Offshore mining platform. Photo credit: Nautilus Minerals
When most people think of mining they imagine terrestrial mining operations consisting of earth moving machines designed to dig down to bedrock to extract gold, coal, or diamonds. Offshore mining, also called Deep Sea Mining, is a rather new method of extracting precious materials from the ocean floor. Raw materials present on the sea floor include gold, silver, copper, cobalt, zinc and diamonds and are often found in concentrations much higher than those found on land. Precious metals and stones are often found near alluvial deposits, volcanic belts and underwater mountains. Until recently, the technology needed to efficiently mine underwater was not available. Mining dredges have been around since the early 1900s, however, the Remotely Operated Vehicles (ROVs) necessary to explore the most valuable underwater claims are a relatively new innovation.
The single largest factor which has held back underwater mining has been the cost of operating an offshore mine. Commissioning a dredge ship, crew, fuel and rolling the dice on mining untested ocean floor is too risky to invest in. But the economics of offshore mining are changing. Rare earth minerals are being consumed at a rapid rate to manufacture devices such as cell phones and solar panels. British scientists recently discovered Tellurium deposits off the coast of the Canary Islands which have concentrations 50,000 times higher than land deposits, according to the BBC. Tellurium is used in the construction of solar panels and semiconductors, and discoveries like this are critical to meet the growing demands in these sectors.
Tropic Seamount with Tellurium deposits. Photo credit: NOC/NERC
The efficiency of offshore mining exploration is improving as well. Prospectors of the 21st century don’t carry a pick-axe or a gold pan, they carry remotely operated vehicles to explore, probe and test sample materials brought back from the depths of the ocean. The more samples that can be collected, the more confident a prospector can be of the density of target minerals. This means that fleets of remotely operated vehicles are needed to pinpoint the richest areas of ocean crust before any mining can occur. The use of on-board cameras, drills, and sample collectors are critical tools to deploy while prospecting. Once an offshore mine is established, inspection class ROVs become an important way to monitor the condition of mining equipment from the safety of the surface.
Offshore mining is still in its infancy, and it’s a highly controversial subject. The ocean belongs to us all, and marine environments can be complex and delicate. We are now presented with a social dilemma: continue to mine on land and strip large areas down to bedrock, or carefully pinpoint the most concentrated marine deposits and do everything possible to minimize environmental impact. Before any mining can occur, environmentally-conscious contracts are signed between miners and the nations or states which own off-shore resource rights.
Offshore mining is the last frontier on Earth for the discovery of rare earth minerals, many of which will be necessary for our transition on to more renewable forms of energy. The more we know about the ocean floor the better prepared we will be to make decisions around the responsible harvest of these raw materials. ROVs are providing the data necessary to open our world to the possibilities of offshore mining.