lisbon, may 24 th and 25 th 2007, lessloss dissemination workshop simulating earthquake scenarios in...

Lisbon, May 24Lisbon, May 24thth and 25 and 25thth 2007, LESSLOSS Dissemination workshop 2007, LESSLOSS Dissemination workshop

Simulating Earthquake Scenarios in the Simulating Earthquake Scenarios in the

European Project LESSLOSS: the case of the European Project LESSLOSS: the case of the

Metropolitan Area of Lisbon (MAL)Metropolitan Area of Lisbon (MAL)

INGV-LNEC TeamINGV-LNEC Team

ZonnoZonno G.G.11, , Carvalho A.Carvalho A.22,, Franceschina G.Franceschina G.11,, Campos Costa A. Campos Costa A.22, Coelho E., Coelho E.22, , Akinci A.Akinci A.11, Cultrera G., Cultrera G.11, Pacor F., Pacor F.11, Pessina V., Pessina V.11 and Cocco M. and Cocco M.11

11)) INGVINGV - Istituto Nazionale di Geofisica e Vulcanologia, - Istituto Nazionale di Geofisica e Vulcanologia, Italy Italy 22)) LNECLNEC - Laboratório Nacional de Engenharia Civil - Laboratório Nacional de Engenharia Civil, Portugal, Portugal

6th Framework Programme Priority 1.1.6.3 – Global Change and Ecosystems

The LESSLOSS ProjectRisk Mitigation for Earthquakes and Landslide


Within the framework of theWithin the framework of the

LESSLOSSLESSLOSS – Risk Mitigation for Earthquakes and Landslides – Risk Mitigation for Earthquakes and Landslides

ground motion scenarios are computed ground motion scenarios are computed on the basis of the most on the basis of the most probable 50 and 500 years Return Period event defined by specific probable 50 and 500 years Return Period event defined by specific location and magnitude for three urban areas: location and magnitude for three urban areas: LisbonLisbon (Portugal), (Portugal), Thessaloniki Thessaloniki (Greece) and (Greece) and Istanbul Istanbul (Turkey)(Turkey)

Seismic Seismic Hazard Map of Hazard Map of the European-the European-Mediterranean Mediterranean region,region, in terms in terms of peak ground of peak ground acceleration at a acceleration at a 10% probability 10% probability of exceedance of exceedance in 50 yearsin 50 years

[from Jiménez, [from Jiménez, Giardini and Giardini and Gruenthal, 2003].Gruenthal, 2003].

SIMULATING EARTHQUAKE SCENARIOS IN THE EUROPEAN PROJECT LESSOSS

Lisbon Lisbon ThessalonikiThessalonikiIstanbulIstanbul


This contribution This contribution

““Simulating Earthquake Scenarios in the European Project Simulating Earthquake Scenarios in the European Project LESSLOSS: the case of the Metropolitan Area of Lisbon (MAL)”LESSLOSS: the case of the Metropolitan Area of Lisbon (MAL)” isis a part of Sub-Project 10 of the LESSLOSS Project, a part of Sub-Project 10 of the LESSLOSS Project, “Disaster scenarios predictions and loss modeling for “Disaster scenarios predictions and loss modeling for urban areas”;urban areas”;

The overall aim of SP 10 is:The overall aim of SP 10 is:

““to create a methodology, based on state-of-the-art loss to create a methodology, based on state-of-the-art loss modeling software, to provide strong, quantified statements modeling software, to provide strong, quantified statements about the benefits and costs of a range of possible mitigation about the benefits and costs of a range of possible mitigation actions, to support decision-making by city and regional actions, to support decision-making by city and regional authorities for seismic risk mitigation strategies”authorities for seismic risk mitigation strategies”

The SP 10 “Disaster scenarios The SP 10 “Disaster scenarios predictions and loss modeling for urban predictions and loss modeling for urban areas”areas”


Estimation of ground shaking using Deterministic Seismic Hazard Analysis (DSHA)

Earthquake scenario = for a given site, the ground shaking level (in terms of PGA, PGV, SA and time series) is computed with a specific finite-fault method and with given hypothesis regarding the reference earthquake..

1.1. Finite-fault effectsFinite-fault effects and and directivitydirectivity are important because are important because of the relative nearness of seismic source;of the relative nearness of seismic source;

2.2. The The urban urban level of losses scenario ask for level of losses scenario ask for high resolution high resolution of ground motion inputof ground motion input to match with the complexity of to match with the complexity of geotechnical characterization, vulnerability data and geotechnical characterization, vulnerability data and exposure factors;exposure factors;

3.3. When applied to When applied to critical structurescritical structures DSHA provides a DSHA provides a straightforward framework for evaluating the straightforward framework for evaluating the worst-caseworst-case ground motions.ground motions.


