Deep sea mining
Seabed mining (short- sea mining, in the area called the deep sea and deep seabed mining ) is mining, that is, the exploration, development and feeding of mineral raw materials ( natural resources ), on and under the seabed.
Natural resources
Metal raw materials (ores )
On and under the seabed there is due to the different chemical and physical environment of significant deposits of some ores and polymetallic mineral aggregates of metals that occur in the Earth's crust on land rarely or usually in small, non- mineable concentration:
- Ore slurry at plate boundaries
- Cobalt rich crust on deep-sea knolls and areas with volcanic activity
- Deep-sea nodules: manganese
- Nickel, cobalt, copper
Fossil energy resources
For a long time spread is the extraction of fossil fuels for energy but also the recycling of the ground under the sea.
- Petroleum
- Natural gas
- Methane hydrate (so far hardly, but high future potential)
The development of resources is usually done by a drilling rig or drillship, then the funding is received from a production platform from the water surface.
Mass materials ( rocks and soils )
In shallow coastal water partially mass raw materials such as sand or gravel are obtained with dredgers, which are mainly used as building material.
Environmental problems
Because of the enormous expense marine mining is mainly operated by highly industrialized countries, most notably Japan. To work efficiently, the deep seabed mining must encourage large quantities of ore: currently 5000 tonnes of manganese nodules ( wet) per day and per mining unit.
At least 1 km can be degraded ² of seabed per 5000 t of manganese nodules, which brings environmental problems:
- Mechanical destruction of soil by mining equipment
- Formation of a turbidity cloud, where benthic organisms (eg sponges ) are covered by sudden sedimentation
- Disturbance of the biological equilibrium in the deep sea by mineral extraction