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Earth’s Surface: Unit 1 The Big Idea:

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Presentation on theme: "Earth’s Surface: Unit 1 The Big Idea:"— Presentation transcript:

1 Earth’s Surface: Unit 1 The Big Idea:
Continuous processes on Earth’s surface result in the formation and destruction of landforms and the formation of soil. Earth’s Surface: Unit 1

2 Unit 1 Lesson 1 Earth’s Spheres
What on Earth? Earth systems- all of the matter, energy, and processes within Earth’s boundary. A system is a group of related objects or parts that work together to form a whole. The Earth system is all of the matter, energy, and processes within Earth’s boundary. Earth is a complex system made of living and nonliving things, and matter and energy continuously cycle through the smaller systems.

3 Unit 1 Lesson 1 Earth’s Spheres
Geosphere Geosphere- mostly solid, rock part of Earth. It extends from the center to the surface of Earth. Layers of Geosphere Crust Mantle Core Lithosphere is the rigid outer layer of Earth. Lithosphere is apart of the geosphere. It includes the crust and upper mantle, about 100km thick. The lithosphere is divided into tectonic plates. When these plates interact w/ one another, many different geologic events are possible, i.e. volcanic eruptions, earthquakes, & forming mtns. The thin, outermost layer of the geosphere is called the crust. It is made mostly of silicate minerals. Oceanic crust is 5 to 10 km thick. Continental crust is 35 to 70 km thick. The mantle is the layer that lies below the crust. It is about 2,900 km thick. The mantle is made of very slow-flowing, solid rock, consisting of silicate minerals that are denser than the silicates in the crust. Earth’s central part, called the core, has a radius of about 3,500 km. It is made of iron and nickel and is very dense.

4 Layers of the Geosphere
Crust km (ocean) km (continental), made of silicates, LEAST DENSE Mantle-about 2900 km thick, very slow flowing, solid rock, made of silicate minerals that are denser than the crust. Core- Outer : liquid layer km thick Inner: solid, dense core made of Fe & Ni MOST DENSE

5 Unit 1 Lesson 1 Earth’s Spheres
Got Water? Hydrosphere- liquid water including oceans, lakes, rivers, marshes, streams, swamps, ground water, rain & water droplets in clouds. 97% of all water on Earth is the saltwater found in oceans. Oceans cover 71% of Earth. Water is constantly moving, thru ocean currents due to wind and differences in density. From Earth’s surface to air via evaporation & back again as rain. It flows in rivers & through rock underground and even in & out of living things.

6 Unit 1 Lesson 1 Earth’s Spheres
Ice, Ice Baby Cryosphere- made up of all the frozen water on Earth. All the ice, sea ice, glaciers, ice shelves, icebergs, & permafrost. Most of the frozen water is found in ice caps in Antarctica & Artic. However, glaciers are found in mountains & at high latitudes all over the world. Of course the amount changes with seasons which in turn play an important role in climate & survival of many species.

7 What a Gas! Atmosphere- made of invisible gases that surround Earth.
Unit 1 Lesson 1 Earth’s Spheres What a Gas! Atmosphere- made of invisible gases that surround Earth. The atmosphere is about 78% Nitrogen 21% Oxygen 1% many other gases (Ar, CO2, & water vapor). It extends outward about 500 to 600 km from Earth’s surface, but most of the gases lie within 8 to 50 km of Earth’s surface. The atmosphere is about 78 percent nitrogen, 21 percent oxygen, and 1 percent many other gases. Minor gases in the atmosphere include argon, carbon dioxide, and water vapor. The atmosphere contains the air we breathe. It also traps some energy from the sun, which helps keep Earth warm enough for living things to survive and multiply. Some gases of the atmosphere absorb and reflect harmful ultraviolet (UV) rays from the sun, protecting Earth and its living things. The atmosphere also causes space debris to burn up before reaching Earth’s surface and causing harm.

8 Unit 1 Lesson 1 Earth’s Spheres
Living Together Biosphere- made up of living things and the areas of Earth where they are found. Organisms usually need oxygen or carbon dioxide to carry out life processes. Liquid water, moderate temperatures, and a stable source of energy are also important for most living things.

9 Unit 1 Lesson 1 Earth’s Spheres
What’s the Matter? All of the five spheres of Earth interact as matter & energy change & cycle through the system. (Think of the water, nitrogen & carbon cycles) Energy Budget- formed with movement of energy through Earth’s system. A result of these interactions is that they make life on Earth possible. Earth’s spheres interact as matter moves between them. In some processes, matter moves through several spheres. Earth’s spheres also interact as energy moves from one sphere to another, and back and forth between spheres. Balancing the Budget Almost all of Earth’s energy comes from the sun. A tiny fraction of Earth’s energy comes from ocean tides and geothermal sources such as lava and magma. Energy is transferred between Earth’s spheres, but it is not created or destroyed. Any addition of energy to one sphere must be balanced by an equal subtraction of energy from another sphere. When Earth’s energy flow is balanced, global temperatures stay relatively stable over long periods of time. Sometimes, changes in the system cause Earth’s energy budget to become unbalanced. What can disturb Earth’s energy budget? An increase in greenhouse gases traps more energy in the atmosphere and decreases the amount of energy radiated out to space. Polar ice and glaciers reflect sunlight. When the ice melts, the exposed water and land absorb and then radiate more energy than the ice did. In each case, Earth’s atmosphere becomes warmer, which may lead to climate changes Trace the flow of energy through Earth’s system.

