compressional wave transit time
1Geology of the Grand Canyon area — The geology of the Grand Canyon area exposes one of the most complete sequences of rock anywhere, representing a period of nearly 2 billion years of the Earth s history in that part of North America. The major sedimentary rock layers exposed in… …
2Milky Way — This article is about the galaxy. For other uses, see Milky Way (disambiguation). Milky Way galaxy Image of the Milky Way s Galactic Center in the night sky above Paranal Observatory Observation data …
