Q1W5 - SCIENCE 10 - TYPES OF PLATE BOUNDARIS.ppt
- 2. Theory of Plate Tectonics Theory of Plate Tectonics Plate Tectonics Plate Tectonics Plate Boundaries Plate Boundaries Causes of Plate Tectonics Causes of Plate Tectonics
- 4. What is Plate Tectonics What is Plate Tectonics • The Earth’s crust and upper mantle are broken into sections called plates • Plates move around on top of the mantle like rafts
- 6. What is the What is the Lithosphere Lithosphere? ? • The crust and part of the upper mantle = lithosphere –100 km thick –Less dense than the material below it so it “floats”
- 7. What is the What is the Asthenosphere Asthenosphere? ? • The plastic layer below the lithosphere = asthenosphere • The plates of the lithosphere float on the asthenosphere
- 9. 2 Types of Plates 2 Types of Plates • Ocean plates - plates below the oceans • Continental plates - plates below the continents
- 10. Questions... Questions... • What is the theory of plate tectonics? • What is the lithosphere? • What is the asthenosphere? • What is the connection between the two? • What are the two types of plates?
- 12. Convergent Boundaries Convergent Boundaries • Boundaries between two plates that are colliding • There are 3 types…
- 13. Type 1 Type 1 • Ocean plate colliding with a less dense continental plate • Subduction Zone: where the less dense plate slides under the more dense plate • VOLCANOES occur at subduction zones
- 14. PLATE A PLATE B
- 16. Type 2 Type 2 • Ocean plate colliding with another ocean plate • The less dense plate slides over the more dense plate creating a subduction zone called a TRENCH
- 18. Aleutian Islands, Alaska Aleutian Islands, Alaska
- 19. Type 3 Type 3 • A continental plate colliding with another continental plate • Have Collision Zones: –a place where folded and thrust faulted mountains form.
- 22. Divergent Boundaries Divergent Boundaries • Boundary between two plates that are moving apart or rifting • RIFTING causes SEAFLOOR SPREADING
- 23. Features of Divergent Features of Divergent Boundaries Boundaries • Mid-ocean ridges • rift valleys • fissure volcanoes
- 27. Transform Fault Boundaries Transform Fault Boundaries • Boundary between two plates that are sliding past each other • EARTHQUAKES along faults
- 29. San Andreas Fault, CA San Andreas Fault, CA
- 30. Questions... Questions... • What are the three types of boundaries? • What direction do plates go for each? • Which boundary has a subduction zone…what occurs at a subduction zone?
- 31. Causes of Plate Causes of Plate Tectonics Tectonics
- 32. Convection Currents Convection Currents • Hot magma in the Earth moves toward the surface, cools, then sinks again. • Creates convection currents beneath the plates that cause the plates to move.
- 34. PROCESSES AND PROCESSES AND LANDFORMS LANDFORMS ALONG PLATE ALONG PLATE BOUNDARIES BOUNDARIES
- 35. EARTHQUAKE EARTHQUAKE • A sudden shaking of the ground cause by a tremendous release of energy due to pressure in Earth’s crust. • As the pressure builds up, stress increases in the crust
- 36. PARTS OF AN EARTHQUAKE PARTS OF AN EARTHQUAKE FAULT – the slipping of a block of Earth’s crust with another block.
- 37. PARTS OF AN EARTHQUAKE PARTS OF AN EARTHQUAKE FOCUS – the origin at which the earthquake occurs.
- 38. PARTS OF AN EARTHQUAKE PARTS OF AN EARTHQUAKE EPICENTER – the point directly above the focus on the surface.
- 39. SEISMIC WAVE SEISMIC WAVE • waves generated by an earthquake or explosion. • It travel along and within the lithosphere. • These waves are in the form of Body wave and Surface wave.
- 40. BODY WAVE BODY WAVE • Travel through earth’s interior. 2 Forms of Body Wave 1. Primary wave (P-wave) – travel through the interior of Earth and through solid and fluid materials. • Travels faster than S-wave. • The detected wave that the Earthquake produces.
- 41. BODY WAVE BODY WAVE 2 Forms of Body Wave 2. Secondary wave (S-wave) - a seismic body wave that shakes the ground back and forth perpendicular to the direction the wave is coming. •travel through solid materials only within the interior of Earth. •Travels slower than P-wave. •The detected wave that the Earthquake produces.
- 43. SURFACE WAVE SURFACE WAVE • Travel on earth’s surface. • Love wave or Rayleigh wave – moves in the ground in horizontal position. • Discovered by Augustus Edward Love
- 45. SIZE OF EARTHQUAKE: MAGNITUDE AND INTENSITY SIZE OF EARTHQUAKE: MAGNITUDE AND INTENSITY Magnitude •it is the quantitative measure of the amount of energy released by an earthquake. •It is measured using a seismograph. •The Richter scale is the most common scale for the magnitude of an earthquake. Intensity •Refers to the strength of ground shaking during an earthquake. •Also refer to the amount of damage caused by an earthquake. •Intensity varies in different areas or places depending on the distance from the epicenter of an earthquake. •Rossi-Forel Intensity Scale – the first scale used in identifying the intensity of an earthquake •Modified Mercalli Intensity Scale – now widely-used scale.
- 46. EFFECTS OF EARTHQUAKES EFFECTS OF EARTHQUAKES • The most destructive recorded earthquake that hit the country happened at the Moro Gulf in 1976, with a magnitude of 8.0 and is tectonic in origin. • The earthquake occurred near the Cotabato Trench, which is known as a region of subduction in the Southern Philippines. • This earthquake has even reached the Visayas region due to its intense shaking. • It also caused tsunami that was 4.5 m high.
- 47. Questions... Questions... • What causes plates to move? • How is a convection current formed?
Editor's Notes
- #14: Activity 2:A Converging Continental Plate and Oceanic Plate