Trente-cinq ans de sismicité en Italie Centrale vue par le Réseau Sismique National de l'INGV

Présentation de Diana Latorre (INGV) aux 3èmes Rencontres Scientifiques et Techniques Résif | 10-12 octobre 2017, St Jean de Monts

Transcript

1. Trente-cinq ans de sismicité en Italie Centrale vue par le Réseau Sismique National de l’INGV D. Latorre, M. Michele, R. Di Stefano, B. Castello and L. Chiaraluce Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italie Projet de recherche financé par la Protetion Civil Italienne 3ème Rencontres Scientifiques et Technique RESIF - Saint-Jean-de-Monts, 10-12 octobre2017
2. A new catalogue of the Italian Seismicity from 1981 to 2015  The construction of a catalogue of P and S first arrivals times by merging data of the INGV Network with other permanent networks in Italy (2003-2008). New earthquake locations of events from 1981 to 2015 in Italy in a 3D velocity model To do... Integrating the time picks from temporary networks that operated during the main seismic sequencies (Colfiorito 1997, Molise 2002, L’Aquila 2009) Revising the magnitude of the catalogue
3. Talk outline  The INGV Seismic network The new catalogue of the Italian seismicity from 1981 to 2015 The relocated seismicity in Central Italy: preliminary results
4. D’Agostino, 2014 Seismotectonic settings Study area
5. Seismic monitoring in Italy From https://ingvterremoti.wordpress.com The INGV (Istituto Nazionale di Geofisica e Vulcanologia) runs the Italian National Seismic Network for monitoring earthquakes for the Italian Department of the Civil Protection The INGV Surveillance System is composed of: ~400 seismic stations (mainly broadband) ~ 110 co-located strong motion instruments -Data are transmitted in real-time at the 24/7 operations room of Rome -Hypocenter parameters (Ml>2.5) are provided to the Civil Protection into 2 minutes (automatic solution) and 30 minutes (revised solution with hand-picks of seismic phases) Data revised are available for the scientific community (http://info.terremoti.ingv.it/bsi) From https://ingvterremoti.wordpress.com
6. 1981-1996 1997-2008 2009-2016 INGV seismic stations Seismic stations of the ING and other Italian Institutions The CSI (Italian Seismicity Catalogue 1981-2002), integrates data recorded from 1981 to 2002 at the ING seismic network (actually INGV) with data from other Italian institutions (http://csi.rm.ingv.it) Permanent seismic networks in Italy
7. Relocation of the 1981-2015 dataset Di Stefano & Ciaccio, 2014 The new integrated catalogue of about 280,000 earthquakes from 1981 to 2015 is an extension of the first CSI catalogue (1981-2002). Events are located in a 3D velocity model of Italy using the nonLinear earthquake location code NonLinLoc (A. Lomax, http://alomax.free.fr) Improuvement of the INGV Seismic Network
8. Relocation of the 1981-2015 dataset Di Stefano & Ciaccio, 2014 Improuvement of the INGV Seismic Network The new integrated catalogue of about 280,000 earthquakes from 1981 to 2015 is an extension of the first CSI catalogue (1981-2002). Events are located in a 3D velocity model of Italy using the nonLinear earthquake location code NonLinLoc (A. Lomax, http://alomax.free.fr)
9. Main seismic sequences recorded in Central Italy The Altotiberina Near Fault Observatory Before the 24 August 2016, Amatrice Earthquake (Mw 6.0)
10. Chiaraluce L. pc Main seismic sequences recorded in Central Italy The Altotiberina Near Fault Observatory After the Mw6.0 Amatrice Earthquake Colfiorito 1997 (Mw 6.0) L’Aquila 2009 (Mw 6.1) 24 August 2016 Amatrice (Mw 6.0) 30 October 2016 Norcia (Mw 6.5)
11. Relocation of the 1981-2015 dataset Gubbio 1984 Mw 5.1 From Scisciani et al., 2014 Gubbio fault Gubbio fault New catalogue Old catalogue Colfiorito 1997 Mw 6.0 L’Aquila 2009 Mw 6.1 Amatrice 2016 Mw 6.0 Norcia 2016 Mw 6.5
12. Relocation of the 1981-2015 dataset MW 6.0 MW 5.6 Colfiorito 1997 Mw 6.0 Double-difference earthquake locations with data from temporary network (from Chiaraluce et al.(2003) From Mirabella et al., 2008 Gubbio 1984 Mw 5.1 New catalogue L’Aquila 2009 Mw 6.1 Amatrice 2016 Mw 6.0 Norcia 2016 Mw 6.5
13. Relocation of the 1981-2015 dataset MW 6.1 Double-difference earthquake locations with data from permanent and temporary seismic networks L’Aquila 2009 Mw 6.1 Earthquake locations in the velocity model of the Altotiberina area with data from permanent and temporary seismic networks (from Latorre et al., 2016) The 2013-2014 Gubbio-Pietralunga seismic swarm Norcia 2016 Mw 6.5 Colfiorito 1997 Mw 6.0 Amatrice 2016 Mw 6.0
14. Relocation of the 1981-2015 dataset Norcia 2016 Mw 6.5 Colfiorito 1997 Mw 6.0 Amatrice 2016 Mw 6.0 L’Aquila 2009 Mw 6.1
15. Relocation of the 1981-2015 dataset + 2016 Norcia 2016 Mw 6.5 Colfiorito 1997 Mw 6.0 Amatrice 2016 Mw 6.0 L’Aquila 2009 Mw 6.1 We include the Amatrice 2016 seismic sequence
16. Main sequencies and background seismicity Colfiorito 1997 Mw 6.0 Gubbio-Pietralunga Background seismicity Colfiorito 1997 L’Aquila 2009 Amatrice-Visso-Norcia 2016
17. Amatrice 2016 Mw 6.0 Campotosto L’Aquila 2009 Mw 6.1 Background seismicity Colfiorito 1997 L’Aquila 2009 Amatrice-Visso-Norcia 2016 From Chiaraluce et al., 2017 L’Aquila 2009 Mw 6.1 ? Main sequencies and background seismicity
18. Seismicity from 2009 to 2015
19. Some remarks  The analysis of the new catalogue of the Italian Seismicity allows us to improve the “long term” picture of the background seismicity. We need to understand the role of this background seismicity with respect to the main seismic sequencies and the tectonic context.  We need to integrate data from temporary networks to improve the quality of the hypocenter solutions  We need to improve the 3D model of the first 20 km of the crust
20. Thank you 3ème Rencontres Scientifiques et Technique RESIF - Saint-Jean-de-Monts, 10-12 octobre2017