Week 1 - Volcanoes (Science)

• Volcanoes are openings or fissures in the Earth's crust through which lava, ash, rock and gases erupt.
• Volcanoes are also mountains formed by the accumulation of these eruptive products.
• At divergent plate boundaries, hot mantle rock rises into the space where the plates are moving apart, lowering the melting temperature of the rock and causing lava to erupt through long cracks in the ground, or fissures.
• Divergence of oceanic plates formed ridges or mountain ranges on the ocean floor, and many undersea volcanoes, or seamounts, are formed by divergence of oceanic plates.
• The mid-ocean ridge is a continuous range of undersea volcanic mountains that encircles the globe almost entirely underwater, accounting for more than 75% of all volcanic activity on the planet.
• Volcanoes are located on Divergent Plates.
• Askja is a volcano located in Iceland.
• Divergent Plates are located in the Pacific Ocean.
• Pavlof is a volcano located in Alaska, USA.
• Examples of divergent plate boundary volcanoes include Davidson Seamount located off the coast of Central California, 80 mi (129 km) southwest of Monterey and 75 mi (121 km) west of San Simeon, Sedlo Seamount located 300 km NE of Graciosa Island, and Bear seamount located about 200 miles (320 km) from Woods Hole, Massachusetts.
• Laki is a volcano located in Iceland.
• Hverfjall is a volcano located in Iceland.
• Kilauea is a volcano located in Hawaii, USA.
• Cerro Azul is a volcano located in Mexico.
• Papatua is a volcano located in American Samoa.
• Wolf volcano is a volcano located in Mexico.
• Sierra Negra is a volcano located in Mexico.
• Mt Baker is a volcano located in the USA.
• Mt Adam is a volcano located in the USA.
• Hotspot volcanoes are located on Convergent Plates.
• Tutuila is a volcano located in American Samoa.
• Mount Nyiragongo is a volcano located in the Democratic Republic of the Congo.
• Mount Kilimanjaro is a volcano located in Tanzania.
• Malulu is a volcano located in American Samoa.
• Mount Pinatubo is a volcano located in the Philippines.
• Mt Mayon is a volcano located in the Philippines.
• Mauna Loa is a volcano located in Hawaii, USA.
• Mt Fujiyama is a volcano located in Japan.
• Rift volcanoes form when magma rises into the gap between diverging plates, occurring at or near diverging plate boundaries.
• Mount Gahinga is a volcano located in Tanzania.
• Examples of Oceanic Island Arcs include the Indonesian Island Arc, Philippine Island Arc, Japanese Island Arc, Aleutian Islands Arc, Solomon Islands, Tonga Islands, Mariana Islands, and Ryukyu Islands.
• A continuous upward movement of magma creates a chain of volcanic islands which are collectively called as Oceanic Island Arcs.
• The formation of volcanoes by Ocean-Continent Convergence involves the denser oceanic plate subducting below the less dense continental plate, after which the subducting plates melt, forming magma.
• Volcanoes can also be formed by Divergent Plate Convergence, where magma rises up from the Earth's mantle due to heat, forming volcanoes.
• These so-called “hotspot” volcanoes are created when a narrow stream of hot mantle rises up from deep inside the earth and melts a hole in the plate so that the magma can ooze upward.
• The magma rises upwards due to the buoyant force offered by surrounding denser medium and flows out to the surface.
• Examples of Divergent Plate Convergence volcanoes include Mount Mayon, Mount Baker, Mauna Kea, Dominica, Mount Katmai, Mount Ayalu, Mount Fuji, Formica, Leo, Dallafilla, Tutuila, El Misti, Paka, Dabbahu.
• As the plates move, the hot spot does not, and may create a chain of volcanoes on the Earth's surface.
• Examples of hotspot volcanoes include the Hawaiian Islands, Samoan Islands, and Yellowstone hotspots.
• Examples of rift volcanoes include Mount Kilimanjaro in Tanzania, Mount Nyiragongo in the Democratic Republic of Congo, Erta Ale in Ethiopia, Dalafilla in Ethiopia, Ol Doinyo Lengai in Ethiopia, and Paka in Kenya.