Page 34 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

17
eseydsoylyy *}
System
Lithosphere/Asthenosphere
Hard Solid
=
Earth
Temperature and Pressure with Depth)
(Physical State Due to Increasing
the
of
Divisions
Modern
to changes in to increasing Five zones of differing physical state relate Earth. Modern divisions of the 2.4 FIGURE oxygen), with densities the surface to from lithosphere is a hard solid, extending (P) with depth. I) The pressure and (T) temperature of Earth's volume, of its 1% with a uppermost mantle. II) The asthenosphere is solid includes the crust and km
zones of differing density correspond and in silica (silicon less is than 2% from Extending magnesium. It comprises 82% nickel. [t Earth at 6300 km. The differentiated Earth the concentrated toward in changes to 1960's the in spheres, A three according physical their to recognized thus and outer core, of date. out not is scheme and crust the

Earth minerals rich 70 km. It and iron in to 5.8 g/cm?. the center of the to century, material correspond core. seismographs better the within spheres zones Five (or mesosphere), classical the boundaries, between The modern conditions Silicates comprising the of part top also are mantle depths At melting, partial

Tectonics the of Classical divisions of the Earth. Three 1) The crust is mainly thickness between 2 and from 3.3 mass, 3) The core is predominately iron, with other heavy elements like from 2900 km of its mass. the 20th denser the density in and mantle and more velocities wave the three liquid). or lower mantle that 2.3). (Fig. under 2.4). the uppermost lithosp

Plate Divisions (Density Differentiation due to Changes in Chemical Composition) mass. 2) The mantle is silicate minerals rich of part density, to differences crust, of of seismic of portions solid, soft illustrates chemical core the chemicals (Fig. Earth forming rigid, the the of undergo

Chapter2 Classical 2.3 chemical composition, between 2 and 3 g/cm’ and depth, mantle density increases 10.8 g/cm? and extends Earth’s volume and 32% early the in according Drastic the defining Divisions The installation olution describes relatively asthenosphere, Fig. 2.5 along still are and mantle of state those the within they are silicates of remainder materials

16 FIGURE about Modern
*