His major contribution to science has been to study how continents break apart by analysing the earthquake and volcanic activity of the Afar Triangle. He has researched many volcanoes in Ethiopia and Eritrea, including Corbetti, Mount Ayalu, Adwa (volcano), Erta Ale, Dabbahu Volcano, Dallol, and Nabro Volcano. He has conducted much of his research in collaboration with Kathryn Whaler and Ian Bastow.