💥Join UPSC 2027,2028 Mentorship (July Batch) + XFactor Notes & Microthemes PDF
Talk to Mentor

Civilsdaily

Login

GS Paper: GS1

  • ‘Ring of Fire’ Solar Eclipse

    A rare celestial event, an annular solar eclipse popularly called as the ‘ring of fire’ eclipse, will be visible on June 21, 2020 from some parts of Northern India. The first solar eclipse of this year takes place on the summer solstice, which is the longest day in the Northern Hemisphere.

    Try this question from CSP 2019:

    Q. On 21st June, the Sun

    (a) Does not set below the horizon at the Arctic Circle

    (b) Does not set below the horizon at Antarctic Circle

    (c) Shines vertically overhead at noon on the Equator

    (d) Shines vertically overhead at the Tropic of Capricorn

    What is the Solar Eclipse?

    • A Solar Eclipse happens when the moon while orbiting the Earth comes in between the sun and the Earth, due to which the moon blocks the sun’s light from reaching the Earth, causing an eclipse of the sun or a solar eclipse.
    • According to NASA, people who are able to view the total solar eclipse are in the centre of the moon’s shadow as and when it hits the Earth.
    • There are three types of eclipses: one is a total solar eclipse, which is visible only from a small area on Earth. A total solar eclipse happens when the sun, moon and Earth are in a direct line.
    • The second type of a solar eclipse is a partial solar, in which the shadow of the moon appears on a small part of the sun.

    Annular Solar Eclipse

    • The third kind is an annular solar eclipse, which happens when the moon is farthest from the Earth, which is why it seems smaller.
    • In this type of an eclipse, the moon does not block the sun completely, but looks like a “dark disk on top of a larger sun-coloured disk” forming a “ring of fire”.
    • Furthermore, during a solar eclipse, the moon casts two shadows on the Earth; the first one is called the umbra, which gets smaller as it reaches the Earth.
    • The second one is called the penumbra, which gets larger as it reaches the Earth.
    • According to NASA, people standing in the umbra see a total eclipse and those standing in the penumbra see a partial eclipse.

    Why the study of solar eclipse is crucial?

    • One of the reasons that NASA studies solar eclipses is to study the top layer of the sun called the corona.
    • During an annular eclipse, NASA uses ground and space instruments to view this top layer when the sun’s glare is blocked by the moon.

    Back2Basics: Summer Solstice

    • The summer solstice occurs when one of the Earth’s poles has its maximum tilt toward the Sun.
    • It happens twice yearly, once in each hemisphere (Northern and Southern).
    • For that hemisphere, the summer solstice is when the Sun reaches its highest position in the sky and is the day with the longest period of daylight.
    • Within the Arctic circle (for the northern hemisphere) or Antarctic circle (for the southern hemisphere), there is continuous daylight around the summer solstice.
    • On the summer solstice, Earth’s maximum axial tilt toward the Sun is 23.44°. Likewise, the Sun’s declination from the celestial equator is 23.44°.

  • Revealing the secrets Arctic holds

    This article is about Polarstern, is an icebreaker, which traversed the Arctic Ocean to study the aspects related to ice there. Here, we will look at some of these aspects. These aspects are-monitoring of the ice, difficulty in measuring the thickness, rate of melting of ice and relations with cloud formation.

    Arctic: A recorder and driver of climate change

    How is it a recorder of climate change?

    • It is a recorder because of two co-related factors, these are-
    • 1) The visible difference between ice and water.
    • 2) The obvious relationship between global temperatures and the amount of ice around.
    • Two factors together shows in an easily graspable way how things are changing.
    • The extent of the Arctic sea ice in summer has declined by 30% in the past 30 years, and that loss is accelerating (see chart).

    How is it a driver of climate change?

    • The Arctic is also a driver of climate change, because the whiteness of ice means it reflects sunlight back into space, thus cooling Earth.
    • Whereas the darkness of open water means it absorbs that light.
    • The less of the reflection of sunlight and the more absorption of light will result in a faster rise in global temperatures.

