Speaker
Description
Probabilistic Seismic Hazard Assessments (PSHA) have not been conducted in large parts of Sub-Saharan Africa (SSA), due to incomplete earthquake catalogues, sparse seismic networks, etc; raising concerns on needed information for planning and disaster risk management. This study aims to bridge this research gap using modern techniques. Updated catalogue from Local Networks, significant data from the Comprehensive Nuclear-Test-Ban Treaty Organization's National Data Centers, International Seismological Centre, and publications, spanning 1615-2024 with threshold and maximum moment magnitudes (Mw) of 4.0 and 6.8 formed the data set. The catalogue declustered and harmonized to Mw was used with available geological data to delineate area source zones and compute earthquake hazard parameters. Four ground motion prediction equations (GMPEs) for tectonically similar regions to SSA were implemented using logic tree formalism in the calculation, with all equations weighted equally. Within the 1-1000-year period considered, the computed Gutenberg-Richter b-value, activity rates, and regional maximum possible magnitudes ranged from 0.69-1.0, 1.6-2.1, and 5.2-7.2, respectively. Peak Ground Accelerations ranged 0.02g-0.2g for a 10% chance of exceedance in 50 years, and seismic hazard maps for 0.1s, 0.2.s, 0.3s, 0.5s, and 0.15s periods were produced. The results are expected to significantly contribute to planning in the vast region.
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