Exploring the Earth's Layers

• Earth's layers hold secrets that scientists use different methods to explore

Introduction to Earth's Layers

• Earth consists of distinct layers
• Each layer has a different composition and physical properties
• Understanding Earth's layers aids in grasping its dynamics

Overview of Earth's Layers

• The layers include, from outermost to innermost: crust, mantle, outer core, and inner core
• The crust is the outermost solid layer of the Earth
• The mantle is a thick, mostly solid layer
• The outer core is a liquid layer made up of iron and nickel
• The inner core is a solid, dense sphere

Earth's Crust

• Earth's crust is the outermost layer
• It is thin and rigid
• Oceanic and continental crust differ in thickness and composition
• Oceanic crust is thinner, denser, and primarily made of basalt
• Continental crust is thicker, less dense, and made of granite

Earth's Mantle

• The mantle is a thick layer beneath the crust
• It is mostly solid but can flow slowly over time
• Convection currents in the mantle drive plate tectonics
• The mantle is composed of silicate rocks rich in iron and magnesium
• Heat transfer drives plate movement
• The mantle is solid but can flow slowly

Outer Core

• The outer core is a liquid layer of iron and nickel
• Its movement generates Earth's magnetic field, which protects the planet from harmful solar radiation

Inner Core

• The inner core is a solid, dense sphere of iron and nickel
• Extreme pressure keeps the inner core solid, despite high temperatures
• It influences Earth's rotation and magnetic field
• The inner core is made mostly of iron
• Extreme pressure keeps it solid
• The inner core affects Earth's spin

Earth's Composition at a Glance

• Earth's composition varies by layer
• Key elements are iron, oxygen, silicon, and magnesium
• The distribution of elements shapes the Earth's properties
• Crust's major elements - oxygen, silicon, aluminum
• Mantle's major elements - silicon, oxygen, magnesium, and iron
• Outer core's major elements- iron and nickel
• Inner core's major elements - iron and nickel

How We Study Earth's Structure

• Scientists use seismic waves to probe Earth's interior
• Seismic waves are generated by earthquakes and bend/reflect as they travel through different layers
• Analysis of seismic waves reveals layer properties

Conclusion

• Earth's structure is complex and fascinating and plays a vital role
• There are 4 layers: crust, mantle, outer core, inner core
• Approximate Earth radius is 5100 km
• Average density is 5.5 grams per cubic centimeter