Ampferergasse (Oberlaa), named in 1956 after the geologist Otto Ampferer (1875–1947), who worked at the Imperial and Royal Geological Institute in Vienna from 1901 and was its director from 1935 to 1937. To explain the complex processes of mountain formation, he developed his undercurrent theory, based on the then-new notion of a partially plastic Earth’s crust. According to this theory, mountain formation is due more to the effects of currents of viscous, high-pressure, high-temperature masses beneath the Earth’s crust than to forces within the Earth’s crust. Thus, he became a pioneer of the modern concept of mobilism—even before Alfred Wegener. The street was previously called Beethovengasse.