Lava is the word for magma when it erupts onto the Earth's surface.
Geologists also use the term to describe the solidified deposits of lava flows
and fragments hurled into the air by explosive eruptions (for example, lava
bombs or blocks). Lava is from the Italian word for stream, which is derived
from the verb lavare—to wash.
Left: A fast-moving lava flow from Mt. Etna in Sicily. Lava
flows can also move slowly, especially as they begin to cool and develop a hard