GEOLOGY

Detailed explanation-1: -Most shield volcano eruptions are nonexplosive (effusive), usually 0-1 on the Volcanic Explosivity Index (VEI), typically in the Hawaiian eruptive style. These eruptions produce fluid lava flows and may produce fire-fountains. High rates of eruptions help produce lava flows that travel fast and can cover large areas.

Detailed explanation-2: -Most shield volcanoes are formed from fluid, basaltic lava flows. Mauna Kea and Mauna Loa are shield volcanoes. They are the world’s largest active volcanoes, rising over 9 km above the sea floor around the island of Hawai’i.

Detailed explanation-3: -Shield volcanoes thus form by relatively non-explosive eruptions of low viscosity basaltic magma.

Detailed explanation-4: -Shield volcanoes are more common at spreading centers or volcanic hot spots in the middle of tectonic plates (Figure 8.24). The magma that creates shield volcanoes is less viscous, so it flows much more easily. For this reason, the eruptions of shield volcanoes are non-explosive.

Detailed explanation-5: -Shield volcanoes usually have quiet eruptions, with lava flows that spread before they cool to make basalt layers.