The geological results of measurements of gravity in East Carmarthenshire     

Professor J. T. Whetton D.S.O.  O.B.E.  M.C.  T.D.  M.Sc.  J. O. Myers B.Sc.  A.M.I.Min.E.  I. J. Watson B.Sc.  Ph.D. 《Pure and Applied Geophysics》1955,32(1):43-53

Summary Observations of gravity over the Palaeozoic rocks of East Carmarthenshire show this to be an area of positive Bouguer anomalies, and throughout the district the isogams are aligned in a «Caledonoid» direction. The regional gradient over the anthracite coalfield can largely be explained in terms of known structure, while the anomaly values in the Towy valley above Llandeilo seem to have been affected by facies variations and contemporaneous volcanic activity. Fairly large anomalies are recorded near Carmarthen, and these may be associated with similar anomalies known near Aberystwyth (Cook & Thirlaway, 1950); they are interpreted as an expression of the Welsh geosyncline. The gravity low discovered in St. George's Channel byBrowne & Cooper (1950) is re-interpreted in terms of the depth of the pre-Palaeozoic floor. There is no marked evidence to indicate the presence of a concealed «granitic» intrusion beneath the coalfield, nor to substantiate the view that there was once a great thickness of Permian or later cover.  相似文献   

Coals of the Brazil Formation (Pennsylvanian) in Indiana: observations of correlation inconsistencies and their implications     

Maria Mastalerz  Philip R. Ames  Penny L. Padgett   《International Journal of Coal Geology》2003,54(3-4):209

The coals of the upper part of the Mansfield, Brazil, and the lower part of the Staunton Formations (Atokan and Desmoinesian, Pennsylvanian) in Indiana (Illinois Basin) are characteristically thin and discontinuous. As a result, problems with correlation and identification of the seams have persisted for both researchers and industry. These discrepancies affect coal exploration, mine planning, and subsequently coal-fired utilities. This study presents exploration and operational examples demonstrating some of the correlation problems associated with the coals of the Brazil Formation, and the Upper Block and Lower Block, in particular, and the surrounding upper part of the Mansfield Formation and lower part of the Staunton Formations. Based on exploration boreholes, mine scale observations, and coal quality and petrographic data, this study suggests that (1) the coal mapped as the Upper Block Coal Member of Clay County may, in fact, be the same seam as the Lower Block Coal Member of Daviess County; and (2) the Lower Block coal of Clay County is not present south of the Switz City area of central Greene County, IN.  相似文献   

Trends in nutrients     

A. Louise Heathwaite  Penny J. Johnes  Norman E. Peters 《水文研究》1996,10(2):263-293

The roles of nitrogen (N) and phosphorus (P) as key nutrients determining the trophic status of water bodies are examined, and evidence reviewed for trends in concentrations of N and P species which occur in freshwaters, primarily in northern temperate environments. Data are reported for water bodies undergoing eutrophication and acidification, especially water bodies receiving increased nitrogen inputs through the atmospheric deposition of nitrogen oxides (NO_x). Nutrient loading on groundwaters and surface freshwaters is assessed with respect to causes and rates of change, relative rates of change for N and P, and implications of change for the future management of lakes, rivers and groundwaters. In particular, the nature and emphasis of studies for N species and P fractions in lakes versus rivers and groundwaters are contrasted. This review paper primarily focuses on results from North America and Europe, particularly for the UK where a wide range of data sets exists. Few nutrient loading data have been published on water bodies in less developed countries; however, some of the available data are presented to provide a global perspective. In general, N and P concentrations have increased dramatically (>20 times background concentrations) in many areas and causes vary considerably, ranging from urbanization to changes in agricultural practices.  相似文献   

The metal homogeneity of the globular star cluster M5     

A. J. Heald  W. K. Griffiths  A. J. Penny  P. W. Morris 《Monthly notices of the Royal Astronomical Society》1999,307(4):789-801

