Tsunami Intensity: Tsunami Intensity: A Valuable Parameter of Multiple A Valuable Parameter of Multiple

UsefulnessUsefulness

Papadopoulos G.A., Daskalaki E., Fokaefs A.

Institute of GeodynamicsNational Observatory of Athens, Greece

papadop@gein.noa.gr

Size of a natural event is traditionally measured by the intensity that is the impact of the event

Exampleso Beaufort 12-point scale for windo Saffir-Simpson 5-point scale for typhoonso Mercalli-Sieberg 12-point scale for earthquakeso EMS-98 new 12-point scale for earthquakes

Intensity of natural phenomenaIntensity of natural phenomena

Modern measure of the size of a natural event is magnitude which expresses the energy of the event

Exampleso Richter and moment-magnitude scales for earthquakeso Newhall-Self 8-point scale for volcanic eruptionso Iida scale for tsunamis

Magnitude of natural phenomenaMagnitude of natural phenomena

Tsunami ScalesTsunami Scales Type of TsunamiType of Tsunami Analogy to Earthquake ScalesAnalogy to Earthquake Scales

Intensity Scales

Sieberg [1927] primitive 6-point intensityscale

early intensity scales

Ambraseys [1962] improved 6-point intensityscale

improved intensityscales

Shuto [2001] developed 6-point intensity scale developed intensityscales

Papadopoulos & Imamura [2001]

new 12-point intensity scale new EMS ’92 and ’9812-point intensity scale

Magnitude Scales

Imamura - Iida[40’s, 50’s & 60’s]

primitive magnitude scale local Richter magnitudescale

Soloviev [1970] primitive magnitude scale local Richter magnitude

Abe [80’s & 90’s] magnitude scale surface-wave magnitude scale

Murty - Loomis [1980] magnitude scale moment – magnitude scale

o Size of a tsunami based on the macroscopic observation of tsunami’s effect on humans, objects, including various size of marine vessels and buildings

o What factors control the disastrous effects of the tsunami?- humans, - effects on objects (e.g. vessels of variable size),- nature (e.g. ground erosion),- damage to buildings.

Tsunami intensityTsunami intensity

o Incorporates twelve divisions o Is consistent with several 12-grade seismic intensity scales.

(Papadopoulos & Imamura, 2001)

a. Independent from physical parametersb. Sensitive to the small difference in tsunami effectsc. Detailed description of each division by taking into account all possible

tsunami impacts on human and natural environment

12-point tsunami intensity scale12-point tsunami intensity scale

Empirical correlation between the intensity K, introduced by Empirical correlation between the intensity K, introduced by Papadopoulos & Imamura (2001) and the quantities H and i Papadopoulos & Imamura (2001) and the quantities H and i

introduced in formula by Shuto (1993)introduced in formula by Shuto (1993)

K H (m) i

I-V <1.0 0VI 2.0 1

VII-VIII 4.0 2IX-X 8.0 3XI 16.0 4XII 32.0 5

The 12-point scale has been used in:The 12-point scale has been used in:

o Indian Ocean after the tsunami of 2004 (Narayan J.P. et al., Pure & Applied Geophysics, 163, 1279p., 2006; Rossetto T. et al., Natural Hazards, 2006; Maheshwari et al., Earthquake Spectra, 23/III, S475p.; Chang et al., Earthquake Spectra, 23/III, S863p.)

o Black Sea (Yalciner A. et al., J. Geophys. Res., 109, C12023p., 2004)o Mediterranean Sea (Tinti, S. et al., Marine Geology, 225, 311p., 2006)o Azores Islands (Andrade C, J. Volcanol. & Geoth. Res., 156, 172p., 2006) o Australia (Dominey-Howes, D., Marine Geology, 239, 99p., 2007)o Indonesia (Lavinge et al., Nat. Hazards Earth Syst. Sci., 177p., 7, 2007)o Portugal (Baptista et al., NHESS, 2009)

Further Presentation of the 12-scale can Further Presentation of the 12-scale can be found in the following books:be found in the following books:

o Β. Levin & Μ. Nosov: Physics of Tsunamis & Kindred Phenomena in Ocean, Moscow, Janus-K, 2005; Physics of Tsunamis, Springer, 2009.

o Tsunami Glossary from the Intergovernmental Oceanographic Commission of UNESCO and the International Tsunami Information Centre, USA, 20p, 2006.

o M. Woods & Μ.B. Woods: Tsunamis, Lerner Publ. Comp., Minneapolis, 2007.

o E. Guidoboni & J.E. Ebel: Earthquakes & Tsunamis in the Past: A guide to techniques in historical seismology, 2009.

