Cause of Plate Motions - PowerPoint PPT Presentation

1 / 10
About This Presentation
Title:

Cause of Plate Motions

Description:

17.4 Cause of Plate Motions Mantle Earth s interior between the crust and the core Large-scale motion is believed to be the mechanism that drives the movement of ... – PowerPoint PPT presentation

Number of Views:72
Avg rating:3.0/5.0
Slides: 11
Provided by: Natalie155
Category:

less

Transcript and Presenter's Notes

Title: Cause of Plate Motions


1
17.4
  • Cause of Plate Motions

2
Mantle
  • Earths interior between the crust and the core
  • Large-scale motion is believed to be the
    mechanism that drives the movement of tectonic
    plates

3
(No Transcript)
4
Convection
  • Transfer of thermal energy by the movement of
    heated material from one place to another
  • Ex. Boiling water
  • Heat comes from radioactivity within the mantle

5
Convection Currents
  • Cycle of warm water rising and cool water sinking
  • The cooling of matter causes it to contract
    slightly and increase in density
  • then it sinks due to gravity
  • Warmed matter is then displaced and forced to rise

6
Convection Currents
  • Develop in the mantle
  • Move the crust and outermost part of the mantle
  • Transfer thermal energy from Earths interior to
    its exterior

7
  • Rising material spreads out, lifts and splits
    lithosphere at divergent boundaries
  • Downward movement pulls convergent boundaries

8
Ridge push
  • Tectonic process associated with convection
    currents
  • Occurs when the weight of an elevated ridge
    pushes an oceanic plate toward a subduction zone

9
Slab pull
  • Tectonic process associated with convection
    currents in Earths mantle
  • Occurs as the weight of the subducting plate
    pulls the trailing lithosphere into a subduction
    zone.

10
In-Class Assignment/Homework
Write a Comment
User Comments (0)
About PowerShow.com