Modelling ancient and modern magnetic fields

'Human magnets! Modelling ancient and modern magnetic fields, using your pupils'. In this Earthlearningidea, pupils use their own bodies to model the magnetisation induced in magnetite mineral particles by the Earth’s field of today: also the magnetic evidence within ancient rocks for ‘continental drift’.

The activity can be used to aid the understanding of remanent magnetisation in rocks. This in turn provides evidence of past magnetic fields of the Earth and is of great value in demonstrating the former latitudes of the continents, before their plate tectonic movement.

Many more activities about magnetism can be found on the website.

Ammonites: the ups and downs

The new ELI published today is 'The ups and downs of ammonites; how did they adjust their position in the sea?

The demonstration shows how some animals which are buoyant in water can change their depth in the sea. Explain that ammonites had a coiled shell, but that the soft body only lived in part of the outermost coil. Inside the rest of the shell, the space was filled with gas, which made the animal buoyant.
Demonstrate this, using a boiling tube full of air with a bung to represent the shell of the ammonite. The air-filled tube represents the gas- filled inner coils of the ammonite. The bung represents the living parts of the animal, which can move towards the neck of the tube or retract back into it.
Many more activities about bringing fossils back to life can be found in the Evolution of Life category on our website.

Hotspots - modelling the movement of a plate over a hotspot

Have you tried this ELI? 'Hotspots; modelling the movement of a plate across the globe'
After the activity pupils can understand the motion of one object (the card) relative to another (a point source of heat – a candle) and then be able to relate the card and candle model to the movement of a plate relative to a fixed source of heat in the mantle below. They can also use evidence of volcanic activity in the Pacific Ocean to deduce the on-going motion of the Pacific plate.
Many more activities about plate tectonics can be found on our website.

Environment differences between today and when the rocks formed

The new ELI today is 'Now and then – spotting the difference; how did the conditions differ between today and when the rock was formed?'

Between now (today) and then (when the rock was formed) how have these things changed?:
- temperature
- orientation
- humidity
- altitude
- visibility
- latitude
- pressure
- age
- life, invertebrates and vertebrates
This is a thought experiment, attempting to compare various aspects of the environment when the rock was formed, with conditions today.
Many more activities about past environments can be found on our website.