1. Sri Lanka Earthquake & Tsunami Warning Training Program Session I.1 Introduction to Earthquake Science: A Historical Perspective April 3, 2006 CETRAC, Sri Lanka

2. Sri Lanka Earthquake & Tsunami Warning Training Program Topics covered in this talk: Global Mosaic of Earthquakes Milestones in Seismology Historically Significant Earthquakes Statistical Features of Seismicity

3. Sri Lanka Earthquake & Tsunami Warning Training Program

6. Ca 132 BC: First seismoscope, showing the direction of incoming earthquake waves, is developed in China. 1875: The first seismometer is invented by Filippo Cecchi in Italy. 1889: A distant earthquake is recorded instrumentally for the first time. The recording is made in Potsdam, Germany of a Japanese earthquake. Milestones in Seismology

7. Sri Lanka Earthquake & Tsunami Warning Training Program Map of Earthquake Locations by Mallet, 1868.

8. Sri Lanka Earthquake & Tsunami Warning Training Program Milestones in Seismology 1892: John Milne develops a seismometer, which is installed at approximately 40 observatories around the world. This is the beginning of global earthquake monitoring. 1906: Richard Oldham discovers Earth’s core by studying seismic waves. 1909: Andrija Mohorovicic discovers the moho discontinuity, which is the boundary between Earth’s crust and mantle. 1935: Charles Richter develops the magnitude scale (the so-called “Richter’s magnitude scale”), which is used for determining the size of earthquakes as applied in Southern California.

9. Sri Lanka Earthquake & Tsunami Warning Training Program 1936: Inge Lehmann from Denmark discovers the Earth’s inner core. 1961: The World-Wide Standardized Seismic Network (WWSSN) is established for monitoring both earthquakes and nuclear testing. WWSSN is later overtaken by IRIS. 1966: Keiiti Aki defines seismic moment, which is a physical measure of the magnitude of an earthquake. 1969-72: Apollo astronauts place a seismometer on the Moon, and the first "moonquakes" are registered. 1977: Hiroo Kanamori establishes the moment magnitude scale, which is a measure of earthquake magnitude based on seismic moment. Milestones in Seismology

10. Sri Lanka Earthquake & Tsunami Warning Training Program 1984: The US National Science Foundation and US Geological Survey provide funding for a new, digital seismic network, the GSN. to replace the aging WWSSN. 1996: The International Data Center is established in Vienna and seismic monitoring is done through the International Monitoring System (IMS). The IMS makes use of many stations of the GSN.

11. Sri Lanka Earthquake & Tsunami Warning Training Program Earthquakes As Natural Disasters

12. Sri Lanka Earthquake & Tsunami Warning Training Program 10 Most Destructive Natural Disasters in the Last 100 years: 1.1970 Hurricane (Bangladesh): 300,000 2.2004 Earthquake & Tsunami (Indonesia): 278,000 3.1976 Earthquake (China): 250,000 4.1991 Hurricane (Bangladesh): 140,000 5.1970: Earthquake/landslide (Peru): 60,000 6.1990: Earthquake (Iran): 50,000 7.1988: Earthquake (Armenia): 25,000 8.1978: Earthquake (Iran): 25,000 9.1995: Volcanic eruption (Columbia): 23,000 10.1976: Earthquake: (Guatemala): 22,000

13. Sri Lanka Earthquake & Tsunami Warning Training Program Historically Significant Earthquakes San Francisco 1906 Anchorage, Alaska 1964 Mexico City 1985 Armenia 1988 Loma Prieta (San Francisco) 1989 Northridge (Los Angeles) 1994 Kobe, Japan 1995

14. Sri Lanka Earthquake & Tsunami Warning Training Program San Francisco April 18, 1906, early morning 8.3M, 750-2,500 casualties First major urban earthquake The Great Fire

15. Sri Lanka Earthquake & Tsunami Warning Training Program San Francisco Liquefaction

16. Sri Lanka Earthquake & Tsunami Warning Training Program Anchorage March 27, 1964 5:36 PM 8.6M, 800 km-long rupture 120 casualties from tsunami Largest earthquake in US history Initiation of US earthquake hazard program

17. Sri Lanka Earthquake & Tsunami Warning Training Program Fault trace Anchorage, 1964– Surface Rupture

18. Sri Lanka Earthquake & Tsunami Warning Training Program Anchorage, 1964– Landslide Effect

19. Sri Lanka Earthquake & Tsunami Warning Training Program Anchorage, 1964– Tsunami

20. Sri Lanka Earthquake & Tsunami Warning Training Program Mexico City September 18, 1985 7:17 AM 7.8M, $4 billion damage 8,000 casualties, 30,000 injured, 50,000 homeless Severe impacts in center of city (soil amplification)

21. Sri Lanka Earthquake & Tsunami Warning Training Program

22. Armenia or “Spitak” Earthquake December 7, 1988 11:41 AM 6.8M, $14 billion damage 25,000 casualties, 15,000 injured, 100,000 homeless Most severe event in USSR in 40 years Surface Rupture

23. Sri Lanka Earthquake & Tsunami Warning Training Program Loma Prieta, the “World Series Quake” October 17, 1989 5:04 PM 7.1M, $7 billion damage 63 casualties, 3,700 injured, 12,000 displaced San Andreas Fault, ~50 km south of San Francisco Severe liquefaction

24. Sri Lanka Earthquake & Tsunami Warning Training Program Northridge January 17, 1994 4:31 AM 6.7M, $20 billion damage 57 deaths, thousands injured 24,000 buildings damaged

25. Sri Lanka Earthquake & Tsunami Warning Training Program

26. Kobe, Japan January 17, 1995 5:46 AM 6.9M, $100 billion damage 5,300 casualties, 33,000 injured Amplification in filled land

27. Sri Lanka Earthquake & Tsunami Warning Training Program Kobe, Japan 1995– Damage to Transportation System

28. Sri Lanka Earthquake & Tsunami Warning Training Program Earthquake Statistics

29. Sri Lanka Earthquake & Tsunami Warning Training Program Earthquake Statistics

30. Sri Lanka Earthquake & Tsunami Warning Training Program

31. Earthquake Statistics