International list of geographical serials | C.D. Harris and J.D. Fellmann (Editors), 1980. Third edition, 1980, by J.D. Harris and D. Fellmann, 457 pp., U.S. $8.00, $6.00 by series subscr. Fourth edition, 1980, by C.D. Harris, 164 pp., U.S. $8.00, $6.00 by series subscr. Department of Geography,University of Chicago,Chicago, Ill.     

Malcolm G. Anderson 《Earth》1981,17(3):313-314

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Functional attributes of epilithic diatoms for palaeoenvironmental interpretations in South-West Greenland lakes     

Suzanne McGowan  Hazel V. Gunn  Erika J. Whiteford  N. John Anderson  Vivienne J. Jones  Antonia C. Law 《Journal of Paleolimnology》2018,60(2):273-298

Benthic diatoms are commonly used for palaeoenvironmental reconstruction in Arctic regions, but interpretation of their ecology remains challenging. We studied epilithic diatom assemblages from the shallow margins of 19 lakes from three areas (coast-inland-ice sheet margin) along a climate gradient in Kangerlussuaq, West Greenland during two periods; shortly after ice-off (spring) and in the middle of the growth season (summer). We aimed to understand the distribution of Arctic epilithic diatoms in relation to water chemistry gradients during the two seasons, to investigate their incorporation into lake sediments and to assess their applicability as palaeoenvironmental indicators. Diatoms were correlated with nutrients in the spring and alkalinity/major ions in the summer, when nutrients were depleted; approximately half of the variance explained was independent of spatial factors. When categorised by functional attributes, diatom seasonal succession differed among regions with the most obvious changes in inland lakes where summer temperatures are warmer, organic nutrient processing is prevalent and silicate is limiting. These conditions led to small, motile and adnate diatoms being abundant in inland lakes during the summer (Nitzschia spp., Encyonopsis microcephala), as these functional attributes are suited to living within complex mats of non-siliceous microbial biofilms. Seasonal succession in silica-rich lakes at the coast was less pronounced and assemblages included Tabellaria flocculosa (indicating more acidic conditions) and Hannaea arcus (indicating input from inflowing rivers). The nitrogen-fixing diatom Epithemia sorex increased from the coast to the ice sheet, negatively correlating with a gradient of reactive nitrogen. The presence of this diatom in Holocene sediment records alongside cyanobacterial carotenoids during arid periods of low nitrogen delivery, suggests that it is a useful indicator of nitrogen limitation. Nitzschia species appear to be associated with high concentrations of organic carbon and heterotrophy, but their poor representation in West Greenland lake sediments due to taphonomic processes limits their palaeoenvironmental application in this region. Proportions of epilithic taxa in lake sediment records of coastal lakes increased during some wetter periods of the Holocene, suggesting that snowpack-derived nutrient delivery may offer diatom taxa living at lake margins a competitive advantage over planktonic diatoms during the “moating” ice melt period. Thus, further research investigating linkages between epilithic diatoms, snowpack and nutrient delivery in seasonally frozen lakes is recommended as these taxa live on the ‘front-line’ during the spring and may be especially sensitive to changes in snowmelt conditions.  相似文献   

Present and historical climate variability in South West England     

A. Kosanic  S. Harrison  K. Anderson  I. Kavcic 《Climatic change》2014,124(1-2):221-237

West Cornwall is the most south westerly part of mainland United Kingdom with a strong maritime climate. This paper analyses the earliest archived instrumental meteorological records collected in West Cornwall (SW England). Observations were obtained from the Met Office archive (Camborne 1957–2010; Culdrose 1985–2011), Trengwainton Garden (1940–2010), and from the Royal Cornwall Polytechnic Society, (data for Falmouth (1880–1952) and Helston (1843–1888)). Homogeneity tests were used (Levene and Brown-Forsythe tests) to exclude any trends not related to climate variability. The data exhibit trends in annual mean and maximum temperatures over the timescales analysed, and show a general temperature increase in the 20th and 21st century. Annual and seasonal temperature change was found to vary locally with strongly positive trends in autumn, spring and summer seasons. Trends in precipitation are positive only for the 19th century and only for one station. Correlation with the North Atlantic Oscillation (NAO) index gives negative results for precipitation data. However correlation with the NAO index is positive with temperature, especially in the winter season. Return period analysis shows a decrease in intensity and frequency of extreme precipitation events in the post-1975 period (Camborne and Trengwainton Garden stations). Climate change in the 20th century and future continued warming is likely to have major implications on biodiversity in this region.  相似文献   

Estimating the propagation velocity of atmospheric fronts from surface wind observations     

Carl Anderson 《大气与海洋》2013,51(3):330-344

Abstract

Surface mesonet winds recorded at 10‐min intervals are used to estimate the propagation velocities of atmospheric fronts in East Coast winter storms during the Canadian Atlantic Storms Program (CASP). The frontal motion is modelled locally as the translation of a line across which there is an abrupt shift in wind direction. The mesonet is used to detect the propagation velocity of the windshift line.

