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PLATE TECTONICS

PLATE TECTONICS

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PLATE TECTONICS

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  1. PLATE TECTONICS Chapters 7, 8, & 9 Test 2 material End

  2. LEGEND • AZTEC INDIANS OF MEXICO SACRIFICED HUMANS TO KEEP AWAY EARTHQUAKES AND TO KEEP SUN ALIVE BY CUTTING OUT THE HEARTS OF THEIR VICTIMS AND THROWING THEM INTO VOLCANO

  3. LEGEND • IN WESTERN AFRICA THOUGHT THE JUNGLE WAS THE HAIR OF A GIANT. ALL LIVING THINGS THAT CREPT OR CRAWLED IN THE JUNGLE WERE LIKE LICE IN THE GIANT’S HAIR. EARTHQUAKES WERE EXPLAINED AS THE GIANT SHAKING HIS HEAD TO GET RID OF THE LICE

  4. LEGEND • IN POLYNESIA TWO GODDESSES WERE FIGHTING THEIR WAY ACROSS THE PACIFIC. WHEREVER AN EARTHQUAKE OR VOLCANO OCCURRED, THIS WAS A BATTLE SITE. WHEN A GODDESS WAS SPURNED BY A LOVER SHE THREW A TANTRUM AND LAVA FLOWED

  5. LEGEND • VULCAN WAS THE ROMAN GOD WHO HAD A FORGE AT THE CENTER OF THE EARTH TO MAKE WEAPONS FOR THE GODS. WHENEVER HIS FORGE WAS WORKING LAVA SPEWED FORTH AT THE SURFACE.

  6. LEGEND • IN ICELAND VIKING LEGEND TALKS OF ODIN & FRIGGA AND THEIR BELOVED SON BALDER. THE GOD OF MISCHIEF, LOKI, CONSPIRED TO HAVE BALDER KILLED.

  7. FAMOUS VOLCANOES IN HISTORY • MOUNT VESUVIUS • MOUNT PELEE - WITH GLOWING CLOUD (NUEE ARDENTE) • PARICUTIN • KRAKATOA

  8. VESUVIUS

  9. MT PELEE

  10. PARICUTIN

  11. Volcanoes – Birth of Paricutin

  12. FAMOUS EARTHQUAKES • GREAT ALASKA QUAKE OF 1964 • GREAT CHINA QUAKE • NEW MADRID QUAKES OF 1811-1812 • MISSISSIPPI RIVER STOOD UP ON END • CHURCH BELLS RANG IN BOSTON • http://www.youtube.com/watch?v=4Y-62Ti5_6s • Pakistan quake of 2006

  13. DR. IBEN BROWNING • 1990 PREDICTED A 50% CHANCE OF EARTHQUAKE OF 6.5 - 7.5 IN NEW MADRID BETWEEN DEC. 1-5, 1990 • CLAIMED A GREAT TIDAL STRAIN WOULD ALSO STRAIN THE SUBSURFACE • RECEIVED NOTORIETY FOR PREDICTING SF QUAKE OF 1989

  14. ARGUMENTS AGAINST DR. BROWNING’S THEORY • NO FIRM SCIENTIFIC SUPPORT FOR HIS THEORY • WAS A BIOLOGIST SPECIALIZING IN CLIMATOLOGY AND WAS NOT A GEOLOGIST OR SEISMOLOGIST • ERRONOUS CLAIM TO FAME FOR PREDICTING SAN FRANCISCO EARTHQUAKE OF 1989

  15. TRANSCRIPTS REVEALED BROWNING PREDICTED AN EARTHQUAKE OF 6.0+ WOULD OCCUR SOMETIME ON OR AROUND OCT 16TH (ACTUAL QUAKE WAS 17TH) SOMEWHERE IN WORLD. • THESE QUAKES HAPPEN EVERY 3 DAYS SO NOT MUCH OF A FORECAST

  16. THE ONLY GEOLOGIST IN THE NATION SUPPORTING HIM HAD SHAKEY REPUTATION. HAD FLOWN OVER THE STATE OF NORTH CAROLINA USING A PSYCHIC TRYING TO LOCATE AREAS WHERE AN EARTHQUAKE WOULD STRIKE

  17. ALFRED WEGENER • THEORY OF CONTINENTAL DRIFT & PLATE TECTONICS • PANGAEA • LAURASIA • GONDWANA • GLOSSOPTERIS

  18. WHAT WAS EFFECT OF CONTINENTAL MOVEMENT? • NEW CLIMATES ALONG COASTS • NEW MOUNTAIN RANGES • NEW DESERTS • DRIFTING OF THE POLES • PLANT AND ANIMAL LIFE SIMILARITIES IN AREAS ONCE UNITED

