1. EARTHQUAKES

2. Earthquake Facts
An earthquake is the shaking and trembling that results from sudden movement of the earth’s crust.
They occur along plate boundaries where tension builds between rock layers.
There are over 150,000 earthquakes every year, however only about 75 of these are significantly strong enough to be felt by people.

3. Map of earthquakes in the past three days (Jan, 2002)

4. Map of earthquakes in the past week.

5. Map of earthquakes in the past month, Dec15-Jan15, 2002.

7. Focus / Epicenter
Focus - The point below the earth’s surface where the rock breaks.
Epicenter - point on the surface directly above the focus.
In general, a shallow focus earthquake causes more damage than a deep focus earthquake.

9. The Seismograph

10. P S and Surface Waves
P Waves arrive first and go through solid and liquid. These are compression waves.
S Waves arrive second and only go though solid. They travel at right angles to the shock wave.
Surface waves arrive last and do most of the damage. They are similar to waves on the surface of a lake or ocean.

13. Earth’s Interior
P & S waves act like a probe revealing the earth’s interior.
Remember that P-waves travel through both liquid and solid while S-waves travel only through solids.

14. If the earth had a solid core this would represent the S/P waves.

15. The outer core is liquid
Because earth has a liquid outer core there is an S-wave shadow zone on the opposite side of the world.

17. Distribution of Earthquakes

18. Tsunami
An underwater disturbance such as an earthquake or volcano can cause a Tsunami.

21. 1946, a man stands before a wall of water about to engulf him in Hilo, Hawaii

22. Tsunami damage in Hawaii from the 1960 Chilean quake.

23. The Richter Scale

25. A photo gallery of famous quakes

26. Orange Trees Displaced along the San Andreas Fault

28. North Ridge California, 1994

29. North Ridge California, 1994

30. Mexico City 1985 Liquefaction

31. Mexico City, 1985

32. Tangshan China 1976

33. San Francisco 1906

34. San Francisco

35. Chili 1960 Mag 9.5!

36. Alaska 1964

37. Peru 1970

38. San Francisco 1989

39. Kobe Japan, 1995

40. San Fernando California 1971

41. Some famous earthquakes
New Madrid Missouri 1811&1812
San Francisco 1906 (fire damage)
Alaska 1964 (Good Friday quake)
1970 Peru (deadliest in South America)
Tangshan China 1976 (deadliest this cent.)
Mexico City 1985 (liquefaction damage)
Chili 1960 (Most powerful Earthquake)

42. New Madrid Missouri 1811&12
In 1811 & 1812 there were three major earthquakes that rocked the central U.S.
The New Madrid fault line is an old plate boundary.
The Mississippi River changed its course after these powerful earthquakes.

43. San Francisco 1906
This 8.3 magnitude earthquake ruptured many gas lines and destroyed the city.
1500 people died many from the resulting fires.
The San Andreas fault line shifted 21 feet!

44. Peru 1970
66,000 people died making it the deadliest earthquake in South America.
The 7.8 magnitude quake had a high death toll because many of the adobe houses collapsed and there were massive landslides in the Andes.

45. Alaska 1964
This 8.7 magnitude earthquake was one of the most powerful in modern times.
The quake lasted four minutes however the death toll was only 130.

46. Tangshan China, 1976
At 3:40 in the morning on July 28th 1976 a 7.8 magnitude quake obliterated the city of Tangshan China.
Approximately 500,000 people died making it the deadliest quake in the twentieth century.

47. Strange Phenomena in Tangshan
Well water rose & fell three times the day before the quake occurred.
Chickens refused to eat and mice were seen running around looking for hiding places.
The night before, people saw strange lights and loud sounds in the sky. (A similar phenomena occurred in Mexico city, 1985.)

48. Mexico City 1985
Over 9,000 people died from an 8.1 magnitude earthquake.
Liquefaction - caused much of the damage.
Liquefaction is when once stable soil turns into a fluid and cannot support buildings.

49. End of part I: Earthquakes Continue for part II: Volcanoes

50. Volcanoes

51. Presentation Outline 1. Cinder Cone Volcanoes 2. Shield Volcanoes
3. Stratovolcano or composite cone
4. Flood Basalts
5. Volcanic features
6. Volcano vocabulary

52. Basic Facts on Volcanoes
There are over 600 active volcanoes. 2/3 of these are found along the ring of fire tectonic plate boundary.
There are three basic types of volcanoes:
1. Shield Volcanoes.
2. Stratovolcano or composite cone.
3. Cinder Cone Volcanoes.

53. Location of earthquakes & volcanoes

54. The three types of Volcanoes

55. Cinder Cone Volcanoes
These are generally small volcanoes that build up from ejected lava and rock fragments.

56. Sunset Carter in Arizona is a typical cinder cone volcano

57. Sunset crater

58. Paracutin: Cinder Cone
In 1943 a cinder cone volcano grew in a farmer’s corn field west of Mexico City.
In one day the cone grew grew over 130 feet.