Frontal velocities estimated using mesonet winds for all cases in which fronts passed through the mesonet (two cold fronts and three warm fronts) are in close agreement with those deduced from synoptic charts. Recommendations are given for using the method as a research tool to estimate frontal motions in oceanographic studies of wind‐driven circulation.  相似文献   

A Regional Survey of the Extent and Magnitude of Eutrophication in Mediterranean Estuaries of Southern California,USA     

K. McLaughlin  M. Sutula  L. Busse  S. Anderson  J. Crooks  R. Dagit  D. Gibson  K. Johnston  L. Stratton 《Estuaries and Coasts》2014,37(2):259-278

The magnitude and extent of eutrophication was assessed at 27 segments in 23 estuaries in the Southern California Bight (SCB) between October 2008 and 2009. We applied thresholds from the existing assessment frameworks from both the European Union and the U.S. National Eutrophication Assessment to measurements of three indicators [macroalgae biomass and cover, phytoplankton biomass, and dissolved oxygen (DO) concentration] to categorize eutrophic condition in each estuary. Based on these frameworks, a large fraction of segments had moderate or worse eutrophic condition—78 % based on macroalgae, 39 % for phytoplankton, and 63 % for DO. Macroalgal biomass exceeding 70 g dw m^?2 and 25 % cover was found at 52 % of sites during any sampling event and in 33 % of segments for 8 weeks or longer, a duration found to negatively impact benthic infauna. Duration of hypoxic events (DO?<?4 mg L^?1) was typically short, with most events less than one day; although 53 % of segments had at least one event longer than 24 h. Assessment frameworks of eutrophic condition are likely to evolve over time as the body of literature on eutrophication grows, including aspects such as the applicability of indicators in specific habitat types, indicator thresholds, and how event frequency and duration are incorporated. This paper informs this debate by discussing how eutrophic conditions in SCB estuaries are categorized using different indicators and thresholds. To this end, categorization of estuarine eutrophic condition was found to be very sensitive to the type of threshold, how data are integrated to represent duration or spatial extent, and how indicators are used as multiple lines of evidence.  相似文献   

Mapping subvertical discontinuities in rock cuts using a 400-MHz ground penetrating radar antenna     

Adnan Aqeel  Neil Anderson  Norbert Maerz 《Arabian Journal of Geosciences》2014,7(5):2093-2105

Hidden subvertical discontinuities oriented parallel to subparallel to the exposed faces of outcropping sandstone were effectively mapped at three different study sites in central Missouri using a ground-penetrating radar system (GPR) equipped with a 400-MHz monostatic antenna and a survey wheel. At each site, a suite of 2-D ground-penetrating radar profiles were acquired along multiple closely spaced traverses on relatively smooth exposed rock surfaces. Time-zero correction was applied to the raw GPR data which were then processed using band-pass filtering, range and display gain, color transformation, and deconvolution techniques. Pseudo 3D images of each identified discontinuity at each site were constructed based on the interpretation of the nonmigrated ground-penetrating radar profiles. These pseudo 3D images were hand-migrated and transformed into true 3D images which depict variable depths at “perpendicular horizontal distance” to each discontinuity relative to the exposed rock face. The results demonstrate that GPR can be used to detect and map hidden discontinuities. This information can then be used for rock slope stability analysis and rock engineering purposes.  相似文献   

An assessment of aquifer storage recovery using ground water flow models   总被引：3，自引：0，他引：3  

Lowry CS  Anderson MP 《Ground water》2006,44(5):661-667

Owing to increased demands on ground water accompanied by increased drawdowns, technologies that use recharge options, such as aquifer storage recovery (ASR), are being used to optimize available water resources and reduce adverse effects of pumping. In this paper, three representative ground water flow models were created to assess the impact of hydrogeologic and operational parameters/factors on recovery efficiency of ASR systems. Flow/particle tracking and solute transport models were used to track the movement of water during injection, storage, and recovery. Results from particle tracking models consistently produced higher recovery efficiency than the solute transport models for the parameters/properties examined because the particle tracking models neglected mixing of the injected and ambient water. Mixing between injected and ambient water affected recovery efficiency. Results from this study demonstrate the interactions between hydrogeologic and operational parameters on predictions of recovery efficiency. These interactions are best simulated using coupled numerical ground water flow and transport models that include the effects of mixing of injected water and ambient ground water.  相似文献   

Plagiarism, copyright violation, and dual publication: are you guilty?     

Anderson MP 《Ground water》2006,44(5):623-623

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Glacimarine environments: Processes and sediments,Edited by J. A. Dowdeswell and J. D. Scourse,Geological Society Special Publication 53, London 1990. No. of pages: 423. Price: £75.00 ($125.00) (hardback)     

John B. Anderson 《Geological Journal》1991,26(4):352-352

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The Golden meteorite fall: Fireball trajectory,orbit, and meteorite characterization     

P. G. Brown  P. J. A. McCausland  A. R. Hildebrand  L. T. J. Hanton  L. M. Eckart  H. Busemann  D. Krietsch  C. Maden  K. Welten  M. W. Caffee  M. Laubenstein  D. Vida  F. Ciceri  E. Silber  C. D. K. Herd  P. Hill  H. Devillepoix  Eleanor K. Sansom  Martin Cupák  Seamus Anderson  R. L. Flemming  A. J. Nelson  M. Mazur  D. E. Moser  W. J. Cooke  D. Hladiuk  Barbara Malečić  Maja Telišman Prtenjak  R. Nowell  The Golden Meteorite Consortium 《Meteoritics & planetary science》2023,58(12):1773-1807

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