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Garrett Apuzen-Ito Professor of Geophysics Department of Geology & Geophysics SOEST, University of Hawaii-Manoa. Objectives: 1) Overview plate tectonics & Earth’s major forms of volcanism 2) Summarize origin & evolution of the Philippine Archipelago.
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Garrett Apuzen-ItoProfessor of Geophysics Department of Geology & Geophysics SOEST, University of Hawaii-Manoa Objectives: 1) Overview plate tectonics & Earth’s major forms of volcanism 2) Summarize origin & evolution of the Philippine Archipelago • I. Our Dynamic Earth Expressed through the Creation of the Philippine Archipelago
Plate Tectonics The rigid outer shell of the Earth, called the lithosphere, is broken up into many rigid segments of different sizes and shapes.
Plate Tectonics First evident in the continent jigsaw puzzle Pangaea (240 Myr ago) Present Day
Types of Plate Boundaries Convergent Divergent Transform
Plate Tectonics is the Surface Expression of Mantle Convection Upper mantle Hot (~3000 oF), Ductile but (mostly) solid seafloor spreading subduction subduction
How Fast Do the Plates Move? seafloor spreading Sloooowly: 1-10 cm/yr subduction subduction
How Long Did it Take to Create the Pacific Basin? seafloor spreading That’s about 100 Million yrs! 1-10 cm/yr A 1000 human life times gives 10km At 10 cm/yr & life time of 100 yrs how much finger nail is grown? A 1000 x 1000 human life times gives 10,000km subduction subduction 10 m
Three Main Origins of Volcanism Mid-ocean ridge volcanism creates the seafloor. 60% of Earth’s surface!
Three Main Origins of Volcanism Arc volcanism behind subduction zones. “Pacific Ring of Fire”
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