chapter 13 tectonics

Question 1

hot spot

Answer 1

a vocanically active region that is caused by a mantle plume

Question 2

mantle plume

Answer 2

a vertical column of hot rock that extends down as far as the earths outer core

Question 3

hot spot tracks

Answer 3

lines of inactive volcanoes in ocean basins

Question 4

fold

Answer 4

a wrinkle in the crust that results from deformation caused by geologic stress

Question 5

fault

Answer 5

a fracture or a break in the crust where movement and earthquakes occur

Question 6

block landform

Answer 6

fracture in crust where movement and earthquakes occur, usually near plate boundaries

Question 7

orogenesis

Answer 7

mountain building

Question 8

orogenic belt

Answer 8

a linear mountain range

Question 9

the ______ ______’s waters supply for 1.4 billion people, which could lose 70% of its glaciers by the _____ __ ___ _____.

Answer 9

tibetan plateau

end of the century

Question 10

pros of hydropower megaporjects

Answer 10

water and flood security
flood protection
hydroelectricity

Question 11

cons of hydropower megaprojects

Answer 11

unwanted environmental consequences
unwanted social consequences
international conflict
potential dam failure

Question 12

pangaea

Answer 12

supercontinent that formed 300 million years ago

Question 13

pangaea split into Laurasia and gondwana about _____

Answer 13

200 million years ago

Question 14

laurasia

Answer 14

eventually became north america, greenland and eurasia

Question 15

gondwana

Answer 15

eventually became south america, australia, africa, india and antarctica

Question 16

continental drift

Answer 16

theory proposed continents move slowly across earths surface

Question 17

plate tectonics

Answer 17

theory describing origin, movement, and recycling of lithospheric plates and the resulting landforms

Question 18

subduction

Answer 18

the process which oceanic lithosphere of one plate bends and dives into the mantle beneath another plate

Question 19

how many tectonic plates are there

Answer 19

7 primary and 7 secondary, the largest plate is the pacific plate

Question 20

active vs passive continental margin

Answer 20

active- consists of deep sea trench and narrow continental shelf
passive- broad, sloping continental shelf and does not coincide with plate boundary

Question 21

ridge push

Answer 21

process by which magma rising along a mid ocean ridge lifts oceanic lithosphere and forms a slope

Question 22

mantle drag

Answer 22

movement of a plate caused by friction between moving asthenosphere and the lithosphere

Question 23

slab pull

Answer 23

weight of a subtracting portion of a plate accelerates plate movement by pulling the plate deeper into the mantle

Question 24

divergent vs convergent vs transform plate boundaries

Answer 24

divergent- where two plates move apart
convergent- where two plates move towards each other
transform- where one plate slips laterally past another

Question 25

decompression melting

Answer 25

melting hot mantle through changes in pressure

Question 26

rift

Answer 26

region where continental crust is stretching and splitting

Question 27

rift valley

Answer 27

a long valley with volcanoes formed by rifting of continental crust

Question 28

oceanic lithosphere is consumed and recycles in process of _______

Answer 28

subduction

Question 29

continental lithosphere is not subducted because __________

Answer 29

it is less dense than oceanic lithosphere and too buoyant

Question 30

flux melting

Answer 30

the process in which the mantle mixes with seawater and melts into magma

Question 31

volcanic arc

Answer 31

a long chain of volcanoes on the margin of a continent where subduction is occurring

Question 32

continental arc

Answer 32

a long chains of volcanoes that forms only on the margins of a continent where subduction is occuring

Question 33

island arc

Answer 33

a chain of volcanic islands formed where oceanic lithosphere of one plate subducts beneath oceanic lithosphere of another plate

Question 34

collision

Answer 34

the process in which contiental rust of two plates converges

Question 35

accreted terrane

Answer 35

a mass of crust that is transported by plate movement and fused onto the margin of a continent