Unit 4 · Earth Systems and Resources

Convergent plate boundaries ● (core concept) — Convergent plate boundaries can result in the creation of mountains, island arcs, earthquakes, and volcanoes.

Divergent plate boundaries ● (core concept) — Divergent plate boundaries can result in seafloor spreading, rift valleys, volcanoes, and earthquakes.

Transform plate boundaries ● (core concept) — Transform plate boundaries can result in earthquakes.

Plate boundary maps ● (core concept) — 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.

Earthquake mechanism ● (core concept) — An earthquake occurs when stress overcomes a locked fault, releasing stored energy.

Soil formation ● (core concept) — Soils are formed when parent material is weathered, transported, and deposited.

Soil horizons ● (core concept) — Soils are generally categorized by horizons (layers) based on their composition and organic material.

Soil erosion and water filtration ● (core concept) — 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.

Water holding capacity ● (core concept) — 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.

Particle size and soil properties ● (core concept) — The particle size and composition of each soil horizon can affect the porosity, permeability, and fertility of the soil.

Soil testing ● (core concept) — There are a variety of methods to test the chemical, physical, and biological properties of soil that can aid in decisions such as irrigation and fertilizer requirements.

Soil texture triangle ● (core concept) — A soil texture triangle is a diagram that allows for the identification and comparison of soil types based on their percentages of clay, silt, and sand.

Loam ● (core concept) — Loam consists of a blend of clay, silt, and sand that can support a variety of crops.

Composition of the atmosphere ● (core concept) — The atmosphere is made up of major gases, each with its own relative abundance.

Layers of the atmosphere ● (core concept) — The layers of the atmosphere are based on temperature gradients and include the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

Causes of global wind patterns ● (core concept) — Global wind patterns primarily result from the most intense solar radiation arriving at the equator, resulting in density differences and the Coriolis effect.

Watershed ● (core concept) — A watershed is an area of land that drains into a common body of water. Characteristics of a given watershed include its area, length, slope, soil, vegetation types, and divides with adjoining watersheds.

Insolation ● (core concept) — Incoming solar radiation (insolation) is the Earth's main source of energy and is dependent on season and latitude.

Solar angle and radiation intensity ● (core concept) — 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.

Latitudinal radiation gradient ● (core concept) — The highest solar radiation per unit area is received at the equator and decreases toward the poles.

Seasonal variation in solar radiation ● (core concept) — 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.

Earth's axial tilt and seasons ● (core concept) — 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.

Geographic factors in climate ● (core concept) — Weather and climate are affected not only by the sun's energy but by geologic and geographic factors, such as mountains and ocean temperature.

Rain shadow ● (core concept) — A rain shadow is a region of land that has become drier because a higher elevation area blocks precipitation from reaching the land.

El Nino and La Nina (ENSO) ● (core concept) — El Nino and La Nina are phenomena associated with changing ocean surface temperatures in the Pacific Ocean (the El Nino-Southern Oscillation). These phenomena can cause global changes to rainfall, wind, and ocean circulation patterns.

Variable effects of ENSO ● (core concept) — El Nino and La Nina are influenced by geological and geographic factors and can affect different locations in different ways.