Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

New Considerations about Chile’s Seismic Hazard

Sergio. Barrientos

Scientific Director

Servicio Sismológico, Universidad de Chile

sbarrien@dgf.uchile.cl

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Page 3

Energy Released by Earthquakes

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Data from Engdahl and Villaseñor (2003).

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Wadati-Benioff Zone

Barazangi and Isacks (1976)

Engdhal and Villaseñor (2003)

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

1922

Beck et al, 1998

Page 7

ThrustSismos Prisma

Outerise

Intraplaca prof. Intermedia

Corticales

Seismic Sources in Chile

fosa

costa

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Barrientos (1997)

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Chillan, 1939Beck et al., (1998)

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Fault size:Length: 1000 kmWidth: variable 120-150 kmAverage displ: 17 mMaximum displ: 35-40 mRecurrence: At least 500-yr

Page 12

Pre-1960 Events (Cisternas et al., 2005)

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Dec, 1949, Magallanes

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Illapel, 1997

Outer rise1939, 1950, 2005

2004Trench

Trench

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Mag h (km) p.a. Reference

Santiago 1945 7.1 71 0.13g Lepe y Torre (1950)

Las Melosas 1958 6.9 5 -10 0.05g Piderit y Lomnitz (1960)

La Ligua 1965 7.1 72 0.19g Malgrange et al. (1981)

La Ligua 1971 7.5 30 0.17g Malgrange et al. (1981)

M=7.5 every 110 yr

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

ES(1)

ES(2)

eM

E SR

20

Tarapacá, 2005

January 7, 2003 Mw 5.9

Tarapacá, 2005

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

03.1

83.0

)60(

3.71

R

ea

sM

91.30006.0)log(74.338.1)( rrMrI S

Attenuation relationships

Saragoni et al.

Barrientos (1981)

Montessus de Ballore Conference Santiago, Chile, Nov. 2006

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Martin (1991)

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Brief Update of the Earthquakes inTocopilla Mw= 7.7 andAysén Mw= 6.2

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Graber (1997)

Page 23

Coseismic Displacement, Antofagasta30 Julio 1995 Mw=8.0

Melbourne et al.., 2002De Louis et al., 1997

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Coseismic Displacement, Antofagasta30 Julio 1995 Mw=8.0

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Coseismic Displacement, Tocopilla14 Nov 2007 Mw=7.7

Observatory Earthquake Readiness Workshop , La Serena Dec. 2007

Page 27

J. Cembrano (2007)

AYSÉN Marco Tectónico

Evolución de la Sismicidad

Page 28

21 Apr 06 M= 6.2

5.2

4.4

4.8

5.14.5

5.6

5.5

Page 29

Caída de Rocas, Deslizamientos y Tsunami21 Abril 2007

Page 30

Generacion de Tsunami

Page 31

Punta Tortuga

Page 32

Epicenters and Focal Mechanisms

Observatories Earthquake Readiness Workshop , La Serena Dec. 2007

Thanks a lot for yourattention

VI Congreso Chileno de Geotecnia Valparaíso, Nov. 2007

Murdie (1993)

VI Congreso Chileno de Geotecnia Valparaíso, Nov. 2007

VI Congreso Chileno de Geotecnia Valparaíso, Nov. 2007

VI Congreso Chileno de Geotecnia Valparaíso, Nov. 2007