Norwegian Geological Survey, or Norges geologiske undersøkelser (official site) Research and survey related to geology.

He also helped the Norwegian Geological Survey with Sami place names.

He worked at the Norwegian Geological Survey from 1968 to 1984, and was then a professor at the University of Oslo from 1984 to 1994.

He then returned to the Norwegian Geological Survey as managing director from 1994 to 2006 and senior researcher from 2006 to 2009.

Between 1989 and 1992, the Norwegian Geological Survey conducted mineral exploration studies at the site of Ødegården Verk.

He worked for the Norwegian Geological Survey from 1889 to 1905 and the Norwegian College of Agriculture from 1898 to 1931.

He worked in the Norwegian Geographical Survey from 1897 to 1918, and issued several maps of different places in Eastern Norway.

In the same year, he became director of the Norwegian Geological Survey, which he had been instrumental in establishing.

From 1974 to 1994 he presided over the Norwegian Geological Survey.

Without a formal examination, he wrote the paper Øxer av Nøstvettypen, which was released in 1905 by the Norwegian Geological Survey.