Istituto Nazionale di Geofisica e Vulcanologia SCIENTIFIC EXPLOITATION OF EO DATA FOR EARTHQUAKES AND TECTONICS Stefano Salvi National Earthquake Center Istituto Nazionale di Geofisica e Vulcanologia - Roma Models for scientific exploitation of EO Data – ESA-ESRIN Oct. 2012

Istituto Nazionale di Geofisica e Vulcanologia 1. Processes of the seismic cycle. 2. Earthquake interaction. 3. Earthquake preparation processes. 4. Earthquake-induced hazards. Some challenges in tectonics and earthquake science

Istituto Nazionale di Geofisica e Vulcanologia 1 – Processes of the seismic cycle Long term monitoring of crustal strain before and after an earthquake is necessary to understand the large scale processes that bring tectonic stresses to rupture the crust and cause earthquakes, and to understand the rheology of the lower crust and upper mantle. EO contributing data: SAR, CGPS. Main requirement: long term monitoring continuity

Istituto Nazionale di Geofisica e Vulcanologia 2 - Earthquake interaction Temporally dense geodetic time series are needed to investigate the effects of stress redistribution after large earthquakes, and the possible implications for the triggering of large earthquakes on nearby faults. EO contributing data: SAR, CGPS

Istituto Nazionale di Geofisica e Vulcanologia 2 - Earthquake interaction The New Zealand seismic sequence The Mw 7.1 Darfield mainshock was followed by 5 more Mw > 6 events, occurring during 1.5 years, along an E-W alignment.

Istituto Nazionale di Geofisica e Vulcanologia 2 - Earthquake interaction The New Zealand seismic sequence Using ENVISAT, ALOS, and COSMO-SkyMed data, and InSAR, and offset tracking techniques, the ground deformation of three of the seismic sources was measured and then modeled

Istituto Nazionale di Geofisica e Vulcanologia 2 - Earthquake interaction The New Zealand seismic sequence The earthquakes had a clear interaction: the first earthquake increased the stress level on the faults of the second earthquake, and together they increased the stress level on the fault of the third event Atzori et al., 2012 Main requirement: ad hoc acquisitions on post seismic phase

Istituto Nazionale di Geofisica e Vulcanologia Monitoring geophysical and geochemical parameters over tectonically active areas in many different geological environments, with high spatial and temporal resolution and accuracy, might unveil important phenomena which are thought to occur during the earthquake preparation phases, at medium to short timescales. EO contributing data: SAR, CGPS, thermal IR, electromagnetic. 3 - Earthquake preparation processes

Istituto Nazionale di Geofisica e Vulcanologia During the Emilia seismic sequence, the M 5.9 mainshock was followed, 9 days later, by an M 5.8 aftershock. We subtracted from a Radarsat interferogram containing the total ground deformation of the two events, a COSMO-SkyMed interferogram containing the deformation due to the second event only. They have the same LoS. 3 - Earthquake preparation processes Deformation transient before the M 5.8 Emilia earthquake Rsat all events CSK 2nd event - = Courtesy of TRE

Istituto Nazionale di Geofisica e Vulcanologia We thus obtain the ground deformation occurred just before the second earthquake. Besides the clear co-seismic pattern of the mainshock, a further deformation pattern become evident (black circle). There is apparently no comparable size aftershock connected to such signal, which in fact is well explained by foreslip on the same fault plane which later originated the M 5.8 aftershock. 3 - Earthquake preparation processes Deformation transient before the M 5.8 Emilia earthquake = Pezzo et al., 2012 Main requirement: temporally dense monitoring (days)

Istituto Nazionale di Geofisica e Vulcanologia Earthquake ground shaking and stress transfer may trigger a number of geological effects which increase the co-seismic and post-seismic hazard, e.g. Volcanic eruptions, tsunamis, gravitational sliding, surface faulting and collapse, soil liquefaction, soil gas release, etc. EO sensors can provide important information to understand the details of some of these effects and their driving processes. EO contributing data: SAR, CGPS, optical, thermal, electromagnetic. 4 – Earthquake induced hazards

Istituto Nazionale di Geofisica e Vulcanologia Several such effects are well mapped by the 5 m resolution COSMO interferogram 4 – Earthquake induced hazards Local gravitational deformation triggered by L’Aquila eq.

Istituto Nazionale di Geofisica e Vulcanologia 4 – Earthquake induced hazards Local gravitational deformation triggered by L’Aquila eq. ~5 cm displacement triggered by the earthquake on ancient slope deformations A B C Major trench zone A B C Moro et al., 2011 Main requirement: high spatial resolution data (and comparable resolution DEM)

Istituto Nazionale di Geofisica e Vulcanologia 1. EO data acquisition 2. EO data access 3. EO data analysis and information retrieval Some requirements and recommendations for EO data exploitation – Earthquakes and Tectonics

Istituto Nazionale di Geofisica e Vulcanologia Scientific User’s requirements: 1 - EO data acquisition 1.long term mission continuity 2.stable sensor characteristics and acquisition geometries 3.community interaction with Agencies for site selection 4.flexibility of acquisition geometry for shorter monitoring periods (e.g. post-seismic phase) 5.large swaths and medium resolution (some applications) 6.high resolution EO data and DEMs (other applications)

Istituto Nazionale di Geofisica e Vulcanologia Possible actions: 1 - EO data acquisition 1.Integrated (and cooperative) long term global observation strategy 2.Synergetic use of different missions (e.g. to make up for variable spatial/temporal resolution and coverage gaps) 3.Intelligent resource management (different spatial/temporal sampling can be used on different areas, e.g. InSAR over Emilia vs Dead Sea) Problems: 1.loss of monitoring continuity (change of sensor/platform) 2.conflicting requirements (high/low resolutions) 3.conflicting acquisition requests (science/commercial/operation/defense)

Istituto Nazionale di Geofisica e Vulcanologia Scientific User’s requirements: 2 - EO data access 1.data at no cost 2.standard interfaces for data access (across missions) 3.standardisation of formats (across missions) 4.short access time

Istituto Nazionale di Geofisica e Vulcanologia Possible actions: 2 - EO data access 1.inter-agency agreements for cost reduction 2.direct satellite download 3.provide remote processing capability to scientific community (e.g. GPOD) 4.harmonisation of formats and interfaces/procedures for data access Problems: 1.costly data for some missions 2.delays in image availability 3.too many different formats 4.different data access procedures and interfaces

Istituto Nazionale di Geofisica e Vulcanologia Scientific User’s requirements: 3 - EO data analysis and information retrieval 1.funding for research projects 2.EO results validation 3.access to image processing tools 4.specific high level knowledge and processing resources

Istituto Nazionale di Geofisica e Vulcanologia Possible actions: 1.fund permanent training (and mobility) for Earth scientists 2.fund high level university education 3.provide free knowledge and technical help to the community (remote processing, help desk on specific applications) 4.issue scientific research calls, also coordinated among different Agencies 5.stimulate community building Problems: 1.knowledge gap between development of EO technology and Earth scientists (especially in underdeveloped countries) 2.also, shortage of human and technical resources limits the diffusion of EO data use in many disciplines 3.difficult access to validation data for error estimation (either previous EO results or in situ data) 3 - EO data analysis and information retrieval

Istituto Nazionale di Geofisica e Vulcanologia Thank you for your attention and a special thank to Gemma Manoni – ASI for the fruitful discussions