Earth Science Vocab Ch. 2

Front 1

axis

Back 1

imaginary straight line running through the earth from North to South poles

Front 2

seismic waves

Back 2

vibrations that ravel through the earth

Front 3

crust

Back 3

the thin, soid, outtermost zone or the earths outter covering(1% of earths mass and 2 types)

Front 4

mantle

Back 4

below he crust, zone of rock nearly 2, 870 km thick (2/3 of the earths mass

Front 5

core

Back 5

below the mantle, forms the center of the of the earth, mostly iron

Front 6

moho

Back 6

boundary between the crust and the mantle

Front 7

shadow zones

Back 7

locations on theearths surfcae where neither s or p waves are detected or only p waves are

Front 8

magnetosphere

Back 8

rgion of space, which is affected by the earths manetic field

Front 9

gravity

Back 9

the force of attraction that exists between all matter in the universe

Front 10

law of gravitation

Back 10

states that the force of attraction between any two objects depends on the mass of the2 objects and howand the closer theyare, the greater will be the force of gravity between them

Front 11

rotation

Back 11

the spinning motion

Front 12

revolution

Back 12

the movement of the earth around the sun

Front 13

perihelion

Back 13

the earths closest point to the sun

Front 14

aphelion

Back 14

the earths farthest point from the sun

Front 15

summer solstice

Back 15

the day the suns rays strike earth at a 90 degree angle along the tropic of cancer

Front 16

winter solstice

Back 16

when the suns raysstrike the earth at 90 degrees and the tropic of capricorn, marks the beginning of winter in the northern hemisphere

Front 17

autumnal equinox

Back 17

when the suns rays strike earth at 90 degrees along with the equator marks the beginning of the fall in the northern hemisphere

Front 18

vernal equinox

Back 18

on march21 or 22 when the suns rays again strike earth at 90 degrees along the equator marks the beginning of spring in the northern hemisphere

Front 19

precession

Back 19

circular motion of the earths axis

Front 20

standard time zones

Back 20

to avoid problems caused by different local times, the earths surface is divided into 24 time zones

Front 21

international date line

Back 21

line running from north tosouth through the pacific ocean when is 8:00 am

Front 22

daylight saving time

Back 22

clocks are set one hr ahead of standard time in april

Front 23

satellite

Back 23

any object in orbit around another body with a larger mass

Front 24

geosynchronous orbit

Back 24

at an altitude of 36, 100 km a satellite completes a full revoution in 24 hrs

Front 25

polar orbit

Back 25

carries the satellite over the earths north and souhs poles