Haraldur SigurdssonHaraldur Sigurdsson is emeritus professor at the Graduate School of Oceanography, University of Rhode Island in the United States of America. He has worked on volcanic processes and the geochemistry of volcanic rocks for over fifty years. His studie have in part been focused on the impact of volcanic activity on human populations, especially his work on Vesuvius in Italy, Tambora in Indonesia, El Chichon in Mexico and studies of deadly gas bursts from Cameroon crater lakes. He has also studied the global environmental effects of meteorite impacts, such as the one that marks the Cretaceous/Tertiary boundary. His books include Melting the Earth, accounting for the evolution of ideas about formation of magmas and the origin of volcanic eruptions. Haraldur is currently director of the Volcano Museum in Stykkisholmur, Iceland. Read More Read Less