Current Affairs – May 28, 2024

{GS1 – Geo – PG – Geomorphology} Earth’s mysterious D” layer

Context (Phys): Deep within Earth, there lies a mysterious layer called the D” layer.

Credits: Spring8

Located roughly 3,000 kilometres down, this zone sits just above the boundary between the planet’s molten outer core and its solid mantle.
Theory relying on the Giant Impact hypothesis believes the D” layer may be a unique composition leftover from this colossal impact, potentially holding clues to Earth’s formation.

The giant Impact hypothesis proposes a Mars-sized object slammed into the proto-Earth, creating a planet-wide magma ocean in the aftermath.

The D” layer is not perfectly sphere and is surprisingly patchy. Its thickness varies greatly from place to place, with some regions even lacking a D” layer altogether.
The D” layer may also be where deep mantle plumes originate and where subducting slabs terminate.
The new research highlights the presence of a substantial amount of water within this global magma ocean. The exact origin of this water remains a topic of debate.
Some suggest that water would have concentrated towards the bottom of the magma ocean as it cooled, forming hydrous oceans. This hydrous magma ocean favoured the formation of an iron-rich phase called iron-magnesium peroxide.
The presence of this iron-rich peroxide phase would alter the mineral composition of the D” layer, deviating from our current understanding.
According to the new model, minerals in D” would be dominated by a new assemblage: the iron-poor silicate, iron-rich (Fe, Mg) peroxide, and iron-poor (Fe, Mg) oxide.
This iron-dominant peroxide also possesses low seismic velocities and high electrical conductivity, making it a potential candidate to explain the D” layer’s unique geophysical features.

The D” layer consists of ultra-low velocity zones (ULVZ) and layers of high conductance, both of which contribute to its well-known compositional heterogeneity.

{GS2 – IR – Israel-Palestine} ICJ ruling on Israel’s Rafah offensive **

Context (TH): ICJ has asked Israel to stop its military offensive in the southern Gaza city of Rafah.

It can further Israel’s international isolation and escalate demands for a ceasefire.
ICJ revised its order on South Africa’s latest request, arguing that provisional measures are not sufficient.

Change in the situation

As per Article 76 of the Rules of Court (1978), the Court has the power to “revoke or modify” any decision concerning provisional measures on account of “change in the situation”.
ICJ observed that the “repeated large-scale displacement of the already extremely vulnerable Palestinian population” constitutes “a change in the situation”.
- United Nations Children’s Fund (UNICEF) had indicated that half of the approximately 1.2 million Palestinians sheltering in Rafah were children and that Israel’s hostilities could result in the destruction of “the few remaining basic services and infrastructure.”
- The World Food Programme (WFP) was unable to access its warehouse in the region, leading to a disastrous hunger crisis.
The ICJ relied upon a host of UN reports to underscore the “immense risks” associated with Israel’s continuous military strikes in Rafah.
It also highlighted the inability of Israel to supply sufficient humanitarian aid.

Implications

Since the ICJ lacks any direct enforcement mechanisms, only the UN Security Council’s willingness to act can help. However, the US veto has repeatedly helped Israel.
Israel has interpreted the order as a “limited order” that instructs it to abide by the Genocide Convention but does not require it to halt the Rafah offensive.

{GS3 – Envi – Degradation} Speedy melting of Doomsday glacier **

Context (OL): A study has unveiled a concerning revelation about Antarctica’s infamous “Doomsday Glacier,” shedding light on its vulnerability to the warming oceans.

Doomsday glacier

Antarctica’s Thwaites Glacier, roughly the size of Britain, is a fast-moving glacier in West Antarctica.
Because of the risk it faces — and poses — Thwaites is often called the Doomsday Glacier. Because of its size (1.9 lakh square km), it contains enough water to raise the sea level by more than half a metre.
Thwaites’s melting already contributes 4% to global sea level rise each year.
Thwaites are important for Antarctica as it slows the ice behind it from freely flowing into the ocean.

