Planet Earth: What is it made of and how does it change? Planet Earth Unit Topic 1 (Pgs. 352-366) Planet Earth: What is it made of and how does it change?

How were these Alberta landforms created?

What do YOU think is in our planet? Geologists are scientists that study the Earth

The Layers of Planet Earth

The Layers of Planet Earth The Crust The outer layer of Earth, made up of the features we see (mountains, valleys, hills, plains, etc.) This layer is bout 10-90 km thick (the thinnest of all the layers) The Mantle The upper mantle is solid like the crust The lower mantle melted rock that flows slowly (very hot here) This layer is 2900 km thick and makes up 67% of the Earth’s mass The crust and the upper mantle (solid layers) form the lithosphere

The Layers of Planet Earth The Outer Core This layer is so hot that rock is completely liquefied (molten) This layer is about 2200 km thick The Inner Core This layer is solid even though it is VERY hot (7000°C) The massive pressure from the other layers press the inner core into a hard ball of metals This layer is about 1250 km thick

The Earth changes all the time, sometimes very quickly and sometimes very slowly Sudden Changes Earthquakes Volcanoes Tsunamis Hurricanes Tornados Long-Term Changes Erosion Wind Water Ice Weathering

Earthquakes What is an earthquake? How does an earthquake happen? What are some of the side effects of an earthquake?

How Earthquakes Work The first place where the rocks below the surface break is called the focus, and occurs along fault lines The energy released by this sudden break is called spreads as waves called seismic waves The point on the surface of the Earth directly above the focus is called the epicentre Geologists use a seismogram to locate the epicentre and provide aid to those injured

No. of earthquakes per year The Richter Scale Richter scale no. No. of earthquakes per year Typical effects of this magnitude < 3.4 800 000 Detected only by seismometers 3.5 - 4.2 30 000 Just about noticeable indoors 4.3 - 4.8 4 800 Most people notice them, windows rattle. 4.9 - 5.4 1400 Everyone notices them, dishes may break, open doors swing. 5.5 - 6.1 500 Slight damage to buildings, plaster cracks, bricks fall. 6.2 6.9 100 Much damage to buildings: chimneys fall, houses move on foundations. 7.0 - 7.3 15 Serious damage: bridges twist, walls fracture, buildings may collapse. 7.4 - 7.9 4 Great damage, most buildings collapse. > 8.0 One every 5 to 10 years Total damage, surface waves seen, objects thrown in the air.

Volcanoes A volcano is an opening in the Earth’s crust that allows solid and molten rock to escape Volcanoes are easier to predict than earthquakes Magma - molten rock within the Earth Lava - molten rock that flows out of a volcano Ash - small, burnt particles from a volcanic eruption

Gradual Changes to the Earth Weathering The process of breaking down rocks by water, wind, or ice Erosion occurs when the pieces of rock broken down from weathering move from place to place

3 Types of Weathering Mechanical Chemical Biological Rocks are broken apart by forces, like wind or water Chemical Rocks are broken apart by chemicals, like acid rain or air pollution Biological Rocks are broken apart by living things, like tree roots or animal/human use

The Power of Moving Water As rivers flow they carry sand, gravel, mud  these are called sediments As these sediments sit on the bottom of lakes, rivers, oceans they become hard rocks  this is called sedimentation

Fast vs. Slow Glaciers slowly grow and shrink, scraping the Earth’s crust as they move Landslide