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Rockfalls and debris avalanches triggered by earthquakes during the 2010–2011 Canterbury earthquake sequence killed five people and caused an estimated US$400 million in damages. In total, about 200 dwellings were directly impacted by some of the ~6000 rockfalls and debris avalanches that occurred across the Port Hills of Christchurch. This research presents the results of the analysis of a high-quality database of 61 individual rockfall impacts on 29 dwellings in the Port Hills of Christchurch, New Zealand. Dwellings in the Port Hills are typically simple timber-frame structures with wooden or unreinforced masonry cladding, comparable to most dwellings across New Zealand, North America, Australia, and elsewhere. Rockfall impacts on dwellings in this study were observed to follow a power law relationship between kinetic energy and (1) the runout distance into and through the dwelling and (2) the impacted area within the dwelling. The results have been quantified and are presented as a damage proportion, which is defined as the proportion of the area affected by an individual rock block inside the dwelling divided by the total area of the dwelling. These data provide a fundamental input for rockfall risk analysis and will allow the losses from rockfall impacts to be better constrained. 相似文献
134.
Gerardo Herrera Rosa María Mateos Juan Carlos García-Davalillo Gilles Grandjean Eleftheria Poyiadji Raluca Maftei Tatiana-Constantina Filipciuc Mateja Jemec Auflič Jernej Jež Laszlo Podolszki Alessandro Trigila Carla Iadanza Hugo Raetzo Arben Kociu Maria Przyłucka Marcin Kułak Michael Sheehy Xavier M. Pellicer Charise McKeown Graham Ryan Veronika Kopačková Michaela Frei Dirk Kuhn Reginald L. Hermanns Niki Koulermou Colby A. Smith Mats Engdahl Pere Buxó Marta Gonzalez Claire Dashwood Helen Reeves Francesca Cigna Pavel Liščák Peter Pauditš Vidas Mikulėnas Vedad Demir Margus Raha Lídia Quental Cvjetko Sandić Balazs Fusi Odd Are Jensen 《Landslides》2018,15(2):359-379
Landslides are one of the most widespread geohazards in Europe, producing significant social and economic impacts. Rapid population growth in urban areas throughout many countries in Europe and extreme climatic scenarios can considerably increase landslide risk in the near future. Variability exists between European countries in both the statutory treatment of landslide risk and the use of official assessment guidelines. This suggests that a European Landslides Directive that provides a common legal framework for dealing with landslides is necessary. With this long-term goal in mind, this work analyzes the landslide databases from the Geological Surveys of Europe focusing on their interoperability and completeness. The same landslide classification could be used for the 849,543 landslide records from the Geological Surveys, from which 36% are slides, 10% are falls, 20% are flows, 11% are complex slides, and 24% either remain unclassified or correspond to another typology. Most of them are mapped with the same symbol at a scale of 1:25,000 or greater, providing the necessary information to elaborate European-scale susceptibility maps for each landslide type. A landslide density map was produced for the available records from the Geological Surveys (LANDEN map) showing, for the first time, 210,544 km2 landslide-prone areas and 23,681 administrative areas where the Geological Surveys from Europe have recorded landslides. The comparison of this map with the European landslide susceptibility map (ELSUS 1000 v1) is successful for most of the territory (69.7%) showing certain variability between countries. This comparison also permitted the identification of 0.98 Mkm2 (28.9%) of landslide-susceptible areas without records from the Geological Surveys, which have been used to evaluate the landslide database completeness. The estimated completeness of the landslide databases (LDBs) from the Geological Surveys is 17%, varying between 1 and 55%. This variability is due to the different landslide strategies adopted by each country. In some of them, landslide mapping is systematic; others only record damaging landslides, whereas in others, landslide maps are only available for certain regions or local areas. Moreover, in most of the countries, LDBs from the Geological Surveys co-exist with others owned by a variety of public institutions producing LDBs at variable scales and formats. Hence, a greater coordination effort should be made by all the institutions working in landslide mapping to increase data integration and harmonization. 相似文献
135.
In preparation for the Rosetta mission, the location and widths of gravitational resonances surrounding a regularly shaped and possibly complex rotating body are mapped following the second fundamental model of resonance. It is found that for uniaxial rotation of the central body, the surrounding resonances are widest for prograde orbits. If the figure axis is tilted with respect to the spin axis of the central body, an additional number of wide resonances appear with a preference for prograde and inclined orbits, and the occurrence of initial conditions which lie in the globally connected chaotic web is significantly increased. For larger rotational excitations, it is seen how these new additional resonances overlap internally at low eccentricity for very large semi-major axes. However, with exceptions for some excited short-axis rotational modes of the central body, it is argued that most resonances vanish for retrograde orbits lying in the plane normal to the body spin, and that resonant or non-resonant stability therefore can be expected for a wide range of mean orbit eccentricities. 相似文献
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Jesper Olsen Esther Ruth Gudmundsdóttir Svante Björck Bent V. Odgaard Jan Heinemeier 《第四纪科学杂志》2010,25(5):612-616
Tephra horizons are potentially perfect time markers for dating and cross‐correlation among diverse Holocene palaeoenvironmental records such as ice cores and marine and terrestrial sequences, but we need to trust their age. Here we present a new age estimate of the Holocene Mjáuvøtn tephra A using accelerator mass spectrometry 14C dates from two lakes on the Faroe Islands. With Bayesian age modelling it is dated to 6668–6533 cal. a BP (68.2% confidence interval) – significantly older and better constrained than the previous age. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
138.
A Numerical Framework for Modeling Folds in Structural Geology 总被引:1,自引:1,他引:0
A numerical framework for modeling folds in structural geology is presented. This framework is based on a novel and recently published Hamilton–Jacobi formulation by which a continuum of layer boundaries of a fold is modeled as a propagating front. All the fold classes from the classical literature (parallel folds, similar folds, and other fold types with convergent and divergent dip isogons) are modeled in two and three dimensions as continua defined on a finite difference grid. The propagating front describing the fold geometry is governed by a static Hamilton–Jacobi equation, which is discretized by upwind finite differences and a dynamic stencil construction. This forms the basis of numerical solution by finite difference solvers such as fast marching and fast sweeping methods. A new robust and accurate scheme for initialization of finite difference solvers for the static Hamilton–Jacobi equation is also derived. The framework has been integrated in simulation software, and a numerical example is presented based on seismic data collected from the Karama Block in the North Makassar Strait outside Sulawesi. 相似文献
139.
Environmental data, particularly wave and current data, are of vital importance in offshore engineering. The needs for such data are discussed with reference to the influence of various environmental parameters on the loads of offshore structures. Data collected until now from the Norwegian continental shelf are reviewed. Furthermore, a planned data collection program is presented and discussed with respect to experience with instrumentation techniques, data recovery, and representativity, as well as interpretation and analysis gained from the present activity in this field. 相似文献
140.
Toulon is an olivine-bronzite chondrite found near Toulon, Illinois in 1962. It contains abundant, well preserved chondrules, as well as glasses that are not well devitrified. Most of the metal has been weathered out. Olivine and pyroxene are well equilibrated. We have classified it as an H5 chondrite. 相似文献