Historical Data in Application to Tsunami Hazard and Risk Assessment

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Historical Data in Application to Tsunami Hazard
and Risk Assessment
V.GUSIAKOV
Tsunami Laboratory Institute of Computational
Mathematics and Mathematical Geophysics Siberian
Division Russian Academy of Sciences Email
gvk_at_sscc.ru
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Part I HISTORICAL CATALOGS AND DATABASES Part
II TSUNAMI RISK ASSESSMENT
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Distribution of the global tsunamigenic events
over validity index
Cause of Tsunami
Distribution of the tsunamigenic events over the
type of source
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Whole historical period
for XX century
Distribution of the events over the main
tsunamigenic regions
Distribution of the events over the main
tsunamigenic regions
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Comparative length of tsunami catalogs for the
main tsunamigenic regions
Regions Length of catalogs N of Evs N of Evs (I 1) Return period, years
PTWS 2054 (47BC 2008) 1277 475 4.3
IOTWS 285 (1722 2008) 80 70 4.1
CARTWS 515 (1498 2008) 113 100 5.1
NEAMTWS 4007 (2000BC-2008) 475 420 9.5
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Distribution of the Pacific tsunamigenic events
over time for the last 500 years
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A comparative length and completeness of
regional tsunami catalogs in the Pacific
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Table 1. List of historical trans-oceanic
tsunamis). MS surface wave magnitude, I
tsunami intensity on the Soloviev-Imamura scale,
HmaxNF maximum reported run-up in the near
field in m, HmaxFF maximum reported run-up in
the far field in m, FAT number of reported
fatalities due to tsunami.
Date and place MS I HmaxNF, m HmaxFF, m FAT
November 1, 1755 Lisbon November 7, 1837 Chile August 13, 1868 Chile February 3, 1923 Kamchatka April 1, 1946 Aleutians November 4, 1952 Kamchatka March 9, 1957 Aleutians May 22, 1960 Chile March 28, 1964 Alaska December 26, 2004 Sumatra 8.5 8.5 9.1 8.3 7.9 9.0 9.1 9.5 9.2 9.3 4.0 3.0 3.5 3.5 4.0 4.0 3.5 4.0 4.5 4.5 30.0 8.0 15.0 8.0 42.2 18.0 22.8 15.2 68.0 50.9 7.0 6.0 5.5 6.1 20.0 9.1 16.1 10.7 6.0 9.6 30,000 many 612 3 165 12,000 none 1,260 221 229,866
) Selected according to some formal criteria -
run-up height greater that 5 m at the distance
greater then 5,000 km from the source.
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Table 2. List of the historical tsunamis with
run-up greater than 50 m, sorted in order of
their Hmax value. MS surface wave magnitude,
I tsunami intensity on the Soloviev- Imamura
scale, m tsunami magnitude on the Iida scale,
Hmax maximum reported run-up in m, CAU - cause
of tsunami (T- tectonic, L landslide, V-
volcanic), FAT number of reported fatalities
due to tsunami.
Date and Place MS I m Hmax, m CAU FAT
July 10, 1958 Lituya Bay, Alaska 7.9 2.5 9.1 525 L 2
May 18 1980 Spirit Lake, WA, USA - 2.0 7.9 250 VL none
October 27, 1936 Lituya Bay, Alaska - 2.0 7.2 150 L unknown
1853-1854 Lituya Bay, Alaska - 2.0 6.9 120 L unknown
August 6, 1788 Sanak Is., Aleutians 8.0 4.0 6.5 88) T unknown
April 24, 1771 Ishigaki Is, Ryukuy 7.4 3.5 6.4 85 TL 13,486
February 17, 1674 Oma, Indonesia 8.0 4.0 6.3 80) T 2247
September 13, 1936 Loen, Norway - 2.0 6.1 70 L 4
March 28, 1964 Alaska 8.5 4.5 6.1 68 TL 115
October 17, 1737 Kamchatka 8.5 4.0 6.0 63) T unknown
April 7, 1934 Tafjord, Norway - 2.0 5.9 62 L 40
September 10, 1899 Yakutat, Alaska 8.6 3.5 5.9 60 TL unknown
May 21, 1792 Unzen volcano, Japan - 2.0 5.8 55 VL 4,300
December 26, 2004, Sumatra, Indonesia 8.8 4.5 5.7 51 T 229,866
) Run-up value is based on a single witness
report and, therefore, is not very reliable
.
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Table 3. List of largest seismically-induced
regional tsunamis. MS surface wave
magnitude, MW moment-magnitude, I tsunami
intensity on the Soloviev-Imamura scale, Hmax
maximum reported run-up in m, CAU - cause of
tsunami (T- tectonic, L landslide), FAT
number of reported fatalities due to tsunami
Date and Place MS MW I Hmax, m CAU FAT
July 9, 1586 Lima, Peru 8.5 - 3.5 26.0 T many
January 31 1605 Shikoku, Japan 8.0 - 3.5 30.0 T many
December 2, 1611 Sanriku, Japan 8.1 - 4.0 25.0 T 4,783
October 28, 1707 Nankaido, Japan 8.1 - 4.0 25.7 T 30,000
December 23, 1854 Nankaido, Japan 8.3 - 3.0 28.0 T 5,000
June 15, 1896 Sanriku, Japan 7.4 8.5 3.8 38.5 T 27,122
March 2, 1933 Sanriku, Japan 8.3 8.6 3.5 29.3 T 3,064
July 9, 1956 Aegean Sea 7.5 7.7 3.0 30.0 TL none
December 12 1992 Flores Sea 7.6 7.7 2.7 26.2 TL 2,200
July 12, 1993 Okushiri, Japan 7.6 7.7 3.1 31.7 T 198
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Table 4. List of largest historical volcanic
tsunamis. VEI volcaniuc explosion index, VOL
total volume of eruptive material in km3, Hmax
maximum reported run-up, I tsunami intensity
on the Soloviev-Imamura scale, FAT_EVE total
number of fatalities, FAT_TSU fatalities from
tsunami
Date and place VEI VOL, km3 Hmax, m I FAT_EVE FAT_TSU
1628 BC Santorini, Aegean Sea 416 Java, Indonesia 1452 Kuwae, Vanuatu July 31, 1640 Komagatake, Japan August 29, 1741 Oshima, Japan May 21, 1792 Unzen, Japan April 10, 1815 Tambora, Indonesia August 27, 1883 Krakatau, Indonesia March 13, 1888 Ritter, Bismark Sea August 4, 1928, Paluweh, Flores Sea 6 6 6 5 4 2 7 6 3 3 60-70 20-30 32-39 80-100 18-20 1-2 40-90 gt50 10-15 10 15 35-55 5-10 36-41 12-15 5-10 4.0 4.0 3.0 2.0 2.5 2.5 1.5 4.0 3.0 2.0 unknown unknown unknown 15,000 9,745 92,000 37,000 3,000 226 unknown unknown unknown 700 1,475 4,300 1,000 36,416 500 160
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I 3.55 Mw 27.1 (Chubarov, Gusiakov, 1985)
Dependence of tsunami intensity I on magnitudes
MS and Mw for the tsunamigenic earthquakes
occurred in the Pacific in 1900-1999
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Hmax
m log2Hmax
I ½ log2Hav
Hav
Typical distribution of tsunami run-up heights
along the coast calculated for seismic source
equivalent to a magnitude 7.5 submarine
earthquake for a model bottom relief typical
for Island arc regions
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I 3.55 Mw 27.1
Dependence of tsunami intensity I on magnitudes
MS and Mw for the tsunamigenic earthquakes
occurred in the Pacific in 1900-1999
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I 3.55 Mw 27.1
I(Mw) diagram for red, green and blue
tsunamigenic earthquakes occurred in the Pacific
in 1900-1998
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Over 84 of their fatalities occurred within the
first hour of propagation time. Another 12
fatalities occured within the second hour, with
the rest (4) occurring in the remaining time
(exceeding two hours).
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Part II TSUNAMI RISK ASSESSMENT
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General formula for calculation of tsunami risk is
R H V C, where R risk, H hazard, V
vulnerability, C- cost
In this formula, the ITDB can contribute to
calculation of H value, i.e. probability of
exceedence of any selected run-up value for a
given period of time

