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the two main types of volcanoes !

1) Glassware: a large container (bowl, measuring cup, etc.) and a glass yogurt pot.

2) Protective equipment : Blouse, glasses, hair tied.

3) materials: flour, water, vinegar, baking soda.

4) about 10 min the time to prepare and make the mixes, but no waiting time, the result appears directly.

5) The goal is to answer this question: why are there two types of volcanoes? This is due to the viscosity of the magma. Indeed a viscous magma will be the source of an explosive volcano while a more fluid magma will be the source of an effusive volcano. Why ? To understand this mechanism, I will perform an experiment.

6) The baking soda should not have eye contact.

7) Glasses, to avoid the projection of bicarbonate in the eyes.

8) Why will a viscous magma be the source of an explosive volcano while a more fluid magma will be the source of an effusive volcano?

9) Protocol to model an effusive volcano:

-Mix in a container 50g of flour with 75 mL of water.

-Add 75 mL of vinegar to this mixture. Mix well to avoid the presence of lumps.

-Pour this mixture into the glass yogurt pot. Fill it almost to the brim.

-Add a teaspoon of baking soda. Mix quickly and watch!

Protocol to model an explosive volcano:

-Mix in a container 75g of flour with 50 mL of water.

-Add 50 mL of vinegar to this mixture. Mix well to avoid the presence of lumps.

-Pour this mixture into the glass yogurt pot. Fill it almost to the brim.

-Add a teaspoon of baking soda. Mix quickly and watch!

10) If we compare the two experiments, we notice that the more viscous paste contains larger gas bubbles than the more fluid paste.

11) the gas in the magma has more difficulty escaping when the magma is more viscous. In addition, the more viscous magma leaves the volcano less easily. Consequently, large amounts of viscous magma and therefore gases accumulate in the magma chamber, until the pressure is such that the volcano will eventually explode!

12) In conclusion, for effusive volcanoes, the more fluid magma can more easily flow out of the volcano. Eruptions are therefore more frequent but less dangerous!