Aviation

Last Update: May 2023 (Aviation)

Aviation

This article deals with ‘Aviation – UPSC.’ This is part of our series on ‘Economics’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here.


Introduction

  • India’s domestic passengers have almost doubled in the last 5 years owing to the UDAN scheme
  • In 2020, the number of airports in India reached the 100 mark.


Potential of Civil Aviation Sector

  • The geographical, economic and demographic conditions are such that India can be on the third-largest number of airline passengers. These favourable conditions are listed below.
    • India’s geographical situation in the middle of the Eastern and Western Hemisphere
    • India has a robust middle class of about 35 cr Indians. 
    • Rising income due to India being one of the fastest-growing economies globally
    • High tourism potential
  • But strict and outdated regulations have not allowed the sector to achieve its potential, and India is ranked 10th globally wrt the number of airline passengers. 

Aviation Challenges

Aviation

1. Infrastructure constraints

  • The civil aviation infrastructure, especially in the metros such as Delhi, Mumbai etc., has been operating at saturated levels. Therefore, the government will have to attract large investments in building new and upgrading the existing infrastructure.

2. Aviation Turbine Fuel (ATF)

  • The taxation on Aviation Turbine Fuel (ATF) in India is high. Hence, ATF is priced 60% higher in India compared to the global average. Given the fact that ATF accounts for 40% of the operating costs of airlines, it puts Indian airlines under considerable pressure.

3. Lack of Skilled Workers

  • Given the growth of the aviation sector, India will need 0.25 skilled workers in the aviation sector over the next decade.

4. Limited Capacity of Airlines

  • 90% of traffic is concentrated in the metro cities. Although the potential consumer base is large, airlines have not been able to tap it.

5. Predatory Pricing

  • Indian airlines indulge in Predatory pricing, i.e. sell their tickets at very low prices to bleed the competitors out of business. But in the process, they bleed themselves and make substantial losses.

6. Aviation Safety

  • In India, there were 440 aviation safety violations in 2016 and 340 in 2017, which are quite high compared to global standards.

7. Other challenges

  • High Airport Charges
  • High aircraft to man ratio

Airlines in India

Public Sector Air India and its subsidiaries (No Public Sector Airline after Privatization of Indian Airlines)
Private Sector Air India = owned by Tata GroupB
Jet Airways = Naresh Goyal
Spicejet = Sun group (of Kalanidhi Maran)
Interglobe Aviation (IndiGo)
Go Airlines
Cargo Airlines Deccan cargo (Deccan 360) 
Blue Aviation Express Logistics

New players in the Indian market

  • Air Asia (Tata 30%+ Malaysian Airline AirAsia 49% + Telstra 21%)
  • Air Costa
  • Quickjet Cargo Airlines

Air India

  • Air India was formed after Air India & Indian Airlines merger in 2007. 
  • It has the largest fleet in India, including new planes. It controls 17% of the Indian Market.
  • But it suffered from a debt of over ₹50,000 Crore. Hence, the government wanted to privatize it. After large discussions, the Tata group has bought the airlines. 

Pawan Hans Helicopter ltd

  • It is a government-owned company started in 1985 
  • Provides helicopter service to
    • ONGC’s offshore drilling platforms
    • Hilly and inaccessible areas
    • Amarnath Yatra
    • Emergency evacuation

Disinvestment of Air India

Timeline of Air India

1932 Tata Airlines begins offering air services in India
1946 Tata Airlines renamed as Air India (AI)
1953 Air Corporation Act passed, and Air India was nationalized along with 7 other private carriers.
1981 Vayudoot, a new carrier, established to act as a regional feeder airline
1986 To boost tourism, private air taxis were allowed to fly with riders.
1993 After suffering an annual loss of ₹200 crores, Vayudoot was merged with Indian Airlines, adding to its debt load.
1994 The Air Corporation Act was repealed, and private carriers were allowed to enter the market again.
2003 Naresh Chandra Committee report calls for the privatization of Indian Airlines and Air India but faces stiff opposition.
2005 Air India signs a purchase agreement for 50 Boeing aircraft at the cost of ₹ 33,000 crores.
2007 Indian Airlines & Air India were merged to form the National Aviation Company of India Ltd.
2010 The company was renamed Air India
2011 CAG hauls up Air India and Civil Aviation Ministry for reckless purchase of aircrafts
2017 Air India losses mounted to ₹ 50,000 crores forcing the government to move towards privatization.
2021 Tata group bought Indian Airlines from the Government of India.

Debt Causes

Air India has a debt of ₹ 50,000 crores, accumulated for various reasons spanning decades. CAG Report of 2011 too has given detailed reasons for this 

  1. Unprofessionalism in management when compared to world-class airlines. 
  2. Massive fleet expansion 
  3. Free travels by VVIPs like Ministers and Officials
  4. In early 2005, Indian Airlines inducted planes despite no demand for them. These were funded by raising high-interest loans.  
  5. Liberalized policy on international routes like nonstop flights to the US was loss-making.

Pros of disinvestment of Air India

  • Indian Airlines is loss-making. Hence, keeping it afloat under government control would be wasting taxpayers’ money 
  • The private sector has taken up, and private airlines already cater to over 85% of the air travel demand in the country.
  • It would bring professionalism in management.  
  • Government money that keeps Air India afloat would be better used to fund important social and infrastructure programs. 
  • It will help the government to spend its energy on core governance issues. 
  • The sale of Pawan Hans in 2016 revived the company owing to the infusion of professionalism and better management.

Cons of disinvestment of Air India

  • Many sectors and routes that private airlines may not find economical to operate are handled by Air India. E.g., Private Airlines give limited services to North East. 
  • Air India, which is a sovereign airline, is used by Government in emergency evacuations of Indian nationals from warzones.  

National Civil Aviation Policy, 2016

Key highlights of  Aviation Policy-2016 are as follows

1. 5/20 rule Scrapped

  • 5/20 rule, i.e. 5 years of operation and a fleet of 20 aircraft before handling international flights, has been scrapped. 
  • But airlines will have to operate at least 20 aeroplanes or 20% of their planes (whichever is higher) on domestic routes. 

2. Improve Air connectivity to smaller cities 

  • The policy wants to improve air connectivity with smaller cities. 

3. Subsidized Tickets

  • Under the regional connectivity scheme, the maximum price that can be charged is Rs 2500 per hour.
  • A 2% levy is to be charged on all domestic and overseas tickets to subsidize airlines’ losses.

4. Infrastructure

  • Airports in Tier 2 and 3 cities will be operationalized on the ‘No Frills Model’. 

5. Open Skies Policy

  • Under the ‘Open Skies Policy’, foreign airlines can operate unrestricted and unlimited flights in and out of India. It will help India become a regional hub like Dubai and Hong Kong. 

6. Other important

  • Maintenance, Repair & Overhaul (MRO) don’t have to pay a royalty to airports where they operate, which will help make India an MRO hub. Royalty is up to 20% presently.  

Side Topic: No Frills Airport

  • No Frill Airports are the airports with lesser facilities like no escalators, no AC Lounges etc.
  • These Airports are made in small cities because airports providing high-end facilities are not feasible in Tier II & III Cities.
No Frills Airport

UDAN Scheme

Timeline

2017 Aviation Ministry announced a scheme named UDAN (Ude Desh ka Aam Naagrik) to increase air traffic to Tier II & Tier III cities. 
2018 Second phase of UDAN scheme announced.
2019 UDAN (International) scheme launched, under which Guwahati Airport will be connected to Bangkok and Dhaka shortly. 

