Chapter IV Flashcards
earth’s center, where pressures and temperatures are very high
core
the section of earth’s interior that lies above the outer core and has the most mass
mantle
liquid rock within earth
magma
the theory that earth’s crust is divided into rigid plates that slowly move across the upper mantle
plate tectonics
the process by which earth’s plates slowly move across the upper mantle
continental drift
places on earth’s surface where the crust stretches until it breaks
rift valleys
areas of the ocean floor where rocks gradually sink, because they have no supporting heat below them; the world’s flattest and smoothest regions
abyssal plains
areas where continental surfaces extend under the shallow ocean water around the continents
continental shelves
a deep valley marking a collision of plates, where one plate slides under another
trench
places where rocks have been compressed into bends by colliding plates
folds
places where rock masses have been broken apart and are moving away from each other
faults
the process by which rocks break and decay over time
weathering
small particles if weathered rock
sediment
process of removing salt from ocean water
desalinization
movement of water through the hydrosphere
hydrologic cycle
first and smallest streams formed form the runoff of a mountain, eventually forming rivers
headwaters
any smaller stream or river that flows into a larger stream or river
tributary
the entire region drained by a river and its tributaries
watershed
a region drained by a river and its tributaries
drainage basin
semi-enclosed bodies of water, seawater, and freshwater formed where a river meets an inlet of the sea
estuaries
landscapes that are covered with water for at least part of the year
wetlands
broken down plant and animal matter in soil
humus
downward movement of minerals and humus in soils
leaching
plowing fields across a hill, rather than up or down the hill
contour plowing
a condition in which soil has lost nutrients and becomes nearly useless for farming
soil exhaustion
the practice of planting different crops in a field in alternating years
crop rotation
a process in which water is artificially supplied to the land
irrigation
salt buildups in the soil
soil salinization
destruction or loss of forests
deforestation
the replanting of a forest
reforestation
artificial channels for transporting water
aqueducts
rock layers where groundwater is plentiful
aquifers
groundwater that is not replenished by rain
fossil fuels
