Sri Lanka Earthquake and Tsunami Warning Training Program

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Sri Lanka Earthquake Tsunami Warning Training
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Session I.1 Introduction to Earthquake Science
A Historical Perspective April 3, 2006 CETRAC,
Sri Lanka
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Sri Lanka Earthquake Tsunami Warning Training
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• Topics covered in this talk
• Global Mosaic of Earthquakes
• Milestones in Seismology
• Historically Significant Earthquakes
• Statistical Features of Seismicity

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Sri Lanka Earthquake Tsunami Warning Training
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Sri Lanka Earthquake Tsunami Warning Training
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Sri Lanka Earthquake Tsunami Warning Training
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Sri Lanka Earthquake Tsunami Warning Training
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Milestones in Seismology
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.
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Sri Lanka Earthquake Tsunami Warning Training
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Map of Earthquake Locations by Mallet, 1868.
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Sri Lanka Earthquake Tsunami Warning Training
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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 Earths core by
studying seismic waves. 1909 Andrija
Mohorovicic discovers the moho discontinuity,
which is the boundary between Earths crust
and mantle. 1935 Charles Richter develops the
magnitude scale (the so-called Richters
magnitude scale), which is used for determining
the size of earthquakes as applied in Southern
California.
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Sri Lanka Earthquake Tsunami Warning Training
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Milestones in Seismology
1936 Inge Lehmann from Denmark discovers the
Earths 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.
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Sri Lanka Earthquake Tsunami Warning Training
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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.
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Sri Lanka Earthquake Tsunami Warning Training
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Earthquakes As Natural Disasters
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Sri Lanka Earthquake Tsunami Warning Training
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• 10 Most Destructive Natural Disasters in the Last
  100 years
• 1970 Hurricane (Bangladesh) 300,000
• 2004 Earthquake Tsunami (Indonesia) 278,000
• 1976 Earthquake (China) 250,000
• 1991 Hurricane (Bangladesh) 140,000
• 1970 Earthquake/landslide (Peru) 60,000
• 1990 Earthquake (Iran) 50,000
• 1988 Earthquake (Armenia) 25,000
• 1978 Earthquake (Iran) 25,000
• 1995 Volcanic eruption (Columbia) 23,000
• 1976 Earthquake (Guatemala) 22,000

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Sri Lanka Earthquake Tsunami Warning Training
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• 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

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

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San Francisco Liquefaction
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Sri Lanka Earthquake Tsunami Warning Training
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• Anchorage
• March 27, 1964 536 PM
• 8.6M, 800 km-long rupture
• 120 casualties from tsunami
• Largest earthquake in US history
• Initiation of US earthquake hazard program

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Anchorage, 1964 Surface Rupture
Fault trace
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Sri Lanka Earthquake Tsunami Warning Training
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Anchorage, 1964 Landslide Effect
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Sri Lanka Earthquake Tsunami Warning Training
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Anchorage, 1964 Tsunami
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Sri Lanka Earthquake Tsunami Warning Training
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• Mexico City
• September 18, 1985 717 AM
• 7.8M, 4 billion damage
• 8,000 casualties, 30,000 injured, 50,000
  homeless
• Severe impacts in center of city (soil
  amplification)

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Sri Lanka Earthquake Tsunami Warning Training
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Sri Lanka Earthquake Tsunami Warning Training
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• Armenia or Spitak Earthquake
• December 7, 1988 1141 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
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Sri Lanka Earthquake Tsunami Warning Training
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• Loma Prieta, the World Series Quake
• October 17, 1989 504 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

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Sri Lanka Earthquake Tsunami Warning Training
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• Northridge
• January 17, 1994 431 AM
• 6.7M, 20 billion damage
• 57 deaths, thousands injured
• 24,000 buildings damaged

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Sri Lanka Earthquake Tsunami Warning Training
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• Kobe, Japan
• January 17, 1995 546 AM
• 6.9M, 100 billion damage
• 5,300 casualties, 33,000 injured
• Amplification in filled land

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Kobe, Japan 1995 Damage to Transportation System
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Earthquake Statistics
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Sri Lanka Earthquake Tsunami Warning Training
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Earthquake Statistics
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Earthquake Statistics