bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural change around a needle probe to measure thermal conductivity of snow
Authors: Riche Fabienne , Schneebeli Martin 
Published: January 2011

AbstractThe thermal conductivity of snow determines, to a large extent, ground heat flux and snow metamorphism. One common method of measuring the thermal conductivity of snow is with a needle probe. We measured the microstructural changes in the snow around a typical needle using micro- computed tomography. The insertion of the needle probe caused structural changes up to a radial distance of 0.5-1 mm. Using a commercial needle probe with short (30 s) heating time, we measured thermal conductivity values in snow that were 50% lower than the conductivity measured using a calibrated guarded hot-plate apparatus. Numerically simulated time-temperature curves with an introduced air gap that simulated the needle damage reproduced the observed needle-probe results well, confirming that poor contact resistance between the needle and the snow will lead to measurement discrepancies and a large bias. While most measurements in snow have been done using a long heating time and are not subject to this error, the thermal conductivity of snow measured with needle probes with short measurement times should be avoided. This same effect is probably observed in other brittle and highly porous materials, a condition that may not be widely appreciated.
A unifying framework for iceberg-calving models
Authors: Amundson Jason M. , Truffer Martin 
Published: January 2011

AbstractWe propose a general framework for iceberg-calving models that can be applied to any calving margin. The framework is based on mass continuity, the assumption that calving rate and terminus velocity are not independent and the simple idea that terminus thickness following a calving event is larger than terminus thickness at the event onset. The theoretical, near steady-state analysis used to support and analyze the framework indicates that calving rate is governed, to first order, by ice thickness, thickness gradient, strain rate, mass-balance rate and backwards melting of the terminus; the analysis furthermore provides a physical explanation for a previously derived empirical relationship for ice-shelf calving (Alley and others, 2008). In the calving framework the pre- and post-calving terminus thicknesses are given by two unknown but related functions. The functions can vary independently of changes in glacier flow and geometry, and can therefore account for variations in calving behavior due to external forcings and/or self-sustaining calving processes (positive feedbacks). Although the calving framework does not constitute a complete calving model, any thickness-based calving criterion can easily be incorporated into the framework. The framework should be viewed as a guide for future attempts to parameterize calving.
Discovery of a nanodiamond-rich layer in the Greenland ice sheet
Authors: Kurbatov Andrei V. , Mayewski Paul A. , Steffensen Jorgen P. , West Allen , Kennett Douglas J. , Kennett James P. , Bunch Ted E. , Handley Mike , Introne Douglas S. , Que Hee Shane S. , Mercer Christopher , Sellers Marilee , Shen Feng , Sneed Sharon B. , Weaver James C. , Wittke James H. , Stafford Thomas W. , Donovan John J. , Xie Sujing , Razink Joshua J. , Stich Adrienne , Kinzie Charles R. , Wolbach Wendy S. 
Published: January 2011

AbstractWe report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5×106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 ± 0.1 ka. However, more investigation is needed to confirm this association.
Identification and characterization of alpine subglacial lakes using interferometric synthetic aperture radar (InSAR): Brady Glacier, Alaska, USA
Authors: Capps Denny M. , Rabus Bernhard , Clague John J. , Shugar Daniel H. 
Published: January 2011

