JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSIMULATION OF A WORST CASETSUNAMI SCENARIO FROM THE
MANILA TRENCH TO VIETNAM
Nguyen Hong Phuong, Vu Ha Phuong, Pham The Truyen
Earthquake Information and Tsunami Warning Centre
Institute of Geophysics, VASTNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANOUTLINE

 Earthquake -Tsunami Hazards inVietnam
 Source modeling Simulation results
 Applications
 ConclusionsNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPAN

EARTHQUAKE – TSUNAMI HAZARDS•The largest earthquakes incountry: 3-1 historical (in the 14thcentury)- 2 recorded:-Dien Bien 1935 (M=6.7) andTuan Giao 1983 (M=6.8)• Offshore volcanic
earthquake 1923 (M=6.1).
• No records of historicaltsunamis, no official data on
damage and casualties

Seismotectonic map of Vietnam and adjacent sea areas
17 – 19 JUNE, 2013Nguyễn Hồng Phương
Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANEARTHQUAKE – TSUNAMI HAZARDSDue to its location, theVietnamese coast canhardly be affected bydestructive tsunamis,
originated in thecentral Pacific Ocean,from the sea of Japanand East China sea innortheast side and evenfrom the mega
subduction zones as theSundaland and thePhilippines.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPAN

EARTHQUAKE – TSUNAMI HAZARDS
However, thetsunami threats
might comefrom inside theEast Vietnamsea.

EastVietnamSeaPhilippineSeaSuluSea
CelebesSeaNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPAN

EARTHQUAKE – TSUNAMI HAZARDS
Based on the analysisof tectonic featureand geodynamic
characteristics ofregional faults
systems in the South
East Asia, 9 sourcezones capable ofgenerating tsunamis
affecting Vietnamese
coast were delineatedin the South China
Sea and adjacent sea
areas.

EastVietnam
Sea

Philippine
Sea

Sulu
Sea
CelebesSeaNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

the Vietnamese coast
has a SYMPOSIUMspecific situationONas ifSEISMIC
it is “blocked”
inside theEast Vietnam sea,
is surroundedJOINT
HAZARDASSESSMENT– which
SENDAI,
JAPAN by Chinese continen

EARTHQUAKE – TSUNAMI HAZARDS
Among the tsunami source zones defined, the Manila Trench source, west of thePhilippines is considered as the most dangerous for the Vietnamese coast. The recent
research results show that the maximum expected earthquake magnitude for theManila Trench source zone may reach to the value of Mw = 8.7, and it takes
approximately 2 hours for a tsunami from this source zone to hit the Vietnamese coastat the earliest.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSOURCE MODELING•

Vu Thanh Ca et al (2008) calculated 25 tsunami scenarios generated in theSouth China sea in order to investigate the impact to the Vietnamese coasts.

•The MOST model and a two – segment source model were used forsimulation.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSOURCE MODELING•In this study, we create a worst-case scenario of tsunami earthquake
excited by Manila Trench megathrust and assess the impact to theVietnamese coast.

•The Manila Trend source is modified on the basis of published updated
data and reasearch results in the region.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSOURCE MODELING

After Hsu et al (2012).
Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSOURCE MODELING

After Bautista et al (2001)

After Tso-Ren Wu et al (2009)Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSOURCE MODELING

After Kusnowidjaja Megawati et al (2009)Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSOURCE MODELINGThe Manila Trench worst case scenario’s source model was createdassuming a 6-segments fault zone which is capable for a Mw9.3 tsunami
generating earthquake. Parameters of each segment is listed bellow.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSIMULATIONThe numerical approach is applied to this study. The well validated open
source code, COMCOT (Cornell Multi-grid Coupled Tsunami Model), ischosen to perform the simulation.
The COMCOT model is capable of solving both linear and nonlinear
shallow water equations in the spherical and Cartesian coordinate systems. The
nested grid system can provide tsunami simulations in both deep-water andnear-shore coastal regions. The COMCOT model also provides the moving
boundary algorithm to simulate the tsunami inundation (Philip L. –F. Liu et al,1998).

