Geology what is the difference between magma and lava

Magma is a mixture of molten and semi-molten rock found beneath the surface of the Earth. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Image lava flow Lava magma that has erupted onto the Earth's surface is visually mesmerizing — as the molten rock flows downhill, lava exposed to the air cools to a deep black color, while the molten rock beneath glows bright orange.

Photograph by Budkov Denis. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.

Media If a media asset is downloadable, a download button appears in the corner of the media viewer. Text Text on this page is printable and can be used according to our Terms of Service. Interactives Any interactives on this page can only be played while you are visiting our website.

Related Resources. View Collection. Magma's Role in the Rock Cycle. View Article. Magma on Hawaiian Coast. View Photograph. They are both molten rock, and are both associated with volcanism.

So why the separate names? As it turns out, it all comes down to location. As anyone with a basic knowledge of geology will tell you, the insides of the Earth are very hot. As a terrestrial planet , its interior is differentiated between a molten, metal core, and a mantle and crust composed primarily of silicate rock. Life as we know it, consisting of all vegetation and land animals, live on the cool crust, whereas sea life inhabits the oceans that cover a large extent of this same crust.

However, the deeper one goes into the planet, both pressures and temperatures increase considerably. Although solid, the high temperatures within the mantle cause pockets of molten rock to form.

This silicate material is less dense than the surrounding rock, and is therefore sufficiently ductile that it can flow on very long timescales. Over time, it will also reach the surface as geological forces push it upwards. This happens as a result of tectonic activity. Basically, the cool, rigid crust is broken into pieces called tectonic plates. These plates are rigid segments that move in relation to one another at one of three types of plate boundaries. These are known as convergent boundaries, at which two plates come together; divergent boundaries, at which two plates are pulled apart; and transform boundaries, in which two plates slide past one another laterally.

As the tectonic plates migrate across the planet, the ocean floor is subducted — the leading edge of one plate pushing under another. At the same time, mantle material will push up at divergent boundaries, forcing molten rock to the surface. However, if it starts to rise, it encounters lower and lower temperatures, where it may start to solidify — and it often does, even before it reaches the surface.

What is different however is that magma generally sits in hot chambers, and when it reaches the surface and becomes lava , it quickly solidifies due to the much lower temperatures. Technically, lava is any molten rock expelled by a volcano in any way. But the rocks formed immediately through cooling is also called lava, which can be a little bit confusing.

Most often though, we refer to lava as a singular flow or eruption. Join the ZME newsletter for amazing science news, features, and exclusive scoops. More than 40, subscribers can't be wrong. There are several types of lava, depending on the chemical composition, temperature, and other particularities, but describing them goes beyond the purpose of this article.

Just like magma, it is made up of crystals , volcanic glass, and bubbles volcanic gasses.