AbstractThe temporary storage and subsequent release of water at glacial margins can cause severe flooding in downstream areas and substantially impact glacier dynamics. Alpine subglacial lakes may not be identified until they become subaerially exposed or release a jokulhlaup. We use interferometric synthetic aperture radar (InSAR) to identify and characterize three dynamic alpine subglacial lakes of Brady Glacier, Alaska, USA. We quantify changes in vertical displacement of the glacier surface and lake volumes from September 1995 through March 1996 using European Remote-sensing Satellite-1/-2 (ERS- 1/-2) tandem data. In the autumn, subsidence ranged from 4 to 26cmd-1 and the volume of water discharged ranged from 22 000 ± 2000 to 243 000 ± 14 000m3d-1. Subsidence and discharge rates declined significantly during the winter and continued at a lesser rate through March. Application of this technique may allow researchers to locate alpine subglacial lakes years or decades before they begin to release hazardous outburst floods and substantially impact glacier dynamics.
Strong-wind events and their influence on the formation of snow dunes: observations from Kohnen station, Dronning Maud Land, Antarctica
Authors: Birnbaum Gerit , Freitag Johannes , Brauner Ralf , König-Langlo Gert , Schulz Elisabeth , Kipfstuhl Sepp , Oerter Hans , Reijmer Catharina H. , Schlosser Elisabeth , Faria Sergio H. , Ries Hinnerk , Loose Bernd , Herber Andreas , Duda Michael G. , Powers Jordan G. , Manning Kevin W. , Van Den Broeke Michiel R. 
Published: January 2011

AbstractAnalyses of shallow cores obtained at the European Project for Ice Coring in Antarctica (EPICA) drilling site Kohnen station (75°00′ S, 00°04′ E; 2892 m a.s.l.) on the plateau of Dronning Maud Land reveal the presence of conserved snow dunes in the firn. In situ observations during three dune formation events in the 2005/06 austral summer at Kohnen station show that these periods were characterized by a phase of 2 or 3 days with snowdrift prior to dune formation which only occurred during high wind speeds of >10 m s-1 at 2 m height caused by the influence of a low-pressure system. The dune surface coverage after a formation event varied between 5% and 15%, with a typical dune size of (4 ± 2) m × (8 ± 3) m, a maximum height of 0.2 ± 0.1 m and a periodicity length of about 30 m. The mean density within a snow dune varied between 380 and 500 kg m-3, whereas the mean density at the surrounding surface was 330 ± 5 kgm-3. The firn cores covering a time-span of 22 ± 2 years reveal that approximately three to eight events per year occurred, during which snow dunes had been formed and were preserved in the firn.
On optimal stability-test spacing for assessing snow avalanche conditions
Authors: Birkeland Karl W. , Hendrikx Jordy , Clark Martyn P. 
Published: January 2011

AbstractAssessing snow stability requires a holistic approach, relying on avalanche, snowpack and weather observations. Part of this assessment utilizes stability tests, but these tests can be unreliable due in part to the spatial variability of test results. Conducting more than one test can help to mitigate this uncertainty, though it is unclear how far apart to space tests to optimize our assessments. To address this issue we analyze the probability of sampling two relatively strong test results over 25 spatial datasets collected using a variety of stability tests. Our results show that the optimal distance for spacing stability tests varies by dataset, even when taking the sampling scheme and stability-test type into account. This suggests that no clear rule currently exists for spacing stability tests. Our work further emphasizes the spatial complexity of snow stability measurements, and the need for holistic stability assessments where stability tests are only one part of a multifaceted puzzle.
Using a draw-wire sensor to continuously monitor glacier melt
Authors: Hulth John 
Published: January 2011

AbstractA draw-wire sensor has successfully been used to measure surface lowering due to net ablation of a glacier. A thin steel wire attached to a weight is inserted and frozen into a borehole in the ice. The draw-wire sensor, installed on a tetrahedron on the surface, retracts the wire as the snow or ice melts. Relative surface lowering of the melting surface is recorded in a data logger and may be converted to mass loss. The instrument continuously logs net ablation over several melt seasons and has the potential to be used extensively in future studies of glacier melt, whenever high temporal resolution and precision are required.
Analysis and forecast of extreme new-snow avalanches: a numerical study of the avalanche cycles of February 1999 in France
Authors: Rousselot Marie , Durand Yves , Giraud Gérald , Merindol Laurent , Daniel Luc 
Published: January 2011

