Warm Up 2/4 • 1. What is the biggest difference between an ROV and an AUV? • 2. Name the ROV that explored the Titanic. • 3. Name the HOV that explored hydrothermal vents. • 4. Name the bathyscaphe that traveled to the Mariana Trench • 5. What is one piece of information a scientist could gather from an ocean corer?
James Cameron Challenger Deep 43” diameter of internal cabin!!! 70 minute ascent!
Ocean Geography • Earth is 71% water • Northern Hemisphere • Southern Hemisphere Is that water evenly distributed over the earth? Nope! 61% ocean 80% ocean
Water, water, every where, Nor any drop to drink.
Ocean Geography • There are ____________ large ocean basins. • 1. • 2. • 3. • 4. • “World Ocean” = term used by oceanographers Are these oceans separate?
Ocean Diagrams in Notes • Label, color code, cut and paste into notes
Ocean Geography What’s the difference between an ocean and a sea?
Structure of the Earth • Big Bang explosion 4.5 billion years ago • Cosmic dust particles collide • Condensed to a molten earth • Denser particles flowed to center D = mass volume Formation of Earth
Figure 2.03 Layers of the earth cake
Earth’s Layers Model • Materials: • Earth’s Layers handout • Scissors • Colored pencils • Glue sticks • textbook • Procedure: • Fill in blocks of 4 main layers of earth on lower right side • Cut and paste blocks next to corresponding wedge • Cut and label portions of earth’s interior (terms on left side) • Use textbook as guides
Layers of the Earth • Core • Inner Core – solid • Outer Core – liquid • Mantle • Thought to be solid, but so hot that it flows like lava • Swirls and mixes like boiling soup = convection currents
Layers of the Earth • Mantle (continued) • Asthenosphere • Portion of upper mantle • Location of convection • Lithosphere • Upper mantle into the crust • Where plates located
Layers of the Earth • Crust • Thin in comparison to core and mantle • Rigid skin on top of mantle • Two kinds • Continental • Oceanic Ex) Gravy skin Banana pudding Crust and Mantle - Wiz
Structure of the Earth • OCEANIC CRUST • Basalt • 5km “thin” • “young” • Dark in color • Iron, magnesium =DENSE • CONTINENTAL CRUST • Granite • 20-50km thick • “old” • Light in color • Sodium, potassium, calcium, aluminum
Continental Drift Theory • Alfred Wegener • 1912 • Supercontinent Pangaea What is up with these drifting continents, y’all?
Similarities in: • 1. types of fossils (Mesosaurus) • 2. shape and fit of continents and • rock formations; • 3. age and structure Continental Drift Theory
Plate Tectonics Theory 1950s • Entire surface of earth moves, not just continents • Lithosphere- • crust and uppermost mantle • Plates- broken up pieces that move over the more “plastic” (fluid) asthenosphere REVIEW: What’s the asthenosphere famous for??? CONVECTION CURRENTS!!
What crazy awesome technology developed during WW2 helped to validate the Theory of Plate Tectonics??????
Mid-Ocean Ridge • discovered by sonar after WWII • chain of submarine volcanic mountains • Largest geological feature on the earth. • Displaced from side to side by transform faults (cracks) Mid-Atlantic Ridge East Pacific Rise
Sea Floor Spreading (cont’d) • Sonar also found trenches, mostly in the Pacific • Tons of geological activity along mid ocean ridges. • Earthquakes- near ridges • Volcanic activity- near trenches
Distribution of earthquakes and volcanoes associated with plate boundaries
Significance of Mid-ocean ridges • Geologic ages- rocks near the ridge are “young” compared to rocks far from the ridge • Very little sediment near the ridge- and an increase in sediment further from the ridge • Magnetic anomaly bands • Bands of rock on seafloor parallel to mid-ocean ridges • Alternate between normal and reversed magnetization • Mirror images on opposite sides of ridge
Warm up 9/10 • Answer the following in complete sentences: • In what state of matter does the inner core exist? • What ocean has the greatest average depth? • What hemisphere contains the greatest percentage of ocean water? • What term from yesterday’s earth picture does this diagram represent?
Warm up 9/11 1. Identify and describe two differences in characteristics of rock near a mid-ocean ridge as opposed to further from the ridge. 2. Describe two of the three pieces of evidence that supported Wegener’s Continental Drift Theory. 3. What do the black and white stripes on the diagram below represent?
Agenda 9/11 • Finish seafloor spreading lab • Resume notes • Tsunami videos, article, questions
Magnetic anomaly bands prove seafloor not created all at once but cooled from molten material at different times in geologic history
Creation of the Sea Floor • Pieces of oceanic crust separating at mid-ocean ridges create cracks called rifts • Rifts release pressure (remove cap from soda bottle) • Allow molten material (bottled up) to reach earth’s surface, cool, solidify and form new crust
Creation of the Sea Floor • Seafloor spreading= process by which the sea floor moves away from the mid-ocean ridge to create new sea floor • Occurs at a divergent boundary (moving away) Bill Nye Seafloor