INPUT TOOLS OUTPUT

Historical and seismotectonical considerations

Probabilistic mapsPSHA

Deaggregation analysis

Choice of seismic source

DSMRSSIM FINSIM

Ground motion at bedrock

Properties of the source and the crustal medium

Surface shaking mapGeotechnical

dataLNECloss

System

A general framework for the HAZARD A general framework for the HAZARD STUDY procedureSTUDY procedure in the case of Lisbonin the case of Lisbon


Analysis of the active faults for the Analysis of the active faults for the selection ofselection of the reference earthquakes the reference earthquakes

OOFFFFSSH H O O R R EE

S S O O U U R R C C E E SS

Active faults in Active faults in SW IberiaSW Iberia ( (modified modified from from Zitellini et al., 2005Zitellini et al., 2005), ), considerable as probable sources for considerable as probable sources for the 1755 earthquake. the 1755 earthquake. MPFMPF – Marquês – Marquês de Pombal Fault, de Pombal Fault, PSFPSF – Pereira de – Pereira de Sousa Fault, Sousa Fault, HSFHSF – Horseshoe Fault, – Horseshoe Fault, GBFGBF – Guadalquivir Bank Faults. Red – Guadalquivir Bank Faults. Red star represents location of 1969 star represents location of 1969 earthquake.earthquake.

ININLLAANND D

SSOOUURRCCEESS

Neotectonic of the Tagus Valley Neotectonic of the Tagus Valley Region (Region (modified from Vilanova modified from Vilanova and Fonseca, 2004and Fonseca, 2004). ). VFVF- Vila - Vila Franca Fault, Franca Fault, ArRArR- Arrábida range, - Arrábida range, AFAF-Alcochete fault. Double dot -Alcochete fault. Double dot represents location of 1909, no represents location of 1909, no bold represents location of the bold represents location of the 1531, Benavente earthquakes.1531, Benavente earthquakes.


DE-AGGREGATION of PSHA for the Metropolian Area of Lisbon

The seismic action scenarios were defined on the basis of the obtained modal values derived from the last recent study

(Sousa, 2006) on 3D de-

aggregation analyses in M

and (X, Y) (magnitude and coordinates of bin source)


Reference earthquakes for given Return Period Reference earthquakes for given Return Period using the de-aggregation of the PSHAusing the de-aggregation of the PSHA

The The reference earthquakesreference earthquakes with with Return Period of 50 and 500Return Period of 50 and 500 years years have been used to evaluate scenarios as input have been used to evaluate scenarios as input for for loss modelingloss modeling in in the Metropolitan Area of Lisbonthe Metropolitan Area of Lisbon

The reference earthquakes with The reference earthquakes with Return Period of 200 yearsReturn Period of 200 years have have been used to evaluate and compare scenariosbeen used to evaluate and compare scenarios with the different with the different methods and to do the methods and to do the treatment of the uncertaintytreatment of the uncertainty


Metropolitan Area of Lisbon Metropolitan Area of Lisbon andand the the selected Reference Earthquakes (for selected Reference Earthquakes (for different RP)different RP)

Metropolitan Area of LisbonMetropolitan Area of Lisbon

M

PTF M

7.9

MPTF M

7.9

LTVF M 4.4LTVF M 4.4LTVF M 5.7LTVF M 5.7

MPTF M

7.6

MPTF M

7.6

Test pointsTest points

Parishes of MALParishes of MAL


Simulating Earthquake Scenarios using Simulating Earthquake Scenarios using Finite-Fault ModelFinite-Fault Model

AA

GeneralGeneral

SchemeScheme

ToTo

EvaluatEvaluatee

GroundGround

MotionMotion

At TheAt The

Site Site

Using a Using a

Finite Finite

FaultFault


Simulating Earthquake Scenarios using Simulating Earthquake Scenarios using Finite-Fault ModelFinite-Fault Model

The Finite-Fault Model ParametersThe Finite-Fault Model Parameters

Finite-fault simulations require informationFinite-fault simulations require information onon the the fault-plane fault-plane geometrygeometry ( (length, width, strike and diplength, width, strike and dip), the ), the source parameterssource parameters ((seismic moment, slip distribution, stress drop, nucleation point, seismic moment, slip distribution, stress drop, nucleation point, rupture velocity, etcrupture velocity, etc.), the .), the crustal propertiescrustal properties of the region of the region ((geometrical spreading coefficient, quality factor, etcgeometrical spreading coefficient, quality factor, etc.) and the .) and the site-site-specific soil response.specific soil response.

