AP Environmental Unit 4 MCQ

Layers of the Earth

Crust, Mantle, Outer Core, Inner Core.

Distance from surface to core

About 6,400 km (4,000 miles).

Core

Innermost zone made of iron and nickel; liquid outer layer and solid inner layer.

Mantle Layer

above the core containing magma; convection moves plates.

Crust

Chemically distinct outermost layer of the lithosphere.

Hot spot

Place where molten material from Earth’s mantle reaches the lithosphere, forming volcanoes like Hawaii.

Theory of plate tectonics

Earth’s lithosphere is divided into moving plates driven by mantle convection.

Divergent boundary

Plates move apart and new crust forms.

Convergent boundary

Plates collide and one subducts beneath the other.

Transform fault boundary

Plates slide past each other horizontally.

Richter scale

Measures earthquake strength; each whole number is 10 times greater than the last.

Three types of rock

Igneous (from magma), Sedimentary (from compressed sediments, holds fossils), Metamorphic (from heat and pressure).

Difference between weathering and erosion

Weathering breaks down rock in place; erosion moves the broken material.

Physical weathering

Mechanical breakdown by wind, water, ice, or plant roots.

Chemical weathering

Breakdown by chemical reactions like acid rain or oxidation.

Services provided by soil

Supports plant growth, filters water, provides habitat, and filters pollutants.

Soil horizons

O = organic layer, A = topsoil, E = leaching zone, B = minerals, C = parent material.

Reading a soil triangle

Use the percentages of sand, silt, and clay to find soil texture class.

Sediment sizes

Sand (largest), silt (medium), clay (smallest).

Porosity

Amount of pore space; controls water-holding ability.

Types of surface mining

Strip, open-pit, mountaintop removal, and placer mining.

Acid mine drainage

Acidic water runoff from mines that pollutes soil and streams.

Percent of Earth’s freshwater

Less than 3 percent of all water; under 1 percent is usable.

Water table

Upper level where the ground is fully saturated with water.

Aquifer

Permeable rock layer that stores and transmits groundwater.

Well

A hole drilled to reach groundwater.

Spring

Natural flow of groundwater to Earth’s surface.

Cone of depression

Lowering of the water table around a heavily pumped well.

Artesian well

Water rises naturally from a confined aquifer due to pressure.

Saltwater intrusion

Seawater enters freshwater aquifers from over-pumping near coasts.

Ogallala Aquifer

Largest U.S. aquifer; declining from heavy irrigation use.

Floodplain

Flat area next to a river that floods and deposits nutrients.

Levee

Bank built along rivers to prevent flooding.

Dike

Structure that keeps ocean water from flooding land.

Dam

Barrier that controls river flow, creates reservoirs, and stores water.

Aqueduct

Pipe or canal that transports water from one location to another.

Aral Sea and aqueduct connection

Rivers feeding the Aral Sea were diverted for irrigation through aqueducts, shrinking the sea by about 60 %.

Impermeable surfaces

Pavement or buildings that stop water infiltration and increase runoff.

Percent of freshwater used for agriculture

About 70 percent of global freshwater use.

Types of irrigation

Furrow, flood, spray, and drip.

Efficiency of irrigation methods

Furrow and flood = low; spray = moderate; drip = most efficient.

Hydroponic agriculture

Growing plants in nutrient-rich water; uses up to 95 % less water.

Most water use in homes

Toilets use the most indoor water.

Gray water

Water from sinks, showers, and washers reused for irrigation or toilets.