Transcript HYDROGRAPHIC AND OCEANOGRAPHIC SERVICE OF THE CHILEAN NAVY (SHOA) “Numerical simulation for tsunami

Tsunami Hazard Mitigation and
Risk Assessment Workshop
Santiago, Chile
29 - 30 September 2005
HYDROGRAPHIC AND
OCEANOGRAPHIC SERVICE OF THE
CHILEAN NAVY (SHOA)
“Numerical simulation for tsunami
inundation maps in Chile”
Dante Gutierrez
National Tsunami Warning System
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Table of contents
1.- Introduction
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
2
7.- Future Plans
Table of contents
1.- Introduction
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
3
7.- Future Plans
Subduction zone between Nazca and
South American Tectonic Plates
NAZCA PLATE
SOUTH AMERICAN PLATE
Sismos superficiales
Sismos intermedios
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Sismos profundos
-15S
1868
-20S
Big
Earthquakes in
Chile
XIX-XX Century
1877
1995
-25S
1922
-30S
1943
1971
1906
1985
-35S
1928
1939
Tsunami generation depends:-40S
1960
 Earthquake's magnitude
 Distribution rupture zone
 Orientation rupture zone
 Rupture dimensions
 Epicentre location
 Vertical displacement
-45S
-50S
-55S
-80W
5
1949
-75W
-70W
-65W
-60W
Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
6
7.- Future Plans
Años
1868
2000
1877
1784
1900
1768
1995
1543
20°
1800
1715
1687
1700
1582
1604
1600
1513
1500
1922
1971
1943
1985
1905
1822
1730
1928
1835
1751
1657
1975
20° 80°W
S
1575
60°
20°
30°
30°
40°
40°
50°
50°
45°
S
1960
1837
40°
1737
1500 – 2005 period
35°
1570
Coastal Tsunami
Earthquakes along
the chilean coast
1647
1575
1880
30°
1894
1859
1849
1796
Length of
Dislocation Zones
1819
25°
90°W
53°W
Antártica Chilena
60°
7
60°
Tsunamis Effects in Chile
ARICA: AUGUST 13, 1868
ARICA: MAY 9, 1877
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Tsunamis Effects in Chile
COQUIMBO: NOVEMBER 11, 1922
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Tsunamis Effects in Chile
CORRAL: MAY 22, 1960
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Tsunamis Effects in Chile
CORRAL: MAY 22, 1960
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Tsunami Propagation
• PROPAGATION IN OPEN OCEAN
 TSUNAMI WAVES UNDERGO CHANGES DUE TO
REFRACTION DURING PROPAGATION AS IF THEY
WERE SHALLOW WATER WAVES.
 IN
COMPARISON,
ENERGY
LOSSES
SPREADING IS LOW IN DEEP WATER.
 ENERGY DISSIPATION IS EXPECTED
IMPORTANT IN SHALLOW WATERS.
TO
AND
BE
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Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
13
7.- Future Plans
Tsunami Propagation
 When tsunami waves propagate into coastal areas they
interact with the coastal bathymetric and topographic
features in a variety of ways:
- Reflection
- Shoaling and Refraction
 Tsunamis may locally be:
BAY
Wave-rays divergence
- Reflected
- Trapped
- Focused
Tsunamis entering bay can
be subjected to resonant
PENINSULA
convergence
conditions, resulting in a Wave-rays
substantial
increase of wave
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heights at particular coastal points.
Tsunami Propagation
TSUNAMI SPEED
TSUNAMI SPEED
TSUNAMI SPEED
SEA LEVEL
DEPTH
DEPTH
DEPTH
SEA FLOOR
DISPLACEMENT
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Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
16
7.- Future Plans
Numerical Modelling
Modelling the inundation
 Various
Wave type – breaking waves, non-breaking
waves, rapid rise & fall and bore
Roughness factor
 Require
Nearshore batimetry to at least ~1 m contour
interval
Nearshore topography to at least 5 m contour
interval
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Numerical Modelling
Powerful tool for:
-
Hazard assessment.
Worst case scenarios.
Understanding past events.
Forecasting the effects of potential future events.
Real-time forecasting of wave-heights from distant
source events
- Developing database of potential local source events
for real time local event forecasting.
• Selection of appropriate sources critical for local tsunamis.
• Use of appropriate modelling technique, boundary
conditions, approximations, critical case, etc.
