Ocean as a resource by kakali

OCEAN AS A RESOURCE

OR ANTHROPOGENIC USE OF OCEANS

BY KAKALI ROY

DEPARTMENT OF M.SC.GEOGRAPHY

ADAMAS UNNIVERSITY

An ocean is a body of saline water that composes much of a planet's hydrosphere. 

On Earth, an ocean is one of the major conventional divisions of the World Ocean, which covers almost 71% of its surface. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, and Arctic Oceans.

The oceans comprise about 1457,000,000 cubic k.m of water that is about 97.2 % of the world’s total water resources .

The oceans have always been a vast reservoir of resources but in recent times the exponential growth of population and the outstripping of resources of land have drawn more attention towards the oceans.

OCEAN

A resource is anything that is used to satisfy human needs. Typically resources are materials, energy, services, staff, knowledge, or other assets that are transformed to produce benefit and in the process may be consumed or made unavailable.

From a human perspective a natural resource is anything obtained

from the environment to satisfy human needs and wants.From a broader biological or ecological perspective a resource satisfies the needs of a living organism

There are four major type of resource we can get from marine: Fresh Water Resources, Marine Mineral Resources, Marine Energy Resources, Marine Food Resources.

TYPES OF MARINE RESOURCES

The water of ocean is neither fit for human use not for the agricultural purpose but with the input of technology the saline water can be converted into fresh water. This coversioun can be done through desalination.

Desalination is a process of obtaining fresh wayer from salt water. There are several possible desalinization methods – Flash Desalinization , Electrodialysis,Reverse Osmosis,freezing And Salt Absorbtion.

FRESH WATER RESOURCES

Marine resources are found either dissolve in the seawater or they can be fond as deposited – either on the surface or below the surface.

Marine Mineral Resources

Each cubic mile of seawater contains about 165 million tons of solids making the 350 million cubic miles of seawater the world's largest continuous ore body.

Sodium and chlorine are the most abundant accounting for 85 % of the sea’s dissolved salt.

Magnesium and Bromine are other important chemicals elements of sea.

Minerals of value are Gold , Silver ,Zinc , Uranium And Thorium. It is also estimated that ocean as a whole contains about 6 mmt of gold deposits.

Throughout the world , a ton of seawater contains about 60mg of gold.

MINERALS DISSOLVED IN SEAWATER

The surface deposit consist of the deposits found on the continental shelf and slope.

1.Continental Shelf and Slope deposits- The deposits found on the continental shelf and

slope region are found mixed with sand containing CALCIUM CARBONATE, IRON, URANIUM, GOLD, DIAMOND, PLATINUM, etc.

Surface Deposits

Source :http://subseaworldnews.com/wp-content/uploads/2014/03/NOC-

Receives-Grant-to-Explore-Deep-Ocean-Floor-for-Minerals.jpg

Zircon, Monazite And Utile - are found along the west cost of India, coastal Brazil, Australia , New Zealand , SriLanka And The USA. India possesses 90% of the world’s monazite reserves in Kerala’s places deposit.

Rutile a beach placer deposit is found along the eastern and western coast of Australia which supplies 29%of these deposits.

Magnetite- occurs in those areas where volcanic rock materials are deposited. Such formations are found along the western coastal belts of N America and east coast of Asia in Japan . The reserve of iron rich sediments in Japan is estimated to be 36 million tons.

Cassiterite- an important tin ore is a residual mineral of the weathering of granites. A belts Stretches for 3000km from northern Thailand and western Malaysia to Indonesia.

Gold Placer- are found to occur along the coast of Alaska on shelf zone of east pacific and in river delta sediments along Oregon, Chile, South Africa And Australia.

Diamonds- like gold is found in the sediments washed down the river in some areas of Africa and Australia. It is found mixes with sand in a belt running thousand's of k.m away from the southwest African coast.

Plutinum – along with sand is found in parts of the united states, Australia and south Africa.

Phosphorite- which can be to produce phosphates needed for fertilizers is found in shallow waters as phosphorites mud's and sands. It can be also found in the forms of nodules on the continental shelf and slopes.

