Planet Earth

Section 1.1 Model of Earth Model Geologists Definition: an idea of something that can’t be fully known or seen. A way to picture an object in its real form. Example: Globe is a model of Earth Geologists Definition: scientists that study Earth, who use models to understand the inner structure.

Three Major Layers of the Earth Starting from the inner most layer to the outer most layer. Inner Core: consists mainly of solid iron and nickel, reaching temperatures of 7000 degrees Celsius Outer Core: thought to be liquid due to pressure not being great enough to turn molten rock into solid Crust: covers the surface of Earth.

The Earth’s Crust Crust: All living things are found here Storehouse of minerals (ex. iron, copper ore) Fossil fuels (ex. Oil, natural gas, coal) **supply energy needs Note: What makes up the crust - - covered with vegetation, fresh and saltwater areas, BUT these only form a thick layer most of the crust is made up of solid rock

Section 1.2 - Sudden Earth Events What are some Examples???? Earthquake Volcanic Eruption Typhoon Tsunami Tornado etc

Earthquakes – What are they and what causes them? Definition: tremblings/ vibrations in the ground Cause Sudden release of energy that has slowly been building up within the Earth’s Crust. ** Pressure built up causes the rock to first change in shape and then break This is called “The First Break” or is known as the “FOCUS”

These waves are called “SEISMIC WAVES”- shaking that you will feel comes from the seismic waves moving through the ground. Epicentre: point on the surface directly above the focus

Measuring Strength of Earthquakes Various scales to determine the strength /magnitude of an earthquake Usually given a number on a “Richter Scale” Charles Richter – American developed in 1935, starts at 0 for every one increase means it is 10 times amount of ground motion

Volcanoes Activity (pg. 360) Define the term VOLCANO Draw, Color and Label (in your own words) the 7 steps in Figure 1.10

Section 1.3 Incremental Changes: Wind, Water and Ice Jigsaw Puzzle Activity -- Get into groups of 4 -- Number each person 1, 2, 3, and 4 1s: will become experts about Weathering 2s: will become experts about Erosion 3s: will become experts about Deposition 4s: will become experts about Glaciers -- please get into expert groups -- fill in your booklets about your area of expertise (15 minutes) -- you will then come and enter the info on the smart board

Weathering Mechanical Weathering This occurs when rock is broken apart by physical forces such as water and wind. - mechanical weathering ‘wears away’ - sedimentation ‘builds-up’ Chemical Weathering - This occurs when water and oxygen react with the minerals in rocks to produce new minerals. Biological Weathering - living things (plants, animals, bacteria and fungi ) can breakdown rock - plant roots force their way into small spaces in rocks and soil. As the roots grow they apply enormous amounts of pressure on their surroundings, breaking apart rocks.

Erosion & The Effects of Moving Water Water is one of the most powerful causes of erosion. Sudden or incremental changes occur due to the flowing of water - rivers, rain, ocean waves. As rivers flow they carry a load of silt, sand, mud and gravel called sediment. When a river becomes mature it begins to meander (curving its bed from side to side). As it slows the sediment begins to fall to the bottom. Sedimentation is the process of sediment being deposited, usually at the bottom of oceans, lakes and rivers. Landforms created by flowing water are called Fluvial landforms. The powerful forces of erosion caused by moving water wear away rock and soil and transport them to other locations.

Eroding Away Agents of erosion include: glaciers, gravity, wind, and water. Changes can occur gradually (glaciers) or rapidly (flash floods, landslides, rock slides). Erosion causes landslides and rock slides wind carries rock particles across the landscape, eroding the land by wearing away soil. (planting vegetation, contour farming and reduced tillage can reduce the effects of wind erosion).

Glaciers Large rocks caught up in a glacier and then left behind when the glacier recedes are called drumlins and moraines. Scratching and grinding, made in the bedrock, by glaciers carrying rocks is called erosion. As the glacier melts (or, retreats) it leaves behind sediment in the form of small hills, called drumlins and snake-like hills called eskers. Glacier: a moving mass of ice and snow. Bedrock: the layer of solid rock beneath the loose rock fragments.