  19. SEA FLOOR SPREADING • WEGENER’S HYPOTHESIS WAS NOT READILY ACCEPTED BECAUSE IT FAILED TO PROVIDE MECHANISM FOR MOVEMENT • ARTHUR HOLMES, GEOLOGIST THOUGHT THE SEA FLOORS WERE DRAGGING ALONG THE CONTINENTS WHICH RESTED ON TOP OF THEM

  20. Seafloor spreading

  21. THOUGHT CONVECTION PROCESS BEGAN BELOW EARTH’S SURFACE WHICH PUSHED MATERIAL UPWARD TO FORM RIDGE SYSTEMS ON OCEAN FLOOR. MATERIAL WIDENS THE OCEANS BY 1 OR 2 INCHES PER YEAR

  22. WHAT DID HOLMES FIND ON OCEANIC RIDGES? • EQUAL DISTANCE • EQUAL AGE • EQUAL THICKNESS • EQUAL MAGNETIC DIRECTION • WHAT DOES THIS SUGGEST?

  23. PLATE BOUNDARIES • DIVERGENT • CONVERGENT • TRANSFORM

  24. DIVERGENT PLATE BOUNDARIES • FOUND NEAR SPREADING CENTERS & AT THE MID-OCEANIC RIDGE SYSTEMS • RIFT VALLEYS • GREAT RIFT VALLEY OF AFRICA

  25. divergent

  26. Rift valley

  27. East africa rift

  28. CONVERGENT PLATE BOUNDARIES • OCEAN & CONTINENT • OCEAN & OCEAN • CONTINENT & CONTINENT

  29. convergent

  30. Continent to continent

  31. Ocean to ocean

  32. TRANSFORM PLATE BOUNDARIES • SAN ANDREAS FAULT • MOVING TO NORTH/NORTHWEST AT A RATE OF 35 MILLIMETERS PER YEAR

  33. transform

  34. EARTHQUAKE • VIBRATION OF THE EARTH PRODUCED BY THE RAPID RELEASE OF ENERGY ALONG FAULTS • THIS ENERGY RADIATES OUTWARD FROM THE SOURCE OF THE QUAKE KNOWN AS THE FOCUS

  35. focus

  36. Elastic rebound

  37. EPICENTER • THE AREA ON THE EARTH’S SURFACE IMMEDIATELY ABOVE THE FOCUS • IT IS NOT THE SOURCE OF THE QUAKE

  38. FAULTS • PRODUCED BY THE NEVER ENDING MOVEMENT OF THE EARTH’S CRUST • FIND FAULTS AND EARTHQUAKES NEAR PLATE BOUNDARIES

  39. OTHER QUAKES • FORESHOCKS - QUAKES THAT PRECEDE THE MAIN EARTHQUAKE • AFTERSHOCKS - QUAKES THAT FOLLOW THE MAIN EARTHQUAKE

  40. EARTHQUAKE RECORDINGS • SEISMOLOGY • SEISMOGRAPH • SEISMOGRAM • RICHTER SCALE - LOGARITHMIC SCALE USED TO MEASURE THE ENERGY AND THE WAVE AMPLITUDE OF THE EARTHQUAKE

  41. seismograph

  42. seismogram

  43. . • ONE MILLION EARTHQUAKES OCCUR EVERY YEAR • 6.0 OCCURS EVERY THREE DAYS • ABOVE 8.0 ONCE EVERY 5/10 YEARS • BELOW 2.5 ARE NOT FELT BUT CAN BE MEASURED

  44. RICHTER SCALE INCREMENTS • AN INCREASE OF 1.0 = A 10 TIMES INCREASE IN WAVE AMPLITUDE AND A 31.5 TIMES INCREASE IN ENERGY • AN INCREASE OF 2.0 = A 100 TIMES INCREASE IN AMPLITUDE AND A 992.25 INCREASE IN ENERGY (31.5 X 31.5)

  45. EARTHQUAKE WAVES • SURFACE WAVES - TRAVEL ALONG EARTH’S OUTER LAYER • BODY WAVES - TRAVEL THROUGH EARTH’S INTERIOR • PRIMARY WAVES [P WAVES] - COMPRESS & EXPAND ROCKS IN THE DIRECTION WAVE TRAVELS • SECONDARY WAVES [S WAVES] - SHAKE THE PARTICLES AT RIGHT ANGLES TO DIRECTION OF TRAVEL