secret'.

PubMed

Wellerstein, Alex

2008-06-01

The secret of the hydrogen bomb went from being an icon of nuclear secrecy to something that could be widely reproduced on the Internet and in children's textbooks. The rise and fall of the H-bomb secret reveals both changing attitudes towards state secrecy in general and the contingent nature of secrecy, depending on an imagined threat as guidance.

AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar.

PubMed

Patrut, Adrian; Patrut, Roxana T; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A; von Reden, Karl F

2016-01-01

The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old.

Trauma, grief and depression in Nairobi children after the 1998 bombing of the American Embassy.

PubMed

Pfefferbaum, Betty; North, Carol S; Doughty, Debby E; Pfefferbaum, Rose L; Dumont, Cedric E; Pynoos, Robert S; Gurwitch, Robin H; Ndetei, David

2006-01-01

Despite the increasingly dangerous world where trauma and loss are common, relatively few studies have explored traumatic grief in children. The 1998 American Embassy bombing in Nairobi, Kenya, provided an unfortunate opportunity to examine this topic. This report describes findings in 156 children who knew someone killed in the incident, assessed 8 to 14 months after the explosion. Bomb-related posttraumatic stress was associated with physical exposure, acute response, posttraumatic stress related to other negative life events, type of bomb-related loss, and subsequent loss. Grief was associated with bomb-related posttraumatic stress, posttraumatic stress related to other negative life events, and type of bomb-related loss. The study supports the developing literature on traumatic grief and the need for studies exploring the potentially unique aspects of this construct.

Nuclear shadows on silvered walls: Atomic Bomb Cinema, from 1935 to 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shapiro, J.F.

1991-01-01

The cinema and the atomic bomb are two of the most significant technological innovations of the past-century - their influence on culture has provoked tremendous political, academic, and popular debate. The point at which these two technologies intersect is what the author calls Atomic Bomb Cinema.' Since 1945 almost six hundred films with images of nuclear weapons have been released in the US, and they have been virtually ignored by everyone but the film going public. This study shows how Bomb films' use recurring themes and formal structures, and therefore must be treated as a coherent body of films; identifiesmore » historical, mythological, and contemporary motifs; and analyzes these films from two points of view: interdisciplinary (history, politics, economics, sociology, and aesthetics) and cross-cultural (American, Japanese, British, and Australian). The most important element of Atomic Bomb Cinema is the Apocalyptic Imagination; film makers use it to structure their narratives and explore a wide range of ideological issues. In contrast to commonly held beliefs, Atomic Bomb Cinema is undeniably part of a process that helps people to understand the threat of nuclear war. In this instance, the cinema is one cultural institution that contributes to a healthy society.« less

Future use of tritium in mapping pre-bomb groundwater volumes.

PubMed

Eastoe, C J; Watts, C J; Ploughe, M; Wright, W E

2012-01-01

The tritium input to groundwater, represented as volume-weighted mean tritium concentrations in precipitation, has been close to constant in Tucson and Albuquerque since 1992, and the decrease in tritium concentrations at the tail end of the bomb tritium pulse has ceased. To determine the future usefulness of tritium measurements in southwestern North America, volume-weighted mean tritium levels in seasonal aggregate precipitation samples have been gathered from 26 sites. The averages range from 2 to 9 tritium units (TU). Tritium concentrations increase with site latitude, and possibly with distance from the coast and with site altitude, reflecting local ratios of combination of low-tritium moisture advected from the oceans with high-tritium moisture originating near the tropopause. Tritium used alone as a tool for mapping aquifer volumes containing only pre-bomb recharge to groundwater will become ambiguous when the tritium in precipitation at the end of the bomb tritium pulse decays to levels close to the analytical detection limit. At such a time, tritium in precipitation from the last one to two decades of the bomb pulse will become indistinguishable from pre-bomb recharge. The threshold of ambiguity has already arrived in coastal areas with a mean of 2 TU in precipitation and will follow in the next three decades throughout the study region. Where the mean tritium level is near 5 TU, the threshold will occur between 2025 and 2030, given a detection limit of 0.6 TU. Similar thresholds of ambiguity, with different local timing possible, apply globally. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

Dr. Lytle Adams' incendiary "bat bomb" of World War II.

PubMed

Christen, Arden G; Christen, Joan A

2004-11-01

On December 7, 1941, a 60-year old dentist from Irwin, Pennsylvania, Dr. Lytle S. Adams, was driving home from a vacation at Carlsbad Caverns in New Mexico. Hours earlier, he had been gripped with amazement as he witnessed millions of bats exiting the caves of Carlsbad. Listening to his car radio on his return trip, he was shocked to hear that Japan had just attacked Pearl Harbor. Dr. Adams, outraged over this travesty, began to mentally construct a plan for U.S. retaliation. As his thoughts returned to the countless bats that had awed him, he formed a tentative plan: millions of these small, flying mammals could be connected to tiny, time-fused incendiary bombs, and then released to land on the flimsily constructed structures which dotted the cities of Japan. Within a few minutes, the bombs would explode and enflame the entire urban areas. He postulated that these immeasurable numbers of fires, spreading their devastation over such vast areas within Japanese cities would result in the enemy's speedy surrender. This article documents the futile efforts of Dr. Adams, his team and the U.S. government to develop and employ an effective, incendiary bat bomb. The recently developed atom bomb, a far more deadly weapon was used in its place.

Characteristic expression of fukutin in gastric cancer among atomic bomb survivors.

PubMed

Pham, Trang T B; Oue, Naohide; Yamamoto, Manabu; Fujihara, Megumu; Ishida, Teruyoshi; Mukai, Shoichiro; Sakamoto, Naoya; Sentani, Kazuhiro; Yasui, Wataru

2017-02-01

Approximately 70 years have passed since the atomic bombs were dropped on Nagasaki and Hiroshima. To elucidate potential biomarkers and possible mechanisms of radiation-induced cancer, the expression of FKTN , which encodes fukutin protein and causes Fukuyama-type congenital muscular dystrophy, was analyzed in gastric cancer (GC) tissue samples from atomic bomb survivors. Expression of cluster of differentiation (CD) 10 was also evaluated, as it has previously been observed that positive fukutin expression was frequently noted in CD10-positive GC cases. In the first cohort from Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital (Hiroshima, Japan; n=92), 102 (53%) of the GC cases were positive for fukutin. Expression of fukutin was not associated with exposure status, but was associated with CD10 expression (P=0.0001). The second cohort was from Hiroshima University Hospital (Hiroshima, Japan; n=86), and these patients were also in the Life Span Study cohort, in which atomic bomb radiation doses were precisely estimated using the DS02 system. Expression of fukutin was detected in 58 (67%) of GC cases. GC cases positive for fukutin were observed more frequently in the low dose-exposed group than in the high dose-exposed group (P=0.0001). Further studies with a larger cohort, including precise radiation dose estimation, may aid in clarifying whether fukutin could serve as a potential biomarker to define radiation-induced GC in atomic-bomb survivors.

Characteristic expression of fukutin in gastric cancer among atomic bomb survivors

PubMed Central

Pham, Trang T.B.; Oue, Naohide; Yamamoto, Manabu; Fujihara, Megumu; Ishida, Teruyoshi; Mukai, Shoichiro; Sakamoto, Naoya; Sentani, Kazuhiro; Yasui, Wataru

2017-01-01

Approximately 70 years have passed since the atomic bombs were dropped on Nagasaki and Hiroshima. To elucidate potential biomarkers and possible mechanisms of radiation-induced cancer, the expression of FKTN, which encodes fukutin protein and causes Fukuyama-type congenital muscular dystrophy, was analyzed in gastric cancer (GC) tissue samples from atomic bomb survivors. Expression of cluster of differentiation (CD) 10 was also evaluated, as it has previously been observed that positive fukutin expression was frequently noted in CD10-positive GC cases. In the first cohort from Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital (Hiroshima, Japan; n=92), 102 (53%) of the GC cases were positive for fukutin. Expression of fukutin was not associated with exposure status, but was associated with CD10 expression (P=0.0001). The second cohort was from Hiroshima University Hospital (Hiroshima, Japan; n=86), and these patients were also in the Life Span Study cohort, in which atomic bomb radiation doses were precisely estimated using the DS02 system. Expression of fukutin was detected in 58 (67%) of GC cases. GC cases positive for fukutin were observed more frequently in the low dose-exposed group than in the high dose-exposed group (P=0.0001). Further studies with a larger cohort, including precise radiation dose estimation, may aid in clarifying whether fukutin could serve as a potential biomarker to define radiation-induced GC in atomic-bomb survivors. PMID:28356981

Radiocarbon content in the annual tree rings during last 150 years and time variation of cosmic rays

NASA Technical Reports Server (NTRS)

Kocharov, G. E.; Metskvarishvili, R. Y.; Tsereteli, S. L.

1985-01-01

The results of the high accuracy measurements of radiocarbon abundance in precisely dated tree rings in the interval 1800 to 1950 yrs are discussed. Radiocarbon content caused by solar activity is established. The temporal dependence of cosmic rays is constructed, by use of radio abundance data.

New radiocarbon dates on the cereals from Wadi Kubbaniya

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wendorf, F.; Schild, R.; Close, A.E.

