Magma vs. Lava: What's the Difference?
Read the comparison below, or explore it visually. Create a visual lesson comparing magma and lava using available credits or plan allowance.
Magma is molten rock that is still beneath Earth's surface, while lava is magma that has erupted onto the surface. The material is essentially the same, but location changes its behaviour: underground, magma holds dissolved gases under pressure and cools slowly, while lava loses much of that gas and cools quickly in air or water, forming different kinds of rock.
At a glance
| Magma | Lava | |
|---|---|---|
| Location | Below the surface, in magma chambers | On the surface, after an eruption |
| Dissolved gas | Holds water vapour and CO2 under pressure | Much of the gas escapes into the air |
| Cooling speed | Slow, over thousands of years or more | Fast, from hours to years |
| Rock formed | Intrusive igneous rock, e.g. granite | Extrusive igneous rock, e.g. basalt |
| Crystal size | Large, visible crystals | Tiny crystals or glass, e.g. obsidian |
Which should you use?
Say "magma" for molten rock that has not reached the surface, such as melt that stays trapped kilometres below ground and slowly cools into coarse-grained granite.
Say "lava" once the melt flows out at the surface, as in the vast basalt flows that built the Deccan Traps or eruptions at Barren Island in the Andaman Sea.