Fluids, friction and failure

The first ELI for 2012 is 'Fluids, friction and failure; how can unseen fluids affect the movement along faults and glacier beds?' This is a simple test of the angle at which friction is overcome and a drinks can begins to slide down an inclined board. Using a drinks can with small holes at the bottom results in water seeping out on to the surface of the board which reduces the friction.
The ELI website has over 100 Earth-related practical activities - use the search engine or search for a topic or category to find an idea which will stimulate and motivate your pupils.