Effusive volcanism and plate tectonics
People associate volcanoes with spectacular explosive eruptions, yet most volcanoes erupt basalt, a fluid lava from the mantle that erupts effusively and forms flows. Most basaltic lava erupts on the ocean floor, along an undersea mountain chain called the mid-ocean ridge system. Basaltic lava also erupts at “hot spots,” where molten rock, or magma, forms in plumes of hot rock that rise from deep in the Earth to penetrate a moving plate above. Over time, a chain of volcanoes forms, such as the Hawaiian Islands, aligned along the direction of the plate’s movement.
Topic: Earth Science
Keywords: Volcanoes, Basalt, Plate tectonics, Lava, Volcanism, Volcanic eruptions
A chain of 107 volcanoes – some islands, some submerged – extends from Hawaii to the northwest.
In 1983, lava flows from the Kilauea volcano began to encroach upon the Royal Gardens area on the island of Hawaii.
Magma is molten rock.
The longest volcano chain in the world is the 80,000-kilometer-long mid-ocean ridge system, where new ocean crust is formed and the tectonic plates - the Earth's moving outer shell - separate from each other.
Among the major outpourings of lava are the huge plains known as flood basalt provinces.