Lecture 9 unit 3 Interior of the Earth.pptx

Interior of the Earth

1. Interior of the Earth Class: ADP II Semester QAU Islamabad Syed Abbas Hyder Shah Lecturer in Geography IMCG, Humak, Model Town Islamabad

2. Interior of the Earth Understanding Earth's Internal Layers and Structure

3. Introduction to Earth's Interior Most knowledge comes from studying seismic waves. Layers: Crust, Mantle, Outer Core, Inner Core.

4. The Earth's Crust Outermost layer (5–70 km thick). Oceanic crust: Dense, basaltic; Continental crust: Less dense, granitic.

5. Properties of the Earth's Crust Composition: Silicates of aluminum (sial) and magnesium (sima). Varies in thickness and density.

6. The Mantle Largest layer (84% of Earth's volume). Upper & Lower Mantle; semi-solid, responsible for convection currents.

7. The Outer Core Liquid layer composed of iron and nickel. Responsible for Earth's magnetic field (geodynamo effect).

8. The Inner Core Solid due to immense pressure, composed mainly of iron and nickel. Temperatures up to 6,000°C.

9. Major Discontinuities Inside Earth Mohorovičić Discontinuity (Moho): Between crust and mantle. Gutenberg Discontinuity: Between mantle and outer core. Lehmann Discontinuity: Between outer and inner core.

10. How We Study Earth's Interior Seismic wave analysis from earthquakes. Density and temperature variations with depth.

11. Summary & Conclusion Earth's interior plays a crucial role in geology and geophysics. Understanding layers helps predict earthquakes and volcanic activity.