Continental drift is created at spreading centers, and this, along with subduction, drives the system of plates in a chaotic manner, resulting in continuous orogeny and areas of isostatic imbalance. The theory of plate tectonics explains all this, including the movement of the continents, better than Wegener's theory. Hans Stille and Leopold Kober opposed the idea of continental drift and worked on a "fixist" geosyncline model with Earth contraction playing a key role in the formation of orogens. Other geologists who opposed continental drift were Bailey Willis, Charles Schuchert, Rollin Chamberlin and Walther Bucher. In 1939 an international geological conference was held
Institute for the Study of the Americas English Studies and Institute of Historical Research. Institute for the Study of the Americas The Institute for the Study of the Americas (ISA) was established in 2004 following a merger of the Institute of Latin American Studies and the Institute of United States Studies. ISA formed part of the University of London’s School of Advanced Study along with nine other research institutes. In 2013, the Institute of Latin American Studies was re-established in order to focus the support provided to scholars of Latin America. Activities pertaining to the study of the United States continue within the School of Advanced Study