Geology of Costa Rica

1. Geology of Costa Rica

2. Geologic Hazards • Earthquakes • Tsunami • Volcanism • Slope Hazards

3. Earthquake Safety • You may well experience an earthquake • Earthquakes don’t kill people; Buildings kill people • We will not be in high risk settings • Minor shaking: no hazard • Major or prolonged shaking: Get outside • Avoid buildings and power lines • Trees are well engineered seismically • If inside, get under something sturdy or brace in a doorway.

4. Tsunamis • Warning Signs • Strong earthquake on coast • Abrupt changes in sea level – up or down • Get to high ground or inland immediately • Do not pass Go, do not collect $200

5. Volcanism • We will not go anywhere near active volcanoes or known hazardous areas. • If activity occurs, we will evacuate immediately • I am a volcano expert. If you see me running, try to catch up.

6. Slope Hazards • Landslides due to earthquakes • Mudflows due to heavy rains • Get out of the way • Get off slope if you sense movement • Get away from streams if water level starts to rise

7. Rips • When waves break parallel to a beach, rips occur

8. Rips, Lake Superior

9. Oblique Rips

10. A Subduction Zone

15. How Arcs Grow

19. Exotic Terranes

28. Fit of Continents Across the Atlantic

29. The Caribbean

31. Opening of the North Atlantic

33. Yucatan Rifts Away

38. Volcanic Plateau Begins to Form

40. Plateau Encounters Subduction Zone

43. Yucatan Basin Opens

46. East Pacific Rise Approaches

48. Now