Oceanography Chapter 3

Front 1

The theory of plate tectonics combines what two formally adversary theories

Back 1

Continental drift and seafloor spreading.

Front 2

the theory of plate tectonics suggests that the external surface of earth is composed of

Back 2

12 plate tectonics on which the continents rest.

Front 3

the plates float on the _______ layer. and cause geological events where?

Back 3

Asthenosphere; at the plate borders.

Front 4

The theory of Pangea is the theory that

Back 4

there was once a supercontinent called pangea and they broke up and moved to their current locations

Front 5

What evidence was used to produce the theory of continental drift?

Back 5

puzzle piece fit

occurance of fossils

occurance of geologic landmarks

Front 6

What is the theory of seafloor spreading?

Back 6

The idea that the continents are pushed apart as new sea floor is produced along a midocean ridge and pushes out the older sea floor.

Front 7

What is the source of energy for seafloor spreading?

Back 7

The convection in the mantle

Front 8

what evidence was used for the seafloor spreading theory?

Back 8

seafloor characteristics

Paleomagnetic pattern- change in magnetic field in aging rocks.

Radiochronometry

Geophysics- distribution of earthquakes and volcanoes.

Front 9

if ocean floor is being produced at the midocean ridges, where is sea floor being "destroyed"?

Back 9

deep ocean trenches.

Front 10

Plate tectonics are always moving. There are three types of boundaries that are classified by their movement next to eachother. What are the three?

Back 10

1.) Divergent boundaries
2.) Convergent boundaries
3.) shear boundaries

Front 11

What are the two kinds of crust and what rock do they produce?

Back 11

Continental Crust- granite (less dense, thicker)

Oceanic Crust- basalt (more dense, thinner, darker)

Front 12

2 examples of divergent boundaries

-continental/continental
-oceanic/oceanic

Back 12

East African Rift Zone

Mid ocean ridge

Front 13

3 examples of convergent boundaries

-continental/continental
-oceanic/oceanic
-continental/oceanic

Back 13

Himalayan mountains

Deep sea trench

Deep sea trench

Front 14

2 examples of Shear boundaries

-cotinental/continental
-oceanic/oceanic

Back 14

SAN ANDREAS FAULT (both)

Front 15

What are the characteristics of older crust?

Back 15

Further out from the mid ocean ridge

Cooler
Denser
Less bouyant
Deeper

Front 16

What is the result of a convergent boundary in each of the following:

-Continental/continental:
-oceanic/oceanic:
-Continental/oceanic

Back 16

Mountains

Island arcs

volcanic mountains.

Front 17

what plate boundary and plates caused the islands of Japan? the mariana trench

Back 17

ocean ocean convergence.

Front 18

There are two classes of shear boundaries. What are they?

Back 18

Transform fault-plates moving in opposite direction (San Andreas)

Fracture zone- plates moving in the same direction.

Front 19

What are hot spots? what did it create?

Back 19

A stationary source of volcanic activity. As the plate tectonic moves, it creates a chain of islands.

Hawaii

Front 20

What happens to aging volcanic rock from these hot spots?

Back 20

They begin to sink and coral reefs grow right where they begin to sink (ATOLL)