A distant volcano glowing with lava under a dramatic sky.

Big question

为什么火山会喷发？

Wèishénme huǒshān huì pēnfā?

Why do volcanoes erupt?

火山会喷发，是因为地底下很热的岩浆和气体越积越多，最后把自己往外推出来。

Huǒshān huì pēnfā, shì yīnwèi dìdǐ xià hěn rè de yánjiāng hé qìtǐ yuè jī yuè duō, zuìhòu bǎ zìjǐ wǎng wài tuī chūlái.

在地球很深很深的里面，有些石头热到会融化，变成岩浆。有时候，这些很热的岩浆和被困住的气体会在地下聚在一起。如果压力变得很大，它们就可能冲出来，从火山口喷出熔岩、火山灰和烟。

Zài dìqiú hěn shēn hěn shēn de lǐmiàn, yǒuxiē shítou rè dào huì rónghuà, biànchéng yánjiāng. Yǒu shíhou, zhèxiē hěn rè de yánjiāng hé bèi kùnzhù de qìtǐ huì zài dìxià jù zài yìqǐ. Rúguǒ yālì biàn de hěn dà, tāmen jiù kěnéng chōng chūlái, cóng huǒshānkǒu pēn chū róngyán, huǒshānhuī hé yān.

如果你在很远很安全的地方看火山，你觉得自己会看到什么颜色呢？

Rúguǒ nǐ zài hěn yuǎn hěn ānquán de dìfang kàn huǒshān, nǐ juéde zìjǐ huì kàndào shénme yánsè ne?

Volcanoes erupt when hot melted rock and gas build up pressure under Earth's surface and push their way out.

Deep inside Earth, some rock is so hot that it melts and turns into magma. Sometimes that hot magma and trapped gas gather under the ground. If the pressure gets strong enough, it can break through and come out as lava, ash, and smoke from a volcano.

What colors do you imagine you might see if you watched a volcano from very far away and very safely?