Deep Ocean Mission

Context: India will soon launch an ambitious ‘Deep Ocean Mission’ that envisages exploration of minerals, energy and marine diversity of the underwater world

  • The ‘Deep Ocean Mission (DOM)’ to be led by the Union Earth Sciences Ministry.
  • The mission, which is expected to cost over ?4,000 crore, will give a boost to efforts to explore India’s vast Exclusive Economic Zone and Continental Shelf
  • A major thrust of the mission will be looking for metals and minerals.

Analysis

  • India has been allotted a site of 75,000 sq. km. in the Central Indian Ocean Basin (CIOB) by the UN International Sea Bed Authority for exploitation of polymetallic nodules (PMN).
  • These are rocks scattered on the seabed containing iron, manganese, nickel and cobalt.
  • Being able to lay hands on even 10% of that reserve can meet the energy requirement for the next 100 years.
  • It has been estimated that 380 million metric tonnes of polymetallic nodules are available at the bottom of the seas in the Central Indian Ocean.
  • India’s Exclusive Economic Zone spreads over 2.2 million sq. km. and in the deep sea, lies “unexplored and unutilised”.

Polymetallic Nodules

  • Of all the mineral resources considered as potential targets for deep-sea mining, polymetallic nodules (also commonly called manganese nodules) are probably the most likely commodity to be developed into a commercial operation.
  • These are rounded accretions of manganese and iron hydroxides that cover vast areas of the seafloor, but are most abundant on abyssal plains at water depths of 4000-6500 metres.
  • They range in size from a few millimeters to tens of centimeters.

How do nodules grow?

  • Manganese nodules grow when metal compounds dissolved in the water column (hydrogenous growth) or in water contained in the sediments (diagenetic growth) are deposited around a nucleus.
  • Most nodules are a product of both diagenetic and hydrogenous growth.
  • Growth of these nodules is extremely slow, at a rate of millimetres per million years, and they remain on the seafloor surface, often partially buried in a thin layer of sediment.
  • This means that manganese nodules can only grow in areas where the environmental conditions remain stable over this kind of time scale.

The following factors are essential for the formation of manganese nodules:

Low sedimentation rates of suspended material.

  • Otherwise the nodules would be covered too rapidly;

Constant flow of Antarctic bottom water.

  • This water flushes fine sediment particles away that would otherwise bury the nodules over time.
  • The coarser particles, such as the shells of small marine organisms and clam or nodule fragments, may be left behind to act as nuclei for new nodules;

    Good oxygen supply
  • The Antarctic bottom water, for example, transports oxygen-rich water from the sea surface to greater depths. Without this the manganese oxide compounds could not form;

    Aqueous sediment.
  • The sediment has to be capable of holding large amounts of pore water.
  • Diagenetic nodule growth can only take place in very aqueous sediments.
  • Furthermore, some researchers hold the opinion that bottom-dwelling organisms such as worms that burrow around in the sediment must be present in large numbers in order to constantly push the manganese nodules up to the sediment surface.
  • This hypothesis, however, has not yet been proven.

Composition

  • The composition of nodules varies with their environment of formation, but in addition to manganese and iron, they can contain nickel, copper and cobalt in commercially attractive concentrations as well as traces of other valuable metals such as molybdenum, zirconium and Rare Earth Elements.
  • In part, the manganese nodule deposits are of interest because they contain greater amounts of some metals than are found in today’s known economically minable deposits on land.
  • Although the conditions for the formation of manganese nodules are the same in all four of the major regions, their metal contents vary from place to place. 

Distribution

  • Manganese nodules occur in all oceans. But only in 4 regions is the density of nodules great enough for industrial exploitation.

Clarion-Clipperton Zone (CCZ):

  • With an area of around 9 million square kilometres, approximately the size of Europe, this is the world‘s largest manganese nodule region.
  • The CCZ is located in the Pacific, extending from the west coast of Mexico to Hawaii.
  • On the average, one square metre in the Clarion-Clipperton Zone contains around 15 kilograms of manganese nodules.
  • The occurrences in the Clarion-Clipperton Zone (CCZ) alone hold around 10 times more manganese than the economically minable deposits on land today.

Peru Basin:

  1. The Peru Basin lies about 3000 kilometres off the Peruvian coast.
  2. It is about half as large as the Clarion-Clipperton Zone.
  3. The region contains an average of 10 kilograms of manganese nodules per square metre.

Penrhyn Basin:

  1. This also lies in the Pacific and is near the Cook Islands, a few thousand kilometres east of Australia.
  2. It has an area of around 750,000 square kilometres.
  3. The region contains an average of 25 kilograms of manganese nodules per square metre of sea floor.

