Creating Nature’s Scary Wonder at Home – Underwater Volcano DIY

If you’re thinking that this is another article where we talk about lava and volcanos, you are absolutely right! And if you also thought that this was going to be just as fun as last time, you’re right again. Wow, aren’t you on fire today! 

This cool science experiment is not only fun to look at, but it also demonstrates the scientific fact that hot water rises and cold water sinks. In fact, this is precisely the case with ‘hydrothermal vents’ – nature’s own underwater volcanos.

Hydrothermal Vent

What a monstrous sight, right? That’s a hydrothermal vent somewhere in the depths of the Pacific Ocean.

A hydrothermal vent is the result of seawater seeping down through fissures in the ocean crust. The cold seawater is heated by hot magma. The now heated water comes back to the surface to form the vents. Seawater in hydrothermal vents may reach temperatures of over 400 degrees celsius. Hydrothermal vents are known to exist in the Pacific and Atlantic oceans. Most are found at an average depth of about 2,100 meters (7,000 ft) on the seafloor. Hydrothermal vents continuously spew super-hot, mineral-rich water. The hottest of such vents are called ‘Black Smokers.’ They spew mostly iron and sulfide, which combine to form iron monosulfide. This compound gives the smoker its distinctive black colour.

Things you’ll need:

1. Small bottle
2. Large bottle
3. Hot (lukewarm) and cold water
4. A pair of scissors
5. Red/orange food colour/Water colours
6. Paintbrush
7. String

Method:

1. Cut a long piece of string. Tie one end firmly around the neck of the small bottle.
2. Tie the other end of the piece of string around the neck of the small bottle to make a loop.
3. Pour cold water into the large glass jar until it is about three-quarters full.
4. Fill the small bottle with hot water. Add food colouring to turn the water red/orange.
5. Hold the small bottle by the loop of string. Lower it gently into the jar of cold water
6. The hot red water rises from the small bottle like smoke from an erupting volcano!

But why is this happening? 

The “underwater volcano” is created because hot water rises and cold water sinks, just the way it happens in hydrothermal vents. This is because of the change in water’s density due to temperature difference. The particles of the hot water (less dense) are moving faster than the denser particles of the cold water. As a result, when we placed the bottle into the container filled with cold water, the hot water in the bottle started to rise out of the bottle and circulate to the top of the container because it is less dense than the surrounding cold water. Less dense fluids rise and more dense fluids sink. The red hot water then remained at the top of the container and created what looked like an erupting volcano.

There you have it! Your very own homemade hydrothermal vent (of sorts) is ready! Did you enjoy this experiment? Share your experience with us in the comments below.

Also read about the Taal volcano’s effects!