Historical Earthquakes: Personal Comments
Willie Lee (Feb. 21, 2011)
"... old seismograms, if properly interpreted,
provide invaluable information on earthquakes in
the past, and every effort should be made to
save them, regardless of their quality, from
possible loss and to make copies in an easily
readable form."
Hiroo Kanamori (1988)
Some Milestones in Seismology
 1880: First effective seismographs (Ewing-Gray-Milne).
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1896: BAAS Committee on Seismology (Milne global network).
1901: Geophysical Inst. at Göttingen (Wiechert seismograph).
1903: International Association of Seismology (now IASPEI).
1906: Electromagnetic seismograph developed by Galitzin.
1930s: Benioff seismometers and strain seismograph.
1949: Seismicity of the Earth (Gutenberg & Richter) published.
1963: World-wide Standardized Seis. Network (WWSSN).
1964: International Seismological Centre (ISC).
1970s: Digital era began; Moment tensor inversion;
IASPEI/Unesco Historical Seismogram Filming Project.
 1991: IRIS Data Management Center.
John Milne (1850-1913):
Founding Father of Seismology
Two Seismology Pioneers: Fusakichi Omori
(1868-1923), & Emil Wiechert (1861-1928)
Prince Boris Galitzin (1862-1916) and the
Galitzin electromagnetic seismograph
Milne Seismogram (at Kew):
No damping, low sensitivity, & poor time resolution.
Wiechert Seismogram (at Göttingen):
Smoked paper records are difficult to scan.
Galitzin and Benioff Seismograms:
High sensitivity and photographic recording.
Galitzin seismograms: from ~1910, but hard to find;
Benioff seismograms: from ~1932
Two Definitions of Historical Earthquakes
• Any earthquake occurred from the beginning of the
instrumental era (~ 1882) to the beginning of the WWSSN
era (~ 1963). This definition was used in the "Historical
Seismogram Filming Project", and in the book "Historical
Seismograms and Earthquakes of the World", edited by W. H.
K. Lee, H. Meyers, and K. Shimazaki, Academic Press, San
Diego, 1988, 513 pp.
• Any earthquake occurred before 1900 (or before the first
global seismic network around 1900), as used in the Historical
Earthquake Catalog Component of the Global Earthquake
Model (GEM) initiative ( http://www.globalquakemodel.org/ )
A Modern Earthquake Database for Taiwan? (1)
• Any probabilistic seismic hazard analysis (PSHA) requires a
reliable database of earthquake source parameters that are
derived by modern methods of data processing and analysis
using instrumental data (seismic, geodetic, etc.), historical
records, and field observations of earthquake effects
(intensities from damage, fault ruptures, etc.).
• Like in the global case, many Taiwan earthquake catalogs &
databases exist, but a reliable and uniform earthquake database of Taiwan is not available from 1600 to the present.
• There are several compilations of historical earthquakes
(before 1900) of Taiwan, but none had used the modern
techniques as advocated by E. Guidoboni and J. Ebel,
Earthquakes and Tsunamis in the Past: A guide to
techniques in historical seismology, Cambridge Univ. Press,
2009.
A Modern Earthquake Database for Taiwan? (2)
• In 1898, a Gray-Milne seismograph and an Omori tromometer
were established at the Taihoku Meteorological Observatory.
• Knowing the distribution and capabilities of seismographic
stations in Taiwan and its surrounding regions, it is possible to
study Taiwan earthquakes with the following approximate
magnitude (M) cutoff:
• 1898 – 1903: M > 7.5 Seismographs also at Manila (1884),
Osaka (1901), & Zikawei (1903).
• 1904 – 1920: M > 6.5 Taiwan local stations & Wiechert
seismographs.
• 1921 – 1963: M > 6
Galitzin & sensitive seismographs.
• 1963 – 1974: M > 5.5 WWSSN stations.
• 1975 – 1989: M > 4 .5 Telemetered seismic network at IES.
• 1990 – Now: M > 3.5 Digital seismic networks (CWB & IES
in Taiwan, GDSN worldwide, etc.)
Difficulties in Studying Historical Earthquakes
in Taiwan
• Difficulties in collecting and interpreting historical records of
Taiwan earthquakes before 1900.
• Collecting seismograms and time/amplitude/period data for
Taiwan earthquakes from 1900 to 1962 will be costly.
• Locating earthquakes before 1963 is difficult because station
distribution is often poor, seismographs are not
standardized, and station clocks often have large errors.
Grid-search location software helps, but requires judgments.
• Computing uniform earthquake magnitudes is a challenge.
• Waveform modeling helps in constraining source location,
focal mechanism & quake size, but requires a lot of work.
Studying Historical Quakes: Some Resources
 The SeismoArchives website: http://www.iris.edu/seismo/
contains scanned seismograms, station information, and
some useful books and papers.
 Frechet, J., M. Meghraoui, and M. Stucchi (Editors) (2008).
Historical Seismology: Interdisciplinary studies of past and
recent earthquakes. Springer, Berlin.
 Kanamori, H., L. Rivera, and W.H.K. Lee (2010). Historical
seismograms for unravelling a mysterious earthquake: The
1907 Sumatra Earthquake. Geophys. J. Int., 183, 358-374.
http://www.gps.caltech.edu/people/kanamori/publications
 Lee, W.H.K., H. Meyers, and K. Shimazaki (Editors) (1988).
Historical Seismograms and Earthquakes of the World,
Academic Press, San Diego. Free download at:
http://www.iris.edu/seismo/info/publications/Lee1988.pdf