68 research outputs found

    The Crisis of a Paradigm. A methodological interpretation of Tohoku and Fukushima catastrophe

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    Preprint, version 2. Manuscrit soumis à Earth Science Reviews, version révisée. Révision envoyée le 8 Janvier 2016.The 2011 Japanese disaster often presented as a 'new Chernobyl' accumulated the effects of earthquake, tsunami and of the subsequent nuclear accident at Fukushima. In the light of this disaster, we review methodological reasons both from geophysical and philosophical perspectives that lead the scientific and technological communities to flawed conclusions, prime cause of the disaster. The origin of the scientific mistake lies in several factors that challenge a dominant paradigm of seismology: the shallower part of the subduction was considered as weak, unable to produce large earthquakes; a complete breakage of the fault up to the sea-floor was excluded. Actually, it appears that such complete rupture of the subduction interface did characterize megathrust ruptures, but also that hazard evaluations and technical implementation were in line with the flawed con-sensual paradigm. We give a philosophical interpretation to this mistake by weighing the opposition between a prescriptive account and a descriptive account of the dynamics of research. We finally emphasize that imagination, boldness , and openness (especially to alternatives to consensual paradigms) appear as core values for research. Those values may function as both epistemic and ethical standards and are so essential as rigor and precision. Ability to doubt and to consider all uncertainties indeed appears essential when dealing with rare extreme natural hazards that may potentially be catastrophic

    Tektonika : The Community-Led Diamond Open-Access Journal for Tectonics and Structural Geology

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    Acknowledgements First and foremost, we would like to thank the tectonics and structural geology community for embracing this initiative from the start. Their feedback, enthusiasm, and passion about DOA were essential to the launch of Tektonika. The success of Tektonika would not be possible without our Associate Editors, who volunteered their time to support the editorial process, the authors, who trusted us with their research, and the reviewers, who agreed to provide their invaluable peer-review. These three pillars of the publishing system made the publication of this first issue possible. We would like to thank the University of Aberdeen, especially the Department of Geology and Geophysics in the School of Geosciences, for supporting Tektonika financially and morally. We are also grateful to Volcanica and its team for leading the way and sharing with us their know-how to set up a community-led DOAJ. Fabian Wadsworth (Volcanica) and Stephen Hicks (Seismica) are thanked for reviewing this editorial and providing valuable feedback and comments.Peer reviewedPublisher PD

    Twenty million years of continuous deformation along theKarakorum fault, western Tibet: A thermochronological analysis.

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    The role of the Karakorum fault zone (KFZ) is debated. South of 33°N, ongoing dextral-oblique slip along the SW edge of the Gar basin exhumes metamorphic and magmatic rocks of the Ayilari range. Minerals have recorded a continuum of deformation from temperatures >600–400°C down to 20 Ma of deformation along the fault. Greenschist facies deformation superimposed upon the medium- to high-grade deformation marks a kinematic change from pure dextral to dextral-normal motion associated with the onset of rapid cooling. At the regional scale, the coexistence of transtension in the Gar basin with transpression documented along the Pangong range farther north suggests another example of the ‘‘zipper tectonics'' model developed along the Red River fault. The kinematic shift induced the rise of the Ayilari range starting at 16–12 Ma and the incision of major river courses. The Indus River might have become captive of the relief at this time. The river's 120 km of apparent offset implies dextral motion at a long-term rate of ca 8.5 ± 1.5 mm/yr

    Etude des mécanismes de déformation dans le versant nord de la nappe du Mont Rose (Alpes suisses) et relation avec les grands chevauchements : approche meéhodologique de la déformation des roches gneissiques

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    Nous étudions la déformation alpine des roches de la partie Nord de la nappe du Mont Rose (Alpes Suisses) . L'analyse microtectonique et microstructurale montre que le régime de déformation est proche du cisaillement simple. La direction de cisaillement est parallèle à une linéation d'allongement très marquée de direction WNW ESE. Cette déformation ductile est reliée aux grands chevauche* ments d'âge Eocene contemporains de la collision continentale. D'un point de vue méthodologique, nous étudions les mécanismes de déformation dans les roches gneissiques (zones de cisaillement, mylonites, déformation finie).Pas de résumé

    KINEMATICS OF DUCTILE SHEARING FROM OUTCROP TO CRUSTAL SCALE IN THE MONTE ROSA NAPPE, WESTERN ALPS

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    International audienceSignificant ductile deformation has produced widespread mylonitic structures in the basement orthogneisses and the Mesozoic cover quartzites and marbles of the Monte Rosa nappe, in the inner part of the Western Alps. We summarize here the results of a detailed microstructural study at several scales of observation in the Northern part of the nappe and discuss the kinematic significance and compatibility of such results. Most of the observed deformations can be accounted for by progressive WNW-vergent shearing during and after the late Eocene, within a ductile shear zone of crustal scale. The displacement of the hanging wall may have been in excess of several tens of kilometers. However, some ESE-vergent shear criteria cannot be reconciled with this general picture and suggest that local backthrusting occurred later near the toe of the Monte Rosa nappe

    Rapid seismotectonic map of 2017/09/08 South Mexico M8.2 earthquake

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    Seismotectonic map of South Mexico Magnitude 8.2 earthquake of 2017/08/08. <br>Aim to visualize rapid and basic interpretations. <br>Robin Lacassin (IPGP), @RLacassin<br

    The crisis of a paradigm. A methodological interpretation of Tohoku and Fukushima catastrophe

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    International audienceThe 2011 Japanese disaster often presented as a 'new Chernobyl' accumulated the effects of earthquake, tsunami and of the subsequent nuclear accident at Fukushima. In the light of this disaster, we review methodological reasons both from geophysical and philosophical perspectives that lead the scientific and technological communities to flawed conclusions, prime cause of the disaster. The origin of the scientific mistake lies in several factors that challenge a dominant paradigm of seismology: the shallower part of the subduction was considered as weak, unable to produce large earthquakes; a complete breakage of the fault up to the sea-floor was excluded. Actually, it appears that such complete rupture of the subduction interface did characterize megathrust ruptures, but also that hazard evaluations and technical implementation were in line with the flawed consensual paradigm. We give a philosophical interpretation to this mistake by weighing the opposition between a prescriptive account and a descriptive account of the dynamics of research. We finally emphasize that imagination, boldness, and openness (especially to alternatives to consensual paradigms) appear as core values for research. Those values may function as both epistemic and ethical standards and are so essential as rigor and precision. Ability to doubt and to consider all uncertainties indeed appears essential when dealing with rare extreme natural hazards that may potentially be catastrophic
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