1984-01-01

In 1978, three carbonized grains of barley and a carbonized grain of einkorn wheat were found in a buried hearth at a Late Paleolithic site at Wadi Kubbaniya in Egypt. In 1981, two large clusters of barley seeds, which were identified as six-row barley and thus domestic, were found at a nearby site of comparable age. Numerous grinding stones, presumed to have been used for processing the cereals, were found in these and other sites, often deeply buried, and 30 radiocarbon dates placed the occupations between 18,500 and 17,000 radiocarbon years ago. These finds led us to suggest an earlymore » origin of food production, with implications for the initial development of complex societies. Several barley seeds were analyzed by electron spin resonance spectroscopy to determine the maximal temperature to which they had been subjected before burial. Six barley seeds and three small pieces of wood charcoal were dated directly by using a tandem accelerator mass spectrometer.« less

International Terrorism: A Chronology, 1968-1974

DTIC Science & Technology

1975-03-01

Tabacos , Argentina’s largest ciga- rette company and a subsidiary of British-Ameri- can Tobacco Co., was kidnapped outside of his home in Buenos Aires...presumably as part of the IRA’s worldwide letter-bomb cam- paign. 445. September 23 Argentina. David George Heywood of Nobleza Tabacos , a subsidiary of

Cartridge output testing - Methods to overcome closed-bomb shortcomings

NASA Technical Reports Server (NTRS)

Bement, Laurence J.; Schimmel, Morry L.

1991-01-01

Although the closed-bomb test has achieved virtually universal acceptance for measuring the output performance of pyrotechnic cartridges, there are serious shortcomings in its ability to quantify the performance of cartridges used as energy sources for pyrotechnic-activated mechanical devices. This paper presents several examples of cartridges (including the NASA Standard Initiator NSI) that successfully met closed-bomb performance requirements, but resulted in functional failures in mechanisms. To resolve these failures, test methods were developed to demonstrate a functional margin, based on comparing energy required to accomplish the function to energy deliverable by the cartridge.

Cancer and non-cancer effects in Japanese atomic bomb survivors.

PubMed

Little, M P

2009-06-01

The survivors of the atomic bombings in Hiroshima and Nagasaki are a general population of all ages and sexes and, because of the wide and well characterised range of doses received, have been used by many scientific committees (International Commission on Radiological Protection (ICRP), United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), Biological Effects of Ionizing Radiations (BEIR)) as the basis of population cancer risk estimates following radiation exposure. Leukaemia was the first cancer to be associated with atomic bomb radiation exposure, with preliminary indications of an excess among the survivors within the first five years after the bombings. An excess of solid cancers became apparent approximately ten years after radiation exposure. With increasing follow-up, excess risks of most cancer types have been observed, the major exceptions being chronic lymphocytic leukaemia, and pancreatic, prostate and uterine cancer. For most solid cancer sites a linear dose response is observed, although in the latest follow-up of the mortality data there is evidence (p = 0.10) for an upward curvature in the dose response for all solid cancers. The only cancer sites which exhibit (upward) curvature in the dose response are leukaemia, and non-melanoma skin and bone cancer. For leukaemia the dose response is very markedly upward curving, indeed largely describable as a pure quadratic dose response, particularly in the low dose (0-2 Sv) range. Even 55 years after the bombings over 40% of the Life Span Study cohort remain alive, so continued follow-up of this group is vital for completing our understanding of long-term radiation effects in people. In general, the relative risks per unit dose among the Japanese atomic bomb survivors are greater than those among comparable subsets in studies of medically exposed individuals. Cell sterilisation largely accounts for the discrepancy in relative risks between these two populations, although other

Education, Income, and Support for Suicide Bombings: Evidence from Six Muslim Countries

ERIC Educational Resources Information Center

Shafiq, M. Najeeb; Sinno, Abdulkader H.

2010-01-01

The authors examine the effect of educational attainment and income on support for suicide bombing among Muslim publics in six predominantly Muslim countries that have experienced suicide bombings: Indonesia, Jordan, Lebanon, Morocco, Pakistan, and Turkey. The authors make two contributions. First, they present a conceptual model, which has been…

Radiocarbon dating of extinct fauna in the Americas recovered from tar pits

NASA Astrophysics Data System (ADS)

Jull, A. J. T.; Iturralde-Vinent, M.; O'Malley, J. M.; MacPhee, R. D. E.; McDonald, H. G.; Martin, P. S.; Moody, J.; Rincón, A.

2004-08-01

We have obtained radiocarbon dates by accelerator mass spectrometry on bones of extinct large mammals from tar pits. Results on some samples of Glyptodon and Holmesina (extinct large mammals similar to armadillos) yielded ages of >25 and >21 ka, respectively. We also studied the radiocarbon ages of three different samples of bones from the extinct Cuban ground sloth, Parocnus bownii, which yielded dates ranging from 4960 ± 280 to 11 880 ± 420 yr BP. In order to remove the tar component pretreat the samples sufficiently to obtain reliable dates, we cleaned the samples by Soxhlet extraction in benzene. Resulting samples of collagenous material were often small.

The Rhetoric of "Unconditional Surrender" and the Decision to Drop the Atomic Bomb.

ERIC Educational Resources Information Center

Hikins, James W.

1983-01-01

Analyzes the decision to drop the atomic bomb from a rhetorical point of view, arguing that the bombs were launched because of an American commitment to a particular rhetoric that focused on the propaganda slogan "unconditional surrender." (PD)

Psychiatric disorders after terrorist bombings among rescue workers and bombing survivors in Nairobi and rescue workers in Oklahoma City.

PubMed

Zhang, Gus; Pfefferbaum, Betty; Narayanan, Pushpa; Lee, Sungkyu; Thielman, Samuel; North, Carol S

2016-02-01

To examine the prevalence of psychopathology in 52 male rescue workers responding to the 1998 U.S. Embassy bombing in Nairobi, Kenya, comparing them with 176 male rescue workers responding to the 1995 Oklahoma City, Oklahoma, bombing and with 105 directly exposed male civilian survivors of the Nairobi bombing. The Diagnostic Interview Schedule/Disaster Supplement assessed pre-disaster and post-disaster psychiatric disorders and variables related to demographics, exposure, disaster perceptions, and coping in all 3 disaster subgroups. The most prevalent post-disaster disorders were posttraumatic stress disorder (PTSD) (22%) and major depressive disorder (MDD) (27%) among Nairobi rescue workers, which were more than 2 and 4 times higher, respectively, than among Oklahoma City rescue workers. Alcohol use disorder was the most prevalent pre- and post-disaster disorder among Oklahoma City rescue workers. Nairobi rescue workers had a prevalence of PTSD and MDD not significantly different from Nairobi civilian survivors. Nairobi rescue workers were more symptomatic than Oklahoma City rescue workers and were as symptomatic as Nairobi civilian survivors. The vulnerability of Nairobi rescue workers to psychological sequelae may be a reflection of their volunteer, rather than professional, status. These findings contribute to understanding rescue worker mental health, especially among volunteer rescue workers, with potential implications for the importance of professional status of rescue workers in conferring protection from adverse mental health outcomes.

The scientific value and potential of New Zealand swamp kauri

NASA Astrophysics Data System (ADS)

Lorrey, Andrew M.; Boswijk, Gretel; Hogg, Alan; Palmer, Jonathan G.; Turney, Christian S. M.; Fowler, Anthony M.; Ogden, John; Woolley, John-Mark

2018-03-01

New Zealand swamp kauri (Agathis australis) are relic trees that have been buried and preserved in anoxic bog environments of northern New Zealand for centuries through to hundreds of millennia. Kauri are massive in proportion to other native New Zealand trees and they can attain ages greater than 1000 years. The export market for swamp (subfossil) kauri has recently been driven by demand for a high-value workable timber, but there are concerns about the sustainability of the remaining resource, a situation exacerbated in recent years by the rapid extraction of wood. Economic exploitation of swamp kauri presents several unique opportunities for Quaternary science, however the scientific value of this wood is not well understood by the wider research community and public. Here, we summarise the history of scientific research on swamp kauri, and explore the considerable potential of this unique resource. Swamp kauri tree-ring chronologies are temporally unique, and secondary analyses (such as radiocarbon and isotopic analyses) have value for improving our understanding of Earth's recent geologic history and pre-instrumental climate history. Swamp kauri deposits that span the last interglacial-glacial cycle show potential to yield "ultra-long" multi-millennia tree-ring chronologies, and composite records spanning large parts of MIS3 (and most of the Holocene) may be possible. High-precision radiocarbon dating of swamp kauri chronologies can improve the resolution of the global radiocarbon calibration curve, while testing age modelling and chronologic alignment of other independent long-term high-resolution proxy records. Swamp kauri also has the potential to facilitate absolute dating and verification of cosmogenic events found in long Northern Hemisphere tree-ring chronologies. Future efforts to conserve these identified values requires scientists to work closely with swamp kauri industry operators, resource consent authorities, and export regulators to mitigate

Education, Income and Support for Suicide Bombings: Evidence from Six Muslim Countries

ERIC Educational Resources Information Center

Shafiq, M. Najeeb; Sinno, Abdulkader H.

2009-01-01

We examine the effect of educational attainment and income on support for suicide bombing among Muslim publics in six predominantly Muslim countries that have experienced suicide bombings: Indonesia, Jordan, Lebanon, Morocco, Pakistan, and Turkey. We make two contributions. First, we present a conceptual model, which has been lacking in the…

Fast neutrons measured in copper from the Hiroshima atomic bomb dome.

PubMed

Marchetti, A A; McAninch, J E; Rugel, G; Rühm, W; Korschinek, G; Martinelli, R E; Faestermann, T; Knie, K; Egbert, S D; Wallner, A; Wallner, C; Tanaka, K; Endo, S; Hoshi, M; Shizuma, K; Fujita, S; Hasai, H; Imanaka, T; Straume, T

2009-01-01

The first measurements of (63)Ni produced by A-bomb fast neutrons (above approximately 1 MeV) in copper samples from Hiroshima encompassed distances from approximately 380 to 5062 m from the hypocenter (the point on the ground directly under the bomb). They included the region of interest to survivor studies (approximately 900 to 1500 m) and provided the first direct validation of fast neutrons in that range. However, a significant measurement gap remained between the hypocenter and 380 m. Measurements close to the hypocenter are important as a high-value anchor for the slope of the curve for neutron activation as a function of distance. Here we report measurements of (63)Ni in copper samples from the historic Hiroshima Atomic Bomb Dome, which is located approximately 150 m from the hypocenter. These measurements extend the range of our previously published data for (63)Ni providing a more comprehensive and consistent A-bomb activation curve. The results are also in good agreement with calculations based on the current dosimetry system (DS02) and give further experimental support to the accuracy of this system that forms the basis for radiation risk estimates worldwide.

