Volcanoes

 Volcanoes are scattered across the planet.

About 1,500 active volcanoes can be found across the world though countless others are on the ocean floor. 

Most volcanoes whether on land or underwater are located where tectonic.

Plates meet in fact the ring of fire a path that traces the boundaries between several tectonic plates around the pacific ocean contains about 75% of the planets 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 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.

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

The journey of these emissions begins deep underground in the Earth's core.

The core which can burn as hot as the surface of the sun transfer its heat to the surrounding rocky mantle in doing so 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 in a phenomenon 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 to measure and classify eruptions. 

Scientists developed the volcanic explosivity index or BEI it considers various factors such as the volume of lava gas and other emissions from the volcano along with the height of the eruption.  

Here's a video of me speaking about this.

https://drive.google.com/file/d/1hHdVlCSc90cvAW_BsuC2etjOugtTZTkn/view