Understanding Volcanoes : Violent force which shaped the Earth through eons.

Stratovolcanoe Mount Mayon, Philippines

Volcanoes are mysterious portals into the heart of the earth these fiery

 bottomless cauldrons are fueled by hellish magma bubbling and boiling thousands of miles beneath the surface and just waiting to burst through

Volcanoes are scattered across the Earth. A

bout 1500 active volcanoes can be found across the globe, countless others are also located on the ocean floor, quietly waiting to unleash their wrath. Underwater eruptions accompanied with earthquakes can cause massive tsunamis which usually wreaks havoc in coastal human settlements.

Pacific Ring Of Fire & Tectonic Plates

Most volcanoes whether on land or 

underwater are located where tectonic plates meet, in fact the Ring of Fire which marks the boundary between several tectonic plates around the Pacific Ocean contains about 75% of the planet's volcanoes. There are several types of volcanoes primarily classified by shape and size, major types include Stratovolcanoes which often appear as tall steep mountains, Shield volcanoes which are flatter and dome shaped calderas which are large depressions in the ground and mid-ocean ridges which are underwater chains of volcanic mountains.

Structure of volcano (Image Credit : H'arnet)

No matter their shape or size all volcanoes emit gas and molten rock. Th

e journey of these emissions begins deep underground in the Earth's core, The core which burns as hot as the surface of the Sun transfers its heat to the surrounding rocky mantle, the heat melts some of the rock this molten rock or magma is lighter than the surrounding solid rock layer so it rises through the mantle. The magma then escapes through vents in the Earth's crust causing volcanic eruptions.

Now above-ground this magma is referred 

to as lava and it can reach temperatures of over 2,000 degrees Fahrenheit, in addition to lava volcanoes may erupt with searing hot gas formed in the mantle this phenomenon is called pyroclastic flow. This gas combined with hot ash can race down the sides of a volcano as fast as 100 miles per hour burning everything in its path.

VEI balls eruptions scale ( Credit : Geology.com)

To measure and classify eruptions 

scientists developed the volcanic explosivity index or VEI it considers various factors such as the volume of lava gas and other emissions from the volcano along with the height of the eruption cloud above the volcano's summit. The VEI scale begins at zero each successive measurement increases logarithmically, meaning that each magnitude is 10 times more powerful than the one before it. The VEI scale does not have an upper limit but the most catastrophic eruptions measured thus far are categorized as VEI 8. These eruptions occurred thousands and millions of years ago. 

Mount Tambora Ash fall (Credit : Woudloper)

The most destructive volcanic eruption ever witnessed occurred in 

Indonesia. In 1815 Mount Tambora a large stratovolcano erupted with a VEI measurement of 7. The blast caused earthquakes tsunamis and pyroclastic flows that decimated the land and took tens of thousands of Indonesian lives. The eruption even destroyed the top of Mount Tambora itself turning the 13,000 foot tall mountain into a three thousand six hundred and forty foot deep caldera.

While volcanoes are some of the most 

destructive forces of nature they have also helped make life on Earth possible. Volcanic ash provides nutrients to nearby soil making the land fertile and lava when it cools hardens into rock and creates new landforms

With heat from the heart of the earth 

volcanoes have helped transform the planet, making it the rich dynamic landscape we see today.