How robust is the pre-1931 National Climatic Data Center—climate divisional dataset? Examples from Georgia and Louisiana     

Jason Allard  Clint Thompson  Barry D. Keim 《Theoretical and Applied Climatology》2015,120(1-2):323-330

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Variability of rainfall from tropical cyclones in the eastern USA and its association to the AMO and ENSO   总被引：1，自引：0，他引：1  

Ricardo C. Nogueira  Barry D. Keim  David P. Brown  Kevin D. Robbins 《Theoretical and Applied Climatology》2013,112(1-2):273-283

Tropical cyclone (TC) rainfall along the eastern USA exhibits a high degree of variability with the potential to produce precipitation amounts in excess of 100 % of the annual mean at locations ranging from the immediate coastline to hundreds of kilometers inland. However, the spatiotemporal distribution of TC rainfall variability has not yet been fully characterized for this region, particularly with regard to large-scale climate teleconnections (e.g., El Nino-Southern Oscillation (ENSO) and Atlantic multidecadal oscillation (AMO)). The objectives of this study are to (1) assess temporal variability and trends in TC rainfall since 1960, and (2) characterize the spatial variability of TC rainfall during varying AMO and ENSO regimes. Kendall tau-b analysis highlighted the presence of statistically significant positive trends in TC rainfall at a number of locations. Principal components analysis revealed that AMO exhibited significant linkages to TC rainfall in northern New England as well as along the US Gulf Coast, while ENSO was most strongly linked to TC variability in Texas. Results illustrate the varied nature of TC rainfall across the eastern USA and the complex linkages to large-scale climate mechanisms at interannual and decadal time scales.  相似文献   

Cretaceous and Cenozoic cooling history across the ultrahigh pressure Tongbai–Dabie belt, central China, from apatite fission-track thermochronology     

Shengbiao Hu  Barry P. Kohn  Asaf Raza  Jiyang Wang  Andrew J.W. Gleadow 《Tectonophysics》2006,420(3-4):409-429

The crystalline terrane of the Tongbai–Dabie region, central China, comprising the Earth's largest ultrahigh-pressure (UHP) exposure was formed during Triassic collision between the Sino–Korean and Yangtze cratons. New apatite fission-track (AFT) data presented here from the UHP terrane, extends over a significantly greater area than reported in previous studies, and includes the (eastern) Dabie, the Hong'an (northwestern Dabie) and Tongbai regions. The new data yield ages ranging from 44 ± 3 to 142 ± 36 Ma and mean track lengths between 10 and 14.4 μm. Thermal history models based on the AFT data taken together with published ⁴⁰Ar/³⁹Ar, K–Ar, apatite and zircon (U–Th)/He and U–Pb data, exhibit a three-stage cooling pattern that is similar across the study region, commencing with an Early Cretaceous rapid cooling event, followed by a period of relative thermal stability during which rocks remained at temperatures within the AFT partial annealing zone (60–110 °C) and ending with a possible renewed phase of accelerated cooling during Pliocene to Recent time. The first cooling phase followed large-scale transtensional deformation between 140 and 110 Ma and is related to Early Cretaceous eastward tectonic escape and Pacific back arc extension. Between this phase and the subsequent slow cooling phase, a transition period from 120 to 80 Ma (to 70 to 45 Ma along the Tan–Lu fault) was characterised by a relatively low cooling rate (3–5 °C/Ma). This transition is likely related to a tectonic response associated with the mid-Cretaceous subduction of the Izanagi–Pacific plate as well as lithospheric extension and thinning in eastern Asia. The present regional AFT age pattern is therefore basically controlled by the Early Cretaceous rapid cooling event, but finally shaped through active Cenozoic faulting. Following the transition phase the subsequent slow cooling phase pattern implies a net reduction in horizontal compressional stress corresponding to increased extension rates along the continental margin due to the decrease in plate convergence. Modelling of the AFT data suggests a possible Pliocene–Recent cooling episode, which may be supported by increased rates of sedimentation observed in adjacent basins. This cooling phase may be interpreted as a response to the far-field effects of the frontal India–Eurasia collision to the west. Approximate estimates suggest that the total amount of post 120 Ma denudation across the UHP orogen ranged from 2.4 to 13.2 km for different tectonic blocks and ranged from 0.8 to 9.7 km during the Cretaceous to between 1.7 and 3.8 km during the Cenozoic.  相似文献   

Mapping the archaeological soil archive of sand and gravel mineral reserves in Britain     

Ingrid Ward  Barry Smith  Russell Lawley 《Geoarchaeology》2009,24(1):1-21

Primary sand and gravel deposits in Britain play an important role in preserving our cultural heritage and are also a valuable aggregate resource. While an understanding of the extrinsic properties of the soil archive (such as pH, redox, groundwater) can provide a firstorder assessment of the potential risk to any archaeologically sensitive deposits, we have very poor definition of spatial variations in the extrinsic properties of soil that influence archaeological preservation at a regional and national scale. Developments in digital geological mapping, remote sensing, and geochemical survey data undertaken by the British Geological Survey (BGS) have, however, significantly extended capabilities in this respect and can potentially be used to provide a primary assessment of the sensitivity of the present soil archive and the potential risk from changes to the soil process on cultural material in areas earmarked for aggregate extraction. Two of the major factors affecting archaeological preservation—soil acidification and groundwater—can be mapped or predicted at scales of better than 1:50,000 across increasingly large parts of the country using a combination of regional hydrogeological, geophysical, and geochemical data. Additional data from site investigations may further refine preservation potential as a function of changes in redox potential and acidity. These data, maps and models can be used to (1) better establish a baseline for archaeological preservation at a regional and national scale and (2) improve our understanding of how the physical and chemical properties of the near surface environment can be managed to sustainably preserve archaeological materials in areas impacted by sand and gravel extraction. © 2009 Wiley Periodicals, Inc.  相似文献   

Age of the Alaşehir graben (West Turkey) and its tectonic implications     

Gürol Seyitolu  Barry C. Scott 《Geological Journal》1996,31(1):1-11

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