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Participants IPGP: 

When in 1968, plate tectonics became the only sensible hypothesis, Djibouti was quickly identified as a place where an oceanic ridge can be observed "on shore" as in Iceland, and therefore an excellent place to verify (and quantify different aspects of) this hypothesis.


Very rapidly large measurement campaigns have been conducted : deep seismic sounding profiles in 1971, first geodetic network in 1972, gravity and aeromagnetic surveys.


In 1973, following a strong seismic crisis that was largely felt in Djibouti, a geophysical Observatory was set up on the Arta mountain. After djiboutian  independence in 1977, the Observatory has been jointly managed by IPGP and the Republic of Djibouti. This Observatory has been the starting point for many scientific expeditions in the region. For the last 40 years, it has been monitoring the rich seismicity of the Gulf of Aden, the Red Sea, the Gulf of Tadjoura, the volcanic seismicity of the Asal Rift, zones of active distension in the Afar triangle and its borders : around 1000 to 2000 events per year.


Most of French researchers in Geodesy have started their career in Djibouti. The repetition of the measurement of the geodetic network after the Adoukoba rifting episode, allowed to measure the spreading of an active rift for the first time. Metric displacements were observed. This was also the topic of the first real life. inverse problem, studied by Albert Tarantola. A wide range of instruments have been used for this purpose: from the theodolite to space instruments (Doris), GPS in 1987, radar interferometry, laser measurements.