PROJECT RESIS II A new evaluation of Seismic Hazard for the Central America Region in the frame of the RESIS II Project.

Transcription

1 PROJECT RESIS II A new evaluation of Seismic for the Central America Region in the frame of the RESIS II Project. Mª Belén Benito, Wilfredo Rojas, Alvaro Climent, Enrique Molina, Griselda Marroquin, EmilioTalavera, José Jorge Escobar, Eduardo Camacho, Conrad Lindholm

2 Introduction Introduction This hazard analysis was developed for the whole Central America region in 28 Participation of seismologist from all the CA Countries Use of updated information of seismological and strong motion Data Banks New for three seismic sources: Crustal events, subduction interplate and inslab. Comparison and selection of strong motion models using actual and local data for each seismic source.

3 Introduction Group of work

4 contex Noth American Caribe system faults: Chixoy- Polochic -Motagua Subduction zone Coco s Caribe plates Earthquakes with high magnitude and epicenters offshore Local faults aligned with the volcanic chain Earthquakes with moderate magnitude, surface depth and epicenters near of population centers. More damaging earth.

5 PSHA ( Probabilistisc Seismic Assessment) Logic tree with a node for consider ing the uncertainty inherent to attenuation model Node 2 Node Zonification Atenuación Deaggregation: Determinaction of couple (M, R) with highest contribution to seismic hazard with a fixed return period. Definition of control earthquakes for RP=, and 2 years. branches R (km) Set of results Guatemala. PGA, PR años a) b 22 3 m ± s %Prob.2E-4.E-4 8.E- 6.E- 4.E- 2.E-.E R (

6 Regional Zonification (national detail) Crustal zones surface seismicity, h < 2 km Subduction interplate Intermediate seismicity 2 < h < 6 km Subduction inslab Depth seismicity, h > 6 km

7 Seismic Seismotectoni c >= 3. Earthquakes since 22 until Dec. 2 >= 3. Process carried out: Depuration: Standarization to Filtering of fore and aftershocks Completedness analysis :

8 Log(N) Log(N) Log(N) Log(N) Log(N) Log(N) Seismic parameters - Gutenberg-Richter models Zonas Corticales Costa Rica Zonas Corticales Honduras y Nicaragua C C2 C3 C4-P C C6 C C9 N N2 N3-4 N2-C N3 N4 N6-N N8 N9- H2 H3-N Zonas Corticales Guatemala Zonas Corticales Panamá y El Salvador G G2-S2 G3 G4 G-S-H G6 G G8 P2 P3 P4 P P6 P P8-C8 S S3 S4-N Crustal Inslab Zonas de Subducción Interfase Csi Csi2 Gsi9 Nsi Nsi6 Psi Psi9 Ssi Interface Zonas de Subducción Intraplaca Csp4 Csp Csp6 Gsp Nsp Psp Ssp M w M w

9 Distribution of b- values Values b between and.3 pre-arc zones, tensional efforts values b between. and.9 in volcanic chain, distensive regime. Values b between.6 and in interface inslab, normal ruptures, b between.6 and.

10 Attenuation Identification of the suitable GM models model Youngs et al. (99) (YOUN9) Atkinson y Boore 23 (AYB3) Garcia et al. (2) (GAR) Cepeda et al.(24) (CEP4) Climent et al. 994 (CLI94) Zhao et al. (26) (ZH6) Spudich et al. (999) (SEA99) Schmidt et al. (99) (SCH9) Data Base Mundial Mundial México El Salvador América Central and México Japón Mundial Component used (PGA, Sa) Media geométrica Las dos horizontals (Aleatoria) Media cuadrática Aleatoria Media geométrica Mayor de las horizontales Media geométrica Media geométrica Mayor de las horizontales sources Interplaca Intraplaca Interplaca Intraplaca Dist. (km) M w, , - 8,3 Intraplaca 4-4,2,4 Intraplaca Corteza Superficial Interplaca Corteza superficial Interplaca Intraplaca Corteza superficial 4 -, 8,3,,2-4 4, - 8, -3, 8,2 Corteza superficial -,,2 Corteza superficial 6-2 3,,6

11 Residuos Residuos Residuos Residuos Calibration of models with local data ( ID-2-43) Residual analysis (r = Ln GM* - Ln GM) Youngs et al., 99 Atkinson y Boore, Distancia (km) Distancia (km) 3 Climent et al., Zhao et al., Distancia (km) Distancia (km)

12 PGA (g) PGA (g) PGA (g) Selected attenuation models : Crustal, interface, inslab. Zhao et al., 26 Climent et al., 994. Youngs et al., PGA Distancia (km) PGA Distancia (km) Zhao et al., 26 Youngs et al., 99 M w. M w 6. M w... Distancia (km) Crustal: Climent et al (994) Zhao et al, (26) Subduction interface: Youngs et al (99 ) Subduction inslab: Youngs et al Zhao et al (26)

13 Estimation Software CRISIS 2 (Ordaz et al, 2) Estimation in a network with points separated. º longitude and latitude in terms of PGA and SA for T=.,.2,., y 2 s Logic tree with a node for attenuation models Every branch is a combination of models: crustal, + interface + inslab Seismic maps for PR=, and 2 years In the capitals of the 6 CA countrires: curves UHS Deaggregation for target motions given by PGA, SA (.2) and SA (s) ---- control eartquakes

