smallest volume of earth (3-25miles)

outermost layer

solid in state

isolated pockets of magma

thinnest part of crust

3 miles / avg of 5 miles

main composition- BASALT

Thickest part of crust

25 miles / avg 20

composition- GRANITE

 1800 miles

largest volume

solid in state

 upper portion has hot spots (plumes)

seismologist

1909

founded mojo discontinuity (boundary from crust to mantle)

Upper mantle -  2 parts;

upper- lithosphere

lower - astheosphere ( low velocity zone)

rigid rock

Outer- liquid (Fe-Kamacite)

source of earths magnetic field

Inner- (Fe- kamacite) solid

Astronomy

 2 parts

Moon & motions

Meteorites

Rocky meteorites- (silicates)

Metalic meteorites (iron and nickle)

break in rock mass when movement takes place

major cause of earthquakes

zone within earth where rock displacement takes place

85% shallow focus

12% intermediate focus

3% deep focus

Body

Surface

  causes expansion & contraction causes molecules to move back in forth in direction wave travels 

fastest

smallest amplitude on seismograph

travels through solid liquid and gas

molecules move perpendicular to which wave travels

slow

larger in amplitude

can only travel through a solid

Surface waves

travel on outer layer of earth

slowest

largest

causes damage

measures magnitude during earthquake

1.0- 9.0+

intensity amount

determined by damage & field observations, roman numerals

Book titled - Origins of continents in ocean

proposed idea of continental drift

200mill years ago supercontinent PANGIA

fossil clues

rock structure clues

climate clues

oldest rock on ocean floor- 180 million years

oldest rock on continental floor- 4 billion years

Brittish sonar technology used

created maps of ocean floors

under water mountain formed by a rift

mid atlantic ridge longest mnt range

under water trench formed from subduction

1960 explains seafloor spreading

explained ocean ridges/depressions

dug up rocks and dated them

youngest were close to ridges

oldest were close to continent

showed magnetic reversal

magnetameter- detects & records magnetic data

-lithosphere broken up in sections called plates

-plates move in relationship to each other on astenospher

-plates form boundries where plates come together

-action takes place at boundries

N AMERICA

S AMERICA

EURASIAN

AFRICAN

PACIFIC

INDO-AUSTRALIAN

ANTARTICA

tension

quite volcanic activity/ minor earthquake activity

2 ocean floor plates diverge - mid ocean ridge

2 continental plates diverge- rift valley

eurasian  & aftrican plate

separate from

n american & s american plate

compression

explosive volcanos & earthquakes

deep sea trench

ocean floor plate & continental plate - subduction (earthquakes and volcanos)

2 ocean plates- (volcanos, sea trenches)

puru chilie trench

Sheering

major earthquake/ no mountain formations

san andres fault, mt. st. helen

Hawaiian islands- hot spots (plumes)

FAULT BLOCK mts.

Tentons- wyomming

Sierra Nevada- eastern part california

Rocky mts. - no explenations

Appalachians

250-300 million years old

worn down, rounded, heavy vegitation

Youngest mountain

Rocky

60 million

taller

jagged summit

little vegitation

discordant- cuts through surrounding bedrock

concordant- same direction as surrounding bedrock

tabular- thin in thickness compared to length

nontabular- any other shape

dike- small size tabular

stock- large nontabular

batholith- very large nontabular

Stock & batholith form mountains

sill- small size, tabular

lacolith- mushroom shape non tabular

lapolith- upsidedown lacolith nontabular

Folds

horizontal/ lateral- produce earthquakes (sheering)

vertical- produce mountains and earthquakes (compression & tension)

normal-  increase surface area (compression)

reverse- shorten surface wall (tension)

600 active- fresh/low erosion

Dormant- fresh/little sign of erosion

Extinct

high % of trapped gas in magma

formed from water vapor and co2

granite magma

quite eruption

largest

basaltic lava

explosive eruptions

pyroclastic debri

 10-20 year lifespan