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSIMULATION
To estimate the maximum wave heights at different places along theVietnamese coast, four grid layers are adopted and referred as Grids 1, 2, 3A,and 3B. Finer grid layers, Grids 3A and 3B, are placed in the areas of the twocoastal cities Da Nang and Nha Trang, respectively.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Hazards Assessment

Maximum free-surface elevation on Grid 1
17 – 19 JUNE, 2013Nguyễn Hồng Phương
Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Hazards Assessment

Maximum free-surface elevation on Grid 2 (Central Vietnam coast)Nguyễn Hồng Phương
17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Hazards Assessment

Wave heights maps calculated for Da Nang city (left) and Nha Trang city (right)Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Hazards Assessment
Sea level station

LongLatHòn Dáu_Hải Phòng

106.818300

20.665300

Giao Thủy_Nam Định106.559000

20.158600

Cửa Lò – Nghệ An

105.756000

18.824500

Đồng Hới – Quảng Bình106.668000

17.479900

Đà Nẵng108.250000

16.075000

Hội An108.432000

15.877900

Núi Thành – Quảng Nam

108.800000

15.488600Nghĩa An – Quảng Ngãi108.920000

15.118900

Quy Nhơn 2

109.303000

13.774900

Tuy Hòa

109.379000

13.083200

Nha Trang

109.198500

12.239400

Ninh Thuận

109.027000

11.410000

Vũng Tầu

107.083800

10.319700

104.850000

8.545000(Mũi Nghinh Phong)Cà MauLocation of the sea level stations along the coast
17 – 19 JUNE, 2013Nguyễn Hồng Phương
Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Hazards AssessmentNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Hazards AssessmentNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Database Development
A field trip was organized to collect data on
built-environment and population in Nha
Trang city.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Database DevelopmentNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Database Development
Head-up digitizing the building layer of the Nha Trang city using Google Earthimage.

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Database Development
Create a GIS building inventory database for the study areaNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Vulnerability and Risk Assessment

Built Environment
vulnerability map ofNha Trang cityNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Vulnerability and Risk Assessment
Population
vulnerability mapof Nha Trang:

during day timeand night timeNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Vulnerability and Risk Assessment

Risk map

Inundation map
17 – 19 JUNE, 2013Nguyễn Hồng Phương
Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Response and evacuation Planning

Tsunami shelters mapfor Nha Trang cityNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Response and evacuation Planning

Map of tsunami evacuation zones

Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANRESULTS AND APPLICATION
Response and evacuation PlanningNguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANCONCLUSIONSIn this study, we create a worst-case scenario of tsunami earthquake
excited by Manila Trench mega-thrust and assess the impact to the Vietnamese
coast. The source parameters are defined based on the models proposed by TsoRen Wu et al (2009) and Megawati K. et al (2009). The earthquake magnitude,Mw, is assumed to be 9.3 generated on the Manila Trench. The tsunami
propagation and inundation were numerically computed by using the COMCOT
open source code.
We focus the discussion in Central Vietnam coastal regions, andcarefully describe the maximum tsunami wave heights around two coastal cities,
Da Nang and Nha Trang. In Central Vietnam coast, the maximum tsunami wave
high of 22 m is observed at the coast of Quang Ngai province. The maximum
wave height is 14 m recorded at the coast of Da Nang city and is 12 m at thecoast of Nha Trang city. It might be concluded that the tsunami hazards from
Manila Trench source are devastating to Vietnamese coast, especially to theCentral Vietnam coast.
The simulation results can be used for the tsunami hazards/risk
assessment as well as warning and response purposes for the coastal zones of theNguyễn Hồng Phươngcoutry.
17 – 19 JUNE, 2013

Institute of Geophysics

JOINT SYMPOSIUM ON SEISMIC HAZARD ASSESSMENT – SENDAI, JAPANSIMULATION OF A WORST CASETSUNAMI SCENARIO FROM THE
MANILA TRENCH TO VIETNAM
Nguyen Hong Phuong, Vu Ha Phuong, Pham The Truyen
Earthquake Information and Tsunami Warning Centre
Institute of Geophysics, VASTTHANK YOU !
Nguyễn Hồng Phương

17 – 19 JUNE, 2013

Institute of Geophysics