"US-detonated nano bombs" facilitate targeting treatment of resistant breast cancer.

PubMed

Shi, Jinjin; Liu, Wei; Fu, Yu; Yin, Na; Zhang, Hongling; Chang, Junbiao; Zhang, Zhenzhong

2018-03-28

Reversal of drug resistance and targeted therapy are the keys but remain challenging in resistant breast cancer treatment. Herein, low frequency ultrasound detonated "nano bombs" were rationally designed and used for treatment of resistant breast cancer. For the 'nano bombs', the ammunition (Doxorubicin, DOX) was loaded into the ammunition depot (hollow mesoporous TiO 2 , MTNs), and the safety device (dsDNA) was wrapped on the surface of MTNs to avoid the unexpected DOX release. We found the "US-detonated explosive" abilities of "nano bomb" MTNs (NBMTNs), including explosive generation of ROS, explosive release of DOX, US-triggered lysosome escape and mitochondrial targeting in the in vitro and in vivo studies. More importantly, the drug resistance of MCF-7/ADR cells could be reversed via the inhibition of mitochondrial energy supply approach caused by the "explosion" of NBMTNs. Furthermore, NBMTNs combined the superior chemotherapy efficacy of DOX and potent SDT efficacy in one single platform and significantly enhanced the anticancer efficacy. Our results demonstrate an approach for reversing resistance and specific targeting of tumors using 'US-detonated nano bombs'. Copyright © 2018 Elsevier B.V. All rights reserved.

Bomb blast mass casualty incidents: initial triage and management of injuries.

PubMed

Goh, S H

2009-01-01

Bomb blast injuries are no longer confined to battlefields. With the ever present threat of terrorism, we should always be prepared for bomb blasts. Bomb blast injuries tend to affect air-containing organs more, as the blast wave tends to exert a shearing force on air-tissue interfaces. Commonly-injured organs include the tympanic membranes, the sinuses, the lungs and the bowel. Of these, blast lung injury is the most challenging to treat. The clinical picture is a mix of acute respiratory distress syndrome and air embolism, and the institution of positive pressure ventilation in the presence of low venous pressures could cause systemic arterial air embolism. The presence of a tympanic membrane perforation is not a reliable indicator of the presence of a blast injury in the other air-containing organs elsewhere. Radiological imaging of the head, chest and abdomen help with the early identification of blast lung injury, head injury, abdominal injury, eye and sinus injuries, as well as any penetration by foreign bodies. In addition, it must be borne in mind that bomb blasts could also be used to disperse radiological and chemical agents.

Mass casualties in the Oklahoma City bombing.

PubMed

Teague, David C

2004-05-01

The Alfred P. Murrah Federal Building in Oklahoma City was partially destroyed by a terrorist bomb on April 19, 1995. Injuries were sustained by 759 people, 168 of whom died. Fatalities occurred primarily among victims in the collapse zone of the federal building. Only 83 survivors required hospitalization. Twenty-two surviving victims sustained multiple fractures. Most victims arrived at local emergency departments by private vehicle within 2 hours. More severely injured survivors were transported by ambulance. The closer receiving hospitals used emergency department facilities and minor treatment areas. Few survivors were extricated from the bombing site more than 3 hours after the detonation. Mass casualty plans must provide for improved communications, diversion and retriage from facilities nearest the disaster site, and effective coordination of community and hospital resources.

Alterations of body mass index and body composition in atomic bomb survivors.

PubMed

Tatsukawa, Y; Misumi, M; Yamada, M; Masunari, N; Oyama, H; Nakanishi, S; Fukunaga, M; Fujiwara, S

2013-08-01

Obesity, underweight, sarcopenia and excess accumulation of abdominal fat are associated with a risk of death and adverse health outcomes. Our aim was to determine whether body mass index (BMI) and body composition, assessed with dual-energy X-ray absorptiometry (DXA), are associated with radiation exposure among atomic bomb (A-bomb) survivors. This was a cross-sectional study conducted in the Adult Health Study of the Radiation Effects Research Foundation. We examined 2686 subjects (834 men and 1852 women), aged 48-89 years (0-40 years at A-bomb exposure), for BMI analysis. Among them, 550 men and 1179 women underwent DXA in 1994-1996 and were eligible for a body composition study. After being adjusted for age and other potential confounding factors, A-bomb radiation dose was associated significantly and negatively with BMI in both sexes (P=0.01 in men, P=0.03 in women) and appendicular lean mass (P<0.001 in men, P=0.05 in women). It was positively associated with trunk-to-limb fat ratio in women who were less than 15 years old at the time of exposure (P=0.03). This is the first study to report a significant dose response for BMI and body composition 50 years after A-bomb radiation exposure. We will need to conduct further studies to evaluate whether these alterations affect health status.

New radiocarbon dating and demographic insights into San Juan ante Portam Latinam, a possible Late Neolithic war grave in North-Central Iberia.

PubMed

Fernández-Crespo, Teresa; Schulting, Rick J; Ordoño, Javier; Duering, Andreas; Etxeberria, Francisco; Herrasti, Lourdes; Armendariz, Ángel; Vegas, José I; Bronk Ramsey, Christopher

2018-03-15

San Juan ante Portam Latinam is one of a small number of European Neolithic sites meeting many of the archaeological criteria expected for a mass grave, and furthermore presents evidence for violent conflict. This study aims to differentiate between what is potentially a single episode of deposition, versus deposition over some centuries, or, alternatively, that resulting from a combination of catastrophic and attritional mortality. The criteria developed are intended to have wider applicability to other such proposed events. Ten new AMS 14 C determinations on human bone from the site, together with previously available dates, are analyzed through Bayesian modeling to refine the site's chronology. This is used together with the population's demographic profile as the basis for agent-based demographic modeling. The new radiocarbon results, while improving the site's chronology, fail to resolve the question whether the burial represents a single event, or deposition over decades or centuries-primarily because the dates fall within the late fourth millennium BC plateau in the calibration curve. The demographic modeling indicates that the population's age and sex distribution fits neither a single catastrophic event nor a fully attritional mortality profile, but instead may partake of elements of both. It is proposed that San Juan ante Portam Latinam was used as burial place for the mainly adolescent and adult male dead of a particular or multiple violent engagements (e.g., battles), while previously or subsequently seeing use for attritional burial by other members of one or more surrounding communities dead over the course of a few generations. The overall bias towards males, particularly to the extent that many may represent conflict mortality, has implications for the structure of the surviving community, the members of which may have experienced increased vulnerability in the face of neighboring aggressors. © 2018 Wiley Periodicals, Inc.

Myth-building: The [open quotes]Islamic[close quotes] bomb

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoodbhoy, P.

1993-06-01

The [open quotes]Islamic Bomb[close quotes] is roughly understood to be a nuclear weapon aquired for broad ideological reasons--a weapon that supposedly belongs to the Muslim [ital ummah] or community and, as such, is the ultimate expression of Islamic solidarity. Concern about the Islamic bomb is at the heart of the intense effort to prevent the spread of nuclear weapons to Muslim countries. The official justification is a general one: proliferation must be curbed globally. But unofficially, the Islamic bomb gets special attention. The reasons behind this special attention are described in this article. The reasons include fear of terrorism, ofmore » a [ital jihad] willing to indiscriminately use nuclear weapons in hope of a reward in the Hereafter, and of the transfer of nuclear arms from nuclear to non-nuclear Muslim countries in times of crisis. Possibilities for controlling the proliferation of nuclear weapons in Muslim countries are addressed. Reasons are cited as to why various Muslim countries wish to acquire nuclear weapons.« less

Cartel Car Bombings in Mexico

DTIC Science & Technology

2013-08-01

English and Spanish language media reports, Borderland Beat, available from www.borderlandbeat.com, Blog Del Naco, avail- able from...Departamento Administradora de Seguridad en Proceso de Supresión) DEA Drug Enforcement Administration DHS Department of Homeland...the official said in Spanish . ‘Car bombs have been employed in Nuevo Laredo, Monterrey, Victoria and the Tamaulipas coast city of Tampico, which

Delivering More Than Bombs: The Utility of Long-Range Strike Platforms

DTIC Science & Technology

2012-06-01

strategic in the consequences of their actions” in Colin S. Gray, Explorations in Strategy (New York: Praeger, 1998), 61. Strategic bombing does not...LRS-B 3 Air Force Priorities for a New Strategy with Constrained Budgets, Office of the Chief of Staff of the...17 to battle, the defensive nature of US air strategy all but disappeared. The proponents of long-range strategic bombing quickly gained support

A graphical method to evaluate predominant geochemical processes occurring in groundwater systems for radiocarbon dating

USGS Publications Warehouse

Han, Liang-Feng; Plummer, Niel; Aggarwal, Pradeep

2012-01-01

A graphical method is described for identifying geochemical reactions needed in the interpretation of radiocarbon age in groundwater systems. Graphs are constructed by plotting the measured 14C, δ13C, and concentration of dissolved inorganic carbon and are interpreted according to specific criteria to recognize water samples that are consistent with a wide range of processes, including geochemical reactions, carbon isotopic exchange, 14C decay, and mixing of waters. The graphs are used to provide a qualitative estimate of radiocarbon age, to deduce the hydrochemical complexity of a groundwater system, and to compare samples from different groundwater systems. Graphs of chemical and isotopic data from a series of previously-published groundwater studies are used to demonstrate the utility of the approach. Ultimately, the information derived from the graphs is used to improve geochemical models for adjustment of radiocarbon ages in groundwater systems.

