Earthquakes Theres a whole lotta shakin goin on

Earthquakes: There’s a whole lotta shakin’ goin’ on Dr. William D. (Bill) Underwood Chesapeake Energy Chair of Geosciences Ok. School of Science & Math. 1

Definition An earthquake is a sudden movement of the earth resulting from abrupt release of accumulated strain. Earthquakes are classified according to their depth. Shallow < 60 km Intermediate < 300 km Deep > 300 km (sometimes > 450 km) 2

Wave Types • Surface waves – Travel at interface – Love waves – Rayleigh waves – Eg ocean waves • Body waves – P-waves – S-waves 3

Seismograms 3 seismometers used to measure 3 components (x, y, z) 4

Seismograms 5

Seismograms 6

Fault Types • Strike-slip Fault – Lateral motion • Normal Fault – Extension • Reverse Fault – Compression • Thrust Fault – Low-angle reverse fault 7

Strike-slip Fault Left-lateral Right-lateral 8

San Andreas Fault (r-l) 9 Miller

Normal Fault 10

Normal Fault Miller 11

Reverse Fault 12

Thrust Fault 13 Maher

Earth Structure Shows P-waves No S-waves through core 14

The Mid-Continent 15

Plate Tectonics 16

Plate Tectonics 17

World’s Largest Earthquakes Date Time Lat. Long. Mag. Location 1960/05/22 19: 11 38. 29 S 73. 05 W 9. 5 Chile 1964/03/28 3: 36 61. 02 N 147. 65 W 9. 2 Prince William Sound 2004/12/26 00: 59 3. 30 N 95. 78 E 9. 1 Northern Sumatra 2011/03/11 05: 46 38. 32 N 142. 37 E 9. 0 Offshore Honshu, Japan 1952/11/04 16: 58 52. 76 N 160. 06 E 9. 0 Kamchatka 2010/02/27 06: 34 35. 85 S 72. 72 W 8. 8 Offshore Chile 1906/01/31 15: 36 1. 00 N 81. 50 W 8. 8 Off the Coast of Ecuador 1965/02/04 05: 01 51. 21 N 178. 50 E 8. 7 Rat Islands, Alaska 2005/03/28 16: 09 2. 08 N 97. 01 E 8. 6 N. Sumatra, Indonesia 1950/08/15 14: 09 28. 50 N 96. 50 E 8. 6 Assam-Tibet 1957/03/09 14: 23 51. 56 N 175. 39 W 8. 6 Andreanof Islands, Alaska 18

Why do we care? Earthquake Risk 19

Oklahoma Let’s look closer to home 20 USGS

Oklahoma 1977 -2001 21

Magnitude 3. 5 or Greater 22

Oklahoma Jones January 15, 2010 23

Oklahoma Where the people are 24

Oklahoma Prague Nov. 5, 2011 M 5. 6 25

Oklahoma Who felt it? 26

Oklahoma November 5, 2011 • • M 5. 6 main shock at 10: 52 PM M 4. 7 foreshock at 2: 12 AM Hundreds (thousands? ) of aftershocks Felt over a wide area No loss of life; few (no? ) injuries Little damage to property Tremendous excitement (and anxiety) 27

Oklahoma November 5, 2011 • Along a known fault (Wilzetta Fault) of a known tectonic feature (Seminole Uplift) • In basement rock, well below oil activity • Injection is at very low pressures • Major faults have been know in recent geologic past (e. g. Meers) • Mid-continent quakes studied < 200 yrs 28

Date UTC Lat. Long. World Mag. Rank Region 1964/03/28 03: 36 61. 04 N 147. 73 W 9. 2 2 Prince William Sound 1965/02/04 05: 01 51. 29 N 178. 55 W 8. 7 8 Rat Islands 1957/03/09 14: 23 51. 29 N 175. 63 W 8. 6 9 Andreanof Islands 1938/11/10 20: 19 55. 48 N 158. 37 W 8. 2 Shumagin Islands 1812/02/07 09: 45 36. 5 N 89. 6 W 8. 0 New Madrid Area, MO 1899/09/10 21: 41 60. 0 N 140. 0 W 8. 0 Yakutat Bay 1986/05/07 22: 47 51. 33 N 174. 75 W 8. 0 Andreanof Islands 1857/01/09 16: 24 35. 7 N 120. 3 W 7. 9 Fort Tejon, CA 1868/04/03 02: 25 19. 0 N 155. 5 W 7. 9 Ka'u District, HI 1899/07/04 00: 22 60. 0 N 142. 0 W 7. 9 Near Cape Yakataga 1917/05/31 08: 47 54. 79 N 159. 12 W 7. 9 Shumagin Islands 1987/11/30 19: 23 58. 68 N 142. 79 W 7. 9 Gulf of Alaska 1996/06/10 04: 04 51. 56 N 177. 63 W 7. 9 Andreanof Islands 2002/11/03 22: 13 63. 51 N 147. 44 W 7. 9 Central Alaska 29

New Madrid Earthquakes Date Long. Mag. US Rank UTC Lat. Region 1812/02/07 09: 45 36. 5 N 89. 6 W 8. 0 5 New Madrid Area 1812/01/23 15: 00 36. 3 N 89. 6 W 7. 8 15 New Madrid Area 1811/12/16 08: 15 35. 6 N 90. 4 W 7. 7 23 New Madrid Area 1811/12/16 14: 15 35. 6 N 90. 4 W 7. 0 90 New Madrid Area 30

