Otto Volger  Georg Heinrich Otto Volger (30 January 1822 – 18 October 1897) was a German geologist born in Lüneburg. He studied natural history at the University of Göttingen, and later taught classes in natural history at the Muri monastery in Aargau. From 1851 to 1856 he was a professor of natural history at the ETH Zurich, and afterwards taught geology at the "Forschungsinstitut Senckenberg". From 1859 to 1881 he taught geology and mineralogy at the "Freie Deutsche Hochstift" in Frankfurt-am-Main. Volger made contributions in the fields of mineralogy and crystallography, and was particularly interested in earthquakes. He did extensive study of earthquakes in Switzerland; researching their origins, periodicity, meteorological and environmental factors, as well as the spread and expansion of the quakes. Volger advocated the theory of neptunism. Independent of geologist Robert Mallet (1810-1881), he created his own neptunistic theory of wave propagation of earthquakes. Volger believed that most earthquakes in Switzerland were subsidence quakes caused by collapse of layers of hollow strata in the Earth. In 1863, Volger purchased the birthplace of Johann Wolfgang von Goethe (1749-1832), and meticulously restored the house to the condition left by Goethe's father.