Chapter 25 Flashcards
When Hess discovered the system of mountain ranges on the seafloor what did he name it?????????
Hess discovered a system of mountain ranges on the seafloor separated by valleys, which is when he made the name mid-ocean ridge.
What Is a rift-valley?????
A long, narrow depression between peaks along the mid-ocean ridge
What is the boundary when two plates collide called???????
Convergent Plate Boundary.
How is subduction described
Thin, dense, and a form of magma.It also can transfer heat and fluids through a oceanic plate which then goes through a mantel.
Who came up with the Continental Drift hypothesis?
Alfred Wegener
What were some pieces of evidence that supported his hypothesis?
- The coastlines matched up like puzzle pieces.
- Large land animals fossils.
- Similar rock types and rock age.
What was the name of the super content?
Pangaea
Who came up with the seafloor hypothesis?
Harry Hess
How did he come up with the seafloor hypothesis? What did he use?
Sonar
Who discovered the mid-ocean ridge?
Harry Hess
Where can we find the younger rock on the seafloor? Is it further from the MOR or closer?
Closer to the MOR
What are the three types of boundaries?
- Divergent Boundary
- Convergent Boundary
- Transform Boundary
What are the two types of crust?
- Oceanic Crust
2. Continental Crust
How do convergent plate boundaries move?
They collided together
What types land forms can form when oceanic crust and continental crust collide
- Volcano
2. Deep sea trenches
Subduction only happens
yuh
What type of land forms can be created when two oceanic form together?
- Deep sea trenches
2. Hotspots
What type of land forms can be created when two continental crust come together?
Mountains
What type crust must be present for volcanic activity to occur?
oceanic crust
How do divergent plates move????
Outwards/Divide
What are specific examples of a divergent plate?????
- MOR (Mid-Ocean Ridge) Both are oceanic crust.
2. East African Rift ( Both Continental)
How do Transform Plates move???????
They slide horizontally past each other
What is a specific example of a Transform Plate???
San Andreas Fault
How do convection currents work????
- Magma heats up, becomes less dense, and rises.
2. Magma cools, becomes denser, and then sinks.
