Seismology and earth science
| This figure is similar to a frozen version of the animation in the lecture notes. It shows the tracks of the waves with the different zones labeled. The size of the S-wave shadow gives us directly the size of the liquid core. The size of the P-wave shadow and the nature of the P-waves refracted in the liquid core can tell us about the material in this region. The way the P-waves refract on the solid inner core let us study its size and composition, as discussed in detail below. see also http://phoenix.liu.edu/~divenere/notes/earth_int.htm |
From J. Louie, http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html Before five billion years ago, the Earth was formed by the tremendous collision and bombardment of meteorites and comets. The massive quantity of thermal energy emitted by the high-velocity bombardment melted the whole planet, which is still cooling now.
Denser meteorite components, such as iron (Fe), sunk into the Earth’s core, while lighter cometary silicates (Si), various oxygen (O) compounds, and water rose to the surface. (J. Louie) The earth has four major layers: the inner core, the outer core, the mantle, and the crust. The core consists mostly of iron (Fe) and is so hot that the outer core is liquid, with around 10% sulfur (S).
Under such tremendous pressure, the inner core stays solid. The mantle, comprised of iron (Fe), magnesium (Mg), aluminum (Al), silicon (Si), and oxygen (O) silicate compounds, contains the majority of the Earth’s mass. At temperatures above 1000 degrees Celsius, the mantle is solid but can slowly deform plastically.
What are the three primary interior zones?
3.1 The Layers of the Earth: Crust, Mantle, and Core The three major layers of the Earth are the crust, the mantle, and the core (Figure 3.4). The core comprises about half of the Earth’s radius, but only 16.1% of the planet’s volume. The mantle comprises the majority of the Earth’s volume (82,5%), whereas the crust comprises just a little portion (1.4%).
What are the five structural zones in the interior of the Earth?
We shall now investigate the five structural zones. The lithosphere, asthenosphere, mesosphere, inner core, and outer core comprise the structural zones (S-Zones) of the Earth. Scientists have detected seismic waves from earthquakes over the years. These waves have assisted scientists in learning more about our planet’s interior.
How do the primary internal zones of the Earth vary from one another?
Inner core, outer core, mantle, oceanic crust, and continental crust are the primary internal zones of the Earth, in sequence from the center to the surface. These zones differ in material composition, thickness, and density, which decrease from the center to the surface.
What are the sorts of the earth’s interior?
The interior of the planet consists of three distinct layers: crust, mantle, and core. The crust is the uppermost layer of the planet, whereas the core is the deepest layer at a depth of 2900 kilometers.
