A volcano is
an opening in the earth's crust through which lava, volcanic ash, and gases escape
. … Beneath a volcano, liquid magma containing dissolved gases rises through cracks in the Earth's crust. As the magma rises, pressure decreases, allowing the gases to form bubbles.
What is a volcano for Class 7?
An opening in the earth's crust that allows hot molten lava, ash and gases to escape from below the surface
, is called a volcano. … With time, the lava and ash flow out of the magma chamber, cool down, solidify and accumulate in layers forming a 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 a volcano Class 5?
A volcano is
a mountain that opens downward to a pool of molten rock below the surface of the earth
. When pressure builds up, eruptions occur. Gases and rock shoot up through the opening and spill over or fill the air with lava fragments.
What is a volcano Class 6?
A volcano is
a landform, a mountain, where molten rocks erupt through the surface of the planet
. The volcano mountain opens downwards to a pool of molten rocks underneath the surface of the earth. Pressure builds up in the earth's crust and this is the reason why eruptions occur.
What causes volcano?
On land, volcanoes form when
one tectonic plate moves under another
. Usually a thin, heavy oceanic plate subducts, or moves under, a thicker continental plate. … When enough magma builds up in the magma chamber, it forces its way up to the surface and erupts, often causing volcanic eruptions.
What is the oldest volcano?
How old is the oldest volcano? The oldest volcano is probably
Etna
and that is about 350,000 years old. Most of the active volcanoes that we know about seem to be less than 100,000 years old. Volcanoes grow because lava or ash accumulates on the volcano, adding layers and height.
What is volcano explain?
A volcano is
an opening in the earth's crust through which lava, volcanic ash, and gases escape
. … Beneath a volcano, liquid magma containing dissolved gases rises through cracks in the Earth's crust. As the magma rises, pressure decreases, allowing the gases to form bubbles.
What is the structure of volcano?
erupting volcano The main parts of a volcano are 1)
the crater
, a depression at the top of the volcano from which volcanic material has been ejected; 2) the vent, the conduit between crater and the magma; and 3) the cone, the area around the crater at the top of the volcano, made up of material ejected during an …
What is the use of volcano?
“It gives us really fertile soils, which are great for
farming and crops
.” Volcanoes also provide a good environment for the formation of new habitats for animals, plants and insects, she said. Hot springs and geothermal energy are additional benefits.
How many volcanoes are active today?
There are currently
26 active volcanoes
erupting around the world today. According to the U.S. Geological Survey (USGS), there are about 1,500 potentially active volcanoes worldwide, with about 500 of the 1,500 erupting in historical times.
What are the three types of volcano?
There are three types of volcanoes:
cinder cones (also called spatter cones), composite volcanoes (also called stratovolcanoes), and shield volcanoes
. Figure 11.22 illustrates the size and shape differences amongst these volcanoes. Shield volcanoes, which get their name from their broad rounded shape, are the largest.
What is volcanic eruption Class 9?
A volcano is an opening or rupture in the earth's surface that allows magma
(hot liquid and semi-liquid rock), volcanic ash and gases to escape
. They are generally found where tectonic plates come together or separate but they can also occur in the middle of plates due to volcanic hotspots.
What are effects of volcano?
Volcanoes spew
hot, dangerous gases, ash, lava, and rock
that are powerfully destructive. People have died from volcanic blasts. Volcanic eruptions can result in additional threats to health, such as floods, mudslides, power outages, drinking water contamination, and wildfires.
When volcano Erupts what happens?
A volcano is a vent in the Earth's crust from which eruptions occur. … When volcanoes erupt they
can spew hot, dangerous gases, ash, lava and rock that can cause disastrous loss of life and property
, especially in heavily populated areas.
