31 March 2026

1. Honshu Island

Ø News:    A magnitude 6.2 earthquake recently struck off the eastern coast of Honshu, the largest island of Japan.

Ø  Identity and Location:

o Honshu, historically known as Akitsushima, is the largest among the four main islands of Japan.

o It is situated between the Pacific Ocean to the east and the Sea of Japan to the west.

o It is the seventh-largest island in the world.

Ø Major Cities: The island hosts many of Japan’s major cities, including Tokyo, Osaka, Hiroshima, Nagoya, Kyoto, and Yokohama.

Ø Physical Features

o Mount Fuji, located on Honshu, is the highest mountain in Japan.

o Lake Biwa, also located on Honshu, is the largest lake in Japan.

2. Sonowal Kacharis

Ø News:    A recent study has documented 39 plant species used by the Sonowal Kachari community for treating ailments such as fever, cough, kidney stones, and skin diseases.

Ø  Identity and Distribution:

o The Sonowal Kacharis are an indigenous community residing in northeastern India.

o A majority of their population lives in Assam, where they are the third-largest plain tribe and among the oldest tribal groups.

o Smaller populations are also found in Arunachal Pradesh and Meghalaya.

Ø Legal Status: They are recognised as a Scheduled Tribe under the Plains category in Assam.

Ø Ethnic Origin: The community is of Mongoloid origin.

Ø Language:

o Linguistically, they belong to the Tibeto-Burman language family.

o Assamese is their primary language.

o Many members also speak Hindi to communicate with people outside their community.

Ø Etymology: The term Sonowal is derived from a word meaning gold.

Ø Traditional Occupation: Historically, they were engaged in gold panning during the Ahom kingdom.

Ø Present Occupation: At present, the community is mainly dependent on agriculture.

Ø Crops Cultivated: They cultivate crops such as rice, betel nut, sweet potatoes, and cotton.

Ø Indigenous Medicine:

o The Sonowal Kacharis possess rich traditional knowledge related to indigenous medicinal practices.

o They use a variety of plant-based remedies for treating different health conditions.

Ø Religious Practices: The community follows Hinduism that is strongly influenced by folk traditions.

Ø Principal Deity: They regard Lord Shiva as their primary deity.

UPSC GS 3

3. Neoloboptera Peninsularis

Ø News:   Researchers from the Zoological Survey of India have discovered a new cockroach species named Neoloboptera peninsularis in the Deccan Peninsula.

Ø  Nature of the Species: It is a newly identified species of cockroach.

Ø Discovery Location:

o The species was found in the Deccan Peninsula near Pune in Maharashtra.

o It was located among palm shrubs and dry leaf litter near farmland in Nathachiwadi.

Ø Naming: The name peninsularis reflects its origin in Peninsular India.

Ø Scientific Significance:

o This discovery represents the first use of modern DNA-based techniques in India for identifying a cockroach species.

o It is the third known species of the genus Neoloboptera recorded in India.

o The other two species are Neoloboptera indica described in 1865 and Neoloboptera chakrabortyi described in 1995, with no new specimen-based records reported since then.

Ø Distinctive Features:

o It has asymmetrical cerci, which are paired appendages at the rear of the body.

o The species also shows a uniquely structured, whip-like male genital component.

4. Waste Foundry Sand

Ø News:   The Institute of Indian Foundrymen and the CSIR Central Road Research Institute have signed an agreement to develop and promote the use of waste foundry sand in road construction.

Ø Definition and Source: Waste foundry sand is a byproduct generated during the production of ferrous and non-ferrous metal castings.

Ø Composition: It primarily consists of high-quality silica sand.

Ø Variable Characteristics: Its physical and chemical properties vary depending on the casting process used and the type of industry generating it.

Ø Classification of Foundry Sand:

Ø Basis of Classification: Foundry sands are classified according to the type of binder systems used in metal casting.

Ø Types of Binder Systems: Two main types of binder systems are used, leading to two categories of foundry sand.

Ø Clay-Bonded Sand (Green Sand):

o This type is made from naturally occurring materials blended together.

o It typically contains 85 to 95 percent high-quality silica sand.

o It also includes 4 to 10 percent bentonite clay, which acts as a binding agent.

Ø Chemically Bonded Sand:

o This type is used in core making where high strength is required to withstand the heat of molten metal.

o It is also used in mould making processes.

Ø Waste Generation: Large quantities of waste foundry sand are produced, creating disposal challenges.

Ø Environmental Impact: Improper disposal can lead to environmental issues due to accumulation of industrial waste.

5. Euthalia Zubeengargi

Ø News:    A new butterfly species named Euthalia zubeengargi has recently been recorded in Arunachal Pradesh.

Ø Discovery and Classification:

o Euthalia zubeengargi is a newly identified butterfly species from Arunachal Pradesh.

o It belongs to the genus Euthalia, which is widely distributed across South and Southeast Asia.

Ø Natural Habitat:

o The species inhabits semi-evergreen forests.

o It is typically found at elevations ranging from 600 to 750 metres.

Ø Habitat Preference: It prefers cool and shaded interiors of forest ecosystems.

Ø Morphological Traits:

o Butterflies of this genus generally possess earthy brown wings.

o Their wings are marked with pale spots.

o They are commonly observed in forested environments.

Ø Feeding Behaviour:

o The butterfly has been observed resting on low vegetation.

o It feeds on tree sap and also collects minerals from damp surfaces near streams.

Ø Activity Pattern:

o It is mainly active from late morning to early afternoon.

o It makes short and slow flights between nearby plants.

Ø Species Richness:

o Euthalia zubeengargi is among more than 80 species of this genus recorded in the northeastern region of India.

Ø Environmental Indicators:

o Butterflies serve as important indicators of environmental health.

o Their presence, abundance, and diversity reflect the condition of ecosystems.

6. SWOT Satellite

Ø News:    NASA has recently developed a new map of the ocean floor using satellite data from the SWOT mission.

Ø Launch and Collaboration:

o The Surface Water and Ocean Topography satellite was launched in 2022.

o It is a joint mission between NASA and CNES.

Ø Objective: The mission aims to collect detailed observations of how Earth’s water bodies change over time.

Ø Measurement Technology:

o The satellite uses a specialised instrument known as the Ka-band Radar Interferometer.

o This instrument measures the height, width, and elevation of surface water bodies such as rivers, lakes, reservoirs, and oceans.

Ø High Resolution Mapping:

o It achieves high spatial resolution by sending microwave signals to water surfaces and analysing the time taken for their return.

o This enables tracking of dynamic changes in water movement.

Ø Flood Monitoring Capability: The satellite is capable of observing more than 55 percent of large-scale global floods throughout their lifecycle due to its frequent orbital coverage.

Ø Global Coverage:  SWOT orbits the Earth in such a way that it can scan around 90 percent of the planet every 21 days.

Ø Observation of Inland Water Bodies:

o It can monitor nearly all rivers wider than 330 feet.

o It also observes more than one million lakes and reservoirs that are larger than 5 acres.

Ø Oceanographic Significance:

o The satellite can detect subtle variations in sea surface elevation associated with small currents and eddies.

o These features play an important role in the ocean’s absorption and redistribution of heat and carbon.