Major floods in Nairobi have been in news this week (at least locally, global media does not pay much attention – just imagine the amount of coverage if this happened in the western world). Having floods in Nairobi is nothing new, but these are mostly restricted to slum areas on riverbanks receiving no government attention whatsoever. But flooding of this scale in the Kenyan capital is beyond people’s memory. Other than Nairobi, big floods have occurred this year in various parts of Kenya, notably in Narok town.
Days after the devastating earthquake in Nepal, The Economist has published an article on big earthquakes in the last 20 years and their geographical occurrence, triggering us to write on the issue with an African perspective. Why and where earthquakes happen is controlled by plate tectonics. Seismically most active areas are convergent margins, i.e. where continental and or oceanic plates collide with each other. This includes almost the entire eastern coast of the Americas, a trail from Japan to New Zealand via Indonesia and Fiji, and a belt from Turkey to China, including Himalayas where the recent Nepal earthquake occurred.