Assignment 3 The Global Ocean (Chapters 13, 14 and 15) signment we are going to
ID: 290961 • Letter: A
Question
Assignment 3 The Global Ocean (Chapters 13, 14 and 15) signment we are going to look at the ocean including the ocean floor, nd life as well as the dynamics that makes it work. As is the case with ctions of Earth Sclence, Ocean Science plays a role in the dynamics of arth as a whole, and is tled very closely to our next topic, weather he Ocean Floor agram below to answer the following questions: g the figure above, select the letter that identifies each of the following of the continental margin: . Deep sea fan b. Submarine Canyon: d. Continental Shelf e. Continental Rise:Explanation / Answer
1. a) Deep sea fan : C
b) Submarine canyon : A
c) Continental Slope : F
d) Continental Shelf : B
e) Continental Rise : M
f) Shelf break : E
2. Abyssal plains or deep sea floor are present at the end of the continental rise at depths of around 3000 to 6000metres. They are usually elongate, irregular in outline, flat and vast, sediment-covered areas of the deep ocean floor and cover more than 50% of the earth's surface.
Abyssal plains are formed as a result of sea floor spreading along the mid oceanic ridges and the subsequent melting of the lower oceanic crust.
In the figure above, the letter D represents an Abyssal plain.
3. The Continental margins surrounding the Atlantic are Passive continental margins. The Continental margins surrounding the Pacific are active continental margins.
A passive continental margin is tectonically stable and inactive and it marks the transition between continental and oceanic lithosphere. Continental rifting along these passive margins gives rise to new ocean basins. Thus, they are constructive margins along which new materials are being created and so the Atlantic is getting larger.
On the other hand, the active continental margin surrounding the Pacific marks the subduction of one lithospheric plate beneath another resulting in volcanoes and earthquakes. It is tectonically very active. Thus it is a destructive margin where materials are being underthrusted and destroyed. So the Pacific is shrinking.