Under Scheme

  • Capping the fare
    1. Airfare for an hour’s journey of about 500km is capped at ₹2,500. 
    2. In the case of helicopter operations, fares are capped at ₹2,500 for a 30-minute flight.
    3. Seaplanes have also been included in the scheme in the subsequent phases. 
  • Capping of airfare is applicable on half of the flight’s seats.
  • Centre provides subsidy support to airlines via a Viability Gap Fund (VGF), which obtains money by levying cess on non-regional routes. 
  • Airlines get three-year exclusive rights to operate regional flights. 
  • No airport charges for airlines as airline operators complain that airport expenses constitute 25% to 30% of operating costs.
  • The scheme will be operational for a period of 10 years. 

Importance

  • The scheme has brought Tier 2 and Tier 3 cities into the country’s aviation network. 
  • Positive Spillover Effect on Economy: The scheme will make businesses and trade more efficient, enable medical services and promote tourism.
  • Employment Generation: As per the International Civil Aviation Organisation, each job created in the aviation sector creates 6.1 jobs in the economy. 
  • This scheme can help in improving the health of the ailing Aviation Sector. Even if 1 middle-class family buy 1 air trip per year, the Aviation sector can sell 35 crore tickets. 

Issues

  • Misdirection of Subsidy 
    • Even without the subsidy, there was an increase in air flyers.  
    • The subsidy is given to Middle Class when it could better serve some Social Schemes aimed at Lower Class.
  • Against Laisse – Faire: Airlines are given exclusive rights for 3 years, and other airlines cant operate there even if they want to. 
  • Another levy for creating the Viability Gap Fund will impact the already overtaxed Aviation Sector. Taxes on ATF is already among the highest in the world.

NABH (Nextgen Airports for Bharat) Nirman initiative

Aim: Capacity augmentation of the airport because 25 busiest airports of India are operating beyond their capacity.  

What it will do?

  • Expansion of the airport capacity to handle a billion trips a year.  
  • Establish about 100 new airports in the next 15 years at an estimated Rs 4 lakh crore investment. 
  • Increase the economic and tourism activities in the smaller cities by connecting them with airline services.

FDI in Aviation

FDI in Aviation

Bodies related to Aviation Sector

Ministry of Civil Aviation

  • Ministry of Civil Aviation mainly looks after the Aviation sector in India 

Airport Authority of India

  • AAI is a PSU of Miniratna category. 
  • Sovereign Air traffic controller of India.
  • It manages international airports, domestic airports, and custom airports.

Directorate General of Civil Aviation (DGCA)

  • DGCA is the regulatory body of Civil Aviation. 
  • Its functions include 
    • Registrar of civil aircrafts
    • Laying down airworthiness requirement 
    • Gives license to pilots
    • Investigates of minor accidents 
    • Implements Chicago Convention

Bureau of Civil Aviation Security (BCAS)

  • Initially, it was a cell in DGCA setup in 1976 on the recommendation of the Pandey Committee after an aircraft hijack in 1976. It has been restructured now an independent department under the Ministry of civil aviation, after Kanishka Tragedy in 1985
  • BCAS is the regulator of the security of civil aviation. 
  • Under Aircraft Security Rules, 2022, BCAS can impose penalties of up to ₹1 crore on airports and airlines for violation of security measures. 

International Civil Aviation Organization (ICAO)

  • ICAO is a specialized agency of the UN and was set up under the provisions of the Chicago Convention of 1944.
  • It is headquartered in Montreal, Canada and India is a member of ICAO since its inception.
  • ICAO ensures the operation of airlines between different countries.

Railways

Last Update: May 2023 (Railways)

Railways

This article deals with ‘Railways – UPSC.’ This is part of our series on ‘Economics’ which is an important pillar of the GS-3 syllabus. For more articles, you can click here.


General Information

Timeline

1853 First Train started in India (from  Mumbai to Thane (34kms))
1924-25 Rail budget was separated from general budget (based on the Acworth Committee Report of 1921)
2015 Bibek Debroy Committee on railway restructuring gave recommendations.
2016 India’s first Railway University opened in Vadodara, Gujarat
2017 Railway Budget was merged with General Budget.

Share of Railways in the transportation of goods

In the US, 44% of goods are transported through railways, but in India share has been decreasing each passing year  (65% in 1970, 30% in 2007 & 25% in 2020)

Railways

Benefit of Railways wrt other modes of transport

  • Cheaper: The transportation cost of goods using railways is low (₹2/ton/km).
  • Low Carbon Footprint: Railways are a greener mode of transportation as they consume 20% less energy.
  • Integrate India with world markets: Railways can help to expand & integrate markets as they did in Europe and the USA. 
  • Spur economic activity: According to Economic Survey, 1 rupee invested in the railways increases GDP output by 5 rupees.

Railway gauge size

Gauge Size
Broad 1,676 mm
British used it to send raw material from Indian hinterland to port cities
Meter 1,000 mm 
Narrow 762 mm
Lift  610mm
  • Ranking track length in India: broad > meter > narrow
  • Under the Project uni-gauge, Railways has converted selected routes into broad gauge.

Railway Undertakings

Indian Railway has 14 undertakings. Important ones are 

  • IRCTC (provides catering services)
  • CONCOR (Container Corporation of India)
  • Railtel

Statistics about Indian Railways

Statistics about Indian Railways
Operational Ratio of Indian Railways

UNESCO World Heritage: Indian railways

  1. Darjeeling Himalayan Railways
  2. Nilgiri Mountain Railways
  3. Kalka Simla Railway
  4. Chhatrapati Shivaji Terminus (Victoria Terminus) (It was designed by British architect FW Stevens in  Gothic Style)

National Rail Plan for India, 2030

Under this plan, the government of India wants to achieve the following

  1. Increase Indian railway’s share in freight transportation to 45% and average speed of freight transportation to 50% by 2030.
  2. Achieve 100% electrification of all train routes.
  3. Increase the speed of Delhi-Howrah and Delhi-Mumbai routes to 160 km/hr.
  4. Identify and develop new Dedicated Freight Corridors and High-Speed Rail Corridors.
  5. Improve the safety of railway tracks in India.

Railway Budget merged with General Budget

Railway Budget vs General Budget

  • 1924-25: British separated rail budget based on the recommendations of Acworth Committee (1921).
  • Indian constitution didn’t provide for a separate railway budget or budget in parts. But Parliamentary rules of procedure permitted it.
  • 2017: Railway Budget was merged with General Budget.

Arguments for merging Railway Budget with General Budget

  1. Economic Reasons:
    • Saving funds of financially starved Railways: Indian Railways need not pay the annual dividend of ₹10,000 crores to the Government. 
    • Railways will be better equipped to raise funds on the strength of the sovereign instead of being restricted to the Indian Railway Finance Corporation.
  2. The situation is different from 1924:  In 1924, the railway’s expenditure was more than the expenditure of all other administrative expenses. It has presently reduced to just 6% of total government spending.
  3. Any other country does not follow this system. 
  4. Politicization of Railways: This provision was used by politicians for populist reasons.   
  5. Bibek Debroy Committee too has suggested separating the railway budget from the general budget.

Why should there be a separate budget for the Railways?

  1. Indian Railways is different from other central ministries due to its size and scope. Whereas other ministries just spend, Railways is an operational ministry as it earns and spends. 
  2. Bibek Debroy Committee has recommended separating the railway budget from the general budget. But it wasn’t a standalone measure.

Metros / Mass Rapid Transit System (MRTS)

  • Rapid transit, also known as the metro or subway, is high-capacity public transport. Unlike buses & trams, they are electric & operate on an exclusive right-of-way. 
  • First Metros was started in Kolkata in 1984 from Dum Dum to Tollygunge. 