30 % phosphate and largest deposit are known to exist off Florida. California, Mexico, Peru, Australia, and north western ands southern Africa. The worlds ocean resave of phosphrite is estimated at about 50 million tons.

Sulphur- needed for industrial use , is known to exist in The Gulf Of Mexico and the Mediterian sea where the reserves are to the tune of million tons.

Sands- are mined as a source of calcium carbonate throughout the Bahamas Island , which has an estimated reserve of 100 billion metric tons.

Many countries have in fact been extracting sand and gravel for decades. This loose rock is used to make concrete, as backfill on building sites and in harbours, and also as beach nourishment to protect coastlines.

According to estimates published by the International Council for the Exploration of the Sea ( ICES), the organization responsible for the North Atlantic marine habitat, 93.5 million cubic meters of sand were removed from European water s in 2012.

USA uses only about 57 million cubic metres of marine sand each year.

Europe’s second largest consumer of marine sand after the Netherlands is Great Britain. That nation used almost 12 million cubic metres in 2011, plus nearly 7 million cubic metres of gravel

A suction dredger extracts sand from the North Sea floor off the Dutch island of Ameland to widen the beach.

The sand-water combination is pumped from the ship onto the beach using the “rainbow method”.

Palm Jumeirah

Deep Sea Deposits – In the deep sea areas two main types of mineral deposits are important .these are the manganese nodules and metalliferous sediments.

Manganese Nodules - Manganese Nodules are the most abundant in the deepest part of the oceans other than the trench region.

Manganese nodules are hydrogenous pelagic deposits found scattered across the world’s deep ocean floors with particular concentration in the red clay regions of northeast Pacific .

The nodules were discovered by the Challenger Expedition (1873- 1867) and in the last 25 years have been the focus of intense research and development of mining and extraction techniques by large mining corporations and multinational consortia.

Polymetallic nodules, also called manganese nodules. These are Most valuable deep sea mineral resources at present . This is because They occur as unconsolidated deposits at the sediment surface and they contain concentrations of valuable metals such as nickel , copper ,lead and zinc, all precipitated from seawater.

Those of greatest economic interest contain manganese (27-30%), nickel (1.25-1.5 %), copper (1-1.4 %) and cobalt (0.2-0.25 %). Other constituents include iron (6%), silicon (5%) and aluminium (3%), with lesser amounts of calcium, sodium, magnesium, potassium, titaniumand barium, along with hydrogen and oxygen.

Nodule growth is one of the slowest of all known geological phenomena, on the order of a centimeter over several million years. 

Several processes are hypothesized to be involved in the formation of nodules, including the precipitation of metals from seawater (hydrogenous), the remobilization of manganese in the water column (diagenetic), the derivation of metals from hot springs associated with volcanic activity(hydrothermal), the decomposition of basaltic debris by seawater (halmyrolitic) and the precipitation of metal hydroxides through the activity of microorganisms (biogenic).

Source:http://worldoceanreview.com/en/files/2014/05/wor3_c2c_fig_2-19.jpg

The most important of the subsurface deposits are oil and natural gas.

These two deposits represent 90% of the mineral value presently taken from the sea.

The sub surface deposits are mostly found on the continental shelves where the conditions for the availability of petroleum are conductive.

Salt dome’s where petroleum and natural gas is trapped in the uplifted and fractured rocks around the dome.

The major offshore oilfields are found in the Gulf Of Mexico, The Persian Gulf, the North Sea And Off The Northern Coast Of Austrelia,the Southern Coast Of California And The Coasts Of Arctic Ocean .

SUB SURFACE DEPOSITES

Source:http://www.bbc.co.uk/nol/shared/spl/hi/world/10/oil_day/feature_include_total_oil_fields/img/world_oil_786.gif

There are still many areas of the world that are relatively unexplored in terms of oil and gas those are The Continental Shelves Of East Asia, South Asia Around Sumatra And Borneo In Indoneshia, East Africa, North West Africa, Parts Of South America And Antartica .

