Seismic hazard evaluation for specific seismic regions of the world

Abstract

Seismic hazard is estimated for fifty of the most seismically active countries of the world using the technique of Gumbel's third asymptotic distribution of extreme values and hazard maps are produced. For this purpose a catalogue of 9700 earthquakes with magnitudes M ≥ 5.5 has been compiled and earthquakes in the time period 1898–1985 are examined here. An equal area grid point mesh, of about 5° latitude × 5° longitude, is chosen to represent the local seismicity. This cell size corresponds approximately to the area of Romania which is the smallest country examined. The results estimate the most probable maximum magnitude for a time period of 85 years, which exceeds magnitude 7 for all fifty of the cellular seismic regions, and the contour maps and tables show its spatial variation and rank the countries in terms of overall relative seismic hazard. The maps effectively produce a brief seismic hazard atlas.