First surface temperatures survey
in Lake Abhe geothermal prospect
Kayad Moussa*a, Mohamed Jalludina
aCentre
d’Etude et de Recherche de Djibouti, (CERD)
P.O. Box: 486, Djibouti, REPUBLIC OF DJIBOUTI
Key word: Geothermal Resources, Geothermal Exploration, Natural Heat Flow, Conduction,
Convection, Heat loss
Abstract
The Lake Abhe geothermal prospect is located in South-Western part of the Republic of Djibouti. The
geological setting is controlled by the stratoid basalt outcrops affected by the main tectonic trends,
E-W and NW-SE, delineating high plateaus and plains. It is one of the thirteen potentials geothermal
fields identified in Djibouti. The Lake Abhe prospect is characterized with several surface
hydrothermal manifestations such as fumaroles, hot springs, altered zones, hot soils and numerous
massive travertine constructions aligned upon the main faults trend. These hydrothermal
manifestations results from the heat losses coming from the sub-surface geothermal reservoir by
two major mechanisms: conduction and convection. The purpose of the study is to evaluate the
distribution of the natural heat loss from the lake Abhe geothermal prospect in support to order
earth science methods to achieve the objectives of the prefeasibility study. A surface temperature
survey was conducted with 48 measurements at 0.5 m and 1 meter deep covering an area of 40 km².
Preliminary processing of the temperature survey data first reveals significant correspondences
between heat losses zones and surface hydrothermal manifestations. It is also in good agreement
with the anomalies recognized by the MT and the gravimetric surveys. As a consequence involving
the temperature survey among the comparative analysis of the different surface study methods is a
complementary approach to elaborate the conceptual model of the geothermal reservoir and to
contribute for well siting.