Underwater Volcano

We create an underwater volcano by placing a conical flask of hot coloured water in a tank of cold water. The hot coloured water rises through the cold, demonstrating convection. Physics - Energy And Radioactivity - Learning Points. Heated liquid or gas rises and is replaced by colder water or gas sinking. Convection currents are used by glider pilots and birds to gain altitude. Convection currents are caused by a drop in density. A Twig Experiment Film. Let students experience real experiments in lab conditions anywhere, from setup, method all the way through to analysis and real-world application.