MARsite New directions in Seismic Hazard Assessment through Focused - PowerPoint PPT Presentation

MARsite New directions in Seismic Hazard Assessment through Focused Earth Observation in the Marmara Supersite WP6 : Earthquake Induced Landslide Hazard in Marmara P. Bigarré, INERIS

A major natural geohazard : seismic landsliding M 6.7 Northridge, Thrust, 19 km deep > 11.000 Harp & Jibson, 1995 1994, California > 24 km 2 M 7.6 Chi-chi , 1999, 100 km N-S fault > 20.000 Lin et al, 2000 > 150 km 2 Taiwan segment M 8 Wenchuan, 2008, Thrust, 20 km deep > 56 000 Dai et al, 2011 > 40 000 km 2 M 7 Haiti, 2010 Thrust, 12 km deep, > 1 000 USGS > 10 000 km 2

The Sea of Marmara The Sea of Marmara is prone to various geohazards, such as earthquakes, landslides, tsunamogenic submarine landslides (Gorur, 2009) : • In Turkey total loss caused by landslides in terms of affected buildings constitutes 27% of the entire loss from all natural hazards (Duman, 2005), especially in the seismically active NAF Zone (Gokceoglu, 2005) • The 17 August 1999 Mw 7.4 Kocaeli earthquake caused extensive landslides, subsidences and liquefaction-induced ground deformations along the coast of Izmit Bay (Cetin, 2004) • Numerous tsunami occurrences are historically related to the earthquakes in the segments of the WNAF (Altinok, 2000) • Major submarine mass wasting - landslides have been observed and mapped from high resolution surveys (Gazioglu , 2005) • Tsunami effects were observed and measured during the 1999 post-event surveys in several places along both the northern and the southern coasts of the Izmit bay (Tinti & al, 2006)

On shore : the Westward Metropolitan aera of Istanbul

Off shore : Entrance of the Gulf of Izmit

WP6 - Task1.a & 2.b: CNR ISMAR – ITU contributions (Luca Gasperini, Sinan Ozeren) and CEREGE

WP6 - Task1.b: TUBITAK Contribution (Semih Ergintav) INTERACTIONS BETWEEN LANDSLIDES AND ACTIVE FAULTING Based on field geological observations, Seismic lines shown on the map provide a link Duman et al. (2004, between the seismic sections and the structural 2005a,b) have argued that the causes of features in this figure. Note the correlation between the landslides are slope the locations of the heavy landslides instability, shallow groundwater level, and the fault zone (Ergintav, 2011). lithology and liquefaction.

WP6 – Task2.b: IU - INERIS Contribution (Oguz Ozel, Stella Coccia) Investigation of site effects with new microtremor campaign NEW STUDY The area shown in the map will be investigated in detail by microtremor measurements and other shallow geophysical measurements. PREVIOUS STUDY Study Area (Picozzi et al., 2009): Western part of Istanbul: single station noise measurements at free field sites (dots), IERRS stations (rhombus, name of stations with earthquake recordings is indicated), and 2D array measurements (squares). The map is taken from TUBITAK Final Project Report,No: 5077101, 2008

WP6 – Task2.b: IFSTTAR Contribution (Luca LENTI) & Third Party “La Sapienza” Dynamic numerical models of interaction between seismic waves and landslides Validity of the attenuation law of Sabetta and Pugliese (1987),with related standard errors (dashed line), for the equivalent signals obtained by LEMA_DES for each distance class. Physical and mechanical parameters used for the FDM numerical modelling: den — density; ν — Poisson's ratio; G0 — elastic shear modulus; D0 — initial damping; Vs — Evaluation of permanent deformations on “first time” landslide slopes shear wave and/or pre-existing sliding processes by considering coupled scenarios velocity; ϕ — internal friction angle; c — cohesion; ten — tensile cut-off; dil — dilation angle; g — shear strain; G/G0 of geological and hydrogeological conditions by the means of FD — shear modulus ratio; D/D0 — damping ratio. nonlinear codes. from Lenti & Martino (2012)

WP6 – Tasks 1.b and 2.b: IU - INERIS Contribution Seismic induced landslides susceptibility and mapping Hydrology Site effects Landslide Shaking susceptibility Predictive Displacement Dn Seismic landsilde susceptibility

WP6 – Task2.b: IU - INERIS Contribution (Auxane Cherkaoui) Seismic induced landslides susceptibility and mapping A detailed procedure has been published by Westen (ICT). Kaynia et al (2011) have published on near to real time mapping of seismic landslides

WP6 - Task1.b: INGV Contribution (Marco Moro) Kinematics of Deep-seated Gravitational Slope Deformations from DInSAR time-series Descending LoS velocity map (values in mmyr−1). Legend: 1) Upper limit of DGSD; 2) Quaternary active fault; 3) Major trench; 4) Rock avalanche source area. Three-dimensional view and simplified geological cross-section for the Colle Cerese DGSD. Vertical scale is exaggerated ~2 × . Legend: 1) Carbonate platform and ramp formations (Dogger [middle Jurassic] – lower Miocene); 2) Lacustrine deposits (Pleistocene); 3) Talus material, residual karst and fluvio-lacustrine deposits (Holocene); 4) Normal fault.

WP6 – Task1.b: UNIPV Contribution (Paolo Gamba) PMVE Spatial PMVE

WP6 – Partners and main tasks 3 5 6 8 9 13 17 18 Task / subtask TUBITAK INGV IU ITU CNR (ISMAR- INERIS UNIPV IFSTTAR IREA) Semih Ergintav Marco Moro Oguz Ozel Sinan Ozeren Luca Gasperini Pascal Bigarre Paolo Gamba Luca Lenti Task 1 Investigations of local instability areas - onshore and offshore – and developing of advanced susceptibility mapping Task 1a In-depth survey Off-shore landslide of large and Tsunami hazard potential slides Task 1b Interaction Kinematics of Landslide On-shore landslides between Deep seated hazard scale Advanced landslides and Gravitational based on GIS structural slope hyperspectral geology deformations image data Task 2 Ground motion data, local seismic site effects and dynamic numerical modelling Task 2a Numerical Off-shore landslide modeling of and Tsunami hazard landslide generated tsunamis Task 2b Dynamic On-shore landslides Advanced Numerical Sites effects – GIS modeling of new micro- Selection of permanent tremor landslide pilot deformations campaign site of seismic slopes