New seismotectonic data from an intraplate region: focal mechanisms in the Armorican Massif (northwestern France)

Autor: D. Amorèse, Marianne Font, Philippe Volant, M. Lecornu, J.-P. Santoire, J.-L. Lagarde, A. Walker
Přispěvatelé: Morphodynamique Continentale et Côtière (M2C), Centre National de la Recherche Scientifique (CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), British Geological Survey (BGS), Laboratoire de Détection et de Géophysique (CEA) (LDG), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Morphodynamique Continentale et Côtière ( M2C ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Rouen Normandie ( UNIROUEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Caen Normandie ( UNICAEN ), Normandie Université ( NU )
Rok vydání: 2000
Předmět:
010504 meteorology & atmospheric sciences
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
Induced seismicity
010502 geochemistry & geophysics
01 natural sciences
[ SDU.STU.GP ] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
[ PHYS.PHYS.PHYS-GEO-PH ] Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
Geochemistry and Petrology
Orientation (geometry)
fault plane solutions
seismotectonics
Thrust fault
0105 earth and related environmental sciences
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics
geography
Focal mechanism
geography.geographical_feature_category
Seismotectonics
[ SDU.STU.TE ] Sciences of the Universe [physics]/Earth Sciences/Tectonics
Massif
Strike-slip tectonics
Normandy
Geophysics
Intraplate earthquake
Jersey
seismicity
Geology
Seismology
Zdroj: Geophysical Journal International
Geophysical Journal International, Oxford University Press (OUP), 2000, 143 (3), pp.837-846. ⟨10.1046/j.0956-540X.2000.01285.x⟩
Geophysical Journal International, 2000, 143 (3), pp.837-846. ⟨10.1046/j.0956-540X.2000.01285.x⟩
Geophysical Journal International, Oxford University Press (OUP), 2000, 143 (3), pp.837-846. 〈10.1046/j.0956-540X.2000.01285.x〉
ISSN: 1365-246X
0956-540X
Popis: International audience; Focal mechanism solutions are determined for 11 small intraplate earthquakes that occurred between 1990 and 1998 in Normandy and the Channel Islands. These mechanisms are obtained from the P-wave first-motion polarities recorded by stations from local and regional seismic networks. The accuracy of each hypocentral location is closely examined and the quality of each fault plane solution is discussed by considering the influence of the velocity structure. The predominant feature of the computed focal mechanisms is the relatively widespread near-horizontal NE–SW T-axis orientation. Horizontal P-axes strike roughly NW–SE. Mechanism solutions for the earthquakes in the Avranches region show left-lateral strike slip on a NNW–SSE fault zone. For the overall region, it seems that nodal planes of normal faulting solutions trend NW–SE or WNW–ESE, whereas those of thrust faulting solutions trend NE–SW. This is in agreement with the general regional stress pattern. The NE–SW normal fault plane solution of the 1990 Jersey event is unique because it is not consistent with the regional style of faulting.
Databáze: OpenAIRE
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