Esdeveniments

Falles actives, terratrèmols i tsunamis al sistema de l'Arc de Gibraltar

8 Juny 2018
12:15
Ubicació: 
Sala d'Actes
Impartida per: 
Dr. Laia Gràcia i Mont
Filiació: 
Departament de Geociències Marines, Institut de Ciències del Mar

Summary

Geological hazards, such as earthquakes and tsunamis, are a major societal concern. Seismogenic faults may be silent in the instrumental and historical periods, and their seismic potential may remain inadvertently hidden, especially in areas of slow tectonic deformation with faults able to generate large-magnitude earthquakes (Mw > 6) with long recurrence intervals (103-104 years). This is the case of the active faults in the Gibraltar Arc System (Alboran Sea and Gulf of Cadiz), which hosts the convergent boundary between the Iberian and Nubia plates (4.5-5.6 mm/yr). Our dataset results from an integration of acoustic and seismic data acquired with a multiscale approach, utilizing AUV near-bottom bathymetry, shipboard bathymetry, high-resolution seismics and deep penetration multichannel seismics (MCS). We follow a multi-scale approach to characterize and built realistic marine fault source models from selected reverse and strike-slip fault systems in the Gulf of Cadiz (Marques de Pombal, Lineament South) and Alboran Basin (Carboneras, Yusuf and Al-Idrissi FS). The present-day crustal deformation of the south Iberian margin is driven by the NW-SE convergence (4.5-5.6 mm/yr) between the Nubia and Eurasian plates. This convergence accommodates over a wide deformation zone with significant activity south of the Iberian Peninsula, which includes the Gulf of Cadiz (Atlantic) and the Alboran Sea (Western Mediterranean). Here, instrumental seismicity is characterized by seismic events of low to moderate magnitude (Mw < 5.5). Nevertheless, large destructive earthquakes (Intensity IX-X and up to Mw 8.5) occurred in the region as revealed by historical and instrumental records. According to fault trend, geometry and time of activity, fault systems divide in different segments that if linked, may have the potential to generate large earthquakes and associated tsunamis.

 

Brief biography

Eulàlia Gràcia Mont, Senior researcher at the Institute of Marine Sciences of CSIC since 2008. She did a joint PhD in Geology between the UBO/IFREMER (France) and University of Barcelona (1992-1996), Postdoctoral fellow at IFREMER (1996), Marie Curie postdoctoral fellow at National Oceanography Centre, UK (1996-1998), Postdoc at Institute of Earth Sciences "Jaume Almera" (CSIC) (1999-2001), researcher at Marine Technology Unit (CSIC) (2002-2008). Specialist in marine geosciences with 20 years of experience applied to active processes in mid-ocean ridges and continental margin environments, sedimentological and physical properties of gas hydrate‐rich sediments, continental margin deformation, active tectonics, marine paleoseismology and geological hazards (earthquakes, slides, tsunamis). She participated in 15 EU projects, in 54 National and European/International projects of marine geosciences, being PI in 28 of them. She sailed in 24 oceanographic cruises and chief scientist in 6 of them, and Director of 8 PhD thesis (5 finished, 3 ongoing) and 12 Master thesis. She is author and co‐author of 129 scientific publications, 78 in SCI journals, and more than 315 presentations in international meetings. Eulàlia has been awarded by the “Kirk Bryan Award” of the Geological Society of America (2016) and the “Doctor Honoris Causa” by the University of Brest - UBO (2018).