What is a volcano and how is it formed?

A volcano is formed when hot molten rock, ash and gases escape from an opening in the Earth’s surface. The molten rock and ash solidify as they cool, forming the distinctive volcano shape shown here. As a volcano erupts, it spills lava that flows downslope. Hot ash and gases are thrown into the air.

What is volcano explain?

Volcanoes are openings, or vents where lava, tephra (small rocks), and steam erupt on to the Earth’s surface.

What causes volcano to form?

Volcanoes are formed by eruptions of lava and ash when magma rises through cracks or weak-spots in the Earth’s crust. A build up of pressure in the earth is released, by things such as a plate movement which forces molten rock to exploded into the air causing a volcanic eruption.

How are volcanoes formed for kids?

A volcano is formed when hot molten rock, ash and gases escape from an opening in the Earth’s surface. The molten rock and ash solidify as they cool, forming the distinctive volcano shape shown here. As a volcano erupts, it spills lava that flows downslope. Hot ash and gases are thrown into the air.

How is lava formed in a volcano?

Extremely high temperature and pressure cause the rock to melt and become liquid rock or magma. When a large body of magma has formed, it rises thorugh the denser rock layers toward Earth’s surface. Magma that has reached the surface is called lava.

How do volcanoes formed what are its two main process?

Volcanoes form here in two settings where either oceanic plate descends below another oceanic plate or an oceanic plate descends below a continental plate. This process is called subduction and creates distinctive types of volcanoes depending on the setting: ocean-ocean subduction produces an island-arc volcano.

What is a volcano for kids?

A volcano is a mountain or hill with an opening. When a volcano erupts, magma is pushed up through the opening with great force. When magma reaches the Earth’s surface, it is called lava. Lava can be as hot as 2,200°F (1,204°C). Some volcanic eruptions are explosive.

What is inside a volcano?

Inside an active volcano is a chamber in which molten rock, called magma, collects. Pressure builds up inside the magma chamber, causing the magma to move through channels in the rock and escape onto the planet’s surface. Once it flows onto the surface the magma is known as lava.

What are the 3 types of volcanoes?

The Three Classic Types of Volcanoes

• Cinder Cone Volcanoes.
• Composite Volcanoes (Stratovolcanoes)
• Shield Volcanoes.

What is the mouth of the volcano?

Crater

Crater – Mouth of a volcano – surrounds a volcanic vent.

How deep is a volcano?

Most of these volcanoes are thousands of feet deep, and difficult to find. But in May of 2009, scientists captured the deepest ocean eruption ever found. Nearly 4000 feet below the surface of the Pacific Ocean – in an area between Samoa, Fiji and Tonga – the West Mata volcano was discovered.

Why is lava so hot?

Lava is hot for two primary reasons: Pressure and radiogenic heating make it very hot deep in the Earth (about 100 km down) where rocks melt to make magma. The rock around the magma is a good insulator so the magma doesn’t lose much heat on the way to the surface.

How hot is it inside a volcano?

The liquid rock that forms a volcano is called either magma or lava. Magma is the liquid rock found inside a volcano and can range in temperature from 700 to 1,300 degrees Celsius, while it is called lava once it has erupted from the volcano.

Are volcanoes underwater?

It was also a chance discovery. More than 70 percent of all volcanic eruptions occur underwater and scientists are in the dark when it comes to understanding underwater volcanoes because the eruptions are cloaked from view by thousands of feet of water.

How many volcanoes are in the ocean?

Only 119 submarine volcanoes in Earth’s oceans and seas are known to have erupted during the last 11,700 years. Hydrothermal vents, sites of abundant biological activity, are commonly found near submarine volcanoes.

What happens when lava hits salt water?

When lava comes into contact with ocean water, it produces a gas plume known as laze – lava and haze. Laze forms through a series of chemical reactions as hot lava boils the colder sea water.

What happens when lava meets the ocean?

Since heat is exchanged at the interface between lava and seawater, processes that increase the surface area of lava exposed to seawater increase steam formation. High lava-flow rates produce more heated surface area. When an active bench collapses, large surfaces of hot material are suddenly exposed to seawater.

What is cold lava?

Cold lava flows, also known as lahars, are mud flows consisting of volcanic ash, rocks and other debris. The flows can travel quickly and effectively bulldoze or bury anything in their paths.

Can water stop a volcano?

There’s no way to stop lava. Once fissures open and the hot stuff starts flowing, it’s best not to fight nature. “The flows cannot be stopped, but people have tried in the past,” said Benjamin Andrews, director of the Global Volcanism Program at the Smithsonian National Museum of Natural History.

What happens when lava hits ice?

When lava meets ice, it neither explodes nor tunnels through; rather, it forms strange-looking bubbles. These bubbles are initially the same color as lava, but quickly turn black. One of the experimenters called these bubbles “scrambled eggs from hell”.

Can a diamond melt in lava?

To put it simply, a diamond cannot melt in lava, because the melting point of a diamond is around 4500 °C (at a pressure of 100 kilobars) and lava can only be as hot as about 1200 °C.

Can you freeze lava?

Magma and lava solidify in much the same way that water freezes. When magma or lava cools down enough, it solidi- fies, or “freezes,” to form igneous rock. One difference between water freezing and magma freezing is that water freezes at 0°C and magma and lava freeze at between 700°C and 1,250°C.

Can snow stop lava?

Results show that if ice or snow is covered by volcanic ash at the start of an eruption, this will significantly slow the rate of melting if lava flows later move over the ash-covered ice.

Why is hot lava red?

Simply put, because it’s hot – in fact, lava can reach up to 1,250 degrees Celsius (2,282 degrees Fahrenheit). Heat excites atoms, which can boost atoms’ electrons to higher orbitals. When an excited electron returns to its normal orbital, it releases its excess energy as a light photon.

Does Obsidian exist?

obsidian, igneous rock occurring as a natural glass formed by the rapid cooling of viscous lava from volcanoes. Obsidian is extremely rich in silica (about 65 to 80 percent), is low in water, and has a chemical composition similar to rhyolite. Obsidian has a glassy lustre and is slightly harder than window glass.