Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Formation of the Hawaiian Islands
Document related concepts
no text concepts found
Transcript
Formation of the Hawaiian Islands Volcanoes, Magma, and Hot Spots Topics • Hawai’i • Ring of Fire • Hot Spots • Decompression Melting • The Hawai’i Hot Spot Topics • Hawai’i • Ring of Fire • Hot Spots • Decompression Melting • The Hawai’i Hot Spot Ring of Fire Ring of Fire Volcanoes in the Circum-Pacific Region Definitions Definitions • Magma - molten rock Definitions • Magma - molten rock • Lava - magma that erupts onto the surface Lava Lava • All lava is magma Lava • All lava is magma • But most magma is not lava Lava • All lava is magma • But most magma is not lava • 90% of magma never reaches Earth’s surface and solidifies to rock inside Earth Volcanoes In the Pacific Volcanoes In the Pacific Three primary types of volcanoes in the Pacific Region: Volcanoes In the Pacific Three primary types of volcanoes in the Pacific Region: • Volcanoes at the mid-ocean ridge (MOR) Volcanoes In the Pacific Three primary types of volcanoes in the Pacific Region: • Volcanoes at the mid-ocean ridge (MOR) • Continental and island arc volcanoes in the ring of fire Volcanoes In the Pacific Three primary types of volcanoes in the Pacific Region: • Volcanoes at the mid-ocean ridge (MOR) • Continental and island arc volcanoes in the ring of fire • Hot spot volcanoes Mid-Ocean Ridge East Pacific Rise Ring of Fire Ring of Fire Thousands of volcanoes form near continental margins as continental or island arc volcanoes: Ring of Fire Thousands of volcanoes form near continental margins as continental or island arc volcanoes: • South America • Philippines • Central America • Marianas • North America • New Guinea • Aleutians • Samoa • Russia • Tonga • Japan • New Zealand Island Arc Island Arc Volcano Japan Island Arc Volcano Aleutians Continental Volcano Chile Continental Volcano North America Subduction Subduction • Most of the ring of fire volcanoes are associated with the process of subduction Subduction • Most of the ring of fire volcanoes are associated with the process of subduction • Subduction - process where an oceanic lithospheric plate descends beneath a continental or oceanic plate as the two plates converge Subduction • Most of the ring of fire volcanoes are associated with the process of subduction • Subduction - process where an oceanic lithospheric plate descends beneath a continental or oceanic plate as the two plates converge • Subduction occurs at convergent plate boundaries Magma Generation Magma Generation The exact process of magma generation during subduction is uncertain. However, the most commonly accepted mechanisms are the Magma Generation The exact process of magma generation during subduction is uncertain. However, the most commonly accepted mechanisms are the • Melting of the subducting sediment Magma Generation The exact process of magma generation during subduction is uncertain. However, the most commonly accepted mechanisms are the • Melting of the subducting sediment • Melting of mantle rock as water rises into the hot rock overlying the subducting plate Ri se East Pacific Hot Spots Next Hot Spots
Related documents