A dataset of digital A dataset of digital acceleration acceleration

records obtained records obtained from the from the

Portuguese Portuguese accelerometer accelerometer

network at hard-network at hard-rock sites was rock sites was employed to employed to

calibrate specific calibrate specific simulation simulation parametersparameters


Portugese digital network to calibrate Portugese digital network to calibrate the crustal properties of the regionthe crustal properties of the region

Portugese digital network Portugese digital network (above) and epicenter (above) and epicenter

locations of some locations of some recorded earthquakes recorded earthquakes

(right)(right)


THE NUMERICAL APPROACHES THE NUMERICAL APPROACHES USED IN THE EUROPEAN PROJECT LESSLOSS USED IN THE EUROPEAN PROJECT LESSLOSS

In the European Project LESSLOSS SP 10 we evaluate shaking In the European Project LESSLOSS SP 10 we evaluate shaking scenarios using the following Finite-fault approaches:scenarios using the following Finite-fault approaches:

1.1. Deterministic-Stochastic simulation Method, Deterministic-Stochastic simulation Method, DSM DSM (Pacor et al., 2005) (used for three cities);(Pacor et al., 2005) (used for three cities);

2.2. Non-stationary stochastic Finite fault simulation Non-stationary stochastic Finite fault simulation Method, RSSIM Method, RSSIM (Carvalho et al., 2004) (used only for MAL).(Carvalho et al., 2004) (used only for MAL).

FURTHERMOREFURTHERMOREto compare and to calibrate the methods we use also:to compare and to calibrate the methods we use also:

FINSIMFINSIM (Beresnev and Atkinson, 1998 (Beresnev and Atkinson, 1998), ), a stochastic finite-fault a stochastic finite-fault methodmethod and and EXSIMEXSIM ( (Motazedian and Atkinson,2005Motazedian and Atkinson,2005): a ): a stochastic finite-fault method with “the dynamic corner stochastic finite-fault method with “the dynamic corner frequency” option.frequency” option.


DSM : Deterministic Stochastic DSM : Deterministic Stochastic Method Method (Pacor et al., 2005)(Pacor et al., 2005)

km

N

P1

P2

P1 : directive site

P2: anti-directive site

The methods DSM, The methods DSM, FINSIM and RSSIM are FINSIM and RSSIM are

all Finite-Fault all Finite-Fault approaches that are approaches that are

based on a modification based on a modification of the Point-Source-of the Point-Source-Stochastic-MethodStochastic-Method of of

Boore [2003] Boore [2003]

The DSM computes The DSM computes two horizontal two horizontal components of components of

motion and motion and reproduces very reproduces very well the directive well the directive

effectseffects


RSSIM : RSSIM : Non-stationary stochastic finite Non-stationary stochastic finite fault simulation method fault simulation method (Carvalho et al., 2004)(Carvalho et al., 2004)

The RSSIM method is customized for engineering applications it works inside the LNECLoss system. It is a spectral approach.

A new stochastic procedure, A new stochastic procedure, after after Serra Bilé and Caldeira, 1998Serra Bilé and Caldeira, 1998

The The earthquake earthquake

scenarios for scenarios for each parish each parish

are defined by are defined by the the

computation computation of the Power of the Power

Spectra Spectra Density Density Function Function (PSDF) of (PSDF) of surface surface

acceleration acceleration with due with due

consideration consideration of local site of local site

effects.effects.


TREATMENT OF UNCERTAINTYTREATMENT OF UNCERTAINTY

In order to evaluate the variability depending on the In order to evaluate the variability depending on the uncertainties of input parameters a sensitivity analysis is uncertainties of input parameters a sensitivity analysis is done varying the following input parametersdone varying the following input parameters::

1.1. Different Different velocities of rupturevelocities of rupture ( (VrVr))

2.2. Different Different nnucleation ucleation ppointsoints: bilateral : bilateral propagation (propagation (NP = 2NP = 2) and two others ) and two others as unilateral direction with the as unilateral direction with the nucleation point at the bottom corners nucleation point at the bottom corners ((NP =1NP =1 and and NP = 3NP = 3))

