13.3 Plate Boundaries

Question 1

How many tectonic plates are there

Answer 1

8 major plates but several smaller ones too

Question 1

tectonic plates

Answer 1

huge pieces of crust and rigid upper mantle that fit together at their edges to cover earth’s surface

Question 2

How much to tectonic plates move a year

Answer 2

few cm

Question 3

divergent boundaries

Answer 3

place where 2 of earth’s tectonic plates are moving apart
associated w volcanism, earthquakes, and high heat flow
magma comes to the surface creating new crust and they move apart

Question 4

where are divergent boundaries found

Answer 4

on the seafloor and at rift valleys

Question 5

rift valley

Answer 5

long, narrow depression that forms when continental crust begins to separate at a divergent boundary

Question 6

convergent boundary

Answer 6

place where 2 of earth’s tectonic plates are moving toward each other

Question 7

subduction

Answer 7

process by which one tectonic plate slips beneath another tectonic plate

Question 8

Oceanic crust is more __________ than continental crust

Answer 8

dense

Question 9

oceanic crust is composed of

Answer 9

minerals high in iron and megnesium

Question 10

continental crust is _____________ than oceanic crust

Answer 10

less dense

Question 11

continental crust is composed of what

Answer 11

minerals high in feldspar and silica

Question 12

When subduction occurs an oceanic plate will what

Answer 12

slip beneath the continental plate cuz its more dense

Question 13

how many types of convergent boundaries are there

Answer 13

3
oceanic-oceanic
oceanic-continental
continental-continental

Question 14

oceanic-oceanic

Answer 14

ocean trench created when an oceanic plate is subducted beneath another oceanic plate
the descending plate carries water with it
magma forms and rises
volcanic islands form

Question 15

oceanic-continental

Answer 15

an oceanic plate is subducted between a continental plate
descending plate carries water with it to the mantle
magma forms and volcanic mountains form

Question 16

continental-continental

Answer 16

2 continental plates collide into one another
form long after an oceanic plate has converged with a continental plate
many continental plates have oceanic crust attacthed to them
over time oceanic plate is completely subducted
the attacthes continental crust cannot subduct therefore the continents collide and uplift occurs
mountain ranges form

Question 17

transform boundary

Answer 17

region where 2 tectonic plates slide horizontally past each other
characterized by long faults and shallow earthquakes
faults can be 100s of km in length

Question 18

crust is only deformed at a __________________

Answer 18

transform boundary