New discoveries have been made near the Philippines and off the mouth of the Amazon river.

IMPORTANCE OF OIL IN

HUMAN LIFE VIDEO

Sulpher- In addition to petroleum , salt domes are rich sources of Sulpher.

Sulpher accumulates around the salt plug because an insoluble sulpher containing a compound anhydrite (CaSO4),is generally present in original salt deposits.

Sulpher is found off the coast of Thailand at 25m deep under ocean.

Coal- Coal is the byproduct of decomposition of thick lush tropical vegetation and is therefore found on the land surface . But changes in the sea level and land geography over geologic time have caused some coal deposits to become submerged.

These submerged coal deposits are found in Japan, the UK, Africa and off Mumbai in India.

In Japan undersea coal deposits are reached by shafts that stretch under the sea from the land or descends from artificial islands.

Various renewable energy resources have their source in the marine waters. The sea is , thus, an inexhaustible source of energy .

DEUTORIUM- Deutorium is an isotope of hydrogen. It is the most important raw material for the fusion process. The oceans contain 25 trillion tones of it . If ever the mankind was to generate energy from fusion of deutorium and titanium the seawater would be provide an inexhaustible source of deutorium.

OTEC- OTEC stands for Ocean Thermal Energy Conversion. OTEC system are also called sspps or solar sea power plants . OTEC relies on the natural temperature difference between the warm surface and the cold surface and the cold deep waters of the sea. Surface waters heated by the sun , easily reaches more than 25˚C in Tropical ares , wheres deeper waters ,cooled by polar currents have a tepmerature of barely afew degrees .this difference of about 20˚C is enough to produce electricity.

MARINE ENERGY RESOUCES

OTEC

Osmotic Pressure- Energy can be produced by exploiting the difference in salt content between two bodies of water, for example where fresh water of the rivers and streams flows into estuaries .

Under such circumstances when fresh water is separated from the salt water by a semi permeable membrane then the water molecules will be drawn through this membrane to the saltier side will rise until the pressure on the salt water side.

Consequently the water level on the salty side will rise until the pressure on the salt water is equivalent to a column of water 240 m in height and increased pressure stops flow of molecules through membrane.

This difference could be used to produce electricity by passing the water under pressure through a turbine . The rate at which energy could be extracted from this source is quite large.

Tidal Energy- The rise and fall of tides can be used to generate electricity . Favorable conditions for the generation of tidal energy are found in coastal areas with a large tidal range or in narrow channels with swift tidal currents.

There are thus, certain places in the world where conditions conductive for generations of electricity by tide exist. The largest tidal ranges in the ocean are around 15 m, for example in the bay of Fundy, Nova Scotia.

There are two ways by which energy can be generated by the rise and fall of tides . Both require buildings a dam across a bay or an estuary, So that seawater can be held in the bay at high tide .

As the tidal water comes in, the dam closed until a substantial hydraulic lead is established between the ocean and the lower water in the estuary.

At the point the gates are opened and water flows through the turbines into the estuary thus, Producing electricity.

As the tide goes out , it again produces a hydraulic lead. At this time the gates are closed. The estuary by this this time has filled and dammed water in the estuary is released through gates which runs turbines producing electricity.

This system requires very specialized turbines system that must be able to generate energy on both the flood and edd tide.

actual electricity generating facilities exist at the RANCE river installation in France and a small pilot plant at the Kislaya Guba In Murmansk In The Commonwealth Of Interdependent States.

India has also build a pilot power plant at Kandala. It is the first such facility in Asia.

Current Energy – The massive ocean surface currents of the world are untapped reservoirs of energy. Their total energy flux has been estimated at 2.8 x 10₁₄ ( 280 trillion) watt hours. Even though the currents have low energy densities the kinetic energy in major currents is quite impressive.

The Gulf Stream, for example , Channels 30x 106 m3 of water per second at a surface speed of more than 4 km/h. This flow can give 10,000 MW or 87.6 billion annual kilowatt hours theoretically.

