Structure of the Earth Flashcards
inner core
solid because there is a lot of pressure there. it is a hot dense iron ball, that is almost the size of the moon and spins faster than the earth’s surface, which creates a magnetic field
outer core
liquid made of iron and nickel. it is very thick and extremely hot. because the outer core moves around the inner core, earths magnetism is created.
mantle
dense liquid, molten rock and magma. the upper mantle is solid but the lower is liquid, it is extremely hot and has a lot of pressure
crust
solid, broken in 12 main plates, as they are floating in the liquid they move. there are 2 types of crusts, the oceanic and the continental. the oceanic is thin, very dense and has lots of pressure, the continental is very thick and very dense
tectonic plates
The crust is broken into large pieces called tectonic plates. These huge pieces of Earth’s surface slowly move and cause the natural disasters we call volcanos and earthquakes
convection currents
the core is very hot and the mantle is liquid, this means that when you heat this liquid, the molecules will expand, increase in energy and become less dense, therefore it rises. when it rises, it can either push though (where it will form volcanoes, etc.) or go it does not get though and have to go in separate ways in a circle form. the molecules will then cool down, loose energy, become more dense, and therefore drop.
what leads to plate movement
convection currents underneath the plates cause them to move together, side to side or being pulled apart. the places where they meet, are where the volcanoes, islands, mountains, etc are formed
constructive/divergent plate boundary
when 2 plates are pulling apart, magma rises up creating shield volcanoes, islands
consequences of divergent movement
islands
volcanoes
earthquakes
examples of divergent movement
North America vs Eurasian
Australian vc Antartican
destructive/convergent plate boundary
when oceanic ant continental plate move towards each other. the oceanic is thinner and denser than continental, therefore, they move towards each other on the oceanic sinks underneath the less dense crust.
consequences of convergent movement
volcanoes
earthquakes
mountains
examples of convergent movement
Nasca vs South American
conservative plate boundary
when plates are moving along side each other, however they have different speeds or even opposite directions, when these plates stops, it causes eathquakes
consequences of conservative movement
earthquakes
faults
examples of conservative movement
North American vs Pasific
African vs Australian
collisional plate boundary
when 2 continental plates of the same density colide, neither of them can sink so it creates mountains as it pushes towards each other
consequences of collisional movement
earthquakes
mountains
examples of collisional movement
Eurasian vc Indo Australian
shield volcanoes
lava is alkaline, and runny, it is wide, broad and domed shaped
composite volcanoes
lava is thinners and acid, it is cone shaped and has steep sides
volcanic explosive index
a scale that describes the size of explosive volcanic eruptions based on magnitude and intensity
advantages of living near volcanoes
fertile soil
tourist attractions
minerals
hot springs
heat can be used for elec
mud for skin care
new land
how to predict volcanic eruptions
tiny earthquakes
rising magma detected under earthquakes
escaping gas
increased mama temperature
changes in tilt of volcanoe
seismic waves
when there is too much pressure, their stored strain energy is released in waves (vibrations that earthquakes give out)
richer scale
the measurement of earths magnitude
focus
where earthquakes start beneath the earths surface
epicenter
point directly above the focus
how to manage the earthquakes
rubber shock absorbers - keep building from falling
cross bracing - stronger buildings
controlled counter weight - moves buildings to opposite sides of the earthquakes
