APES unit 4 AHS

Core → Mantle → Asthenosphere → Lithosphere → Crust

Dense metallic center made of iron, nickel, and radioactive elements that generate heat driving mantle convection

Thick layer of semi-solid rock where convection currents circulate magma and move tectonic plates

Plastic, semi-molten zone of the upper mantle that allows tectonic plates to float and shift

Rigid outer shell made of crust and upper mantle, broken into tectonic plates

Thin rocky outermost layer of Earth, containing continents and ocean basins

Plates move apart as rising magma pushes through, forming new crust

Mid-ocean ridges, volcanoes, seafloor spreading zones, and continental rift valleys

Plates collide, causing subduction or uplift, forming major geologic features

Mountains, trenches, island arcs, coastal volcanoes, earthquakes

Plates slide horizontally past each other, creating friction and frequent earthquakes

Heat from the core causes magma to rise, cool, sink, and continuously circulate

Rising magma pushes plates apart; sinking material pulls plates downward at subduction zones

Both plates uplift to form large, non-volcanic mountain ranges (e.g., Himalayas)

Dense oceanic plate subducts, melting into magma that rises to form volcanic mountain chains (e.g., Andes)

One plate subducts beneath another, forming volcanic island arcs (e.g., Japan)

Stored friction energy releases suddenly, producing earthquakes (e.g., San Andreas Fault)

Volcano created by rising plumes of magma in the mantle, independent of plate boundaries

Circular zone around the Pacific with intense volcanic and earthquake activity due to subduction zones

O Horizon → A Horizon → B Horizon → C Horizon

Top layer made of organic material such as leaves, biomass, and decomposed matter (humus)

Mix of humus and minerals, richest layer for plant growth and biological activity

Zone of mineral accumulation with fewer organics; often contains iron, aluminum, or clay

Partially weathered parent material, foundation for soil formation

Complex mixture of minerals, organic matter, air, water, and living organisms that supports ecosystems

Sand, silt, clay, humus, water, air pockets, microorganisms, and nutrient ions

Provides plant anchorage, filters water, recycles nutrients, and supports diverse organisms

Mechanical breakdown of rock by wind, water, temperature changes, or abrasion

Organisms (roots, bacteria, burrowing animals) break rock into smaller pieces

Chemical reactions such as oxidation or acid rain dissolve minerals in rock

Weathering of bedrock creates mineral particles (sand, silt, clay)

Decomposition of plants and organisms forms humus, adding nutrients and improving structure

Parent material, topography, climate, organisms, and time all shape soil characteristics

Topsoil loss from erosion, compaction, nutrient depletion, and unsustainable farming

Reduces pore space, decreases infiltration, increases runoff, harms root growth

Repeated cropping removes essential nutrients such as nitrogen, phosphorus, potassium, magnesium, and calcium

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

Percentage of sand, silt, and clay that determine soil structure and properties

Balanced mixture of 40% sand, 40% silt, 20% clay

Porosity is pore space; permeability is how easily water flows through pores

Large particles create large pores, allowing fast drainage and low water retention

Small particles create tiny pores, causing slow drainage but high nutrient-holding ability

High humus content, decomposer activity, adequate clay, and presence of base minerals like calcium carbonate

Acidic soil, erosion, chemical overuse, irrigation-driven salinization, and nutrient mining

Jar test separates sand, silt, and clay based on settling speed

Timed water infiltration test showing drainage rate

Determines acidity or alkalinity, affecting nutrient availability

NPK tests identify nitrogen, phosphorus, and potassium levels

78% nitrogen, 21% oxygen, 0.93% argon, 0.04% CO₂, variable water vapor

Lowest layer where weather occurs and greenhouse gases are concentrated

Contains the ozone layer, absorbs UV radiation, temperature increases with altitude

Coldest layer; meteors burn up here

Hottest layer; contains auroras; thin air

Outer atmospheric layer gradually transitioning into space

Temperature decreases as altitude increases

Ozone absorbs UV radiation

Temperature decreases with height

Solar radiation absorption

Rises, expands, and holds more water vapor

Sinks, compresses, and holds less moisture

0–30° latitude with rising equatorial air and sinking dry air at 30°

30–60° with mid-latitude westerly winds

60–90° with cold, sinking air at the poles

Rising air = low pressure; sinking air = high pressure

Earth’s rotation deflects winds and currents—rightward in the Northern Hemisphere, leftward in the Southern

East-to-west surface winds between 0–30°

West-to-east winds between 30–60°

Area of land where all water drains into a common body of water

Slope, vegetation density, and soil type determine infiltration vs runoff

Large estuary mixing salt and fresh water, providing habitat and nutrient filtration

Loss of plant roots increases erosion and topsoil loss

Higher sediment levels, more turbidity, reduced shade → warmer water

Incoming solar radiation received by Earth

Sun angle, atmospheric path length, season, and latitude

23.5° axial tilt changes sunlight angle and day length

Snow, glaciers; they reflect sunlight and stay cool

Water, asphalt; they absorb heat and warm quickly

Cities heat up due to low albedo surfaces and reduced vegetation

Equator is warm/wet; 30° zones are dry deserts

Moist air rains on windward side; dry air descends on leeward side

Cold, nutrient-rich water rises, boosting marine productivity

Large circular ocean currents driven by global winds

Global conveyor belt driven by differences in temperature and salinity

Strong trade winds push warm water west, causing upwelling off South America

Trade winds weaken, warm water shifts east, upwelling drops

Trade winds strengthen, increasing upwelling near South America

Flooding in Americas, fishery collapse, drought in Australia/Indonesia, fewer Atlantic hurricanes

Stronger fisheries, more Atlantic hurricanes, wetter Australia, cooler/drier Americas