Credits: BBC

Vigorous melting

Salty and relatively warm ocean water is infiltrating beneath Thwaites Glacier, leading to significantly speedy melting. This process, termed as “vigorous melting“, is eroding its stability.
However, its potential collapse could lead to a staggering 10-foot rise in sea levels, posing a dire threat to coastal communities worldwide.
Previous studies discovered a deep connection to the east through which deep water flows from Pine Island Bay. That study also attributed the melting to the heat transport caused by channels bringing warm water towards the glacier from the north.
With melting, glaciers become light and float off the land where they used to be situated. The resulting retreating grounding line exposes more of a glacier’s base to seawater, increasing the risk of melting.
Since the late 1990s, the glacier has seen a 14km retreat of its “grounding line.”

The grounding line is the point where the ice flowing off the land and along the seabed floats up to form a huge platform.

{GS3 – Envi – Species} Proboscis monkeys (Nasalis larvatus) *

Context (DTE): Nasalis larvatus monkey is a topic of study for its large, bizarre nose.

One of the largest monkey species in Asia, Proboscis monkeys are endemic to the island of Borneo.

Credits: DTE

Nose: A status symbol

Unique nose: Enormous, pendant, tongue-shaped noses of adult males; those of juveniles and females are shorter and upturned.
The monkey’s enormous nose, along with its pink face and rotund belly, led people in the Indonesian half of Borneo to call them ‘Dutchman monkeys’.
Social groups tend to be large-nosed male-led harems of 6-16 individuals. Neighbouring groups sometimes meet and eat together.
These older, dominant and large-nosed males don’t easily tolerate other large-nosed males, often trying to ward them off aggressively with deep honks and “nasal roars”.
Young adult males with smaller noses often live in all-male bachelor groups and don’t tend to fight aggressively with each other. Bachelor males on getting older and large (and large-nosed) enough to compete with males that are part of a breeding group.

Evolution of large nose

The bony chamber of the skull sits behind the fleshy nose.
Previous research that looked at the bulbous nose in males suggests it evolved to advertise status.
A new study has linked the shape of the nose to “honks”, the roar sounds. Male nasal cavities were low and long compared to females.
This allows males to build up resonance (sound vibration) in their nasal cavities, allowing them to emit deeper and louder calls through their noses.
Nasal aperture shape in males resembles eggplant, while in females, it resembles upside-down pear.
This further supports the idea that the nasal cavity of male proboscis monkeys underwent an evolutionary change for the purpose of making certain sounds.

Other physical properties and behaviour

Habitat: Coastal mangroves, peat swamps and riverine forests.
Conservation status: IUCN – EN, CITES – Appendix I.
The male sexual organ is permanently erect. The pelt is greyish-white ventrally and reddish dorsally.
Sexual dimorphism is pronounced in body size and nose shape. Males are heavier. Babies are dark-furred with a bluish face.
Strongly arboreal and Folivorous (favourite diet is leaves).
They can swim quite well and have webbed fingers and toes.

{GS3 – IE – Fisheries} Underutilised mesopelagic resources *

Context (TH): Marine fishery experts stressed the need to explore the potential of underutilised mesopelagic resources within the Indian Exclusive Economic Zone.

Credit: Thoughtco

Mesopelagic Zone

Mesopelagic zone: 200 to 1,000 metres below sea level. It is referred to as the twilight zone or the midwater zone, as sunlight this deep is very faint.
Temperature changes the greatest in this zone as this is the zone that contains the thermocline.
Because of the lack of light, it is within this zone that bioluminescence begins to appear in life.
Animals that live in the mesopelagic zone: Fish, shrimp, squid, snipe eels, jellyfish, and zooplankton.
- Home to many small fishes, including lantern fishes. These fishes are the most abundant vertebrates globally and are underutilised.
Light, oxygen, and temperature decrease with depth while salinity and pressure increase. Due to these conditions, little resources for food are available in the mesopelagic zone.

Resource Potential

Good source of protein, lipids, and minerals. High lipid content: Not used for direct human consumption.
Potential uses: Fishmeal industry for poultry and animal feed, and crop fertilisers.

The Meenakumari committee report is related to deep-sea fishing policy and guidelines.

{GS3 – IE – Securities} Adani Ports to enter Sensex *

Context (IE): Adani Ports and Special Economic Zone Ltd (APSEZ) will join Sensex at the Bombay Stock Exchange (BSE) on June 24, replacing Wipro.
APSEZ and Adani Enterprises are already part of Nifty on the National Stock Exchange (NSE).
Background: The announcement has come months after allegations by Hindenburg Research of stock manipulation and accounting fraud against Adani Group. It led to a 30-80% crash in their share prices.

