J M MIRANDA UNIVERSITY OF LISBON THE USE OF REMOTE SENSING FOR EARTHQUAKE RISK ASSESSMENT AND MITIGATION

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1 1 THE USE OF REMOTE SENSING FOR EARTHQUAKE RISK ASSESSMENT AND MITIGATION

2 2 the observation of strong ground motion and aftershock sequences as well as the investigation of the destruction from these earthquakes [ ] provide seismology and earthquake engineering with informative and valuable data, experiences and lessons, and raise some important scientific problems. Application of new technologies such as GIS, GPS and remote sensing, among others, has been shown to be of significant help in the study of seismic hazard and risk. IASPEI Commission on Earthquake Hazard, Risk and Strong Ground Motion (IASPEI, 2004):

3 3 THE EARLY YEARS The 2004 Sumatra earthquake and tsunami, in particularly, improved the public and political awareness of the risks raised by the rapid development of huge urban areas, particularly in regions where the geo-physical risks are high. The evaluation of the economic cost of natural catastrophes is a modern concern mainly because they affect dramatically the macroeconomy of countries, generating a domino effect as a consequence of the increasing relationships between national economies.

4 4 THE EARLY YEARS Limitations: coarse spatial resolution of the first imagery series, lack of physical models to relate earthquake processes with quantities measured by RS sensors limited the use of RS. Strategy: Side Looking Radar, a non-optical imagery, was used in one of the first attempts to use RS on seismic risk mitigation (Kedar and Hsu, 1972)

5 5 PRE-SEISMIC PHASE TECTONIC HAZARD Geological Mapping: In highly rugged terrain conventional geological mapping is a Herculean task. Rock exposures and structures are often studied only at a few places and later interpolations between observations are made

6 6 PRE-SEISMIC PHASE TECTONIC HAZARD Satellite images Give synoptic view, Assure high spatial and spectral resolution, Allow the identification of deformation structures having tectonic significance and Are the best possible interpolator.

7 7 PRE-SEISMIC PHASE TECTONIC HAZARD RS imagery can be processed to extract lineation or drainage patterns that can be interpreted in terms of neo-tectonic activity and even horizontal compressive stress estimations.

8 8 PRE-SEISMIC PHASE TECTONIC HAZARD RS imagery can be used to update geological cartography.

9 9 PRE-SEISMIC PHASE TECTONIC HAZARD Comparison with ground truth: J M MIRANDA UNIVERSITY OF LISBON

10 10 PRE-SEISMIC PHASE SOIL EFFECTS Geomorphology studies, very import to establish the vulnerability of geological landscapes even if they largely benefit from remote sensing techniques, still largely rely on systematic field work directed to the measure scarp offsets, identify zones of fresh, determine the amplitude of vertical displacements, etc

11 11 PRE-SEISMIC PHASE RADIOMETRIC CONTENT J M MIRANDA UNIVERSITY OF LISBON

12 12 PRE-SEISMIC PHASE SOIL EFFECTS One of the most serious soil phenomena that are a consequence of seismic loading is soil liquefaction. It happens when the effective stress reduces to zero as a result of transient or cyclic perturbation of poorly consolidated soil that looses cohesion. A Liquefaction sensitivity index (LSeI) has been proposed based on pre and post earthquake LISS-III and WiFS data sets (Ramakrishna et.al., 2003). Ground evidence of liquefaction; IRS-WiFS Difference FCC of Kachchh showing spatial extent of liquefaction; LSeI in and around Bhuj Geomatics in Earthquake Mitigation Ramanuj Banerjee, Devendra Kumar, K. K. Mohanty and Shailesh Nayak ESHD/MWRG-RESA, Space Applications Centre (ISRO), Ahmedabad

13 13 PRE-SEISMIC PHASE URBAN VULNERABILITY The determination of risks asks also for other socioeconomic information (demographics, building stock characterization) and political issues (building regulations, level of enforcement, etc ).

14 14 PRE-SEISMIC PHASE URBAN VULNERABILITY Most of these parameters can be mapped with the use of SPOT panchromatic, and/or VHR data. Life-lines and urban vulnerability requires VHR data, able to map accurately at the building scale.

15 15 PRE-SEISMIC PHASE URBAN VULNERABILITY In urban areas permanent scatter, a variation of INSAR techniques (Ferreti et al., 1999) is now currently used map ground strain and stress accumulation even in dense urban areas.