New Madrid Earthquakes 1811 -1812 31

New Madrid Fault Zone 32

Earthquake Motion 33

What worries us! 34

Alaska, 1964 35 Molnia

San Francisco 1906 USGS 36

Landslide Dam Sumatra 2004 -12 -24 USGS 37

San Francisco 1906 Even geologists are not immune! 38 Stanford

The Mid-Continent 39

New Madrid Fault Zone 40

New Madrid cf. San Francisco Steven Dutch, UWGB 41

Mercalli Scale • Giuseppe Mercalli, 1884 • Subjective • Measures damage • Modified to modern usage http: //en. wikipedia. org/wiki/Mercalli_intensity _scale 42

Richter Scale • Replaced Mercalli scale • Charles Richter, 1935 • Logarithmic measure of amplitude • Each number 10 x previous • Each number 30 x previous energy • Measured from instruments • Mostly objective http: //en. wikipedia. org/wiki/Richter_magnitud e_scale 43

Mercalli vs Richter (rough comparison) Richter 1. 0 – 3. 9 4. 0 – 4. 9 5. 0 – 5. 9 6. 0 – 6. 9 7. 0 and up Mercalli I II - III IV - V VI - VIII IX or higher 44

Probability In the next 50 years (USGS): Ø 1811 – 1812 magnitude (7. 5 – 8. 0) • 7 – 10 % Ø 6. 0 or greater • 25 – 40% 45

In Oklahoma • Expected (mb 6. 0): – Mercalli IV to V • Likely (mb 6. 6): – Mercalli V to VI • Possible (mb 7. 0): – Mercalli VI to VII • Worst-case (mb 7. 4): – Mercalli VII to VIII 46

Expected (6. 0) • • Intensity IV to V Felt by all, few or no injuries Rumbling, thunderous sounds Described as "strong" Hung objects swung, small objects shift Trees, buildings sway Vibrations like light truck Plaster cracked 47

Likely (6. 6) • • Worse in eastern Oklahoma Some structural damage Many run outside; few minor injuries Trees, bushes, buildings shaken strongly Objects off shelf; large furniture disturbed Plaster falls, chimneys cracked Small church bells ring 48

Possible (7. 0) • • Similar to 5. 6 in Prague, Nov. 2011 Reaction important (drop, cover, hold on) General alarm and fright; injuries probable Free-standing masonry walls crack Well-built structures damaged Tall chimneys broken Landslides; springs and wells change 49

Worst case (7. 4) • • Panic widespread, injuries common Reaction critical (drop, cover, hold on) Free-standing walls & external masonry fall Ordinary, substantial buildings damaged Waves seen on ground surface Telephones out of service Chimneys, factory stacks, monuments fall 50

Preparation • • http: //www. ready. gov/earthquakes Don't panic – look at the probabilities! Locate safe areas (doorways, safe-room) Upgrade construction practices Maintain structures Train and drill, especially for responders Tornadoes are far more deadly in OK Infrastructure not likely to be badly hurt 51

Haiti, 2010 • • 7. 0 on Richter scale 36 aftershocks > 4. 5 in 24 hrs 6. 1 aftershock on Jan. 20 th About 100, 000 dead & 300, 000 injured About 1 million homeless 250, 000 residences & 30, 000 businesses Most infrastructure destroyed or inoperable • Excellent world-wide response 52

Haiti, 2010 USGS 53

Haiti, 2010 Major earthquake and main aftershock Washington Post 54

Haiti, 2010 The fault NASA 55

Haiti, 2010 Damage assessment 56

Haiti, 2010 Port-au-Prince 57

Haiti, 2010 Presidential Palace 58

Haiti, 2010 59

Haiti, 2010 60

Haiti, 2010 Refugees CTV 61

Haiti, 2010 Brazilian Refugee Camp 62

Haiti, 2010 US Navy 63

Chile, 2010 • • • 2010 -2 -27 @ 06: 34 Z (03: 34 L) Magnitude 8. 8, #5 since 1900 Shortened day by 1. 26 s? About 500 dead 93% of country without power 64

Chile, 2010 • • • Subduction zone Concepcion 3 m W Santiago 24 cm W Buenos Aires 4 cm Seiches in Lake Ponchartrain 65

Chile, 2010 66

Chile, 2010 67

Japan, March 2011 Location (offshore) 68

Japan, March 2011 Tsunami height 69

Tsunami Intensity Wikipedia 70

Japan, March 2011 The tsunami did the most damage 71

Japan, March 2011 Entire cities were destroyed 72

Japan, March 2011 Even animals suffered: a petrel on Midway 73

Earthquakes Comparing Japan with Haiti shows the effect of concentration of population and quality of infrastructure Japan, March 2011 Haiti, January 2010 Magnitude 9. 0 7. 0 Deaths 15, 854 (most tsunami) 100, 000 (? ? ) Injured 26, 992 300, 000 Destruction 125, 000 buildings 280, 000 buildings 74

Sumatra 2004 -12 -24 75

Sumatra, 2004 -12 -24 76

Questions? 78