magma
n. uncountablen. extremely hot, liquid rock that is still under the ground. When it comes out of a volcano, it is called lava.
n. molten or semi-molten rock material located beneath the Earth's surface, from which igneous rocks are formed by cooling. Distinguished from lava by its subterranean location.
Magma flows deep beneath the surface of the volcano.
Geologists use seismic waves to map the movement of magma within the chamber before an eruption occurs.
The chemical composition of the magma determines the viscosity of the eventual flow, with silica-rich mixtures resulting in more explosive volcanic events.
Etymology tree Proto-Indo-European *mh₂ǵyéti Ancient Greek μάσσω (mássō) Proto-Indo-European *-mn̥ Ancient Greek -μα (-ma) Ancient Greek μάγμα (mágma)der. English magma From Ancient Greek μάγμα (mágma, “paste”).
Uncountable when referring to the substance; can be countable when referring to specific geological types or chemical compositions.