Lecture Notes – Chapter 9 9.1 The Interior of the Earth The Earth’s interior _______________________________________ Earth Layer Crust Mantle Core Thickness Temperatures Continental Drift: In the early 1900’s German scientist, _____________ theorized that a “supercontinent” _______________ existed ______________ years ago. Wegener’s EVIDENCE OF CONTINENTAL DRIFT Wegener’s Continents Fern Fossils Dino Similar Evidence Fossils mountains Rejecting the Hypothesis Why? _______________________________________________________ 9.2 Plate Tectonics Wegener’s theory ____________ the mid-_______’s, when structures on the ________________________ of a mechanism for the _________ of continents. Convection Current: Movement of ______________ (a fluid) caused by changes in ___________________ or temperature. Draw a convection current Earth’s Major Roles Plate tectonics theory: the uppermost __________ & overlying ______, = strong, _________ layer: the ______________________. Lithosphere: The _____ outer shell of Earth, consisting of the ____ and the rigid upper ________. The lithosphere is made up of large pieces called _______plates Asthenosphere: The zone of the ________________ the lithosphere that consists of _______________________. It is believed that the asthenosphere _____________________________, thus causing the tectonic plates to move. Draw a picture of the Convection Currents found in the Earth How many major plates are there? ____ Which one do you live on?___________ Types of Plate Boundaries Divergent boundaries (also called __________ centers) - two plates move ______. _______________ boundaries - two plates ___________________. _____________ fault boundaries - two plates ________________ each other (_______ the production or ____________ of the lithosphere). Draw a picture below of each of the boundaries. Include arrows that show movement of plates relative to each other. Divergent Convergent Transform 9.3 Actions at Plate Boundaries Divergent Boundaries Oceanic ridges - continuous _________ zones on _________________ basins. Rift valleys - ________________ structures Seafloor spreading ___________________ (crust) lithosphere. What is being formed in East Africa due to a rift? Convergent Boundaries A ____________________ zone - one ______________________________ into the ______________ beneath a second plate. Convergent Zone Oceanic- Type Continental Oceanic-Oceanic ContinentalContinental Can produce what? Examples Transform Fault Boundaries - plates ________________________ without destroying the lithosphere. Transform _________ - Most join two segments _______________________. Which plate is subducting into the North American plate? ___________________ 9.4 Testing Plate Tectonics: • Today we know that the ______________ floor is ______________ • Scientists have ___________ on the ocean floor and they now ____ that ____________ lies along the _____________________ and _____________ crust extends ________from this plate boundary. • Scientists have ____________________ with alternating ______________________ extending from the mid-ocean ridge. Evidence for Plate Tectonics Ocean ____________________ on the _____________of seafloor sediment __________________ hypothesis predictions. ____________ oceanic crust is at ridge crest, and the ________________________________________________margins. Evidence for Plate Tectonics ___________ ____________ - concentration of heat in mantle capable of producing ___________________ to Earth’s surface • Hot spot evidence ____________________________ the Earth’s surface. Draw and describe the hot spot beneath the Hawaiian islands: 9.5 Mechanisms of Plate Motion ____________ occurring __________________ is the basic driving _________ for plate ________________. • _____________ flow - motion of matter resulting from _____________ _____________________. Draw a convection current (use arrows, hot/cold and high/low density Causes of Plate Motion Slab-pull - _______________ oceanic crust ________ into mantle and ________________ the trailing lithosphere along.. Ridge-push causes oceanic lithosphere to slide down the sides of the oceanic ridge _________________________________ Mantle Convection • masses of ________________________ material that ____________ toward the ________, (leads to __________________). • _________________________________ within Earth causes thermal _________________ in the mantle that ultimately ________________.