2. Earth Shakes, Rattles, and Rolls Plate Tectonics Volcanoes Earthquakes

3. What is the relationship between the earth’s plates, volcanoes, and earthquakes?

4. http://www.extremescience.com/PlateTectonicsmap.htm Plates

5. Earthquakes

6. http://hsv.com/scitech/earthsci/quake.htm Volcanoes

7. Let’s look at those maps again.

8. Plates Earthquakes Volcanoes

9. Earthquakes and Volcanoes are found where plates meet.

10. Formation of a Volcano

11. Lava When the magma reaches the surface, it is called lava. In some places, lava can build up to forma cone-shaped mountain. The lava erupts from the vent. Volcanoes often have more than one vent. There are 4 types of lava

12. Dark-Colored Lava dark-colored and contains a lot of water. rich in iron and magnesium cools to form igneous rocks such as basalt. thin and runny and most tends to flow. The islands of Hawaii and Iceland were formed by many lava flows.

13. Light-Colored Lava contains little water and is rich in silicon and aluminum. causes explosive eruptions. Silicon tends to harden in the vents and form rocks. Steam and new lava build up under the rocks. When the pressure becomes great, a violent explosion occurs. When it cools it form the igneous rock, rhyolite, which resembles granite.

14. Combination Lava has a chemical composition similar to that of both the dark-colored type and the light- colored type. Different varieties of igneous rocks in the Earth’s crust, such as andesite, are form from this type of lava.

15. Gaseous Lava contains large amounts of gases such as steam and carbon dioxide. When this lava hardens, it forms rocks with many holes in them, due to gas bubbles. Pumice and scoria are igneous rocks formed from this type of lava.

16. Volcanic Eruptions many rock fragments are blown into the air. The smallest particles are called volcanic dust. (less than 0.25 mm) Volcanic Ash ( 0.25 -5mm) falls to the Earth and forms small rocks. Volcanic bombs (a few cm to several meters) are molten and harden as they travel through the air.

17. Types of Volcanos Composite Cinder Cone Shield

18. http://images.google.com/imgres?imgurl=http://www.cotf.edu/ete/images/modules/volcanoes/typesb.GIF&imgrefurl=http://www.cotf.edu/ete/modules/volcano es/vtypesvolcan1.html&h=236&w=265&sz=14&tbnid=qZF0vXnHnOkJ:&tbnh=96&tbnw=107&start=19&prev=/images%3Fq%3Dcomposite%2Bvolcano%2 6hl%3Den%26lr%3D%26sa%3DN have small craters in their summits Vesuvius, Krakatoa, Fujiyama, and Mount St. Helens tens of miles across and ten thousand or more feet in height.

19. http://images.google.com/imgres?imgurl=http://www.cotf.edu/ete/images/modules/volcanoes/t ypesb.GIF&imgrefurl=http://www.cotf.edu/ete/modules/volcanoes/vtypesvolcan1.html&h=23 6&w=265&sz=14&tbnid=qZF0vXnHnOkJ:&tbnh=96&tbnw=107&start=19&prev=/images% 3Fq%3Dcomposite%2Bvolcano%26hl%3Den%26lr%3D%26sa%3DN consist almost entirely of loose, grainy cinders and almost no lava steep sides and usually have a small crater on top small volcanoes form from explosive eruptions

20. http://images.google.com/imgres?imgurl=http://www.cotf.edu/ete/images/modules/volcanoes/typesb.GIF&imgrefurl=http://www.cotf.edu/ete/modules/volcanoes/vtypesv olcan1.html&h=236&w=265&sz=14&tbnid=qZF0vXnHnOkJ:&tbnh=96&tbnw=107&start=19&prev=/images%3Fq%3Dcomposite%2Bvolcano%26hl%3Den%26lr%3 D%26sa%3DN hundreds of miles across and many tens of thousands of feet high. Mauna Loa consist almost entirely of frozen lavas large craters at their summits.

21. largest single mountain in the world 30,000 +feet above the ocean floor 100 miles across at its base.

22. Crater funnel-shaped pit or depression at the top of a volcanic cone. If the crater becomes very large as a result of the collapse of its walls, it is called a caldera. A caldera may also form when the top of a volcano explodes or collapses.

23. Volcanic Activity Volcanoes are rather unpredictable. Some erupt regularly, others have not erupted in modern history. Scientists classify them as active, dormant or extinct.

24. Active Volcanoes Erupts continually or periodically such as Mount Katmai in Alaska and Mount St. Helens in the Cascade Range.

25. Dormant Volcano has been known to erupt within modern times but is now inactive is classified as a dormant volcano. Mount Rainier in Washington state

26. Extinct Volcano not known to have erupted within modern history is an extinct volcano. They have been worn away almost to the level of their magma chamber. Scientists can be wrong. Mount St. Helens was considered to be dormant but erupted after long periods of inactivity.

28. Convection currents in the Earth's mantle are what drive plate motions. Convection currents are driven by the simple fact that hot things (such as gases and liquids) rise while cool things fall.

29. Convection currents in the magma move the earth’s crust.

30. Earthquakes the shaking and trembling that results from the sudden movement of part of the Earth ’ s crust. The most common cause of earthquakes is faulting. During faulting, energy is released. Rocks continue to move until the energy is used up.

31. Focus Most faults occur between the surface and a depth of 70 kilometers. The point beneath the surface where the rocks break and move is called the focus. The focus is the underground origin of an earthquake.

