what is a convergent plate boundary
a convergent plate boundary is what happens when 2 plates move together
what is a divergent plate boundary
a plate boundary where 2 plates move apart from each other
who was alfred wegner
he came up with the idea of pangea
what is the ring of fire
an area in the pacific ocean where many earthquakes and volcanoes occur
what is the part all the way in the inside of the earth
core
what natural disasters are caused by convergent plate boundaries
volcanoes and earthquakes
what natural disasters do divergent plate boundaries
minor earthquakes
what is pangea
1 super continent with all the continents together
what percent of volcanoes occur in the ring of fire
75%
layer between the crust and the core
mantle
what are the 3 types of convergent plate boundaries
oceanic oceanic
continental continental
oceanic continental
what type of divergent plate boundary do mid ocean ridges form
oceanic oceanic
when was wegener's theory accepted
in the 1960's
what percent of volcanoes are located at the ring of fire
75%
what is the outer core
liquid layer of the Earth's core
what is one of the land forms are are made by convergent plate boundaries
Deep ocean trenches, volcanoes, island arcs,
what causes seafloor spreading to occur
heat from the mantle's convection currents
when did wegner die
1930
how big is the ring of fire
25,000 miles
what is the inner core
solid, dense center of the Earth
what happens at an oceanic oceanic plate boundary
the mantle is pushed, or subducted, under the other
In which two places do divergent boundaries occur?
Rio Grande Rift in Texas.
what did scientists say to dis prove alfred wegener's theory
people argued that wegener's theory did not explain the forces that would have been needed to move continents so far
how many volcanoes and earthquakes happen in the ring of fire
900
soft layer of the mantle
asthenosphere