Layers of the Earth and Earth Processes
iron and nickel
What is the core made of?
mountain range
a series of connected mountains
earthquake
a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.
destructive
causing great and irreparable harm or damage.
Compositional layers of Earth
crust, mantle, core
trench
extremely deep areas in the ocean that are created by a subducting plate
constructive
having a positive effect; helpful
subduction zone
in tectonic plates, the site at which an oceanic plate is sliding under a continental plate.
Inner Core
A dense sphere of solid iron and nickel at the center of Earth
Outer Core
A layer of molten iron and nickel that surrounds the inner core of Earth
Density
A measure of how much mass there is in a volume of a substance.
transform boundary
A plate boundary where two plates move past each other in opposite directions
Lithosphere
A rigid layer made up of the uppermost part of the mantle and the crust.
convergent boundary
A tectonic plate boundary where two plates collide, come together, or crash into each other.
Convection Currents
Circular currents in the upper mantle (mainly the Asthenosphere) caused by the magma being heated by the core off the Earth.
tectonic plates
Sections of the Earth's crust that move due to convection currents.
divergent boundary
The boundary between two tectonic plates that are moving away from each other
continental drift
The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
Mesosphere
The lowest part of the Mantle where the rock hardens into a solid.
Continental Crust
The portion of the earth's crust that primarily contains granite, is less dense than oceanic crust, and is 20-50 km thick
seafloor spreading
The process that creates new sea floor as plates move away from each other at the mid-ocean ridges
Asthenosphere
The solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it
Physical Layers of the Earth
lithosphere, asthenosphere, mesosphere, outer core, inner core
Oceanic Crust
the portion of Earth's crust that is usually below the oceans and not associated with continental areas, thinner and higher in density than continental crust and made up of basalt instead of granite.
Plate Tectonic Theory
the theory that the lithosphere is broken up into large plates that move and then rejoin; considered the unifying theory of geology
seismic waves
vibrations that travel through Earth carrying the energy released during an earthquake; scientists use these to study the layers of the Earth