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11 Unit 1 Lesson 2 Weathering
Break It Down Weathering- breakdown of rock material by physical and chemical processes. Types of Weathering 1. Physical 2. Chemical

12 Unit 1 Lesson 2 Weathering
Physical weathering process by which rock is broken down into smaller pieces by physical changes, but does NOT change composition. Ice wedging (frost wedging)- crack growth Exfoliation Animals-mix soil, air & drainage Plants-reason crack growth Abrasion Wind The composition of the material does not change during physical weathering. Agents of physical weathering include temperature changes, pressure changes, plant and animal actions, water, wind, and gravity. Changes in temperature can cause a rock to break apart by weakening the structure of the rock. Heat causes the rock to expand; cold causes it to contract. Ice wedging, or frost wedging, causes cracks in rocks to widen with repeated cycles of freezing and thawing. Rocks that formed under pressure deep within Earth can be exposed to the surface. As material is removed above the rock, the pressure decreases and the rock expands. Exfoliation is the process by which the outer layers of rock slowly peel away due to pressure changes. Animals can cause physical weathering by digging burrows. ON THE TEST: Animals can loosen and mix the soil, increasing air in the soil and the ability to drain water New rocks, soils, and other materials become exposed at the surface as a result of animal actions. Materials exposed at the surface are more likely to undergo weathering than those below. Roots of plants start out as tiny strands that may grow in small cracks in rocks. As the roots grow, they put more pressure on the rock, causing the rock to expand and eventually break apart.

13 Unit 1 Lesson 2 Weathering
Physical Weathering Water Abrasion -breaking down & wearing away of rock material by the mechanical action of other rocks. Wind Gravity Three agents of physical weathering that can cause abrasion are moving water, wind, and gravity. Rocks suspended in a glacier can also cause abrasion of other rocks on Earth’s surface. ON THE TEST: Change in size

14 Unit 1 Lesson 2 Weathering
Chemical Weathering breakdown of rocks by chemical reactions which changes composition & appearance. Oxidation-chemicals in rock combine with oxygen in the air or in water, sometimes indicated by color change. Acid precipitation -occurs when strong acids fall to Earth as rain, sleet, or snow. Chemical weathering changes both the composition and appearance of rocks. ON THE TEST: THEY CRUMBLE MORE EASY Agents of chemical weathering include oxygen in the air and acids. Acids can cause chemical weathering by breaking down minerals faster than water alone. Acids in the atmosphere are created when chemicals combine with water in the air. Acids in groundwater can cause rock to dissolve. A small crack in the rock can result in the formation of extensive cave systems carved out over time. Rock material dissolved in groundwater can be carried and deposited in new locations over time. Acids produced by living things can cause chemical weathering. Chemical reactions occur as these acids move through tiny spaces in rock material. As the acids seep deeper, cracks form. Eventually, the rock can break apart. ON THE TEST: Things that decay can add acids to the soil causing chemical weathering.

15 Unit 1 Lesson 3 Erosion & Deposition
Go with the Flow Erosion process by which sediment & other materials are moved from one place to another. Deposition process by which eroded material is dropped. Rivers and streams erode soil, rock, and sediment. Sediment is tiny grains of broken-down rock. Erosion causes changes to Earth’s surface. Materials in rivers and streams are eventually dropped, or deposited, downstream. Deposition occurs when gravity’s downward pull on sediment is greater than the push of flowing water or wind. On the test: Things that cause MORE erosion Slope –increases speed and amount of erosion Rain (mudslides)

16 Run of a River Floodplain Oxbow Meander Delta Alluvial fan Groundwater
Unit 1 Lesson 3 Erosion & Deposition Run of a River Floodplain Oxbow Meander Delta Alluvial fan Groundwater Shoreline Beach A floodplain is a flat area formed from many layers of deposited sediment. Sediment often contains nutrients for plant growth. As a result, floodplains are often very fertile. Curves and bends in a stream channel are called meanders. Moving water erodes the outside banks and deposits sediment along the inside banks. During a flood, a meander can be cut off, forming a crescent-shaped lake called an oxbow lake. A delta is a fan-shaped pattern of deposited sediment load. An alluvial fan is a fan-shaped deposit that forms on dry land. Groundwater is the water located within the rocks below Earth’s surface. Acidic groundwater can dissolve rock, forming underground caves. Water dripping from cracks in a cave’s ceiling leaves behind icicle-shaped deposits called stalactites and stalagmites. If the roof of a cave collapses, it may leave a circular depression called a sinkhole. A shoreline is the place where land and a body of water meet. Ocean waves and currents, or streamlike movements of water, can erode and deposit materials. A beach is an area of shoreline that is made up of material deposited by waves and currents. The size and shape of materials on a beach depend on how far the material has traveled, the type of material, and how it is eroded. A sandbar is an underwater or exposed ridge of sand, gravel, or shell material. A barrier island is a long, narrow island, usually made of sand, that forms parallel to the shoreline a short distance offshore.

