An Earthquake Catalogue for El Salvador and Neighboring Central American Countries （1528-2009） and Its Implication in the Seismic Hazard Assessment

Merging all available databases, a comprehensive and updated earthquake catalogue for El Salvador and surrounding areas has been compiled, containing a total of 2,584 events for the period 1528-2009, covering the geographic window delimited by the coordinates 11.0°-16.5° N and 85.5°-92.0° W, focal depths of 0.0 to 304 km, and the moment magnitudes in the interval 5.0 〈 Mw 〈 8.1. Events in the catalogue are distributed into six seismogenic sources taking into consideration the tectonic regime affecting E1 Salvador, the interplay and complexities between shallow crustal, intraplate and interface subduction seismicity has been thoroughly investigated, primarily with the aim of developing detail criteria to delimit the seismogenic sources in order to perform a consistent seismic hazard assessment. A uniform hazard spectrum for San Salvador and seismic hazard maps and their uncertainty have been calculated for the horizontal component of ground motion for rock site conditions using zone and zone free methods. The references cited in the article constitute a comprehensive list of sources of information on the tectonics and seismicity of El Salvador and neighboring Central American countries.

GIS-based study of the evolution of the IGN's strong motion network of mainland Spain and the balearics

In some countries with seismicity,an adequate detection network is essential to assess seismic hazards.The Instituto Geografico Nacional(National Geographic Institute/IGN)of Spain manages a strong motion network distributed throughout the whole country and an earthquake detection network composed of velocity stations.This paper aims at studying the development of the strong motion network of the Spanish National Seismic Network(focusing on mainland Spain and the Balearics)in the last three decades.A Geographic Information System(GIS)has been implemented to integrate the attributes from the IGN’s database concerning the earthquake catalogue,seismograph and accelerometer networks,which enabled to analyse the data and map the distribution of detection equipments in the region.The irregularly distributed Spanish strong motion network was greatly expanded from 1990 to 2010.In the past decade,it developed at a slower rate,but more modern technology was implemented.

Probabilistic Seismic Hazard Assessment for Jamaica

A probabilistic seismic hazard analysis was performed to generate seismic hazard maps for Jamaica. The analysis was then conducted using a standard logic-tree approach that allowed systematically taking into account the model-based （i.e., epistemic） uncertainty and its influence on the computed ground motion parameters. Hazard computations have been performed using a grid of sites with a space of 0.05 degrees. Two different computation methodologies have been adopted： the standard approach based on the definition of appropriate seismogenic sources and the zone-free approach, which overcomes the ambiguities related with the definition of the seismic sources solely reflecting the characteristics of the earthquake catalogue. A comprehensive and updated earthquake catalogue for Jamaica has been compiled for the years 1551-2010 and new empirical relationships amongst magnitudes Mze-Ms and Mw-mb have been developed for the region. Uniform hazard spectra and their uncertainty have been calculated for the horizontal component of ground motion for rock site conditions and five return periods （95, 475, 975, 2,475 and 4,975 years） and spectral accelerations for 34 structural periods ranging from 0 to 3 s, and 5% of critical damping. The spectral accelerations have been calculated to allow the definition of seismic hazard in Jamaica according to the International Building Code 2012. The disaggregation analysis for Kingston Metropolitan Area suggests that the magnitude-distance pair that contributes most to the hazard corresponds to events with M 7.8 and M 7.0 in the Enriquillo Plantain Garden Fault and the Jamaican Faults at a distance of 28 km and 18 km for short and long period structures respectively corresponding to 2,475 years return period. However, for long period structures, a substantial contribution is found for a M 8.2 at a distance of 198 km in the Oriente Fault Zone.

Principles and Methods of Determining Epicenter Reference Place Name

Determining an epicenter reference place name (herein after to be referred as "DERPN") is a basic task,but is very important for standardizing the compilation of earthquake catalogues.However,there has been little studies on DERPN.This paper summarizes the development and issues surrounding DERPN and puts forward principles and methods of DERPN.

Life-Cycle and Seismic Fragility Assessment of Code-Conforming Reinforced Concrete and Steel Structures in Bucharest, Romania

In this article, the fragility of reinforced concrete and steel structures in Bucharest, a city of high seismic hazard, designed using the recent building codes in Romania, is assessed. A total of 24 reinforced concrete and steel structures with heights varying from five stories to 13 stories were analyzed. Their seismic fragility was evaluated using two procedures from the literature. In the first procedure(SPO2 FRAG), the fragility was derived based on the pushover curves using the SPO2 IDA algorithm, while in the second procedure(FRACAS), the fragility was derived from nonlinear time-history analyses. The analyzed structures were designed for three levels of peak ground accelerations, corresponding to mean return periods of 100,225, and 475 years. Subsequently, the damage assessment of the analyzed structures was performed using ground motions generated from a Monte-Carlo simulated earthquake catalogue for the Vrancea intermediate-depth seismic source. The damage degrees that were estimated using the SPO2 FRAG approach are higher than those estimated using the FRACAS approach. The life-cycle analysis of the structures shows that a further increase of the design peak ground acceleration for Bucharest is feasible from an economic point of view using the SPO2 FRAG results.However, based on the FRACAS results, the opposite conclusion can be drawn. Finally, generic lognormal fragility functions are proposed as a function of building height and structural system.