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Jelly Earthquakes

Public summary: 

Fault lines, tectonic plates, subduction modelled through slabs of jelly.

Making earthquakes happen in large slabs of jelly.
Useful information
Kit List: 

- 700-1000g of jelly
- 10l of water
- Cotton Wool
- A blue box as a jelly mould
- A Sharp Knife to cut the Jelly
- corrigated card (or even better plastic)
- Gaffer Tape

- OPTIONAL Criticool maybe used with power to cool jelly while not in use


Making the jelly

Mix up the jelly (it should be 6-10x the normal strength - I found this easiest in a saucepan, in a sink full of hot water so it doesn't cool down too fast.) pour it into the box and add cotton wool in smallish puffed out lumps and try and distribute it throughout the jelly. Leave overnight to set.

Make a mould and if we have corrigated plastic - integrating it into the mould would be a really good idea.

Making the plates (do this before the visitors are present)

Cut the lump of jelly in two. Stow knife away somewhere safe. Then get some corrugated card and strip the paper off one side, so the corrugations are visable. cover the back with something waterproof like gaffer tape (or the card will go soggy), then attach this onto the faces of the fault...

The two lumps of jelly should be placed on pieces of card to stop them sticking to the table

Making earthquakes.

Push the two lumps of jelly past each other slowly and it should stick and slip making the jelly wobble - forming earthquakes.

Other things to talk about.

Drag fingernails across a blackboard/ steel across steel/ bow across violin strings - all cases of slip stop frictionas well as squeaking beaks and may others

Risk Assessment
Date risk assesment last checked: 
Tue, 01/01/2019
Risk assesment checked by: 
Date risk assesment double checked: 
Wed, 12/12/2018
Risk assesment double-checked by: 
Risk Assessment: 

Using two large lumps of jelly dragging past each other to show stick slip friction and how earthquakes are made... possibly with fingernails on blackboards, or violin bows as well.

Hazard Risk Likelihood Severity Overall Mitigation Likelihood Severity Overall
Jelly Ingestion of jelly by children, which has been sitting out in the warm (possibly culturing bacteria). 2 2 4 Keep jelly in fridge as long as possible, and don't let the kids eat it.
If ingested, warn the parents that there are some germs in what their child has just eaten, and to see a GP in the unlikely event of the child having symptoms of food-poisoning or tummy upset.
1 1 1
Knife Possible cuts when cutting jelly. 2 2 4 Knife is only required for setup stage, do not leave it around during the experiment.
Call first aider in case of injury.
1 1 1
Dropped jelly Slip hazard 2 2 4 Don’t let children play with jelly off the table. Clear up any dropped jelly immediately.
Call first aider in case of injury.
1 1 1