Nifty vs Sensex

	Sensex (BSE)	Nifty 50 (NSE)
Number of Stocks	30 companies.	50 companies.
Launch	1986, (Oldest).	November 1995.
Market Capitalisation	Rs 419.99 lakh crore (as of May 24).	Rs 416.04 lakh crore (as of May 24).
Major Companies	Reliance Industries, ICICI Bank, and ITC Ltd.	Adani Enterprises, Bajaj Finance, and Coal India.

How Are Companies Selected in Sensex?

Must have a listing history of at least six months at BSE.
Must have traded every day during the six-month reference period.
Must have a derivative contract.
Must be among the top 75 companies based on their average three-month total market cap.
Liquidity assessed by average daily value traded (ADVT).Companies with ADVT weight greater than 98% are excluded.
After meeting the market cap and liquidity criteria, it should have a minimum free-float market cap of 0.50%.

A derivative is a financial instrument whose value is based on the value of an underlying asset, like equities and currency.

{GS3 – IE – Trade} India’s Trade Deficit and Surplus Overview 2023-24 *

Context (TH): India recorded a trade deficit with nine of its top 10 trading partners in 2023-24.

Credit: Reddit

Trade Statistics

Deficit increased countries (Compared to 2022-23): China: $85 billion ($83.2 billion), Russia: $57.2 billion ($43 billion), Korea: $14.71 billion ($14.57 billion), Hong Kong: $12.2 billion ( $8.38 billion).
Deficit decreased countries: UAE, Saudi Arabia, Russia, Indonesia, and Iraq.
Top Trading Partners: China is the largest trading partner: $118.4 billion in 2023-24.
- The U.S. was the top partner in 2021-22 and 2022-23.
- Bilateral trade with the U.S.: $118.28 billion in 2023-24.
Trade Surplus: India has a trade surplus of $36.74 billion with the U.S. in 2023-24. Surplus also with the U.K., Belgium, Italy, France, and Bangladesh.
Total Trade Deficit: Reduced to $238.3 billion in 2023-24 from $264.9 billion in the previous fiscal year.
India has a free trade agreement with four of its top trading partners: Singapore, the UAE, Korea, and Indonesia.

Economic Implications

Deficits from importing raw materials or intermediates can boost manufacturing and exports.
It can cause currency depreciation and increase external debt.
Expert Views: Bilateral trade deficit is not a major issue unless it leads to over-reliance on critical supplies.

Way forward

Solutions: Boosting exports, reducing unnecessary imports, developing domestic industries, and managing currency and debt levels effectively.

{GS3 – S&T – Space} Zero Debris Charter

Context (Phys): Twelve nations have signed the Zero Debris Charter at the ESA/EU Space Council, solidifying their commitment to the long-term sustainability of human activities in Earth orbit.
The 12 nations are: Austria, Belgium, Cyprus, Estonia, Germany, Lithuania, Poland, Portugal, Romania, Slovakia, Sweden and the United Kingdom. In addition, the European Space Agency (ESA) also signed the Charter as an International Organisation.
The Charter is a broader community-driven and community-building initiative for the global space community. It is an effort to become debris-neutral in space by 2030.
Need for the charter: Currently, more than one million pieces of space debris larger than one cm are in Earth orbit, capable of causing catastrophic damage to space assets and astronauts and could render some orbits entirely unusable.
While the charter is a non-legally binding agreement, it fosters a community of proactive actors working collectively to achieve space safety and sustainability with jointly defined measurable targets for 2030.

Other efforts to deal with space debris

UN Committee on the Peaceful Uses of Outer Space: States and organizations exchange their debris information to the Committee’s Scientific & Technical Subcommittee.
Convention on International Liability for Damage Caused by Space Objects 1972: It ensures International 3rd party liability.
Convention on Registration of Objects Launched into Outer Space, 1976: It mandates registration of space objects.
Space Debris Mitigation Guidelines, drafted by the Committee on the Peaceful Uses of Outer Space (COPUOS), 2007: These guidelines are non-binding and aim to limit the generation of new space debris.
NASA Orbital Debris Program: It officially began in 1979. The program looks for ways to create less orbital debris and designs equipment to track and remove the debris already in space.
Japan’s Adras-J, or Active Debris Removal by Astroscale, is testing its ELISA system for capturing debris with magnets.
British Remove DEBRIS Project is experimenting with nets & harpoons.
European Space Agency launched Clear Space – 1 to remove debris from the orbit.