3.3. homogeneous homogeneous slip distribution model for slip distribution model for the the Lower Tagus Valley Fault (LTVF)Lower Tagus Valley Fault (LTVF) M 5.7M 5.7 with Return Period (RP) 200 years with Return Period (RP) 200 years

4.4. Different different slip distribution Different different slip distribution model for the model for the Marques Pombal Thrust Marques Pombal Thrust Fault (MPTF)Fault (MPTF) M 7.6M 7.6 with Return Period with Return Period (RP) 200 years(RP) 200 years

LTVFLTVF M 5.7M 5.7


TREATMENT OF UNCERTAINTY. DSM method:TREATMENT OF UNCERTAINTY. DSM method:changing rupture nucleation pointschanging rupture nucleation points

at the BEDROCKat the BEDROCK

Lower Tagus Valley Lower Tagus Valley Fault (LTVF) Fault (LTVF) M 5.7M 5.7 (RP 200 yr)(RP 200 yr)


TREATMENT OF UNCERTAINTY. DSM method:TREATMENT OF UNCERTAINTY. DSM method:changing rupture velocity and nucleation pointschanging rupture velocity and nucleation points


S021S021

S137S137

S250S250

S268S268

Vr = 2.7 km/sec; Vr = 2.7 km/sec;

NP = 2 NP = 2 (bilateral case)(bilateral case)

S174S174

Lower Tagus Valley Fault (LTVF) Lower Tagus Valley Fault (LTVF) M 5.7M 5.7 (RP 200 yr) (RP 200 yr)


TREATMENT OF UNCERTAINTY. DSM method:TREATMENT OF UNCERTAINTY. DSM method:changing rupture velocity and nucleation pointschanging rupture velocity and nucleation points


S021S021

S137S137

S250S250

Vr = 2.7 km/sec; Vr = 2.7 km/sec; NP = 1 NP = 1 (directive case)(directive case)

S174S174

S268S268

Lower Tagus Valley Fault (LTVF) Lower Tagus Valley Fault (LTVF) M 5.7M 5.7 (RP 200 yr) (RP 200 yr)


TREATMENT OF UNCERTAINTY. TREATMENT OF UNCERTAINTY. DSM method:DSM method:changing rupture velocity and nucleation pointschanging rupture velocity and nucleation points

S137S137

S250S250

S174S174


Vr = 2.7 km/sec; Vr = 2.7 km/sec; NP = 3 NP = 3 (directive case)(directive case)

S268S268

S021S021

S250S250

S174S174S137S137

Lower Tagus Valley Fault (LTVF) Lower Tagus Valley Fault (LTVF) M 5.7M 5.7 (RP 200 yr)(RP 200 yr)


SLIP DISTRIBUTIONS and SLIP DISTRIBUTIONS and NUCLEATION POINTSNUCLEATION POINTS (Gaussian distribution centered on nucleation points)

TREATMENT OF UNCERTAINTY: TREATMENT OF UNCERTAINTY: changing slip model and nucleation pointschanging slip model and nucleation points

22

11

33

11

16 DIFFERENT MODELS16 DIFFERENT MODELS

NUCLEATION POINTSNUCLEATION POINTS

SLIP 1SLIP 1

SLIP 2SLIP 2

SLIP 3SLIP 3

SLIP SLIP RANDOMRANDOM

33

33

33

33

11

11

11

11

22

22

22

33

RR

RR

RR

RR


TREATMENT OF UNCERTAINTY. FINSIM method: TREATMENT OF UNCERTAINTY. FINSIM method: changing slip model and nucleation points changing slip model and nucleation points

Shaking at the BEDROCKShaking at the BEDROCK

16 DIFFERENT MODELS16 DIFFERENT MODELS

NUCLEATION POINTSNUCLEATION POINTS

SLIP 1SLIP 1

SLIP 2SLIP 2

SLIP 3SLIP 3

SLIP SLIP RANDOMRANDOM

33

33

33

33

11

11

11

11

22

22

22

33

RR

RR

RR

RR

S174S174

MMPPTF TF M M 7.6 RP 7.6 RP 200 200 yryr


TREATMENT OF UNCERTAINTY. FINSIM method: changing slip model and nucleation points

Inferred variability could be

treated in a statistical way

but for the loss modeling

in MAL

“the worst-case”

was adopted with purpose of generating precautionary scenarios only

The yellow bars are the total frequency histogram of 480 times series The yellow bars are the total frequency histogram of 480 times series (16 models x 30 trials) at the site S174 in case of the MPTF (16 models x 30 trials) at the site S174 in case of the MPTF M 7.6M 7.6