• Calibration with historical events/tide gauge records
advisable.
• Good bathymetry and near-shore topography essential.
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Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
19
7.- Future Plans
CITSU PROJECT
Processing of Tsunami Inundation Maps for
the Chilean Coast
 Since
1996 NTWS has been producing
inundation charts for the main ports to help
the Civil and Navy Authorities to emergency
plans and mitigate the effects of tsunamis.
 A Numerical simulation technique to
modelling of the potential effects of tsunamis
has been used in order to evaluating tsunami
risk in the chilean harbours.
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Numerical Simulation of Tsunamis
IUGG/IOC TIME PROJECT
TUNAMI-N code was used[1], a numerical facility
for the modelling of near field tsunamis,
developed by Dr. Shuto in Tohoku University,
Japan, based on a leap-frog finite difference
scheme
and
includes
the
generation,
propagation and run-up of tsunami waves by
means of the shallow water wave theory.
[1] TUNAMI-N is the acronym for Tohoku University’s Numerical Analysis Model for Investigation
of Near-Field Tsunamis.
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Numerical Simulation of Tsunamis
Numerical Modelling:
Modelling the source – Earthquakes




Assume instantaneous uplift
Vertical movement usually most important
Horizontal movement occasionally important
The seismic events were selected from
historical records of earthquakes occurred in
Chile
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Numerical Simulation of Tsunamis
Modelling the tsunami
Long Wave equations
 Coriolis term – near field events can be dropped
 Bottom friction term – important in shallow water
 Non-linear terms – important in shallow water
Numerical modelling technique
 Finite Difference (rectangular grid)
 Grid density increases with decreasing water depth
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Numerical Simulation of Tsunamis
Modelling thechnique:
Finite Difference
GRID D
93x93m
Modelling
Nested coarse to fine
rectangular grids of
GRID C 278x278m
differents resolution
GRID B 833x833m
GRID A 2498x2498m (partial view)
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Numerical Simulation of Tsunamis
Rectangular
grid A of 81”
resolution
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Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
26
7.- Future Plans
Numerical Modelling Results
QUINTERO BAY- GRID 3”
TRIDIMENSIONAL VIEW
N
QUINTERO BAY- GRID 3”
(The scale is deformed)
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Numerical Modelling Results
Seismic parameters of the 8th july 1730 earthquake
PARAMETER
ESTIMATION
South-western corner of the
rupture zone
36°S 73°W
Grid A (23,23)
Pardo, Comte and Eisemberg, 1989
34°S
Grid A (67,112)
Nishenko, 1985
350 – 450 km
Kausel, 1985
550 km
Comte et al., 1986 ; Pardo, Comte and Eisemberg, 1989
Length (L)
Width (W)
100-150 km
Nishenko, 1985
Dislocation (u)
6-8 m
Nishenko, 1985
Depth (H)
15 – 40 km
Lorca, 2001
Strike Angle ()
N10°E
SHOA, 1999
Direction of dislocation ()
90°
SHOA, 1999
Dip angle ()
18°
SHOA, 1999
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Numerical Modelling Results
Distribution of uplift and subsidence in the source
region (grid 81”). 1730 Tsunami Earthquake.
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Numerical Modelling Results
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Numerical Modelling Results
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Numerical Modelling Results
3D Numerical Simulation in Quintero bay, Chile
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Numerical Modelling Results
To facilitate the production of the tsunami
flooding chart, a smooth line is interpolated
between grid results according to the small
scale topographic features not described in the
93 x 93 m grid.
Ventanas
Quintero bay
Península
Los Molles
Ventanas
Quintero bay
Península
Los Molles
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Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts:
Hazard mitigation, prevention, preparedness
and response plans in Chile
34
7.- Future Plans
CITSU Project
Tsunami Inundation Maps : A planning tool
.
.
Arica
Arica
Iquique
Tocopilla - Mejillones
Antofagasta
Antofagasta
Taltal
Chañaral – Caldera - Huasco
.
.
La Serena – Coquimbo
Los Vilos - Papudo
Quintero - Viña del Mar – Valparaíso
Algarrobo - San Antonio
1997
1998
1999
2000
2001
2002
2003
2004
Total
2
2
4
7
3
4
3
3
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Constitución - Penco - Tomé
Lirquén - Talcahuano
San Vicente – Coronel - Lebu
Corral
Ancud
Coquimbo
Valparaíso
.