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18 Unit 1 Lesson 4 BY Wind, Ice, & Gravity
Shaping the Earth Groundwater -water located within the rocks below Earth’s surface. Acidic groundwater can dissolve rock, forming underground caves. Wind (sand dunes/loess) heaviest settle first Glacial drift -general term for all materials carried & deposited by a glacier. Gravity- influences the movement of water and ice. Gravity also moves rocks and soil downslope. ON THE TEST: Alpine glaciers cause U shaped valleys and rugged landscape, continental glaciers form flat landscapes. ON THE TEST: Glaciers are found on all parts of the earth that are cold and more snow falls than melts. ON THE TEST: When glaciers are melting they lose the heaviest materials first. ON THE TEST: Dunes are mounds of wind-deposited sand, common in deserts and along the shores of lakes and oceans. Caused by wind. Loess consists of thick deposits of windblown, fine-grained sediment. RICH IN MINERALS Loess deposits can be found far from their original source and can build up over thousands or millions of years. Loess forms good soils for growing crops. Rapid mass movements usually happen on steep slopes and are the most destructive. A rockfall happens when loose rocks fall down a steep slope. A landslide is the sudden and rapid movement of a large amount of material downslope. During the last Ice Age, an ice dam held back the water of Glacial Lake Missoula. The dam broke and emptied the entire lake within 48 hours, forming huge waterfalls, deep canyons, and tall ripple marks in the land. Lake Missoula reformed and flooded about 40 more times. Gravity influences the movement of water and ice. Gravity also moves rocks and soil downslope. Mass movement is this shifting of materials due to gravity. Creep is the extremely slow movement of material downslope. A mudflow is a rapid movement of a large mass of mud. Mudflows happen when a large amount of water mixes with soil and rock. Deforestation, volcanic eruptions, and heavy rains can all create mudflows.

19 Unit 1 Lesson 5 Soil Formation
The Dirt on Soil Soil - loose mixture of rock fragments, organic matter, water, and air that can support the growth of vegetation. Soil profile - vertical section of soil that shows all the different layers. Soil horizon - Each layer in the soil profile that has different physical properties. The first step in soil formation is the weathering of parent rock into smaller pieces. Eventually, very small particles from parent rock are mixed in with organic matter to form soil. Rock is broken down by weathering and plant root growth to form sediment. The type of sediment in soil depends on what rocks are in the area. This helps to explain why soils differ from place to place. Some microorganisms, such as bacteria and fungi, decompose the remains of plants and animals. These remains are decayed organic matter called humus. It contains nutrients that plants need to grow. Larger animals, such as earthworms and moles, loosen and mix the soil as they burrow, increasing the air in the soil and its ability to drain water. ON THE TEST: PUT ON FRONT BOARD

20 Unit 1 Lesson 5 Soil Formation
Soil Horizons A horizon - topmost layer of soil, often referred to as topsoil. It contains the most humus. B horizon -has less humus. Water carries material from the A to the B horizon, in a process called leaching. C horizon -lies below the B horizon and directly above the parent rock. It contains the largest rock fragments and usually no organic matter. The main horizons include the A horizon, B horizon, and C horizon.

21 Thick Tops, Rocky Bottoms
Unit 1 Lesson 5 Soil Formation Thick Tops, Rocky Bottoms What factors determine how long it takes for soils to form? Parent rock type- determines soil type Climate Topography Plants and animals-add organic material by breaking down remains ON THE TEST: Rock type: The rate of weathering depends on the structure of the rock and minerals that make up the rock. The parent rock type will determine what type of soil will be made. Climate: Soil usually develops more quickly in warm, wet areas than in cold, dry areas. Topography: Soils usually develop faster in flatter areas where sediments are not easily eroded. Plants and animals: Without a lot of plants and animals, soil tends to develop slowly. ON THE TEST: How do microorganisms influences chemical characteristics- they add organic material to the soil by breaking down the remains of plants and animals Primary factors that affect soil formation: Parent rock type Climate Plants and animals Time Topography

22 What are some properties of soil?
Unit 1 Lesson 5 Soil Formation What are some properties of soil? How does the pore space of the soil on the left compare to that of the soil on the right? Soil fertility describes how well a soil can support plant growth. Soil fertility depends on the climate and topography of the area, and the amount of humus, minerals, and nutrients in the soil. Soil properties are used to classify different soils. These properties include soil texture, color, chemistry, pore space, and fertility. Soil texture describes the relative amounts of differently sized soil particles. Soil particles are classified as sand (largest particles), silt, or clay (smallest particles). Soil color depends on the minerals and organic matter that make up the soil. Soil pH is a measure of how acidic or basic the soil is. Soil pH depends on the minerals, sediment, and organic matter found in the soil. Pore space describes the spaces between soil particles. Water and air are found in the pore spaces of soils.


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