🌏 पृथ्वी की प्लेट गति का रहस्य | UPSC/IAS भूगोल ~ Pro. Purushottam Meghwal

🌏 पृथ्वी की प्लेट गति का रहस्य | UPSC/IAS भूगोल
Meghwal's IAS Address: HIG R-6, E-6 Arera Colony Near Sai Board, Arera Colony, Bhopal, Madhya Pradesh 462016 Phone: [phone]
/ purushottammeghwalbhopal
Website - www.meghwalsias.com
Official Telegram channel
t.me/meghwalsias
🌍 Earth's Structural Movements | Complete Geography for UPSC CSE/IAS 2025
A comprehensive lecture covering Earth's structural movements, including:
Continental Drift Theory
Plate Tectonics
Sea Floor Spreading
Types of Mountains and Faults
📖 Key Concepts:
Wegener's Continental Drift Theory
Evidence for Continental Drift
Harry Hess's Sea Floor Spreading
Major and Minor Tectonic Plates
Types of Plate Movements
Mountain Formation Processes
Fault Types and Their Effects
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📚 EARTHQUAKES & SEISMIC WAVES
🎯 Key Highlights:
Complete conceptual clarity
Latest examples including Turkey-Syria (2023) & Morocco (2023) earthquakes
Important facts and figures for Prelims
Answer writing tips for Mains
Previous years' questions analysis
📝 Important Topics:
Body Waves vs Surface Waves
P-waves and S-waves
Shadow Zone formation
Richter Scale vs Mercalli Scale
Seismograph working
Distribution of earthquakes
Impact assessment
Disaster management
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🌋 VOLCANIC & INTRUSIVE FEATURES
✨ Part 1: VOLCANO-ASSOCIATED FEATURES
Hot Springs Formation & Examples (Tattapani, Manikaran)
Geysers (Old Faithful, Formation Process)
Fumaroles - Steam & Gas Vents
Mud Volcanoes - Unique Formations
Special Focus on Indian Examples
✨ Part 2: INTRUSIVE LANDFORMS
Batholith - Massive Underground Structures
Laccolith - Mushroom-shaped Formations
Lopolith - Saucer-shaped Depressions
Sills & Dykes - Horizontal & Vertical Intrusions
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VOLCANISM: FORMATION, PROCESSES & IMPACTS
DEFINITION
Volcanism refers to all processes involving the transfer of magma and volcanic gases from Earth's interior to its surface.
STEP-BY-STEP PROCESS
A) MAGMA GENERATION
Temperature and pressure changes in mantle/crust
Three main mechanisms:
1.Decompression melting (at divergent boundaries)
2.Flux melting (at subduction zones)
3.Heat-driven melting (at hotspots)
B) MAGMA INTRUSION
Movement through weaknesses in crust
Formation of magma chambers
Key features:
• Dykes (vertical intrusions)
• Sills (horizontal intrusions)
• Batholiths (large intrusive bodies)
C) MAGMA EXTRUSION
Final stage of volcanic process
Transformation of magma to lava
Various types of eruptions:
1.Effusive (gentle flowing)
2.Explosive (violent ejection)
MAGMA VS LAVA
MAGMA:
Below Earth's surface
Contains dissolved gases
Temperature: 700-1300°C
Components:
• Liquid rock material
• Dissolved gases
• Crystal fragments
LAVA:
On Earth's surface
Most gases escaped
Cools and solidifies
Forms different structures:
• Pillow lavas
• Aa lava
• Pahoehoe lava
PYROCLASTIC FLOWS
Definition:
High-speed mixtures of:
• Hot gases
• Rock fragments
• Volcanic ash
Characteristics:
Temperatures up to 700°C
Speeds up to 700 km/h
Extremely destructive
Recent Example:
2021 Mount Semeru eruption, Indonesia
Caused devastating pyroclastic flows
LANDFORM FORMATION
A) INTRUSIVE LANDFORMS
(Cooling within crust)
1.Batholith
2.Laccoliths
3.Sills
4.Dykes
B) EXTRUSIVE LANDFORMS
(Cooling on surface)
1.Volcanic cones
2.Lava plateaus
3.Volcanic plugs
4.Calderas
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CURRENT AFFAIRS & EXAMPLES
Recent Volcanic Events:
1.Tonga Eruption (2022)
World's most powerful eruption in 30 years
Generated tsunami waves
Global atmospheric impacts
2.La Palma Eruption (2021)
Cumbre Vieja volcano
Lasted 85 days
Significant property damage
3.Mount Sinabung (Indonesia)
Frequent eruptions
Major agricultural impacts
Ongoing monitoring
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Volcanic Cones and Formations
1. Volcanic Cones
A. Shield Volcanoes
Gentle slopes, basaltic lava, non-explosive eruptions.
Examples: Mauna Loa, Kilauea (Hawaii).
B. Ash Cinder Volcanoes
Steep slopes, small size, formed from pyroclastic materials.
Examples: Taal (Philippines), Paricutin (Mexico).
C. Composite Volcanoes (Stratovolcanoes)
Steep-sided, alternating layers of lava and ash, andesitic magma.
Examples: Mount St. Helens (USA), Mount Fuji (Japan).
2. Volcanic Depressions
A. Craters
Circular summit depressions, formed by explosive eruptions.
B. Calderas
Large craters formed by cone collapse, often water-filled.
Examples: Lake Toba (Indonesia), Yellowstone (USA).
3. Flood Basalt Provinces
A. Deccan Traps (India)
Large lava plateau, ~66 million years old, fertile soil, groundwater resources.
B. Siberian Traps (Russia)
World's largest flood basalt province, linked to Permian extinction.
#UPSC2025Geography #Volcanism #PlateTectonics #Earthquakes #IAS