O Sistema de Rift Africano: Algumas considerações

Abstract

When we look to the world map of heat flow, we see in Africa regions with low heat flow values ( around 40 mW m-2) separated by regions where the heat flow values are higher ( 60 to 80 mW m-2).When we look to the geological map we can see, in the eastern zone of the map, one of the most extensive rifts on the Earth’s surface, extending from Jordan in south western Asia to Mozambique in south eastern Africa. The system is 6,400 Km long and averages 48 to 64 km wide, and consists of two branches. The main branch, the Eastern Rift Valley extends along the entire length of the system, from Jordan River and Dead Sea to Kenya and continues Southward through Mozambique Plain to the coast of the Indian Ocean near Beira. The western branch of the system extends northwards from the northern end of lake Nyasa in a great arc that includes several lakes. Most of these lakes are deep with their floors below sea level. The rift has an age of 30 million years. This work represents an attempt to study this region using thermal data including heat flow data, thermal springs location and water temperature, seismicity data and temperature data collected at the bottom of the holes during drilling works.