| A | B |
|---|
| plate tectonics | theory that the continents move on large plates of rock |
| fault lines | breaks in the earth's crust |
| erosion | slow wearing away of soil and rocks by glaciers, running water, wind or waves |
| fossils | remains of plants and animals from long ago, preserved in rock |
| deltas | triangular-shaped plains of sediment where rivers flow into large bodies of water |
| climate | average weather at a place over time |
| Tropic of Cancer | latitude 23.5 degrees N that marks northern boundary of the Tropics |
| Tropics | the region between the Tropics of Cancer and Capricorn, where temperatures remain hot all year |
| tropical savanna climate | alternates between rainy and dry seasons |
| Mediterranean climate | hot, dry summers and mild, rainy winters |
| humid subtropical climate | cool, rainy summers and mild, rainy winters |
| dry climate | found within the temperate latitudes and near the tropical latitudes |
| steppe climate | not as dry as desert climates; sometimes called semiarid regions |
| subarctic climate | very cold but warm enough for trees to grow |
| highlands climate | determined by elevation -- the higher a place is, the colder and windier |
| precipitation | hail, mist, rain, sleet, or snow |
| forest | tall, woody vegetation that exists in highland, temperate, and tropical climates |
| deciduous forests | trees that shed their leaves in autumn; found in temperate climates |
| grasslands | vegetation that exists in highland, temeprate, and tropical climates |
| dry temperate grasslands | grasslands well suited for grazing |
| desert | very dry, barren land |
