Follow-up to the last post

On November 6th, I wrote a bit about what I thought could happen once mining companies begin to feel the squeeze of depleting reserves of various minerals. I pointed out that scarcity in this sector can easily result in economic trade wars between nations with abundance of the particular mineral and those without. China was an example where this may be already happening with regard to rare earth minerals. By the end of my post, I was assuming that mining will eventually run into scarcity problems in conventional mines and I posed a question about where mining companies will explore next: landfills or the ocean floor?

Well it seems I've received at least a preliminary answer. Six days after my post, on November 12th, Popular Science ran a piece about mining prospectors looking at the ocean floor for new mineral reserves (They cited an article from the NY Times which was published Nov. 8th, but it's behind a pay-wall). According to Popular Science, mineral nuggets, called manganese nodules, are fairly common on the sea floor and contain a myriad of minerals other than manganese, including rare earth minerals. They contain gold and copper in concentrations much higher than ores found on land. Geologists say these nodules are remnants of hydrothermal vent activity, and they indeed find the most nodules near active vents. Some comments on the Pop Sci article claim that sea floors have an advantage over conventional mining locations, because sea floors lack any overburden. Overburden is the soil and plant life that must be displaced before mining can take place. Displacing overburden is one of the major environmental costs of conventional mining.

Popular Science cited the economics of mining and the scarcity of various minerals for the renewed interest in sea floor mining. They specifically referred to China's virtual monopoly on global rare earth mineral production as prompting other countries to look for alternative mineral sources.

Companies like Canadian Nautilus Minerals have apparently been way ahead of us on this one. They've been looking into sea floor mining prospects as far back as 1985, at least in a research capacity. Their website prioritizes gold and copper above any rare earth minerals, but they also will retrieve silver and zinc. But once robots are sent below, they may as well bring back everything they can, I suppose.

Robot sampling marine rock outcrop for mineral content.
(Copyright Nautilus Minerals, Reproduced here under Fair Use.)

It's true that robotic technology, like that pictured above, is sophisticated enough to do this and stands to gain from innovation motivated by the push for marine mining. It's true that the economics are leaning towards sea floor mining more every day. But there are still very many unknowns about the process. And estimating consequences for marine life has yet to be done and will probably be difficult.

I will withhold judgment on the wisdom of this for know. But I am disappointed that the other mining alternative, landfills, is not being considered for comparison with mining the sea floor.

*Update: I shouldn't be surprised that the idea of ocean floor mining has been around for a long time. Discover Magazine published a great article in May 2009, and talked about ideas of this sort back in the 1920's. Discover Mag's article does a great job of profiling Nautilus Minerals.