China News Service, Beijing, September 27 (Reporter Sun Zifa) Springer Nature's professional academic journal "Nature-Earth Science" recently published a research paper saying that researchers analyzed rare diamonds 660 kilometers below the surface. Inclusions, the discovery of a widespread water-saturated environment extending into the lower mantle, this research may improve people's understanding of the water cycle in the deep Earth.

  Earth is sometimes called a water planet because oceans cover 70 percent of the surface, the paper says.

Ocean water can be transported to the Earth's depths by hydrous minerals until volcanic activity brings it back to the surface again - a process known as the deep water cycle.

Water at these depths can affect the explosiveness of volcanic eruptions, as well as the nature of seismic activity and plate tectonics.

However, sampling and studying the Earth's deep water cycle is difficult because boreholes on the surface are currently only a little over 12 kilometers deep.

  Co-corresponding authors of the paper, GIA Gu Tingting, Fabrizio Nestola of the University of Padova, Italy, and collaborators studied a gem-quality diamond from the Karowe mine in Botswana, where it was During its journey to the surface at a depth of about 660 kilometers, the interior contains and protects samples of the Earth's lower mantle.

They found signs of spinel and other water-bearing minerals (phases), suggesting that it formed in a water-bearing region of the mantle.

  The authors concluded that the diamond confirms the widespread presence of water at a depth of 660 kilometers on Earth, and also suggests that mineral-bound water may be present at greater depths.