Review: Weathering and Erosion

What is Mechanical Weathering?

What is Mechanical Weathering? When physical forces break rock into smaller pieces Does not change the rock’s composition Three Ways Frost Wedging Unloading Biological Activity

Mechanical Weathering: _________________?

Mechanical Weathering: Frost Wedging Water enters cracks and crevices in rocks Water freezes expanding the cracks Eventually breaking rock into pieces

Mechanical Weathering: _________________? The uplift and weathering of rocks overlying igneous rocks Why? Pressure on igneous rocks is reduced causing uplift ____________?: slabs of outer rock separate and break loose

Mechanical Weathering: Unloading The uplift and weathering of rocks overlying igneous rocks Why? Pressure on igneous rocks is reduced causing uplift Exfoliation: slabs of outer rock separate and break loose

Mechanical Weathering: _________________? Activities of living organisms Example: Plant roots wedge into rocks, breaking them apart

What is Chemical Weathering?

What is Chemical Weathering? Is the transfer of rock into one or more new compounds

Agents of Chemical Weathering _________? Most important agent Picks up gases from the atmosphere Causes oxidation of metal minerals Ex: rusting Carbon dioxide from respiration, sulfur dioxide and nitrogen oxides from burning fossil fuels Combines with water in the atmosphere to form acids like in acid rain

Agents of Chemical Weathering Water Most important agent Picks up gases from the atmosphere Oxygen Causes oxidation of metal minerals Ex: rusting Emissions Carbon dioxide from respiration, sulfur dioxide and nitrogen oxides from burning fossil fuels Combines with water in the atmosphere to form acids like in acid rain

Rate of Weathering What affects it?

Rate of Weathering What affects it? Rock Characteristics Mineral composition Mineral solubility Climate Temperature and moisture Favors high temperatures and abundant moisture

Surface area Topography (slope/gravity)

How is Soil Formed?

How is Soil Formed? Weathering of rocks that is carried away Factors Parent Material Time Climate Organisms Slope

Soil Texture Triangle 60 20 40 10 70 Percent Clay Percent Silt Percent Sand Texture Type 60 20 40 10 70

What is Erosion?

What is Erosion? Removal and transport of weathered material from one location to another

Agents of Erosion?

Agents of Erosion Running Water Wind Glaciers Ocean currents and Waves Biological Organisms

What happens to the Material? _________? Materials are dropped in another location Final stage of erosion

What happens to the Material? Deposition Materials are dropped in another location Final stage of erosion

What is a Glacier?

What is a Glacier? Large, moving mass of ice that forms near Earth’s poles and in mountainous regions at high elevations

How do Glaciers Erode Soil?

How do Glaciers Erode Soil? Scrape and gouge out large sections of landscape Can carry huge rocks and piles of debris over great distance

How can humans control erosion?

How can humans control erosion? Planting rows of trees called windbreakers Terracing hillsides Plowing along the contours of hills Rotating crops

What is Mass Movement?

What is Mass Movement? The transfer of rock and soil down-slope due to gravity

Triggers of Mass Movement

Triggers of Mass Movement Water Heavy rain and rapid snow melting saturate the surface Particles slide past one another easier Over-steepened Slopes The steeper the slope, the greater the chance for movement

Removal of Vegetation Earthquakes Roots keep soil intact Removing plants increase chances of movement and erosion Earthquakes Dislodge rocks and minerals

How to Classify Mass Movement? Classified by:

How to Classify Mass Movement? Classified by Kind of material moved How it moves Speed of movement

Types of Mass Movement

Types of Mass Movement Rock falls Slides Slumps Flows Avalanches Creep Rockslides Landslides Slumps Flows Mudflow Earthflow Avalanches Creep

Preventative Actions

Preventative Actions Dig series of trenches to divert running water Constructing protective fences on highways Retaining walls for weak slopes Don’t build on steep slopes

The Hydrosphere

Distribution of Water On Earth

Distribution of Water On Earth 71% of Earth is water 97% in the oceans 3% is freshwater 2% in ice and glaciers 0.6% in underground water 0.4% in rivers, streams, lake and atmosphere

Parts of the Water Cycle __________? liquid water changes into water vapor __________? liquid or solid water from the clouds __________? water vapor that turns into liquid making clouds __________? liquid water moving through the ground __________? water vapor released to the air by plants _______? when liquid hit the ground but not absorbed

Parts of the Water Cycle Evaporation: liquid water changes into water vapor Precipitation: liquid or solid water from the clouds Condensation: water vapor that turns into liquid making clouds Infiltration: liquid water moving through the ground Transpiration: water vapor released to the air by plants Runoff: when liquid hit the ground but not absorbed

The Water Cycle

How is Water Used? 70% in ______? 20% in ______? 10% in ______?

How is Water Used? 70% in Irrigation 20% in Industries 10% in Cities and Residences

How do Currents Influence Climate?

