An eruption dominated by the outpouring of lava
onto the ground. Lava flows generated by effusive eruptions vary in shape,
thickness, length, and width depending on the type of lava erupted, discharge,
slope of the ground over which the lava travels, and duration of eruption.
An effusive eruption is distinct from the violent fragmentation of magma
by an explosive eruption.
|Basalt lava erupts from Pu'u 'O'o spatter and cinder
cone at Kilauea Volcano, Hawai'i. Lava spilling from the cone
has formed a series of a'a lava channels and flows. Credit: J. D.
Griggs / U.S. Geological Survey
For example, basalt lava may become a'a
or pahohoe, and flow in deep narrow channels
or in thin wide sheets. Andesite lava typically
forms thick stubby flows, and dacite lava
often forms steep-sided mounds called lava domes.
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