The Conversation

  • Written by Richard John Arculus, Emeritus professor in geology, Australian National University

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

Does lava from an erupting volcano melt everything in its path? And why does lava not melt the sides of the volcano itself? - Liam, age 5, Ashwood.

Thank you, Liam, for asking these very interesting questions. I can see you are starting to think like a scientist.

The short answer is that while lava is hot, it’s not hot enough to melt the rocks on the side of or surrounding the volcano.

Most rocks have melting points higher than 700℃. Lava is between 700℃ and 1200℃ when it erupts but starts to cool as it slides down the side of the volcano. The air and the ground help cool it down. You only need 100℃ to boil water, so this is very, very hot.

So by the time it’s out of the volcano, lava is generally not quite hot enough to melt the rocks it flows over.

But lava flows can set fire to grass, bushes, and trees. And sometimes if houses are in the way, the lava flow will set fire to the wood that is in the houses. All that is left of the house is ash.

Most people in Australia don’t get to see lava - but if you do, it’ll be the hottest stuff you ever see in your life.

There is only one volcano in Australia where you can see lava. It’s called Big Ben. It is on Heard Island, a very long way west of Australia in the Indian Ocean.

Read more: Curious Kids: Why don't the planets closest to the Sun melt or burn up?

Here’s a video of a scientist collecting some lava:

Scientists collect lava from a volcano.

Read more: Curious Kids: Do most volcanologists die from getting too close to volcanoes?

The lava from the Big Ben volcano flows down the sides of a mountain covered in snow and ice. And the lava melts the ice, which makes water. When the lava touches the water, it makes steam and explodes.

Here’s a photo I took of Big Ben erupting, during an expedition in early 2016:

Curious Kids: why doesn't lava melt the side of the volcano? Big Ben is on Heard Island. Richard Arculus, CC BY

There are lots of places in Australia where old lava flows can be seen. These are now quite cool and it is safe to touch them.

They were flowing a very long time ago. You can visit old lava flows in Western Australia near the southwest coast at Bunbury, around Mount Gambier in South Australia, near Mount Leura in Victoria, along the northwest coast at Stanley in Tasmania, around Cooma in NSW, and at Undara in Queensland.

The First Australians would have seen some of these lava flows coming out of volcanoes and flowing over the ground. That must have been an amazing sight.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au * Tell us on Twitter by tagging @ConversationEDU with the hashtag #curiouskids, or * Tell us on Facebook

Curious Kids: why doesn't lava melt the side of the volcano? CC BY-ND Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Authors: Richard John Arculus, Emeritus professor in geology, Australian National University

Read more http://theconversation.com/curious-kids-why-doesnt-lava-melt-the-side-of-the-volcano-90683


George Neophytou Like a National Unleashed

George Neophytou has pledged to support all promises that the Coalition have made to benefit Gippsland East including funding for Bairnsdale Secondary College, funding for text books, more funding f...

George Neophytou - Don’t be taken for granted

George Neophytou George Neophytou, independent candidate for Gippsland East is concerned our electorate is being taken for granted. For too long Gippsland East has been the electorate that Labor...

Prime Minister's media conference at Glenelg


Business News

5 ways to boost employee engagement with video

The two biggest challenges facing HR this year are employee engagement (41%) and retention (35%).  It’s not hard to see why, when some companies value profit over people. Low employee engagement of...

Brava Lingerie

Brava Lingerie’s Customer Service The Perfect Fit; 2018 eftpos ARA Australian Retail Awards winners When Lin Windram and daughter Maxine launched Brava Lingerie 12 years ago due to their own negati...

Australian handmade soaps woo China buyers

Natural handmade soaps are experiencing a boom across mainland China with households prepared to pay a premium to buy them.    Driven by a growing disillusionment with cosmetics products that contai...


The Best Moment of Your Life from Lonely Planet

Discover 100 Life-Changing Travel Experiences with The Best Moment of Your Life from Lonely Planet What’s the best moment of your life? It’s a simple question to ask, but a more challenging one t...

Travel expert Anthony Goldman outlines what's trending for elite travellers

LOVERS OF LUXE DRIVING TRAVEL TRENDS   Travel expert Anthony Goldman outlines what’s trending for elite travellers in 2019 and beyond…   Media Release – 15 October 2018 - Travellers are splurgin...

End of year travel can deliver big benefits if booked on certain credit cards

With more than 56% percent of the Australian population now owning a passport, it is no surprise the Australia Government recorded over nine million trips overseas at 2017 financial year end.   A wh...