Aside from its primary aim of using two aircraft to carry out an extensive aerial photogrammetric survey of the unexplored hinterland of Dronning Maud Land, the Third German Antarctic Expedition of 1938-39 aboard MV Schwabenland also collected numerous meteorological and oceanographic measurements during its voyage to and from Antarctica. Among the newest scientific equipment available for this short summer campaign was an underway echo-sounder to map the depth of the seabed, allowing the crew to escape from the tedium of stopping to take soundings with a lead-line. Schwabenland was one of the first three scientific research vessels to use echo-sounding to map the sea floor of the South Atlantic, the others being the Meteor (1925-27) and the Discovery-II (from 1930 onwards). Schwabenland’s soundings were the first to discover submarine channels that form the heads of Antarctic submarine canyons. Schwabenland also made the first axis-parallel bathymetric profile down a mid-ocean ridge, displaying its rugged nature; confirmed the existence of a median rift in the South Atlantic branch of the mid-ocean ridge; and discovered that the floor of the South Polar Basin was more or less flat, a characteristic later recognised as typical of abyssal plains. It took years to realise the full significance of the echo-sounding profiles. The expedition’s geographer, Ernst Herrmann, was a geologist with expertise in volcanic studies. He interpreted the mid-ocean ridge, apparently for the first time, as a continuous volcanic structure. Although he was right about the ridge being made of basalt, he was wrong about the details of the ridge’s formation. In any case, he got no credit for his imaginative proposal, mainly because it was published in German in his travel account. In honour of the expedition, a South Atlantic seamount was named after the ship, and four Antarctic submarine canyons were named after the ship, the expedition leader Alfred Ritscher, the leader of the echo-sounding team Ernst Herrmann, and after the ship’s ice pilot Otto Kraul.

This presentation is based on work co-authored by Colin Summerhayes.