Earth Science Exam 2: Unit 2 Review

Flashcards created for review of Earth Science concepts, covering stages of the hydrologic cycle, soil properties, glacial processes, and agricultural practices.

What are the main processes of the hydrologic cycle?

Infiltration, evaporation, transpiration, and runoff.

What happens during infiltration?

Precipitation reaches the ground and seeps into the soil water, becoming part of underground aquifers.

Define runoff in the context of the hydrologic cycle.

Precipitation that does not infiltrate the ground and flows into bodies of water like lakes, rivers, and oceans.

What is transpiration?

The process where plants absorb water from the soil and release it as vapor through tiny pores in their leaves.

What factors affect soil erosion during streamflow?

Gradient or slope, and channel characteristics including shape, size, and roughness.

What is dissolved load in a river?

Tiny particles dissolved in water, such as salts or minerals, which are too small to see.

What is suspended load?

Lightweight particles like silt and clay that float in water, making it appear cloudy.

Differentiate between bed load and dissolved load.

Bed load consists of larger, heavier particles like sand and gravel that move along the riverbed, while dissolved load includes tiny particles dissolved in water.

What determines a stream's competence?

The stream's velocity.

What is alluvium?

Stream sediments.

Define a delta.

A body of sediment where a stream enters a lake or the ocean.

What is a yazoo tributary?

A smaller stream that runs alongside a main river instead of merging with it.

Explain what backswamps are.

Swampy areas found behind natural levees along a river.

What are levees?

Structures formed parallel to the stream channel by successive floods over many years.

Define an oxbow lake.

A U-shaped lake formed when a river takes a shortcut and cuts off a bend.

What is a dendritic drainage pattern?

A pattern where streams flow in many directions, resembling tree branches.

Describe a trellis drainage pattern.

A pattern where streams follow valleys and ridges in folded terrain.

What is a sinkhole?

A surface depression formed by dissolving bedrock and cave collapse.

Differentiate between stalactites and stalagmites.

Stalactites grow downward from a ceiling, while stalagmites grow upward from the ground.

What percentage of Earth's freshwater is stored in glaciers?

84% is stored in ice sheets and glaciers.

What is a Valley glacier?

A glacier that flows down a valley from an accumulation center at its head.

What are the vertical and lateral layers of a glacier?

Vertical layers: Top (Snow), Middle (Ice), Bottom (Dirt). Lateral layers include medial moraines and lateral moraines.

Define plucking in terms of glacial processes.

The lifting of rocks by a glacier.

What is calving?

The breaking off of large pieces of ice from a glacier.

Differentiate between glacial till and stratified drift.

Glacial till consists of unsorted sediments, while stratified drift has sorted sediment deposited by meltwater from a glacier.

What causes scratches or striations on rock surfaces?

Striations are formed by glaciers as they move, indicating the direction of glacier movement.

Which types of moraines can form via alpine glaciers?

Lateral moraine and medial moraine.

What are drumlins?

Smooth, elongated, parallel hills formed by glacial activity.

Define a steppe.

A dry, grassy plain with low vegetation and more rainfall than deserts.

How much of Earth's surface is classified as drylands?

30% of Earth's surface is considered drylands.

What occurs on the windward side of a mountain range?

Rainfall occurs on this side.

What is the leeward side known for?

It experiences the rain shadow effect, creating a drier area.

Define an ephemeral stream.

A stream that carries water only during periods of rainfall.

What is saltation in terms of wind erosion?

The skipping and bouncing of particles along the surface.

Define deflation.

The lifting of loose materials due to wind.

Describe the shape of a sand dune.

Mounds or ridges of sand that are often asymmetrical.

What are the five golden rules of agriculture to preserve soil?

1. Cover the soil 2. Minimal or zero tillage 3. Mulch for nutrients 4. Maximize biomass production 5. Maximize biodiversity.

What is salinization?

The process caused by too much salt, making it hard for plants to grow.

Describe the layers of soil and their characteristics.

O Horizon: Organic layer, very fertile. A Horizon: Topsoil, fertile mineral and organic mix. E Horizon: Eluviation layer, leached, less fertile. B Horizon: Subsoil, accumulates minerals, less organic. C Horizon: Parent material, weathered rock, minimal fertility.

What are three soil particle types and their relative sizes?

Sand - large, Silt - small, Clay - smallest.

What is the composition of a loam soil?

40% sand, 40% silt, 20% clay.

What characterizes the best soil type for water and nutrient retention?

Loam is the best overall soil type.

What are mollisols known for?

They are the best agricultural soils.

Describe oxisols.

They are poor agricultural soils.

What factors contribute to healthy soil?

1. Good nutrient supply 2. Good water-holding capacity 3. Porous structure for aeration 4. Near-neutral pH 5. Low salt content.

What is detritus?

Dead organic matter.

What are major factors leading to soil loss?

Erosion, desertification, overcultivation, overgrazing, deforestation.

How does deforestation contribute to soil loss?

It leads to loss of soil protection and increases erosion, making land less fertile.

Differentiate between splash, sheet, and gully erosion.

Splash erosion dislodges small particles. Sheet erosion decreases infiltration and results in runoff. Gully erosion creates streams and gullies that transport large quantities of soil.

What is no-till farming?

A method where planting is done directly in plant residues, preserving soil health and reducing erosion.

Explain how desertification occurs due to wind erosion.

Wind blows away the top layer of soil, leading to nutrient loss and creating dry, barren land.