They were unspooling Earth's history, raising up sections of sediment and ancient rock from beneath the South Pacific. "The workings of the oceans, the Earth's environment and climate are all recorded in the sediments," explained Anthony Koppers, a professor of marine geology at Oregon State University. Drill beneath the sediment on the sea floor and you hit the oceanic crust. One advantage of drilling into oceanic crust is it's approximately 7 kilometers thick, while on land it is many times thicker, explained Koppers. That allows scientists to sample closer to the Earth's mantle.

Source: CNN February 04, 2020 09:33 UTC