Unit 4: Earth Systems and Resources

Describe the geological changes and events that occur at convergent, divergent, and transform plate boundaries.

• Convergent boundaries can result in the creation of mountains, island arcs, earthquakes, and volcanoes.
• Divergent boundaries can result in seafloor spreading, rift valleys, volcanoes, and earthquakes.
• Transform boundaries can result in earthquakes.
• Maps that show the global distribution of plate boundaries can be used to determine the location of volcanoes, island arcs, earthquakes, hot spots, and faults.
• An earthquake occurs when stress overcomes a locked fault, releasing stored energy.
• Enduring understanding ERT-4: Earth’s systems interact, resulting in a state of balance over time.

Describe the characteristics and formation of soil.

• Soils are formed when parent material is weathered, transported, and deposited.
• Soils are generally categorized by horizons based on their composition and organic material.
• Soils can be eroded by winds or water. Protecting soils can protect water quality as soils effectively filter and clean water that moves through them.
• Enduring understanding ERT-4: Earth’s systems interact, resulting in a state of balance over time.

Describe similarities and differences between properties of different soil types.

• Water holding capacity—the total amount of water soil can hold—varies with different soil types. Water retention contributes to land productivity and fertility of soils.
• The particle size and composition of each soil horizon can affect the porosity, permeability, and fertility of the soil.
• There are a variety of methods to test the chemical, physical, and biological properties of soil that can aid in a variety of decisions, such as irrigation and fertilizer requirements.
• A soil texture triangle is a diagram that allows for the identification and comparison of soil types based on their percentage of clay, silt, and sand.
• Enduring understanding ERT-4: Earth’s systems interact, resulting in a state of balance over time.

Describe the structure and composition of the Earth’s atmosphere.

• The atmosphere is made up of major gases, each with its own relative abundance.
• The layers of the atmosphere are based on temperature gradients and include the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
• Enduring understanding ERT-4: Earth’s systems interact, resulting in a state of balance over time.

Explain how environmental factors can result in atmospheric circulation.

• Global wind patterns primarily result from the most intense solar radiation arriving at the equator, resulting in density differences and the Coriolis effect.
• Enduring understanding ERT-4: Earth’s systems interact, resulting in a state of balance over time.

Describe the characteristics of a watershed.

• Characteristics of a given watershed include its area, length, slope, soil, vegetation types, and divides with adjoining watersheds.
• Enduring understanding ERT-4: Earth’s systems interact, resulting in a state of balance over time.

Explain how the sun’s energy affects the Earth’s surface.

• Incoming solar radiation (insolation) is the Earth’s main source of energy and is dependent on season and latitude.
• The angle of the sun’s rays determines the intensity of the solar radiation. Due to the shape of the Earth, the latitude that is directly horizontal to the solar radiation receives the most intensity.
• The highest solar radiation per unit area is received at the equator and decreases toward the poles.
• The solar radiation received at a location on the Earth’s surface varies seasonally, with the most radiation received during the location’s longest summer day and the least on the shortest winter day.
• The tilt of Earth’s axis of rotation causes the Earth’s seasons and the number of hours of daylight in a particular location on the Earth’s surface.
• Enduring understanding ENG-2: Most of the Earth’s atmospheric processes are driven by input of energy from the sun.

Describe how the Earth’s geography affects weather and climate.

• Weather and climate are affected not only by the sun’s energy but by geologic and geographic factors, such as mountains and ocean temperature.
• A rain shadow is a region of land that has become drier because a higher elevation area blocks precipitation from reaching the land.
• Enduring understanding ENG-2: Most of the Earth’s atmospheric processes are driven by input of energy from the sun.

Describe the environmental changes and effects that result from El Niño or La Niña events (El Niño–Southern Oscillation).

• El Niño and La Niña are phenomena associated with changing ocean surface temperatures in the Pacific Ocean. These phenomena can cause global changes to rainfall, wind, and ocean circulation patterns.
• El Niño and La Niña are influenced by geological and geographic factors and can affect different locations in different ways.
• Enduring understanding ENG-2: Most of the Earth’s atmospheric processes are driven by input of energy from the sun.