Oceanography. Oceanography is the study of the deep sea and shallow coastal oceans.

Transcription

1 Oceanography Oceanography is the study of the deep sea and shallow coastal oceans.

2 Studying the Ocean Floor To determine the shape and composition of the ocean floor, scientists use techniques such as echo sounding (sonar), sediment sampling, and satellite observation. Single Beam Echo Sounding Multiple Beam Echo Sounding Single beam sound signal from the ship Signal echoes back to ship Multiple beam sound signal Seafloor Seafloor

3 Chesapeake Bay to Ocean

4 "Bathymetry" refers to the depth from the ocean's surface to features on the seafloor.

5 Chesapeake Bay to Ocean How Bathymetric maps are made

6 Chesapeake Bay to Ocean Identifying Ocean Floor Features

7 And Yet Even More Oceanography Abyssal Plain flattest area on Earth. Sediments fill any crevice immediately Seamounts underwater volcanoes Atolls form around extinct volcanoes. Coral structures. Continental slopes have canyons and extreme movement of sediment

8 Chesapeake Bay to Ocean Marianna s Trench

9 Chesapeake Bay to Ocean

10 CHAPTER 23 VOCABULARY continental shelf continental slope continental rise The Ocean Floor active continental margin passive continental margin submarine canyon turbidity current 23.2 The Continental Margin CHAPTER HOME SECTION OUTLINE

11 Chesapeake Bay to Ocean The east coast of the US is a passive margin. Distance in meters Shelf Passive Margin Continental margin Slope Rise Ocean basin Abyssal plain Distance in kilometers Sediment Continental crust Oceanic crust Lithosphere

12 Chesapeake Bay to Ocean Distance in meters Active Margin Continental margin Shelf Slope Trench Ocean basin Abyssal plain Distance in kilometers The west coast of the US is an active margin. Continental crust Accretionary wedge Subducting oceanic crust

13 CHAPTER 23 VOCABULARY continental shelf continental slope continental rise The Ocean Floor active continental margin 23.2 The Continental Margin CHAPTER HOME A continental margin can be active or passive. An active continental margin is found along a subduction zone or transform fault, is very narrow, and very steep. A passive continental margin is not located along any plate boundaries and is broad and less steep. passive continental margin submarine canyon turbidity current SECTION OUTLINE Distance in meters Active Margin Continental margin Shelf Slope Trench Ocean basin Abyssal plain Distance in kilometers Distance in meters Continental margin Shelf Passive Margin Slope Rise Ocean basin Abyssal plain Distance in kilometers

14 Chesapeake Bay to Ocean Waves Crest = top Trough = bottom Wavelength = crest to crest or trough to trough Wave Height = Crest to trough Amplitude = sea level baseline to top of crest or bottom of trough

15 Waves in the Sea Wavelength Most waves result from Crest Height Crest winds. A wave is described by its height, Trough wavelength, period, and speed. As a wave passes through water, the water particles move in a circular motion.

16 Waves in the Sea As the water depth becomes more shallow, wave motion is distorted and breakers form. Waves approaching a shoreline at an angle refract and approach the shore roughly head on. Swash, backwash, longshore currents, and rip currents move water and sediments on beaches. Longshore current Backwash Beach

17 Waves in the Sea Rip Currents form when high wind pushes water through a sand bar. The water that retreats is forces though this opening. Rip current footage

18 Shoreline Features Waves affect the shoreline by eroding and depositing materials. Sea cliffs, sea caves, sea arches, and sea stacks result from shoreline erosion. Longshore current Sea cliff Sea arch Sea stack

19 Shoreline Features Waves affect the shoreline by eroding and depositing materials. Sandbars, spits, baymouth bars, hooks, lagoons, and barrier islands result from shoreline deposition. Lagoon Spit Baymouth bar Longshore current

20 Oceans Tsunami

21 Oceans Tsunami

22 Ocean Floor

23 Surface Currents The Coriolis effect causes the deflection of moving objects toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. Coriolis game CZ -Coriolis Winds Currents

24 Chesapeake Bay to Ocean Effect

25 Surface Currents An ocean current is a continuous flow of water along a broad path in the ocean. Wind is the driving force of most ocean surface currents. Many surface currents come from either trade winds or westerly winds. noaa- currents video cz- global ocean currents Winds Currents

26 Global Ocean Currents Global Ocean Currents move warm and cold water around the globe.

27 Chesapeake Bay to Ocean The warm water gulf stream current makes Ireland much warmer than Canada even though they are at the same latitude and get about the same amount of sunlight.

28 Chesapeake Bay to Ocean Modeling ocean currents rubber ducky?

29 Chesapeake Bay to Ocean Accidental spills help us understand ocean currents.

30 Chesapeake Bay to Ocean

31 Chesapeake Bay to Ocean

32 ocean current map EAC CZ - Ocean Currents Global Ocean Currents Current systems are created by the Coriolis Effect and Wind. In the Northern Hemisphere, currents turn clockwise and warm water moves toward the poles and cold water moves toward the equator (convection currents)

33 Oceans Gyres places where currents meet and form a whirlpool like system.

34 Oceans Human Impact Great Pacific Garbage Patch

35 Oceans Human Impact

36 Currents Under the Surface Density is what drives ocean currents under the surface. When an area of water becomes more dense than the waters around it, the denser water moves beneath the less dense water, forming a flowing current. Temperature and salinity are two factors that influence the density of an area of water. The densest seawater comes from the polar regions. The density of water is also high in areas of high evaporation. Ocean Water Lab CZ - Cork Ireland Cold, salty deep currents Warm, less-salty, surface currents

37 Density of Water Salinity is the amount of salt in the water. Average salinity is 3.5%. Because of the salt, ocean water is denser than fresh water. Water with salt is more dense. Evaporation or the formation of ice may cause the salinity of water to increase. Cold water is more dense.

38 Currents Under the Surface An upwelling is a type of density current in which surface water is displaced and cold dense water rises to replace it. CZ Upwelling Surface water Surface winds Cold water upwelling

39 Chesapeake Bay to Ocean Upwelling occurs when surface water is blown back and cold nutrient rich water rises to the surface.

40 Thermocline Most energy is exchanged at the surface of the ocean. As you go deeper the temperature of the water decreases.

41 Chesapeake Bay to Ocean Surface Current movement of water caused by wind. Density Current movement of water casued by areas of more to less density. Waves movement in which water rises and falls regularly. Tides shallow water waves caused by gravitational forces of the sun, moon, and Earth.

42 Chesapeake Bay to Ocean Upwellings rising of cold, deep, nutrient rich water toward the surface. Tsunami sea wave caused by earthquake activity. Surf result of the formation and breaking of many waves.