Last week we gave you the formation of asymmetrical sand ripple marks by a unidirectional current in a washbowl, so we suspect that a number of you have guessed that this week, the Earthlearningidea is the formation of symmetrical sand ripple marks by an oscillating current in a tank. Click here to view the activity. A video clip is also available, see post below.
As always, please send us your comments and suggestions and any relevant photographs you have. We should appreciate photos of pupils trying out any of these activities.