Why tectonic plates move? Convection Currents

What is convection currents?

1. Convection currents are movements of heat within the mantle. Materials in the mantle are heated by the core. The heat will cause the mantle material to expand, rise and spread out beneath the plates.

mantleconvection

Video animation of convection currents:

https://www.youtube.com/watch?v=ryrXAGY1dmE

https://www.youtube.com/watch?hl=en-GB&v=Kpoko_l34ZE&gl=SG

Describing the process:

2. The hot mantle material will cool slightly and sinks, pulling the plates along.

3.The sinking mantle material will heat up again as it nears the core and the whole process repeats.

4. As a result, plates will be dragged along or move away from each other.

Slab-pull force

A slab-pull force will cause a denser oceanic plate to be forced beneath a less dense continental plate or oceanic plate in  a process called subduction.

As the plate subducts, it will pull the rest of the plates along.

Downward moving and rising portion of convection currents

The subducting plate will drive the downward moving portion of the convection currents.

At the other end of the convection current, the mantle material will drive the rising portion of the convection currents

Advertisements
This entry was posted in Term 1 and tagged , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s