    Monitoring the Arctic’s ice

    • At the moment this is monitored mainly by satellite.
    • Measuring the extent of the Arctic’s ice from space is easy.
    • Measuring its thickness is trickier.
    • From orbit, this is done by a mixture of radar and laser beam.
    • Icesat 2, an American craft, provides laser-altimeter data that record the height above sea level of the top of the snow that overlies the ice.
    •  Cryosat 2, a European one, uses radar to penetrate the snow and measure the height of the top of the ice itself.
    • The thickness of the ice in a particular place can then be calculated by applying Archimedes’ principle of floating bodies to the mixture of ice and snow, and subtracting the thickness of the snow.
    • But there is a view that the data collected by these two satellites may be inaccurate, leading to an overestimation of the ice’s thickness.

    Let’s understand why the data about thickness could be inaccurate

    • When all is working perfectly, the return signal for Cryosat 2 comes exactly from the boundary between the ice and any overlying snow.
    • But, that this is not always what happens.
    • Variables such as layering within the snow, along with its temperature and salinity, might affect the returning radar signal by changing the snow’s structure and density.
    • This could cause the signal to be reflected from inside the snow layer, rather than from the boundary where it meets the ice.
    • If that were happening, it would create the illusion that the ice beneath the snow is thicker than is actually the case.

    How topography of Arctic ice matters

    • Though sea ice is solid, it is not rigid.
    • It forms but a thin skin on the ocean—varying in depth from around 30cm in summer to a couple of metres in winter—so is readily moved by wind and current.
    • As the ice moves it stretches and cracks in some places.
    • Large cracks formed in this way are called leads, because they are wide enough to “lead” a ship.
    • In other places, by contrast, movement makes the ice thicker.
    • As individual panes of ice butt up against each other, they create ridges that can be metres high.
    •  But even from the ship’s deck one can watch leads opening and ridges forming around the vessel.
    • Observations suggest that winter the ice has been particularly mobile—and has thus become particularly rough, with a surprising number of ridges.

    So, how these ridges affect the rate at which ice melts?

    • These ridges may affect the rate at which the ice melts—but to complicate matters, this could happen in two opposing ways.
    • Ridges make ice thicker, and thicker ice melts more slowly.
    • On the other hand, a ridge projects down into the sea as well as up into the air (Archimedes, again), so it may stir up water from below the surface.
    • Deep water is warmer than the surface layer, so this stirring would serve to increase melt rates.
    • Moreover, to add to the confusion, ridges are prone to having pieces of ice fall off them into the sea, to form small blocks known as brash.
    • This brash, having more surface area per unit volume than unbroken ice, melts faster.

    How cloud formation is affected by cracks in Arctic ice

    • On most parts of Earth clouds form as droplets of water condense around “seeds” of dust or organic molecules.
    • In the Arctic, there is little dust.
    • Biological activity, too, is in short supply compared with elsewhere—and is, moreover, conducted mainly below the barrier of the sea ice.
    • It might, therefore, be expected that there would be few seeds present for clouds to form around.
    • And yet, clouds are present.
    • Cloud seeds there tended to be compounds containing sulphur, nitrogen, chlorine, bromine or iodine.
    • Presence of these molecules suggests their link with cracks in the ice sheets.
    • This means that more cracks in the ice sheet could lead to more clouds in the Arctic.
    • What overall effect that might have on the climate is unclear.
    • Summer clouds would reflect sunlight back into space, cooling the planet.
    • Those formed in winter, when the sun is below the horizon, would serve as insulation, warming it.
    •  Two opposite outcomes are possible—or perhaps the net effect will be that they cancel each other out.

    Conclusion

    Properly disentangling the interactions between Arctic ice, atmosphere and ocean life will require data collected across a full year—for the contrast between winter and summer at the poles is greater than anywhere else on the planet.

  • Kodumanal Megalithic Burial Site

    The Kodumanal excavation in Erode Dist. of Tamil Nadu has threw light on burial rituals and the concept of afterlife in megalithic culture.

    Must read:

    Chapter 1 | Stone Age – Paleolithic, Mesolithic and Neolithic

    About these sites

    • The researchers have identified 250 cairn-circles at the village in Erode district.
    • Earlier excavations revealed that the site served as a trade-cum-industrial centre from 5th century BCE to 1st century BCE.
    • The rectangular chambered cists, each two metres long and six metres wide, are made of stone slabs, and the entire grave is surrounded by boulders that form a circle.
    • The grave could be of a village head or the head of the community as the size of two boulders, each facing east and west, are bigger than other boulders.
    • Believing that the deceased person will get a new life after death, pots and bowls filled with grains were placed outside the chambers.

    What are Megaliths?