Possible applications of the new 12-point Possible applications of the new 12-point tsunami intensity scaletsunami intensity scale

o Revision of tsunami catalogueso Mapping the geographical distribution of the impact of past

tsunamiso Description of the tsunami impact by intensity isolineso Construction of empirical attenuation laws of the tsunami impacto Tsunami statistics

Observation points: 206

Indian Ocean 2004 IntensitiesIndian Ocean 2004 Intensities

Observation points: 53

Indian Ocean 2004 IntensitiesIndian Ocean 2004 Intensities

Observation points: 149

Indian Ocean 2004 IntensitiesIndian Ocean 2004 Intensities

Tsunamicity of Greece: Tsunamicity of Greece: the highest in the Euro-Mediterranean region

Papadopoulos & Fokaefs, 2005

9 July 19569 July 1956earthquake M=7.5 tsunami: 15-20m

The tsunami source 9The tsunami source 9thth July 1956 event July 1956 event

VI-VIII

VI-VIII

V

IV

III

Wave attenuation of 9Wave attenuation of 9thth July 1956 July 1956

At = 86.41x Δ-0.8208

r2 = 0.54

0

2

4

6

8

10

12

14

16

0 100 200 300 400

Δ(km)

At (m)

3 largest K's / 50 Km

K = 7.2144e-0.0028Δ

R2 = 0.743

02

46

810

0 100 200 300 400

Δ (Km)

K

Attenuation law /epicentral distances

3 largest intensities K per 50km / epicentral distances

↘ Magnitude-frequency or G-R relation (Gutenberg and Richter, 1944) extensively used in seismology to describe the exponential decrease of the event frequency, Nc, with the increase of the event magnitude, M:

Earthquake StatisticsEarthquake Statistics

bMaNc log 20/10/2005 - 21/11/2005

Log N = -1.83 ML + 8.45

R2 = 0.995

0.00

1.00

2.00

3.00

2.0 3.0 4.0 5.0

M L

log N

o Intensity-frequency → equivalent to the magnitude-frequency or G-R relation (Gutenberg & Richter, 1944) used in seismology:

o Describes the exponential degree of the event frequency with the decrease of the event size

o Excluding frequencies of events with K ≥ 3:

Application of the tsunami statistics: Application of the tsunami statistics: West Hellenic ArcWest Hellenic Arc

bKaN cc log

KNc 3.03.3log

From it comes out that the mean repeat time, TK , of events of intensity equal to or larger than K is:

or the mean yearly rate of

occurrence is

K Tk=10bK-a r =1/Tk last event2 4 0.23646 18983 9 0.11581 19834 18 0.05672 18995 36 0.02778 20006 73 0.01361 18667 150 0.00666 18678 306 0.00326 16129 626 0.00160 -

10 1277 0.00078 365

t (years) Kmax

10 3.250 5.5

100 6.41000 9.7

maximum intensity, Kmax, which is the most probable to be observed within time interval t is given by the

expression

abKKT

10

KTr

1

b

taK

logmax

bKaN cc log

Poissonian StatisticsPoissonian Statistics

o From the mean yearly rate of tsunami occurrence we calculated the probability, , to observe at least one tsunami of intensity K equal to or larger than a given value within particular time interval, t.

o The probability to observe x events in t years is while the

probability to observe at least one tsunami event in t years is

t (years) K≥2 K≥4 K≥6 K≥8 K≥101 0.21 0.06 0.01 0.003 0.001

10 0.91 0.43 0.13 0.03 0.01100 1.00 0.99 0.74 0.28 0.08

1000 1.00 1.00 1.00 0.96 0.54

!)(

))((

x

exP

xrtrt

t

tt xPxP )0(1)1(

txP )1(

Seismic damage: e.g. Bucharest, 4 March, 1997, M= 7.4

SAFER Project, EU-FP6, 2009, Partner NIEP, Romania

intensity map shake map

Possible future application for tsunamisPossible future application for tsunamis

o Construction of expected tsunami damage maps in terms of tsunami intensity in analogy to expected seismic damage

o This requires: - inundation zone from numerical simulation- Vulnerability analysis- Damage scenario

Thank you for your attentionThank you for your attention