Attempting AS geography PPQ..Watch
Hi, currently studying for my AS Geography exam in a couple of weeks.. found some questions to try and get me started. Would like some help to see if I'm going in the right direction with answers...
Outline the characteristics of the Earth's structure.
Describe the types of plates found in the Lithosphere.
Describe the mechanisms of plate movement.
Describe and explain the processes that occur at plate margins.
A convergent margin occurs where plates are moving towards eachother. There are two types of convergent margins – continental and oceanic / continental and continental, and they both behave differently. Where continental and oceanic crust meet, the denser oceanic crust is subducted [forming a subduction zone and oceanic trench]. As it is subducted, the oceanic crust is melted by the high heat and pressure due to friction. This friction and melting allows earthquakes and volancoes to be formed. Other landforms include oceanic trenches, island arcs, and fold mountains. The South American and Nazca plate are an example of a convergent margin and form the Andes. Continental and Continental crust are known as collision margins. Both crust are the same density and thickness so resist subduction and are instead forced upwards to create fold mountains such as the Himalyas. The forces of collision may also cause shallow focus earthquakes. A conservative plate boundary occurs when plates are moving in the same or opposite direction. Friction is occurs but is overcome in a stick-slip motion which is the cause for earthquakes. Crust is neither created nor destroyed so landforms are therefore not created. An example is the Sand Andreas fault, a margin between the Pacific and North American plate.