Customize Consent Preferences

We use cookies to help you navigate efficiently and perform certain functions. You will find detailed information about all cookies under each consent category below.

The cookies that are categorized as "Necessary" are stored on your browser as they are essential for enabling the basic functionalities of the site. ... 

Always Active

Necessary cookies are required to enable the basic features of this site, such as providing secure log-in or adjusting your consent preferences. These cookies do not store any personally identifiable data.

No cookies to display.

Functional cookies help perform certain functionalities like sharing the content of the website on social media platforms, collecting feedback, and other third-party features.

No cookies to display.

Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics such as the number of visitors, bounce rate, traffic source, etc.

No cookies to display.

Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.

No cookies to display.

Advertisement cookies are used to provide visitors with customized advertisements based on the pages you visited previously and to analyze the effectiveness of the ad campaigns.

No cookies to display.

Empowering you to understand your world

How Volcanoes Work

A volcano is a vent in the earth which gases and molten rock (melted rock, otherwise known as magma) are forced through up onto the surface of the earth, due to high pressure.

Magma is molten rock below the surface of the earth, and lava is what magma is called after it erupts onto (above) the surface of the earth. The terms below and above are bold to emphasize the importance of the molten rock’s location.

A volcano. Image obtained with thanks from johncooke on Flickr.

The volcanic mountains observed (which people usually refer to as volcanoes) are actually cooled lava and ash which came from past eruptions. Lava becomes solid rock when cooled. Lava is molten (melted) rock.

Over extended time periods, each successive eruption deposits more lava on top of the existing rock, and then it cools as well. So with each eruption, another layer of rock is deposited on top of the old one and cools until a mountain is formed.

Simply put: Lava keeps flowing out, cools to become solid rock, and then that same process is repeated later on top of that rock until it becomes a mountain.

Lava in Hrunagil. Obtained with thanks from Met Office on Flickr.
This is a volcano in Bali, which is in Indonesia. Obtained with thanks from pinkanna1980 on Flickr.
Lightning at the Chaiten volcano in Chile (caused by the volcanic ash cloud). Image obtained with thanks from fmg2001 on Flickr.

Volcanic Hazards

There are multiple volcanic hazards, some of which may surprise you, such as:

  • Volcanic Ash: This consists of very hard and abrasive fragments of volcanic glass, minerals, and rock which can cause lung cancer and choking. These fragments are less than 2mm in diameter. As you would expect, the smallest ash particles travel and fall the furthest distance from the erupting volcano, and the largest ones fall nearest to the volcano due to their heavier weight. Source.
  • Sulfur Dioxide (SO2) and Carbon Monoxide (CO): These substances are highly toxic.
  • Lava: Lava is 700 (1,292 °F)  to 1,600 °C (2,912 °F) [Source]. It is therefore hot enough to kill you if you get your foot stuck in it, for example. Large scale lava flows can wipe out an entire village, not only because it will burn it, but it is also extremely heavy and viscous (dense and syrupy).

Read more

Leave a Reply

Subscribe to our newsletter
Get notified when new content is published