Salahadin Ali Abdurahma

Abstract

The Tendaho geothermal field is located in the Afar triangle (Northern Afar) about 700km northeast of Addis Ababa within the Dupti cotton plantation. The Afar triangle is an area of active extensional tectonics and basaltic magmatism from which the Gulf of Aden, the Red Sea and the Ethiopian rift systems radiate. Normal faults and open fissures are the principal elements of the Afar tectonics. These phenomena are exhibited by lineaments of hot springs, warm springs and mud pools.

In the Tendaho Geothermal Field, three deep (1811m-2100m) and three shallow (466m-516m) exploratory wells were drilled, four of which (one deep and three shallow wells) were found to be potentially productive. These productive wells supply sufficient steam to produce about 3 MWe.

The main purpose of this work is to evaluate the different hypotheses given previously regarding the recharge of the Tendaho geothermal field.

In order to evaluate the given hypotheses, previous work and data was reviewed and water samples collected for chemical and isotope analysis with the aim of getting full information about the Tendaho geothermal system. After using different chemical and isotopic techniques, the following conclusions are given: both the chemical and the isotopic constituents of the waters of the Lakes District are different from the waters of Northern Afar and have no imprint of genetic relation with the waters of Northern Afar.