1 / 12

The Earth’s Oceans and Plate Tectonics

The Earth’s Oceans and Plate Tectonics. Oceanography Unit #1. Our Earth. Earth is between 5.0 and 7.0 billion years old . Crust Mantle Outer core Inner core. The Earth’s Crust. Asthenosphere – an area of weakened crust and molten upper mantle.

tahlia
Download Presentation

The Earth’s Oceans and Plate Tectonics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Earth’s OceansandPlate Tectonics Oceanography Unit #1

  2. Our Earth • Earth is between 5.0 and 7.0 billion years old. • Crust • Mantle • Outer core • Inner core

  3. The Earth’s Crust • Asthenosphere– an area of weakened crust and molten upper mantle. • Lithosphere – the rigid hardened crust. • Crustal types: • Oceanic Crust– found beneath the ocean basins • Continental Crust – found beneath the continents and margins

  4. Crustal Comparsions

  5. Earth’s Hydrosphere • Oceans are approx. 4.0 billion years old. • Oceans cover approx. 71% of the earth’s surface. • Water? • Oceans = 97.22% • Glaciers = 2.15% • Ground water = .62% • Atmosphere, lakes, rivers, etc. = <.01%

  6. The Ocean Basins Southern Ocean – combination of the most southern Pacific, southern Atlantic, and southern Indian; surrounding Antarctica.

  7. Ocean Topography • Continental shelf – submerged edge of the continent; most biologically active. • Continental slope – descends from shelf down to the deep sea-floor. • Continental rise – sediments that accumulate at the slope’s base. • Abyssal plains – most of the ocean’s floor; avg. depth = 4.0 km. • Seamounts – submarine volcanoes • Trenches – found at base of slope; depth >6.0 km.

  8. Mid-Ocean Ridge System • “Spreading centers”; crustal expansion. • Largest geographical feature on planet. • Total length is over 65,000 km.

  9. Plate Boundaries • Divergent: • Two or more plates are directed away from each other. • Mid-ocean ridge system • Numerous volcanic eruptions and earthquakes. • Volcanic islands such as Iceland, Azores, and Ascencion. • Lateral: • Two plates slip past each other. • San Andreas Fault (CA). • Numerous large earthquakes

  10. Plate Boundaries • Convergent: • Crustal plates are directed towards each other. • Two continental plates collide: • Build up of crust in to mountain ranges. • Himalayan Mountains • One continental plate and one oceanic plate collide: • Createssubduction zones. • Japan Islands, New Zealand, Andes

  11. Subduction Zone

  12. Hotspots • Areas where magma punches a hole in thin, weak crust above; Stationary. • Hawaiian-Emperor island chain:

More Related