Year 8 Science: Earth and Space Unit

Earth and Space

• This is a Year 8 science unit on Earth and Space.

Planet Earth - The Blue Planet

• No specific information provided.

Geology

• Geology is the study of Earth.
• It's the primary earth science, looking at how the Earth is formed, its structure and composition, and the processes acting on it.

The Earth's Structure

• What is Earth made of?
• What evidence supports your hypothesis about Earth's structure?

Earth's Interior

• Earth has layers:
  • Crust: Rocky, outer layer.
  • Mantle: Semi-liquid, high temperature layer below crust. Cooler sections next to the crust are less mobile than hotter sections close to the core.
  • Core: Center layer divided into two sections:
    • Outer core: Liquid.
    • Inner core: Solid.

The Earth's Layers

• Crust: Rocky, outer layer beneath the feet.
• Mantle: Semi-liquid, high-temperature layer below the crust. Cooler sections near to the crust are less mobile than the hotter section next to the core.
• Core: Layer at the center. Divided in two sections:
  • Outer core: Liquid.
  • Inner core: Solid.

Anatomy of the Earth

• Link to a YouTube video.

The Crust

• Continental Crust:
  • Thick (10-70km).
  • Less dense than oceanic crust.
  • Mostly continental crust.
• Oceanic Crust:
  • Thin (~7km).
  • Denser than continental crust.
• Crust is made of these two types of crust.

Lithosphere and Asthenosphere

• The crust and top of the mantle are called the lithosphere.
• It's a rigid layer, mostly made of rocks.
• Below the lithosphere is the asthenosphere.
• This is hot, semi-solid material.
• The lithosphere 'floats' on top of the asthenosphere.

Activity - Earth's Layers

• Draw a detailed labeled diagram of Earth's cross-section, showing its major layers: Crust, Mantle, Outer Core, Inner Core, Lithosphere, and Asthenosphere.
• Show the layering and how the layers are related to each other in terms of depth.

Reflection

• Compare the thickness of the crust to the other layers of the Earth.
• Explain the advantage of using a scale model to represent Earth's layers compared to using the analogy of a nectarine.

Continental Drift

• Continents can fit together like pieces of a puzzle.
• Evidence suggests continents were once connected.

Alfred Wegener's Evidence

• Fossil evidence shows that the continents were once joined.
• Fossil remains of plants, reptiles, and animals found on different continents suggest that once they were all together.

The Tectonic Plate Theory

• Scientists combined ideas from previous discoveries and formed a clear theory to explain how Earth's tectonic plates move.
• New technological developments like sonar and satellite measurement contributed to this understanding.
• Plates move over the mantle.

Plate Tectonics and Continents

• Tectonic plates are massive pieces of the lithosphere.
• They include both oceanic and continental crust.
• The continents move with the plates that they are part of.
• Plate movement reshapes the Earth's surface.

Plate Tectonics and Egg Shells

• Earth's plates are like a cracked egg shell.
• Plates are categorized as major, minor, and micro.

Plate Tectonics

• Diagrams show different tectonic plates, and their locations on Earth.

Moving and Changing Tectonic Plates

• Diagrams show the movement of tectonic plates at different time periods.

How do Tectonic Plates Move

• This shows how mantle convection drives tectonic plate movement.

Factors Affecting Earth's Surface Shaping

• The movement of tectonic plates affects the Earth's surface.
• This includes mountain building, volcanic activity, and earthquakes.

Plate Movement

• Diagrams illustrate the movement of various tectonic plates (North American, Eurasian, Pacific, African, etc.).

Plate Boundaries

• The border between two plates is a plate boundary.
• There are three types:
  • Divergent (plates move apart).
  • Convergent (plates move together).
  • Transform (plates slide past each other).
• These plate boundaries create landforms like mountains, volcanoes, ridges, and valleys.

Three types of plate boundary

• Divergent, Convergent, Transform