These systems have in common in that they would be difficult to build and maintain.

Moreover most of the wind driven oceanic current generally move slowly and are found too far from where the power is needed.

Cost is also very high.

Wave Energy- A tremendous amount of energy exist in waves. The power present in waves is estimated at 2.7x 1012 watts. This energy is however, quite dispersed and is not constant at any given location or time. Therefore, it is very difficult to tap this energy.

Biomass Conversion- The biomass conversion method is based on extraction of energy from the sea, by converting photo synthetically produced organic matter or biomass into fuel.

The oceans fix some 10 10 or more tone of carbon per year into organic material and some of it rather efficiently in large marine plants such as KELP.

The biomass conversion method relies on the growing of such plants for anaerobic decomposition with the ultimate production of gas. The gases produced , usually a mixture of carbon dioxide and methane, have heating values of 500-800 btus per standard cubic feet and can be readily upgraded to pipeline quality gas by established producers.

MARINE FOOD

RESOURCES

Oceans have become major source of food and their importance is likely to increase in the near future.

Because of the sheer size , the oceans in general will have a larger food potential. Since the population is also increasing, very little options are lest for the expansion of agricultural land on the surface.

So oceans have assumed added significance. In addition, the ocean food resources are nutritionally of a very high quality .

They have amino acids in the correct ratio for human use.

They are a better source of Vitamin B-12. They are low in cholestrol and saturated fats. They are high in polyunsaturated fats and the

essential fatty acids.

MARINE FOOD RESOURCES

In the USA alone, fishing supports an industry worth nearly $50 billion annually.

The importance of seafood in the human diet varies greatly around the world. In the United States, consumption is roughly 7 kilograms (about 15 pounds) per person per year.

That amount is small compared with various other nations. The Japanese, for example, rely heavily on seafood for their animal protein. Seafood consumption, per individual, is at least five times higher in Japan than in the United States.

Terrestrial animals, such as beef and pork, are more expensive than seafood in Japan; consequently, that country has a fishing fleet that travels far and wide. The Japanese also purchase seafood from other nations and have a highly developed aquaculture industry.

source :http://cdn2.vox-cdn.com/uploads/chorus_asset/file/664154/0315-fishingyields-EN.0.jpg

The term "seafood" commonly is used to describe aquatic plants and animals consumed by humans, regardless of source.

Fisheries and aquaculture produce roughly 140 million tons of plants and animals annually.

Included are finfish, mollusks (including octopus and squid), crustaceans , seaweeds, reptiles, and marine mammals: the first four categories make up the bulk of the human food that comes from the waters of the world.

The seaweed plantation in Bali, Indonesia illustrates the role of mariculture (marine aquaculture) in meeting human food demands. Global seaweed production exceeds 10 million metric tons annually.

Clam and oysters dominate the mollusk category, followed by scallops, mussels, and abalone. Total mollusk production exceeds 15 million metric tons annually.

Kelp- Kelps are large seaweeds (algae) belonging to the brown algae (Phaeophyceae) in the order Laminariales. There are about 30 different genera.

The organisms require nutrient-rich water with temperatures between 6 and 14 °C (43 and 57 °F). They are known for their high growth rate — the genera Macrocystis and Nereocystis can grow as fast as half a metre a day, ultimately reaching 30 to 80 metres.

Bongo kelp ash is rich in iodine and alkali. In great amount, kelp ash can be used in soap and glass production.

 Alginate, a kelp-derived carbohydrate, is used to thicken products such as ice cream, jelly, salad dressing, and toothpaste, as well as an ingredient in exotic dog food and in manufactured goods.

Biomedical products- Many benthic organisms contain biologically active compounds that have potential practical use.

Extracts of certain sponges yield anti –inflammatory and antibiotic substance an anticoagulant has been extracted from red algae, and the antibiotic substance , acrylic acid, has been extracted from other sea weeds.

Some corals produce antimicrobial compounds , and the sea anemone. An thopleura, which provides cardiac stimulant.

A muscle relaxant has been isolated from the snail Murex.

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