Seismic risk is on the rise in sub-Saharan Africa, due to urbanization and population growth. However, short-term crises and other pressing issues are higher on the agenda of most decision-makers, and seismic risk is often underestimated. What most people do not realize is that several mega-cities in the region are located near active rifts, faults and tectonic elements (such as Nairobi and Accra1) and its people and buildings would suffer greatly from an earthquake.
That justifies a need to include earthquake risk management in decision-making in urban planning, decisions on finance and priorities at various scales in our region.
At the moment we do not yet have enough information to build a case for that however. We still need to work hard to get more insight into seismic hazard and risk, though it is especially information on risk (exposure and vulnerability) that we lack. Information that can be used for risk scenarios, to quantify possible damage and loss in different areas, as input for managers and decision-makers.
On the earthquake hazard side, we are advancing. We, a group of seismologists from sub-Saharan Africa, are undertaking a joint effort to share knowledge, harmonize catalogues, produce more realistic projections of seismic hazard than currently available, benefitting from GEM’s support.
Since 2009, when GEM took off, we saw the opportunity to benefit from knowledge and tools developed within the framework of GEM, and organized several meetings. This summer, however, activity increased, when about 25-30 hazard experts from the region got to spend a week in CapeTown for meetings, discussions and 2 days of technology transfer and joint learning.
Last week, four months after the Cape Town meeting, GEM supported representatives from all four sub-regions (West, Central, East and Southern Africa) to come to Italy to the GEM Secretariat. We spent a week working with Marco Pagani and Graeme Weatherill in taking the first steps towards creating an integrated model for seismic hazard in our region.
It was good to sit together and see the fruit of true collaboration in the region. Now we start to understand the issues we need to tackle together, such as those involved in homogenizing our different catalogues (duplicates, errors, etc.). In Pavia we started to put together all sources of catalogues as well as gather information on sources of earthquakes in the regions and develop a very rough seismotectonic zonation map. With that map we can now move forward.
At the moment, unfortunately, we have no structural funds to push the effort forward quickly, but with the support of GEM, our own organizations and networks such as AfricaArray and ESARSWAG, we are progressing step-by-step and hope to soon share more results of our joint work. We will leverage as much as possible on existing meetings and gatherings in the region to sit down and discuss steps forward, hopefully involving more and more of our colleagues. We also want to scan more publications on relevant topics, such as geology and seismotectonic information so as to keep on incorporating new knowledge.
We see and understand that sharing data is not easy, especially because for many it is our only ‘bread’, but we also experience now that if we don’t share, we will not progress. Faults and quakes cross borders so we must do it together. The advanced open-source tools that are being developed by GEM’s Model Facility and partners will enable us to advance seismic hazard assessment more and more. For example in a few months’ time the first version of our homogenized earthquake catalogue will become available.
And then.. we need to link up with the engineers and organizations that possess knowledge on Africa’s building stock, so that we can move from hazard to risk! The tools being developed in GEM also in that area can be of great help,, such as the (IDCT) field tools that engineers can use to assess buildings (both before and after earthquakes) and build datasets. GEM's Global Building Taxonomy a classification scheme for all buildings worldwide, is also a good framework for understanding the vulnerability of our buildings and we need to make sure all different types of buildings are represented in it.
Hereby we call out to all engineers, experts and organizations whose work relates to buildings and building types, (vulnerable) population and housing in sub-Saharan Africa. Contact us, let us know what you are working on and then let’s work together on building a strongercase for investing in seismic risk mitigation. Because even moderate shaking could lead do disastrous events in our region, especially where people are moving out of rural houses built from natural materials, into poorly constructed concrete and brick buildings. So its time for action!
We look forward to hear from all of you. Thanks, and.. to be continued.
Ofonime Akpan, Paulina Amponsah, Atalay Ayele, Bekoa Ateba, Vunganai Midzi and Thifhelimbilu Mulabisana, on behalf of all those working on GEM sub-Saharan Africa
1: See for example Neglected vulnerabilities in a rapidly urbanizing city: reflections on earthquake risks in Accra and Earthquake-disaster preparedness: the case of Accra