chapter 25 Flashcards
A system of mountain ranges on the sea floor separated by valleys.
mid-ocean ridge
Long narrow depression that forms between peaks along the mid-ocean range.
rift valley
The boundary where two plates collide.
convergent plate boundary
When a thick and buoyant continental plate meets a thin and dense oceanic plate, the denser plate dives beneath the continent.
subduction
The boundary between two plates that are moving apart.
divergent plate boundary
A boundary where plates slide horizontally past each other in opposite directions.
transform plate boundary
A sudden movement or vibrations of the ground that occurs when rocks slip and slide along enormous cracks in Earths crust faults.
earthquake
A crack in Earths crust along which rock has moved.
fault
A sudden release of strain as rock moves along a fault.
elastic rebound
The point of origin for an earthquake.
focus
The point on earths surface directly above the focus.
epicenter
who came up with the continental drift hypothesis.
Alfred Wegener
what were some pieces of evidence that supported Wegeners hypothesis.
- large land animal fossils
- coast lines fit together like puzzles
- mountain ranges matched up with the same rock types
what was the name of the super continent.
Pangaea
who came up with the seafloor spreading hypothesis.
Harry Hess
How did Harry Hess discover seafloor spreading.
He used sonar which emitted waves that bounced off the seafloor
what did Hess discover using the sonar.
mid-ocean range
what are the types of plate boundaries.
- convergent plate boundary
- divergent plate boundary
- transform plate boundary
how do convergent plate boundaries move.
They move into each other, come together