Documentary proxies and interdisciplinary research on historic geomorphologic hazards: a discussion of the current state from a central European perspective

During the last two decades, documentary data (written and iconographic sources) have been increasingly employed in geomorphologic research aiming at reconstruction of territorial distribution, temporal occurrence and social and economic impacts of various geomorphologic hazards. The goal of this paper is to broaden the previous discussion (Glade et al. The use of historical data in natural hazard assessments. Kluwer, Dordrecht, 2001) of the methodological constraints on the use of documentary data for geomorphologic hazard research. Using the interdisciplinary approach of geomorphology, historiography and medial studies, we firstly summarise the major finding of papers that have employed various types of documentary data sources to study geomorphologic hazards in different regions. In the second section, we present case studies from the Czech Republic resulting from the ongoing research project that is devoted to the assessment of the potential of documentary data to reconstruct past occurrences of and mitigation strategies for geomorphologic hazards. Finally, we discuss three main methodological issues emerging from our research: (a) problems emerging from the positivist approach to documentary data sources and the necessity for critical analyses of documentary data sources based on modern historiographic approaches, (b) constraints arising from the combination of documentary data from different spatiotemporal scales and (c) lacks in the use of documentary data to study local-based adaptation strategies to cope with geomorphologic hazards.     

极地深冰心钻探“暖冰”层钻进技术难点及对策

极地冰心分辨率高、记录时间尺度长、信息包含量大,直接记录着远古时期的大气组成,蕴藏着珍贵的古气候和古环境信息,获得年代久远的深冰心,对于重建地球的历史演化以及预测全球气候、环境的变迁具有重要意义。因此,世界各国都在竞相寻找年代久远的冰心,开展深冰心钻探工程。实践表明,由于极地冰盖深部＂暖冰＂层冰的熔点低而温度高,某些冰层的温度接近甚至达到冰的压力熔点,以至钻进速度慢、取心率低、卡钻事故频发。详细介绍了极地深冰心钻探＂暖冰＂层钻进实践,深入分析了＂暖冰＂层钻进存在的技术问题,对钻具回转切削产生的切削热对钻进的影响进行了探讨,据此提出了＂暖冰＂层钻进技术对策以及今后的研究方向,以期为我国即将开展的深冰心钻探工程和冰下基岩取心钻探工程提供一定借鉴。     

CAMAM: A Miniature Laser Ablation Ionisation Mass Spectrometer and Microscope‐Camera System for In Situ Investigation of the Composition and Morphology of Extraterrestrial Materials

Performance studies of a microscope‐camera system (MCS) and a laser ablation/ionisation mass spectrometer (LIMS) instrument (referred to here as a laser mass spectrometer or LMS) are presented. These two instruments were designed independently for in situ analysis of solids on planetary surfaces and will be combined to a single miniature instrument suite for in situ chemical and morphological analysis of surface materials on planetary bodies. LMS can perform sensitive chemical (elemental, isotope and molecular) analyses with spatial resolution close to micrometre‐sized grains. It allows for studies with mass resolution (M/ΔM) up to 800 in ablation mode (elemental composition) and up to 1500 in desorption mode (molecular analysis). With an effective dynamic range of at least eight orders of magnitude, sensitive and quantitative measurements can be conducted of almost all elements and isotopes with a concentration larger than a few ppb atoms. Hence, in addition to the major element composition, which is important for the determination of mineralogical constituents of surface materials, trace elements can also be measured to provide information on mineral formation processes. Highly accurate isotope ratio measurements can be used to determine in situ geochronology of sample material and for investigations of various isotope fractionation processes. MCS can conduct optical imagery of mm‐sized objects at several wavelengths with micrometre spatial resolution for the characterisation of morphological surface details and to provide insight into surface mineralogy. Furthermore, MCS can help in the selection of sample surface areas for further mass spectrometric analysis of the chemical composition. Surface auto‐fluorescence measurements and images in polarised light are additional capabilities of the MCS, to identify either fluorescing minerals or organic materials, if present on the analysed surface, for further investigation by LMS. The results obtained by investigations of NIST reference materials, amino acid films and a natural graphite sample embedded in silicate rock are presented to illustrate the performance of the instruments and their potential to deliver chemical information for mineral and organic phases in their geological context.     