    • Megaliths are the earliest surviving man-made monuments we know of—derived from the Latin mega (large) and lith (stone).
    • Megaliths were constructed either as burial sites or commemorative (non-sepulchral) memorials.
    • The former are sites with actual burial remains, such as dolmenoid cists (box-shaped stone burial chambers), cairn circles (stone circles with defined peripheries) and capstones (distinctive mushroom-shaped burial chambers found mainly in Kerala).
    • The urn or the sarcophagus containing the mortal remains was usually made of terracotta.
    • Non-sepulchral megaliths include memorial sites such as menhirs. (The line separating the two is a bit blurry, since remains have been discovered underneath otherwise non-sepulchral sites, and vice versa.)
    • In India, archaeologists trace the majority of the megaliths to the Iron Age (1500 BC to 500 BC), though some sites precede the Iron Age, extending up to 2000 BC.

    Megaliths in India

    • Megaliths are spread across the Indian subcontinent, though the bulk of them are found in peninsular India, concentrated in the states of Maharashtra (mainly in Vidarbha), Karnataka, Tamil Nadu, Kerala, Andhra Pradesh and Telangana.
    • According to archaeologists around 2,200 megalithic sites can be found in peninsular India itself, most of them unexcavated.
    • Even today, a living megalithic culture endures among some tribes such as the Gonds of central India and the Khasis of Meghalaya.

    Literary sources

    • Megalithic culture finds several references in ancient Tamil Sangam literature. For instance, menhirs are referred to as nadukal.
    • Ancient Sangam texts lay out, in detail, a step-by-step procedure for laying a memorial stone or nadukal in honour of a fallen hero.
    • Manimekalai (5th century AD), the famous Sangam epic, refers to the various kinds of burials namely cremation (cuṭuvōr), post excarnation burial (iṭuvōr), burying the deceased in a pit (toṭukuḻip paṭuvōr), rock chamber or cist burial (tāḻvāyiṉ aṭaippōr), urn burial encapped with lid (tāḻiyiṟ kavippōr).
    • Even in the Sangam age (when kingship and a well-ordained society had emerged) the above modes of burials survived.

  • What is Axone?

    A movie named Axone — also spelt akhuni —soya bean dish of Nagaland has been recently released.

    The traditional ‘Axone’ dish is very unique in itself. However, one must note that it does NOT carry any GI tag. Still, there is a possibility of it being asked in match the pair type questions.

    What is Axone?

    • Axone — also spelt akhuni — is a fermented soya bean of Nagaland, known for its distinctive flavour and smell.
    • As much an ingredient as it is a condiment, Axone used to make pickles and chutneys, or curries of pork, fish, chicken, beef etc.
    • While it is called ‘axone’ in parts of Nagaland, fermented soya bean is cooked with, eaten and known by different names in different parts of Northeast India, including Meghalaya and Mizoram, Sikkim, Manipur as well in other South, Southeast and East Asian countries.
    • Axone is prepared and eaten across Nagaland but is particularly popular among the Sumi (also Sema) tribe. They use it in every meal.

  • “Assessment of Climate Change over the Indian Region” Report

    The Union Ministry of Earth Sciences (MoES) has released the “Assessment of Climate Change over the Indian Region” Report.

    This newscard discusses a very important concept: the Representative Concentration Pathway (RCP). Note its definition.  It can be directly asked as a statement based on prelims MCQ.

    Highlights of the report

    • Average surface air temperatures over India could rise by up to 4.4 degrees Celsius by the end of the century as compared to the period between 1976 and 2005, according to the MoES report.
    • The rise in temperatures will be even more pronounced in the Hindu Kush-Himalayan region where the average could reach 5.2°C.
    • The region is already highly vulnerable to climate-related variability in temperatures, rainfall and snowfall.
    • By 2100, the frequency of warm days and warm nights might also increase by 55 per cent and 70 per cent respectively, as compared to the period 1976-2005 under the RCP 8.5 scenario.
    • The incidences of heat waves over the country could also increase by three to four times. Their duration of occurrence might also increase which was already witnessed by the country in 2019.

    A 100-year record

    • Between 1900 and 2018, the average temperatures of India rose by 0.7°C.
    • This rise in temperatures has been largely attributed to global warming due to GHG emissions and land use and land cover changes.
    • But it has also been slightly reduced by the rising aerosol emissions in the atmosphere that have an overall cooling characteristic.
    • The report predicts that monsoon rainfall could change by an average of 14 per cent by 2100 that could go as high as 22.5 per cent.
    • The report does not mention if this change will be an increase or a decrease but still represents variability.
    • It further says that the overall rainfall during the monsoon season has decreased by six per cent between 1950 and 2015.

