In the Obernberg valley, the Eastern Alps, landforms recently interpreted as moraines are re-interpreted as rock avalanche deposits. The catastrophic slope failure involved an initial rock volume of about 45 million m³, with a runout of 7.2 km over a total vertical distance of 1330 m (fahrböschung 10°). Cl surface-exposure dating of boulders of the avalanche mass indicates an event age of 8.6 ± 0.6 ka. A C age of 7785 ± 190 cal yr BP of a palaeosoil within an alluvial fan downlapping the rock avalanche is consistent with the event age. The distal 2 km of the rock-avalanche deposit is characterized by a highly regular array of transverse ridges that were previously interpreted as terminal moraines of Late-Glacial. 'Jigsaw-puzzle structure' of gravel to boulder-size clasts in the ridges and a matrix of cataclastic gouge indicate a rock avalanche origin. For a wide altitude range the avalanche deposit is preserved, and the event age of mass-wasting precludes both runout over glacial ice and subsequent glacial overprint. The regularly arrayed transverse ridges thus were formed during freezing of the rock avalanche deposits.
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http://dx.doi.org/10.1016/j.geomorph.2012.05.006 | DOI Listing |
Sci Rep
December 2024
Mining College, Guizhou University, Guiyang, 550025, Guizhou, China.
Mining geological disasters occur frequently in Guizhou, with mine mining and rainfall-induced avalanche geological disasters mainly, the investigation concluded that the hard rock of the overlying slide body is mostly sandstone, and it is crucial to study the physical and mechanical properties of sandstone under the action of mine mining (hereinafter referred to as the action of mining) and water action. The paper analyzes the deterioration characteristics of sandstone hydrophysical and mechanical properties under the action of mining and water. The main research results are as follows: (1) The water absorption rate of sandstone increased by 0.
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September 2024
Huadong Engineering Corporation Limited, Hangzhou, 311122, China.
A large-scale, high-speed, long-runout landslide occurred in Xinmo Village, Maoxian, Sichuan Province, China, on June 24, 2017. It was characterized by fast sliding speed, rapid volume growth, and large impact area. The dynamic process of such landslides and the influence of erosion on the dynamic process are studied by field investigation, numerical inversion and simulation.
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September 2024
Institut Terre et Environnement de Strasbourg (ITES), CNRS UMR 7063, Université de Strasbourg, Strasbourg, France.
Sensors (Basel)
November 2023
Badong National Observation and Research Station of Geohazards, China University of Geosciences, Wuhan 430074, China.
Geohazards, such as landslides, rock avalanches, debris flow, ground fissures, and ground subsidence, pose significant threats to people's lives and property [...
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2023
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139.
Deformation of all materials necessitates the collective propagation of various microscopic defects. On Earth, fracturing gives way to crystal-plastic deformation with increasing depth resulting in a "brittle-to-ductile" transition (BDT) region that is key for estimating the integrated strength of tectonic plates, constraining the earthquake cycle, and utilizing deep geothermal resources. Here, we show that the crossing of a BDT in marble during deformation experiments in the laboratory is accompanied by systematic increase in the frequency of acoustic emissions suggesting a profound change in the mean size and propagation velocity of the active defects.
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