Is there a major seismic gap in the northern Upper Rhine Graben ?

Présentation de Mustapha Meghraoui (Eost) au 2nd Workshop Résif "Aléa sismique & Shakemaps" | 29 - 31 janvier 2018, Montpellier

Transcript

1. RESIF 29-31 janvier 2018, Montpellier Is there a major seismic gap in the northern URG ? Mustapha MEGHRAOUI EOST - Ins5tut de Physique du Globe Strasbourg, France
3. RESIF 29-31 janvier 2018, Montpellier Event V: 11200-9500 B.C. Event W: 8600-7300 B.C. Event X: 6200-3200 B.C. Event Y: 2490-2210 B.C. Event Z: 500-1450 B.C. 20000BC 15000BC 10000BC 5000BC BC/AD Calibrated date BAS52 94.8% T5.C16 95.3% T5.C12 103.0% T5.C07 103.9% CW2-1 99.4% T5.S04 99.3% CW2-2 (a) 100.8% CW2-3 (a) 100.2% CW2-3 (h) 99.4% T5.C03 103.5% CW1-4a (a) 99.9% CW1-1a (a) 99.4% CW1-1a (h) 100.8% CW1-4a (h) 102.2% CW1-2 102.6% CW1-4b 100.0% CW1-3a 102.2% CW1-3b 100.3% 1356 Basel earthquake 5 events since 11200 B.C. 18 October 1356 ~ 40 isotopic dating (TL & C14) Cas de la région de Bâle Ferry et al., Geophys. J. Int. 2005
4. RESIF 29-31 janvier 2018, Montpellier Wasatch Basel, Switzerland Youngs & Coppersmith, 1985 Meghraoui et al., 2001 Characteristic Uncharacteristic ? paleoseismic data paleoseismic data Seismicity catalogues oJen do not include several seismic cycles
5. Seismicity 800 – 2006 Frechet, Meghraoui and Vogt (2011)
6. RESIF 29-31 janvier 2018, Montpellier 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 47 47.5 48 48.5 49 49.5 50 50.5 51 51.5 52 Magnitude Latitude A seismic gap in the northern Upper Rhine Graben Instrumental seismicity (1900 – 2005) Upper and lower Rhine graben When & how large ?
7. RESIF 29-31 janvier 2018, Montpellier Faille normale active sur le « gap sismique »
8. RESIF 29-31 janvier 2018, Montpellier Faille normale active (Forst) Pléistocène Supérieur (data5ons isotopiques Socle permo-triasique
9. RESIF 29-31 janvier 2018, Montpellier Faille normale min Mw 6.5 max Mw 7.2 Scenario pour un séisme modéré à fort (Mw > 6) Modèle de faille
10. RESIF 29-31 janvier 2018, Montpellier Ø  Intraplate deformation and seismic gap of Rhine graben Ø  Completeness of historical seismicity catalogues Ø  Mmax and faulting events (surface ruptures - paleoseismology) Ø  Mmax and GR distribution Ø  Implications for seismic hazard and risk assessment Conclusion (remaining issues)