The Seismotectonic Map of Africa

Abstract

We present the Seismotectonic Map of Africa based on a geological, geophysical and geodetic database including instrumental seismicity and re-appraisal of large historical events, and harmonization and homogenization of earthquake parameters in the catalogues. Although establishing the seismotectonic framework of the African continent is a difficult task, several previous and ongoing projects provide a wealth of data and outstanding results. The database of large and moderate earthquakes in different geological domains includes the coseismic and Quaternary faulting that reveals the complex nature of the active tectonics in Africa. The map benefits from previous works on local and regional seismotectonic maps that needed to be integrated with the lithospheric and upper mantle structures, seismic anisotropy tomography and gravity anomaly, into a continental framework. The synthesis of earthquake and volcanic studies obtained from the analysis of late Quaternary faulting and geodetic data will serve as a basis for hazard calculations and the reduction of seismic risks. The map will be useful for the seismic hazard assessment and earthquake risk mitigation for significant infrastructures and their socioeconomic implications in Africa. The constant population increase and infrastructure growth in the continent that exacerbate earthquake risk justify the necessity of continuously updating this map. The database and related map are prepared in the framework of the IGC Project-601 "Seismotectonics and Seismic Hazards in Africa" of UNESCO-IUGS, funded by the Swedish International Development Agency and UNESCO-Nairobi for a period of 4 years (2011-2014, now extended to 2016).

Post-rift stratigraphic architectures along the African margin of the Equatorial Atlantic: Part I the influence of extension obliquity

“…Onshore, post-early Paleogene offsets and seismicity on faults connected to transforms also indicate very late post-rift reactivations (e.g. Bellion et al, 1984;Bellion and Robineau, 1986;Meghraoui et al, 2016).…”

Rifting of the Kalahari Craton Through Botswana? New Seismic Evidence

“…It is located within the Kaapvaal Craton, 120 km southeast of the main event, at the junction of the WSW‐ENE trending Zoetfontein Fault with a southern branch and a northwesterly branch extending to central Botswana. The area is known to be seismically active, but mostly with magnitudes smaller than 5 (Meghraoui & the IGCP‐601 Working Group, 2016). Several small events in our catalog can be associated to these known faults in the Zoetfontein Fault region of Kaapvaal Craton (Figure 2).…”

Geothermal Renewable Energy Prospects of The African Continent Using GIS

“…(Figure 3) Faults and fractures are important in controlling geothermal potential since hydrothermal uids migrate most effectively through faults (Hanano, 2000). Faults on the geological map of Africa (Thiéblemont et al, 2016;Meghraoui et al, 2016) were collected and digitized (Figure 3). Much of the geothermal activity in Africa is concentrated in the east of the continent around the EARS, where continental rifting is associated with geothermal systems with magmatic and volcanic heat sources.…”