Initiatives of Application of the Bakun-Wentworth's Method for the Estimation of Macroseismic Parameters in the Northern South America and the Caribbean Region
Abstract
The assessment of location, magnitude and uncertainties of great historical earthquakes is a key issue for understanding the seismic potential and PSHA of a region. In the last years independent techniques using only macrosesismic data points have been developed as, for example, the approach of Bakun and Wentworth (1997) or BW. This method has been largely applied in different tectonic contexts (Bindi et al., 2013), in different UE international projects and in estimations of location, magnitude and epistemic uncertainties (Bakun et al., 2011). We focus on some regional calibration initiatives in Northern South America and areas of the Caribbean Region. BW has been calibrated by Palme et al. (2005) and Choy et al. (2012) for earthquakes of the Mérida Andes and the Venezuela Central Regions. As well, BW calibrations have been proposed for the interandean Valley in Ecuador (Beauval et al., 2010), in the Hispaniola (Bakun et al, 2012) and for the northeastern Caribbean region (ten Brink et al., 2011). Preliminary BW calibration for the southeastern region of Cuba has been proposed by Gómez-Capera et al. (2012). Applications to historical earthquakes in Cuba have given encouraging results mainly for offshore events and are presented in the present study. We also present preliminary results for some earthquakes that have been recently studied in literature as for example the historical earthquakes of 1743 (Salcedo Hurtado and Gómez-Capera in press) and 1785 (Salcedo Hurtado and Castaño Castaño, 2011) which occurred close to Bogotá, BW method and intensity relationship of the literature were used. We present comparisons and sensibility analysis of the different relationships obtained in the region as well as uncertainty assessment. We also note that the magnitude parameter depends strongly on the regional calibration. Because of the availability of new macroseismic studies in Colombia (Servicio Geológico Colombiano y Universidad Nacional de Colombia, 2013; available online in http://agata.ingeominas.gov.co:9090/SismicidadHistórica/), Venezuela (http://sismicidad.ciens.ula.ve) and Caribbean Region, in the future it is expected to propose models for macroseismic intensity attenuations of regional character especially in Colombia and in Venezuela in the Cumaná region. This region has a rich earthquake history. In this topic of the regional calibration of intensity attenuation relationships, the situation is challenging because several historical and recent earthquakes in this region are attributed to subduction zones. It is therefore necessary to involve focal depth. This is still an open problem.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSM.S52A..05G
- Keywords:
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- 7209 SEISMOLOGY / Earthquake dynamics;
- 7212 SEISMOLOGY / Earthquake ground motions and engineering seismology