Ch 2 - Modern Earth Science - Vocabulary

Front 1

true shape of earth; slightly flattened sphere, due to earth's rotation

Back 1

oblate spheroid

Front 2

imaginary striaght line which runs through the earth from the North Pole to the South Pole

Back 2

Axis

Front 3

all the earths water

Back 3

hydrosphere

Front 4

percentage of earth's water which is salty

Back 4

97%

Front 5

layer of gases surrounding the earth

Back 5

atmosphere

Front 6

what are the two most abundant gases in atmosphere and their percentages?

Back 6

78% nitrogen and 21% oxygen

Front 7

thin, sold outermost zone of the earth; makes up 1% of earth's mass

Back 7

crust

Front 8

crust underlying world's oceans; thin, only 5-10 km thick

Back 8

oceanic

Front 9

crust underlying earth's continetns. vaires 32 -70 km in thickness-thickest under mountains

Back 9

continental

Front 10

zone of rock nearly 2870 km thick which lies below the earth's outermost layer; divided into upper and lower regions, this zone makes up 2/3 of the earth's mass

Back 10

mantle

Front 11

this is the uppermost portion of the mantle, and TOGETHER WITH THE CRUST ON TOP OF IT - forms a rigid layer which is 65 - 100 km thick

Back 11

lithosphere

Front 12

below core this is about 200 km thick. It is sold rock, but because of enormous heat and prssure, this layer flows like putty

Back 12

asthenosphere

Front 13

The term which describes the ability of a solid to flow

Back 13

plasticity

Front 14

Forms the center of the earth, divided into inner and outer sections - made mostly of iron, this layer makes up 1/2 of the earth's mass

Back 14

core

Front 15

Dense layer of liquid iron about 2,190 km thick

Back 15

outer core

Front 16

Dense sold about 2,680 km diameter at the very center of the earth - mostly iron

Back 16

inner core

Front 17

Vibrations which originate at or near earth's surface due to earthquake or explosion and move through the earth

Back 17

seismic waves

Front 18

faster of two seismic wave types; they can move through solid, liquid or gas

Back 18

P waves

Front 19

Slower of two seismic waves types; they can only move through solid materials

Back 19

S waves

Front 20

Seismic waves travel ? through material which is more dense/rigid

Back 20

faster

Front 21

Short for Mohorovocic Discontinuity, this is the boudary between the crust and the mantle. Discovered because seismic waves speed up as they leave the less dense crust and enter the more dense mantle.

Back 21

Moho

Front 22

Locations on the earth more than 103 degrees from earthquake/explosion causing seismic waves where no secondary waves are felt, due to the fact that they cannot get through the liquid outer core of the earth.

Back 22

S wave shadow zone

Front 23

Locations on the earth more than 103 degrees but less than 143 degrees from earthquake/explosion causing seismic waves where no secondary waves are felt, due to the fact that they cannot get through the liquid outer core of the earth.

Back 23

P wave shadow zone

Front 24

Region of space (shich extends out past the atmosphere) affected by the earth's magnetic field

Back 24

magnetosphere

Front 25

Motions within this layer of the arth are thougth to be responsible for the creation of earth's magnetic field

Back 25

liquid iron outer core

Front 26

Force of attraction which exists between all matter in the universe- the most imporant things you will learn about all year. Its the law!

Back 26

gravity

Front 27

the amount of matter in an object

Back 27

mass

Front 28

the amount of gravity force exerted on a mass

Back 28

weight

Front 29

The amount of gravitiational attraction between two objects depends upon: 1) the MASSES of the two objects and 2) the DISTANCE between the two objects

Back 29

Law of Gravitation