Image: Wikipedia, CC
Mining 20,000 Leagues Under the SeaIt looks like two stories from the past year are combining into something that could both help the environment and damage it (probably more of the latter than former, sadly). China has been restricting exports of rare earths, leading to a doubling of prices, and Japan has been exploring the ocean floor, looking for underwater mining opportunities. Well, it looks like they've found a huge rare earths deposit, a source that could potentially make them independent from their ascending neighbor. But what would the repercussions be on marine ecosystems?
Rare earth ore. Photo: USGS, Public domainThe rare earths have been found at depths of 3,500 to 6,000 meters (11,500-20,000 ft) below the ocean surface at 78 locations in international waters in an area stretching east and west of Hawaii, as well as east of Tahiti in French Polynesia.
"The deposits have a heavy concentration of rare earths. Just one square kilometer (0.4 square mile) of deposits will be able to provide one-fifth of the current global annual consumption," said Yasuhiro Kato, an associate professor of earth science at the University of Tokyo.
The discovery was made by a team led by Kato and including researchers from the Japan Agency for Marine-Earth Science and Technology. [...]
He estimated rare earths contained in the deposits amounted to 80 to 100 billion tonnes, compared to global reserves currently confirmed by the U.S. Geological Survey of just 110 million tonnes that have been found mainly in China, Russia and other former Soviet countries, and the United States.
Ocean Floor Destruction?
The mining process requires that mud from the ocean floor be pumped up to shops where rare earths are extracted using simple acid leaching ("Using diluted acid, the process is fast, and within a few hours we can extract 80-90 percent of rare earths from the mud.").
Trawlers are already bad enough, leaving behind a lifeless trail of destruction. If this type of ocean floor mining is anything like it, and if the ships that process the ore release toxic materials, this type of mining should be stopped, at least until it can be shown to be ecologically responsible.
More on Rare Earth Materials
Rare Earth Prices Double on China Restrictions
China Will Cut Rare Earths Exports by 10% in 2011
Rare Earth Element Mining is Re-Starting in the U.S. to Break China's Near-Monopoly