The Ocean - PowerPoint Presentation

Presentation on theme: "The Ocean"— Presentation transcript

Slide1

The Ocean Floor --subsurface topography--

Ch

13, section 2

(before the 1900’s scientists thought the ocean floor was completely flat)Slide2

Sonar (sound navigation and ranging)

--invented during WWI--

to find depth: use the formula:

depth= V x t (remember that you only want half the time)—units=meters…where velocity of sound in ocean water is about 1,500 m/sSlide3

Water pressure

Water Pressure

demo

(with 2L bottle)Water pressure increases with depth 

part of TitanicSlide4

Continental MarginSlide5

>>submarine canyons caused by erosion and underwater landslidesSlide6

ABYSSAL PLAINFlat area of ocean floorSlide7

Mid-Ocean Ridge

Divergent boundary

Sea-floor spreading

New sea floor formedSlide8

What do you notice about the shape of the mid-Atlantic ridge?Slide9

Seamount

Underwater volcanoes

If they reach the surface they form islands, like Iceland.

FYI—called guyots if flat-topped (due to erosion)Slide10

IcelandSlide11

TRENCH

At

convergent

boundaryEx: the Mariana Trench is the deepest known place on earth ---11034 meters (36200 ft) deepSlide12

Features of the Ocean Floor

(website—needs sound)Slide13

The Ocean Floor

Continental shelf

Seamount

Volcanic island

Continental slope

Continental shelf

Continental

slope

Abyssal plain

Mid-ocean ridge

TrenchSlide14

3D model of ocean floor(as a group)

After you build the ocean floor, use toothpicks and sticky labels to identify the following ocean features:

1. continental shelf

2. continental slope3. MID-ocean ridge4. abyssal plain5. seamount6. trench—should not be right next to mid-ocean ridge

(should be at

subduction

zone)Slide15

Omit section 3, except:Slide16

If you were able to walk along the ocean bottom from a beach, which feature would you reach after the continental shelf?

….continental slope

QuestionsSlide17

The area under water that is closest to the shoreline is the

A. continental shelf

B. continental slope

C. mid-ocean ridgeD. benthic Slide18

The __________ is the broad, FLAT part of the deep-ocean basin

A.

a

byssal plainB. continental shelfC. mid-ocean ridgeD. benthic Slide19

At which point in the diagram above would hot magma most likely rise through the ocean floor to eventually form a volcanic island?

Point BSlide20

Which is most like a mountain RANGE?

A. A seamount

B. A

guyotC. The abyssal plainD. The mid-ocean ridgeNote: A seamount is a single underwater mountain.