What causes earthquakes? Earth's crust ranges from 3 to 45 miles deep (5 to 70 kilometers). The crust is a thin, hard shell that floats on the denser, hotter rock of the mantle.
Sponsored Topics. Airway Heights is a city in Spokane County, Washington, United States, just west of Spokane. The population was 6,114 at the 2010 census. The city's name was taken from its close proximity to Fairchild Air Force Base and Spokane International Airport. Airway Heights was officially incorporated on June 28, 1955.
Union Gap, Washington. Union Gap redirects here. For the music group, see Gary Puckett & The Union Gap. Union Gap is a city in Yakima County, Washington, United States. As of the 2010 census, the city population was 6,047. Union Gap has a storied history and in recent years has become the retail hub for the entire Yakima Valley as a result of Valley Mall and other thriving businesses being located here.