This page provides an in-depth look at plate movement and all its known causes. It's best to start without sharing the objectives because following the map activity, the gallery activity introduces the key ideas through images that students need to connect. Following this students work their way through a number of well chosen videos, animations, images and text based resources to complete a number of visually impressive worksheets, on Earth's structure, causes of plate movement, rifting and mantle plumes.
What causes tectonic plates to move?
Starter Activity - Plate Movement Map - Processes and Spatial Interactions
- Study the map of plate boundaries on the PDF and complete the map with the missing arrows to show plate movement
- Referring to the map discuss why the plates boundaries appear to be so jagged an uneven
Student Activity - A History of Plate Movement - Processes and Spatial Interactions
Watch the following video showing the history of plate movement and continentality (watch to 3.40mins)
Student Activity - The Mechanisms of Plate Movement? Processes
- Study the diagram of the Earth's structure and add the numbered box to correct place on the diagram
Student Activity - Heat Sources and Convection Cells - Processes
Watch the two videos and make the transcipt notes on the worksheet
Follow up the videos with the following sorting activity
Student Activity - Ridge Push and Slab Pull Processes - Processes
Study the following diagram and suggest how it helps explain plate movement
Read the text below and annotate the diagram to explain the process of Ridge Push and Slab Pull
The lithosphere thickens with distance (and time) away from the mid-ocean ridge. This is because it cools as it moves away from the ridge and the boundary between the solid lithosphere and the plastic asthenosphere becomes deeper. The result of this thickening with distance from the ridge is that the lithosphere/asthenosphere boundary slopes away from the ridge. The weight of the lithosphere on this sloping surface produces a downslope force. And since the asthenosphere is weak, the weight of the lithosphere near the ridge sliding down the asthenosphere "pushes" the older part of the plate in front of it
As lithospheric plates move away from mid-ocean ridges they cool and become denser. They eventually become more dense than the underlying hot mantle. At a subduction zone the denser of the two plated sinks under the less dense plate. During subduction, cool, dense lithosphere sinks into the mantle under its own weight, because it is denser than the mantle around it the process of subduction will continue. Therefore the weight of the subducting plate and the force of gravity drives its movement. Slab pull is considered the most important factor causing plate movement.
Student Activity - Plumes - Processes
Study the following gallery showing mantle plume and hotspots and annotate the diagrams in the worksheet to describe the characteristics of hotspots and to describe how they show plate movement.
Exam Question - Hotspots - Processes
With the use the diagram (2) explain the evidence to explain the presence of hotspot volcanoes (4 marks)
Explain two processes that explain plate movement (3+3)
To address this question responses should consider the role of convection cells, ridge push processes and slab pull. To gain the 3 marks responses should clearly locate the process within the mantle and/or plate boundary. The process should be accurately explained and clearly linked to how this leads to plate movement