Fact about Volcanoes

 How are Volcano formed ?

Volcanoes are Natural phenomenon that occur every where, but some places are more prone than the others. The molten rock and gas in the mantle called magma pushes its way upward and pours to the surface through crack in the crust , this is volcano. There are different types of volcano; some are explosive others are not, and all erupts as spectacularly as we see on the television. Some eruptions takes place unexpectedly, But others can be predicted, which is very important for the people living near a volcano.

Why do we have different types of volcano ?

Since material coming out of the earth's core is different in different areas, the resultant changes are also different. If the magma is very hot, more than 1000 degree C, it is dark, thin and mostly flows quietly. The side of such volcanoes have gradual slopes. Colder, and hence more viscous, magma often erupts in explosion. The volcanic cone is steeper. Because of the heat in the Earth's core, geysers (water fountains), solfataras (discharge of hot sulfuric gases),and hot water sources are found near the volcano. These often used for heating in places such as iceland .

How can we predict volcanic prediction eruption ?

Because of volcanoes are highly erratic, it becomes very difficult to predict volcanic eruptions. But there are ways of saving lives. Early tremors and earthquakes are often sign of volcanic eruption -gases are emitted and the volcano expands by a few centimeters to a meter . The volcanologist carefully observed these sign. In 1991, before the eruption of the Pinatubo in philippines, these sign were interpreted correctly and over 10,000 people were moved to safer palaces. However, people often do not believe the scientists, prediction. In 1985, before the eruption of Nevado del Ruiz in Columbia, though the danger was predicted every early, the authorities did not react quickly and, as a result, 25,000 people died.

Why do people live near volcanoes ?

Farmers prefer to settle near volcanoes because the soil is very fertile due to the lava and volcanic ash deposits. When the volcano erupts, people leave the place for some time, and return to the risk zone after the eruption because the safer places are already inhabited, More over, for many people the around the volcano is home. which they do not want to leave.

wikipedia link for more details:-

https://en.wikipedia.org/wiki/Volcano#:~:text=A%20volcano%20is%20a%20rupture,magma%20chamber%20below%20the%20surface.

How did we discover that the Earth is round ?

 About 3000 year ago people believe that the earth was flat. But people wondered why ships disappeared at the horizon. Sailor too returned from journeys and were proof that ships did not fall off the edge of the Earth. The simplest explanation was :the Earth must be round.The final proof come in the year 1522 after the expedition of Ferdinand Magellan,Who was the first to sail around the earth.

Why we do not fall from the Earth ?

Gravity is the force of the Earth that attracts every object toward itself. From our perspective this force always act downwords. For a long time people did not believe that the Earth is round then the people 'underneaath"the sphere would have actually fallen down. In 1687,a physicist issac Newton, prooved that the force of gravity always acts towards the center of the Earth.On the Earth,The force of gravitation always acts 'downwords' irrespect of Eskimos in the Artic region, people in Europe or in habbitants of australa.

What is the atmosphere made up of ?

The word 'atmosphere' means a gaseous cover enveloping a planet. With out atmosphere life would have not been possible on the Earth. One fifth of the atmosphere is Oxygen and four-fifth is Nitrogen. Like the earth interior. The atmosphere too is made up of several layers. All animal and planet lived in the lower most layer of the atmosphere called the troposphere. All weather phenomena take place in the troposphere. Even aeroplanes fly in the outer edge of the troposphere. The stratosphere ,the mesosphere, the iono sphere and the exosphere lie above the traposphere.