Päivi Mäntyniemi

A new probabilistic seismic hazard analysis for the Vrancea (Romania) Seismogenic Zone

In this paper we apply a probabilistic methodology to map specific seismic hazard induced by the Vrancea Seismogenic Zone, which represents the uttermost earthquake danger to Romania as well as its surroundings. The procedure is especially suitable for the estimation of seismic hazard at an individual site, and seismic hazard maps can be created by applying it repeatedly to grid points covering larger areas. It allows the use of earthquake catalogues with incompletely reported historical and complete instrumental parts. When applying themethodology, special attention was given to the effect of hypocentral depth and the variation of attenuation according to azimuth. Hazard maps specifying a 10% chance of exceedance of the given peak ground acceleration value for an exposure time of 50 years were prepared for three different characteristic depths of earthquakes in the Vrancea area. These maps represent a new realistic contribution to the mitigation of the earthquake risk caused by the Vrancea Seismogenic Zone in terms of: (1) input data (consistent, reliable, and the most complete earthquake catalogue), (2) appropriate and specific attenuation relationships (considering both azimuthal and depth effects); and (3) a new and versatile methodology.

Estimate of earthquake hazard in the Vrancea (Romania) region

AbstractA maximum likelihood method is used to estimate the earthquake hazard parameters maximum magnitudeMmax, annual activity rate λ, and theb value of the Gutenberg-Richter equation in the Vrancea (Romania) region. The applied procedure permits the use of mixed catalogs with incomplete historical as well as complete instrumental parts, the consideration of variable detection thresholds, and the incorporation of earthquake magnitude uncertainty.Our imput data, comprises 105 historical earthquakes which occurred between 984 and 1934, and a complete data file containing 1067 earthquakes which occurred during the period 1935–30 August, 1986. The complete part was divided into four subcatalogs according to different thresholds of completeness. Only subcrustal events were considered, and dependent events were removed.The obtained

Uncertain historical earthquakes and seismic hazard: theoretical and practical considerations

\hat b

Seismic hazard in Fennoscandia: A regionalized study

value (=0.65) is at the lower range of the previously reported results, but it appears concurrent with conceptual and observational facts. The same concerns inferred value of

Earthquake scenarios: a practical way to handle alternative solutions to historical earthquakes and to increase the transparency of seismic hazard assessment

\hat M

The exceptional earthquakes in kaliningrad district, russia on september 21, 2004

max = 7.8 and activity rate