Benefits

  1. Reduced traffic density on the roads
  2. Reduced vehicular emission leading to decreased air pollution
  3. Reduced fatalities due to road accidents
  4. Reliable & safer journey
  5. Decreased fuel consumption
  6. Decreased vehicular operating cost

Metro Rail Policy, 2017

Metro Rail Policy, 2017

Indian Government has announced its Metro Rail Policy with PPP as the centre of the scheme

  • PPP is the centre of the scheme. The PPP component has been made mandatory for availing assistance from the central government.
  • The new policy mandates Transit Oriented Development (TOD).
  • Power to set up Fare Fixation Authorities has been vested with states. 
  • States can raise low-cost debt capital through the issuance of corporate bonds. 
  • Empowers state to charge a “betterment levy” in areas that will benefit from the metro rail projects. 

Problem with the Policy

  • The main problem is with the PPP model. PPP model has failed in Delhi Metro’s airport line — and is faltering in the Mumbai and Hyderabad metro rail projects. Due to various positive externalities of Metro, these projects must be subsidized by the government. In  Delhi Metro, the Centre and state government have footed much of the bills. Even E Sreedharan has opined that the PPP model is not suitable for Metros as private players expect more than 12% return from metro projects while no metro project can yield more than 3 per cent.

MetroLite or MetroNeo

  • MetroLite or MetroNeo is the model for Metros in smaller cities such as Nashville in the USA and Indian cities of Jammu, Coimbatore, Srinagar etc.
  • It was announced in the budget of 2021. 
  • These are a lighter version of conventional metro rail and can be set up at a lesser cost (2/3rd to 1/3rd cost of the normal metro).

Issues that Indian Railways is facing

1. Cross Subsidisation

  • Railways keep passenger tickets low –> Indian Railways suffer the loss of 23 paisa/passenger/km.
  • To compensate for the loss, Indian Railways keep freight prices higher.

2. Operating ratio of Indian Railways

  • The Operating Ratio of Indian Railways is just 98.4%, i.e. Indian Railways spend 98.4 rupees out of 100 rupees earned. Hence, only 1.6 rupees are left in surplus. 
  • It is a problem because Indian Railways left with no capital for expansion. 

3. Rail Safety / Large accidents

  • A large number of rail accidents such as derailments and collisions take place in India.

4. Congestion of Tracks

  • Indian railways has an overstretched  infrastructure  with 60 per cent plus routes being more than 100 per cent utilized,  leading to a reduction in the average speed of passenger and freight trains

5. Organisational Structure

  • Due to complex and outdated organizational structure, project approval and completion take extraordinarily long.

Steps already taken to improve railways

  • Tariff rationalization of fares has already been completed.
  • Indian Railways is focussing on Non-Tariff Earnings such as advertisement revenue.
  • Rail Budget has been merged with General Budget. 
  • The government has constituted the Rail Development Authority (RDA).
  • New delivery models like Roll-on Roll-off (Ro-Ro)services have been started.
  • Indian Railways have changed the accounting system  to Accrual Based Accounting from Cash Based Accounting 
  • Indian Railway Finance Corporation has issued Masala Bonds to gather funds.
  • Kayakalap Council under the Chairmanship of Ratan Tata has been constituted

Side Topic: Accrual Based Accounting

Accrual Based Revenues are reported on Income Statement when they are earned
Cash Based Revenues are reported on Income Statement when they are received

Non-Tariff Earning

  • Indian Railways has decided to increase its focus on non-tariff earning
  • All the budgets since 2016 have emphasized on non-tariff earnings, and Indian Railways unveiled its first non-fare revenue policy in 2017.
  • Indian railways earn a minuscule amount from non-tariff revenue compared to their counterparts in other countries. E.g., Indian railways earn 5% of all its earnings from non-tariff revenue compared with 25-30% in Japan. 

How

  • Selling spaces on railway stations and railway containers for advertising hoardings and billboards.  
  • Leasing out spaces at platforms to ATMs. 
  • Selling branding rights of trains and stations. 
  • Leasing the land around tracks for horticulture purposes

Bibek Debroy Committee  on Railway Restructuring

Bibek Debroy is a noted economist & member of NITI AYOG. The committee was formed under Bibek Debroy to suggest measures to restructure railways. 

Suggestions of Committee

Bibek Debroy Committee  on Railway Restructuring

The committee does not recommend the privatization of Indian Railways. However, it does endorse private entry with the provision of an independent regulator.

1. Reform in Human Resource Management

  • There are 8 services in Railways with different cadres, thus reducing the administrative efficacy. 
  • Recommendations: Unify the Cadre System for optimal utilization of human resources.  

2. Outsourcing

  • Outsource non-core areas, i.e. Police force, schools, hospitals, water bottling, museums etc. 

3. Regulator

  • The Committee has recommended that the Independent RAILWAY Regulator. 
  • Railway Board should continue only as an entity for the management of Indian Railways (PSU).
  • 2018 Update: Rail Development Authority has been constituted with the following functions
    1. Recommend tariff “commensurate with costs.” 
    2. Benchmark service standards
    3. Frame guidelines for track access charges on dedicated freight corridors.

4. Towards entry of private players

  • It recommended separating railway track construction, train operations, and rolling-stock production units under different entities to enable open access to private operators. 

5. Other Recommendations

  • Merge rail budget with General Budget.

Sanjeev Sanyal Committee Report (2021)

The main recommendations of the Committee include

  1. Wind up organizations such as Central Organisation for Railway Electrification (CORE), Centre for Railway Information System (CRIS) etc.
  2. Merge Rail Vikas Nigam into IRCON, Railtel into IRCTC and takeover of Braithwaite and Co. Limited by RITES as their functions overlap.
  3. Outsource the non-core functions. 

Private Train Operators

On selected routes, Private train operators will Design, Build, Finance and Operate (DBFO Model) their own private trains on government tracks  & charge market-linked fares. . Government (Indian Railways) will provide track and signalling infrastructure to them in return for which Private train operator will share a percentage of its revenue with Government.


Timeline of Rail Privatization

2011 
Sam 
Pitroda 
Committee 
Attract private 
investment in building 
railway infrastructure. 
2015 
Bibek 
Debroy 
Committee 
Allow entry of private 
railway operators in goods 
and freight services 
2021 
Bharat 
Gaurav 
Policy 
Allowed Private Operators 
to run trains on theme 
based circuits

Benefits of Rail Privatization

  • It will lead to improved efficiency as private players will bring superior management, technology and amenities.
  • It will lead to a lack of political interference in the railway operations, and decisions will be taken on sound economic principles.
  • Increased competition: The entry of private players will ensure improved quality of service with competitive fares. 
  • Prevent Government’s loss: The revenue generated by the Indian Railways is low and keeps the system always at losses. 
  • Reducing the supply-demand deficit: Since waitlisted passengers comprise ~15% of the reserved passengers. 
  • Private investment: According to estimates, railway infrastructure needs an investment of ₹50 trillion between 2018 and 2030. Given the FRBM restrictions, involvement of private capital is required.  
  • Economic Growth: Private investment in the railways will also lead to economic growth due to its positive spillover effects.

Challenges with Rail Privatization

  • Private monopoly: Privatization in railways might create a private monopoly that might seek to set higher prices and exploit consumers.  
  • Coverage Limited to Lucrative Sectors: With privatization, less popular routes could be eliminated, thus hurting connectivity and rendering some parts of the country virtually inaccessible.  
  • Apprehension among railway employees about job-loss, if Government reduces the number of Government trains.
  • Fragmentation in the railways: Rail privatization broke unified railway operations into infrastructure management and train operating companies in the UK. It led to the absence of clear demarcation of responsibility.

Bharat Gaurav Trains and Bharat Gaurav Policy

  • Bharat Gaurav Trains are private trains that will operate on theme-based circuits (e.g., Ramayana Express connecting places associated with Lord Ram).
  • The operator can lease the train and coaches from the Indian railways and change the interiors provided they comply with the safety norms.
  • The tenure of arrangement can vary from a minimum of two years to the life of the coach. 
  • The operator can also decide the halts, sell advertisement rights etc.