59. Paracutin 1943, Mexico

60. Paracutin

61. Paracutin

62. Church near Paracutin

63. Capulin Cinder Cone Volcano, New Mexico

64. Capulin New Mexico

65. Shield Volcanoes
Shield Volcanoes have a very broad base and gentle slope.
The Hawaiian Islands are classic shield volcanoes.
Shield Volcanoes generally have gentle liquid lava eruptions.
Mauna Loa is the largest volcano on Earth!

66. Shield volcanoes

67. The Hawaiian Shield Volcanoes

68. Mauna Loa, from its base to summit is 30,000 feet!

69. Two types of Lava Pahoehoe is smooth rope like lava
AA lava is rough and angular
Both types of lava are associated with shield volcanoes.

70. Pahoehoe & AA Lava

71. Stratovolcano or composite cone
The stratovolcano or composite cone represents your “typical” volcano.
These Volcanoes are cones made of alternating layers of lava and pyroclastic rock layers.

72. The Stratovolcano

73. Stratovolcano

74. Indonesia, Where 67% of all volcanic related deaths occur.

75. Tambora Indonesia

76. The Tambora Eruption 1815
This was the most powerful eruption in recorded history and had the highest death toll.
Over 92,000 died from this eruption mostly from starvation was known around the world as “the year without a summer.”
Ash from Tambora block sunlight causing massive starvation around the world.

77. Krakatoa Indonesia before & after 1883

78. Krakatoa 1883
When Krakatoa erupted it blew away 2/3 of the uninhabited island.
The Tsunami that resulted killed over 36,000 people on the nearby island of Java.
The explosion was so powerful it was heard 3,000 miles away in Australia!

79. Krakatoa today

80. Krakatoa

81. Mt. Vesuvius & Pompii Italy
For over 16 years earthquakes shook the Roman city of Pompii Italy.
In 79 AD Mt. Vesuvius finally exploded causing hot ash and sulfur gases to bury the city of Pompii.
Over 20,000 Romans were fossilized from the explosion of Mt. Vesuvius.

82. Mt Vesuvius & Italy

83. A fossilized dog from Pompii

84. A Roman Soldier

85. A recent 1944 eruption of Mt. Vesuvius

86. Mt. Pelee & the city of Martinque
In 1902 Mt. Pelee erupted destroying the Caribbean city Martinque.
29,000 people died. The only survivor was a prisoner in an underground jail.
Nuee ardent is a hot ash flow and caused most of the destruction.

87. Mt. Pelee today

88. Mt. Pelee in 1902

89. Mt. Pelee

90. The destruction of Martinque

91. The Cascade Mountain Range
The Cascade Mountain range is located in the North West United States and contains some of the most famous volcanoes.
These include: Mt. St. Helens, Crater lake, Mt. Ranier, Mt. Baker, Mt. Hood, Mt. Shasta, Mt. Hood, to name a few.

93. Crater Lake Oregon
About 6,000 years ago Mt. Mazama in Oregon blew its top creating a large caldera.
This caldera filled in with water creating the 6 mile wide Crater Lake National Park.

94. How Crater Lake formed

95. Crater Lake Oregon

96. Crater Lake & Wizard Island

97. Crater Lake & Wizard Island

98. Mt. St. Helens 1980
On May 18, the dormant volcano Mt. St. Helens in Washington state erupted.
The top 1,300 feet of the mountain disappeared in a few minutes.

100. Mt. St. Helens, May 1980

101. The ash fall-out from Mt. St. Helens

102. Diagram of the eruption

103. Mt. St. Helens after 1980

105. Mt. St. Helens today

106. Volcanic flood basalts
Liquid lava comes up from cracks or fissures in the earth’s crust. This lava can cover many square miles of earth.
The dark mare on the moon are flood basalts.

107. Deccan India Deccan India is the worlds largest flood basalt.
The region in west central India is called the Deccan traps.
The Deccan traps are composed of black basalt 6,500 feet thick.

108. Deccan India

109. Deccan traps, India

110. The Columbia River flood Basalts
A large region of the U.S. extending from Yellowstone Wyoming to the Columbia River in Washington is composed of flood basalt.

111. Flood Basalts in North West U.S.

112. Arial view of flood basalts

113. Columbia River Flood Basalt

114. Columbia River flood basalt

115. El Malpais National Monument
A flood basalt igneous rock region extends from New Mexico to Arizona and includes the El Malpais (bad land) national monument.

116. El Malpais New Mexico

117. Arial view of flood basalt in New Mexico

118. El Malpais New Mexico

119. Lava tube in El Malpais

120. Volcanic Necks
When erosion removes the softer rock around a volcano the more resistant volcanic neck is exposed.
Ship rock New Mexico and Devil’s Tower are two examples of an exposed volcanic neck.

121. The volcanic neck

122. Erosion exposes the neck

123. Devil’s Tower Wyoming

124. Devil’s Tower

125. Formation of a Volcanic Neck

126. Ship Rock New Mexico

127. Ship Rock New Mexico

128. Volcanic Vocabulary Nuee ardente is a fiery cloud of hot gas.
Lahar mudslides that result from a volcanic eruption.

129. Nuee Ardente

130. Lahar

131. Three levels of volcanic activity
1. Extinct - has not erupted in recorded history.
2. Dormant - has erupted in recorded history but is currently “sleeping.”
3. Active - means it is currently erupting.

132. The End