AbstractSnow and weather conditions typical of exceptional cycles of fresh-snow avalanches in the northern Alps are investigated using the numerical avalanche-hazard forecasting procedure of Météo-France. Sensitivity tests are performed on the events of February 1999 in the Chamonix France region, and resulting snowpack instability modeled at the massif scale is compared using adapted new indices and maps. Our results complete conclusions of earlier observation-based studies by providing new insights into the snow and weather conditions of February 1999. The large avalanches mainly resulted from large and very unstable fresh-snow accumulations. Moreover, the snowpack instability was increased locally by wind transport of light and fresh snow in February. The mechanical weaknesses resulting from the weather conditions prior to February were a key factor in explaining the unusual volumes of these avalanches. This study suggests that the operational numerical SAFRAN/Crocus/ MÉPRA (SCM) chain provides reliable forecasts of extreme new-snow avalanche situations at the massif scale, but that local-scale simulations are still needed to improve the efficiency of risk mitigation and civil protection policies.
Formation of air clathrate hydrates in polar ice sheets: heterogeneous nucleation induced by micro-inclusions
Authors: Ohno Hiroshi , Lipenkov Vladimir Ya. , Hondoh Takeo 
Published: January 2011

AbstractTo investigate factors influencing nucleation of air clathrate hydrates in polar ice sheets, we have performed high-resolution mapping of the distributions of soluble impurities, air bubbles and air- hydrate crystals versus depth in the Dome Fuji Antarctic ice. Significant correlation observed between the concentrations of air inclusions and impurities in ice along with frequent occurrence of impurities inside hydrate crystals suggest that micro-inclusions promote hydrate nucleation in the ice matrix. Our observations also show that the diffusive macroscopic-scale redistribution of air constituents in ice in the bubble-hydrate transition zone is controlled by the original sedimentary layering of soluble impurities acting as nucleation helpers. The results of this study are important for the correct interpretation of high-resolution gas analyses of ice cores and for better understanding the global bubble-to-hydrate transformation process in polar ice sheets.
Magnesium methanesulfonate salt found in the Dome Fuji (Antarctica) ice core
Authors: Sakurai Toshimitsu , Ohno Hiroshi , Genceli F. Elif , Horikawa Shinichirou , Iizuka Yoshinori , Uchida Tsutomu , Hondoh Takeo 
Published: January 2011

AbstractUsing micro-Raman spectroscopy, we identified the chemical forms of methanesulfonate salt particles in reference samples of the Dome Fuji (Antarctica) ice core. We found only (CH3SO3)2Mg nH2O among methanesulfonate salts, and this salt particle is most prevalent in the Last Glacial Maximum (LGM) ice. We suggest that during the LGM, (CH3SO3)2Mg nH2O may have formed in the atmosphere through the chemical reaction of CH3SO3H with sea salts, but probably not in the firn and ice due to the neutralization of acid in LGM ice of inland Antarctica.
Meteoric and marine ice crystal orientation fabrics from the Amery Ice Shelf, East Antarctica
Authors: Treverrow Adam , Warner Roland C. , Budd William F. , Craven Mike 
Published: January 2011

AbstractThe northwestern sector of the Amery Ice Shelf, East Antarctica, has a layered structure, due to the presence of both meteoric ice and a marine ice layer resulting from sub-shelf freezing processes. Crystal orientation fabric and grain-size data are presented for ice cores obtained from two boreholes ˜70 km apart on approximately the same flowline. Multiple-maxima crystal orientation fabrics and large mean grain sizes in the meteoric ice are indicative of stress relaxation and subsequent grain growth in ice that has flowed into the Amery Ice Shelf. Strongly anisotropic single-maximum crystal orientation fabrics and rectangular textures near the base of the ˜200 m thick marine ice layer suggest accretion occurs by the accumulation of frazil ice platelets. Crystal orientation fabrics in older marine ice exhibit vertical large circle girdle patterns, influenced by the complex stress configurations that exist towards the margins of the ice shelf. Post-accumulation grain growth and fabric development in the marine ice layer are restricted by a high concentration of brine and insoluble particulate inclusions. Differences in the meteoric and marine ice crystallography are indicative of the contrasting rheological properties of these layers, which must be considered in relation to large-scale ice-shelf dynamics.
Spatio-temporal variability in elevation changes of two high-Arctic valley glaciers
Authors: Barrand Nicholas E. , James Timothy D. , Murray Tavi 
Published: January 2011

