Wallace Raymond ('Wal') Ambrose was born in Auckland, New Zealand in 1933. He began his education as an artist, at Seddon Technical College, followed by the Elam School of Art, at the time a part of Auckland University College, where he earned a Diploma of Fine Arts in 1953. He was awarded the Postgraduate Diploma of the Auckland Teachers College in 1955, for the art teachers' course.
A chance encounter that year with members of the University Archaeological Society summer excavation season saw Wal begin what would become a lifelong interest in archaeology. During the following year, Wal continued his involvement with the Society, and in 1956, the Department of Anthropology hired him as photographer and cartographer.
Wal Ambrose became the organiser and site supervisor for all of Jack Golson's excavations during his time at the University of Auckland. He also participated in excavations with Roger Green and Wilfred Shawcross in New Zealand during between 1957 and 1963. He directed the departmental excavations at the Kauri Point site in 1961-1962. He conducted three seasons of salvage work recording rock art for New Zealand National Historic Places Trust.
Ambrose also was a member and served in a variety of offices for the University Archaeological Society and the New Zealand Archaeological Association, including as editor of the quarterly NZAA newsletter. During this time Ambrose also earned his university degree at the University of Auckland, in anthropology and geology.
In 1963, he joined the then Department of Anthropology and Sociology in the Research School of Pacific Studies at the Australian National University as a Research Assistant where Jack Golson had recently accepted a position. Ambrose completed a Diploma of Archaeological Conservation at the London Institute of Archaeology in 1965. Ambrose was a pioneer in the field of archaeological conservation in Australia, writing many articles and manuals on the deterioration and conservation of materials, and playing a leading role in the establishment of the Institute for the Conservation of Cultural Material. When the new department of Prehistory was established in the Research School at ANU, Wal Ambrose’s position was reclassified as Research Officer in Conservation and Experimental Archaeology in 1966. At the same time, realising the need to stabilise artifacts, the Department of Prehistory established a Conservation section, and remains the only archaeology department in Australia to maintain a dedicated conservator on staff. In 1970 he was seconded to the Anthropology Department of the University of Papua New Guinea. In 1982, his position at the Australian National University was that of Experimental Archaeologist, which would continue until his retirement in 1998, at which point he became a Visiting Fellow of the Department of Archaeology and Natural History.
Wal Ambrose was greatly involved in the ANU excavations at Kuk, led by Jack Golson, now a UNESCO World Heritage site for establishing the independent development of agriculture in Papua New Guinea. Ambrose created methods for freeze drying the wooden artifacts being excavated from the Kuk swamp, a process that was successful in maintaining the original form of the artifacts, including marks of manufacture and use. His revolutionary treatment has now been widely adopted and recognised by the Cellulose, Paper and Textile Division of the American Chemicals Society and the Archaeological Materials Working Group of the International Council of Museums. Ambrose also developed and patented his invention for a temperature and relative humidity monitoring device for long-term soil monitoring, which was used to a great extent at Kuk and on many ANU-led excavations throughout the region, and humorously and fondly known throughout the department as “Wall’s balls” for their spherical shape.
Ambrose’s experiments with freeze drying technology led to expeditions to Antarctica, to test freeze drying without a vacuum chamber in dry, cold conditions. Ambrose’s venturi system, which allowed for air suction, was proved a success and was later patented. His findings have led to different approaches to the conservation of Antarctic heritage buildings. Ambrose patented his invention for a temperature and relative humidity monitoring device, which was
Ambrose also contributed greatly to obsidian studies. He amassed a large collection of obsidian samples, which were then tested using emission spectography. Ambrose collaborated with scientists from the Australian Atomic Energy Commission to develop PIXE/PIGME analytical system to differentiate the composition and original location of the obsidian samples. The PIXE/PIGME system became standard for obsidian study, and Wal Ambrose’s collected obsidian samples became a reference file for the composition of Pacific obsidians based on that system. Ambrose was also at the forefront of obsidian dating, especially in hydration dating.
Wal Ambrose was involved in many excavations during his long career at the Australian National University including: Northern Territory (1963); Dorset (University of London, 1964-1965); various locations in the Papua New Guinea Highlands, including Kuk (1966, 1968); Kauri Point, NZ (1967); Anir Island, New Ireland, PNG (1970-1971); Kuk, PNG (1972); survey of all known obsidian source sites in Papua New Guinea (1974); Admiralty Islands (1977), Lou and Hus Island, Admiralty Island (1978); Lou, Baluan, and Manus, Admiralty Islands (1981); Manus, New Ireland, New Britain (1984); Lou Island, Manus and Boduna Island, Talasea (1985); Baluan Island, Manus, and Schouten Islands (1987); Pamwak rockshelter, Manus Island (1989, 1990); Antarctica, experimental freeze-drying project (1990/1991); Assessment of historic building preservation at Wilkes Station Antarctica (1994).
After retiring as Experimental Archaeologist with the Australian National University department of Prehistory, Wal Ambrose became a visiting fellow of the new Archaeology and Natural History department, and later pursued his PhD. His Doctor of Letters was awarded by the Australian National University in 2006. Wal Ambrose died in January 2024.