Lesson 1 - Topography Flashcards
What is the top layer of the earths structure called?
Lithosphere
What does the top layer contain? (2)
Crust, brittle upper mantle
What is the second layer of the structure called?
Asthenosphere
What does second layer contain? (1)
Mantle
What is a continental margin?
The region of transition from the continental to oceanic crust.
What is the difference between an active and passive margin?
Active margins are also tectonic plate boundary. A passive is when the transition is not associated with a plate boundary.
What is the continental shelf?
A shallow,flooded area of the continent.
What are features of the con. shelf? (2)
Flat, biologically rich as nutrients are prevented from sinking.
What caused the topography of the shelf? (2)
It is flat due to changes in sea level throughout history and movement of sediment
What is the shelf break?
The point at which the angle of the seafloor begins to deepen.
What angle is the shelf break?
4 degrees
What is the continental rise?
Where the continental crust begins to meet the oceanic crust.
Features of the continental rise (2)
Thick layer of accumulated sediment. Slope decreases and begins to level off.
What is the abyssal plain?
The deep ocean floor and the flattest region of earth due to the massive sediment buildup.
What features can be found on the abyssal plain? (3)
Hills, trenches and seamounts
What is a Guyot
A large seamount, which are active/extinct volcanoes.
What is a mid ocean ridge?
A continuous mountain range which occurs on divergent plate boundaries.
What is the MOR made of?
Basalt
Features of the MOR? (3)
Geologically active meaning faults, shallow earthquakes and volcanic activity.
