Part Three: Weathering and Erosion Department of Mathematics and Science

What role does flowing water have in all of the different sizes of rocks in streams? Hypothesis: __________________________ Engage: Direct students to look at the stream pictures and ask the essential question on the slide. Department of Mathematics and Science

Weathering… Some changes happen so slowly that you would never see them. It took about 6 million years for the Colorado River to carve the Grand Canyon.

What are factors that affect the surface? Earth’s surface is exposed to: Water Wind Ice Growing plants Each of these can break down rocks.

PhysicalWeathering http://geomaps.wr.usgs.gov/parks/project/index.html 1. 3. 2. Explore and Explain: Read in SF gr. 4 chapter 9 lessons 1 &2. Review weathering by watching the hyperlinked video and/or ScienceSaurus Handbook: Earth’s Changing Surface pp. 170-173 Evaluate: Have students number a paper in their notebook and identify the 4 types of weathering shown in the pictures. Wind rain Ice Plant roots 4. Department of Mathematics and Science

Water Some of the minerals in rocks dissolve in water. Underground huge caverns can form Moving water also carries rough pieces of sand that can chip away rocks. http://www.passmyexams.co.uk/GCSE/physics/what-is-weathering.html

Ice wedging causes many rocks to break.

Growing Plants… Plant roots can grow in cracks. The pressure of a confined growing root can be substantial. These pressures make cracks in the rocks larger, and, as roots grow, they can break rocks apart.

Erosion Erosion carries weathered materials aways from a place. It is the movement of sediments from one place to another. Water is the primary agent of erosion, though wind and glacier ice also contribute . Explore and Explain: Review weathering and erosion by playing the hyperlink Erosion. Have students define and give examples of erosion in their notebook. Evaluation: Ask: What part do weathering and erosion play in the formation of sedimentary rocks? Weathering and erosion create the small rock particles that, along with organic matter, make up soils. The same small rock particles can be transported by water and find their way to the bottom of lakes and oceans where they form layers. As more and more layers are deposited, the pressure from the weight above and consolidation of the minerals and the particles may cause them to cement together, creating a sedimentary rock. Read more: http://wiki.answers.com/Q/How_do_the_processes_of_weathering_and_erosion_relate_to_the_formation_of_soils_and_sedimentary_rocks#ixzz1ldn6keFt

Moving Water… Rain, streams, and rivers cause erosion. As water moves across the land, it carries away soil, sand, and small rocks. When the water slows down, the materials fall out and are deposited.

Wind… Wind erosion happens because of the damage of land as a result of wind removing soil from an area. Most often, wind erosion occurs on flat land in dry or sandy areas. Wind can move and deposit particles of rock, soil, and sand. Wind makes the most changes when it blows over open areas such as deserts, plowed fields, and beaches. The amount of erosion caused by wind depends on the speed of the wind and how long it blows. The higher the wind’s speed and the longer the wind blows, the greater the erosion. Wind builds land when it deposits materials.

Moving Ice In mountains and in cold parts, glaciers form. Glaciers that form in mountain valleys move downward very slowly. As they move, they scrape away pebbles, rocks, and even huge boulders. These materials cut away more land as the glacier drags them along. If a glacier melts and shrinks, the materials are deposited.

Florida Erosion… Severe coastal erosion can occur over a very short period of time when the state is impacted by hurricanes, tropical storms and other weather systems. Heavy winds and water surges can affect the shorelines. https://www.history .com/topics/dust-bowl

https://www.youtube.com/watch?v=srbAqqi3HBo https://www.youtube.com/watch?v=7vAFeFsk0Vk Landslide

FCAT 2.0 Question The agents of erosion include all except _____________. rock and rock fragments under the influence of gravity B) currents such as wind, water, or ice flow C) the breaking down of rock through processes where no movement is involved D) poor land uses such as deforestation and unmanaged construction Explain/Evaluate Department of Mathematics and Science

FCAT 2.0 Question 2. What occurs when gravity pulls loose material down to the bottom of a slope in a sudden motion? A) tsunami B) flood C) landslide D) earthquake Explain/Evaluate Department of Mathematics and Science

FCAT 2.0 Question 3. Weathering can be caused by ___________________. A) canyons, caves, and landslides B) rain, wind, and plant roots C) rivers, mountains, and currents D) tides, mice, and glaciers Explain/Evaluate Department of Mathematics and Science

FCAT 2.0 Question 4. How did weathering and erosion form the Grand Canyon? Flooding caused landslides many years ago, and the canyon was formed very quickly. B) A great earthquake caused the a giant crack in the earth, and the canyon was formed. C) Many volcanoes in that area erupted, and the lava caused the rocks to melt away. D) Rain, wind, and the river cut into the rock and soil, removed it, and slowly formed the canyon. Explain/Evaluate Department of Mathematics and Science