India’s efforts

Network for Space Objects Tracking and Analysis (NETRA Project): It tracks space debris within 1,500 km with an optical telescope for surveillance.
Multi Object Tracking Radar: MOTR is developed by Satish Dhawan Space Centre allowing ISRO to track 10 objects simultaneously, including space assets & debris.
ISRO is part of the Inter-Agency Space Debris Coordination Committee to coordinate global efforts to reduce man-made and natural space debris by identifying debris mitigation options.

Learn in detail about Space Debris.

{GS3 – S&T – Tech} Copper’s enhanced hardness under extreme strain *

Context (TH): Researchers from MIT and Northwestern University found that pure copper, when heated and subjected to extreme strain, behaves like a harder material.
The new study shows the change in material strength response above 1 million /s strain rate.

Strain: Deformation of material under stress.
Strain rate: Rate at which strain changes, measured per second.

Experimental Method & Findings

In their study, the researchers accelerated aluminium oxide microparticles using lasers and shot them at a copper substrate at around 860 km/hr.
Findings: When the temperature of the copper object was increased while the strain rate was 10 million /s, copper behaved like a harder material at impact spots. At strain rates lower than 1 million /s, the copper became softer.
- Comparison with Steel: At 10 million/s strain rate and 177º C, copper strength is over 300 megapascal (MPa). Comparable to the conventional strength of 304 stainless steel at the same 177º C.
- The researchers also reported similar effects with pure titanium and gold.

Basics: Metals become softer when heated and strained at certain rates (0.000001/s and 10,000/s).
SAE 304 steel is the most common form of stainless steel today.

Applications

Potential new strategies for designing devices for extreme conditions.
Relevant for high-speed manufacturing and aerospace engineering.

Copper

It is a good conductor of electricity and is ductile [able to be drawn out into a thin wire].
Alloys of Copper
- Iron + chromium + nickel with carbon +silicon + manganese = Stainless Steel.
- Copper + Nickel == Morel Metal.
- Copper + Aluminium == Duralumin.
- Copper + Zinc == Brass.
- Copper + Tin == Bronze.
Copper ore is found in ancient as well as in younger rock formations.
Mining for copper is costly because most of the copper ores contain a small percentage of the metal.
India has low-grade copper ore (less than 1% metal content, international average 2.5%).
The major part of supply comes from the USA, Canada, Zimbabwe, Japan and Mexico.

Stone Age to Metal Age: Evolution of Metals

End of Stone Age: Copper smelting and alloying. Introduced metalworking, better agricultural tools, culture, trade, governments, and new weapons.
Iron Age: Iron replaced copper and tin.
- Steel is made by adding carbon to iron. Iron’s unique property is that it dissolves carbon. Repeated heating and cooling with carbon produces steel, a hard iron-carbon alloy.
- Impact of Steel: Harder than copper, tin, or iron.

{GS3 – S&T– Space} Planetary Alignment

Context (IE): Planet parade, also known as Planetary Alignment, is set to take place on June 3.

Credit: India Today

Planetary alignment refers to the rare positioning of planets in the solar system when all the planets appear close to the sun in a straight line or in a ‘planetary parade’.
However, actually, they only appear to be in a single line with no true orbital alignment. Some planets would be a little above and below others; hence, due to their positions, they will look aligned.

{Prelims – Envi – Species} Eucalyptus Tree

Context (TH): The Kerala government issued an order allowing the Kerala Forest Development Corporation (KFDC) to plant eucalyptus trees for its financial sustenance in 2024-2025.

As per the 2021 Kerala’s eco-restoration policy, its cultivation (including acacia and wattle) is not suitable for the environment as it results in “depletion of natural forests.”
Activists alleged that permitting the planting of eucalyptus trees contravened the policy’s aspirations and undermined efforts to beat back invasive species and mitigate human-animal conflicts.

