Research Topic 1. Assessing the Current State of Practice in Seismic Hazard Analysis in South America (SA)

Participants

Methodology

The first step was the consolidation of existing seismic hazard knowledge in the region. Seismic hazard studies (at national and regional level) were appraised for consistency and overall characteristics and many of them implemented into the OpenQuake-engine. Local experts helped to guide this process during a meeting held at the Colombian Geological Survey (CGS), Bogota, in July 2014 by sharing their knowledge and experiences of hazard modelling in their regions and identifying key issues and limitations.

The main outcomes of these discussions can be summarised as follows:

  • The level of documentation available rarely allows an accurate reproduction of the procedure used for the construction of the models.
  • Area sources are without question the commonest typology used to model seismicity occurrence without relevant distinctions between the different tectonic contexts (e.g. active shallow crust, subduction interface and in-slab).
  • The quantity and quality of information needed for the parameterization of shallow fault sources in terms of geometry and seismicity occurrence discouraged their use within PSHA in the region.
  • The selection of ground motion prediction equations (GMPEs) is scarcely documented, and the criteria used for choosing GMPEs unclear.
  • A limited treatment of epistemic uncertainty.

Main Results achieved within RT1

A harmonized compilation for some of the recent national hazard models (see Table and Figures below) was created. This compilation demonstrates the need for a harmonized modelling of hazard at a continental level and was used as a starting point for the construction of the new hazard model for the South America continent.

List of PSHA models considered and/or implemented

The next Table and Figures summarise the models analysed and their main characteristics.

Region Year Authors/Institution Source typology Logic tree Availability Additional info
Contact person Area/Grid/Fault ERF/GMPE
Bolivia 2013 OSC / E. Minaya YES/NO/YES* NO/NO NO Unpublished, see details in OSC
Brazil 2015 PSHAB /M. Assumpcao YES/YES/NO YES/YES NO See details in PSHAB
Chile 2014 UC / R. Boroscheck YES/NO/NO YES/YES NO See details in Núñez et al. (2015)
Colombia 2010 SGC / M. Arcila YES/NO/NO NO/YES YES Unpublished, more information in SGC
Ecuador 2011 IGEPN / H. Yepes YES/NO/YES NO/YES YES Developed in collaboration with IRD and GEM
Peru 2015 IGP / H. Tavera YES/NO/NO NO/NO NO Unpublished
Venezuela 2015 FUNVISIS/ H. Rendon YES/NO/NO Under preparation by FUNVISIS
Continent 2010 USGS / M. Petersen YES/YES/YES YES/YES YES Preliminary model developed by USGS
Continent 1999 GSHAP / YES/YES/NO NO/NO NO Two projects: PILOTO and PAIGH
  • OSC: Observatorio San Calixto, La Paz, Bolivia
  • PSHAB: Study group in Probabilistic Seismic Hazard Analysis in Brazil, several universities, Brazil
  • UC: University of Chile, Santiago de Chile, Chile
  • SGC: Colombian Geological Survey, Bogota, Colombia
  • IGEPN: Instituto Geofísico de la Escuela Politécnica Nacional, Quito, Ecuador.
  • IRD: Institut de Recherche pour le Développement, France
  • IGP: Instituto Geofísico de Perú, Lima, Perú
  • FUNVISIS: Fundación Venezolana de Investigaciones Sismológicas, Caracas, Venezuela
  • USGS: U.S. Geological Survey
  • GSHAP: Global Seismic Hazard Assessment Program
  • GEM: GEM Foundation, Pavia, Italy
  • PILOTO: Dimaté et al. (1999)
  • PAIGH: Tanner and Shepherd (1997)

National PSHA models

National PSHA models considered within RT1: left) shallow crust zones, right) subduction zones [interface and in-slab]. For Chile and Brazil the main and most updated bibliographic references are cited (see Table above).

References

Dimate, C., L. Drake, H. Yepez, L. Ocola, H. Rendon, G. Grünthal, and D. Giardini (1999). Seismic hazard assessment in the Northern Andes (PILOTO project). Annali di Geofisica, 42(6): 1039–1055.Paper

Núñez, I., Boroschek R., Comte, D., Contreras, V. (2015). “Nuevo Peligro Sísmico para Chile”. Student: Ignacio Nuñez., Proceeding at XI Congreso Chileno de Sismologia e Ingenieria Sismica ACHISINA 2015, Santiago de Chile, 18-20 de Marzo, Chile. In Spanish.Prooceding

Petersen, M., S. Harmsen, K. Haller, C. Mueller, N. Luco, G. Hayes, J. Dewey, K. Rukstales (2010). Preliminary Seismic Hazard Model for South America. In the Proceeding of the International Conference “Homenaje a Alberto Giesecke Matto”.

Tanner, J.G. and J.B. Shepherd (1997): Seismic hazard in Latin America and the Caribbean, Volume I: Project catalog and seismic hazard maps, IRDC, Ottawa, 143 p.Report

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  • Last modified: 2016/07/20 16:25
  • by Julio Garcia