Railway Safety

Main categories of Railway Accidents

  • Derailment of Trains is the primary cause of railway accidents, constituting 50% of railway accidents.
  • Accident on unmanned level crossing gates (36%)
  • Train collisions
  • Rail Fire 
  • Persons standing on railway tracks (e.g., In 2018, 61 people were crushed to death in Amritsar).
  • Natural Causes such as floods, landslides etc. 

Between 2012-2018, a total of 600 rail accidents happened.


Reasons for Railway Accidents

  1. Lack of anti-collision technologies that automatically halts the train if it overshoots a red signal.  
  2. Inappropriate maintenance of tracks: Khanna Committee on Railways Safety commented that nearly 25% of the total railway track in India is overaged.  
  3. Poor Rolling stock: Most trains’ locomotives are not equipped with the Linke Hoffman Busch (LHB) coaches. LHB coaches are more secure than ICF due to the lower centre of mass, preventing it from toppling, turtling, and telescoping.
  4. Rail Fractures: Railway Tracks are made up of strong and durable steel, which can withstand extreme weight and fluctuations in temperature. But Railway fractures do occur due to many reasons like defects during manufacturing, defects during installation and lack of maintenance. These Rail fractures are also among the frequent reasons for derailments.
  5. Government Negligence: Government has formed committees such as Sam Pitroda Committee, Khanna Committee and Bibek Debroy Committee. But all these reports kept on lying dormant and recommendations un-implemented.  

Steps taken by Government

  • Rashtriya Rail Sanraksha Kosh was created with a corpus of 1 lakh crores to promote railway safety.   
  • TCAS (Train Collision Avoidance System): TCAS is based on a combination of railway signalling data, global position, radio frequency identification devices (RFID), software and logic. 
  • Tri-Netra System: Tri-Netra or Three Eyes system is made up of (1) Optical video camera, (2) Infrared video camera and (3) Radar-based terrain mapping system. It will help in avoiding collisions even during the fog.
Tri-Netra System
  • Changing to LHB: Indian Railways is replacing the ICF (Integral Coach Factory) coaches with German-made Linke Hofmann Busch (LHB) coaches. 
  • Setu Bharatam Project: Under the Setu-Bharatam project, unmanned railway crossings are eliminated. 

Way Forward: An independent body like Railway Safety Authority should be constituted to set the standards for Rail Safety and find the reasons and persons responsible for it in case of an accident.


Dedicated Freight Corridors 

Freight operations on the Indian Railways are set to witness a paradigm shift with the completion of its two dedicated freight corridors.


Eastern & Western DFC

Eastern & Western Dedicated  Freight corridor
  Eastern corridor Western corridor
Start Ludhiana in Punjab Dadri in Uttar Pradesh
Funded by World Bank JICA
End Dankuni in West Bengal Jawaharlal Nehru Port Trust near Mumbai
Length 1760 Km 1468 Km

Why DFCs?

  1. It will segregate freight infrastructure passenger transport. It will remedy the issue faced by freight trains, i.e. unpredictable and low speeds of around 25 km per hour. These trains can run at the average speed of 50-60 kph on the Dedicated Freight Corridors, thus leading to faster transport of raw material & finished material from factories to ports and vice versa. 
  2. DFCs will reduce the congestion on existing routes as existing routes are already saturated. 
  3. Allow Passenger Trains to run at faster speed:  Indian railways run fast passenger trains, slow trains, goods trains all on the same track. Hence trains like Rajdhani, which can achieve speeds up to 130kmph, run at an average of 70kmph.  
  4.  Reduce Logistic cost: At present, the logistic cost is about 14% GDP which is 30-40% higher than global benchmarked logistics cost.
  5. DFCs will help India in containing the railway’s falling share of goods traffic, which is 44% in the US and 47% in China compared to just 25% in India.
  6. DFCs will facilitate fresh industrial activity along the corridors.
  7. Carbon emission reduction may help India to claim carbon credits.

Issues / Constraints

  • Issue of Land Acquisition: Due to route alignment, the railways have to acquire large swathes of private land that are already developed, making the construction of the corridor difficult.
  • Double stack vs single stack: The project has adopted different technical standards for WDFC and EDFC. WDFC would have moving dimensions made for double-stacked containers, and moving dimensions for EDFC are being made for single stack container operations. This makes the seamless movement of double-stack trains from WDFC to EDFC impossible.  
  • Not enough bidders: Given the conditions set by the Japanese government (which is giving soft loans) and which stipulates the involvement of a Japanese partner, the total number of bidders has been low for the Western corridor.

High-Speed Rails (HSR)

High-Speed Rail Corridor Plan (Diamond Quadrilateral)

  • Under the High-Speed Railway Corridors (HSR) plan, the Railways intend to run trains at the average speed of 200- 300 Kmph.
  • Ministry of Railways has selected the following six corridors
    1. Delhi-Chandigarh-Amritsar
    2. Pune-Mumbai-Ahmedabad
    3. Hyderabad-Dornakal-Vijaywada-Chennai
    4. Chennai-Bangalore-Coimbatore-Ernakulam
    5. Howrah-Haldia
    6. Delhi-Agra-Lucknow – Patna

Ahmedabad-Mumbai HSR

  • Work on the Ahmedabad-Mumbai line has already been started.
  • It’s details are as follows
Length 509 km
Time to travel 2 km (compared to 7 hours taken by fastest train now)
Top Speed 350 km / hr
Cost of project ₹ 1lakh 8 thousand CRORE
Technology Used Japanese Shinkansen (Bullet Train) Technology
Ahmedabad-Mumbai HSR

Why should India go towards HSR ?

  • Globally, India’s railway network is the fourth largest. Hence, India should build High-Speed Railways to move forward on the learning curve.
  • It has a multiplier effect. 
    1. Improved specialization in construction technologies (as done by China)
    2. The emergence of large MNCs like Alston of France and Hitachi of Japan
  • The development of HSR will have benefits on real estate & facilitate balanced urbanization. For example, the Beijing-Tianjin HSR line helped the growth of Tianjin’s real estate & commercial industry.  
  • Although High-speed railways directly compete with economy class tickets of an airline but have the following benefits vis-a-vis road and airlines
    1. These rail systems have 30% less land requirement in comparison to expressways. 
    2. Energy consumption is 1/3 less than private cars & 5 times less than aeroplanes.
  • HSR system is highly safe. No accident has been reported in the entire history of the Japanese High-Speed Rail.

New Trains

1. Vande Bharat

  • It was formerly known as Train -18.
  • It was made and designed by Integral Coach Factory (ICF) based in Chennai under the Make in India Initiative 
  • These are semi high-speed trains that run at a speed of 160 Kmph (fastest in India).
  • It is an Engineless train running on Electrical Multiple Unit (EMU) Technology.
  • The train has state of the art facilities like onboard WiFi, CCTVs, Rotating Chairs, disabled friendly, intelligent braking system etc. 
  • Budget 2022: 75 new Vande Bharat trains will be added in Indian Railways till 15th August 2023 and 400 new trains in 3 years.

2. Bharat Gaurav Trains

  • Bharat Gaurav Trains are theme-based trains launched in 2021.
  • E.g., Buddhist Circuit Tourist Train (to explore Buddhist places), North East Circuit Train (to explore North Eastern States) etc.

3. Gatiman Express

  • Gatiman Express is a semi-high speed train.
  • It runs on electricity.

4. Antyodaya Express

  • Antyodaya Express is a fully unreserved superfast train that runs on dense routes. 

5. Tejas Express

  • Tejas runs at 130 Kmph and provides advanced amenities such as WiFi services.

6. Uday Express

  • Uday is a double-decker train running on busy routes. 

