Career
He participated in Amdrup"s expedition to east Greenland in 1900 and was one of the general staff of the surveying expeditions to Iceland in 1903-1904. On the death of Mylius-Erichsen and two others on a long sled voyage from Danmarkshavn to Peary Land, Koch along with the Greenlander Tobias Gabrielsen searched for the lost party, and found only the Greenlander Jørgen Brønlund on whose body was recovered hand drawn charts which completed the map of Greenland. Koch later led a sled expedition across the inland ice of Greenland in 1912-1913, with Alfred Wegener.