Harald Ingemann Jensen was born in 1879 in Denmark and migrated to Queensland at the age of 6. In 1898 he was employed at Clement Wragge's Mt Kosciusko observatory and entered the University of Sydney. He taught in Sydney and North Queensland in 1900-1901, then returned to the University of Sydney and graduated in 1904 with BSc with honours in geology. Jensen was assistant demonstrator, geology and chemistry, under Edgworth David in 1904-1905; appointed first Macleay Fellow, Linnean Society of New South Wales in 1905; awarded D Sc & university medal in 1908; and from 1908-1911 worked as a soil scientist with the New South Wales Department of Agriculture. Jensen was an active member of the Australian Labor Party (ALP) and wrote regularly for Labor and union journals. In August 1912 he was appointed director of mines in the Northern Territory, holding the position until 1915 when he was demoted to Chief Geologist. From 1917-1922 he was a government geologist in Queensland. Jensen was defeated as ALP candidate for Lilley (1917) and the Queensland Senate (1922 and 1925). He was later expelled by the ALP Queensland central executive for his critique of the party's neglect of socialism. From 1923-1938 he worked as a consultant geologist, seeking oil in the Roma basin, Queensland, and the Mandated Territory of New Guinea. In 1938-1940 he led the Queensland section, Aerial Geological & Geophysical Survey of North Australia. From 1943-1956, he worked on weather prediction with Inigo Jones at his Crohamhurst laboratory. Jensen died after sustaining burns on 13 July 1966.