Rapid intercontinental air pollution transport associated with a meteorological bomb

NASA Astrophysics Data System (ADS)

Stohl, A.; Huntrieser, H.; Richter, A.; Beirle, S.; Cooper, O.; Eckhardt, S.; Forster, C.; James, P.; Spichtinger, N.; Wenig, M.; Wagner, T.; Burrows, J.; Platt, U.

2003-04-01

Intercontinental transport (ICT) of trace substances normally occurs on timescales ranging from a few days to several weeks. In this paper an extraordinary episode in November 2001 is presented, where pollution transport across the North Atlantic took only about one day. The transport mechanism, termed here an intercontinental pollution express highway, was exceptional, as it involved an explosively generated cyclone, a so-called meteorological "bomb". To the authors' knowledge, this is the first study describing pollution transport in a bomb. The discovery of this event was based on transport model calculations and satellite measurements of NO2, a species with a relatively short lifetime in the atmosphere, which could be transported that far only because of the high wind speeds produced by the bomb. A 15-year transport climatology shows that intercontinental express highways are about four times more frequent in winter than in summer, in agreement with bomb climatologies. The climatology furthermore reveals that intercontinental express highways may be important for the budget of short-lived substances in the remote troposphere. For instance, for a substance with a lifetime of 1 day, express highways may be responsible for about two thirds of the total ICT. A rough calculation suggests that express highways connecting North America with Europe enhance the average NOx mixing ratios over Europe, due to North American emissions, by about 2-3 pptv in winter.

AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar

PubMed Central

Patrut, Adrian; Patrut, Roxana T.; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A.; von Reden, Karl F.

2016-01-01

The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old. PMID:26760300

Biomarkers of Radiosensitivity in A-Bomb Survivors Pregnant at the Time of Bombings in Hiroshima and Nagasaki

DOE PAGES

Miles, Edward F.; Tatsukawa, Yoshimi; Funamoto, Sachiyo; ...

2011-01-01

Purpose . There is evidence in the literature of increased maternal radiosensitivity during pregnancy. Materials and Methods . We tested this hypothesis using information from the atomic-bomb survivor cohort, that is, the Adult Health Study database at the Radiation Effects Research Foundation, which contains data from a cohort of women who were pregnant at the time of the bombings of Hiroshima and Nagasaki. Previous evaluation has demonstrated long-term radiation dose-response effects. Results/Conclusions . Data on approximately 250 women were available to assess dose-response rates for serum cholesterol, white blood cell count, erythrocyte sedimentation rate, and serum hemoglobin, and on approximatelymore » 85 women for stable chromosome aberrations, glycophorin A locus mutations, and naïve CD4 T-cell counts. Although there is no statistically significant evidence of increased radiosensitivity in pregnant women, the increased slope of the linear trend line in the third trimester with respect to stable chromosome aberrations is suggestive of an increased radiosensitivity.« less

[Radiocarbon dating of pollen and spores in wedge ice from Iamal and Kolyma].

PubMed

Vasil'chuk, A K

2004-01-01

Radiocarbon dating of pollen concentrate from late Pleistocene syngenetic wedge ice was carried out using acceleration mass spectrometry (AMS) in Seyakha and Bizon sections. Comparison of the obtained dating with palynological analysis and AMS radiocarbon dating previously obtained for other organic fractions of the same samples allowed us to evaluate accuracy of dating of different fractions. Quantitative tests for data evaluation were considered in terms of possible autochthonous or allochthonous accumulation of the material on the basis of pre-Pleistocene pollen content in these samples. Paleoecological information content of pollen spectra from late Pleistocene syngenetic wedge ice was evaluated.

Thyroid Dysfunction and Autoimmune Thyroid Diseases Among Atomic Bomb Survivors Exposed in Childhood.

PubMed

Imaizumi, Misa; Ohishi, Waka; Nakashima, Eiji; Sera, Nobuko; Neriishi, Kazuo; Yamada, Michiko; Tatsukawa, Yoshimi; Takahashi, Ikuno; Fujiwara, Saeko; Sugino, Keizo; Ando, Takao; Usa, Toshiro; Kawakami, Atsushi; Akahoshi, Masazumi; Hida, Ayumi

2017-07-01

The risk of thyroid cancer increases and persists for decades among individuals exposed to ionizing radiation in childhood, although the long-term effects of childhood exposure to medium to low doses of radiation on thyroid dysfunction and autoimmune thyroid diseases have remained unclear. To evaluate radiation dose responses for the prevalence of thyroid dysfunction and autoimmune thyroid disease among atomic bomb survivors exposed in childhood. Hiroshima and Nagasaki atomic bomb survivors who were younger than 10 years old at exposure underwent thyroid examinations at the Radiation Effects Research Foundation between 2007 and 2011, which was 62 to 66 years after the bombing. Data from 2668 participants (mean age, 68.2 years; 1455 women) with known atomic bomb thyroid radiation doses (mean dose, 0.182 Gy; dose range, 0 to 4.040 Gy) were analyzed. Dose-response relationships between atomic bomb radiation dose and the prevalence of hypothyroidism, hyperthyroidism (Graves' disease), and positive for antithyroid antibodies. Prevalences were determined for hypothyroidism (129 cases, 7.8%), hyperthyroidism (32 cases of Graves' disease, 1.2%), and positive for antithyroid antibodies (573 cases, 21.5%). None of these was associated with thyroid radiation dose. Neither thyroid antibody-positive nor -negative hypothyroidism was associated with thyroid radiation dose. Additional analyses using alternative definitions of hypothyroidism and hyperthyroidism found that radiation dose responses were not significant. Radiation effects on thyroid dysfunction and autoimmune thyroid diseases were not observed among atomic bomb survivors exposed in childhood, at 62 to 66 years earlier. The cross-sectional design and survival bias were limitations of this study. Copyright © 2017 Endocrine Society

Blacks in America 1492-1970. A Chronology and Fact Book.

ERIC Educational Resources Information Center

Sloan, Irving J., Comp.

Many unacknowledged contributions made by black individuals to American civilization from 1492 to 1970 are enumerated in this compact book, one of a series of ethnic chronologies. Intended primarily as a reference work, a major part of this book is the factual chronological listing of achievements negroes made throughout United States history as…

The Manhattan Project: Making the Atomic Bomb. 1999 edition.

DOE R&D Accomplishments Database

Gosling, F. G.

1999-01-01

"The Manhattan Project: Making the Atomic Bomb" is a short history of the origins and development of the American atomic bomb program during World War II. Beginning with the scientific developments of the pre-war years, the monograph details the role of the United States government in conducting a secret, nationwide enterprise that took science from the laboratory and into combat with an entirely new type of weapon. The monograph concludes with a discussion of the immediate postwar period, the debate over the Atomic Energy Act of 1946, and the founding of the Atomic Energy Commission.

Chronology of KSC and KSC Related Events for 2012

NASA Technical Reports Server (NTRS)

Liston, Elaine E.

2013-01-01

This 2012 Chronology is published to describe and document KSC's role in NASA's progress. Materials for this Chronology were selected from a number of published sources. The document records KSC events of interest to historians and other researchers. Arrangement is by date of occurrence, though the source cited may be dated one or more days after the event. Materials were researched and compiled for publication by Archivist Elaine Liston.

Chronology of KSC and KSC related events for 1992

NASA Technical Reports Server (NTRS)

Nail, Ken, Jr.

1993-01-01

This chronology is published to fulfill the requirements of KMI 2700.1 to describe and document KSC's role in NASA's progress. Materials for this chronology were selected from a number of published sources. The document records KSC events of interest to historians and other researchers. Arrangement is by date of occurrence, though the source cited may be dated one or more days after the event. An index is included.

Role Playing: The Atomic Bomb and the End of World War II

ERIC Educational Resources Information Center

Eggleston, Noel C.

1978-01-01

Describes how a role playing exercise can be used to teach students in a college level history course about the use of the atomic bomb in World War II. Information is presented on general use of role playing in history courses, objectives, questions to consider about use of the atomic bomb, and course evaluation. For journal availability, see so…

The Tennis Ball Bomb Incident or the Safety Plan as "Shelf Document"

ERIC Educational Resources Information Center

Fast, Jonathan; Fanelli, Rossella

2003-01-01

This article presents a case study of a single incident involving a high school student who brought a "tennis ball" bomb to school. Although the district had recently created a safety plan, with a specific protocol for the discovery of a bomb in the building, the principal and the crises team ignored it. The principal did not refer to…

The cetene scale and the induction period preceding the spontaneous ignition of diesel fuels in bombs

NASA Technical Reports Server (NTRS)

Michailova, M N; Neumann, M B

1936-01-01

In the present report a comparison is made between the scale obtained with mixtures of cetane and l-methyl naphthalene in a bomb, and that obtained with the same fuels in a Waukesha engine. The tests were conducted in a metal bomb heated by a Nichrome spiral. The fuel was injected into the bomb from a Bosch jet by means of a specially constructed plunger pump. The instant injection and the pressure curve in the bomb were registered by a beam of light which was reflected from a mirror connected to the needle of the jet and to a membrane indicator.

Media's role in broadcasting acute stress following the Boston Marathon bombings.

