The Challenger expedition of 1872–1876 studied processes of the sea floor. In 1889 Andrusov published a review of this expedition in the Mining Journal. He would later perform studies of the geology and sediments of the Caspian Sea and the Black Sea.
In 1890-91 he participated in a deep water expedition to the Black Sea by the Russian Geographical Society. This expedition discovered hydrogen sulfide in the lower portions of this sea. Andrusov was the first to propose that this substance was created by biological decomposition of life forms (bacteria) containing sulfurous compounds.
He was married to Nadezhda Genrikhovna Schliemann in 1899, the daughter of the somewhat notorious archaeologistHeinrich Schliemann. In 1905 he became a professor at the University of Kiev. In 1914 he became a member of the Russian Academy of Sciences. He emigrated to France in 1920 due to illness. In 1919 he learned about the death of his elder son, and suffered a stroke which resulted in paralysis of a leg and an arm. His relatives decided to move him to Paris, where he had an inheritance from his father-in-law. In 1922 he moved to Prague due to material difficulties, where he died in 1924.