"The internal structure of Earth is the solid portion of the Earth, excluding its atmosphere and hydrosphere."
The different layers of the Earth's interior and their physical properties.
Seismic waves: Seismic waves are the vibrations generated by earthquakes that travel through the Earth's interior and can be recorded on the surface.
Earthquakes: Earthquakes are the primary source of seismic waves and provide valuable information about the interior structure of the Earth.
Earth's layers: The Earth's interior is composed of several layers, including the crust, mantle, and core, each with unique physical and chemical properties.
Crustal structure: The Earth's crust is the thin outermost layer of the Earth and is composed of solid rock.
Mantle structure: The mantle lies beneath the crust and is the largest layer of the Earth's interior. It is characterized by high temperatures and pressures.
Core structure: The Earth's core is divided into two parts, an outer liquid layer and an inner solid layer, and is primarily made up of iron and nickel.
Seismic tomography: Seismic tomography is a technique used to create three-dimensional images of the Earth's interior based on seismic wave data.
P-waves and S-waves: P-waves are the fastest seismic waves and can travel through solids, liquids, and gases, while S-waves are slower and can only travel through solids.
Reflection and refraction: Seismic waves can be reflected or refracted at boundaries between different layers of the Earth, providing insight into the structure of these layers.
Mohorovičić discontinuity: The Mohorovičić discontinuity, or Moho, is the boundary between the Earth's crust and mantle and is defined by a change in seismic wave velocities.
Gutenberg discontinuity: The Gutenberg discontinuity separates the mantle from the core and is defined by a sudden drop in seismic wave velocities.
D" layer: The D" layer is located at the core-mantle boundary and is characterized by anomalous seismic wave velocities.
Hotspots: Hotspots are regions of high volcanic activity that are thought to be caused by hot plumes of material rising from the mantle.
Plate tectonics: Plate tectonics is the theory that describes the movements and interactions of the Earth's crustal plates, driven by convection currents in the mantle.
Inner core: The innermost layer of Earth's interior is the solid, dense, and extremely hot inner core. It is believed to be composed primarily of iron and nickel.
Outer core: The outer core surrounds the inner core and is a liquid layer composed mostly of iron and nickel. It is responsible for generating Earth's magnetic field.
Mantle: The mantle is the largest layer of Earth's interior and is composed of rocky material. It is divided into upper and lower sections and is responsible for processes like plate tectonics and the formation of volcanoes.
Lithosphere: The lithosphere is the rigid outermost layer of Earth, composed of the crust and the uppermost part of the mantle. It is broken up into several large tectonic plates that move and interact with one another.
Asthenosphere: The asthenosphere is a soft and plastic region of the upper mantle that lies below the lithosphere. It is responsible for the movement of the tectonic plates.
Moho: The Moho is also known as the Mohorovicic discontinuity and is the boundary between the Earth's crust and mantle. It is named after the seismologist who first discovered it.
Gutenberg discontinuity: The Gutenberg discontinuity is the boundary between the Earth's outer and inner core. It is named after the seismologist who discovered it and marks a significant increase in density and seismic wave velocity.
Lehmann discontinuity: The Lehmann discontinuity is a boundary within the Earth's inner core that separates it into two layers with different physical properties. It was discovered by Danish seismologist Inge Lehmann in 1936.
Bullen discontinuity: The Bullen discontinuity is a boundary within the Earth's lower mantle that is marked by an abrupt change in seismic wave velocities. It is named after Australian seismologist Harold Jeffreys Bullen.
"The structure consists of an outer silicate solid crust, a highly viscous asthenosphere and solid mantle, a liquid outer core whose flow generates the Earth's magnetic field, and a solid inner core."
"Scientific understanding of the internal structure of Earth is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanoes or volcanic activity, analysis of the seismic waves that pass through Earth, measurements of the gravitational and magnetic fields of Earth, and experiments with crystalline solids at pressures and temperatures characteristic of Earth's deep interior."
"The structure consists of an outer silicate solid crust..."
"...a highly viscous asthenosphere and solid mantle..."
"...a liquid outer core whose flow generates the Earth's magnetic field..."
"...a solid inner core."
"Scientific understanding of the internal structure of Earth is based on observations of topography and bathymetry..."
"Scientific understanding of the internal structure of Earth is based on observations of rock in outcrop..."
"...samples brought to the surface from greater depths by volcanoes or volcanic activity..."
"Analysis of the seismic waves that pass through Earth..."
"...measurements of the gravitational and magnetic fields of Earth..."
"...experiments with crystalline solids at pressures and temperatures characteristic of Earth's deep interior."
"...a liquid outer core whose flow generates the Earth's magnetic field..."
"The structure consists of an outer silicate solid crust..."
"...a highly viscous asthenosphere..."
"...a highly viscous asthenosphere and solid mantle..."
"...a liquid outer core whose flow generates the Earth's magnetic field..."
"...a solid inner core."
"...experiments with crystalline solids at pressures and temperatures characteristic of Earth's deep interior."