Final answer:
To extract the remaining fragments of the Ara Pacis, archaeologists used advanced soil freezing technology in 1937, which allowed the artifacts to be safely removed without damage.
Step-by-step explanation:
The advanced technology used by archaeologists to extract the last remaining fragments of the Ara Pacis from the soil was the method of soil freezing. This technology was utilized in 1937 during excavations mandated by the Italian government under Benito Mussolini, in preparation for the planned jubilee of 1938 that intended to commemorate the 2,000th anniversary of Augustus' birth.
Approximately 70 cubic meters of soil was frozen to facilitate the safe removal of the fragments, an innovative approach of the time that allowed the sensitive procedure to proceed without damaging the relics. In February 1937, approximately 70 cubic meters of soil were frozen to allow for the extraction of the remaining fragments. This excavation was mandated by the order of the Italian government in preparation for a planned jubilee in 1938.