The stratigraphy and structure of the Port Isaac Area,North Cornwall     

D.M. Hobson 《Proceedings of the Geologists' Association. Geologists' Association》1974,85(4):473-491

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The Ethics of Waste: How we relate to rubbish - by Gay Hawkins     

Kersty  Hobson 《The Geographical journal》2007,173(1):95-96

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SPECTROSCOPY OF A GEMINID FIREBALL: ITS SIMILARITY TO COMETARY METEOROIDS AND THE NATURE OF ITS PARENT BODY     

J. M. TRIGO-RODRíGUEZ  J. LLORCA  J. BOROVIČKA  J. FABREGAT 《Earth, Moon, and Planets》2004,95(1-4):375-387

A detailed analysis of a photographic spectrum of a Geminid fireball obtained in December 14, 1961 at the Ondrejov Observatory is presented. We have computed a synthetic spectrum for the fireball and compared it with the observed spectrum assuming chemical equilibrium in the meteor head. In this way we have determined relative chemical abundances in meteor vapors. Comparing the relative chemical abundances of this Geminid meteoroid with those obtained from meteoroids associated with comets 55P/Tempel-Tuttle and 109P/Swift-Tuttle we found no significant chemical differences in main rock-forming elements. Despite of this similarity, the deepest penetration of the Geminid meteoroids and their ability to reach high rotation rates in space without fragmentation suggest that thermal processing is affecting their physical properties. We suggest that as consequence of space weathering a high-strength envelope is produced around these particles. In this picture, heating processes of the mineral phases could result in the peculiar properties observed during atmospheric entry of the Geminid meteoroids, especially their strength, which is evidenced by its resistance to ablation. Finally, although one meteoroid cannot be obviously considered as representative of the composition of its parent body, we conclude that 3200 Phaethon is able to produce millimetre-size debris nearly chondritic in composition, but the measured slight overabundance of Na would support a cometary origin for this body.  相似文献   

Maximum-entropy weak lens reconstruction: improved methods and application to data     

P. J. Marshall  M. P. Hobson  S. F. Gull  S. L. Bridle 《Monthly notices of the Royal Astronomical Society》2002,335(4):1037-1048

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A maximum-entropy method for reconstructing the projected mass distribution of gravitational lenses     

S. L. Bridle  M. P. Hobson  A. N. Lasenby  & Richard Saunders 《Monthly notices of the Royal Astronomical Society》1998,299(3):895-903

The maximum-entropy method is applied to the problem of reconstructing the projected mass density of a galaxy cluster using its gravitational lensing effects on background galaxies. We demonstrate the method by reconstructing the mass distribution in a model cluster using simulated shear and magnification data to which Gaussian noise is added. The mass distribution is reconstructed directly and the inversion is regularized using the entropic prior for this positive additive distribution. For realistic noise levels, we find that the method faithfully reproduces the main features of the cluster mass distribution not only within the observed field but also slightly beyond it. We estimate the uncertainties in the reconstruction by calculating an analytic approximation to the covariance matrix of the reconstruction values of each pixel. This result is compared with error estimates derived from Monte Carlo simulations for different noise realizations and found to be in good agreement.  相似文献   

A graphical solution of the problem of two tilts     

G.D. Hobson 《Proceedings of the Geologists' Association. Geologists' Association》1943,54(1):29-32

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Climate stability during the Eemian – new pollen evidence from the Nidzica site,northern Poland     

KRZYSZTOF BIŃKA  JERZY NITYCHORUK  JAN DZIERŻEK 《Boreas: An International Journal of Quaternary Research》2011,40(2):342-350

Bińka, K., Nitychoruk, J. & Dzier?ek, J. 2010: Climate stability during the Eemian – new pollen evidence from the Nidzica site, northern Poland. Boreas, 10.1111/j.1502‐3885.2010.00179.x. ISSN 0300‐9483 Interglacial sediments at Nidzica, northern Poland were investigated by means of pollen and isotope analysis. These deposits accumulated in an extensive basin through most of the Eemian and Early Weichselian, practically without stratigraphic gaps. Continuous subsidence of the basin floor has resulted in the accumulation of a great thickness of lacustrine sediments, consisting mostly of calcareous gyttja. The course of pollen and isotope curves in the interglacial interval does not indicate the abrupt climatic shifts reported from some other continental climatic archives. Particularly important has been the reconstruction of the final stages of the Eemian, a potential analogue for future climatic change in the late Holocene. At Nidzica, this period is registered as a gradual modification of forest composition, devoid of any pulsations in which temperate forest is followed by terminal, boreal pine–birch communities.  相似文献   

A high-significance detection of non-Gaussianity in the Wilkinson Microwave Anisotropy Probe 1-yr data using directional spherical wavelets     

J. D. McEwen  M. P. Hobson  A. N. Lasenby  D. J. Mortlock 《Monthly notices of the Royal Astronomical Society》2005,359(4):1583-1596

A directional spherical wavelet analysis is performed to examine the Gaussianity of the Wilkinson Microwave Anisotropy Probe ( WMAP ) 1-yr data. Such an analysis is facilitated by the introduction of a fast directional continuous spherical wavelet transform. The directional nature of the analysis allows us to probe orientated structure in the data. Significant deviations from Gaussianity are detected in the skewness and kurtosis of spherical elliptical Mexican hat and real Morlet wavelet coefficients for both the WMAP and Tegmark, de Oliveira-Costa & Hamilton foreground-removed maps. The previous non-Gaussianity detection made by Vielva et al. using the spherical symmetric Mexican hat wavelet is confirmed, although their detection at the 99.9 per cent significance level is only made at the 95.3 per cent significance level using our most conservative statistical test. Furthermore, deviations from Gaussianity in the skewness of spherical real Morlet wavelet coefficients on a wavelet scale of 550 arcmin (corresponding to an effective global size on the sky of ∼26° and an internal size of ∼3°) at an azimuthal orientation of 72°, are made at the 98.3 per cent significance level, using the same conservative method. The wavelet analysis inherently allows us to localize on the sky those regions that introduce skewness and those that introduce kurtosis. Preliminary noise analysis indicates that these detected deviation regions are not atypical and have average noise dispersion. Further analysis is required to ascertain whether these detected regions correspond to secondary or instrumental effects, or whether in fact the non-Gaussianity detected is due to intrinsic primordial fluctuations in the cosmic microwave background.  相似文献   

A Potential Flood Hazard Caused by Tianchi Volcano Eruption in Changbai Mountain, Northeast China     

Neil B. McLaughlin 《山地科学学报》2011,(5)

Geohazards appear to be increasing in frequency globally. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented by the huge volume of water in Tianchi Lake, the unique geography of Changbai Mountain, and the limited flood control ability in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changbai volcano cooperatively,...  相似文献   

Detection of the integrated Sachs–Wolfe effect and corresponding dark energy constraints made with directional spherical wavelets     

J. D. McEwen  P. Vielva  M. P. Hobson  E. Martínez-González  A. N. Lasenby 《Monthly notices of the Royal Astronomical Society》2007,376(3):1211-1226

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