A seabed off of Japan contains more than 16 million tons of rare-earth oxides, according to the study. That's equivalent to 780 years' worth of yttrium supply, 620 years of europium, 420 years of terbium and 730 years of dysprosium

Nature Scientific Reports – The tremendous potential of deepsea mud as a source of rare-earth elements

Potential risks of supply shortages for critical metals including rare-earth elements and yttrium (REY) have spurred great interest in commercial mining of deep-sea mineral resources. Deep-sea mud containing over 5,000ppm total REY content was discovered in the western North Pacific Ocean near Minamitorishima Island, Japan, in 2013. This REY-rich mud has great potential as a rare-earth metal resource because of the enormous amount available and its advantageous mineralogical features. Here, we estimated the resource amount in REY-rich mud with Geographical Information System software and established a mineral processing procedure to greatly enhance its economic value.