Introduction to Drainage System

Introduction to Drainage System

This article deals with ‘Introduction to Drainage System ’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Terminology

Channel A defined zone which has a certain depth in which there is continuous flow of water under normal conditions.
Drainage The flow of water in well defined channel is known as Drainage .  
Drainage System The network of channels which drains a region is known as Drainage System.  
Drainage Basin The drainage basin is the area drained by the river and it’s tributaries.  
Catchment / Catchment Area The river drains the water collected from a specific area. This area is known as the Catchment Area or Catchment .  
Water Divide / Watershed Watershed divides the one catchment area from other catchment area. It is also known as Water divide.  
River Regime The seasonal flow of water in a river is known as River regime. Hence, if the water availability is uniform around the year, it is known as Uniform River Regime. Whereas rivers where the water is seasonal, it is known as Non-uniform River Regime. Such seasonal rivers are also known as Ephemeral rivers.  
Inland Drainage Rivers which don’t reach the ocean . In desert or arid regions, such rivers lead to the formation of Salt Lakes or Playa Lakes .

Types of drainage pattern

Geometric system of streams in a region is determined by.

1. Slope 3. Hydraulic Variability.
2. Difference in rock resistance to erosion 4. Structural  control of Landscape.

1 . Antecedent or Inconsequent

  • Antecedent drainage pattern is one in which a  part of a river slope and the surrounding area gets uplifted but the river sticks to its original slope, cutting through the uplifted portion forming deep gorges
  • Eg : Those rivers which existed before upheaval of Himalayas like Indus, Satluj, Ganga, Brahmaputra, Arun, Tista etc. . These rivers originates in Tibet and cut across Himalayas forming deep gorges.

2. Consequent

  • Rivers which flow in direction of slope.
  • Most peninsular rivers like Godavari, Krishna, Cauvery etc.

3. Superimposed /Superinduced

  • In this, drainage pattern exhibits discordance with underlying rock because it originally developed on a cover of  rocks that has now disappeared .
  • The river has enough erosive power that it can cut through any kind of bedrock, maintaining its former drainage pattern.
  • Damodar, Subarnarekha, Chambal, Banas etc.

4. Dendritic

  • Drainage in which branches give appearance of tree .
  • Dendritic pattern develops in a terrain which has uniform lithology, and where faulting and jointing are insignificant.
  • Most rivers of Indo-Gangetic plain show Dendritic drainage pattern.
Introduction to Drainage System

5. Trellis

  • Rectangular pattern where two sets of structural control occur at right angle.
  • Eg : Drainage pattern of Singhbhum(Chotanagpur).
Trellis Drainage Pattern

6. Obsequent

  • In Obsequent drainage pattern, tributaries intend to flow upstream instead of downstream.
  • Eg : Arun river which is tributary of Kosi & Suru of Indus.

7. Rectangular

  • The main stream bends at right angles and the tributaries join at right angles creating rectangular patterns.
  • It differs from trellis as it is more irregular.
  • It is found in Vindhyan mountains.
Rectangular Drainage Pattern

8. Radial

  • Outflowing rivers , away from central point.
  • Radial pattern tends to develop on flanks of a dome or volcanic cone.
  • Rivers originating from Amarkantak hills , Chotanagpur Plateau & Mikir hills .
Radial Drainage Pattern

9. Annular

  • Subsequent stream flows curving prior to joining the consequent stream.
  • It is not very common . In India, it is found in Nilgiri hills of Tamil Nadu & Kerala.

10 . Parallel

  • Rivers flow parallel to each other. In this, rivers will not meet but keep on running parallel.
  • Small rivers originating in western ghats & discharging water in Arabian sea.

11. Deranged

  • Uncoordinated pattern of drainage, characteristic of a region recently vacated by ice sheet & has  not adjusted according to solid rocks underlying.
  • Eg : Drainage pattern found in glaciated valleys of Karakoram.
Deranged Drainage Pattern

Indian rivers

There are various ways to classify Indian Rivers.

1 . On basis of Discharge of Water

  • All Indian rivers discharge water either in Arabian Sea or Bay of Bengal.
  • Nearly 77%  of the drainage area consisting of the Ganga, the Brahmaputra, the Mahanadi, the Krishna, etc. is oriented towards the Bay of Bengal while 23% comprising the Indus, the Narmada, the Tapi, the Mahi and the Periyar systems discharge their waters in the Arabian Sea.
  • They are separated from each other through the Delhi ridge, the Aravallis and the Sahyadri.
  • It should be mentioned here that the over 90% of the water carried by the Indian rivers is drained into the Bay of Bengal; the rest is drained into the Arabian Sea or forms inland drainage.

2. On Basis of Size of Watershed

Major River Basins Catchment area of more than 20,000 sq. km 14
Medium River Basins 2,000 to 20,000 sq. km 44
Minor River Basins Less than 2,000 sq. km 55

Ranking (catchment area)

Ganga Mahanadi
Indus Narmada
Godavari Kaveri
Krishna Tapi
Brahmaputra Pennar

3. On Basis of Mode of Origin

  1. Northern/Himalayan Rivers
  2. Peninsular Rivers.
    • Although it has the problem of including  Chambal,  Betwa, Son, etc. which are much older in age and origin. than other rivers that have their origin in the Himalayas, it is the most accepted basis of classification.
Rivers 
Himalayan 
Rivers 
Indus 
Ganga 
Brahmaputra 
Peninsular 
Rivers 
Mahanadi 
Godavari 
Krishna 
Cauvery 
Narmada 
Tapti

This marks the end of our article on Introduction to Drainage System. For other articles on geography, CLICK HERE.

Plateaus

Plateaus

This article deals with ‘Plateaus.’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Introduction

  • Plateau is an elevated tract of relatively flat land , limited on atleast one side by steep slope falling abruptly
  • Eg: Tibetan plateau.

Reasons for formation of Plateaus

There are many reasons for the formation of Plateaus

  • When two mountain ranges are forming, then landmass in between them rise too &  Plateaus are formed .
  • Deposition from lava – if lava is basaltic it will spread easily &  form flat elevated surface
  • Deposition from wind over long time => After compression & solidification of deposited material plateau will form.
  • When upland of any surface is eroded due to glaciers, plateau is formed.

Types of Plateaus

1 . Intermontane plateau

  • Intermontane plateaus are  highest, largest & most complex plateaus of world.
  • Intermontane plateaus are enclosed and surrounded by mountain ranges from different sides.

Examples include

a. Tibetan Plateau

  • Stretches 1000 km north to south &  2500 km east to west & average elevation is 4500m  => called Roof of the world .
  • Bounded by Kunlun Mountains in the north & Himalayas in the south. 
  • Many major rivers of Asia like Indus, Brahmaputra etc rise here & also holds constellation of salt & freshwater lakes .

b. Plateau of Bolivia

  • Lies largely  in Bolivia
  • It has average elevation of 1350 m.
  • Highland  was uplifted during tertiary period when the Andes were formed
  • Contrary to Tibetan Plateau, it is very dry and  has no exterior drainage

c. Plateau of Mexico

  • Plateau stands between the eastern and western Sierra Madre Mountains.
  • It has average elevation between 1800 meters to 2300 meters
  • Large  parts of this Plateau are very dry.

d. Colorado Plateau

  • Situated in USA between Cascade Range and Rocky Mountains
  • It is situated at elevation

e. Anatolia Plateau

  • Lies in Turkey between Taurus & Pontic Range
  • It’s elevation is cause of cool weather of Turkey 
Intermontane Plateaus

2. Piedmont or Border Plateau

  • These  Plateaus border mountain ranges and owe their present position to the same uplifts that raised the mountains. 
  • Examples include
    1. Piedmont Plateau on the border of Appalachian Mountains
    2. Patagonia Plateau in South America

