Exploration of Polymetallic Nodules and Polar Vortex (Download PDF)

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India՚s rights to explore Polymetallic nodules from seabed in Central Indian Ocean Basin (CIOB) . Extended by five years by International Seabed Authority, till 2022. India became the first country to have received the status of a pioneer investor in 1987.

  • Presently having an area of 75,000 square km, located about 1600 km away from her southern tip.

GSI (Geological Survey of India)

  • Presence of micro manganese nodules around Lakshadweep Sea.
  • Confirmed presence of Phosphate sediment off Karwar, Mangalore and Chennai coast.
  • Gas Hydrates in Mannar Basin and Cobalt bearing Ferro manganese crust from Andaman Sea.

Polymetallic Nodules and the Polymetallic Nodules Programme (PNP)

  • Also called manganese nodules.
  • Rock concretions formed of concentric layers of iron and manganese hydroxides around a core.
  • They contain nickel, copper, cobalt, lead, molybdenum, cadmium, vanadium, titanium and rare earth metals besides manganese and iron.
  • PNP orientation is towards exploration and development of technologies for eventual extraction of nodules from the Central Indian Ocean Basin (CIOB) allocated to India.

Consists of

  • Survey and Exploration.
  • Environmental Impact Assessment (EIA) Study.
  • Technology Development (Mining) .
  • Technology Development (Extractive Metallurgy) .

Polar Vortex

  • Is a large area of low pressure and cold air?
  • Surrounding both of the Earth՚s poles.
  • A whirling mass of cold air circulating in the mid- to upper-levels of the atmosphere.
  • Flow is counter-clockwise.
  • Flow of air helps in containing the colder air within the poles.

Polar Vortex ″ event

  • It helps keep a current of air (the jet stream) travelling around the globe in almost a circular path.
  • Current contains the cold air north of it and the warm air south of it.
  • The polar vortex sometimes becomes less stable and expands during the winters.
  • Lack of a strong low-pressure system.
  • Results in resulting in jet stream losing the hold to keep it in line, and becoming wavy.
  • During a polar vortex event wave of cold air will be pushed down south.
  • Not confined to the US.
  • Cold surges are experienced by portions of Europe and Asia.

Earthquake Swarm in Palghar, Maharashtra

  • The Palghar district is in northern Maharashtra.
  • An unusual frequency of earthquakes since November, 2018.
  • 30 low-intensity earthquakes since November 2018- Dahanu town in Maharashtra՚s Palghar district.
  • Magnitudes of the quakes ranged between 3 and 4.1 on the Richter scale.
  • Data collected points towards an “earthquake swarm” .

Earthquake Swarm

  • A series of many (sometimes thousands) low magnitude earthquakes.
  • There is no presence of a discernible main shock.
  • Occur in a localized region and over a period of time ranging from days, weeks to even months.
  • There is no clear sequence of foreshocks, main quakes and aftershocks.
  • Sometimes accompanied by acoustic or sound emissions.

Deccan Region and the Need for Caution

  • Sequences of low-intensity quakes are common in areas that have been hit previously. E. g. Saurashtra in Gujarat, Koyna in Maharashtra.
  • Also seen in areas without a history of seismic activity and, swarms are normal in peninsular India.
  • No mining activity has been found.
  • To explain the cause of earthquakes no mining activity has been found.
  • Along the Deccan plateau seismic waves travel faster in hard rocks which help the tremors dissipate faster.
  • Loose soil which makes the waves stay longer, release more energy and cause more damage.
  • Not limited to the Peninsula.
  • The Himalayan swarm was later attributed to low strength of the earth՚s crust.
  • Identifying the quakes as a swarm would suggest there is little threat of a deadlier one hitting in the near future.
  • The possibility of either the quakes now subsiding or of a big one coming cannot be ruled out yet.
  • There is a need to draw up a community disaster management plan with Standard Operating Procedures by the district authorities.

Magnetic North Pole Shifting

  • Drifting fast away from the Canadian Arctic and towards Russia.
  • Geographic poles are being defined by the axis around which the planet rotates and are fixed.
  • The Earth behaves much like a giant bar magnet.
  • Behaviour defines its magnetic north and south poles.

Causes of the Magnetic Field

  • Earth՚s magnetism lies in its outer core which is a more than 2,000-km layer surrounding the central core or the innermost part.
  • The magnetic poles do not coincide with the geographical poles due to the constant motion.
  • The magnetic behaviour of the Earth is far more complex than that of a simple bar magnet.
  • Outer core is comprised of liquid iron and some other metals like nickel.
  • Due to Earth՚s rotation, the liquid iron is in constant motion and it is this motion which produces a magnetic field.

Recent Development

  • The magnetic north pole has been moving hundreds of miles across the Canadian Arctic towards Russia since 1831.
  • The pace of this movement has suddenly increased.
  • The World Magnetic Model (WMM) tracks the movement.
  • The faster movement of the magnetic north pole was responsible for WMM inaccurate such that it was about to exceed the acceptable limit for navigational errors.

Significance

  • The phenomena happening inside the earth can only be studied indirectly or through computer modelling.
  • There is no certainty about the fast movement.
  • The shifting of magnetic north pole would reveal insights into the phenomena happening deep inside the Earth՚s surface.

Consequence

  • A standalone school compass will result in the reorientation of itself to the new resultant magnetic north pole.
  • The compasses used in modern instrumentation are much more sophisticated, digital and more accurate.
  • Dependence of the transportation sector especially aviation and shipping on the position of magnetic north.
  • The compass needs to be recalibrated to reflect the change in the magnetic north pole.
  • A set of software has been released by the WMM for updating the instruments to the new positions of the magnetic north pole.

- Published/Last Modified on: March 28, 2020

Geography

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