NATIONAL UNIVERSITY OF ENGINEERING LIMA-PERU Faculty of Civil Engineering SCENARIO EARTHQUES IN PERU Zenón AGUILAR, Dr. Eng. Nelson E. Pulido H. National Research Institute for Earth Science and Disaster Prevention (NIED), Japan Collaborators:Hernando Tavera (IGP, Perú), Zenón Aguilar (UNI, Perú), Diana Calderón (UNI, Perú), Mohamed Chlieh (U. Nice-Sophia, France), Toru Sekiguchi (U. Chiba), Shoichi Nakai (U. Chiba), and Fumio Yamazaki (U. Chiba) JAPAN PERU CENTER FOR EARTHQUAKES ENGINEERING RESEARCH AND DISASTER MITIGATION - CISMID Contents Historical earthquakes in Central Andes, Perú Estimation of earthquake scenarios for Central Andes Construction of broadband source models for strong motion simulations Strong motion simulations for Lima from the scenario earthquakes
1 3 5 7 9 11 13 15 17 19 21 81 IX 50 40 30 20 10 IX X ESCALA 1:2'000,000 0 50 100 VIII X IX X 71 69 67 1 3 5 7 9 11 13 15 17 19 21 HISTORICAL EARTHQUAKES IN PERU 1746 265 years Nazca ridge 1868 143 years Adapted from Okal et al (2006) 1940 05 24 Huacho, M8.2 1942 08 24 San Juan, M8.0 1966 10 17 Barranca, M8.1 1974 10 03 Lima, M8.1 2001 06 23 Atico, M8.4 2007 08 15 Pisco, M8.0 Sladen et al. (2010) 79 75 77 73 71 69 67 COLOMBIA ECUADOR TUMBES PIURA CAJAMARCA AMAZONAS LAMBAYEQUE LA LIBERTAD SAN MARTIN LORETO BRASIL MAMUN SEISMIC INTENSITIES OBSERVED IN PERU. ANCASH OCEANO PACIFICO HUANUCO PASCO UCAYALI Alva Hurtado et al (1984) JUNIN LIMA MADRE DE DIOS HUANCAVELICA CUZCO IC A AYACUCHO APURIMAC PUNO BOLIVIA UNIVERSIDAD NACIONAL DE INGENIERIA FACULTAD DE INGENIERIA CIVIL CISMID MAPA N 1 MAPA DE DISTRIBUCION DE MAMAS INTENSIDADES SISMICAS OBSERVADAS AREQUIPA MOQUEGUA TACNA Ref. JORGE ALVA HURTADO et al (1974) LEYENDA CHILE X IX VIII VII V IV VALOR EXTREMO DE CARACTER LOCAL 81 79 77 75 73
HISTORICAL SEISMIC ACTIVITY IN PERU (Tavera et al) GPS campaigns in Peru-Northern Chile 87 surveyed sites (19932003) from Lat. 11ºS to Lat. 24ºS. Including measurements from ocean bottom GPS offshore Lima Kendrick et al. (2001), Chlieh et al. (2004), Gagnon et al. (2005)
Slip deficit rate for Peru and Northern Chile and scenario earthquake for Central Peru (Chlieh et al. 2011) Slip deficit since 1746 (265 years) Maximum slip is 15 m Magnitude Mw~8.9, neglecting the 20 century earthquake sequence (Pulido et al. 2011) C(x) * vo S(x): slip, t : elapsed time S(x)=C(x) * vo * t Hypocenter locations scenarios Lima Pisc o
Array microtremors measurements in Lima, Peru, and installation of a strong motion network [SATREPS project] Small Arrays Large Arrays New Seismometers Dispersion curve and estimated Vs profile Observation sites in Lima Velocity models obtained from microtremors arrays in Lima and their 1D transfer functions (Calderón et al. 2012)
Strong motion simulation method [Pulido et al. 2004, 2007, 2011] A ij ( f ) = R pij ( θ, φ, f ) M 0 S ( f, Δσ i ) G ( f 3 4πρβ R ij ) e πfr ij Q ( f ) β P( Acceleration Fourier Spectra at the i subfault and j station f, f max ) Simulated PGA at Lima for all slips models Peak values for every slip model is averaged for all rupture starts
Simulated PGV at Lima for all slips models Peak values for every slip model is averaged for all rupture starts Simulated PGA and PGV at Lima including site effects Average values for slip No.5 and all rupture starts
Simulated Acceleration and Velocity response spectra at Lima including site effects (h=0.05) Sa, T=0.3 s Sv, T=1.0 s Sv, T=1.5 s Average values for slip No.5 and all rupture starts Simulated PGA at Lima for all rupture starts Slip model No. 5
Simulated PGV at Lima for all rupture starts Slip model No. 5 Simulated strong ground motion at PQR, Lima Slip scenario No.5 and 7 and starting point of the rupture at the southern edge of the fault PQR PQR
Conclusive remarks Central Andes region in Peru has the potential of generating an earthquake with magnitude of 8.9, and a source area of approximately 500 by 165 km 2 Our results show average PGA and PGV values as large as 1000 cm/s 2 and 80 cm/s in Lima Our simulated PGA and PGV in Lima are 2~3 times larger than the values observed in Parque de la Reserva, central Lima, during the 1974 and 1966, M8 earthquakes.