PubMed

Holman, E Alison; Garfin, Dana Rose; Silver, Roxane Cohen

2014-01-07

We compared the impact of media vs. direct exposure on acute stress response to collective trauma. We conducted an Internet-based survey following the Boston Marathon bombings between April 29 and May 13, 2013, with representative samples of residents from Boston (n = 846), New York City (n = 941), and the remainder of the United States (n = 2,888). Acute stress symptom scores were comparable in Boston and New York [regression coefficient (b) = 0.43; SE = 1.42; 95% confidence interval (CI), -2.36, 3.23], but lower nationwide when compared with Boston (b = -2.21; SE = 1.07; 95% CI, -4.31, -0.12). Adjusting for prebombing mental health (collected prospectively), demographics, and prior collective stress exposure, six or more daily hours of bombing-related media exposure in the week after the bombings was associated with higher acute stress than direct exposure to the bombings (continuous acute stress symptom total: media exposure b = 15.61 vs. direct exposure b = 5.69). Controlling for prospectively collected prebombing television-watching habits did not change the findings. In adjusted models, direct exposure to the 9/11 terrorist attacks and the Sandy Hook School shootings were both significantly associated with bombing-related acute stress; Superstorm Sandy exposure wasn't. Prior exposure to similar and/or violent events may render some individuals vulnerable to the negative effects of collective traumas. Repeatedly engaging with trauma-related media content for several hours daily shortly after collective trauma may prolong acute stress experiences and promote substantial stress-related symptomatology. Mass media may become a conduit that spreads negative consequences of community trauma beyond directly affected communities.

Measurements and modeling of contemporary radiocarbon in the stratosphere

NASA Astrophysics Data System (ADS)

Kanu, A. M.; Comfort, L. L.; Guilderson, T. P.; Cameron-Smith, P. J.; Bergmann, D. J.; Atlas, E. L.; Schauffler, S.; Boering, K. A.

2016-02-01

Measurements of the 14C content of carbon dioxide in air collected by high-altitude balloon flights in 2003-2005 reveal the contemporary radiocarbon distribution in the northern midlatitude stratosphere, four decades after the Limited Test Ban Treaty restricted atmospheric testing of nuclear weapons. Comparisons with results from a 3-D chemical-transport model show that the 14CO2 distribution is now largely governed by the altitude/latitude dependence of the natural cosmogenic production rate, stratospheric transport, and propagation into the stratosphere of the decreasing radiocarbon trend in tropospheric CO2 due to fossil fuel combustion. From the observed correlation of 14CO2 with N2O mixing ratios, an annual global mean net flux of 14CO2 to the troposphere of 1.6(±0.4) × 1017‰ mol CO2 yr-1 and a global production rate of 2.2(±0.6) × 1026 atoms 14C yr-1 are empirically derived. The results also indicate that contemporary 14CO2 observations provide highly sensitive diagnostics for stratospheric transport and residence times in models.

Toward unified ice core chronologies with the DatIce tool

NASA Astrophysics Data System (ADS)

Toye Mahamadou Kele, H.; Lemieux-Dudon, B.; Blayo, E.

2012-04-01

Antarctic and Greenland ice cores provide a means to study the phase relationships of climate changes in both hemispheres. They also enable to study the timing between climate, and greenhouse gases or orbital forcings. One key step for such studies is to improve the absolute and relative precisions of ice core age scales (for ice and trapped gas), and beyond that, to try to reach the best consistency between chronologies of paleo records of any kind. The DatIce tool is designed to increase the consistency between pre-existing (also called background) core chronologies. It formulates a variational inverse problem which aims at correcting three key quantities that uniquely define the core age scales: the accumulation rate, the total thinning function, and the close-off depth. For that purpose, it integrates paleo data constraints of many types among which age markers (with for instance documented volcanoes eruptions), and stratigraphic links (with for instance abrupt changes in methane concentration). A cost function is built that enables to calculate new chronologies by making a trade-off between all the constraints (background chronologies and paleo data). The method presented in Lemieux-Dudon et al (2010) has already been applied simultaneously to EPICA EDML and EDC, Vostok and NGRIP. Currently, on going works are conducted at LSCE Saclay and LGGE Grenoble laboratories to construct unified Antarctic chronologies by applying the DatIce tool with new ice cores and new sets of paleo measurements. We here present the DatIce tool, the underlying methodology, and its potential applications. We further show some improvements that have been made recently. We especially adress the issue related to the calibration of the error of pre-existing core chronologies. They are inputs that may have a strong impact on the results. However these uncertainties are uneasy to analyze, since prior chronologies are most of the time assessed on the basis of glaciological models (firn

68Ga/177Lu-NeoBOMB1, a Novel Radiolabeled GRPR Antagonist for Theranostic Use in Oncology.

PubMed

Dalm, Simone U; Bakker, Ingrid L; de Blois, Erik; Doeswijk, Gabriela N; Konijnenberg, Mark W; Orlandi, Francesca; Barbato, Donato; Tedesco, Mattia; Maina, Theodosia; Nock, Berthold A; de Jong, Marion

2017-02-01

Because overexpression of the gastrin-releasing peptide receptor (GRPR) has been reported on various cancer types, for example, prostate cancer and breast cancer, targeting this receptor with radioligands might have a significant impact on staging and treatment of GRPR-expressing tumors. NeoBOMB1 is a novel DOTA-coupled GRPR antagonist with high affinity for GRPR and excellent in vivo stability. The purpose of this preclinical study was to further explore the use of NeoBOMB1 for theranostic application by determining the biodistribution of 68 Ga-NeoBOMB1 and 177 Lu-NeoBOMB1. PC-3 tumor-xenografted BALB/c nu/nu mice were injected with either approximately 13 MBq/250 pmol 68 Ga-NeoBOMB1 or a low (∼1 MBq/200 pmol) versus high (∼1 MBq/10 pmol) peptide amount of 177 Lu-NeoBOMB1, after which biodistribution and imaging studies were performed. At 6 time points (15, 30, 60, 120, 240, and 360 min for 68 Ga-NeoBOMB1 and 1, 4, 24, 48, 96, and 168 h for 177 Lu-NeoBOMB1) postinjection tumor and organ uptake was determined. To assess receptor specificity, additional groups of animals were coinjected with an excess of unlabeled NeoBOMB1. Results of the biodistribution studies were used to determine pharmacokinetics and dosimetry. Furthermore, PET/CT and SPECT/MRI were performed. Injection of approximately 250 pmol 68 Ga-NeoBOMB1 resulted in a tumor and pancreas uptake of 12.4 ± 2.3 and 22.7 ± 3.3 percentage injected dose per gram (%ID/g) of tissue, respectively, at 120 min after injection. 177 Lu-NeoBOMB1 biodistribution studies revealed a higher tumor uptake (17.9 ± 3.3 vs. 11.6 ± 1.3 %ID/g of tissue at 240 min after injection) and a lower pancreatic uptake (19.8 ± 6.9 vs. 105 ± 13 %ID/g of tissue at 240 min after injection) with the higher peptide amount injected, leading to a significant increase in the absorbed dose to the tumor versus the pancreas (200 pmol, 570 vs. 265 mGy/MBq; 10 pmol, 435 vs. 1393 mGy/MBq). Using these data to predict patient dosimetry, we found

Plutonium isotopes offer an alternative approach to establishing chronological profiles in coarse sediments

NASA Astrophysics Data System (ADS)

Pondell, C.; Kuehl, S. A.; Canuel, E. A.

2016-12-01

There are several methodologies used to determine chronologies for sediments deposited within the past 100 years, including 210Pb and 137Cs radioisotopes and organic and inorganic contaminants. These techniques are quite effective in fine sediments, which generally have a high affinity for metals and organic compounds. However, the application of these chronological tools becomes limited in systems where coarse sediments accumulate. Englebright Lake is an impoundment in northern California where sediment accumulation is characterized by a combination of fine and coarse sediments. This combination of sediment grain size complicated chronological analysis using the more traditional 137Cs chronological approach. This study established a chronology of these sediments using 239+240Pu isotopes. While most of the 249+240Pu activity was measured in the fine grain size fraction (<63 microns), up to 25% of the plutonium activity was detected in the coarse size fractions of sediments from Englebright Lake. Profiles of 239+240Pu were similar to available 137Cs profiles, verifying the application of plutonium isotopes for determining sediment chronologies and expanding the established geochronology for Englebright Lake sediments. This study of sediment accumulation in Englebright Lake demonstrates the application of plutonium isotopes in establishing chronologies in coarse sediments and highlights the potential for plutonium to offer new insights into patterns of coarse sediment accumulation.

Rapid intercontinental air pollution transport associated with a meteorological bomb

NASA Astrophysics Data System (ADS)

Stohl, A.; Huntrieser, H.; Richter, A.; Beirle, S.; Cooper, O. R.; Eckhardt, S.; Forster, C.; James, P.; Spichtinger, N.; Wenig, M.; Wagner, T.; Burrows, J. P.; Platt, U.

2003-07-01

Intercontinental transport (ICT) of trace substances normally occurs on timescales ranging from a few days to several weeks. In this paper an extraordinary episode in November 2001 is presented, where pollution transport across the North Atlantic took only about one day. The transport mechanism, termed here an intercontinental pollution express highway because of the high wind speeds, was exceptional, as it involved an explosively generated cyclone, a so-called meteorological "bomb''. To the authors' knowledge, this is the first study describing pollution transport in a bomb. The discovery of this event was based on tracer transport model calculations and satellite measurements of NO2, a species with a relatively short lifetime in the atmosphere, which could be transported that far only because of the high wind speeds produced by the bomb. A 15-year transport climatology shows that intercontinental express highways are about four times more frequent in winter than in summer, in agreement with bomb climatologies. The climatology furthermore suggests that intercontinental express highways may be important for the budget of short-lived substances in the remote troposphere. For instance, for a substance with a lifetime of 1 day, express highways may be responsible for about two thirds of the total ICT. We roughly estimate that express highways connecting North America with Europe enhance the average NOx mixing ratios over Europe, due to North American emissions, by about 2-3 pptv in winter.

