Unit 4 - earth systems and resources Flashcards
core
dense mass of solid nickel, iron, and radioactive elements that release massive amount of heat
mantle
liquid layer of magma surrounding core, kept liquified by intense heat from core
asthenosphere
solid flexible outer layer of mantle, beneath the lithosphere
lithosphere
thin, brittle layer of rock floating on top of mantle (broken up into tectonic plates)
crust
very outer layer of the lithosphere, earths surface
divergent plate boundaries
- plates moving away from each other
- rising magma plume from mantle forces plates apart
what do divergent plate boundaries form
rising magma plume forces plates apart forming
- mid oceanic ridges
- volcanoes
- seafloor spreading
- rift valleys (on land)
convergent plate boundaries
- plates move towards each other
- leads to subduction (one plate being forced beneath another)
what do convergent plate boundaries form
subduction forms
- mountains
- island arcs
- earthquakes
- volcanoes
transform plate boundaries
- plates slide past each other in opposite directions
what do transform plate boundaries form
earthquakes
tectonic map can predict
ring of fire, transform faults, hotspots
ring of fire
pattern of volcanoes all around pacific plate
- offshore island arcs (japan)
where are there offshore island arcs
Japan
transform faults
likely location of earthquakes
hotspots
areas of especially hot magma rising up to lithospheres
- mid ocean islands (iceland, hawaii)
where are there hotspots
Iceland, Hawaii
what is soil?
mix of geologic (rock) and organic (living) components
- sand, silt, clay
- humus
- nutrients
- water & air
- living organisms
humus
main organic part of soil (broken down biomass like leaves, dead animals, waste)
what does soil do for plants
anchors roots of plants and provides water, shelter, nutrients for growth
what does soil do for water
filters rainwater and runoff by trapping pollutants in pore spaces and plant roots. clean water enters groundwater and aquifiers
what does soil do for nutrient recycling
home to decomposers that break down dead organic matter and return nutrients to the soil
what does soil do for habitat
provides habitat for organisms like earthworms, fungi, bacteria, moles, slugs
weathering vs erosion
weathering is the break down and erosion is the movement
soil horizon: o
organic
- litter layer
- organic matter deposited by organisms
soil horizon: a
topsoil
- some organic material mixed with mineral components
soil horizon: b
subsoil
- minerals and organic matter accumulate here
soil horizon: c
weathered rock
- initial step in soil formation
soils are formed when
parent material is weathered, transported, and deposited
soils are generally categorized by
horizons based on their composition and organic material
soils can be eroded by
winds or water
loss of topsoil
- tilling + loss of vegetation disturbs soil and make it more easily eroded by wind + rain.
- loss of topsoil dry’s out soil, removes nutrients + soil organisms that recycle nutrients
compaction
compression of soil by machines (tractors, bulldozers), grazing livestock, and humans reduces ability to hold moisture
- dry soil erodes more easily
- dry soil supports less plant growth, less root structure
tilling
turning soil for agriculture
nutrient depletion
repeatedly growing crops on the same soil removes key nutrients (N, P, K, Na, Mg) over time; reduces ability to grow future crops