The shaking at the surface was evaluated The shaking at the surface was evaluated using the LNECloss systemusing the LNECloss system

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

0 200 400

E

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

0 200 400

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

0 200 400

E

10 0 10 Kilometers

N

AAAABACADAEAFAGAHAIAJAKBCDEFGHIJKLMNOPQSTUVWXYZ

Soil Columns Units

The site effectsThe site effects are evaluated by means of an equivalent are evaluated by means of an equivalent stochastic non-linear one-dimensional ground response stochastic non-linear one-dimensional ground response analysis of stratified soil profile units properly designed for the analysis of stratified soil profile units properly designed for the Metropolitan Area of LisbonMetropolitan Area of Lisbon


PGA scenario (Return Period 50 years) used to PGA scenario (Return Period 50 years) used to evaluate loss modeling in MAL (Boomer evaluate loss modeling in MAL (Boomer attenuation law)attenuation law)

Lower Tagus Valley Fault (LTVF)Lower Tagus Valley Fault (LTVF) Mw 4.4Mw 4.4

at the BEDROCKat the BEDROCK at the SURFACEat the SURFACE


PGA scenario (Return Period 500 years) used to PGA scenario (Return Period 500 years) used to evaluate loss modeling in MAL (attenuation law evaluate loss modeling in MAL (attenuation law using RSSIM method)using RSSIM method)

Marques Pombal Thrust Fault (MPTF) Mw 7.9Marques Pombal Thrust Fault (MPTF) Mw 7.9

at the SURFACEat the SURFACEat the BEDROCKat the BEDROCK


1.1. In this study we simulate the ground motion shaking (at the In this study we simulate the ground motion shaking (at the bedrock and surface levels) for the Metropolitan Area of Lisbon bedrock and surface levels) for the Metropolitan Area of Lisbon (MAL) with two proposed scenarios: (MAL) with two proposed scenarios: Lower Tagus Valley FaultLower Tagus Valley Fault (LTVF) (LTVF) Mw 4.4Mw 4.4 (RP 50 years) and (RP 50 years) and Marques Pombal Thrust Marques Pombal Thrust FaultFault (MPTF) (MPTF) Mw 7.9Mw 7.9 (RP 500 years); (RP 500 years);

2.2. The ground motion shaking have been computed first at the The ground motion shaking have been computed first at the bedrock sites. To include the local site effects, available bedrock sites. To include the local site effects, available microzonation studies have been used to characterize the site microzonation studies have been used to characterize the site amplification. In the case of Lisbon, the characterization of local amplification. In the case of Lisbon, the characterization of local soil effects is taken into account, using the soil effects is taken into account, using the LNECloss systemLNECloss system, , computing the Power Spectra Density Function (PSDF) at the computing the Power Spectra Density Function (PSDF) at the surface level;surface level;

3.3. A treatment uncertainty was carried out for different A treatment uncertainty was carried out for different methodologies (methodologies (DSMDSM, , RSSIMRSSIM and and FINSIMFINSIM) and the variability of ) and the variability of ground motion was studied. The variability of ground motion was ground motion was studied. The variability of ground motion was inferred from a set of fault ruptures scenarios incorporating inferred from a set of fault ruptures scenarios incorporating different nucleation points, different ruptures velocities and slip different nucleation points, different ruptures velocities and slip distribution.distribution.

RESULTS and COMMENTSRESULTS and COMMENTS


RESULTS and COMMENTSRESULTS and COMMENTS

o Following the purposes of the SP10 we have worked with Following the purposes of the SP10 we have worked with existing methods and the GIS-based software as the existing methods and the GIS-based software as the LNECLoss systemLNECLoss system (Campos Costa et al., 2002) that (Campos Costa et al., 2002) that comprises several modules to perform seismic risk comprises several modules to perform seismic risk analyses. The only two used modules concerning this analyses. The only two used modules concerning this study are the study are the Bedrock Seismic InputBedrock Seismic Input and and Local Soil Effects Local Soil Effects evaluationevaluation

o An improvement of the An improvement of the LNECloss systemLNECloss system could be possible could be possible incorporating the new approaches and all knowledge on incorporating the new approaches and all knowledge on sensitivity studies gained during the European Project sensitivity studies gained during the European Project LESSLOSS. LESSLOSS.

lisbon, may 24 th and 25 th 2007, lessloss dissemination workshop simulating earthquake scenarios in...

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