32. Epicenter Directly above the focus, on the Earth ’ s surface is the epicenter. Earthquake waves reach the epicenter first. During an earthquake, the most violent shaking is found at the epicenter.

33. http://uc.wisc.edu/news/features/quake/pwaves.html

34. Seismic Waves There are three main types of seismic waves. Primary Secondary Surface

35. Primary Waves Seismic waves that travel fastest are P waves. They travel through solids, liquids and gases. They move at different speeds depending on the density of the material through which they are moving. As they move deeper in the Earth they move faster. P waves are push-pull waves.

36. Secondary Waves Seismic waves that do not travel through the Earth as fast as P waves do are called secondary or S waves. S waves travel through solids but not liquids or gases. S waves cause particles to move from side to side. They move at right angles to the direction of the wave.

37. Surface Waves The slowest moving seismic waves are called surface waves or L waves. L waves originate on the Earth ’ s surface at the epicenter. They move along the surface the way waves travel in the ocean. The Earth ’ s surface moves up and down with each L wave. L waves cause most of the damage.

38. Earthquakes How do we measure the intensity of an earthquake?

39. Seismograph measures or the strength of an earthquake

40. The Seismograph Invented in 1893 by John Milne, a seismograph detects and measures seismic waves. A weight attached to a spring remains nearly still even when the Earth moves. A pen attached to the weight records any movement on a roll of paper on a constantly rotating drum. The drum moves with the Earth and affects the line.

41. Seismograph records energy waves of the earth

42. The Richter Scale The amount of damage created by an earthquake depends on several factors. The earthquake ’ s strength The kind of rock and soil that underlie an area The population of the area The kind of buildings in the area The time at which the earthquake occurs

43. Predicting Earthquakes Scientists have identified warning signals the help predict earthquakes with greater accuracy. Often changes occur in the speed of P and S waves before an earthquake occurs. Sometimes slight changes in the tilt of the Earth ’ s surface can be detected. Some scientists believe animals behavior is affected.

44. V. People feel movement. Doors open Pictures fall off wall. VII. Some buildings lose bricks. Difficulty driving. IX. Considerable damage to homes. Cracks in earth. XII. Almost everything is destroyed. The ground moves in waves or ripples. Mercalli Scale I.People do not feel anything.

45. Richter Scale Earthquake Magnitudes Effects Less than 3.5 Generally not felt 3.5-5.4 Rarely causes damage. Under 6.0 Slight damage to well-designed buildings. 6.1-6.9 Destructive to about 100 kilometers across 7.0-7.9 Major earthquake. Serious damage over larger areas. 8 or greater Great earthquake.

46. Each number is 10X stronger than the previous number. How much stronger is the 3 than the 1? 100 Times How much stronger is the 8 than the 1? 10,000,000 Write the number in scientific notation. 10 6

47. Why is the Richter Scale more accurate than the Mercalli Scale? The Richter Scale is objective and based on mathematical measurements. The Mercalli scale is subjective and based on people’s perception and experience. On Mercalli scale if the area is unihabited there is no way to measure the magnitude of the earthquake.

48. Richter MagnitudeNumber of Earthquakes per year 1.0 to 3.9900,000 + 4.0-4.96200 5.0-5.9800 6.0-6.9226 7.0-7.918 8.0-8.9Less than 2

49. San Francisco Earthquake 1906

50. Alaska Earthquake 1964

51. Earthquakes in the ocean cause

52. Destruction 30’ Wall of Water

53. Tsunamis Earthquakes which occur on the ocean floor produce giant sea waves called tsunamis. Tsunamis can travel at speeds of 700 to 800 km per hour. As they approach the coast, they can reach heights of greater than 20 meters.

54. Types of Mountains Folded Fault-block Volcanic Unwarped

55. http://www.cssd11.k12.co.us/dohnts/images/earth/fldmtn.jpg FOLDED MOUNTAINS

56. Appalachian Mountains in the eastern United States, and the Swiss Alps in Switzerland form when two plates collide head on, and their edges crumble consist mainly of sedimentary rocks, like limestone and shale

57. FAULT-BLOCK MOUNTAINS

58. FAULT-BLOCK MOUNTAINS Consist of huge blocks of the earth's crust that have been tilted or pushed up along a fracture line called a fault Sierra in California, Arizona is an example. Created when a plate hits a fault and tips upside down, creating erosion and debris, which is at the base of the mountain.

59. VOLCANIC MOUNTAIN NAMIBIA IN AFRICA

60. Volcanic mountains Formed when molten rock, or magma deep within the earth, erupts, and piles upon the surface Made of basalt and rhyolite. Takes place where two of the earth's tectonic plates collide.

61. UNWARPED MOUNTAINS Black Hills in South Dakota form when tectonic forces lift the earth's crust into a broad bulge or dome raising it above its surroundings Erosion causes peaks and valleys to form.

62. http://www.enchantedlearning.com/subjects/volcano/labelvol cano.shtml http://images.google.com/imgres?imgurl=http://www.cotf.edu/ete/images/modules/volcanoes/typesb.GIF&imgrefur l=http://www.cotf.edu/ete/modules/volcanoes/vtypesvolcan1.html&h=236&w=265&sz=14&tbnid=qZF0vXnHnOk J:&tbnh=96&tbnw=107&start=19&prev=/images%3Fq%3Dcomposite%2Bvolcano%26hl%3Den%26lr%3D%26sa %3DN Image Resources For additional diagrams of volcanoes click below: