Layers of the Earth and Plate Tectonics

🧱 1. Layers of the Earth

The Earth is made up of four main layers, each with different properties:

🟤 a) Crust

• Outermost layer

• Solid and relatively thin

• Includes continents and ocean floors

• Thickness: 5–70 km

• Broken into tectonic plates

🔥 b) Mantle

• Below the crust

• Solid rock that flows slowly like thick syrup

• Largest layer (about 2,900 km thick)

• Divided into upper and lower mantle

• Causes movement of tectonic plates due to convection currents

🟡 c) Outer Core

• Made of liquid iron and nickel

• Responsible for Earth's magnetic field

• Depth: ~2,200 km thick

⚫ d) Inner Core

• Solid due to extreme pressure

• Made mostly of iron and nickel

• Hottest layer: over 5,000°C

• Radius: about 1,220 km

🌐 2. Plate Tectonics

The Earth’s crust is divided into tectonic plates, which "float" on the slowly moving mantle beneath.

🌍 What Are Tectonic Plates?

• Giant slabs of solid rock (like puzzle pieces)

• About 15 major plates (e.g., Eurasian, Pacific, African plates)

• Move a few centimeters per year

🔄 3. Plate Boundaries and Movement

There are 3 main types of boundaries between plates:

🌋 4. What Happens Due to Plate Movement?

• Earthquakes: When plates grind or slip suddenly

• Volcanoes: When magma escapes through weak spots in crust

• Mountain Formation: When plates collide and push land upward

• Ocean Trenches: When one plate slides beneath another

🧪 5. How Do We Know This?

Scientists study:

• Seismic waves from earthquakes

• Volcanic activity and hotspots

• Fossils and rock patterns on different continents

• GPS measurements showing movement of plates

🌍 Summary Table

✅ Final Thought:

Earth may look solid, but it’s constantly changing.
Thanks to plate tectonics, we have continents, oceans, mountains, and earthquakes. Understanding these natural processes helps us prepare for natural disasters and learn more about our planet’s history.