About Eucalyptus tree

Eucalyptus trees, also known as gum trees, nilgiri trees, or safeda, are species of large flowering trees and shrubs with aromatic leaves and attractive smooth peeling bark.
These trees are native to Australia and Tasmania. In India, it was first planted around 1790 by the ruler of Mysore, Tipu Sultan, in his palace garden near Bangalore.

Uses of eucalyptus trees

Eucalyptus wood is hard and difficult to bend, making it ideal for flat furniture.
Since the wood is heavy, it is, therefore, good as firewood and for making charcoal.

Criticism of Eucalyptus

The ban on eucalyptus has emerged as part of the campaign against invasive species.
Eucalyptus is water-intensive and reduces available water for other species by effectively out-competing them.
In arid areas, it consequently suppresses different plant life, coupled with high water demand, reduces soil moisture, prevents groundwater recharge, and can reduce local water tables. This is worsened by a high transpiration rate indicative of the inefficient use of water.
Eucalyptus does not promote the building of humus. It does not contribute to the soil’s long-term fertility resulting in an overall nutrient impoverishment of the soil.
Eucalyptus is toxic due to its allelopathic properties, which reduce other plant life by restricting germination of other species and is also detrimental to soil micro and macrofauna.

Allelopathic species suppress their progeny and other plant life by leaching chemical inhibitors from the trees’ roots or litter.

{Prelims – Envi – Species} Markhor (Capra falconeri)

Context (DTE): The UN declared May 24 as the ‘International Day of the Markhor’.

Credit: iNaturalist

The Markhor, also known as screw horn goat, is the largest wild goat in the world. It is the national animal of Pakistan.
Distribution: It ranges over the north-western parts of the Hindu Kush Himalayas, in Uzbekistan, Turkmenistan, Tajikistan, Afghanistan, Pakistan and India.
- In India, the subspecies is found only in Jammu and Kashmir (J&K).
Habitat: They are adapted to mountainous terrain between 600 m and 3600 m elevation and are strongly associated with scrub forests dominated by oaks, pines, and junipers.
Physical description: The coat is of light brown to black colour and is smooth and short in summer while growing longer and thicker in winter. Both sexes posses extremely bold, flared, corkscrew-like horns which twist outwards.
They are skilled climbers and can scale steep rocky terrain to escape predators such as snow leopards and wolves.
Conservation Status: IUCN: Near Threatened | WPA, 1972: Schedule I | CITES: Appendix I
Threats: Illegal hunting, poaching, habitat loss, climate change.

{Prelims – Envi – Species} Oedocladium sahyadricum (Algae)

Context (TH): Phycologists at Catholicate College, Pathanamthitta, Kerala, found a new algal species. The new species is named Oedocladium sahyadricum. Sahyadricum refers to the Western Ghats.
Western Ghats provide ideal conditions for the growth of terrestrial microalgae.

Phycology is the branch of science that deals with the study of algae.

About Oedocladium sahyadricum

Features: Dioecious and terrestrial, with a superior operculum, ellipsoid oogonium, and oospore.
- Dioecious: Having the male and female reproductive organs in separate individuals.
- Operculum: It is a cap-like structure in some flowering plants, mosses, and fungi.
- Oogonium: The female sex organ of certain algae and fungi.
- Oospore: It forms when an oogonium (female gamete) is fertilised by a male gamete nucleus.
Appearance: Found as a thin mat of elongated strands on damp soil, velvety green turning yellowish-green as it matures.
Climatic conditions: Abundant growth likely needs rainy weather.
Potential Applications: Potential uses in medicine, agriculture, and the production of astaxanthin, a natural pigment with health benefits.
Economic Importance: Algae are used in high-value products & wastewater treatment.

{Prelims – In News} Zimbabwe’s Currency – ZiG

Context (TH | IE): The Reserve Bank of Zimbabwe (RBZ) has launched a new gold-backed currency called the ZiG, short for Zimbabwe Gold, replacing the Zimbabwean dollar.

It aims to provide stability and restore confidence in the country’s financial system after years of crippling hyperinflation (500% in recent years) and exchange rate volatility.
ZiG notes and coins will be available and issued in denominations: 1ZiG, 2ZiG, 5ZiG, 10ZiG, 20Zig, 50ZiG, 100ZiG, and 200ZiG.