Gulf of Cadiz: Integrated observations from nearshore sources of tsunamis: Towards an early warning system NEAREST

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1 Gulf of Cadiz: Integrated observations from nearshore sources of tsunamis: Towards an early warning system NEAREST EC Project FP6, (Contr. no ) E. Gràcia (1), N. Zitellini (2), J.J. Dañobeitia (1) and NEAREST team (1) Unitat de Tecnologia Marina (CMIMA) - CSIC, Barcelona (2) ISMAR, CNR Bologna, Italy ESONET, All Regions Workshop (BCN), 5-7 Sept. 2007

2 NEAREST Team Coordinator: ISMAR-CNR, Italy (Dr. Nevio Zitellini) Partners: University of Lisbon, Portugal Consejo Superior de Investigaciones Cientificas, Spain Alfred Wegener Institut, Germany University of West Bretagne, France INGV, Italy Technische Fachhochschule-Berlin, Germany Istituto Andaluz de Geofisica, Spain Istituto de Meteorologia, Portugal Centre National pour la Recherche Scientif. et Techn., Morocco XISTOS Development S.A., France

3 The SW Iberian Margin: Hosting AFR-EUR Convergence Focal mechanisms: Stich et al., 2005, 2007

4 The SW Iberian Margin: SWIM Bathymetric Compilation

5 The SW Iberian Margin: MCS profiles and Cores

6 The active Horseshoe Thrust Fault The Coral Patch Fault and active structures at the HAP

7 Active Fault Map of the Gulf of Cadiz Complex 1755 rupture: MPF + SVF? HF + SVF? Need to know which fault systems are seismogenically ACTIVE! MPF HF LN SVF 1755 AD km m (Stich et al, 07) GF REVERSE FAULTS: Horseshoe F: 95 km Marques Pombal F: 50 km Sao Vicente F: 100 km Guadalquivir F: 110 km STRIKE-SLIP FAULTS: Lineation N F: 125 km Lineation S F: 160 km CPRF LS

8 NEAREST: Scientific Goals 1. To identify and characterize potential tsunami sources located near shore in the Gulf of Cadiz, a highly populated area prone to earthquakes and tsunamis (e.g.1755 Lisbon EQ) where geological and geophysical knowledge has been acquired in the last 10 years 2. To detect real-time signals by a multiparameter seafloor observatory for the development of an Early Warning System (EWS) Prototype 3. To improve integrated numerical models enabling more accurate scenarios of tsunami impact and elaboration of inundation maps

9 NEAREST Workpackages WP1) Tsunami source identification WP2) Tsunami source characterization WP3) Seismological monitoring WP4) Tsunami signal detection WP5) Data integration / tsunami detection network WP6) Paleotsunami and paleoseismic records WP7) Modelling of tsunami impact in SW Portugal WP8) Feasability study and prototype for an EWS WP9) Circulatrion of ptoject inforamtion to end-users WP10) Project management

10 NEAREST WP3: Seismological monitoring Deployment of 22 BB-OBSs (AWI-Germany) for 1 year Expected results: - Monitoring offshore seismicity - Hypocenter location - Detection of EQs of M<2.5 - Insight into seismic risk - Location reliability of EWS RV Urania Cruise Leg 2: 27 August to 4 September 2007

11 NEAREST WP4: Tsunami signal detection Experiment Overview GEOSTAR-like Goal: Real-time transmission of relevant parameters of seismic and water pressure signals by GEOSTARlike station (INGV-Italy) MODUS (TUB): Guarantees the deployment & recovery of GEOSTAR Shor e station Satellite Link BUOY Acoustic transmission Transmission of parameters to the land-based Networks (Italy, Portugal, & Morocco) MODUS GEOSTAR

12 NEAREST WP4: Tsunami signal detection Pilot Experiment GEOSTAR-like Deployment of GEOSTAR-like multiparameter seafloor observatory (INGV) for 1 year Acquisition of scientific multiparametric data on a relevant seismic source site Nearly real-time warning event (seismic and sea level) identification and notification RV Urania Cruise Leg 1: 15 to 26 August 2007

13 NEAREST 1-year monitoring: Deployment August 2007 BB OBSs 85 km offshore C.S. Vicente in the Sagres Plateau at 3200 m depth GEOSTAR

14 NEAREST WP4: Tsunami signal detection GEOSTAR Instrumentation The GEOSTAR seafloor observatory is equipped with: geophysical and oceanographic sensor packages central data acquisition, control units (central clock) data processing unit Seismometer Hydrophone 3D-ACM local memory storage acoustic communication system (towards sea surface buoy) Accelerom. Guralp CMG40 Use of unique time reference for easy comparison between the signals DPG

15 GEOSTAR sensors ADCP Sensor 3-comp. broad-band Seismometer 3-comp. Accelerometer Hydrophone Pressure sensor Gravitymeter CTD + Transmissometer 3 comp. Currentmeter Sampling rate 100 Hz 100 Hz 100 Hz 15 sec 1 Hz 1min 1 min 5 Hz Acquisition Continuous Continuous Continuous Continuous Continuous Continuous Continuous Continuous

16 NEAREST Tsunami-wave Detection Procedure Based on Detection of Pressure & Seismic signals Seismometer: records on M>3.5-4 local seismic event Water pressure: detection of seafloor anomalous pressure signals Warning for events occurrence Automatic processing for computation of sea level variations (original algorithm) in case of seismic/pressure event Pressure data transmission This system can receive inputs from land and be re-programmed during the mission

17 ESONET (Contr. no ) European Seas Observatory NETwork Network of Excellence (NoE) ( ) NEAREST G. Cadiz: - Essential for seismic and tsunami hazard assessment in W-Europe - Feasibility of EWS in other areas - First step towards the installation of a permanent observatory in the G. Cadiz within the frame of the EMSO network GULF of CADIZ Major aim: To integrate in the scientific / technological European submarine Observatory Science Community