Thermal expansion behavior of Ce2Zr2O7 up to 898 K in conjunction with structural analyses by neutron diffraction

The thermal expansion of cubic pyrochlore Ce₂Zr₂O₇ has been measured from room temperature to 898 K on polycrystalline material in conjunction with structural analyses using neutron diffraction. This compound has a thermal expansion coefficient in line with the other comparable lanthanoide pyrochlore oxides. The coefficient can be expressed as α(T) = 8.418 × 10⁻⁶ + 0.9861 × 10⁻⁹ × T. The structural refinements performed for each measured temperature showed a comparable linear evolution of the Ce–O/Zr–O distances (within 0.57%).     

Global streamflow and thermal habitats of freshwater fishes under climate change

Climate change will affect future flow and thermal regimes of rivers. This will directly affect freshwater habitats and ecosystem health. In particular fish species, which are strongly adapted to a certain level of flow variability will be sensitive to future changes in flow regime. In addition, all freshwater fish species are exotherms, and increasing water temperatures will therefore directly affect fishes’ biochemical reaction rates and physiology. To assess climate change impacts on large-scale freshwater fish habitats we used a physically-based hydrological and water temperature modelling framework forced with an ensemble of climate model output. Future projections on global river flow and water temperature were used in combination with current spatial distributions of several fish species and their maximum thermal tolerances to explore impacts on fish habitats in different regions around the world. Results indicate that climate change will affect seasonal flow amplitudes, magnitude and timing of high and low flow events for large fractions of the global land surface area. Also, significant increases in both the frequency and magnitude of exceeding maximum temperature tolerances for selected fish species are found. Although the adaptive capacity of fish species to changing hydrologic regimes and rising water temperatures could be variable, our global results show that fish habitats are likely to change in the near future, and this is expected to affect species distributions.     

Mineralogy,petrography, geochemistry,and classification of the Košice meteorite

The Ko?ice meteorite was observed to fall on 28 February 2010 at 23:25 UT near the city of Ko?ice in eastern Slovakia and its mineralogy, petrology, and geochemistry are described. The characteristic features of the meteorite fragments are fan‐like, mosaic, lamellar, and granular chondrules, which were up to 1.2 mm in diameter. The fusion crust has a black‐gray color with a thickness up to 0.6 mm. The matrix of the meteorite is formed mainly by forsterite (Fo_80.6); diopside; enstatite (Fs_16.7); albite; troilite; Fe‐Ni metals such as iron and taenite; and some augite, chlorapatite, merrillite, chromite, and tetrataenite. Plagioclase‐like glass was also identified. Relative uniform chemical composition of basic silicates, partially brecciated textures, as well as skeletal taenite crystals into troilite veinlets suggest monomict breccia formed at conditions of rapid cooling. The Ko?ice meteorite is classified as ordinary chondrite of the H5 type which has been slightly weathered, and only short veinlets of Fe hydroxides are present. The textural relationships indicate an S3 degree of shock metamorphism and W0 weathering grade. Some fragments of the meteorite Ko?ice are formed by monomict breccia of the petrological type H5. On the basis of REE content, we suggest the Ko?ice chondrite is probably from the same parent body as H5 chondrite Morávka from Czech Republic. Electron‐microprobe analysis (EMPA) with focused and defocused electron beam, whole‐rock analysis (WRA), inductively coupled plasma mass and optical emission spectroscopy (ICP MS, ICP OES), and calibration‐free laser induced breakdown spectroscopy (CF‐LIBS) were used to characterize the Ko?ice fragments. The results provide further evidence that whole‐rock analysis gives the most accurate analyses, but this method is completely destructive. Two other proposed methods are partially destructive (EMPA) or nondestructive (CF‐LIBS), but only major and minor elements can be evaluated due to the significantly lower sample consumption.     

The Montalet granite, Montagne Noire, France: An Early Permian syn-extensional pluton as evidenced by new U-Th-Pb data on zircon and monazite

Dating the magmatism in the Montagne Noire gneiss dome in the southern French Massif Central is a key point for understanding the Late Palaeozoic evolution of this part of the Variscan belt, which is characterised by compressive tectonics during the Carboniferous and extensional tectonics during Stephanian-Permian times. The Montalet granite crops out in the north-western part of the dome and was first considered as an early syntectonic intrusion related to compressive deformation. More recently, it has been dated at 327 Ma and considered as contemporaneous with the diapiric ascent of the Montagne Noire gneiss dome before the Stephanian-Permian extension. We show that in fact, this pluton was emplaced 294 ± 1 Ma ago and is therefore contemporaneous with the Stephanian-Permian extension. This age is consistent with the interpretation of the Montagne Noire Massif as an extensional gneiss dome.     