This work is concerned with the precision measurement of the magnitudes of the stars across a large field of the galactic globular cluster M5. The colours of the red giants are subjected to a thorough statistical analysis in order to quantify the extent of any star-to-star variations in metal abundance within the cluster. Use is made of an extensive optical/near-infrared observational data set acquired with a large-array CCD detector and the Johnson V and I filters. The results of this photometry, which is accurate to within a few millimagnitudes for the brighter stars, are used to compile a colour–magnitude diagram.
The analysis finds that in a metal-rich M5 ([Fe/H]=−1.2) the extent of any metal inhomogeneity, Δ[Fe/H], is less than ±0.1 dex, and in a metal-poor M5 ([Fe/H]=−1.5) then     . (The literature contains a range of derived values of metallicity for M5.)  相似文献   

Joint traveltime inversion of wide-angle seismic data and a deep reflection profile from the central North Sea     

Michael McCaughey  Penny Barton  & Satish Singh 《Geophysical Journal International》2000,141(1):100-114

We report results from the Seismic Wide-Angle and Broadband Survey carried out over the Mid North Sea High. This paper focuses on integrating the information from a conventional deep multichannel reflection profile and a coincident wide-angle profile obtained by recording the same shots on a set of ocean bottom hydrophones (OBH). To achieve this integration, a new traveltime inversion scheme was developed (reported elsewhere) that was used to invert traveltime information from both the wide-angle OBH records and the reflection profile simultaneously. Results from the inversion were evaluated by producing synthetic seismograms from the final inversion model and comparing them with the observed wide-angle data, and an excellent match was obtained. It was possible to fine-tune velocities in less well-resolved parts of the model by considering the critical distance for the Moho reflection. The seismic velocity model was checked for compatibility with the gravity field, and used to migrate and depth-convert the reflection profile. The unreflective upper crust is characterized by a high velocity gradient, whilst the highly reflective lower crust is associated with a low velocity gradient. At the base of the crust there are several subhorizontal reflectors, a few kilometres apart in depth, and correlatable laterally for several tens of kilometres. These reflectors are interpreted as representing a strike section through northward-dipping reflectors at the base of the crust, identified on orthogonal profiles by Freeman et al. (1988) as being slivers of subducted and imbricated oceanic crust, relics of the mid-Palaeozoic Iapetus Ocean.  相似文献   

North Atlantic extratropical and subpolar gyre variability during the last 120 years: a gridded dataset of surface temperature,salinity, and density. Part 1: dataset validation and RMS variability     

Reverdin  Gilles  Friedman  Andrew Ronald  Chafik  Léon  Holliday  Naomi Penny  Szekely  Tanguy  Valdimarsson  Héðinn  Yashayaev  Igor 《Ocean Dynamics》2019,69(3):385-403

We present a binned annual product (BINS) of sea surface temperature (SST), sea surface salinity (SSS), and sea surface density (SSD) observations for 1896–2015 of the subpolar North Atlantic between 40° N and 70° N, mostly excluding the shelf areas. The product of bin averages over spatial scales on the order of 200 to 500 km, reproducing most of the interannual variability in different time series covering at least the last three decades or of the along-track ship monitoring. Comparisons with other SSS and SST gridded products available since 1950 suggest that BINS captures the large decadal to multidecadal variability. Comparison with the HadSST3 SST product since 1896 also indicates that the decadal and multidecadal variability is usually well-reproduced, with small differences in long-term trends or in areas with marginal data coverage in either of the two products. Outside of the Labrador Sea and Greenland margins, interannual variability is rather similar in different seasons. Variability at periods longer than 15 years is a large part of the total interannual variability, both for SST and SSS, except possibly in the south-western part of the domain. Variability in SST and SSS increases towards the west, with the contribution of salinity variability to density dominating that of temperature in the western Atlantic, except close to the Gulf Stream and North Atlantic Current in the southwest area. Weaker variability and larger relative temperature contributions to density changes are found in the eastern part of the gyre and south of Iceland.

