4 th Grade Earth Science

1. 4thGrade Earth Science Chapter 9 Changing of Earth’s Surface

2. What is the Earth made of? • Landforms on Earth include: • __________ • __________ - flat land • ________ - a deep crack • ______ - flatlands with few trees • _______ - on land where mountains are close together • ______ - beneath the ocean, long row of towering mountains • ________ - long narrow canyons in the ocean floor Mountains Plateaus Gorges Plains valleys Ridges Trenches

3. Earth’s Features • Earth’s surface is made up of many different __________. • Earth’s surface is constantly ________ and so are the landforms • ___________ - the process of breaking down rock into smaller pieces • Forces of __________ include ________ and _____ Landforms changing weathering weathering water ice

4. Mechanical / Chemical Weathering • _________________ - process of breaking down rock into smaller pieces as a result of ice or water – MINERALS THAT MAKE UP THE ROCK DO NOT CHANGE! • ________________ - minerals that make up the rock change. • The cause of chemical weathering is a _________ with something in the environment such as ____ or ________ Mechanical Weathering Chemical Weathering reaction water oxygen

5. Erosion • ________ - the process by which soil and sediments are transferred from one location to another • The movement of soil and sediments can be caused by: • _________ • ________ • ______ • ________ erosion wind water ice gravity

6. Water • _________ - solid particles that are moved from one place to another __________ - sediments that form during weathering and erosion are deposited in another location During the process of deposition, the _______ and ________ of a river’s flow changes As rivers flow to the oceans they carry ________ and ______________ which are useful to plants and animals to carry out their __________ sediments deposition shape direction sediments Dissolved minerals Life processes

7. Soil Erosion • Areas of land with no plant covering are susceptible to __________ • __________ - help prevent soil erosion by holding the soil in place • ___________ - planted by farmers in between harvests to prevent soil erosion and add nutrients to the soil • ______________ - years of drought and poor farming practices left bare areas of soil Soil erosion Plant roots Cover crops Dust Bowl of 1930’s

8. Soil • ____ - made of weathered rock, air, water, and the remains of living things. • __________ - process of breaking down rocks through physical factors such as _____, _________, _______ or__________________. • ________ = non-living parts of the soil • As rock breaks down small pieces collect on the surface soil weathering frost drought rainwater Changes in temperature inorganic

9. Volcanoes • __________ occur when magma from the mantle either flows or explodes through the crust. • Opening in the surface of the Earth through which magma rises • Occur near ______________ • Theory of plate tectonics – one plate sinks beneath another at a plate boundary – sinking crust melts into _______. • _____ - Magma that reaches the surface Volcanoes Plate boundaries magma lava

10. Draw and Label Volcanoe page 270-271

11. Earthquakes • _________ are caused by the sudden shifting of rock as tectonic plates shift positions • Pressure builds up, rocks lurch forward, and the Earth’s crust shakes. • ______ - the underground point where the earthquake occurs • ________ - point on the Earth’s surface directly above the focus. Earthquakes focus epicenter

12. Waves • Energy from the earthquake is carried by _______. • Waves spread out from the _____ and ________. • Waves can cause the Earth to move ________, ___________, or in a ___________ • As the waves spread out from the epicenter, they __________. waves focus Volcanoes Up and down Back and forth Circular motion Lose energy

13. Earthquakes and Plate boundaries • ____________ and _________ have had the most earthquakes because they are located on a ____________ between the Pacific plate and the North American Plate. • The strength of an earthquake can be measured on a ____________ - a series of numbers that is based on the amount of energy that is released. California Alaska Plate Boundary Magnitude scale