3-2-3. Magnitude and Frequency of Earthquakes
• Epicenter & Hypocenter
http://earthquake.usgs.gov/learn/glossary/?term=epicen
ter
http://withfriendship.com/user/sathvi/epicenter.php
• Types of seismic waves
http://www.uwgb.edu/dutchs/earthsc202notes/quakes.htm
• Magnitudes
• Finding the Distance to the Epicenter and the Earthquake's
Magnitude
http://www.geo.mtu.edu/UPSeis/locating.html
• Richter Scale
https://vle.whs.bucks.sch.uk/mod/resource/view.php?id=13709
(MMS: modified magnitude scale)
http://jazinator.blogspot.kr/2014/02/a-magnitude-220-earthquake-star-wars.html
3-2-3. Earthquake Hazard
• Primary vs. secondary
• Primary – Directly from the shaking (causing rupture of the
surfaces and destruction of the structures)
• Secondary – From fire, flooding, tsunami, landslide etc.
• Depends on
•
•
•
•
•
Distance from the epicenter (or focus)
Magnitude
Rigidity of the ground
Resistance of a building against quake
Population
Relationship between near-surface earth material and amplificati
on of shaking during a seismic event
http://www.ga.gov.au/image_cache/GA8210.gif
The part of the Cypress freeway structure in Oakland, California, that stood on soft mud (dashed red line) collapsed in th
e 1989 Loma Prieta earthquake, killing 42 people. Adjacent parts of the structure (solid red) that were built on firmer gro
und remained standing. Seismograms (upper right) show that the shaking was especially severe in the soft mud. (Photo
graph by Lloyd S. Cluff)
http://pubs.usgs.gov/fs/1999/fs151-99/
From top left to bottom left (clockwise): Sichuan, China (2008), Kobe, Japan (1995), Sansalvador, Elsalvador (2001), Niikata, J
apan (1964)
15 dealiest earthquakes
Rank
Death toll
Location
Date
1.
830,000
Shaanxi earthquake China
January 23, 1556
2.
650,000–779,000
Tangshan earthquake China
July 28, 1976
3.
273,400
Haiyuan earthquake China
December 16, 1920
4.
316,000
Haiti earthquake Haiti
January 12, 2010
5.
250,000–300,000
Antioch earthquake Byzantine Empire (now Turkey)
May 526
6.
260,000
Antioch earthquake Roman Empire (now Turkey)
December 13, 115
7.
230,000
Indian Ocean earthquake Indonesia
December 26, 2004
8.
230,000
Aleppo earthquake Zengid dynasty (now Syria)
October 11, 1138
9.
200,000
Hongdong earthquake Yuan Dynasty (now China)
September 17, 1303
10.
200,000
Damghan earthquake Abbasid Caliphate (now Iran)
December 22, 856
11.
200,000
Tabriz earthquake Iran
January 8, 1780
12.
170,000
Udaipur earthquake India
896
13.
150,000
Ardabil earthquake Abbasid Caliphate (now Iran)
March 23, 893
14.
142,807
Great Kanto earthquake Japan
September 1, 1923
15.
130,000
Aleppo earthquake Byzantine Empire (now Syria)
November 29, 533