• Basic steps involved in the tsunami hazard
  calculation by this approach are
• Selection of a geographical area
• Retrieval of historical run-ups
• Calculation of the recurrence function
• Calculation of the hazard curve

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Visualization of the observed tsunami wave
heights in the Pacific (47 BC 2003)
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Tsunami Hazard Analysis Step 1 (selection of a
geographical area)
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Tsunami Hazard Analysis - Step 2 (retrieval of
the historical run-up data)
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Tsunami Hazard Analysis Step 3 (calculation of
the recurrence function)
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Tsunami Hazard Analysis Step 4 (calculation of
probability of exceedence)
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Map of degree of tsunami hazard for the Pacific,
divided into three categories low (blue),
medium (green) and high (red)
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Map of degree of tsunami hazard for the Atlantic
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Map of degree of tsunami hazard for the
Mediterranean
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Map of degree of tsunami hazard for the Indian
Ocean
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Conclusion 1
The intensity of seismically induced tsunamis is
mainly controlled by an earthquake magnitude and,
in general, is directly proportional to it.
Detailed study of historical data for the
instrumental period of available observations
(since 1900) shows, however, that the actual
scattering of tsunami intensity for earthquakes
with the same magnitude exceeds six grades on the
Soloviev-Imamura scale. That means than tsunami
amplitudes can differ by a factor of 60 for
earthquakes of the same magnitude, that makes
unreasonable an operational prediction of
expected tsunami height at the coast, based
solely on earthquake magnitude .
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Conclusion 2
Of all 2250 tsunamigenic events, only 223 (10)
tsunamis resulted in any fatalities, all others
were weak local events observable only in several
particular areas of the nearest coast. From these
223 deadly tsunamis, 213 (95) fall into the
category of local and regional events with most
damage and all fatalities limited to one-hour
propagation time. In total, they are responsible
for 426,000 (61) fatalities
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Conclusion 3
Ten trans-oceanic tsunamis that occurred in the
World Ocean during the last 250 years are
responsible for 274,000 (39) fatalities. Among
them, nearly 230,000 people were killed during
just one event the December 26, 2004 Indian
Ocean tsunami. All other trans-oceanic tsunamis
are responsible for 34,000 deaths or 5 of all
tsunami-related fatalities
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Conclusion 4
The study of the death toll for 10 most
destructive trans-oceanic tsunamis occurred in
the World Ocean during the last 250 years shows
that although the damaging impact of large
tsunamis can last up to 23-24 hours, over 84 of
their fatalities occurring within the first hour
of propagation time. Another 12 of fatalities
occur within the second hour, with the rest of
4 occurring at the remaining time (exceeding two
hours).
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Conclusion 5
There is a persistent need for any information
that predates or augments historically reported
and instrumentally measured past occurrence of
tsunamis. Geological data on paleotsunamis
therefore should be included in tsunami catalogs.
Only on the basis of integrity of all data
(instrumental, historical and geological) can we
study the time-space patterns of large tsunamis
and evaluate their long-term occurrence rates.
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The end