Chapter 25 Flashcards
a system of mountain ranges on the seafloor separated by valleys
mid-ocean ridge
long narrow depression that forms between peaks along the mid-ocean ridge
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 in a process called what?
subduction
the boundary between two plates that are moving apart
divergent plate boundary
this type of boundary where plates slide horizontally past each other in opposite directions
transform plate boundary
a sudden movement or vibration of the ground that occurs when rocks slip and slide along enormous cracks in Earth’s crust called faults
earthquakes
a crack in Earth’s crust along which rock has moved
fault
a sudden release of strain energy as rock moves along a fault
elastic rebound
the point of origin for an earthquake
focus
the point on Earth’s surface directly above the focus
epicenter
who came up with the continental drift hypothesis?
Alfred Wegener
what were some pieces of evidence that supported Wegener’s hypothesis?
- coastlines match up like puzzle pieces
- they found large animal fossils
- mountain ranges match up; rocks are made of same composition and age
what was the name of the super continent?
Pangaea
who came up with the seafloor spreading hypothesis?
Harry Hess
what did he use to map the bottom of the seafloor?
he used sonar
who discovered the mid-ocean ridge?
Harry Hess
where on the bottom of the seafloor is the youngest rock going to be found?
nearest to the MOR (mid-ocean ridge)