How do Currents Influence Climate? Exchanges heat in the water with the atmosphere Type of current nearby influences weather for an area Warm currents bring warm temperatures Cold currents bring cooler temperatures

Current Movement Warm Currents: ________________ Cold Currents: ________________

Current Movement Warm Currents Cold Currents Move from the tropics to the poles Ex: Gulf Stream (east coast of the US) Cold Currents Move from the poles to the equators Ex: Canary Current

Why do Current Moves? Primary Forces? Secondary Forces? The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of the earth, so only the horizontal component of the Coriolis force is generally important. This force causes moving objects on the surface of the Earth to be deflected in a clockwise sense (with respect to the direction of travel) in the Northern Hemisphere and in a counter-clockwise sense in the Southern Hemisphere. Rather than flowing directly from areas of high pressure to low pressure, as they would in a non-rotating system, winds and currents tend to flow to the right of this direction north of the equator and to the left of this direction south of it. This effect is responsible for the rotation of large cyclones

Why do Current Moves? Primary Forces Secondary Forces Start the movement Solar heating, winds, gravity, Coriolis Secondary Forces Influences where the current flows The Coriolis effect is caused by the rotation of the Earth and the inertia of the mass experiencing the effect. Because the Earth completes only one rotation per day, the Coriolis force is quite small, and its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of the earth, so only the horizontal component of the Coriolis force is generally important. This force causes moving objects on the surface of the Earth to be deflected in a clockwise sense (with respect to the direction of travel) in the Northern Hemisphere and in a counter-clockwise sense in the Southern Hemisphere. Rather than flowing directly from areas of high pressure to low pressure, as they would in a non-rotating system, winds and currents tend to flow to the right of this direction north of the equator and to the left of this direction south of it. This effect is responsible for the rotation of large cyclones

How does water become Groundwater? _____________? How easily water can pass through connected pore spaces ___________? Percentage of pore spaces in soil and rock Clay has the smallest percentage (not permeable)

How does water become Groundwater? Permeability How easily water can pass through connected pore spaces Porosity Percentage of pore spaces in soil and rock Clay has the smallest percentage (not permeable)

Groundwater Layers ________________? _______________? Area above the water table where water passes through Area where the soil, sediment and rock are saturated with water The upper level of the zone of saturation _______________? The water within the zone of saturation

Groundwater Layers Zone of Aeration Zone of Saturation The Water Table Area above the water table where water passes through Zone of Saturation Area where the soil, sediment and rock are saturated with water The Water Table The upper level of the zone of saturation Groundwater The water within the zone of saturation

Aquifers

Aquifers Underground layer of water bearing permeable rock (gravel, sand or silt) from which ground water can be extracted using a well

Wells A hole bored into the zone of saturation Pumping can cause the water table to be lowered Artesian Well?

Wells A hole bored into the zone of saturation Pumping can cause the water table to be lowered Artesian Well Groundwater rises on its own under pressure

Problems with Groundwater?

Problems with Groundwater Withdrawing water for agriculture Toxic metals contaminating the water (arsenic, cadmium, lead) Salt water intrusion Salt water from the ocean enters the groundwater near coastal areas

A Stream’s Profile ___________? __________? _________? At the beginning of a stream Usually at the mountains or higher elevations __________? At the end of a stream Usually at the ocean or another water body _________? A stream that empties into another stream

A Stream’s Profile Headwater Mouth Tributary At the beginning of a stream Usually at the mountains or higher elevations Mouth At the end of a stream Usually at the ocean or another water body Tributary A stream that empties into another stream

Watershed?

An area of land that contains a common set of streams and rivers Watershed An area of land that contains a common set of streams and rivers

Drainage Basins?

Is the land area that contributes water to a stream Drainage Basins Is the land area that contributes water to a stream

Results of Floods _____________? Area where water floods the land Provides a supplement of nutrient-rich silt to floodplain areas Recharges groundwater Kills and causes property damages

Results of Floods Floodplain Area where water floods the land Provides a supplement of nutrient-rich silt to floodplain areas Recharges groundwater Kills and causes property damages

How to control Floods? _______________? Concrete or Earthen mounds built on the banks of a river Increases the amount of water it can hold Parallels a stream and helps to contain its water, except during flood stage

How to control Floods? Artificial Levees Natural Levees Concrete or Earthen mounds built on the banks of a river Increases the amount of water it can hold Natural Levees Parallels a stream and helps to contain its water, except during flood stage

____________? Stores floodwater and lets it out slowly Preserve floodplains instead of building on them

Flood-Control Dams Limit Development Stores floodwater and lets it out slowly Limit Development Preserve floodplains instead of building on them

Human Activities Causing Flooding Removing vegetation Overgrazing Mining Building on floodplains Logging Forest fire Destruction of wetlands Urbanization

Human Activities Causing Flooding Removing vegetation Overgrazing Mining Building on floodplains Logging Forest fire Destruction of wetlands Urbanization

Types of Water Pollution __________________? Organic waste and manure _______________? Acids, arsenic, lead ________________? Nitrogen and phosphorus Oil, detergents, pesticides Erosion and soil

Types of Water Pollution Oxygen Demanding Agents Organic waste and manure Toxic Metals Acids, arsenic, lead Inorganic Plant Nutrients Nitrogen and phosphorus Organic Chemicals Oil, detergents, pesticides Sediment Erosion and soil

Oxygen Demanding Agents __________? is removed from water by bacteria (B.O.D) Fish can’t live in streams without _________?

Oxygen Demanding Agents Oxygen is removed from water by bacteria (B.O.D) Fish can’t live in streams without oxygen

_______________? #1 source of water pollution Clouds the water Blocks sunlight for the aquatic plants

Sediment #1 source of water pollution Clouds the water Blocks sunlight for the aquatic plants

Protecting The Water __________________? Regulates the discharge of pollutants in the US river and streams Protect the quality of drinking water Water treatment plants Well water

Protecting The Water Clean Water Act (1972) Regulates the discharge of pollutants in the US river and streams Safe Drinking Water Act (1974) Protect the quality of drinking water Water treatment plants Well water

Water Conservation Methods

Water Conservation Methods Repair leaking faucets and pipes Landscape using plants requiring little water Use drip irrigation Use water saving appliances Purify and reuse water