Chapter 3—Containing Underground Nuclear Explosio Box 3-A—Baneberry The exact cause of the 1970 Baneberry venting still remains a mystery. The original explanation post the existence of an undetected watertable. It assumed that the high temperatures of the explosion produced: that vented to the surface. Later analysis, however, discredited this explanation and proposed an alternative sce based on three geologic featuresof the Baneberry site: water-saturated clay, a buried scarp of hard rock, and an fault. It is thought that the weak, water-saturated clay was unable to support the containmentstructure; the hard strongly reflected back the energy of the explosion increasing its force: and the nearby fault provided a pat that gases could travel along. All three of these features seem to have contributed to the venting. Whatever its c the Baneberry venting increased attention on containmentand,in doing so, marked the beginning ofthe presen containmentpractices. Photo credit Department o The venting of Baneberry, 1970.