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Natural Calamities - Volcanoes (Active, Dormant, Extinct)

Grade 5ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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A volcano is an opening or rupture in the Earth's crust through which molten rock, hot gases, and ash escape. The molten rock inside the Earth is called magma, and once it reaches the surface, it is known as lava.

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The temperature of lava can range from 700∘C700^\circ C to 1200∘C1200^\circ C (1292∘F1292^\circ F to 2192∘F2192^\circ F).

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Active Volcanoes: These are volcanoes that erupt regularly or have erupted in recent history. Example: Mount Etna in Italy and Barren Island in India.

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Dormant Volcanoes: Often called 'sleeping volcanoes,' these have not erupted for a long time but have the potential to erupt again in the future. Example: Mount Kea in Hawaii.

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Extinct Volcanoes: These are 'dead' volcanoes that are unlikely to erupt again because they no longer have a lava supply. Example: Mount Popa in Myanmar.

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Volcanic emissions include various gases such as water vapor (H2OH_2O), carbon dioxide (CO2CO_2), and sulfur dioxide (SO2SO_2).

📐Formulae

Density (ρ) of Magma=Mass (m)Volume (V)\text{Density (}\rho\text{) of Magma} = \frac{\text{Mass (}m\text{)}}{\text{Volume (}V\text{)}}

T(K)=T(∘C)+273.15T(K) = T(^\circ C) + 273.15

Pressure (P)=Force (F)Area (A) (Higher pressure in the magma chamber leads to eruptions)\text{Pressure (}P\text{)} = \frac{\text{Force (}F\text{)}}{\text{Area (}A\text{)}} \text{ (Higher pressure in the magma chamber leads to eruptions)}

💡Examples

Problem 1:

During a volcanic eruption, the temperature of the flowing lava is recorded as 1000∘C1000^\circ C. Convert this temperature into Kelvin (KK).

Solution:

1000∘C+273.15=1273.15K1000^\circ C + 273.15 = 1273.15 K

Explanation:

To convert Celsius to Kelvin, we use the formula T(K)=T(∘C)+273.15T(K) = T(^\circ C) + 273.15. This represents the absolute temperature of the lava.

Problem 2:

Identify the type of volcano: A volcano in a specific region has not erupted for over 20002000 years, but scientists detect magma movement deep beneath it.

Solution:

Dormant Volcano

Explanation:

Since the volcano has not erupted for a long time but still has a magma source and the potential to erupt, it is classified as 'Dormant' or sleeping.

Problem 3:

Which gas, represented by the chemical formula CO2CO_2, is commonly released during a volcanic eruption?

Solution:

Carbon Dioxide (CO2CO_2)

Explanation:

Volcanoes release trapped gases from the Earth's interior, primarily water vapor, followed by CO2CO_2 and SO2SO_2 (Sulfur Dioxide).