Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
The island of Taiwan is affected by intense seismic activity, which includes large events as the disastrous 1999 Chi-Chi earthquake. To improve seismic hazard assessment in this area, we estimate the effect of both interseismic loading and major events since 1736 on the state of stress of major active faults. We focus our approach on western Taiwan, which is the most densely populated part of Taiwan. We pay a specific attention to faults geometry and to both interseismic and coseismic slip distributions. Our results suggest that both earthquakes and interseismic loading before 1999 increase the Coulomb stress in the north-western part of the Chelungpu fault, a region which experienced the highest coseismic slip during the Chi-Chi earthquake. More importantly our results reveal a Coulomb stress increase in the southern part of the Changhua thrust fault, below a densely populated area.
ISSN: 0094-8276

hal-00475590
https://hal.archives-ouvertes.fr/hal-00475590
DOI : 10.1029/2009GL042292

Éditeur(s) : HAL CCSD Dipartamento di Scienze della Terra, Università degli Studi di Modena
Résumé : International audience
The aim or this paper is to give an overall view of the natural hazards and risks affecting the French West Indies. These are mainly connected with hurricanes, volcanic eruptions and earthquakes which have caused several deaths and seriously weakened the local economy during the last three centuries. First of all the geological and geographical conditions which determine the natural predisposition of the French West Indies to geophysical and atmospheric hazards are described. Then the risk for the population is taken into account, both in terms of' the direct effects of the above mentioned hazards and of the side-effects, that is tidal waves, floods and mass movements. Finally the economic and social impact of natural disasters on the French West Indies and the difficulties arising in risk mitigation are shown.
Lo scopo di questo lavoro è di fornire un quadro generale dei rischi naturali che interessano le Antille Francese. Questi sono principalmente connessi con uragani, eruzioni vulcaniche e terremoti che, nel corso degli ultirni tre secoli hanno causato parecchi decessi e seriamente indebolito la economia locale. Vengono dapprima descritte le condizioni geologiche e geografiche che determinano la naturale predisposizione delle Antille Francese a minacche di tipo sia endogeno che esogeno. Viene poi considerato il rischio per la.popolazione, sia in termiini di effetti diretti dei fenomeni sopra citati che in termini di effetti marginali dovuti allo sviluppo di marernotti, alluvioni e frane. Infine viene considerato l’impatto sul tessuto sociale ed economico dei disastri di origine naturale nelle Antille Francese e le difficoltà che insorgono nella mitigazione del rischio.
The Erasmus 93-94 Programme in Geomorphology : Intensive Course in the French Antilles and Student Mobility

Droits : info:eu-repo/semantics/OpenAccess
ISBN : 88-900094-0-3
hal-01191892
https://hal.archives-ouvertes.fr/hal-01191892
https://hal.archives-ouvertes.fr/hal-01191892/document
https://hal.archives-ouvertes.fr/hal-01191892/file/D%27Ercole%201995%20-%20Natural%20hazards%20in%20the%20French%20West%20Indies.pdf

Éditeur(s) : HAL CCSD Geological Society of America
Résumé : International audience
Mechanisms that control seismic activity in low strain rate areas such as western Europe remain poorly understood. For example, in spite of low shortening rates of <0.5 mm/ yr, the Western Alps and the Pyrenees are underlain by moderate but frequent seismicity detectable by instruments. Beneath the elevated part of these mountain ranges, analysis of earthquake focal mechanisms indicates extension, which is commonly interpreted as the result of gravitational collapse. Here we show that erosional processes are the predominant control on present-day deformation and seismicity. We demonstrate, using fi nite element modeling, that erosion induces extension and rock uplift of the elevated region of mountain ranges accommodating relatively low overall convergence. Our results suggest that an erosion rate of ~1 mm/yr can lead to extension in mountain ranges accommodating signifi cant shortening of <3 mm/yr. Based on this study, the seismotectonic framework and seismic hazard assessment for low strain rate areas need to be revisited, because erosion-related earthquakes could increase seismic hazard.
ISSN: 0091-7613

insu-00817341
https://hal-insu.archives-ouvertes.fr/insu-00817341
DOI : 10.1130/G33942.1