Monitoring exposure to atomic bomb radiation by somatic mutation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akiyama, Mitoshi; Kyoizumi, Seishi; Kusunoki, Yoichiro

Atomic bomb survivors are a population suitable for studying the relationship between somatic mutation and cancer risk because their exposure doses are relatively well known and their dose responses in terms of cancer risk have also been thoroughly studied. An analysis has been made of erythrocyte glycophorin A (GPA) gene mutations in 1,226 atomic bomb survivors in Hiroshima and Nagasaki. The GPA mutation frequency (Mf) increased slightly but significantly with age at the time of measurement and with the number of cigarettes smoked. After adjustment for the effect of smoking, the Mf was significantly higher in males than in femalesmore » and higher in Hiroshima than in Nagasaki. All of these characteristics of the background GPA Mf were in accord with those of solid tumor incidence obtained from an earlier epidemiological study of A-bomb survivors. Analysis of the dose effect on Mf revealed the doubling dose to be about 1.20 Sv and the minimum dose for detection of a significant increase to be about 0.24 Sv. No significant dose effect for difference in sex, city, or age at the time of bombing was observed. Interestingly, the doubling dose for the GPA Mf approximated that for solid cancer incidence (1.59 Sv). And the minimum dose for detection was not inconsistent with the data for solid cancer incidence. The dose effect was significantly higher in those diagnosed with cancer before or after measurement than in those without a history of cancer. These findings are consistent with the hypothesis that somatic mutations are the main cause of excess cancer risk from radiation exposure. 27 refs., 2 figs.« less

Cancer mortality among atomic bomb survivors exposed as children.

PubMed

Goto, Hitomi; Watanabe, Tomoyuki; Miyao, Masaru; Fukuda, Hiromi; Sato, Yuzo; Oshida, Yoshiharu

2012-05-01

To compare cancer mortality among A-bomb survivors exposed as children with cancer mortality among an unexposed control group (the entire population of Japan, JPCG). The subjects were the Hiroshima and Nagasaki A-bomb survivor groups (0-14 years of age in 1945) reported in life span study report 12 (follow-up years were from 1950 to 1990), and a control group consisting of the JPCG. We estimated the expected number of deaths due to all causes and cancers of various causes among the exposed survivors who died in the follow-up interval, if they had died with the same mortality as the JPCG (0-14 years of age in 1945). We calculated the standardized mortality ratio (SMR) of A-bomb survivors in comparison with the JPCG. SMRs were significantly higher in exposed boys overall for all deaths, all cancers, leukemia, and liver cancer, and for exposed girls overall for all cancers, solid cancers, liver cancer, and breast cancer. In boys, SMRs were significantly higher for all deaths and liver cancer even in those exposed to very low doses, and for all cancers, solid cancers, and liver cancer in those exposed to low doses. In girls, SMRs were significantly higher for liver cancer and uterine cancer in those exposed to low doses, and for leukemia, solid cancers, stomach cancer, and breast cancer in those exposed to high doses. We calculated the SMRs for the A-bomb survivors versus JPCG in childhood and compared them with a true non-exposed group. A notable result was that SMRs in boys exposed to low doses were significantly higher for solid cancer.

An A. S. Neill/Summerhill Chronology.

ERIC Educational Resources Information Center

Matthias, William

1980-01-01

This chronology of the life of Alexander Sutherland Neill, headmaster of Summerhill School, details each year of his life from 1883 to 1973. The author of 21 books, Neill did not espouse a return to "basics" in education. (JN)

Preparation of bone samples in the Gliwice Radiocarbon Laboratory for AMS radiocarbon dating.

PubMed

Piotrowska, N; Goslar, T

2002-12-01

In the Gliwice Radiocarbon Laboratory, a system for preparation of samples for AMS dating has been built. At first it was used to produce graphite targets from plant macrofossils and sediments. In this study we extended its capabilities with the preparation of bones. We dealt with 3 methods; the first was the classical Longin method of collagen extraction, the second one included additional treatment of powdered bone in alkali solution, while in the third one carboxyl carbon was separated from amino acids obtained after hydrolysis of protein. The suitability of the methods was tested on 2 bone samples. Most of our samples gave ages > 40 kyr BP, suggesting good performance of the adapted methods, except for one sample prepared with simple Longin method. For routine preparation of bones we chose the Longin method with additional alkali treatment.

Design, Development, and Innovation of an Interactive Multimedia Training Simulator for Responding to Air Transportation Bomb Threats

NASA Technical Reports Server (NTRS)

Chung, Christopher A.; Marwaha, Shweta

2005-01-01

This paper describes an interactive multimedia simulator for air transportation bomb threat training. The objective of this project is to improve the air transportation sector s capability to respond to bomb threats received by commercial airports and aircraft. The simulator provides realistic training on receiving and responding to a variety of bomb threats that might not otherwise be possible due to time, cost, or operational constraints. Validation analysis indicates that the use of the simulator resulted in statistically significant increases in individual ability to respond to these types of bomb threats.

Soil organic matter stability as indicated by compound-specific radiocarbon analyses

NASA Astrophysics Data System (ADS)

van der Voort, Tessa Sophia; Zell, Claudia; Hagedorn, Frank; McIntyre, Cameron; Eglinton, Timothy Ian

2017-04-01

Carbon storage in soils is increasingly recognized as a key ecosystem function, and molecular-level analyses could be a valuable potential indicator of this storage potential. In this framework, radiocarbon constitutes a powerful tool for unraveling soil carbon dynamics on both decadal as well as centennial and millennial timescales. In this study, we look at the radiocarbon signature of specific compounds (fatty acids and n-alkanes) in two forested ecosystems (temperate and pre-alpine) with the aim of attaining a better understanding of soil organic carbon stability on a molecular level. Radiocarbon dating of the fatty acids and n-alkanes has been coupled to abundance data of these compounds and additionally lignin phenols. We hypothesize that potentially, these long-chain apolar compounds could be a representative indicator of the mineral-bound soil organic carbon pool. These well-studied sites are part of the Long-Term Forest Ecosystem Research (LWF) program of the Swiss Federal Institute for Forest, Snow and Landscape research (WSL). Therefore, a wide suite of ancillary climatic and textural data is available for these sites. Initial results show a wide range of ages in the specific compounds which constitute a much larger range than the ages indicated by the density fractions done on the same samples. Overall, this study explores the use of molecular-level indicators to study soil organic matter dynamics, which could help assess the overall potential vulnerability of soil carbon in various ecosystems.

Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

NASA Astrophysics Data System (ADS)

Salehpour, M.; Håkansson, K.; Possnert, G.; Wacker, L.; Synal, H.-A.

2016-03-01

A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV 14,13,12C3+ ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the 14C/12C and the 13C/12C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

Radiocarbon constraints on the glacial ocean circulation and its impact on atmospheric CO2

PubMed Central

Skinner, L. C.; Primeau, F.; Freeman, E.; de la Fuente, M.; Goodwin, P. A.; Gottschalk, J.; Huang, E.; McCave, I. N.; Noble, T. L.; Scrivner, A. E.

2017-01-01

While the ocean’s large-scale overturning circulation is thought to have been significantly different under the climatic conditions of the Last Glacial Maximum (LGM), the exact nature of the glacial circulation and its implications for global carbon cycling continue to be debated. Here we use a global array of ocean–atmosphere radiocarbon disequilibrium estimates to demonstrate a ∼689±53 14C-yr increase in the average residence time of carbon in the deep ocean at the LGM. A predominantly southern-sourced abyssal overturning limb that was more isolated from its shallower northern counterparts is interpreted to have extended from the Southern Ocean, producing a widespread radiocarbon age maximum at mid-depths and depriving the deep ocean of a fast escape route for accumulating respired carbon. While the exact magnitude of the resulting carbon cycle impacts remains to be confirmed, the radiocarbon data suggest an increase in the efficiency of the biological carbon pump that could have accounted for as much as half of the glacial–interglacial CO2 change. PMID:28703126

Radiocarbon constraints on the glacial ocean circulation and its impact on atmospheric CO2

NASA Astrophysics Data System (ADS)

Skinner, L. C.; Primeau, F.; Freeman, E.; de La Fuente, M.; Goodwin, P. A.; Gottschalk, J.; Huang, E.; McCave, I. N.; Noble, T. L.; Scrivner, A. E.

2017-07-01

While the ocean's large-scale overturning circulation is thought to have been significantly different under the climatic conditions of the Last Glacial Maximum (LGM), the exact nature of the glacial circulation and its implications for global carbon cycling continue to be debated. Here we use a global array of ocean-atmosphere radiocarbon disequilibrium estimates to demonstrate a ~689+/-53 14C-yr increase in the average residence time of carbon in the deep ocean at the LGM. A predominantly southern-sourced abyssal overturning limb that was more isolated from its shallower northern counterparts is interpreted to have extended from the Southern Ocean, producing a widespread radiocarbon age maximum at mid-depths and depriving the deep ocean of a fast escape route for accumulating respired carbon. While the exact magnitude of the resulting carbon cycle impacts remains to be confirmed, the radiocarbon data suggest an increase in the efficiency of the biological carbon pump that could have accounted for as much as half of the glacial-interglacial CO2 change.

Hurricane Ike versus an Atomic Bomb

ERIC Educational Resources Information Center

Pearson, Earl F.

