Seismic Hazard and Risk in the region
Earthquakes such as the one in Mozambique (M7, 2006) and Malawi (M6.2, 2009) are not uncommon on the sub-Saharan African continent. Seismic hazard analysis in the region faces several challenges; incomplete, inhomogeneous and uncertain catalogues, is sparse network coverage and poor knowledge of crustal structures and attenuation. Furthermore there is a lack of skilled technicians, seismologists and engineers. There is little collaboration between seismologists and engineers and the level of knowledge on damage and loss due to earthquakes is very low, also because there is hardly any information on the (value of) the building stock.
Building a regional programme
Contributors and participants in sub-Saharan Africa got together various times over the past years, to discuss the state-of-the-art in the region and the setup of a Regional Programme. The group is building its efforts on ongoing projects such as SeTMA, the ESARSWG active fault mapping project, the seismic hazard map of the Democratic Republic of Congo and the Seismotectonic map of South Africa, projects of ICSU ROA and regional fault mapping projects.
By splitting the region up into four: Wast, Central, Eest and South, the group divides tasks and takes steps in integrating data and knowledge.
Who are involved?
- Atalay Ayele is the Operational Manager in sub-Saharan Africa he is based in Addis Abbeba where he works at the University.He can be reached at atawon[at]yahoo.com
- Ray Durrheim, John Dumisani Hlatywayo, Gladys Kianji, Vunagai Midzi, Ofonime Akpan; they play coordinating roles
- In each of the sub-regions there are the following individuals:
West Africa: Ofonime Akpan, Paulina Amponsah, Carlien Bou-Chedid
Central Africa: Georges Mavonga Tuluku, Ateba Bekoa, Alain Pierre Tokam Kanga
East Africa: Atalay Ayele, Nada Ahmed, Richard Ferdinand, Gladys Kianji, Michael Msabi, Fred Tugume
South Africa: Ray Durrheim, John Dumisani Hlatywayo, Virgilio de Magelhaes, Hlompo Malephane, Brassnavy Mzunzu, Vunganai Midzi, Thifhelimbilu Faith Mulabisana, Tebogo Pule, Brian Zulu
First steps towards integrated hazard modelling
After the summer meetings, representatives of each region came to Pavia to work on homogenising their catalogues and in making the first steps towards building a model. It was not to merge the earthquake catalogues prepared by different group leaders, because of duplicates and other issues. There were other technical difficulties of having spatial gap around the equator which we are currently working on. We also noted that we still lack information for zoning sources and characterizing faults.
With all these difficulties we marched ahead and have chosen the region of the Horn of Africa as a pilot site to test the OpenQuake Engine and produce seismic hazard output. In the image below you can see the tentative area sources map that we developed for that region.