Science 10 Chapter 12

Front 1

asthenosphere

Back 1

Partly molten layer in Earth's upper mantle just below the below the lithosphere.

Front 2

continental drift theory

Back 2

Theory that the continents weren't always where they are today but that they moved over millions of years.

Front 3

converging plates

Back 3

Tectonic plates that are colliding.

Front 4

diverging plates

Back 4

Tectonic plates that are spreading apart.

Front 5

earthquakes

Back 5

Sudden ground shaking releases of built up

energy at or under Earth's surface.

Front 6

epicenter

Back 6

Point on Earth's surface directly above the focus where an earthquake starts.

Front 7

fault

Back 7

A large break in rock layers.

Front 8

hot spot

Back 8

Area where molten rock rises to Earth's surface.

Front 9

inner core

Back 9

Earth's solid center.

Front 10

lithosphere

Back 10

Layer of Earth made up of the crust and upper most mantle and ranging in thickness from 65km to 100km.

Front 11

mantle

Back 11

Earth's thickest layer, lying just below the crust and making up 70% of Earth's volume.

Front 12

mantle convection

Back 12

Reacurring current in the mantle, happens when hotter, less dense material rises, cools and then sinks again. This current is believed to be one of driving forces behind tectonic plate movement.

Front 13

outer core

Back 13

Layer below Earth's mantle.

Front 14

paleoglaciation

Back 14

Extent of ancient glaciers, also the rock markings they left behind.

Front 15

plate tectonic theory

Back 15

Theory the lithosphere is broken up into large plates that move and rejoin: considered unifying theory of geology.

Front 16

primary waves

Back 16

Type of seismic body wave that travels at about 6km/s through Earth's crust, causing the ground to move in the direction of the waves motion.

Front 17

ridge push

Back 17

Process where new material at a ridge or riff pushes older material aside moving the tectonic plates away from the ridge.

Front 18

slab pull

Back 18

Pulling of a tectonic plate as it's edge subducts deep into the mantle.

Front 19

rift valley

Back 19

A steep sided valley formed on land when

magma rises to earth's surface at a spreading center.

Front 20

secondary waves

Back 20

Type of seismic body wave that travels at about 3.5km/s, causing the ground to move

perpendicular to the direction of waves motion; also known as a shear wave.

Front 21

spreading ridge

Back 21

Region where magma breaks through Earth's surface continually forcing apart old rock and forming new sea floor.

Front 22

subduction zone

Back 22

Area's of subduction, which typically experience large earthquakes and volcanic eruptions.

Front 23

surface waves

Back 23

Seismic waves that ripple along Earth's surface.

Front 24

tectonic plates

Back 24

Large slabs of rock that form Earth's surface, moving over a layer of partly molten rock.

Front 25

transform fault

Back 25

A fault that occurs at a transform plate

boundary.

Front 26

trench

Back 26

Deep underwater valley that is formed when an oceanic plate collides with a continental plate and is forced to slide beneath it.

Front 27

volcanic belt

Back 27

Long chain of volcanoes.

Front 28

volcanic island arc

Back 28

Long chain of volcanic islands

Front 29

volcanoes

Back 29

Openings in Earth's surface that when active spews out gases chunks of roc and melted rock.

Front 30

Evidence for continental drift

Back 30

Coasts of the continents can be aligned, similar rocks, fossils and patterns of paleoglaciation.

Front 31

Mesosaurus

Back 31

Fossil of a sharp toothed, freshwater reptile. South America, Southwestern Africa.

Front 32

Cynognathus and Lustrosaurus

Back 32

Fossils of 2 land dwelling animals. Southern hemisphere.

Front 33

Glossopteris

Back 33

Fern fossil. South America, Africa and Australia.

Front 34

The crust (composition/size)

Back 34

Solid, continental-granite, oceanic-basalt, 10-160km.

Front 35

The mantle (composition/size)

Back 35

Semi solid. 2900km. Upper: partly molten rock, iron, magnesium. Lower: iron, magnesium.

Front 36

Outer core (composition/size)

Back 36

Liquid, 2300km, iron, nickel.

Front 37

Inner core (composition/size)

Back 37

Iron, nickel, Solid.

Front 38

Cinder cone volcanoes

Back 38

Layers of broken rocks blown out of the crater. Steep cone. Smaller and easily eroded. Ex. Crater lake, Lava Butte.

Front 39

Shield volcanoes

Back 39

Layers of lava. Slopes gentle, gentle layers of basalt, large, formed over hot spots. Ex.

Hawaiian Islands

Front 40

Composite volcanoes (stratovolcano)

Back 40

Alternating layers of ash and lava. Steep slope, very large. Ex. Mt. St Helens, Mt. Hood, Mt. Rainier, Mt. Shasta, Mt. Adams