    Data on dry spells

    • The assessment also says that in the past few decades, there has been an increased frequency of dry spells during the monsoon season that has increased by 27 per cent between 1981-2011, as compared to 1951-1980.
    • The intensity of wet spells has also increased over the country, with central India receiving 75 per cent more extreme rainfall events between 1950 and 2015. This means that it either rains too little or too much.
    • One of the primary examples of this was the monsoon seasons of 2018 and 2019 where dry spells were broken by extremely heavy rainfall spells, creating a flood and drought cycle in many regions in India.

    What is Representative Concentration Pathway (RCP)?

    • A Representative Concentration Pathway (RCP) is a greenhouse gas concentration (not emissions) trajectory adopted by the IPCC.
    • It is defined as a radiative force in watt per square metre due to the rising greenhouse gas (GHG) emissions in the atmosphere.
    • Four pathways were used for climate modelling and research for the IPCC Fifth Assessment Report (AR5) in 2014.
    • The pathways describe different climate futures, all of which are considered possible depending on the volume of greenhouse gases (GHG) emitted in the years to come.
    • The RCPs – originally RCP2.6, RCP4.5, RCP6, and RCP8.5 – are labelled after a possible range of radiative forcing values in the year 2100 (2.6, 4.5, 6, and 8.5 W/m2, respectively).
    • Since AR5 the original pathways are being considered together with Shared Socioeconomic Pathways: as are new RCPs such as RCP1.9, RCP3.4 and RCP7.

  • When did CO2 become our planet’s arch enemy?

    Carbon dioxide was always essential for our planet. This newscard discusses when did it become too much.

    Try this question from CSP 2017:

    Q. In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be the potential sites for carbon sequestration?

    1. Abandoned and uneconomic coal seams
    2. Depleted oil and gas reservoirs
    3. Subterranean deep saline formations

    Select the correct answer using the code given below:

    (a) 1 and 2 only

    (b) 3 only

    (c) 1 and 3 only

    (d) 1, 2 and 3

    GHGs in atmosphere

    • The Earth’s atmosphere is made up of different gases. The temperature of the atmosphere depends on a balance between the incoming energy from the sun and the energy that bounces back into space.
    • Greenhouse gases (GHG) such as carbon dioxide (CO2), methane and nitrous oxide play an important role in the atmosphere.
    • They absorb some of the sun’s heat and release it back in all directions, including back to the atmosphere.
    • Through this process, CO2 and other GHGs keep the atmosphere warmer than it would be without them.
    • However, fossil fuel-run industries and other human activities add GHGs to the atmosphere. This, in turn, increases atmospheric temperature, causing global warming.

    Assessing the carbon level

    • In 1958, American scientist Charles David Keeling calculated the amount of CO2 in our atmosphere.
    • When he started his measurements in 1958, the CO2 levels were around 315 parts per million (PPM).
    • When he died in 2005, the project was taken over by his son Ralph Keeling. By 2014, CO2 levels had increased to about 400 PPM.
    • With his systematic study of atmospheric CO2, Keeling became the first person to alert the world about the increasing levels of CO2 in the atmosphere.

    Reasons for rising CO2 levels

    • Scientists first argued that the increasing release of methane and CO2 was due to agriculture and livestock.
    • But, with the start of the Industrial Revolution in the 18th century, the use of fossil fuels and CO2 levels rose simultaneously.
    • Nations that underwent the Industrial Revolution used huge amounts of fossil fuels and became centres of high CO2 emissions, while nations with an agrarian economy emitted less GHGs.
    • Over the years, as CO2 levels increased, it sparked off debates and arguments between the GHG-emitting rich industrial nations and the victims of global warming — the poorer nations.

  • Traditional art of Talamaddale

    The traditional art of ‘Talamaddale’, a variant of Yakshagana theatre, has gone virtual in times of COVID-19.

    Try this question from CSP 2017:

    Q.With reference to Manipuri Sankirtana, consider the following statements:

    1. It is a song and dance performance.
    2. Cymbals are the only musical instruments used in the performance.
    3. It is performed to narrate the life and deeds of Lord Krishna.

    Which of the statements given above is/are correct?

    (a) 1, 2 and 3.

