Shield volcano

A shield volcano is a type of volcano usually built almost entirely of fluid magma flows. They are named for their large size and low profile, resembling a warrior's shield lying on the ground. This is caused by the highly fluid lava they erupt, which travels farther than lava erupted from stratovolcanoes. This results in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form. The shape of shield volcanoes is due to the low-viscosity magma of their mafic lava.

Etymology

Shield volcanoes are built by effusive eruptions, which flow out in all directions to create a shield like that of a warrior. The word "shield" has a long history, and is derived from the Old English scield or scild, which is in turn taken from the Proto-Germanic *skelduz, and related to the Gothic skildus, meaning "to divide, split, or separate". Shield volcano itself is taken from the German term Schildvulkan.

Geology

Structure