.
Talcahuano
Puerto Montt
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Tsunami Inundation Charts
(Main ports along the Chilean coast)
Estimated Tsunami Inundation
at Iquique, Chile, based on
numerical model results.
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San Antonio
Harbour
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Graphic and Photographic Reports
Flooding Areas
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Development of hazard mitigation, prevention,
preparedness and response plans in Chile
 Using CITSU project maps Arica, Antofagasta, Viña
del Mar Emergency Offices have designed a Hazard
and Resources Map for each tsunami risk zone.
 Tsunami Emergency and Evacuation Plans prepare
and educate the population for alert, coordinate,
evaluate, resolve and take plans decision integrated to
government and local emergency agencies actions, so
that the population knows what to do according to the
area it lives.
 Arica and Antofagasta have implemented a system of
alarm of Tsunami with sirens of early alert.
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Tsunami signals in
the Viña del Mar city
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Tsunami signals in
Arica city
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Tsunami sirens located in Antofagasta and Arica ports
Table of contents
1.- Introduction.
- Conceptual Remarks and Tsunami Generation
- Historical Tsunamis in Chile
2.- Tsunami Propagation
3.- Numerical Modelling
4.- CITSU Project:
Numerical Simulation of Tsunamis
5.- Numerical Modelling Results: Examples
6.- Tsunami Inundation Charts
- Hazard mitigation, prevention, preparedness
and response plans in Chile
43
7.- Future Plans
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Future Plans
 Within the operative context, NTWS don't
have the technical operability yet to estimate
in real time the potential impact of tsunami
waves arriving to the chilean coast.
Design and implement a numerical model for
the forecast of run-ups of near and far field
events, in order to estimate the potential
impact of tsunamis on the chilean coast,
based on real time data of sea level obtained
from stations located close to the source and
from DART buoys.
45
Future Plans
initial seismic data
Pre-computed Forecast
Database of Linear
Propagation Solutions
tsunameter data
Components of Tsunami Forecast
46
Future Plans
 Develop of inundation maps for others coastal
cities of Chile (CITSU II project)
 Include far field simulation and wave
propagation of tsunami earthquakes toward
insular areas of Chile
 Improve the modelling technique, through
Phase – II of TIME project :
• Using better resolution with finite elements
• Stability of numerical computation for extreme
seismic parameters and border conditions in
the grids boundary
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Future Plans
-30
DEPTH
8000
6000
5000
4000
3000
2000
1500
1000
750
500
250
100
50
0
-40
latitude
Finite
element
modelling
grid
-50
Variable size triangular grids:
-60
size varies with depth and
strong depth contrasts
160
170
180
longitude
190
200
210
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Future Plans
Tsunamis far field simulation
1700AD Cascadia earthquake (probable magnitude ~9) Trans-Pacific tsunami propagation – Satake et al
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Recent Tsunamis
Jan 1, 1996
Nov 14, 1994
Jul 12, 1993
Feb 21, 1996
Oct 9, 1995
Sulawesi Is.
Mindoro Is.
Okushiri, Japan
Northern Peru
Jalisco, Mexico
Wave height: 3.4 m Wave height: 7 m Wave height: 31 m Wave height: 11 m
Wave height: 5 m
Victims: 9
Victims: 49
Victims: 239
Victims: 12
Victims: 1
Feb 17, 1996
Jul 17, 1998
Sep 2, 1992
Irian Jaya
Dec 12, 1992
Papua New Guinea
Nicaragua
Wave height : 7.7 m Wave height : 15 m Wave height : 10 m
Flores Is.
Victims: 161
Wave height: 26 m
Victims: >2200
Victims: 170
Victims: >1000
Nov 26, 1999
Jun 23, 2001
Jan 3, 2002
Jun 2, 1994
Southern Peru
Vanuatu Is.
Java
Wave height: 2 m
Wave height: 14 m
Wave height: 3 m
Victims: 50
Without victims
Victims: 238
Dec 26, 2004
Sumatra
Wave height: 10 m
Victims: 360.000+
When will the next Tsunami
Earthquakes happen in Chile?
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Tsunami Hazard Mitigation and
Risk Assessment Workshop
Santiago, Chile
29 - 30 September 2005
END OF SLIDE - SHOW
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