    (b) 1 and 3 only

    (c) 2 and 3 only

    (d) 1 only

    Talamaddale theatre

    • Tala-Maddale is an ancient form of performance dialogue or debate performance in Southern India in the Karavali and Malnad regions of Karnataka and Kerala.
    • The plot and content of the conversation is drawn from popular mythology but the performance mainly consists of an impromptu debate between characters involving sarcasm, puns, philosophy positions and humour.
    • The main plot is sung from the same oral texts used for the Yakshgana form of dance- drama.
    • Performers claim that this was a more intellectual rendition of the dance during the monsoon season.

    How it is different from Yakshagana?

    • Unlike the Yakshagana performance, in the conventional ‘talamaddale,’ the artists sit across in a place without any costumes and engage in testing their oratory skills based on the episode chosen.
    • If music is common for both Yakshagana performance and ‘talamaddale’, the latter has only spoken word without any dance or costumes.
    • Hence it is an art form minus dance, costumes and stage conventions.
    • It has an ‘arthadhari’ who is an orator, a ‘bhagavatha’ (singer-cum-director), and a ‘maddale’ player.

    Back2Basics: Yakshagana

    • It is the oldest theatre form popular in Karnataka.
    • It emerged in the Vijayanagara Empire and was performed by Jakkula Varu
    • It is a descriptive dance drama.
    • It is presented from dusk to dawn.
    • The stories are drawn from Ramayana, Mahabharata and other epics from both Hindu and Jain tradition.

  • In news: Raja Parba Festival

    The Prime Minister has extended his greetings to the people of Odisha for the unique Raja Parba festival.

    Match the pair based question can be asked from festivals as such with pairs of name and celebrating state. Recently, the following festivals were also in the news: Ambubachi Mela, Thrisoor Puram, Meru Jatara, Nagoba Jatara etc.

    Also, note the similarities between the Raja Parba and Ambubachi Mela …

     About Raja Parba Festival

    • Raja Parba is Odisha’s three-day unique festival celebrating the onset of monsoon and the earth’s womanhood.
    • As a mark of respect towards the earth during her menstruation days, all agricultural works, like ploughing, sowing is suspended for the three days.
    • Raja Sankranti is the first day of the Ashara month.
    • It is celebrated on the day prior to the Sankranti, (Pahili Raja), the day of Sankranti, and the day after, known as Bhu Daha or ‘Basi Raja.
    • The festival is essentially the celebration of the earth’s womanhood.
    • It is believed that during this time the Mother Earth or Bhudevi undergoes menstruation.
    • The fourth day is the day of the ‘purification bath’.
    • As it is a celebration of womanhood, a lot of the focus is on young women, who wear new clothes, apply ‘Alata’ on their feet and enjoy folk songs while swinging on decorated rope swings.

     

  • Migrants and COVID

    In this Article, we highlight some facts about migration in India, summarize key relief measures announced by the government and directives issued by the Supreme Court for the migrant population in relation to the lockdown.
    ———————————————————————————
    Reference source: https://www.prsindia.org/theprsblog/migration-india-and-impact-lockdown-migrants

  • Lonar Lake colour changes to pink

    The colour of water in Maharashtra’s Lonar Lake, formed after a meteorite hit the Earth some 50,000 years ago, has changed to glaring.

    Make a note of all saltwater lakes in India. Few of them are Pulicat, Pangong Tso, Chilika, and Sambhar Lakes etc.

    About Lonar Lake

    • Lonar Lake, also known as Lonar crater, is a notified National Geo-heritage Monument, saline (pH of 10.5), Soda Lake, located at Lonar in Buldhana district, Maharashtra.
    • It was created by an asteroid collision with earth impact during the Pleistocene Epoch.
    • It is one of the four known, hyper-velocity, impact craters in basaltic rock anywhere on Earth.
    • It sits inside the Deccan Plateau—a massive plain of volcanic basalt rock created by eruptions some 65 million years ago.
    • Its location in this basalt field suggested to some geologists that it was a volcanic crater.

    Why there’s a color change?

    • The salinity and algae can be responsible for this change.
    • There is no oxygen below one meter of the lake’s water surface.
    • There is an example of a lake in Iran, where water becomes reddish due to increase in salinity.
    • The level of water in the Lonar Lake is currently low as compared to the few past years and there is no rain to pour fresh water in it.
    • The low level of water may lead to increased salinity and change in the behaviour of algae because of atmospheric changes.