3. Volcanic Plateau

  • Volcanoes form variety of plateaus. 
    • Larger : built by BASALTIC lava flow.
    • Small : formed by resistant lava caps that aren’t eroded & maintain its elevation after surrounding land has been worn away.
  • Examples are
    • Columbia Snake Plateau .
    • Deccan Plateau , India.
    • Shan Plateau , Myanmar
    • Katanga Plateau, Congo
    • North Island in New Zealand
Volcanic Plateaus of the world
Volcanic Plateaus of the world

4. Erosional Plateau

  • Form in semiarid regions where streams have cut away portions of high lands.
  • Examples include
    1. Allegany Plateau near  New York 
    2. Cumberland Plateau near Appalachians in USA

5. Depositional Plateau

  • Formed due to depositional action of wind
  • Examples include Loess Plateau in China => It is formed due to process of deposition of sediments carried from the desert  by the Anticyclonic  winds which develop over Russia and come to China shedding their load in this area
Loess Plateau

6. Dome Plateau

  • These plateaus are uplifted by folding and faulting processes  into a broad dome.
  • Entrenched Meanders are feature of these plateaus
  • Examples include Ozark Plateau of USA

7. Glacial Plateau

  • These are formed due to  erosional action of glaciers.
  • Examples include
    1. Laurentian Plateau of Canada (North America)
    2. Garhwal Plateau of India

Importance of Plateaus

  • Plateaus have large amount of   mineral wealth like Gold, Iron, Copper, Diamond, Manganese, Mica , Granite etc. which forms industrial base of any economy. Eg : Katanga Plateau of Congo is very rich in copper and Deccan Plateau of India is very rich in resources.
  • Plateaus are have more plain regions as compared to pure mountainous regions which helps in development of means of transport. Rail and road transport is lesser costly in plateau regions as compared to mountainous regions.
  • Plateau regions have abrupt slopes which are beneficial for setting up hydroelectrical centres thus helping in overall development of the region
  • Plateaus greatly effect the climate of region . For example Tibet plateau divides western Jet Stream in two parts while in summer and helps to create low pressure over Indian subcontinent which results into attraction for Monsoons 
  • They are important agriculturally as well . Eg : Deccan Plateau in India has black soil which is unmatchable for production of Cotton and Sugarcane.
  • Plateaus especially Intermontane Plateaus are great source of water resources as well. Eg: Large number of rivers like Indus , Brahmaputra etc originates from Tibet plateau.

Continental Drift and Plate Tectonic Theory

Continental Drift and Plate Tectonic Theory

This article deals with ‘Continental Drift and Plate Tectonic Theory.’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Continental Drift Theory

  • Given by Alfred Wegener (German Meteorologist)  in  1912   . It speaks about rifting and drifting of continents .
  • According to Wegener, about 250 million years ago all the continents formed a single continental mass and mega ocean surrounded the same. 
    • Super continent was named PANGAEA, which meant all earth.
    • Mega-ocean was called PANTHALASSA, meaning all water.
  • He argued that, around 200 million years ago, the super continent, Pangaea, began to split
    • Pangaea broke to Laurasia/ Angaraland (forming Northern Continents) and Gondwanaland (Southern Continents) with Tethys Sea between them. 
    • Subsequently, Laurasia and Gondwanaland continued to break into various smaller continents that exist today. (Note – India was part of Gondwanaland.)
  • Interesting theory but was scrapped saying it GEO-POETRY because he wasn’t able to explain forces of movement.

Continental Drift theory was based on following clues

a. Continental fit / Jig Saw Fit

  • Continental lands can be joined together like jig saw puzzle.

b. Rocks of same age across oceans

  • Belt of ancient rocks of 2,000 million years from Brazil coast matches with  western Africa. 
  • Geological Structure of Appalachian Mountains matches with Morocco and Algeria in North Africa.

c. Fossils

Mesosaurus Freshwater reptile found in Africa & South America.
Glassopteris Fern found on all southern continents.
Lemur Found in India, Africa and Madagascar.

d. Placer Deposits

  • The occurrence of rich placer deposits of gold in the Ghana coast and the absolute absence of source rock in the region => gold bearing veins are in Brazil => Ghana & Brazil Plateau used to lay side by side.

e. Tillite

  • Tillite are the sedimentary rock formed out of deposits of glaciers.
  • Gondwana system of sediments from India has counter parts in six different landmasses of Southern Hemisphere.
Pr

Forces for Drifting

  • Wegener suggested that movement responsible for drifting of continents was caused by pole-fleeing force and tidal force.
  • Polar-fleeing force relates to the rotation of the earth.
  • Tidal force—is due to the attraction of the moon and the sun that develops tides in oceanic waters.
  • Wegener believed that these forces would become effective when applied over many million years. However, most of scholars considered these forces to be inadequate 

Post Drift Studies

  • It is interesting to note that for continental drift, most of the evidences were collected from the continental areas .
  • Number of discoveries during the post-war period added new information to geological literature. Particularly, the information collected from the ocean floor mapping provided new dimensions for the study of distribution of oceans and continents.

Convectional Current Theory

  • Wegener wasn’t able to explain the  force  behind Continental Drift.
  • Arthur Holmes in 1930s discussed the possibility of convection currents operating in the mantle portion. These currents are generated due to radioactive elements causing thermal differences in the mantle portion. Holmes argued that there exists a system of such currents in the entire mantle portion.
  • These convection currents are nothing but molten rocks
    • Rising limb :  it will pressurise crust in such a way that crust will break .
    • Diverging limbs :  take crust away from each other .
    • Descending limbs : make two crusts to collide (like Indian & Eurasian plate ).
  • According to Holmes , these Convection Currents are the Driving Force . This was an attempt to provide an explanation to the issue of force, on the basis of which contemporary scientists discarded the continental drift theory.
Convectional Current Theory

Ocean  Seafloor Spreading Theory

Post war studies using which Ocean Map was prepared showed that ocean floor is not just a vast plain but it is full of relief.

Mapping of the ocean floor and palaeo-magnetic studies of rocks from oceanic regions revealed the following facts :

  • It was realised that all along the mid-oceanic ridges, volcanic eruptions are common and they bring huge amounts of lava
  • Ocean crust rocks are much younger than the continental rocks. The age of rocks in the oceanic crust is nowhere more than 200 million years old. Some of the continental rock formations are as old as 3,200 million years.
  • Age  of the rocks increases as one moves away from  crest.
  • Sediments  on the ocean floor are unexpectedly very thin => nowhere was  sediment column found be older than 200 million years.
  • Deep trenches have deep earthquake occurrences while in mid-oceanic ridge areas, earthquake foci have shallow depths
  • Concept of zebra strip / Magnetostratigraphy : rocks equidistant on either sides of mid-oceanic ridges show  similar magnetic properties

This led Hess (1961) to propose his hypothesis, known as the “sea floor spreading”

  • Constant eruptions at  crest of oceanic ridges cause  rupture of the oceanic crust and  new lava wedges into it, pushing the oceanic crust on either side. The ocean floor, thus spreads.
  • Ocean floor that gets pushed due to volcanic eruptions at crest, sinks down at the oceanic trenches & gets consumed (Seafloor Spreading Theory).
Ocean  Seafloor Spreading Theory

Plate Tectonic Theory

  • Given in 1967 by McKenzie & Parker
  • Tectonic plate ( lithospheric plate) is a massive slab of solid rock, generally composed of both continental and oceanic lithosphere. Plates move horizontally over the asthenosphere . Its thickness range varying between 5-100 km in oceanic parts and about 200 km in the continental areas.
  • A plate may be referred to as the continental plate or oceanic plate depending on which of the two occupy a larger portion 
    • Pacific plate is largely an oceanic plate
    • Eurasian plate may be called a continental plate.
  • Theory of plate tectonics proposes that the earth’s lithosphere is divided into seven major and some minor plates.
  • Young Fold Mountain ridges, trenches etc are formed due to movement and interaction of these plates

The major plates are

  • Antarctic and the surrounding oceanic plate
  • North American
  • South American
  • Pacific plate.
  • India-Australia-New Zealand plate .
  • Africa with the eastern Atlantic floor plate .
  • Eurasia and the adjacent oceanic plate.