2013-01-01

The destructive potential of one of nature's most destructive forces, the hurricane, is compared to one of human's most destructive devices, an atomic bomb. Both can create near absolute devastation at "ground zero". However, how do they really compare in terms of destructive energy? This discussion compares the energy, the…

Evenness indices measure the signal strength of biweight site chronologies

Treesearch

Kurt H. Riitters

1990-01-01

The signal strength of a biweight site chronology is properly viewed as an outcome of analysis rather than as a property of the forest-climate system. It can be estimated by the evenness of the empirical weights that are assigned to individual trees. The approach is demonstrated for a 45-year biweight chronology obtained from 40 jack pine (Pinus banksiana Lamb.) trees...

AMS radiocarbon investigation of the African baobab: Searching for the oldest tree

NASA Astrophysics Data System (ADS)

Patrut, Adrian; von Reden, Karl F.; Mayne, Diana H.; Lowy, Daniel A.; Patrut, Roxana T.

2013-01-01

The Glencoe baobab, a very large specimen from South Africa, split twice in 2009. Several wood samples were collected from the eastern cavity, from the outer part of the main section and also from the largest broken segment which was connected to this section. These wood samples were processed and investigated by AMS radiocarbon dating. The radiocarbon date of the oldest sample was found to be 1838 ± 21 BP, which corresponds to a calibrated age of 1835 ± 40 years. Thus, the Glencoe baobab becomes the oldest dated baobab and also the oldest angiosperm tree with accurate dating results. The distribution of dating results revealed that the Glencoe baobab is a multi-generation tree, with several standing or collapsed and partially fused stems, showing different ages.

Physical injuries and fatalities resulting from the Oklahoma City bombing.

PubMed

Mallonee, S; Shariat, S; Stennies, G; Waxweiler, R; Hogan, D; Jordan, F

1996-08-07

To provide an epidemiologic description of physical injuries and fatalities resulting from the April 19, 1995, bombing of the Alfred P. Murrah Federal Building in Oklahoma City. Descriptive epidemiologic study of all persons injured by the bombing and of all at-risk occupants of the federal building and 4 adjacent buildings. Data were gathered from hospital emergency and medical records departments, medical examiner records, and surveys of area physicians, building occupants, and survivors. All persons known to have been exposed to the blast. Characteristics of fatalities and injuries, injury maps, and injury rates by building location. A total of 759 persons sustained injuries, 167 persons died, 83 survivors were hospitalized, and 509 persons were treated as outpatients. Of the 361 persons who were in the federal building, 319 (88%) were injured, of whom 163 (45%) died, including 19 children. Persons in the collapsed part of the federal building were significantly more likely to die (153/175, 87%) than those in other parts of the building (10/186, 5%) (risk ratio [RR], 16.3; 95% confidence interval [CI], 8.9-29.8). In 4 adjacent buildings, injury rates varied from 38% to 100%; 3 persons in these buildings and 1 person in an outdoor location died. The most frequent cause of death was multiple injuries. Among survivors, soft tissue injuries, fractures, sprains, strains, and head injuries were most common; these injuries were most often caused by flying glass and other debris and collapsed ceilings. The Oklahoma City bombing resulted in the largest number of fatalities of any terrorist act in the United States, and there were 4 times as many nonfatal injuries as fatalities. Disaster management plans should include the possibility of terrorist bombing, and medical preparedness should anticipate that most injuries will be nonfatal. The role of building collapse in fatal injuries should be considered in the design of buildings at high risk of being bombed so as to

BDA: Anglo-American Air Intelligence, Bomb Damage Assessment, and the Bombing Campaigns Against Germany, 1914-1945

DTIC Science & Technology

2005-05-19

air intelligence personnel to construct the rest of the story based on their expertise, experience, and intuition. Once again, Clausewitz proved...after firing," indicating the importance of obtaining useful photointelligence for construction of artillery and bomb damage assessments.31 This...quality, single-body construction , which gave manufacturers trouble until late 1918.69 The degree to which the evolution of aerial bombardment in

BIOGENIC CONTRIBUTION TO PM-2.5 AMBIENT AEROSOL FROM RADIOCARBON MEASUREMENTS

EPA Science Inventory

Knowledge of the relative contributions of biogenic versus anthropogenic sources to ambient aerosol is of great interest in the formulation of strategies to achieve nationally mandated air quality standards. Radiocarbon (Carbon-14) measurements provide a means to quantify the ...

Dating Studies of Elephant Tusks Using Accelerator Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sideras-Haddad, E; Brown, T A

A new method for determining the year of birth, the year of death, and hence, the age at death, of post-bomb and recently deceased elephants has been developed. The technique is based on Accelerator Mass Spectrometry radiocarbon analyses of small-sized samples extracted from along the length of a ge-line of an elephant tusk. The measured radiocarbon concentrations in the samples from a tusk can be compared to the {sup 14}C atmospheric bomb-pulse curve to derive the growth years of the initial and final samples from the tusk. Initial data from the application of this method to two tusks will bemore » presented. Potentially, the method may play a significant role in wildlife management practices of African national parks. Additionally, the method may contribute to the underpinnings of efforts to define new international trade regulations, which could, in effect, decrease poaching and the killing of very young animals.« less

Using 50 years of soil radiocarbon data to identify optimal approaches for estimating soil carbon residence times

NASA Astrophysics Data System (ADS)

Baisden, W. T.; Canessa, S.

2013-01-01

In 1959, Athol Rafter began a substantial programme of systematically monitoring the flow of 14C produced by atmospheric thermonuclear tests through organic matter in New Zealand soils under stable land use. A database of ∼500 soil radiocarbon measurements spanning 50 years has now been compiled, and is used here to identify optimal approaches for soil C-cycle studies. Our results confirm the potential of 14C to determine residence times, by estimating the amount of ‘bomb 14C’ incorporated. High-resolution time series confirm this approach is appropriate, and emphasise that residence times can be calculated routinely with two or more time points as little as 10 years apart. This approach is generally robust to the key assumptions that can create large errors when single time-point 14C measurements are modelled. The three most critical assumptions relate to: (1) the distribution of turnover times, and particularly the proportion of old C (‘passive fraction’), (2) the lag time between photosynthesis and C entering the modelled pool, (3) changes in the rates of C input. When carrying out approaches using robust assumptions on time-series samples, multiple soil layers can be aggregated using a mixing equation. Where good archived samples are available, AMS measurements can develop useful understanding for calibrating models of the soil C cycle at regional to continental scales with sample numbers on the order of hundreds rather than thousands. Sample preparation laboratories and AMS facilities can play an important role in coordinating the efficient delivery of robust calculated residence times for soil carbon.

The association between chronic kidney disease and cardiovascular disease risk factors in atomic bomb survivors.

PubMed

Sera, Nobuko; Hida, Ayumi; Imaizumi, Misa; Nakashima, Eiji; Akahoshi, Masazumi

2013-01-01

Atomic bomb (A-bomb) radiation is associated with cardiovascular disease (CVD) and metabolic CVD risk factors. Chronic kidney disease (CKD) is also known to be a risk factor for CVD and little is known whether CKD is associated with A-bomb radiation. To examine whether CKD is associated with CVD risk factors or with A-bomb radiation in A-bomb survivors, we classified renal dysfunction in 1,040 A-bomb survivors who were examined in 2004-2007 as normal [n = 121; estimated glomerular filtration rate (eGFR) ≥ 90 ml/min/1.73 m(2)]; mild (n = 686; eGFR 60-89 ml/min/1.73 m(2)); moderate (n = 217; eGFR 30-59 ml/min/1.73 m(2)); or severe (n = 16; eGFR <30 ml/min/1.73 m(2)). Also, we diagnosed subjects in the moderate and severe renal dysfunction groups as having CKD (n = 233; eGFR <59 ml/min/1.73 m(2)). After adjusting for age, gender, and smoking and drinking habits, we looked for an association between renal dysfunction and hypertension, diabetes mellitus (DM), hyperlipidemia, and metabolic syndrome (MetS), and between renal dysfunction and A-bomb radiation. Hypertension [odds ratio (OR), 1.57; 95% confidence interval (CI), 1.12-2.20, P = 0.009]; DM (OR, 1.79; 95% CI, 1.23-2.61, P = 0.002); hyperlipidemia (OR, 1.55; 95% CI, 1.12-2.14, P = 0.008); and MetS (OR, 1.86; 95% CI, 1.32-2.63, P < 0.001) were associated with CKD (moderate/severe renal dysfunction), and hyperlipidemia and MetS were also associated with mild renal dysfunction. CKD (OR/Gy, 1.29; 95% CI, 1.01-1.63, P = 0.038) and severe renal dysfunction (OR/Gy, 3.19; 95% CI, 1.63-6.25, P < 0.001) were significantly associated with radiation dose. CKD associated with radiation may have played a role in the development of CVD among A-bomb survivors.

Terrorist bombings. Lessons learned from Belfast to Beirut.

PubMed Central

Frykberg, E R; Tepas, J J

1988-01-01

Experience in the management of mass casualties following a disaster is relatively sparse. The terrorist bombing serves as a timely and effective model for the analysis of patterns of injury and mortality and the determination of the factors influencing casualty survival in the wake of certain forms of disaster. For this purpose, a review of the published experience with terrorist bombings was carried out, providing a study population of 3357 casualties from 220 incidents worldwide. There were 2934 immediate survivors of these incidents (87%), of whom 881 (30%) were hospitalized. Forty deaths ultimately occurred among these survivors (1.4%), 39 of whom were among those hospitalized (4.4%). Injury severity was determined from available data for 1339 surviving casualties, 251 of whom were critically injured (18.7%). Of this population evaluable for injury severity, there were 31 late deaths, all of which occurred among those critically injured, accounting for an overall "critical mortality" rate of 12.4%. Overall triage efficiency was characterized by a mean overtriage rate (noncritically injured among those hospitalized or evacuated) of 59%, and a mean undertriage rate (critically injured among those not hospitalized or evacuated) of .05%. Multiple linear regression analysis of all major bombing incidents demonstrated a direct linear relationship between overtriage and critical mortality (r2 = .845), and an inversely proportional relationship between triage discrimination and critical mortality (r2 = 0.855). Although head injuries predominated in both immediate (71%) and late (52%) fatalities, injury to the abdomen carried the highest specific mortality rate (19%) of any single body system injury among immediate survivors. These data clearly document the importance of accurate triage as a survival determinant for critically injured casualties of these disasters. Furthermore, the data suggest that explosive force, time interval from injury to treatment, and anatomic

Patenting the bomb: nuclear weapons, intellectual property, and technological control.

