Presentacin de PowerPoint

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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 7.- Future Plans
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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 7.- Future Plans
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Subduction zone between Nazca and South American
Tectonic Plates
SOUTH AMERICAN PLATE
NAZCA PLATE
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Big Earthquakes in Chile XIX-XX Century

• Tsunami generation depends
• Earthquake's magnitude
• Distribution rupture zone
• Orientation rupture zone
• Rupture dimensions
• Epicentre location
• Vertical 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 7.- Future Plans
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Length of Dislocation Zones Coastal Tsunami
Earthquakes along the chilean coast 1500 2005
period
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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 AND SPREADING IS
  LOW IN DEEP WATER.
• ENERGY DISSIPATION IS EXPECTED TO BE IMPORTANT
  IN SHALLOW WATERS.

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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 7.- Future Plans
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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
• - Reflected
• - Trapped
• - Focused
• Tsunamis entering bay can be subjected to
  resonant conditions, resulting in a substantial
  increase of wave heights at particular coastal
  points.

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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 7.- Future Plans
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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 7.- Future Plans
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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 used1, 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 Universitys 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
Modelling Nested coarse to fine rectangular
grids of differents resolution
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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 7.- Future Plans
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Numerical Modelling Results
QUINTERO BAY- GRID 3 TRIDIMENSIONAL VIEW
QUINTERO BAY- GRID 3 (The scale is deformed)
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Numerical Modelling Results
Seismic parameters of the 8th july 1730 earthquake
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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
Ventanas
Quintero bay
Quintero bay
Península Los Molles
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 7.- Future Plans
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CITSU Project Tsunami Inundation Maps A
planning tool
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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
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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 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.
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Components of Tsunami Forecast
Future Plans
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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
Finite element modelling grid
Variable size triangular grids size varies
with depth and strong depth contrasts
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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
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
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