Grade 5
Goal 2
Landforms and Weathering
I. Grade Level: 5
II. Unit Title: Landforms and Weathering
III. Unit Length: 9 weeks
IV. Major Unit Goal/Learning Outcomes:
The student will be able to:
o Describe how forces change landforms over time
o Rate the effects of weathering forces
o Understand how water movement shapes landforms
o Explain how different landforms are created
o Describe the characteristics of landforms
o Discuss how water flow effects erosion
o Identify landforms using maps and aerial photographs
o Understand the influence of humans on erosion and deposition
IV. VI. NC English Language Proficiency (ELP) Standard 4 (2008) for Limited English Proficiency Students (LEP) - English Language learners communicate information, ideas, and concepts necessary for academic success in the content area of Science.
V. Objective Chart and RBT Tags
2.01 Identify and analyze forces that cause change in landforms over time including:
Water and Ice;
Wind; and
Gravity.
2.02 Investigate and discuss the role of the water cycle and how movement of water over and through the landscape helps shape land forms.
2.03 Discuss and consider the wearing away and movement of rock and soil in erosion and its importance in forming:
Canyons;
Valleys;
Meanders; and
Tributaries.
2.04 Describe the deposition of eroded material and its importance in establishing landforms including:
Deltas; and
Flood Plains.
2.05 Discuss how the flow of water and the slope of the land affect erosion.
2.06 Identify and use models, maps, and aerial photographs as ways of representing landforms.
2.07 Discuss and analyze how humans influence erosion and deposition in local communities, including school grounds, as a result of:
Clearing land;
Planting vegetation; and
Building dams.
Unit Title: Landforms / Number of Weeks: 9Number / Competency or Objective / RBT Tag
2.01 / Identify and analyze forces that cause change in landforms over time including.
· Water and Ice.
· Wind.
· Gravity. / 4A
2.02 / Investigate and discuss the role of the water cycle and how movement of water over and through the landscape helps shape land forms. / 4B
2.03
2.04
2.05 / Discuss and consider the wearing away and movement of rock and soil in erosion and its importance in forming:
· Canyons.
· Valleys.
· Meanders.
· Tributaries.
Describe the deposition of eroded material and its importance in establishing landforms including:
· Deltas.
· Flood Plains.
Discuss how the flow of water and the slope of the land affect erosion. / 2B
2B
2B
2.06 / Identify and use models, maps, and aerial photographs as ways of representing landforms. / 3C
2.07 / Discuss and analyze how humans influence erosion and deposition in local communities, including school grounds, as a result of:
· Clearing land.
· Planting vegetation.
· Building dams. / 4D
VII. Materials and Equipment
o Rubric for Hands-On Activities (see appendix)
o 3 Baby Food jars
o 3 pieces of chalk small enough to fit in jar, colored chalk optional but preferred
o 1 stopwatch or access to a clock with a second hand
o 1 container of water
o 1 cup of vinegar
o 2-3 teacher selected pictures of water contributing to the shape of the landscape
o 1 plastic container; (the plastic shoeboxes from the dollar store are perfect)
o 1 piece of plastic wrap that covers the top
o Enough tape to go around container
o 1 small bowl
o Soil
o 1 medium bag of ice
o 1 small lamp for heating (a heat lamp will be better)
o Water to fill the small bowl
o Earth material container (tray or tub) for experiments.
o Water source for various flow rates
o Support piece for water source (ruler or similar) needs to fit across tub near end then place water source on edge of tub and support piece. Another suggestion is to use a strong clothespin to attach water source to side of tub.
o Liter Pitcher to transport water from faucet to work area (suggested for teacher’s use)
o Blue food coloring (optional)
o 1 inch high block of wood to increase slope/work with earth (place under one end of container opposite drain for slope manipulation)
o Bucket to capture drainage
o Earth material in 1 gallon size freezer bag (5 parts sand to 1 part powdered clay mixture = approx. 1 liter per bag)
o Duct tape (to cover drain when not in use, and hold ruler in place)
o 1 cup measuring cups
o Newspaper
o Student vehicle for data observations, collection and reflection.