16 16 POST-SEISMIC PHASE One of the key points for emergency managers is the availability of damage information within hours after the event. Mostly, evaluations must rely on models of damage assessment, based on territory (e.g. building stock, infrastructure, utilities), some of them also influencing seismic behaviour (e.g. depth to bedrock, soil type). The incorporation of non-local relief teams fosters the need to make quickly available cartographically accurate georeferenced maps. Also, insurers need to map risk and damage to assess their liability and validate claims.

17 17 POST-SEISMIC PHASE SURFACE CHANGES DETECTION The availability of pre and post-event RS imagery gives us the chance to compute fault rupture (and associated surface deformation), co-seismic deformation and even liquefaction effects gave the first sounded result of the use of SPOT imagery for the detection of surface effects related with earthquakes

18 18 POST-SEISMIC PHASE SURFACE CHANGES DETECTION ELASTIC MEDIA ELASTIC MEDIA

19 19 POST-SEISMIC PHASE SURFACE CHANGES DETECTION Using SPOT1 satellite images acquired approximately one month after the 1992 Landers earthquake, JPL captured the spatial details of terrain movements along fault breaks associated with the earthquake that were virtually undetectable by any other means

20 20 POST-SEISMIC PHASE SURFACE CHANGES DETECTION When we are most interested in quantitative surface changes than the SAR imagery, and particularly the DInSAR techniques are particularly relevant as they assure enough vertical accuracy to give us the possibility to detect very small changes (2-3 mm) in elevation over areas as large as 10,000 km2 of the Earth s (Massonnet et al., 1993).

21 21 POST-SEISMIC PHASE SURFACE CHANGES DETECTION Parmanent Scatterers J M MIRANDA UNIVERSITY OF LISBON

22 22 POST-SEISMIC PHASE SURFACE CHANGES DETECTION J M MIRANDA UNIVERSITY OF LISBON

23 23 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS Conventionally, damage extent is made by field teams that, in the aftermath of the events, map the consequences in terms of victims, building and infrastructure damage. The time needed for this task is clearly incompatible with the time available to take decisions on rescue.

24 24 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS Classification of damage to masonry buildings (EMS 1998) and typical pre- and post event QuickBird images for Grades 3, 4 and 5 houses (Yazaki and Matsuoto, 2006)

25 25 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS Visual classification of damage to masonry buildings (EMS 1998) for Bam 2003 earthquake, based on QuickBird imagery (modified from Yazaki and Matsuoto, 2006)

26 26 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS J M MIRANDA UNIVERSITY OF LISBON

27 27 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS J M MIRANDA UNIVERSITY OF LISBON

28 28 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS If we have access to pre- and post- event VHR images urban damage can be visually evaluated with great accuracy.

29 29 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS A systematic assessment of damage requires usually the use of damage scales

30 30 POST-SEISMIC PHASE POST-EVENT DAMAGE ESTIMATIONS The case of Sumatra Tsunami

31 31 EARLY-WARNING Kulikov and Shirshov use Jason data to discuss the importance of dispersion effects in deep water, only possible to identify due to the availability of satellite RS data. These observations are critical for the fine tuning of tsunami propagation models. Kulikov E, Shirshov P Dispersion of the Sumatra Tsunami Waves in the Indian Ocean detected by satellite altimetry Institute of Oceanology, Russian Academy of Sciences, Moscow

32 32 EARLY-WARNING The design of an operational warning system is so technical feasible, but requires a constellation of satellites to assure almost continuous monitoring of the earth surface with enough coverage to detect tsunami waves during the propagation phase.

33 33 FORECASTING Several claims have been made on the possibility to use RS data to detect precursors of seismic activity, even if none of the precursors has been conclusively demonstrated. It is known for a long time that seismic and magnetic activity have some kind of correlation. RS measurements of ionospheric precursors of earthquakes have been claimed by Serebryakova et al., (1992) and Liu et al., (2000).

34 34 FORECASTING J M MIRANDA UNIVERSITY OF LISBON

35 35 FORECASTING J M MIRANDA UNIVERSITY OF LISBON

36 36 FORECASTING J M MIRANDA UNIVERSITY OF LISBON

37 37 FORECASTING Thermal surveys are another candidate tool, based on the thermal IR information available in several satellite sensors. According to Tronin, (2000) NOAA/AVHRR-series satellite thermal images (STI) show the presence of positive anomalies (of the order of 2-3 C) at night-time, associated with large linear structures and fault systems.

38 38 FORECASTING J M MIRANDA UNIVERSITY OF LISBON

39 Thanks J M MIRANDA UNIVERSITY OF LISBON