Layers Of the Earth 1.Mantle 2. Lithosphere 3. Outer Core 4. Inner Core

How compressional forces are caused. Compressional / Destructive (subduction zones) plate boundaries occur when an oceanic plate is forced under (or subducts) a continental plate Compressional / Destructive (subduction zones) plate boundaries occur when an oceanic plate is forced under (or subducts) a continental plate What do you think could be the result of this type of force? What do you think could be the result of this type of force?

Compression at Work:

Earth Quakes

Relate selected plate movements to compressional and tensional forces An earthquake is a sudden movement of the earth's surface. An earthquake is a sudden movement of the earth's surface.earthquake Earthquakes are caused by the movement of the earth's tectonic plates. Earthquakes are caused by the movement of the earth's tectonic plates. –Earthquakes occur where the earth's plates meet along plate boundaries

An example of the cause of an Earthquake –For example as two plates move towards each other, one can be pushed down under the other one into the mantle. –If this plate gets stuck it causes a lot of pressure on surrounding rocks. – When this pressure is released it produces shock waves. These are called seismic waves. This is an earthquake. –The waves spread out from the point where the earthquake started - the focus. More damage is done near the focus. –The point on the earth's surface directly above the focus is the epicentre.

How tensional forces are caused Tensional / Constructive (divergent ) plate boundaries occur when two plates move away from each other Tensional / Constructive (divergent ) plate boundaries occur when two plates move away from each other What do you think could be the result of this type of force? What do you think could be the result of this type of force?

Volcanoes A volcano is a conical hill or mountain formed by material from the mantle being forced through an opening or vent in the Earth's crust. Volcanoes are found in three states - extinct, dormant and active. A volcano is a conical hill or mountain formed by material from the mantle being forced through an opening or vent in the Earth's crust. Volcanoes are found in three states - extinct, dormant and active.volcano –An extinct volcano will never erupt again. –A dormant volcano has not erupted in 2000 years. –An active volcano has erupted recently and is likely to erupt again. Volcanoes are found along destructive (subducting) plate boundaries, constructive (divergent) plate boundaries and at hot spots in the earth's surface. Volcanoes are found along destructive (subducting) plate boundaries, constructive (divergent) plate boundaries and at hot spots in the earth's surface.

What are the three main volcanoes? There are three main types of volcano - composite or strato, shield and Ash and Cinder. There are three main types of volcano - composite or strato, shield and Ash and Cinder. –Composite volcanoes, sometimes known as strato volcanoes, are between the steep sided ash and cinder cones and the low- lying shield cones. –They are formed from layers of ash and [lava] flows. When composite volcanoes erupt they are sometimes explosive and sometimes less violent. [lava] –Shield Shield volcanoes have gently sloping sides and are formed from layers of lava. Eruptions are typically non-explosive. Shield volcanoes produce fast flowing fluid [lava] that can flow for many miles. –Shield Shield volcanoes have gently sloping sides and are formed from layers of lava. Eruptions are typically non-explosive. Shield volcanoes produce fast flowing fluid [lava] that can flow for many miles. [lava] –Ash and Cinder volcanoes are typically violent and destructive, characterized by narrow tall cones.