Some important minor plates are

  • Cocos plate : Between Central America and Pacific plate .
  • Nazca plate :Between South America and Pacific plate .
  • Arabian plate : Mostly the Saudi Arabian landmass.
  • Philippine plate : Between the Asiatic and Pacific Plate .
  • Caroline plate : Between the Philippine and Indian plate (North of New Guinea) .
  • Fuji plate : North-east of Australia.
  • 2017 update – Zealandia is now considered separate Continent/Plate

These plates have been constantly moving over the globe throughout the history of the earth.

  • All the plates, without exception, have moved in the geological past, and shall continue to move in the future as well.
  • Pangaea of Wegner was also result of convergence of continental masses
Movement of Continents in history

Plate Boundaries

There are three types of plate boundaries according to Plate Tectonic Theory (these three types of plate boundaries are discussed in detail below)

Type of Boundaries

Rate of Plate Movement

  • Strips of normal and reverse magnetic field that parallel the mid-oceanic ridges help the scientists to determine the rates of plate movement.
  • These rates vary considerably.
    • Arctic Ridge: slowest rate (less than 2.5 cm/yr),
    • East Pacific Rise in the South Pacific : fastest rate (more than 15 cm/yr).

Force for the Plate Movement

  • Convectional Currents which were first explained by Hess in his Convectional Current Theory was the main force behind plate movement

Side Topic : Palaeomagnetism & how it prove Plate Tectonics

Palaeomagnetism is the study of the record of the Earth’s magnetic field in rocks and sediments

How it proves Plate Tectonic Theory

  • Magnetostratigraphy, with rocks equidistant on either sides of mid-oceanic ridges show  similar magnetic properties
  • Polar wandering – Magnetic minerals formed at same time but on different continents points have different orientation .  So, there were either multiple north poles during the same time period or that the continents moved in relation to a single north pole. Geophysicists concluded that the magnetic poles remained stationary, and the continents moved
  • Palaeomagnetism is also used to match once joined landmasses that are now separated. For example, the orientation of magnetic minerals along the eastern coast of South America very closely matches that of similar minerals on the western coast of Africa. 

Convergent Plate Boundaries

Convergent plate boundary is the margin where two plates collide with one another.

Convergent plate boundary

Convergent Plate Boundaries can be of three types :-

1 . Ocean Ocean Convergent Boundary

  • Denser of the two oceanic plates is subducted   . It goes to Asthenosphere & generate new Magma .
  • Andesitic Magma will from in this case . Andesitic Magma is less  mobile and solidifies quickly. As a result,  underwater Volcano or Volcanic island arc will form in this case.
  • Characterised by  Trenches , Underwater Volcanoes , Volcanic Island Arc and Earthquakes .
  • Island arc  (and not single island) will be formed because they will be formed on whole boundary where Ocean-Ocean plate is converging. All these islands will be volcanic islands .
Ocean Ocean Convergent Boundary

2. Ocean – Continental Convergence Boundary

  • Oceanic Plate is denser than Continental Plate . Hence, Ocean plate will be subducted into Asthenosphere &  melt down there. But at the same time, due to the great compressional force between two converging plates, folding will happen on the Continental Plate , resulting in formation of Marginal Fold Mountains . As we know, folding happens along the zones of  weakness , hence, when Magma of the subducted  Ocean plate will rise , it will  come out of the crust through these weak zones  resulting in formation of Volcanic Peaks .  
  • Hence, Volcanic mountains ranges, Trench and earthquakes  are common on boundaries
  • Examples of such volcanic mountain ranges are
Andes  mountains South America
Rockies North America
Atlas Africa
Ocean - Continental Convergence Boundary

3. Continental – Continental Convergent Boundary

  • When continental plate converges into continental plate , crust at  both sides is tool light  & buoyant to be subducted. Both are  compressed against each other and folding happens. Hence, in this case Fold mountain Belt forms.
  • No Volcanism but powerful earthquakes are created in this region .
  • Himalayas & Urals  are formed in this way due to convergence of Indo-Australian and Eurasian plates.
  • Pressure between plates is so high that metamorphic rocks form there.

Divergent plate Boundaries

  • Divergent plate boundary is the margin where two plates move apart. For instance, African plate and South American plate
  • Divergent plate boundary is termed as the constructive plate boundary as it leads to the formation of new lithosphere .
Divergent plate boundary

Divergent plate boundaries are of two types :-

1 . Ocean – Ocean Divergent Boundary

  • Creation of new crust takes place at submarine mountain ridge . Ocean crust is rifted apart & basaltic magma wells up to fill the opening.
  • Basaltic Magma will come out from the Mantle. Since basaltic magma  is very mobile, hence it will spread out. This magma hardens & forms igneous rock . Since magma is basaltic, hence ocean crust is basaltic in nature .
  • Mid-Atlantic Ridge is an ideal example of a submarine mountain ridge in the Atlantic Ocean. It is the longest mountain ridge in the world. It extends for about 16,000 km, in a ‘S’ shaped path, between Iceland in the north and Bouvet Island in the south
  • Water from hydrothermal vents (along the submarine ridges) is rich in dissolved minerals and supports organisms like chemo-autotrophic bacteria.

2 . Continental – Continental Divergent Plate

  • Rift  valley along with block mountains are formed when two continental  plates move apart.
  • Initially it leads to the development of a small body of water . But if rifting continues , body of water becomes bigger to juvenile ocean and consequently to Large Ocean.
  • Example : The Great Rift of Africa

Side Topic : Great Rift of Africa

  • In Great African Rift Valley, Continental Continental Divergence is observed leading to formation of Rift Valley.
  • Almost all the lakes in Africa are in the Rift Valley generated by diverging of  continental Plates except Lake Victoria.
Great Rift of Africa

Transform Plate Boundary

  • Where two plates are sliding past each other.
  • They are  under shear stress.
  • The lithosphere is neither destroyed nor created by the transform plate boundary. Hence , it is called Conservative or passive plate boundary.
  • Earthquakes are common & Volcanoes are not formed at Transform boundaries. Whenever plate boundary is active, Earthquakes are also experienced in that region.

  • Example –San Andreas Fault in USA (Pacific Plate & North American) , Chile etc
San Andreas FAult

Ocean Salinity

Ocean Salinity

This article deals with ‘Oceanography: Ocean Salinity’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Introduction

  • Salinity of Solution is defined as amount of salt in 1000 gram of water .
  • Salinity of ocean water is 35.5 ppt ( parts per thousand)  & maximum amount is of common salt.
Sodium chloride 78%
Magnesium Chloride 12%
Magnesium sulphate 3.5%
Calcium Sulphate 2.5%

Why Sodium Chloride (NaCl) is present in highest proportion ?

  • Every salt has cycle & they remain in sea water for specific time( called residual time) & then precipitated to bottom surface .
  • Sodium (Na) & Chlorine (Cl) has highest residual time in ocean water leading to very gradual removal => that is why they are present in highest proportion .

Salt Budget

  • Irrespective of absolute salinity,  proportion of above salts remain same in all parts of the world  .
  • Amount of addition or extraction of fresh water compared to salt content in ocean water decides absolute salinity of oceans .
  • Salt Budget  = Budget of addition of salt & removal of salt .

Sources of salts on ocean water.

