How Do Volcanoes Erupt?
A volcano is one of the most interesting and exciting features of the planet but is also one of the most dangerous. Just recently one of the world most dangerous volcanoes erupted causing massive destruction is Hawaii. So, how do volcanoes erupt?
To put it simply volcanoes are openings in the earth’s crust, usually in mountains, where magma can escape. They open downwards to a pool of molten rock below the surface of the earth. Most volcanoes are pictured as cone shaped mountains when really, any crack in the earth’s surface from which magma can escape from is a volcano.
Volcanoes erupt when cracks form in the Earth’s crust allowing magma to escape. The Earth is made up of four main layers: the inner core, the outer core, the mantle and the crust. The core is the very centre of the earth and is extremely hot. The mantle is just above the core where magma and hot ash is stored and the crust is the surface of the earth.
The Earth’s crust is made up of huge slabs called plates which move extremely slowly, I’m talking a couple millimetres a year people, but when heat and pressure build up from the Earth’s mantle, the plate’s crash forming cracks in the earth’s crust where magma can escape. This scientific theory is called plate tectonic.
Once a volcano has erupted and magma is spewed out, it is known as lava. When a volcano erupts there usually is lava flow and eventually it will get bigger and bigger. Over time the molten rock and lava solidify creating that volcano mountain shape.
Magma is hot molten or liquefied rock stored deep below the earth’s crust in the lower mantle. There is no real difference between lava and magma. Lava is just a form of magma that has erupted from a volcano or fissure and is on the surface of the earth while magma is below. Lava is seen as a bright scarlet that is thick and over 400℃.
Most rocks melting temperature of different minerals and though most rocks melting temperature is mostly 700°c each mineral has a different melting temperature so lava is able to partially melt the rocks on the volcanoes side but not completely.
|The city was buried in ash. As people were sleeping they were turned to stone.
|This volcano destroyed an entire city!
The most dangerous volcano is believed to be Mount Vesuvius. Mount Vesuvius is most famous for the A.D. 79 eruption that buried the cities of Pompeii and Herculaneum. Despite the dark history, millions of people today live near the volcano. The thriving mass of humanity in such close proximity to the volcano makes Vesuvius a serious contender for the world’s most dangerous volcano. Scientists fear that a catastrophic eruption could hurl scalding gas-rich magma, water vapour and debris at the masses with insufficient warning time for an evacuation.
|The world’s largest active volcano is Mauna Loa in Hawaii standing at 4,169m! Some geologists also believe that Tamu Massif is also the largest volcano which is standing at about 6,500 feet (about 2,000 meters). It is below ocean surface, while the base extends down to about 4 miles (6.4 kilometres) deep.
So basically, volcanoes are caused by pressure creating cracks in the crust so magma can escape. They are fascinating but dangerous. Some people live near active ones! And some are erupting right now!
|Tamu Massif dwarfs the largest active volcano in the sea!
Debris: scattered pieces of rubbish or remains.
Fissure: a long, narrow opening or line of breakage usually in rock or in the earth.
Herculaneum: Located in the shadow of Mount Vesuvius, Herculaneum was an ancient Roman town destroyed by the volcano.
Lava: hot molten or semi-fluid rock erupted from a volcano or fissure.
Magma: hot fluid or semi-fluid material below or within the earth’s crust.
Mauna Loa: the largest volcano/mountain on earth!
Molten Rock: Molten rock refers to rock that has been melted.
Mount Vesuvius: Mount Vesuvius is an active volcano in southern Italy. It is famous for an eruption that happened in ad 79. Thousands of people died when lava, ashes, and mud buried the cities of Pompeii, Herculaneum, and Stabiae. The cities were forgotten until archaeologists began digging up their ruins in the 1700s.It is the most dangerous volcano.
Plate tectonics: The theory, or idea, of plate tectonics says that Earth’s outer layer is made up of large, moving pieces called plates. All of Earth’s land and water sit on these plates. The plates are made of solid rock. Under the plates is a weaker layer of partially melted rock.
Pompeii: On August 24, 79 CE, the volcano Vesuvius in southern Italy erupted. A thick cloud of ash, stone, and poisonous gas rained down on the Roman town of Pompeii, which stood in the path of the eruption. The town was completely buried in just a few hours.
Tamu Massif: Tamu Massif is an extinct submarine shield volcano located in the north western Pacific Ocean. The possibility of its nature as a single volcano was announced on 5 September 2013.