Geography assignment.

My geo teacher gave the class an assignment about plate tectonics about a week ago so yeahh...he gave us one week to do four simple questions...and as usual i delayed. i started doing the work about five hours ago and it took me two hours to complete them and i knoww....you guys might be thinking 'what the hell! four questions two hours!' it turns out that, the questions weren't so simple...once i read them and fully understand it haha. i used the internet to answer most of the questions so thank you major figures such as Leonard Kleinrock, J.C.R Licklider, Larry G.Roberts, Bob Kahn, Vint Cerf and Radia Perlman for making internet a reality. i got nothing else to say so im just going to post my geo hw here. enjoy reading these boring facts but at the same time fill your mind with knowledge.

p.s i dont know if my answers are right, so you judge.

Name: Firdaus
Class: Geography block 1
Group: Be 4

Plate Tectonics.

1. 1.a) Define the terms continental plate and oceanic plate.

- Continental plate is a crustal material located within the continent, it is more buoyant and heavy making it very hard to subduct when colliding.

- Oceanic plate is also a crustal material located in the oceans, it is lesser in thickness and weight compared to continental plate which makes it easy to subduct when colliding.

b) Describe one landform that may develop at a convergent plate boundary.

- The nature of a convergent boundary depends on the type of lithosphere in the plates that are colliding. Where a dense oceanic plate collides with a less-dense continental plate, the oceanic plate is typically thrust underneath because of the greater buoyancy of the continental lithosphere, forming a subduction zone. At the surface, the topographic expression is commonly an oceanic trench on the ocean side and a mountain range on the continental side. An example of a continental-oceanic subduction zone is the area along the western coast of South America where the oceanic Nazca Plate is being subducted beneath the continental South American Plate.

22. With the aid of a diagram describe the principal features of a divergent plate boundary.

Divergent boundaries are areas in which plates move away from each other. The majority of these divergent boundaries are located along the crests of the mid-oceanic ridges, continental rift valley is the place where continent is pulling apart and sometimes continent will break-up entirely, an ocean basin will form. As the plates separate, fractures occur which are immediately filled with molten rock that up wells from the asthenosphere. This hot material cools and creates a new seafloor. As a result, new oceanic crust (lithosphere) is continuously being created between the diverging plates. The older crust moves away from the boundary, as it does so, it cools and contracts hence increasing in density and in thickness. This is why the older and cooler oceanic crusts are deeper. This average rate of spreading is about 5 cm per year.

1. How does an understanding of plate tectonics help to explain the development of earth’s crustal features?

- The understanding of plate tectonics will help to explain the development of earth’s crustal features, in plate tectonics we study about the movement of the earth’s crust, the movement is concentrated in narrow belts along ridges, deep sea trenches and major strip-like faults. These long linear features are not isolated, but are interconnected in a global network and represent the boundaries for 12 plates. When one type of feature is terminated it is transformed into a boundary of different type. There are three types of plate boundaries that can also explain the development of earth’s crustal features and they are divergent plate boundary, convergent plate boundary and transform boundaries. Each one will develop different types of features, for example in convergent plate boundaries, when ocean-continent collision occur ocean trenches will form along the margin of the continent, volcanic arc will take form along the margin of the continent , foreland fold and thrust belt are also likely to form. So by understanding plate tectonics along with its principal and how it works, we will be able to explain the development of earth’s crustal features.