History of Planet Earth: Volcano, Layers & Movements

Changing Earth 

The surface of the Earth is ever-changing. Changes can occur quickly or slowly.  

The changes could damage landforms or may raise the Earth’s surface to produce new landforms. 

Fast changes: Earth changes might take place slowly over time or quickly. Natural calamities like earthquakes, volcanoes, tsunamis, and landslides have the power to severely alter the surface of the Earth very rapidly. 

Slow changes: The landforms slowly become smaller as a result of weathering and erosion. The rocks are relocated, and then they start to create a new landform somewhere else. The erosion of mountains and canyon formation are two examples of slow processes. 

Introduction: 

Volcano 

A volcano is a crack or opening in the crust of the Earth. Hot gases and melted rock from deep under the Earth’s crust rise to the surface when a volcano erupts.  

The Earth’s surface can be altered by volcanoes by creating new land, islands, and mountains very rapidly. 

 Furthermore, they expand existing land or enlarge islands. 

Explanation: 

Volcanic eruptions 

When molten rock erupts from the Earth’s crust, it forms a landform called a volcano, which is typically a mountain. 

A volcano is a mountain that gives access to a pool of molten rock (magma) under the Earth’s surface. Molten rock and gas erupt from a hole in the Earth known as lava. This liquid may gently leak out of a ground fissure or fracture, or it may explode violently into the air. Volcanic eruptions might cause a lot of damage. However, they also produce new landforms. 

Magma: Molten rocks below the surface of Earth are known as magma. 

Lava: Molten rocks flowing on the surface of Earth are called lava. 

Erupts: To spew out melted gas, ash, and rock. 

Crater: The steep-sided mouth of a volcano is called a crater. 

As it(lava) comes through the volcano’s opening, it glows red. It turns into rock when it cools. 

A vent, or opening, in the crust of the Earth’s surface, allows hot, molten rock, known as magma, to erupt during a volcanic eruption.  

Lava is the term for the magma that a volcano releases. 

 

Post effect of volcanic eruptions 

Magma pieces are thrown into the air during powerful volcanic explosions.  

These pieces settle into tiny stones known as volcanic dust or volcanic ash.  

Volcanic dust can travel thousands of kilometers on the wind. The area miles around a volcano might be covered in volcanic ash. 

Volcanoes also release steam and toxic gases. These gases can sometimes be combined with ash and other heated material. This mixture travels outward in a destructive, fiery cloud. 

Fig. no. 6 Post effect of a volcanic eruption 

Earth`s layers 

Earth has three layers: Crust, mantle, and core. 

Crust: The outermost layer of the Earth. 

Mantle: The second layer of Earth is called the mantle. 

Core: The inner layer of Earth is called the core. 

Movement of plates on Earth`s crust 

The crust of the Earth is made of large plates that fit together like a jigsaw puzzle. These plates sometimes move. 

Magma, a mixture of rock and gases, lies between the Earth’s crust and the mantle. 

When two plates collide, the upper piece slides on top of the lower one, pushing the lower section downward. Between two plates, magma is pressed up. 

These volcanoes are highly explosive due to the hot gases in the magma. 

Where do volcanoes occur? 

At the borders of tectonic plates, volcanoes are most commonly found.  

For example, the plate boundaries that surround the Pacific Ocean are places where a lot of volcanoes occur.  

As a result, the region is sometimes referred to as the Ring of Fire. 

 

Causes of volcanoes 

Tectonic plate boundaries are places where plates collide, separate, or pass one another.  

Most volcanoes are situated where plates are separating or coming together. 

Volcanoes can also develop in regions where two plates are slowly separating. In between the plates, as they separate, molten rock rises. Fissure eruptions are the result, and lava spills out over the Earth as a result.  

 

 Summary 

• The surface of the Earth is ever-changing. Changes can occur quickly or slowly.  
• A volcano is a crack or opening in the crust of the Earth. Hot gases and melted rock from deep under the Earth’s crust rise to the surface when a volcano erupts.  
• A volcano is a mountain that gives access to a pool of molten rock (magma) under the Earth’s surface.  
• Magma pieces are thrown into the air during powerful volcanic explosions.  

• Earth is made up of three layers: crust, mantle, and core. 
• When two plates from the Earth`s crust collide, the upper piece slides on top of the lower one pushing the lower section downward. 
• Volcanoes are most commonly found at the borders of tectonic plates.  
• The boundaries of the Pacific Ocean are places where a lot of volcanoes exist.