AbstractUncertainties in estimates of glacier and ice-cap contribution to sea-level rise exist in part due to poor quantification of mass-balance errors, particularly those resulting from extrapolation of sparse measurements. Centre-line data are often assumed to be representative of the glacier as a whole, with little attention paid to extrapolation errors or their effect on mass-balance estimates. Here we present detailed digital elevation model (DEM) measurements of glacier-wide elevation changes over the last ~40 years at two glaciers on Svalbard, Norwegian Arctic. Austre Br0ggerbreen and Midtre Lovenbreen are shown to have lost 27.54 ± 0.98 and 9.65 ± 0.76 × 107m3 of ice, respectively, between 1966 and 2005, findings that we relate to trends in average summer air temperatures and winter accumulation. These volume losses correspond to geodetic balances of -0.58 ± 0.03 and -0.41 ± 0.03 mw.e. a-1, respectively. Our analysis revealed high spatial complexity in patterns of elevation change, varying between glaciers, between measurement intervals and within and between elevation bins. Balances from extrapolated centre-line geodetic data were the same (within errors) as those from full-coverage DEM differencing in the majority of comparisons, yet significantly underestimated balance in three instances. Additionally, field mass balance from centre-line ablation stake data underestimated balances from full-coverage geodetic measurements during three of six measurement periods. These findings may support the hypothesis that field measurements underestimate Svalbard glacier mass loss, at least partly as a result of the failure of centre-line measurements to account for glacier-wide variations in ablation. Our results demonstrate the importance of deriving accurate interpolation functions and constraining extrapolation errors from sparse measurements.
Uncertain Environments: Natural Hazards, Risk and Insurance in Historical Perspective
Authors: LÜBKEN Uwe , Mauch Christof 
Published: January 2011

Abstract
Natural catastrophes are not just sudden events; they are also embedded in historical patterns of vulnerability and resilience. In modern societies, risk is one of the most important principles applied to the challenges that natural hazards pose and insurance is an ever more important tool of risk management. The contributions to this special issue of Environment and History all stress the fact, however, that environmental risk is not simply a phenomenon 'out there' but the result of social, scientific, economic and cultural processes. They also illustrate that the understanding of risk varies over time.
Forestation and its Discontents: The Invention of an Uncertain Landscape in Southwestern France, 1850-Present
Authors: Temple Samuel 
Published: January 2011

Abstract
This article examines the politics of forestation and fire prevention in the Landes region of France, one of the largest contiguous forests in Europe. It argues that the monoculture forest of maritime pine, promoted by both the French state and local landowners in the nineteenth century, represents an uncertain environment that has eluded the control of its creators. The economic, social and political costs of this engineered forest, it is suggested, reflect the cultures of risk that have accompanied territorial transformation schemes in modern France.
From an Act of God to an Insurable Risk: The Change in the Perception of Hailstorms and Thunderstorms since the Early Modern Period
Authors: Oberholzner Frank 
Published: January 2011

Abstract
Despite the welcome growth in the literature on historical disasters, there has been no recent study into the change in the perception of serious storms and in particular hailstorms that took place during the Early Modern period. With the help of selected sources, some of which have hitherto never been the subject of historical research, this essay will aim to illuminate the main steps that contributed towards what was effectively a demystification of the 'wrath of God'. The essay will set the interpretation of hailstorms and the strategies for coping with them against the background of the predominant theological and scientific opinions of the day. It concludes with a short survey of cameralist suggestions towards a comprehensive hail insurance system.
From Wood to Stone: The Risk Management of Swiss Re in The Sundsvall Fire 1888
Authors: Rohland Eleonora 
Published: January 2011

