AP Environmental Science Unit 4 Essentials

The slow movement of lithospheric plates over the mantle — at convergent, divergent, and transform boundaries — explains the location of almost every major volcano, earthquake zone, and mountain range on Earth. This single framework lets you predict where geologic hazards are most likely to occur and explains why certain regions (like the Pacific "Ring of Fire") experience disproportionate volcanic and seismic activity.

Because the equator receives more direct sunlight than the poles, warm air rises near the equator and sinks at higher latitudes, creating circulation cells. Earth's rotation then bends these moving air masses via the Coriolis effect, producing the predictable global wind belts that, in turn, drive weather patterns and influence where major biomes and deserts form (a connection back to Unit 1).

Soil formation depends on geology (parent rock), climate, and time working together over centuries — yet it can be stripped away by erosion in a matter of years if mismanaged. Likewise, a watershed concentrates the consequences of land use across an entire drainage area into a single waterway. Both ideas set up the human-impact units later in the course (Land & Water Use, Pollution) by showing how physical Earth systems translate directly into resource availability and vulnerability.