Application of potentiometric method using a cell without liquid junction to underway pH measurements in surface seawater

This study evaluated a method to carry out underway pH measurements of surface seawater by means of a cell without liquid junction using glass electrodes for hydrogen and sodium ions as follows:

Glass-electrode-Na+

Test solution (reference solution)

H+-glass-electrode

Full-size table

Table options

     

199.

The beginning heights and light curves of high‐altitude meteors     

Pavel Koten  Pavel Spurný  Ji&#x;í Borovi ka  Stephen Evans  Andrew Elliott  Hans Betlem  Rostislav &#x;tork  Klaas Jobse 《Meteoritics & planetary science》2006,41(9):1305-1320

Abstract— In this paper, we provide an overview of meteors with high beginning height. During the recent Leonid meteor storms, as well as within the regular double station video observations of other meteor showers, we recorded 164 meteors with a beginning height above 130 km. We found that beginning heights between 130 and 150 km are quite usual, especially for the Leonid meteor shower. Conversely, meteors with beginning heights above 160 km are very rare even among Leonids. From the meteor light curves, we are able to distinguish two different processes that govern radiation of the meteors at different altitudes. Light curves vary greatly above 130 km and exhibit sudden changes in meteor brightness. Sputtering from the meteoroid surface is the dominating process during this phase of the meteor luminous trajectory. Around 130 km, the process switches to ablation and the light curves become similar to the light curves of standard meteors. The sputtering model was successfully applied to explain the difference in the beginning heights of high‐altitude Leonid and Perseid meteors. We show also that this process in connection with high altitude fragmentation could explain the anomalously high beginning heights of several relatively faint meteors.     

200.

Northern Eurasia earth science partnership initiative (NEESPI), science plan overview     

Pavel Ya. Groisman  Sergey A. Bartalev  The NEESPI Science Plan Development Team 《Global and Planetary Change》2007,56(3-4):215

Northern Eurasia Earth System Partnership Initiative, NEESPI, was established to address the global change processes associated with and/or originated within Northern Eurasia as well as to study the major socially-important processes within the region. NEESPI began as a US–Russian initiative but has quickly broadened into a fully international program. Scientists from 11 countries participated in preparing the NEESPI Science Plan. Current version of the Science Plan was released for public review on the World Wide Web in summer 2004 and finalized in December 2004. This paper provides an Overview of the Plan and is based, mainly, on its Executive Summary. The Overview describes the Plan's science themes and key science questions, provides a justification of the urgency studying Northern Eurasia from the global change prospective, and outlines research strategy and tools to address NEESPI science questions, as well as projected deliverables of the Initiative.     

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The beginning heights and light curves of high‐altitude meteors

Abstract— In this paper, we provide an overview of meteors with high beginning height. During the recent Leonid meteor storms, as well as within the regular double station video observations of other meteor showers, we recorded 164 meteors with a beginning height above 130 km. We found that beginning heights between 130 and 150 km are quite usual, especially for the Leonid meteor shower. Conversely, meteors with beginning heights above 160 km are very rare even among Leonids. From the meteor light curves, we are able to distinguish two different processes that govern radiation of the meteors at different altitudes. Light curves vary greatly above 130 km and exhibit sudden changes in meteor brightness. Sputtering from the meteoroid surface is the dominating process during this phase of the meteor luminous trajectory. Around 130 km, the process switches to ablation and the light curves become similar to the light curves of standard meteors. The sputtering model was successfully applied to explain the difference in the beginning heights of high‐altitude Leonid and Perseid meteors. We show also that this process in connection with high altitude fragmentation could explain the anomalously high beginning heights of several relatively faint meteors.     

Northern Eurasia earth science partnership initiative (NEESPI), science plan overview

Northern Eurasia Earth System Partnership Initiative, NEESPI, was established to address the global change processes associated with and/or originated within Northern Eurasia as well as to study the major socially-important processes within the region. NEESPI began as a US–Russian initiative but has quickly broadened into a fully international program. Scientists from 11 countries participated in preparing the NEESPI Science Plan. Current version of the Science Plan was released for public review on the World Wide Web in summer 2004 and finalized in December 2004. This paper provides an Overview of the Plan and is based, mainly, on its Executive Summary. The Overview describes the Plan's science themes and key science questions, provides a justification of the urgency studying Northern Eurasia from the global change prospective, and outlines research strategy and tools to address NEESPI science questions, as well as projected deliverables of the Initiative.