UPSC CSE Prelims
Tides and Waves Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 4 — Rann of Kutch

The Rann of Kutch is the best example of repeated falls in sea level giving rise to extensive marshland. Geological evidence indicates that this vast salt marsh in Gujarat was once a shallow extension of the Arabian Sea, but tectonic movements and climatic changes led to repeated sea level recessions, depositing saline materials and creating the present-day seasonal marshland. During monsoons, it fills with water forming a shallow lake, and in summer, it dries into extensive white salt flats.

Why other options are incorrect:
Option 1 – Bhitarkanika Mangroves: This is a deltaic mangrove ecosystem in Odisha formed by river sediment deposition, not by repeated sea level falls.
Option 2 – Marakkanam Salt Pans: These are coastal salt production areas in Tamil Nadu, created through human intervention for salt extraction, not natural sea level regression.
Option 3 – Naupada Swamp: This is a freshwater wetland ecosystem in Andhra Pradesh, unrelated to sea level changes.

📝 Short Notes: Rann of Kutch Formation

• Location: Northwestern Gujarat, extending into Pakistan; part of the Thar Desert region
• Types: Great Rann (larger, northern) and Little Rann (smaller, southern)
• Geological History: Once part of the Arabian Sea; tectonic uplift and sea level fluctuations during Pleistocene era isolated it from the sea
• Seasonal Transformation: Flooded during monsoon (June-September); dries into salt-encrusted desert in summer
• Ecological Significance: Home to Wild Ass Sanctuary in Little Rann; breeding ground for flamingos; unique halophytic (salt-tolerant) vegetation
• Economic Importance: Major salt production area; traditional salt farming by Agariya community
• Cultural Heritage: Famous for Rann Utsav festival; traditional handicrafts of Kutchi communities

Detailed Explanation:

Answer: Option 3 — Chandipur

Chandipur Beach in Balasore district of Odisha is famous for its unique phenomenon where the sea recedes up to 2-5 kilometers during low tide, exposing the sea floor for several hours. This extraordinary tidal behavior occurs twice daily due to the beach's exceptionally shallow gradient and flat sea bed, allowing visitors to literally walk on the sea floor. The water returns during high tide, making it one of the most distinctive coastal features in India.

Detailed Explanation:

✅ Statement 1 – Correct: The Sun's gravitational force contributes to tidal generation, producing a tidal force approximately 46% as strong as the Moon's despite its greater mass but larger distance.

✅ Statement 2 – Correct: The Moon's gravitational pull is the primary cause of tides, creating a tidal bulge on the side of Earth facing the Moon due to stronger gravitational attraction on ocean water.

✅ Statement 3 – Correct: Centrifugal force from the Earth-Moon system's rotation around their common barycenter creates a second tidal bulge on the side of Earth opposite to the Moon.