Chapter 9 Science Notes Lessons 1, 2, and 3

Chapter 9 Vocabulary landform-a natural feature on Earth’s surface; landforms include mountains, hills, valleys, plains, plateaus, and coastal features weathering-a gradual wearing away or changing of rock and soil caused by water, ice, temperature changes, wind, chemicals, or living things erosion-the moving of pieces of soil or rock by mechanisms including gravity, wind, water, ice, or plants or animals

Chapter 9 Vocabulary deposition-the laying down of rock, soil, organic matter, or other material on the surface of Earth landslide-a rapid downhill movement of large amounts of rock and soil volcano-a cone-shaped landform that sometimes releases hot rocks, gases, and ashes fault-a break or crack in Earth where the rocks on one side have moved relative to the rocks on the other side

Chapter 9 Vocabulary earthquake-a shaking of Earth’s crust or lithosphere caused by sudden shifting movements in the crust epicenter-the point on Earth’s surface directly above the focus of an earthquake

Lesson 1 The outer surface of Earth is called the crust. Types of landforms include: mountains, plains, plateaus, peninsulas, valleys, and canyons Water, ice, temperature changes, and living things can cause weathering.

Lesson 1 continued Ice can cause physical weathering. Water from rain or snow can get into the cracks of rocks. If it freezes, it forms ice. The ice forces the sides of the crack out. The crack gets larger and the rock splits. There are two types of weathering: Physical Weathering : Size of rock changes Chemical Weathering: Chemicals cause rocks to change into different materials

Lesson 2 Sometimes deposition happens slowly, other times it happens fast. Avalanches and landslides pick up rock and soil causing erosion as they move downhill. Landslides and avalanches are caused by gravity.

Lesson 2 Continued Ways to control erosion and deposition include the following: Growing plants on hills Plowing hilly fields in steps, called terraces Building barriers along the seashore

Lesson 3 Magma is very hot rock that is partially melted into a liquid underground. Vents are openings in volcanoes that allow hot rock, gas, and ash to burst out. An active volcano has frequent eruptions or shows signs of future eruptions

Lesson 3 Continued A volcano that has not erupted for a long time is called a dormant volcano. A volcano is called extinct if scientists think it will never erupt again. Plate movement along a fault causes most earthquakes. The focus is the place underground where the plates start to move and the earthquake begins.