o Safety Equipment
o Book: The Librarian Who Measured the Earth, by Kathryn Lasky
o Internet access: free download of Google Earth
o Map of Mount Mitchell, NC (summit map) from www.topozone.com
o State map or road atlas of North Carolina
o Cardboard
o Scissors
o Markers
o Handout of contour map model
o 4 small clear containers (Solo 9 oz. plastic cups)
o “Face Island” foil model from lesson 2.01
o 1 centimeter grid paper and overhead transparency for each student.
o Overhead marker for each student
o Sand
o Plastic tubs
o Modeling clay
o Centimeter ruler
o Styrofoam plate
o Cooking spray
o Book or object that can elevate plate
o Flax Seed or other small light weight seed
o Erosion photograph (appendix 6)
o Olive Oil
o Small Styrofoam or plastic cup
o Safety goggles or form of protective eye wear
o 4-5 Teacher chosen pictures of famous dams
o 2 plastic containers; (the plastic shoeboxes from the dollar store are perfect) or aluminum baking pan
o 2 clear Styrofoam cups
o Soil or sand
o Ruler
o Water
VIII. Big Ideas:
IX. Unit Notes:
Activity Examples: hands-on, centers, reading maps and building models, small and whole group discussion, using student science notebooks, technology: using computers for research, lecture, student presentations
Flow Chart:
Content Blast
Landforms are the natural features of the earth. Mountains, plateaus, plains and hills are all examples of landforms.
Landforms constantly develop and change as the forces of weathering and erosion change rocks and break them down. Weathering is the force that causes rocks to fragment, crumble, crack and break down either chemically or physically. Erosion carries away the rock debris caused by weathering. The eroded rocks and sediments are deposited by forces such as volcanoes, wind, water, ice, and waves to various depositional environments on the Earth’s surface.
Weathering of Rocks
Rocks weather in different ways and at different rates depending on the mineral composition and location of the rock. The rocks break into small rock fragments as they are weathered. These fragments are broken down further into the particles that comprise soil along with organic material.
When water is frozen it expands, so when water seeps into cracks in rocks then freezes, the expanded ice can cause the rock to split and crack. This process is called ice wedging and it can reduce a rock to rubble over time.
Soil can also collect inside of the cracks of rocks. Plants can grow in this soil and eventually the roots grow large enough to cause pressure on the rocks, causing the crack to expand. The rock can split apart from this expansion.
Minerals found in the rocks can change to other minerals due to the reaction with water or air. Reactions such as rusting or acid formation can also cause the rock to break down into smaller fragments.
Erosion of Rocks
A variety of landforms are carved by water. Moving water erodes rocks and transports the small pieces of rock. Groundwater or underground water can dissolve limestone causing caverns or sinkholes. Ocean waves shape our coastline. The waves can also transport sand and rocks causing extensive erosion.
Wind moving at high speeds can transport a large amount of dust and sand. Erosion of this type shapes deserts by carrying the sand and by sandblasting rock. If soil doesn’t contain plants to hold it in place, it can be exposed to vast amounts of erosion. Loss of soil can cause loss of farmland. During the Dust Bowl in the 1930’s, over cultivation of the farmland removed the native grasses that held the soil in place. Drought and wind then stripped the land of its fertile soil.
Glaciers also help to shape landforms. These huge sheets of ice move slowly over the land in the polar regions of the Earth and in the high mountains where vast amounts of snow build up and turn to ice. The mass of ice moves slowly, only a few inches per day. This movement is caused by layers of ice moving over each other or by the layers of ice sliding on a thin layer of water that begins to melt at the bottom of the glacier. As the glacier moves, it pulls out pieces of the bedrock which become embedded into the bottom of the glacier. As the glacier moves over the land, these pieces of embedded rock grind down on and under the glacier, shaping a variety of landforms. When glaciers retreat, possible landforms that are created include canyons, huge boulders, rock piles, hills, valleys, and lakes.
