Comment by vixen99

To put this in perspective, ringwoodite in the mantle is estimated to hold up to 1% water. If estimates are correct this implies it holds three times more water than all of the oceans on the Earth's surface.

https://en.wikipedia.org/wiki/Ringwoodite http://www.hpstar.ac.cn/upload/files/2020/2/fab59e098740ea9c... https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL09...