Photogeologic reconnaissance of X-tunnel at Little Skull Mountain

On June 29, 1992, a magnitude 5.6 earthquake occurred immediately to the south of Little Skull Mountain; the depth of the shock was about 9 kilometers (6 miles). It is the location of an underground structure known as X-tunnel, that once supported deep basing studies for the Air Force in the 1980s. The Nevada Operations Office of US DOE authorized access to the facility on several occasions to allow technical specialists from the Yucca Mountain Site Characterization Project, including geoscientists and engineers, to gather information about possible damage related to the earthquake. Examination of the underground facility in the vicinity of Yucca Mountain indicated little or no damage to the facility. Photogeologic reconnaissance affirmed that the potential for damage to underground facilities is moderated and attenuated by depth below the ground surface