Geology and the Allied liberation of Normandy: highlights to help mark the 75th anniversary of D‐Day, 6 June 1944     

Edward P. F. Rose 《Geology Today》2019,35(3):107-114

During the Second World War, the Allied invasion of the French coast of Normandy on D‐Day, 6 June 1944, was the greatest amphibious assault in world history. An article in Geology Today (v.11, for 1995, pp.58–63) marked the 50th anniversary of the end of the war in Europe, on 8 May 1945, by describing how British military geologists had participated in planning for D‐Day and in the NW Europe campaign that followed it. The work of these geologists provides a classic case history, revealing that ‘military geology’ has many potential applications. Geological factors influenced site selection for temporary airfields, predictions of trafficability for the Normandy beaches, the development of potable water supplies, and quarrying for road metal—and more besides. This new article helps to mark the 75th anniversary of D‐Day by further details of how geologists and geology contributed to Allied victory.  相似文献   

Investigating the mechanisms leading to the deglaciation of past continental northern hemisphere ice sheets with the CLIMBER–GREMLINS coupled model     

Sylvie Charbit  Masa Kageyama  Didier Roche  Catherine Ritz  Gilles Ramstein 《Global and Planetary Change》2005,48(4):1887

A coupling procedure between a climate model of intermediate complexity (CLIMBER-2.3) and a 3-dimensional thermo-mechanical ice-sheet model (GREMLINS) has been elaborated. The resulting coupled model describes the evolution of atmosphere, ocean, biosphere, cryosphere and their mutual interactions. It is used to perform several simulations of the Last Deglaciation period to identify the physical mechanisms at the origin of the deglaciation process. Our baseline experiment, forced by insolation and atmospheric CO₂, produces almost complete deglaciation of past northern hemisphere continental ice sheets, although ice remains over the Cordilleran region at the end of the simulation and also in Alaska and Eastern Siberia. Results clearly demonstrate that, in this study, the melting of the North American ice sheet is critically dependent on the deglaciation of Fennoscandia through processes involving switches of the thermohaline circulation from a glacial mode to a modern one and associated warming of the northern hemisphere. A set of sensitivity experiments has been carried out to test the relative importance of both forcing factors and internal processes in the deglaciation mechanism. It appears that the deglaciation is primarily driven by insolation. However, the atmospheric CO₂ modulates the timing of the melting of the Fennoscandian ice sheet, and results relative to Laurentide illustrate the existence of threshold CO₂ values, that can be translated in terms of critical temperature, below which the deglaciation is impeded. Finally, we show that the beginning of the deglaciation process of the Laurentide ice sheet may be influenced by the time at which the shift of the thermohaline circulation from one mode to the other occurs.  相似文献   

Radar observations of Itokawa in 2004 and improved shape estimation     

Steven J. Ostro  Lance A. M. Benner  Christopher Magri  Jon D. Giorgini  Randy Rose  Raymond F. Jurgens  Donald K. Yeomans  Alice A. Hine  Michael C. Nolan  Daniel J. Scheeres  Stephen B. Broschart  Mikko Kaasalainen  Jean‐Luc Margot 《Meteoritics & planetary science》2005,40(11):1563-1574

Abstract— We present June 2004 radar images of asteroid 25143 Itokawa (1998 SF36) that improve upon the longitude‐latitude coverage of images obtained in 2001 by Ostro et al. (2004) and use the 2001–2004 data to refine that paper's constraints on Itokawa's shape. The 2004 images, the first of the asteroid's southern side, look distinctly different from the 2001 images, revealing leading edges that are much more curved and rugged than the nearly convex leading edges seen at northern latitudes in 2001. Itokawa is shaped like a slightly asymmetrical, bent, lumpy ellipsoid with dimensions along the principal axes within 10% of 594 times 320 times 288 m. To illustrate the uncertainty space associated with shape reconstruction from images with suboptimal orientational coverage, we present two alternative three‐dimensional models of the object.  相似文献   

Weak lensing with COMBO-17: estimation and removal of intrinsic alignments     

Catherine Heymans  Michael Brown  Alan Heavens  Klaus Meisenheimer  y Taylor  Christian Wolf 《Monthly notices of the Royal Astronomical Society》2004,347(3):895-908

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Modeling X-Ray Photoionized Plasmas Produced at the Sandia Z-Facility     

P. A. M. Van Hoof  M. E. Foord  R. F. Heeter  J. E. Bailey  H.-K. Chung  M. E. Cuneo  W. H. Goldstein  V. Jonauskas  F. P. Keenan  R. Kisielius  D. A. Liedahl  C. Ramsbottom  S. J. Rose  P. T. Springer  R. S. Thoe 《Astrophysics and Space Science》2005,298(1-2):147-153

In experiments at the high-power Z-facility at Sandia National Laboratory in Albuquerque, New Mexico, we have been able to produce a low density photoionized laboratory plasma of Fe mixed with NaF. The conditions in the experiment allow a meaningful comparison with X-ray emission from astrophysical sources. The charge state distributions of Fe, Na and F are determined in this plasma using high resolution X-ray spectroscopy. Independent measurements of the density and radiation flux indicate unprecedented values for the ionization parameter ξ = 20–25 erg cm s⁻¹ under nearly steady-state conditions. First comparisons of the measured charge state distributions with X-ray photoionization models show reasonable agreement, although many questions remain.  相似文献   

