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Hot Spots PowerPoint Presentation

Hot Spots

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Hot Spots

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Presentation Transcript

  1. What They Are • Their Characteristics • How They Behave • How We Know What We Do • Why You Should Know Hot Spots

  2. Definition • A volcanic center, 60 to 120 miles (100 to 200 km) across and persistent for at least a few tens of million of years, that is thought to be the surface expression of a persistent rising plume of hot mantle material. Hot spots are not linked to arcs and may not be associated with ocean ridges.

  3. Diagram of a Typical Oceanic Hot Spot

  4. Convection in the Earth’s Mantle

  5. The Hawaiian Islands & theHawaiian-Emperor Seamount Chain

  6. Mantle PlumeNote: This concept is being debated…

  7. Possible Motion of Heated RockInside the Earth

  8. Compositional vs. Mechanical Layering

  9. Earth’s Major Plates

  10. Hot Spot Time Progression

  11. Life Cycle of a Typical Oceanic Hot Spot

  12. USGS Map of Worldwide Hot Spots

  13. Hawaiian Island Hot Spot Track

  14. Yellowstone Hot Spot Track

  15. Latest Ideas • Hot Spots may be related to huge blobs of magma that rise from within the mantle and pool against the base of the lithosphere • May not be associated with “plumes”

  16. Mantle Plume Concept Phasing Out? Some geologists think that the mantle plume idea isn’t holding up; they think they can explain magma melting by drops in pressure, rather than deep-seated heat sources…

  17. Summary • ~50-100 miles wide • Live for 10’s of millions of years • Are fixed in the mantle • Are NOT linked to arcs • May not be associated with ridges • Have a life cycle • Leave a track of volcanic features on the landscape (or seascape)