Forces that Build
Plate tectonics is the major force that builds large masses of land. Faults, volcanoes, and mountains are formed as rocks are moved across the surface of the Earth and shaped mountains. There are smaller building forces that can occur by transporting weathering agents such as water, wind and ice. These are the same forces that erode the land. These weathering agents can carry sediment and deposit it somewhere else through a process called deposition. Deposition of sediment can form beaches, deltas, sand dunes, and change the shape of rivers and coastlines.
People and the Land
People have a direct affect on weathering, erosion, and deposition. People can speed up erosion by clearing the land for farming, housing developments, building roads, deforestation, and strip mining. People change the course of rivers by channeling them and building dams across them. The shapes of mountains are changed by building roads and highways. Coastlines are changing by building roads and houses that may alter the natural changes of the coastline.
Example of Landforms
Valleys are depressions on the surface of the Earth that are bordered by hills or mountains. The naturally formed troughs are made by water and/or ice (glacier) erosion. As rivers and streams flow through valleys, they carry sediments and other materials of land. Fertile soil is found at the bottom or floor of the valley. The valley floor slopes downstream. Valleys formed by rivers have a more v-shape while glaciers form valleys that are characterized by a u-shape.
Plateaus are formed in different ways. Some plateaus are formed as a result of lava flows covering a large area and building up the surface. Plateaus are also formed by the forces of upward folding, followed by the erosion of surrounding land. These forces leave large areas of fairly level highlands that are separated from the surrounding land by steep slopes. Plateaus can be surrounded by mountains or can be higher than the land around them.
Mountains are created by huge forces in the Earth over a long period of time. They are formed by the movements of the Earth’s plates called plate tectonics. The forces of heat and pressure underneath the Earth’s crust cause movements in the Earth’s plates. These movements, plate tectonics, are the geological forces that scientists believe form most of the mountains. The lithosphere of the Earth is divided into sections called plates. Through plate tectonics these plates move and collide, separate, and slide past each other. When some plates collide, one moves under the other and causes the eruption of volcanoes. Other plates compress causing folding and wrinkling of the crust. The Appalachian and the Himalaya Mountain ranges were formed as a result of compression after plates have collided.
Plains are wide stretches of land that do not have significant changes in elevation. Some plains, such as the Great Plains, are found inland while others are found along the coast. Plains contain fertile soil so these areas are often well populated. Roads, towns and cities are also easily built in these areas. Coastal Plains are stretches of lowland along the seacoast that slope towards the ocean. Along the North Carolina coast, the coastal plain is flooded by the ocean and the edge of the North American continent is actually submerged beneath the ocean. In some areas, the plain is part of an elevated ocean floor. Sediments and other solid materials are carried by rivers and waves where they are deposited along the coastline extending the coastline seaward. The sharp upward slope of land along the plain’s inward edge is called the fall line.
Lakes are bodies of water that are different from marine environments. They are small, fairly closed systems, and have less pronounced tides. Thus, the energy levels in lakes are lower than those found in marine environments. When sediment flows into lakes, the coarser sand and gravel are deposited in the shallow areas of the lakes, especially during the summer. The finer silt and clay are deposited in the deeper areas of the lakes, especially during the winter. (Alternating thin layers of light-colored and dark-colored finer grained sediment are called varves, this is one type of lacustrine deposit and forms in all types of lakes, both glacial and nonglacial). While most sediment deposits in lakes come from rivers, some deposits are from wind, ice-rafting and volcanic rock erosion.
Volcanoes create different types of rocks because of the various mineral compositions that compose magma. Depending on the amount of gas found in the magma and the viscosity (thickness) of magma, the volatility of volcanic eruptions and the landforms that are made differ. Magma found in island arcs at the edges of some continents is composed of thin high-silica lava. The magma crystallizes forming rhyolites, andesites, and dacites. Magma from volcanoes that are from continents and oceanic environments are highly fluid and basaltic.
Lava in mountain building (orogenic) environments is the most viscous and has higher gas content. The eruptions from these volcanoes are more explosive and form an extrusive, solid volcanic material called tephra. In the United States most volcanic ash is found in Hawaii, Washington and Oregon. It is also found in Japan, Indonesia, Central America, and other mountainous regions of the world. Rich fertile soil is formed from ash and is used for growing crops.