14 maps PR= years PGA max =6 gal Panama Fracture gal in volcanic chain SA (.2) max =3 gal South Guatemala SA () max =3 gal Costal zones

15 Maps RP= years PGA max = gal Panama Fracture, South Guatemala and volcanic chain SA (.2) max =6 gal Panama Fracture, South Guatemala and volcanic chain SA () max =4 gal Panama Fracture, South Guatemala and volcanic chain

16 HAZARD MAPS PR=2 years PGA max = 8 gal South Guatemala SA (.2) max = 2 gal South Guatemala SA () max = gal South Guatemala

17 Probabilidad Anual Excedencia Seismic hazard curves in the capitals Probabilidad Anual Excedencia Probabilidad Anual Excedencia Probabilidad Anual Excedencia Probabilidad Anual Excedencia Probabilidad Anual Excedencia GUATEMALA PGA SA(.s),E+2,E+ SAN SALVADOR SA(.2s),E+,E+2 SA(.s) PGA,E-,E+ SA(.s) SA(.s),E+ SA(2.s),E-2 SA(.2s) MANAGUA,E-,E+2 SA(.s),E-3 SA(.s),E-2,E-4,E+ SA(2.s),E-,E-3,E+,E-4,E-,E- Aceleración (gal) SAN JOSÉ,E-2,E+2,E-3 Aceleración,E+ (gal) PGA SA(.s) SA(.2s) SA(.s) SA(.s) SA(2.s) PGA SA(.s),E-4,E+ SA(.2s) TEGUCIGALPA,E-,E-,E+2 SA(.s) SA(.s),E-2 PGA,E+ SA(2.s) Aceleración (gal2) SA(.s),E-3,E+ SA(.2s),E-4,E- SA(.s),E- SA(.s),E-2 PANAMÁ SA(2.s) Aceleración,E+2 (gal) PGA,E-3 SA(.s),E+,E-4 SA(.2s),E+ SA(.s),E- SA(.s),E- SA(2.s) Aceleración (gal),e-2,e-3,e-4,e- Aceleración (gal)

18 Deaggregation R (km) Guatemala. PGA, PR años a) b) a) %Prob San Salvador. PGA,.2E-4 PR años E b) Guatemala. SA(.s), P %Prob 8.E- 6 9.E-.2 Managua. PGA, 6.E- 6.2PR 8.E- años a). b 6..E E E %Prob 2.E-.E E-4 4.E E+.4E-4. 3.E- 22. R (km) E-.2E E-.E E+ 8.E- 6.2 R (km) 22. R (km) E E- Guatemala. 8 SA(.s), P 2.E E+ R (km) R San Salvador. PGA, PR 2 años San Salv c) %Prob 3 4. d). 3.E E-. %Prob Guatemala. PGA, PR 2 años c) d) San Sal

19 Deaggregation a) San José. PGA, PR años b) San José. SA( %Prob T R (km) 22 3 a) Tegucigalpa. PGA, PR años.2e-4.2 b) 4. R (km) 22.E-4. %Prob 8.E- 6.E- Panamá. PGA, PR 6.2 años 6.E- 6.E- 4.E- 2.E-.E E c) d) San José. PGA, PR 2 3años 4. R (km) Tegucigalpa. PGA, 3 PR %Prob 2 años.2.e- 4.E- 3.E- 2.E-.E-.E %Prob 6 6.E E E E E-. R (km) 6..E-. San José. SA( 8.2.E+. R R (km) 4. a) b) c) 8d) 4.. T

20 CONCLUSIONS (I) For all return periods the highest values of PGA are predicted in Panamá Fracture zone, South Guatemala and certain zones of volcanic chain. Maximun PGA : RP = years, gal RP= years, gal RP = 2 years, 8 gal Similar morphology for maps of SA (.2 s) with maximun values RP = años, 3 gal RP= años, 6 gal R P= 2 años, 2 gal Maps of SA ( s) with maximun in coastal zones, due to the highest influence of the subduction events.

21 CONCLUSIONS (II): Specific results in the capitals: Highest hazard in Guatemala City and San Salvador, followed by San José and Managua and minor hazard in Panamá and Tegucigalpa. Deaggregation Control earthquakes are identified in the capitals : ( Target motion given by PGA and RP= y) In general, a near shock is dominant (M 6-6.; R km) identified with a volcanic chain event. Exception of Tegucigalpa where a far event is dominant (M 6., R 2 km) and Panamá, where neither clear event is found. In Guatemala City, San Salvador and Managua a second longdistance earthquake M ~ is found with important contribution, identified with a subduction event.

22 How to get the project results: CA country reports (in spanish) Regional CA report (in spaniish) Seismic hazard maps in ArcGis Format Book: Seismic in Central America (in spanish) Benito and Torres (eds), 2 Entimema Press, Madrid A new evaluation of Seismic for the Central America Region in the frame of the RESIS II Project. The 4 th World Conference on Earthquake Engineering October 2-, 28, Beijing, China

23 THANKS FOR YOUR ATTENTION!!!