  • Sediments carried by rivers (most important) .
  • Submarine volcanism at Mid Oceanic Ridge .
  • Chemical reaction between rocks of geothermal vent of volcano & cold water.
  • Erosion of oceanic rocks and wave erosion of coastal rocks  .

Removal of Salts in ocean water.

  • Physical Removal :  waves break at beaches ie salt spray .
  • Biological removal : marine life forms extract calcium from sea water for their bones & shells .

Factors effecting salinity

Evaporation Higher the rate of evaporation ,higher is salinity.
Temperature Warmer parts are more saline than frigid ones.
Precipitation Higher the precipitation, lower is the salinity.
Influx of Freshwater Influx of freshwater leads to lower salinity .
Atmospheric pressure  
Circulation of Ocean water Stagnant water has more salinity (Eg: Sargasso sea).
Windy situation Wind accelerate evaporation => windy situation = more saline

Salinity of Oceans

  • Standard  salinity of ocean water is 35.5 ppt ie salinity of Atlantic ocean .
Greater than 35.5 High saline.
Lower than 35.5 Less  saline.
  • Some highly saline lakes . Man  seldom drown in sea with high salinity because water is  highly dense .
Dead Sea 238 ppt West Asia
Lake Van 330 ppt Turkey
Great Salt Lake 220 ppt USA
Lake Urmia   Iran

Overall pattern of Salinity across world

Ocean Salinity

a. Latitudinal variation

  • Salinity is highest at tropics(not Equator)  & decreases on both sides.
  • This is due to Interplay of evaporation & precipitation & other complex interactions.

b. Hemispheric variation

  • Northern Hemisphere is warmer => high evaporation => more saline .
  • But southern Pacific => Roaring 40, furious 50 , Shreaking 60 , Screaming 70 => very fast winds . Hence in Pacific ocean , southern hemisphere has more salinity

c. Local Variation in Salinity

Warm ocean currents – Increases temperature of water => equivalent to High evaporation .
– Leads to more salinity.
Upwelling Cooler water from depth come to surface => low salinity.
Transport by currents The North Sea, in spite of its location in higher latitudes, records higher salinity due to more saline water brought by the North Atlantic Drift.

d. Enclosed Seas

Tropical region – Warmer than open sea .
– Will lead to high salinity.
– Eg Mediterranean Sea , Persian Gulf etc. 
High Latitude – Cooler than open sea .
– Lower salinity than open seas .
– Eg Baltic Sea, Gulf of Bothnia etc .

e. Inflow of large rivers

  • Ganga – Brahmaputra => flow into Bay of Bengal => large freshwater .
  • Bay of Bengal is less saline than Arabian Sea.

f. Glaciers

  • Those oceans /seas which receive greater glacier water are less saline
  • Baltic Sea is very less saline because of this reason .

Ocean Temperature

Ocean Temperature

This article deals with ‘Oceanography: Ocean Temperature’ This is part of our series on ‘Geography’ which is important pillar of GS-1 syllabus . For more articles , you can click here

Introduction

  • Temperature of ocean water is important because
    1. Life of Phytoplankton & Zooplankton depend on it .
    2. Affects climate of coastal lands .
  • Points to note :-
    1. Main source of Energy on Earth is sun ie insolation .
    2. Oceans play important role in energy & temperature regulation of earth. Because of its specific heat, water doesn’t  get heated &  does-not get cold very fast . Hence, water  can store energy for very long time .
    3. Average temperature of ocean from surface to bottom is 3-5  Celsius.
    4. But average surface temperature of ocean is 25 Celsius.

Range of temperature

Daily/ Diurnal range of temperature

  • Difference between maximum & minimum temperature of a day.
  • Daily range of temperature is almost insignificant in case of rivers & is less than 1 degree C at max
  • Tropical water has higher diurnal range than equatorial waters because cooling & heating of water is rapid under clear sky .

Annual range of temperature

Average is 12 degree C but lot of regional variation.

  • Higher in case of enclosed oceans than open seas
  • Bigger the size lower annual range of temp because of more mixing .

Distribution pattern of Temperature

Studied in two ways

1 . Horizontal  distribution of temperature in oceans

Factors impacting horizontal distribution of temperature in oceans

a. Latitudinal Variation

  • There is decrease in temperature while going from equator toward poles because of decrease in insolation
  • But highest temperature is found not at equator but at tropics
    • Reason : High rainfall & cloud cover at the Equator resulting in High Albedo / reflection of sun-rays by clouds

b. Prevailing Winds

Direction of the wind affects the distribution of temperature of ocean water.

  • Off shore winds blowing from the land towards ocean or sea raise the temperature of ocean water.
  • Winds blowing from snow covered regions in winter lower the surface temperature

c. Hemispheric Variation

  • Waters in Northern Hemisphere warmer than Southern Hemisphere . Reason is the oceans in the northern hemisphere receive more heat due to their contact with larger extent of land than the oceans in the southern hemisphere.
  • Isotherms in north aren’t regular while in Southern Hemisphere regular.

d. Enclosed Sea

  • Marginal seas of tropics ( like Mediterranean Sea)  are warmer than open Ocean and marginal seas of  temperate region (eg Gulf of Bothnia)  are cooler than open sea.
  • Reasons
    • less mixing of water.
    • Land heats up surrounding waters too.

e. Ocean Currents

  • Warm currents have warming effect on ocean water
  • Cold currents have cooling effect on ocean water

f. Upwelling & Downwelling

  • Upwelling – Brings cool water from depth.
  • Downwelling – opposite ie warmer .

g. Salinity

  • If the sea water is more saline, its temperature will be higher because highly saline water contains more energy on the other hand the temperature of less saline water is low.

Horizontal distribution of Ocean Temperature

  • The average temperature of surface water of the oceans at equator is about 27°C and it gradually decreases from the equator towards the poles.
  • The rate of decrease of temperature with increasing latitude is generally 0.5°C per latitude
  • The average temperature is around 22°C at 20° latitudes, 14° C at 40° latitudes and 0° C near poles.
  • The oceans in the northern hemisphere record relatively higher temperature than in the southern hemisphere. The average annual temperatures for the northern and southern hemisphere are around 19° C and 16° C respectively. This variation is due to the unequal distribution of land and water in the northern and southern hemispheres.
  • The highest temperature is not recorded at the equator but slightly towards north of it.
800N— 
400N 
00 
800S 
32 
30 
28 
26 
24 
22 
20 
18 
16 
14 
12 
10 
500F 
V. 
1500F 
LONGITUDE 
Figure 5.12 Sea surface temperature in July 1997

2. Vertical Distribution of Temperature of Ocean Waters

  • Maximum temperature is on the surface  because it receives insolation.
  • Transmitted to lower sections of ocean by convection.
  • Solar rays can penetrate very effectively till 200m  but seldom go below 1000 m . As a result, temperature falls very rapidly from 200m  till 1000m & after that , rate of decrease of temperature is very slow (rate & not absolute temperature).

Can be divided into three zones

First layer

  • Top layer of warm oceanic water & is 200 m thick.
  • Temperature ranges from  20 to 25degree  & no large variation with depth ( almost constant )
  • Present in tropics throughout year , in mid latitudes in summer & in cold areas never present .

Second layer

  • Thermocline layer
  • Below first layer from 200m to 1000 m.
  • Rapid rate of decrease of temperature to 4 C  with increase in depth from 200 m to 1000 m .
  • Rate of decrease is rapid at equator & tropics than towards pole because temperature already is very low in Polar Region
  • In polar , waters  are already at around 4C . Hence, this layer is not present in polars .

Third layer

  • Very cold & extend upto deep ocean floor.
  • Decrease in temperature with depth is almost nill.
  • Polar areas have only this layer from above till ocean floor.
Vertical pattern of temperature of Oceans