1. Garrett Apuzen-Ito Professor of Geophysics Department of Geology & Geophysics SOEST, University of Hawaii-Manoa I. Our Dynamic Earth Expressed through the Creation of the Philippine Archipelago Objectives: 1) Overview plate tectonics & Earth’s major forms of volcanism 2) Summarize origin & evolution of the Philippine Archipelago

2. Plate Tectonics The rigid outer shell of the Earth, called the lithosphere, is broken up into many rigid segments of different sizes and shapes.

3. Pangaea (240 Myr ago) First evident in the continent jigsaw puzzle Present Day Plate Tectonics

5. Plate Tectonics is the Surface Expression of Mantle Convection Hot (~3000 o F), Ductile but (mostly) solid Upper mantle seafloor spreading subduction

6. How Fast Do the Plates Move? seafloor spreading subduction Sloooowly: 1-10 cm/yr

7. That’s about 100 Million yrs! How Long Did it Take to Create the Pacific Basin? seafloor spreading subduction 1-10 cm/yr At 10 cm/yr & life time of 100 yrs how much finger nail is grown? 10 m A 1000 human life times gives 10km A 1000 x 1000 human life times gives 10,000km

8. Three Main Origins of Volcanism Mid-ocean ridge volcanism creates the seafloor. 60% of Earth’s surface!

9. Three Main Origins of Volcanism

10. Arc volcanism behind subduction zones. “Pacific Ring of Fire”

11. Tectonic Environment of the Philippines

12. How to Prepare for your Talk 1) Collect and learn your material 2) Decide on your main points 3)Prepare slides that start lead your forward towards your main points 4) Practice (for effect, timing, performance) 5) Adjust your slides appropriately 6) Practice out loud to yourself