1. NEOWAVE For last two decades, researchers are aware of the importance of wave dispersion, bore

propagation, and wave breaking in tsunami numerical modeling (simulation). More recent

models can address either one or two of the three processes.

We developed a new tsunami numerical model, NEOWAVE (Non-hydrostatic Evolution of

Ocean WAVE), which can handle wave dispersion, bore propagation, and wave breaking

using an alternate theoretical and numerical formulation [1].

We further extended NEOWAVE to model tsunami evolution processes from its generation,

propagation to run-up, through implementation of following methods and schemes [2]:

● Dynamic Sea Floor Deformation

To account for detailed earthquake rupture processes in tsunami generation.

● Spherical Grid

To properly model basin-wide tsunami propagation.

● Grid Refinement Scheme (Two-way Grid Nesting)

To use appropriate grid resolution for each tsunami processes.

2. Tsunami Modeling

3. Future Studies and Applications

The 2009 Samoa Earthquake occurred near the Tonga trench.

The resulting tsunami reached the shores of Tutuila Island,

American Samoa with a maximum elevation of 12 m. Post-

tsunami surveys show significant variation of the run-up and

impact between adjacent beachfront villages [3,4]. We

reconstruct the 2009 Samoa Tsunami using NEOWAVE to

examine these disparities in the recorded data [2].

NEOWAVE uses a coupled, 4-level grid nesting system to

model the entire tsunami evolution in one computation (FIG.2)

considering wave dispersion, wave breaking and bore

propagation. NOEWAVE successfully reproduce the run-up

/inundation in Pago Pago Harbor, which shows significant

east-west variation of tsunami impact (FIG.3).

FIG.1. Breaking wave over fringing reef. NEOWAVE reproduces

energetic wave breaking and won the 2009 Benchmark

Challenge at ISEC Workshop in Oregon among 10 tsunami

models.

Yoshiki Yamazaki and Kwok Fai Cheung

Department of Ocean and Resources Engineering, University of Hawaii at Manoa

FIG.2. Modeling the 2009 Samoa

Tsunami using NEOWAVE at 30 min after

the earthquake. (a) Tsunami propagation

over the Samoa islands (2000-m gird). (b)

Tsunami propagation over American

Samoa (250-m grid) using non-rectangle

domain. (c) Tsunami transformation

around Tutuila Islands (50-m grid) using

non-rectangle domain. (d) Run-

up/Inundation in Pago Pago Harbor (10-

m grid).

FIG.3. Run-up and inundation in Pago

Pago Harbor. , NEOWAVE;

(white), recorded inundation [3]; ○(white),

recorded run-up [3,4]; ○(blue), recorded

flow depth plus land elevation [3,4].

Recent and Future Tsunami Researches The 2009 Samoa Tsunami - Resonance analysis due to insular shelf [5].

- Investigation of tsunami generation mechanism.

The 2010 Chile Tsunami - Resonance analysis over continental shelf [6].

- Modeling water level and velocity at Hawaiian

water.

- Modeling run-up/inundation along Chile coast.

The 2010 Mentawai Tsunami - Earthquake and Tsunami source study [7].

The 1700 Cascadia Tsunami - Tsunami impact on coastal infrastructure [8].

FIG.5. Modeling the 2010 Chile

Tsunami. (a) Wave propagation

across southeastern Pacific. (b) Waveforms and amplitude spectra at DART buoys. , NEOWAVE; , recorded data.

Applications Tsunami Inundation Mapping - Hawaii, Northwest Hawaiian Islands,

American Samoa, Western Samoa, the

US Gulf coasts, Puerto Rico, and Chile.

Storm Surge and Wave Modeling - Pacific Islands, and the US East coasts.

Tsunami Modeling Workshop - Chile (FIG.4)

1. Yamazaki, Y., Kowalik, Z., and Cheung, K.F. (2009). Depth-integrated, non-hydrostatic model for wave breaking and run-up. International Journal for Numerical Methods in Fluids, 61(5), 473-497.

2. Yamazaki, Y., Cheung,K.F., and Kowalik, Z. (2010). Depth-integrated, non-hydrostatic model with grid nesting for tsunami generation, propagation and run-up. International Journal for Numerical Methods in Fluids, DOI: 10.1002/ftd.2485.

Development of Advanced Tsunami Model, NEOWAVE

3. Koshimura, S., Nishimura, Y., Nakamura, Y., Namegaya, Y., Fryer, G.J., Akapo, A., Kong, L.S., and Vargo, D. (2009) Field survey of the 2009 tsunami in American Samoa. EOS Transactions of the American Geophysical Union, 90(52), Fall Meeting Supplemental Abstruct U23F-07.

4.Okal, E.A., Fritz, H.M., Synolakis, C.E., Borrero, J.C., Weiss, R., Lynett, P.J., Titov, V.V., Foteinis, S., Jaffe, B.E., Liu, PLF, and Chan, I.C. (2010). Filed Survey of the Samoa Tsunami on 29 September 2009. Seismological Society of America, 81(4): 577-591.

5. Roeber, V., Yamazaki, Y., and Cheung, K.F. (2010). Resonance and impact of the 2009 Samoa Tsunami around Tutuila, American Samoa. Geophysical Research Letters, 37(21), L21604, doi: 10.1029/2010GL044419.

6. Yamazaki, Y., and Cheung, K.F. (2011). Shelf resonance and impact of near-field tsunami generated by the 2010 Chile Earthquake. Geophysical Research Letters, in review.

7. Lay, T., Ammon, C.J., Kanamori, H., Yamazaki, Y., and Cheung, K.F. (2011). The 25 October 2010 Mentawai tsunami earthquake (Mw 7.8) and the tsunami hazard presented by shallow megathrust ruptures. Geophysical Research Letters, in press.

8. Cheung, K.F., Wei, Y., Yamazaki, Y., and Yim, S.C. (2011). Modeling of 500-year tsunamis for probabilistic design of coastal infrastructure in the Pacific Northwest. Coastal Engineering, in review.

(a)

(b)

(a). Level-1 grid (2000m) (b). Level-2 grid (250m)

(c). Level-3 grid (50m) (d). Level-4 grid (10m)

Pago Pago Harbor

2009 Samoa Earthquake

Epicenter

FIG.4. NEOWAVE workshop at

University of Chile. We provided

the first time tsunami modeling

course in Chile. 17 researchers

from Chilean universities and

institutes participated in this

workshop.