Lava flows are masses of magma that pour onto the Earth's surface during an
effusive eruption; they include both moving lava and the resulting
solidified deposits. Lava flows come in a great variety of shapes and sizes.
This is due to the wide range in lava discharge during eruptions,
characteristics of the erupting vent and topography over which lava travels,
and viscosity of the different lava types.
Left: A molten river of lava runs through the Valle del
Bove during an eruption by Mount Etna in Sicily.