Plate Tectonics

By G7B Group 4

plate Tectonics

definition :

The lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates.

Structure of The Earth

DESCRIPTION

Inner core

Outer core

Mantle

Crust

he inner core is a hot, dense ball of (mostly) iron. It has a radius of about 1,220 kilometers (758 miles). Temperature in the inner core is about 5,200° Celsius (9,392° Fahrenheit). The pressure is nearly 3.6 million atmosphere (atm). The temperature of the inner core is far above the melting point of iron.

Earth's outer core is a fluid layer about 2,260 km (1,400 mi) thick, composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle

The mantle is the mostly-solid bulk of Earth's interior. The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust. The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up a whopping 84% of Earth's total volume.

Crust” describes the outermost shell of a terrestrial planet. Earth's crust is generally divided into older, thicker continental crust and younger, denser oceanic crust. The dynamic geology of Earth's crust is informed by plate tectonics

How fold mountains occur near the boundaries of tectonic plates.


Fold mountains are created where two or more of Earth's tectonic plates are pushed together. At these colliding, compressing boundaries, rocks and debris are warped and folded into rocky outcrops, hills, mountains, and entire mountain ranges. Fold mountains are created through a process called orogeny.

How earthquakes occur near the boundaries of tectonic plates.


Earthquakes occur along fault lines, cracks in Earth's crust where tectonic plates meet. They occur where plates are subducting, spreading, slipping, or colliding. As the plates grind together, they get stuck and pressure builds up. Finally, the pressure between the plates is so great that they break loose.

How volcanoes occur near the boundaries of tectonic plates.


At constructive plate boundaries, the tectonic plates are moving away from one another. The Earth's crust is pulled apart to create a new pathway for rising hot magma to flow on to the surface. Volcanoes can sometimes form in these setting; one example is Iceland.