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A search for starlight reflected from HD 75289b     

Christopher Leigh  rew Collier Cameron  Stephane Udry  Jean-François Donati  Keith Horne  David James  Alan Penny 《Monthly notices of the Royal Astronomical Society》2003,346(2):L16-L20

We have used a Doppler tomographic analysis to conduct a deep search for the starlight reflected from the planetary companion to HD 75289. In four nights on VLT(UT2)/UVES in 2003 January, we obtained 684 high-resolution echelle spectra with a total integration time of 26 h. We establish an upper limit on the geometric albedo of the planet   p < 0.12  (to the 99.9 per cent significance level) at the most probable orbital inclination   i ≃ 60°  , assuming a grey albedo, a Venus-like phase function and a planetary radius   R _p= 1.6 R_Jup  . We are able to rule out some combinations of the predicted planetary radius and atmospheric albedo models with high, reflective cloud decks.  相似文献   

High-eccentricity planets from the Anglo-Australian Planet Search     

Hugh R. A. Jones  R. Paul Butler  C. G. Tinney  Geoffrey W. Marcy  Brad D. Carter  Alan J. Penny  Chris McCarthy  Jeremy Bailey 《Monthly notices of the Royal Astronomical Society》2006,369(1):249-256

We report Doppler measurements of the stars HD 187085 and HD 20782 which indicate two high eccentricity low-mass companions to the stars. We find HD 187085 has a Jupiter-mass companion with a ∼1000-d orbit. Our formal 'best-fitting' solution suggests an eccentricity of 0.47, however, it does not sample the periastron passage of the companion and we find that orbital solutions with eccentricities between 0.1 and 0.8 give only slightly poorer fits (based on rms and  χ²_ν  ) and are thus plausible. Observations made during periastron passage in 2007 June should allow for the reliable determination of the orbital eccentricity for the companion to HD 187085. Our data set for HD 20782 does sample periastron and so the orbit for its companion can be more reliably determined. We find the companion to HD 20782 has   M sin   i = 1.77 ± 0.22  M _Jup  , an orbital period of 595.86 ± 0.03 d and an orbit with an eccentricity of 0.92 ± 0.03. The detection of such high-eccentricity (and relatively low-velocity amplitude) exoplanets appears to be facilitated by the long-term precision of the Anglo-Australian Planet Search. Looking at exoplanet detections as a whole, we find that those with higher eccentricity seem to have relatively higher velocity amplitudes indicating higher mass planets and/or an observational bias against the detection of high-eccentricity systems.  相似文献   

The Origins and Consequences of democratic citizens' Policy Agendas: A Study of Popular Concern about Global Warming     

Jon A. Krosnick  Allyson L. Holbrook  Laura Lowe  Penny S. Visser 《Climatic change》2006,77(1-2):7-43

This article proposes and tests a model of the causes and consequences of Americans’ judgments of the national seriousness of global warming. The model proposes that seriousness judgments about global warming are a function of beliefs about the existence of global warming, attitudes toward it, the certainty with which these beliefs and attitudes are held, and beliefs about human responsibility for causing global warming and people’s ability to remedy it. The model also proposes that beliefs about whether global warming is a problem are a function of relevant personal experiences (with the weather) and messages from informants (in this case, scientists), that attitudes toward global warming are a function of particular perceived consequences of global warming, and that certainty about these attitudes and beliefs is a function of knowledge and prior thought. Data from two representative sample surveys offer support for all of these propositions, document effects of national seriousness judgments on support for ameliorative efforts generally and specific ameliorative policies, and thereby point to psychological mechanisms that may be responsible for institutional and elite impact on the public’s assessments of national problem importance and on public policy preferences.  相似文献   

Adaptive traveltime tomography of densely sampled seismic data   总被引：1，自引：0，他引：1  

Immo Trinks  Satish C. Singh  Chris H. Chapman  Penny J. Barton  Miguel Bosch  Adam Cherrett 《Geophysical Journal International》2005,160(3):925-938

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