Chapter 3 6Th Grade

Front 1

the study of the earth and its structure

Back 1

geology

Front 2

scientists who study the structure of the earth

Back 2

geologists

Front 3

the rocks of the crust are covered by a thin layer of soil and a thick layer of sand and mineral fragments called ____

Back 3

sediments

Front 4

the temperature of the rocks ______________ with depth

Back 4

increases

Front 5

the middle layer of the earth

Back 5

mantle

Front 6

the boundary between the crust and the mantle is called the

Back 6

moho

Front 7

beneath the mantle lies the ________, the intermost region of the earth

Back 7

core

Front 8

is essential for all plant life

Back 8

soil

Front 9

a process that causes rocks to gradually break or crumble into smaller pieces

Back 9

weathering

Front 10

occurs when natural acids slowly eat into a rock and break it apart

Back 10

chemical weathering

Front 11

takes place when rock is broken down by water, ice, or windblown sand

Back 11

physical weathering

Front 12

as different plates are dragged in different directions, they often collide or grind together at their edges

Back 12

plate collisions

Front 13

the earths oceans contain underwater mountain ranges called ___________where plates of the earths crust are moving away from each other

Back 13

mid-oceanic ridges

Front 14

the sudden movement of the pacific plate under the ocean floor also created monstrous waves known as ___________

Back 14

tsunamis

Front 15

any trembling or shaking of the earth's crust

Back 15

earthquake

Front 16

a weak earthquake

Back 16

tremor

Front 17

smaller earthquakes or tremors called ________ may occur periodically for days or even months after a major earthquake

Back 17

aftershocks

Front 18

the study of earthquakes

Back 18

seismology

Front 19

scientists who study earthquakes

Back 19

seismologists

Front 20

the rock bends without cracking, the result is called a

Back 20

fold

Front 21

the break that appears at the boundary between two moving masses of rock is called a

Back 21

fault

Front 22

the point under ground where an earthquake begins is called the

Back 22

focus

Front 23

the place at ground level that is directly above the focus

Back 23

epicenter

Front 24

seismologist devised scales of earthquake strength or _____

Back 24

magnitude

Front 25

the most famous scale used to measure earthquake strength is the

Back 25

richter scale

Front 26

since these faults produce most of the world's earthquakes, the regions where they are found are called

Back 26

seismic belts

Front 27

melted rock

Back 27

magma

Front 28

if a weak spot exists in the earth's crust, the magma may squeeze its way upward through the crust and form a large reservoir or ____

Back 28

magma chamber

Front 29

trapped gases blast an opening through the earth's surface called a

Back 29

vent

Front 30

a vent that allows molten rock and hot gases to escape from within the earth

Back 30

volcano

Front 31

after reaching the earth's surface, molten rock is called

Back 31

lava

Front 32

this belt of volcanoes is called a

Back 32

ring of fire

Front 33

vents or holes in the surface that gases escape through

Back 33

fumaroles

Front 34

when lava fragments solidify almost instantly into fragments of rock, this is called

Back 34

tephra