Indian Ocean:

  1. So far only a single large area of manganese nodules has been discovered here, with an area comparable to that of the Penrhyn Basin.
  2. It is located in the central Indian Ocean.
  3. Each square metre of the sea floor here contains around 5 kilograms of manganese nodules.
  4. The International Seabed Authority (ISA), an autonomous international organisation established under the 1982 United Nations Convention on the Law of the Sea, allots the ‘area’ for deep-sea mining.
  5. India was the first country to receive the status of a ‘Pioneer Investor ‘ in 1987 and was given an area of about 1.5 lakh sq km in the Central Indian Ocean Basin (CIOB) for nodule exploration.
  6. In 2002, India signed a contract with the ISA and after complete resource analysis of the seabed 50% was surrendered and the country retained an area of 75,000 sq km.

Associated Ecosystems

  • The nodules provide a substrate for a wide variety of suspension feeders and specialised nodule epi- and in-fauna, which are dependent on the hard substrate provided by the nodules.

Who owns resources in the sea?

  1. The international Law of the Sea precisely regulates who can mine manganese nodules or massive sulphide and cobalt crusts in the future.
  2. If the resources are located within the Exclusive Economic Zone (EEZ) of a country, the so-called 200 nautical mile zone, this country has the sole right to mine them or to award mining licences to foreign companies.
  3. This is the case, for example, in a part of the Penrhyn Basin near the Cook Islands.
  4. The CCZ, the Peru Basin, and the Indian Ocean area, on the other hand, all lie far outside the Exclusive Economic Zones, in the realm of the high seas.
  5. Here, mining is centrally regulated by an agency of the United Nations, the International Seabed Authority (ISA), with headquarters in Kingston, Jamaica.
  6. In particular, the ISA ensures that the benefits from future activities related to marine mining are shared equitably and exclusive access to the promising resources in the deep sea by rich countries should be prevented.
  7. Its authority is based on various articles of the United Nations Convention on the Law of the Sea, which define the high seas as the common heritage of mankind.
  8. For the manganese nodule areas this means that contractors apply to the ISA for an exploration area of up to 150,000 square kilometres.
  9. The individual contractor must pay a licence fee for these areas.
  10. The crucial condition is that the countries can only use half of their licence area, or a maximum of 75,000 square kilometres.
  11. After preliminary exploration, the other half is reserved for developing states.
  12. So far the ISA has awarded 12 licences for the Clarion-Clipperton Zone and one for the Indian Ocean, all to various states.

Extraction

  • There are Two Major Hurdles:
  1. cheap availability of metals from more easily accessible land-based deposits.
  2. presence of numerous volcanic hills with a relief of about 100m which make the extraction of nodules extremely patchy.

The United Nations Convention on the Law of the Sea (UNCLOS)

  • It is an international treaty which was adopted and signed in 1982.
  • The Convention has created three new institutions on the international scene:
  1. The International Tribunal for the Law of the Sea,
  2. The International Seabed Authority,
  3. The Commission on the Limits of the Continental Shelf.
  • It is an initiative of the Ministry of Earth Sciences to explore seabed resources and to improve India’s position in ocean research field.
  • India’s exclusive rights to explore polymetallic nodules from seabed in Central Indian Ocean Basin (CIOB) were extended by further five years in 2017.
  • These rights are over 75000 sq. km of area in international waters allocated by International Seabed Authority for developmental activities for polymetallic nodules.
  • India is the first country to have received the status of a pioneer investor in 1987 and was allocated an exclusive area in Central Indian Ocean Basin by United Nations (UN) for exploration and utilization of nodules.
  • International Seabed Authority (ISA) is a UN body set up to regulate the exploration and exploitation of marine non-living resources of oceans in international waters.

Polymetallic Nodules

  • Of all the mineral resources considered as potential targets for deep-sea mining, polymetallic nodules (also commonly called manganese nodules) are probably the most likely commodity to be developed into a commercial operation.

Formation

  • Polymetallic nodules are rounded accretions of manganese and iron hydroxides that cover vast areas of the seafloor, but are most abundant on abyssal plains at water depths of 4000-6500 metres.
  • They range in size from a few millimeters to tens of centimeters.
  • Growth of these nodules is extremely slow, at a rate of millimetres per million years, and they remain on the seafloor surface, often partially buried in a thin layer of sediment.

Composition

  • The composition of nodules varies with their environment of formation, but in addition to manganese and iron, they can contain nickel, copper and cobalt in commercially attractive concentrations as well as traces of other valuable metals such as molybdenum, zirconium and Rare Earth Elements.

Distribution

  • The nodules of greatest commercial interest occur in the Clarion-Clipperton Zone in the equatorial Pacific Ocean (CCZ) and in the Central Indian Ocean Basin.

Associated Ecosystems

  • The nodules provide a substrate for a wide variety of suspension feeders and specialised nodule epi- and infauna, which are dependent on the hard substrate provided by the nodules.

Extraction

  • The concept of polymetallic nodules as a serious commercial prospect emerged in the 1960’s and 70’s, leading to a rush to develop the technology to extract them.
  • However, the industry never developed due to the cheap availability of nickel from more easily accessible land-based deposits.
  • For current mining scenarios, the mining process is predicted to disturb about 120 km2 of seabed per year per mining operation and represents a major environmental impact.
  • However, owing to the presence of numerous volcanic hills with a relief of about 100m the extraction of nodules will be extremely patchy.

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