Rain Shadow Effect
Rain shadow: windward = wet (air rises, cools, rains). Leeward = dry.
Rain Shadow Effect
Mountains create wet and dry sides by forcing air upward
Moist air hits mountain, rises, cools, precipitates → wet windward side. Air descends on the other side dry and warm → rain shadow desert. Sierra Nevada → Death Valley.
River System Parts
River: Source → Tributary → Meander → Delta — STMD
River System Parts
Four key features from mountain source to ocean mouth
Source: where river begins (high elevation). Tributary: smaller stream feeding in. Meander: curve/bend on flat terrain. Delta: sediment fan where river meets sea.
Biome Latitude Zones
Biome latitude zones: Tropical → Desert → Temperate → Boreal → Tundra
Biome Latitude Zones
Biomes arrange from equator to poles by temperature and rainfall
Tropical rainforest (0-15°): hot and wet. Subtropical desert (15-30°): hot and dry. Temperate forest (30-60°): seasons. Boreal/taiga (60-70°): cold, coniferous. Tundra (70-90°): frozen.
Plate Boundary Landforms
Tectonic landforms: divergent = ridge/rift, convergent = trench/mountain, transform = fault
Plate Boundary Landforms
What landforms each boundary type creates
Divergent: mid-ocean ridges, rift valleys. Convergent (ocean-continent): trenches, volcanic mountains. Convergent (continent-continent): fold mountains like Himalayas. Transform: fault lines, earthquakes.
Soil Profile
Soil horizons: O (organic) → A (topsoil) → B (subsoil) → C (parent material) → R (bedrock)
Soil Profile
Soil forms in distinct layers — each with different properties
O horizon: surface organic matter (leaves, humus). A horizon: topsoil — most fertile, highest organic content. B horizon: subsoil — accumulation of clay and minerals. C horizon: weathered parent rock. R: bedrock.
Weathering vs Erosion
Weathering: mechanical (breaks rock apart) vs chemical (changes rock composition). Erosion = transport of weathered material.
Weathering vs Erosion
Two processes that reshape Earth's surface — often confused
Mechanical weathering: breaks rock into smaller pieces without changing its chemical composition. Freeze-thaw (frost wedging), thermal expansion, root wedging. Chemical weathering: changes the minerals — oxidation (rust), hydrolysis, carbonation (acid rain on limestone). Erosion: the removal and transport of weathered material by water, wind, ice, or gravity.
Glacial Landforms
Glacial features: U-shaped valleys (glaciers), V-shaped valleys (rivers). Moraines = deposited debris.
Glacial Landforms
How glaciers sculpt the landscape differently from rivers
Glaciers carve U-shaped valleys (wide, flat-bottomed). Rivers carve V-shaped valleys (narrow, pointed bottom). Cirque: bowl-shaped depression where glacier forms. Arête: sharp ridge between two cirques. Horn: pyramidal peak (Matterhorn). Moraine: ridge of debris deposited by glacier. Drumlin: teardrop-shaped hill of glacial till.
Watersheds and Drainage Basins
Watershed: all land draining to a common outlet. Continental divide separates drainage basins.
Watersheds and Drainage Basins
How water flows through landscapes
Watershed (drainage basin): all land area that drains to a common river, lake, or ocean outlet. Continental divide: ridge separating drainage toward different oceans. In North America: Rocky Mountains divide Pacific drainage from Atlantic/Gulf drainage. Mississippi watershed: ~40% of continental US.
Coastal Landforms
Coastal features: beaches (deposition), cliffs (erosion), spits (longshore drift), deltas (river deposition)
Coastal Landforms
How waves, currents, and rivers shape coastlines
Erosional coastlines: cliffs, sea arches, sea stacks, wave-cut platforms. Depositional coastlines: beaches, spits (sand bar extending from headland), tombolo (sand bar connecting island to mainland), barrier islands. Longshore drift: sediment moves along coast parallel to shore due to wave angle.
The Rock Cycle
Rock cycle: igneous → sedimentary → metamorphic → back to igneous. Heat, pressure, weathering drive it.
The Rock Cycle
How all three rock types transform into each other over geological time
Igneous: magma cools (intrusive = granite, extrusive = basalt). Weathering → sediment → compaction/cementation → sedimentary rock. Burial + heat/pressure → metamorphic rock. Further heat → melts → magma again. No rock is permanent — all eventually cycle through.
Natural Hazard Types
Natural hazards: endogenic (earthquakes, volcanoes — from within Earth) vs exogenic (floods, hurricanes — surface processes)
Natural Hazard Types
Two categories of natural hazards based on their origin
Endogenic: driven by internal Earth energy. Earthquakes: fault movement, plate boundaries. Volcanoes: magma eruption, hotspots and plate boundaries. Exogenic: driven by solar energy and water cycle. Floods: excessive precipitation or snowmelt. Hurricanes: warm ocean water + atmospheric conditions. Droughts: rainfall deficits.
Latitude and Climate
Latitude affects climate most: equatorial (hot, wet), subtropical (dry), temperate (seasonal), polar (cold)
Latitude and Climate
The most fundamental control on global climate patterns
Solar angle decreases with latitude → less energy per unit area → cooler. At equator: sun almost directly overhead year-round → consistent heat. At poles: sun at low angle, no summer warmth → cold year-round. Seasons caused by Earth's axial tilt (23.5°) — not distance from sun.