Earth’s interior & Plate Tectonics

Question 1

Alfred Wegner Discoveries

Answer 1

1924
Coastlines match
Rock type match
Appalachian mts
Glacial striations
Matching fossils

Question 2

Alfred Wegner failure

Answer 2

Non-scientific/scholarly
German language barrier
German social barrier
Evidence on ocean floor

Question 3

Henry Hess Discovery

Answer 3

1940s
Pacific Ocean floor has linear volcano chains (erosion/aging)
Deep trenches parallel to mts. & volcanos

Question 4

1960s

Answer 4

Mid ocean ridge discovered

Question 5

Marie Tharp & Bruce Heezen

Answer 5

Created physiographic map of ocean floor

Question 6

Vine & DH Matthew

Answer 6

Plates diverge from separating center
Earth’s magnetic field reverses

Question 7

Tectonic boundary 1

Answer 7

Divergent
<—>

Question 8

Tectonic Boundary 2

Answer 8

Convergent OC><OC

OC will bend under OC

Question 9

Tectonic Boundary 3

Answer 9

Convergent OC><CC

OC will bend under CC

Question 10

Tectonic Boundary 4

Answer 10

Convergent CC><CC

CC crust will crumple against CC
Creates mts

Question 11

Tectonic Boundary 5

Answer 11

Transform = parallel to another plate

Just sliding by

Question 12

Continental Crust

Answer 12

35-45 km thick
Silicate rock material
Rock types: igneous, sedimentary, and metamorphic
Low density

Question 13

Oceanic Crust

Answer 13

5-10 km thick
Young 0-320 million
Basaltic igneous rock & marine sediment
Denser than continental crust

Question 14

Mantle

Answer 14

2900 km thick
Largest part of earth by volume
Solid, untra-mafic dense rock called peridotite
Main mineral - Bridgmanite
Upper/lower mantle split at 660 km deep
Behaves like plastic
Temp: 1000-3700 C

Question 15

Geothermal Gradient

Answer 15

Temperature increases with depth

Question 16

Outer core

Answer 16

2255 km thick
Liquid iron / nickel
Very dense
Temp: 3000-4500 C
Generates the magnetic field

Question 17

Inner Core

Answer 17

Iron / nickel / mystery 3rd thing (oxygen or sulfur maybe)
Solid metal ball
1220 km radius
Temp: 5000 C

Question 18

Seismic Waves

Answer 18

Caused by earthquakes/bombs
Travels through denser material faster
S-waves can’t travel through liquid
Creates shadow zones

Question 19

Shadow zones

Answer 19

S-waves can’t travel through the outer core, so it leaves a ‘shadow’ opposite of the origin pt that is unaffected

Question 20

Geodynamo

Answer 20

Self sustaining cycle caused by the magnetic fields that give no rise to more electric currents

Question 21

Volcanos

Answer 21

Plates move in one direction over hot spots creating island chains. As the plate passes the hot spot the islands begin to erode

Question 22

Rate of tectonic movements

Answer 22

1-20 cm a year

Question 23

Magnetic field

Answer 23

Protects us from solar wind and radiation
Formed in the outer core

Question 24

Auroras / Northern lights

Answer 24

Caused by electrically charged particles in solar wind hitting the electromagnetic field

Different colors caused by different gases hitting the atmosphere

Question 25

Paleozoic Orogenic Belt

Answer 25

Appalachian mts British Isles Caledonia

Question 26

When did the coast of Spain form

Answer 26

Jurassic period

Question 27

Pyrenees Mountains

Answer 27

Formed during the Cretaceous period

Question 28

Paleozoic era

Answer 28

Pangea 570-245 mya Paleozoic orogenic belt

Question 29

Mesozoic Era

Answer 29

Jurassic period First Atlantic break 208-144 mya Cretaceous period Spain coast formed Pyrenees mts formed Southern Atlantic formed 144-66 mya