Study suggests water may exist in Earth’s lower mantle

Water on Earth runs deep – very deep. The oceans have been measured to a maximum depth of 7 miles, though water is known to exist well below the oceans. Just how deep this hidden water reaches, and how much of it exists, are the subjects of ongoing research.

Now a new study suggests that water may be more common than expected at extreme depths approaching 400 miles and possibly beyond – within Earth’s lower mantle. The study, which appeared March 8 in the journal Science, explored microscopic pockets of a trapped form of crystallized water molecules in a sampling of diamonds from around the world.

Diamond samples from locations in Africa and China were studied through a variety of techniques, including a method using infrared light at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). Researchers used Berkeley Lab’s Advanced Light Source (ALS), and Argonne National Laboratory’s Advanced Photon Source, which are research centers known as synchrotron facilities.

>Read more on the Advanced Light Source website

Photo: Oliver Tschauner, professor of research in the Department of Geoscience at the University of Nevada, Las Vegas, holds a diamond sample during a recent round of experiments at Berkeley Lab’s Advanced Light Source.
Credit: Marilyn Chung/Berkeley Lab