Deconvolution of long-core palaeomagnetic measurements—spline therapy for the linear problem     

Catherine Constable  Robert Parker 《Geophysical Journal International》1991,104(3):453-468

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Static compression of α-MnS at 298 K to 21 GPa     

Catherine McCammon 《Physics and Chemistry of Minerals》1991,17(7):636-641

To investigate the equation of state of -MnS at high pressure and the possibility of a phase transition, the compression curve was measured at 298 K from 0 to 21 GPa using powder x-ray diffraction with a diamond anvil cell. The compression data are fit to a thirdorder Birch-Murnaghan equation of state, with parameters K ₀ = 72(2) GPa and K ₀ = 4.2(13). To compare present results with previous work, the data sets from three previous investigations (Clendenen and Drickamer 1966; Wakabayashi et al. 1968; Kraft and Greuling 1988) are refit to a Birch-Murnaghan equation of state. In the low pressure region (P < 10=" gpa),=" the=" results=" of=" clendenen=" and=" drickamer=" (1966)=" agree=" with=" the=" present=" data;=" however=" the=" results=" of=" wakbayashi=" et=" al.=" (1968)=" differ=" by=" more=" than=" 10%.=" a=" greater=" discrepancy=" between=" the=" present=" and=" previous=" results=" occurs=" above=" 10=" gpa.=" kraft=" and=" greuling=" (1988)=" reported=" a=" structure=" transition=" at=" 7=" gpa,=" and=" clendenen=" and=" drickamer=" (1966)=" observed=" a=" structure=" distortion=" at=" approximately=" 10=" gpa;=" the=" present=" data=" show=" no=" evidence=" of=" either=" transition,=" and=" are=" well=" fit=" by=" a=" single=" equation=" of=" state=" from=" 0=" to=" 21=" gpa.=" nonhydrostatic=" stress=" is=" discussed=" as=" one=" possibility=" for=" the=">  相似文献   

Growing up green on serpentine soils: Biogeochemistry of serpentine vegetation in the Central Coast Range of California     

Christopher Oze  Catherine Skinner  Andrew W. Schroth  Robert G. Coleman 《Applied Geochemistry》2008,23(12):3391-3403

Serpentine soils derived from the weathering of ultramafic rocks and their metamorphic derivatives (serpentinites) are chemically prohibitive for vegetative growth. Evaluating how serpentine vegetation is able to persist under these chemical conditions is difficult to ascertain due to the numerous factors (climate, relief, time, water availability, etc.) controlling and affecting plant growth. Here, the uptake, incorporation, and distribution of a wide variety of elements into the biomass of serpentine vegetation has been investigated relative to vegetation growing on an adjacent chert-derived soil. Soil pH, electrical conductivity, organic C, total N, soil extractable elements, total soil elemental compositions and plant digestions in conjunction with spider diagrams are utilized to determine the chemical relationships of these soil and plant systems. Plant available Mg and Ca in serpentine soils exceed values assessed in chert soils. Magnesium is nearly 3 times more abundant than Ca in the serpentine soils; however, the serpentine soils are not Ca deficient with Ca concentrations as high as 2235 mg kg⁻¹. Calcium to Mg ratios (Ca:Mg) in both serpentine and chert vegetation are greater than one in both below and above ground tissues. Soil and plant chemistry analyses support that Ca is not a limiting factor for plant growth and that serpentine vegetation is actively moderating Mg uptake as well as tolerating elevated concentrations of bioavailable Mg. Additionally, results demonstrate that serpentine vegetation suppresses the uptake of Fe, Cr, Ni, Mn and Co into its biomass. The suppressed uptake of these metals mainly occurs in the plants’ roots as evident by the comparatively lower metal concentrations present in above ground tissues (twigs, leaves and shoots). This research supports earlier studies that have suggested that ion uptake discrimination and ion suppression in the roots are major mechanisms for serpentine vegetation to tolerate the chemistry of serpentine soils.  相似文献   

Evaluation of the Shepherd and Cushing (1980) model of density-dependent survival: a case study using striped bass (Morone saxatilis) larvae in the Potomac River, Maryland, USA     

Rutherford  Edward S; Rose  Kenneth A; Cowan  James H  Jr. 《ICES Journal of Marine Science》2003,60(6):1275-1287

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Metabolism of perylene by monooxygenases of the skin and liver of Ambystoma tigrinum     

Robert S Anderson  Marilyn A Angel  Francis L Rose 《Marine environmental research》1988,24(1-4)

The prevalence of dermal neoplasia among neotenic tiger salamanders (Ambystoma tigrinum) collected from the Reese Air Force Base sewage lagoon far exceeded that among salamanders from nearby uncontaminated lagoons. Perylene was the predominant pglycyclic aromatic hydrocarbon contaminant in this lagoon. Perylene was shown to be a substrate for monooxygenases in skin and liver homogenates and formed DNA-binding metabolites. Perylene exposure appeared to augment subsequent perylene metabolism by dermal enzymes but it was not a strong inducer of hepatic monooxygenases. Aroclor 1254 induced benzo(a)pyrene and perylene metabolism by both skin and liver enzymes. However, perylene apparently was not activated by salamander enzymes, as suggested by its lack of in vitro mutagenicity and failure to induce tumors.  相似文献