PubMed

Wellerstein, Alex

2008-03-01

During the course of the Manhattan Project, the U.S. government secretly attempted to acquire a monopoly on the patent rights for inventions used in the production of nuclear weapons and nuclear energy. The use of patents as a system of control, while common for more mundane technologies, would seem at first glance to conflict with the regimes of secrecy that have traditionally been associated with nuclear weapons. In explaining the origins and operations of the Manhattan Project patent system, though, this essay argues that the utilization of patents was an ad hoc attempt at legal control of the atomic bomb by Manhattan Project administrators, focused on the monopolistic aspects of the patent system and preexisting patent secrecy legislation. From the present perspective, using patents as a method of control for such weapons seems inadequate, if not unnecessary; but at the time, when the bomb was a new and essentially unregulated technology, patents played an important role in the thinking of project administrators concerned with meaningful postwar control of the bomb.

Expanding the network of crossdated tree-ring chronologies for Sequoia sempervirens

Treesearch

Allyson L. Carroll; Stephen C. Sillett; Ethan J. Coonen; Benjamin G. Iberle

2017-01-01

Crossdated tree-ring chronologies for the Arcata Community Forest (ACF) and Muir Woods National Monument (Muir Woods) expand the spatial coverage of dated coast redwood (Sequoia sempervirens (D. Don) Endl.) series. Crossdating relies on the common pattern of ring-width variation among tree populations, and dated chronologies have many applications...

FROM THE HISTORY OF PHYSICS: The development of the first Soviet atomic bomb

NASA Astrophysics Data System (ADS)

Goncharov, German A.; Ryabev, Lev D.

2001-01-01

In the late 1930s and early 1940s, two remarkable physical phenomena — the fission of heavy nuclei and the chain fission reaction — were discovered, implying that a new powerful source of energy (nuclear fission energy) might become a practical possibility for mankind. At that time, however, the political situation in the world made the development of the atomic bomb the main objective of nuclear energy research in the countries involved. The first atomic bombs, notoriously used in the war against Japan, were produced by the United States of America only six and a half years after the discovery of fission. Four years later, the first Soviet atomic bomb was tested. This was a major step toward the establishment of nuclear parity which led to stability and global peace and thus greatly influenced the destiny of human kind. Based on documentary materials covering the period from 1939 to 1949, this paper traces the origin and evolution of the physical ideas behind the first Soviet atomic bomb and discusses the most important events associated with the project.

ELLERMAN BOMBS AT HIGH RESOLUTION. IV. VISIBILITY IN Na I AND Mg I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rutten, R. J.; Rouppe van der Voort, L. H. M.; Vissers, G. J. M., E-mail: R.J.Rutten@uu.nl

2015-08-01

Ellerman bombs are transient brightenings of the wings of the solar Balmer lines that mark reconnection in the photosphere. Ellerman noted in 1917 that he did not observe such brightenings in the Na i D and Mg i b lines. This non-visibility should constrain EB interpretation, but has not been addressed in published bomb modeling. We therefore test Ellerman’s observation and confirm it using high-quality imaging spectrometry with the Swedish 1-m Solar Telescope. However, we find a diffuse brightness in these lines that seems to result from prior EBs. We tentatively suggest this is a post-bomb hot-cloud phenomenon also foundmore » in recent EB spectroscopy in the ultraviolet.« less

Precision closed bomb calorimeter for testing flame and gas producing initiators

NASA Technical Reports Server (NTRS)

Carpenter, D. R., Jr.; Taylor, A. C., Jr.

1972-01-01

A calorimeter has been developed under this study to help meet the needs of accurate performance monitoring of electrically or mechanically actuated flame and gas producing devices, such as squib-type initiators. A ten cubic centimeter closed bomb (closed volume) calorimeter was designed to provide a standard pressure trace and to measure a nominal 50 calorie output, using the basic components of a Parr Model 1411 calorimeter. Two prototype bombs were fabricated, pressure tested to 2600 psi, and extensively evaluated.

A Chronological History of Puerto Rico.

ERIC Educational Resources Information Center

Tovar, Federico Ribes

This book presents a chronological history of Puerto Rico from prehistory and discovery through December of 1972. It includes information on the persons and events that influenced the course of Puerto Rican history. A table of contents and a selective index are included. (Author/AM)

School Attendance Patterns, Unmet Educational Needs, and Truancy: A Chronological Perspective

ERIC Educational Resources Information Center

Spencer, Andrea M.

2009-01-01

This study examines chronological patterns of attendance and academic performance of urban students who are identified as truants in Grade 8. A chronological review of 42 student records, from school entry through Grade 8, identified high frequencies of absenteeism and academic performance issues beginning at school entry and, in many cases,…

RADIOCARBON MEASUREMENTS ON PM 2.5 AMBIENT AEROSOL FROM NASHVILLE, TN

EPA Science Inventory

Radiocarbon (Carbon-14) measurements provide an estimate of the fraction of carbon in a sample that is biogenic. The methodology has been extensively used in past wintertime studies to quantify the contribution of wood smoke to ambient aerosol. In summertime such measurements...

33 CFR 334.60 - Cape Cod Bay south of Wellfleet Harbor, Mass.; naval aircraft bombing target area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Harbor, Mass.; naval aircraft bombing target area. 334.60 Section 334.60 Navigation and Navigable Waters... REGULATIONS § 334.60 Cape Cod Bay south of Wellfleet Harbor, Mass.; naval aircraft bombing target area. (a... bombing target hulk James Longstreet in Cape Cod Bay at latitude 41°49′46″, longitude 70°02′54″. (b) The...

33 CFR 334.60 - Cape Cod Bay south of Wellfleet Harbor, Mass.; naval aircraft bombing target area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Harbor, Mass.; naval aircraft bombing target area. 334.60 Section 334.60 Navigation and Navigable Waters... REGULATIONS § 334.60 Cape Cod Bay south of Wellfleet Harbor, Mass.; naval aircraft bombing target area. (a... bombing target hulk James Longstreet in Cape Cod Bay at latitude 41°49′46″, longitude 70°02′54″. (b) The...

Analytic treatment of the black-hole bomb

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hod, Shahar; Hod, Oded; School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978

2010-03-15

A bosonic field impinging on a rotating black hole can be amplified as it scatters off the hole, a phenomenon known as superradiant scattering. If in addition the field has a nonzero rest mass {mu}, the mass term effectively works as a mirror, reflecting the scattered wave back towards the black hole. In this physical system, known as a black-hole bomb, the wave may bounce back and forth between the black hole and some turning point, amplifying itself each time. Consequently, the field grows exponentially over time and is unstable. In this paper we study analytically for the first timemore » the phenomenon of superradiant instability (the black-hole bomb mechanism) in the regime M{mu}=O(1) of greatest instability. We find a maximal instability growth rate of {tau}{sup -1}=1.7x10{sup -3}M{sup -1}. This instability is 4 orders of magnitude stronger than has been previously estimated.« less

Examining Changing American Perceptions of the Terrorist Threat: From the Oklahoma City Bombing to Al Qaeda

DTIC Science & Technology

2017-12-01

CHANGING AMERICAN PERCEPTIONS OF THE TERRORIST THREAT: FROM THE OKLAHOMA CITY BOMBING TO AL QAEDA by Eli U.S. Persons December 2017 Thesis...THREAT: FROM THE OKLAHOMA CITY BOMBING TO AL QAEDA 5. FUNDING NUMBERS 6. AUTHOR(S) Eli U.S. Persons 7. PERFORMING ORGANIZATION NAME(S) AND...THREAT: FROM THE OKLAHOMA CITY BOMBING TO AL QAEDA Eli U.S. Persons Major, United States Air Force B.S., United States Air Force Academy, 2005

Comparison of post-disaster psychiatric disorders after terrorist bombings in Nairobi and Oklahoma City.

PubMed

North, Carol S; Pfefferbaum, Betty; Narayanan, Pushpa; Thielman, Samuel; McCoy, Gretchen; Dumont, Cedric; Kawasaki, Aya; Ryosho, Natsuko; Kim, You-Seung; Spitznagel, Edward L

2005-06-01

African disaster-affected populations are poorly represented in disaster mental health literature. To compare systematically assessed mental health in populations directly exposed to terrorist bombing attacks on two continents, North America and Africa. Structured diagnostic interviews compared citizens exposed to bombings of the US Embassy in Nairobi, Kenya (n=227) and the Oklahoma City Federal Building (n=182). Prevalence rates of post-traumatic stress disorder (PTSD) and major depression were similar after the bombings. No incident (new since the bombing) alcohol use disorders were observed in either site. Symptom group C was strongly associated with PTSD in both sites. The Nairobi group relied more on religious support and the Oklahoma City group used more medical treatment, drugs and alcohol. Post-disaster psychopathology had many similarities in the two cultures; however, coping responses and treatment were quite different. The findings suggest potential for international generalisability of post-disaster psychopathology, but confirmatory studies are needed.

A High-Resolution Chronology of Rapid Forest Transitions following Polynesian Arrival in New Zealand

PubMed Central