The geologist who proposed the the theory of seafloor spreading
Who was Harry Hess?
100
A divergent plate margin devolping on a continent
What is a rift vally?
100
the process by which molten meterial adds new ocenaic crust to the ocean floor
What is Sea-Floor spreading?
100
what direction to divergent plates move?
they split apart
100
a place where new spreadimg center is developing on w continent and the continent is splitting apart today!
What is the East African Rift Zone
200
Who proposed the hypothesis of contental drift?
Alfred Wegener
200
Vally, volcanoes, streams, and rivers
What are land forms produced from rifts
200
sea floor spreading creates what in the ocean?
mid-ocean ridges
200
along spreding centers where plates are moving apart and new crust is created by magma pushing up form the mantle
Where do divergent boundaries occur?
200
proved the submerged ridges went down the middle of every ocean
Why waas the mapping of the ocean floor such qn improvement step in the development of plate tectonic theory?
300
alternating bands of magnet polarrity across the mid-ocean ridge
what did vine and matthews discover
300
a dropped zone where the plates are pulling apart
What is a rift
300
molten magma rising up to the surface
What causes sea-floor spreading?
300
the Mid-Atlantic ridge
What is the best known divergent boundary
300
true or false. is the earth's magnetic feild comstant
What is true
400
the geologist that first proposed that convection in the upper mantle is the force that drives plate movement
Who was Arthur Holmes
400
when two continental plates diverge
how are rifts created?
400
divergent boundaries
What kind of plate boundary runs across Iceland?
400
A place what tectonic plates move apart
What is a divergent plate boundary?
400
Eurasian and North American
Which plates seperated to from the Mid-Atlantic Ridge?
500
he was one of the first scientist to map the mid-ocean ridges
What did Robert Dietz do?
500
these form in and around the area where the newly formed valley like rifts develope as the two continental plates diverge.
What are valleys and volcanoes
500
On average how fasr does the sea floor spread?
as fast as your fingernail grows
500
divergent boundries are most like a _______ because they face eachother but slowly move in opposite directions as they transport newly formed oceanic crust away from the ridge
What is a conveyor belt
500
African and Arabian
What two plates pulled apart to create the Red Sea drift