Abstract
Through the lens of the Swiss Reinsurance Company's (today Swiss Re) nineteenth century correspondence, the Swedish and international (re-)insurance industry's risk management after the devastating fire of Sundsvall, Sweden on June 25, 1888 unfolds. The article focuses on the Swiss Reinsurance Company's post disaster 'risk-shaping' and the formation of reinsurance lobby-groups in the aftermath of the disaster. It argues that even the insurance industry's concept of 'objective risk' is not static but fluid and open to negotiation within the insurance system. Since the insurance industry works on the interface between the natural and the built environment it can influence directly how societies interact with nature. The article argues furthermore, that perceiving fire merely as a man-made hazard without considering its 'natural' context falls short of an accurate analysis, in particular concerning 'catastrophic loss' (i.e. large-scale loss) affecting (re-)insurers' geographical risk distribution.
Sharing the Risk of Hail: Insurance, Reinsurance and the Variability of Hailstorms in Switzerland, 1880-1932
Authors: Mauelshagen Franz 
Published: January 2011

Abstract
This paper describes part of the early history of crop insurance in Switzerland as a process of adaptation to the hazard of hail. It argues that insurance is a means of socialising hazard through risk sharing and, therefore, that adaptation is an active process influenced by various decisions both within and outside the insurance market. These decisions are as much a part of the story as is the variability of hailstorms in Switzerland. A period of more extreme hailstorms, which challenged insurance provision, occurred between 1920 and 1930 and was linked by reinsurers with climatic change. Examination of this time period will lead to a discussion of insurance in the context of the current debate on global warming, its projected impacts, and possible strategies of adaptation.
Le Troisième Age dans la population française
Authors: Beteille René 
Published: January 2011

Die Zahlen der über 65 jährigen beträgt 13,6 % der französischen Bevölkerung, d. h. über 7 Millionen Menschen. Die Belastung im Verhältnis zu den Berufsläligen nimmt seil dem Kriegsende ständig zu.
Geographisch gesehen sind die Reniner unausgeglichen verteilt : gewisse Departments sind uberaltert, in anderen dagegen ist die Bevölkerung jünger. Darüber hinaus sind die Frauen zahlreicher als die Männer.
Durch die Renlenfrage, die sozialen Enrichtungen (Altenheime, Pflege- heime u.s.w.) und einen spezifischen Markt ist ein neuer Wirtschaftszweig entstanden.
Les pêches maritimes britanniques : une activité en crise
Authors: Fournet Philippe 
Published: January 2011

SUMMARY
Already seriously affected by the stagnation of domestic demand and by the over exploitation of certain species, the British maritime fishing industry has very poorly supported the effects of the recent energy crisis. Furthermore, the generalization of the 200 mile fishing limit in the North Atlantic has deprived British fleet owners of fishing areas that are particularly rich in commercial types of fish. In addition, all of the fishing ports where industrial fishing is conducted have been struck by the same stagnation : the offices of many ship and boat owners are definitely closed, a large part of the trawler fleet has been disbanded, the fish transformation industries are inadequately supplied in spite of an increase in imports, and many of the unemployed fishermen are finding it extremely difficult to adjust to conditions ashore. This situation accounts for the attitude of London which is refusing to make of its 200 miles limit a community area, as is desired by the C.E.E. , and is asking for an exclusive fishing zone which would be capable of reviving its deep sea fishing activities and of maintaining an active coastal fishing program. Finally, in an attempt to save their high sea fishing fleet, the shipowners are attempting to create joint ventures overseas, and they have their eyes set on certain fishing zones in the Southern Hemisphere that are still under-exploited.
Géographie fiscale en milieu urbain : l'exemple de la ville de Nantes
Authors: Rapetti Danielle 
Published: January 2011

RÉSUMÉ
L'accès légal depuis 1974 aux « Registres de publicité des impositions sur les revenus des personnes privées » ouvre la voie aux investigations les plus fines en géographie fiscale. La ville de Nantes sert de cadre à la mise au point d'une méthode d'analyse reposant sur les notions de « critère d'aisance » et de « profil fiscal » définies pour chaque rue. Il en résulte la possibilité d'établir un véritable réseau fiscal hiérarchisé que l'on peut considérer comme une importante composante du tissu urbain.