Ch 25 Flashcards
(39 cards)
Mid-Ocean Ridge
Hess discovered a system of mountains ranges on the seafloor separated by valleys
Rift Valley
A long, narrow depression
Convergent Plate Boundary
The boundary where two plates collide
Subduction
When a denser plate dives beneath a less dense plate
Divergent Plate Boundary
Two plates move along a mid-ocean ridge.
Two moving plates apart
Transform Plate Boundary
Plates slide horizontally past each other in the opposite direction
Earthquake
when tectonic plates move in the Earths crust
Fault
responsibility for an accident or misfortune
Elastic Rebound
what happens to the crustal material on either side of a fault during an earthquake
Focus
the center of interest or activity
Epicenter
the point on the Earth’s surface directly above a hypocenter or focus
Who came up with the Continental Drift hypothesis.
Alfred Wegener
what were some evidence that Wegener used to support his hypothesis
- Fossils(Large Land Animals Fossils)
- Coast Line( matched up like puzzle pieces)
- Mountain Ranges( matched up with same rock type and ages)
What was the name of the Super Continent
Pangia
Who came up with the Sea Floor Hypothesis
Harry Hess
How did he discover Seafloor Spreading Hypothesis
Sonar
What are the three types of plate boundaries
Divergent boundary, Convergent boundary, Transform boundary
subduction zones only happen with what type that boundaries
convergent plate boundaries
How do Divergent Plate Boundary’s move?
They divide( They move apart)
What are some examples of Divergent Plate Boundarys
- Mid Ocean Ridge(Oceanic Crust)
2. East African Rift( 2 Continental Crust)
How do Transform Plate boundary’s move
Slide past each other
what is a example of a transform Boundary
San Andres Fault ( Continental Crust )
What is a Convection Current
- Magma heats up, becomes less dense and rises
2. Magma cools down and gets dense, then sinks down
What plate boundary has shallow earthquakes
Divergent and Transform