what type of volcano are formed at underwater lava build up gradually
Shield volcanoes are formed when a large amount of free-flowing lava spills from a vent and spreads widely. The lava gradually builds up a low, broad dome shaped mountain. The famous Mauna Loa in Hawaii is a shield volcano.Thousands of separate, over lapping lava flows, each less then 50 ft thick, formed Mauna Loa.This picture demonstrates the shield volcano.he lava gradually builds up a low, broad dome shaped mountain. The famous Mauna Loa in Hawaii is a shield volcano. Thousands of separate, over lapping lava flows, each less then 50 ft thick, formed Mauna Loa. This picture demonstrates the shield volcano.