Chapter 2: Geological Oceanography

Question 1

What are the World’s Ocean Basin?

Answer 1

1) Pacific
2) Atlantic
3) Indian
4) Arctic
5) Southern Ocean

Question 2

How did Earth and Oceans form?

Answer 2

Big Bang 15 bya

Question 3

Earth originated with solar system

Answer 3

4.5 bya

Question 4

Density stratification of molten earth was

Answer 4

Density = mass/volume

Question 5

Core: inner and outer

Answer 5

4000 degrees

Question 6

Inner

Answer 6

Iron and solid

Question 7

Outer

Answer 7

Iron, nickel alloy, gold, platinum, and uranium, and molten

Question 8

Mag field

Answer 8

Due to spinning inner core

Question 9

Mantle: lower and upper

Answer 9

1) Magnesium + iron
2) Lower solid, upper plastic (semisolid swirls)

Question 10

Crust

Answer 10

Oxygen, silicone dioxide, magnesium, irons

Question 11

Two kinds of crusts

Answer 11

Oceanic and continental

Question 12

Oceanic crust (basalt)

Answer 12

1) Density about 3.0 g/cm^3
2) Only about 5km (3mi) thick
3) Geologically young
4) Dark in color
5) Rich in iron and magnesium

Question 13

Continental crust (granite)

Answer 13

1) Density about 2.7 g/cm^3
2) 20 to 50 km ( 12 to 30 mi) thick
3) Can be very old
4) Light in color
5) Rich in sodium, potassium, calcium, and aluminum

Question 14

What shaped Ocean Basin?

Answer 14

1) Geological time scale
2) Continental move

Question 15

Initial evidence of continental drift

Answer 15

1) Shape of continents when we started exploring and mapping coast
2) Similar geo and fossils on opposite sides

Question 16

Alfred Wegener (1912)

Answer 16

Theory of Continental Drift, Pangea and Panthalassa

Question 17

Harry Hess

Answer 17

Seafloor Spreading

Question 18

What is seafloor spreading?

Answer 18

Magma from mantle rises up at mid-ocean ridges and make new seafloor while pushing crust

Question 19

Theory of Plate Tectonics

Answer 19

1) Mid-ocean ridges, trenches, and transform faults reveled by sonar
2) Active mid-ocean ridges
3) Sediment layers on seafloor near ridge is thin
4) Rock/sediment further away from ridge older than ones nearer ridge
5) Magnetic anomalies

Question 20

Lithospheric plates made of

Answer 20

Crust and uppermost part of upper mantle

Question 21

Plates can have any kind of

Answer 21

Crusts

Question 22

Plate float on

Answer 22

Plastic upper mantle equals to movement

Question 23

Plates move apart at ridges and collide at

Answer 23

The trenches

Question 24

Trench formation

Answer 24

When two plates collide one subducts

Question 25

Oceanic vs continental

Answer 25

Oceanic subduct

Question 26

Oceanic vs oceanic

Answer 26

Older oceanic subduct

Question 27

Continental vs continental (Does not form trench)

Answer 27

Neither subducts or uplift instead

Question 28

Trenches active geologically in these

Answer 28

1) Volcanoes, earthquake 2) Plates can also slide at shear boundaries (San Andreas Fault)

Question 29

New theory of plate tectonics

Answer 29

Convection currents and slab pull move plates

Question 30

How has Earth changed over time?

Answer 30

1) 200 mya: Pangeal/Panthalassa 2) 180 mya: Pangea = Laurasia + Gondvana

Question 31

What stories can be told by Ocean Sediments?

Answer 31

1) Lithogenous sediment: from breakdown of rocks 2) Biogenous sediment: from skeleton and shells

Question 32

Ocean sediment can reveal information about

Answer 32

Temperature, atmospheric gases at the time, pH of water and calcereous and siliceous ooze

Question 33

What are the main current geological features of ocean? 1. Continental Margins 2. Deep Ocean Basin

Answer 33

1) Continental Shelf: 120-200 m depth, submarine canyons, and shelf break 2) Continental Slope: 3000-5000 m depth 3) Continental Rise: Sediment from land 4) Active with passive margins

Question 34

Deep Ocean Basin

Answer 34

1) Most at 3000-5000 m 2) Abyssal plain 3) Seamounts 4) Trenchs (Marianna = 11,022 m, 36, 070 ft)

Question 35

Mid-ocean ridge and vents

Answer 35

1) Central rift valley 2) Hydrothermal vents

Question 36

Hot Spot

Answer 36

Stationary mantle plume vs windshield hypothesis

Question 37

West Coast of North America Sediment not able to

Answer 37

Accumulate due to steep slope and sediment is washed away

Question 38

East Coast of North America sediment is able to

Answer 38

Accumulate because of type of shelf