Layers of the Earth
This thin, outermost solid layer of the Earth is where all landforms, oceans, and life exist.
Crust
The asthenosphere is part of this main layer of Earth's interior.
Mantle
These two heavy metals make up the vast majority of Earth's core.
Iron and Nickel
Most of what scientists know about the internal structure of the Earth comes from studying these waves generated by earthquakes.
Seismic Waves
Continental crust is primarily composed of this lighter, less dense igneous rock.
Granite
Making up about 84% of Earth's total volume, this thick, semi-fluid layer lies between the crust and the core
Mantle
Tectonic plates "float" and move on top of this partially molten, ductile layer of the upper mantle.
Asthenosphere
The two most abundant elements in Earth's crust by weight are silicon and this gas.
Oxygen
A scientific instrument used to detect, measure, and record ground motions and seismic waves caused by earthquakes, volcanic eruptions, or explosions.
Seismograph
Oceanic crust typically exists at a depth range of 5 to 10 kilometers, while total crust depth ranges up to this maximum thickness.
70 Kilometers
This layer is unique because it is the only fully liquid layer of Earth's interior, composed mostly of iron and nickel.
Outer Core
What are the layers of the Mantle
Upper Mantle and Lower Mantle
What is the Earth's shape?
Oblate Spheroid
These fast seismic waves can travel through both solid rocks and liquid layers inside the Earth.
P-waves
Of the two types of crust, this one is older and thicker, forming Earth's landmasses.
Continental Crust
Despite extreme temperatures that should melt metal, intense pressures keep this innermost layer in a solid state.
Inner Core
The Earth's mantle is primarily composed of silicate rocks rich in iron and this metal.
Magnesium
Oceanic crust is mainly made of dark, dense volcanic rock known by this name.
Basalt
Named after a Croatian seismologist, this boundary separates Earth's crust from the underlying mantle.
Moho or Mohorovičić Discontinuity
Of the two types of crust, this one is significantly thinner and denser.
Oceanic Crust
This rigid outer shell includes both the entire crust and the uppermost solid portion of the mantle.
Lithosphere
This lower portion of the mantle extends from a depth of about 660 km down to the boundary with the outer core.
Mesosphere
What is Peridotite
It forms the main part of Earth's upper mantle.
These seismic waves cannot travel through liquids, providing proof that the outer core is liquid.
S-waves
The boundary between the bottom of the lower mantle and the top of the outer core lies at this approximate depth in kilometers.
2,900 kilometers