"Steve" Stephenson read Geography at St Catharine's College, Cambridge, and his contact there with Professor Frank Debenham, who had been on Scott's second Antarctic Expedition, ignited his enthusiasm. The friendship with Debenham, and subsequently his family, continued over many years.
Immediately after graduating in 1930, he joined the British Arctic Air Route Expedition to Greenland as chief surveyor. The expedition mapped a strategic area of Greenland that was potentially important as part of the Great Circle air route between the British Isles and North America. To some extent, developments in the capabilities of aircraft overtook their work, but the detailed surveying of the eastern coast, the coastal mountain ranges and the inland ice-cap, in difficult polar conditions, provided new and detailed information. For this work he was awarded the Polar Medal.
Though not an experienced climber, Stephenson and his companion Laurence Wager reached a height of 10,950ft on Mount Forel but thought it unwise, due to tiredness, to attempt the final 550ft of the mountain. This altitude stood as a record in Greenland for many years.
He returned to northern polar areas in 1932 as a member of the British Polar Year Expedition, but two years later he had the chance to go to the Antarctic with the British Graham Land Expedition (BGLE), as chief surveyor and meteorologist.
This small group of young enthusiasts was the link between the heroic age of Antarctic exploration before the First World War and the present government-funded Antarctic research. Their funds were scant and recently one of their number, the biologist Colin Bertram, described the members of the expedition as " `Obligate Pinnipedophagi' (that is, `necessarily seal-eaters')". Because of their precarious funding, they went south knowing they had to live off the land if they were to survive.
Southern Lights (1938) , the official account of the expedition, was mainly written by its leader, John Rymill, but Stephenson contributed two chapters describing sledge journeys, frequently travelling to areas that had not previously been visited. The second was southwards to 72 degrees 14 minutes South, and proved that Graham Land (now the Antarctic Peninsula) was a peninsula of the continent, rather than an archipelago, as previously thought.
For this pioneering surveying Stephenson received the rare distinction of an Antarctic clasp to his Polar Medal. While his passages in the book accurately describe the sledge journeys and the landforms located, they go beyond purely physical details, and convey in lucid prose an impression of the whole landscape. When the expedition left in March 1937, no humans remained on the continental block of Antarctica.
On his return, Stephenson joined Imperial College, London, as a Lecturer in Surveying, but then war service in the RAF took him to the Central Allied Photo Interpretation Unit, which he ultimately led, providing intelligence about strategic targets, military movements and damage assessment. He was appointed OBE for this work.
In 1945 he rejoined Imperial College, where he remained until his retirement in 1972. He was heavily involved with the Royal Geographical Society (RGS), serving on their Expeditions Committee, and was a founder member of the Young Explorers' Trust, which was designed to give young people the chance to experience expeditionary work.
Any passive interpretation of "retirement" was unknown to him. He and his wife Roma moved to Seend in Wiltshire and entered into many aspects of community life, including acting as Treasurer of the Parochial Church Council. In 1982 he visited Greenland again, and two years later, on the 50th anniversary of the BGLE, returned to the Antarctic Peninsula with Colin Bertram as guests of the British Antarctic Survey.
From their base at Rothera Point he was taken on a flight south to Fossil Bluff on King George VI Sound, which he and his companions had visited and mapped 48 years previously. He saw again Mount Stephenson, the highest peak (3,100m) in the Douglas Range on the east of Alexander Island, and Stephenson Nunatak, further south, both named after him. In later life he commented that there was also a mountain in Greenland designated to bear his name, but that confirmation of this could only take place after his death.
His interest and involvement in the Antarctic continued long after he had brushed off the snow of his own expeditions. In 1956 he became Secretary of the Antarctic Club, only the second person to hold the position, and he remained until 1996, bringing to it phlegmatic good humour, efficiency and organising abilities. To mark his 40 years of service, the club established the Stephenson Award, given annually for "outstanding service to youth expeditioning".
In the 1950s, he was responsible for the training of Antarctic surveyors for the Falkland Islands Dependencies (later the British Antarctic Survey), running courses with emphasis on astronomical surveying, essential to position-finding before the days of satellite navigation.
In the case of one aspiring surveyor, because of shortage of time before sailing, Stephenson's instruction was given in his office at the RGS. The theodolite observations were carried out on the roof of the building, where the spires and towers of London played the part of Antarctic mountains and nunataks, and the stars of the northern hemisphere substituted for those of the south. He was a man of immense expertise and great patience. In many cases the mentor of the 1950s became the good friend of the next 40 years.
His memory of polar areas was impressive. In 1997 he was shown a photograph of a narrow channel in the Argentine islands, alongside the BGLE's original base camp 60 years previously. After a reflective pause, he asked if the steep ice cliff was immediately to the left of the photographer's position, and was not surprised to receive confirmation that it was.
Steve and Roma Stephenson were generous in their hospitality, whether to students in London, or polar friends and other visitors to their homes in Seend and later Lymington in Hampshire. Earlier this year they celebrated their diamond wedding anniversary, joined by three generations of their family. It was fitting that his last "polar" visitors were two daughters of the late Professor Debenham. This was shortly before he was admitted to hospital, where eight days later he died.
Alfred Stephenson, polar explorer and surveyor: born Norwich 25 November 1908; OBE 1949; married 1939 Roma Johnson (one son, one daughter); died Southampton 3 July 1999.