Ch. 20 The Ocean Basins Journal Question 1: Why do Earth’s oceans matter????

Ch. 20 The Ocean Basins Journal Question 1: Why do Earth’s oceans matter???? What do you know about “El Nino”? (as it pertains to Global Science)

70 % of Earth’s surface Oceans interact with atmosphere  influence climate and weather patterns Part of natural processes (ecosystems, biogeochemical cycles, plate tectonics) Habitat for many organisms Food source Journal: Why do Earth’s oceans matter????

Journal Questions 2. What do you think the bottom of the ocean looks like? Do you think it looks the same in all places around the world? Why or why not? 3. How do you think scientists explore regions of the ocean floor too deep for scuba gear?

Video Clip Monitoring the World’s Oceans

20.1 The Water Planet Divisions of the Global Oceans 3 Major Oceans Atlantic Pacific Indian Seas: smaller areas of a particular ocean that are surrounded by land.

Exploration of the Ocean What is oceanography???? What does an oceanographer do??? Oceanography: The study of the physical characteristics, chemical composition, and life forms in the ocean.

Submersibles: Underwater research vessels – Piloted by people – Robotic (remote controlled) BathysphereBathyscaph

SONAR Review from reading…… What does sonar stand for?

SONAR Sound Navigation and Ranging Its all in the name ….. Observing what this acronym stands for, what might the name have to do with how sonar works?

SONAR Sound Navigation and Ranging Active sonar sends out a pulse of sound The pulse reflects when it hits an object The reflected sound waves are received by the investigators receivers.

What might be the uses of SONAR? Mapping Ocean Floor Topography Measuring the Depth of Ocean

20.2 Features of the Ocean Floor Two Major Areas: – Continental Margins – Deep Ocean Basins

Features of the Continental Margins: Continental Shelf Continental Slope – Submarine canyons – Continental rise

Deep Ocean Basins Trenches – Caused by converging plate boundaries, oceanic crust is subducted Abyssal Plains Mid-Ocean Ridges – Created by diverging oceanic plates Seamounts – Submerged volcanic mountains associated with hot spots.

Article “Rocket Plunge to Deep End of the Planet” First Read: What is the purpose of the article? Underline major points Circle Key words or phrases

Journal: According to Mr. Broad, “The deep sea is much harder to explore than outer space.” Does this surprise you? Why or Why not? What are some factors that make deep-sea exploration so difficult?

Using evidence from the article, discuss in your group…. What is unusual about the way Mr. Cameron’s submersible travels? When was the last time people descended to the Challenger Deep? What is the significance of this? What are three innovative factors in the submersible’s design?

20.3 Ocean Floor Sediments How are ocean sediments formed???? River Run off Shore line erosion Glacier Erosion Remains of organisms that sink The sediments in the ocean are sorted by size….. What does this statement mean???

Sources of Deep Ocean Sediment Inorganic Sediments: Rock Particles – How do these rocks get to the ocean floor??? Organic Sediments: Produced by living organisms – What are 2 examples of organic sediments??? Chemical Deposits – During some chemical reactions, solids are formed: precipitates – Ex. Nodules

Classification of Sediments Muds – Very fine silt and clay sized particles – Red clay Ooze – Soft organic sediment – Calcareous ooze: composed of calcium carbonate – Siliceous ooze: composed of silicon dioxide

In class: Density Review/Preview When have we discussed density this year??? What do you remember about density? We have two cubes at each of our table groups….. – Which is more dense? – How do you know? (Justify your answer) – Design a procedure to test your assumption