← Back to Sessions

WITHDRAWN Seismic Hazard Studies in West Africa Using Integrated Techniques for Planning and Development of Critical Facilities

Description: 

WITHDRAWN No in-depth seismic hazard study for West Africa (WA) has ever been conducted because of incomplete earthquake catalogues, which negatively affects the planning and development of critical infrastructure by construction industries and disaster risk management by the relevant agencies. This bridges the knowledge gap by updating the current earthquake catalogue for WA. The seismotectonic setting of WA is considered stable continental crust despite several recorded earthquakes occurring in the region, the largest being the 22 June 1939 earthquake of magnitude M6.8 with epicentre in Ghana. However, WA has also been classified as a region of shallow crustal seismicity. Therefore, we investigated both research schools of thought using integrated techniques, compared their results using three different ground-motion models (GMMs), and combined to produce each hazard map using logic tree formalism with equal weights. The region was divided into five seismic source zones to compute the earthquake recurrence parameters, with the same parameters computed for the entire WA region. The computed Gutenberg–Richter b-value, activity rates λ, and regional maximum possible magnitudes m_max for the five zones ranged from 0.84 to 1.0, 0.3–2.1, and 5.2–7.0, respectively. The calculated b-value, λ, and m_max for the entire WA were 0.77, 4.1, and 7.2, respectively. The estimated b-value of 0.77 falls within the generally accepted range for tectonic seismicity. The seismic hazard predicted by GMMs for stable continental areas was higher than that predicted for shallow crustal seismicity in WA, confirming that the region is characterised by stable continental crust. The highest hazard levels were observed in Ghana, Guinea, etc, ranging 0.02-0.03 g. Results from this study will help the construction industries and policymakers, especially in policy making with respect to designing and developing critical facilities in the region, whose damage from seismic hazards could cause enormous losses.

Session: Advancing Seismic Hazard and Risk Assessment through Multi-Disciplinary Approaches [Poster]

Type: Poster

Date: 4/15/2026

Presentation Time: 08:00 AM (local time)

Presenting Author: Umar A. Kadiri

Student Presenter: No

Invited Presentation: 

Poster Number: 44

Authors