The elevated mode will keep the heat of the oil from penetrating the ground in areas where the permafrost, or permanently frozen ground, would be rendered unstable upon thawing., 1977-01, PCA0002-4a-17, Folder: PCA0002-4a. Alyeska Pipeline Service Company : Trans-Alaska Pipeline Construction Collection, 1976-1977, PCA 2. Alaska State Library - Historical Collections Finding Aids. https://alaska.libraryhost.com/repositories/2/archival_objects/17728 Accessed February 22, 2025.