Probabilistic Assessments of the Seismic Hazard in Northern Armenia (Spitak Region)

Abstract

The Spitak (Armenia) earthquake of December 7, 1988, (M=6.9) revealed the necessity to revise the assessments of seismic hazard obtained in the past. We used recently developed method for quantitative probabilistic assessment of seismic shaking to resolve the problem. The assessments of probable intensity of shaking in terms of MSK - 64 intensity scale showed that for this region the intensity with return period T=1000 years must be taken as MSK IX instead of MSK VII and MSK VIII assigned to Armenia by the building code. Probable Fourier and response spectra of ground acceleration have been estimated also, and may be used for design and construction of new building and structures in this region.