Oceanography The Official Magazine of
The Oceanography Society
Volume 32 Issue 04

View Issue TOC
Volume 32, No. 4
Pages 56 - 65


Typhoon-Forced Waves Around a Western Pacific Island Nation

Sophia T. Merrifield Travis A. SchramekSean CelonaAna Beatriz Villas BôasPatrick L. ColinEric J. Terrill
Article Abstract

Over the last decade, the Pacific island nation of Palau, situated at 7°N, has had a number of close encounters with Category 4 and 5 typhoons, including the named storms Bopha, Haiyan, and Lan in 2012, 2013, and 2017, respectively. Although historically, due to its low latitude location, typhoon activity has been rare in Palau, it was in the direct path of typhoons Bopha and Haiyan, which caused extensive wind damage, reef destruction, and wave-driven inundation across the island group. Typhoon Lan formed and stalled northwest of the main island group, generating large swell that damaged the coral communities on the western barrier reefs of Palau. Wave gauges deployed in water depths of 9–17 m around the island group captured strong gradients in the surface wave field during each typhoon. Significant wave height measured by the pressure gauges varied by as much as 5 m, highlighting the importance of coastline and reef geometry in wave transformation and shadowing. WAVEWATCH III model hindcasts are used to interpret the observed gradients in the data sets, characterize the offshore incident wave direction during the storms, and describe shadowing of swell by the island chain. Coral damage that occurred during the storms is linked to the relative orientation of the coastline and the dominant swell wave direction. This study establishes a framework for identifying vulnerable coastline areas that may benefit Palau’s preparedness efforts and informs resolution requirements for applying regional wave models to support risk assessments at islands with complex shorelines and steep bathymetry.


Merrifield, S.T., T.A. Schramek, S. Celona, A.B. Villas Bôas, P.L. Colin, and E.J. Terrill. 2019. Typhoon-forced waves around a western Pacific island nation. Oceanography 32(4):56–65, https://doi.org/10.5670/oceanog.2019.411.


Ardhuin, F., E. Rogers, A.V. Babanin, J.F. Filipot, R. Magne, A. Roland, A. van der Westhuysen, P. Queffeulou, J.-M. Lefevre, L. Aoui, and F. Collard. 2010. Semiempirical dissipation source functions for ocean waves: Part I. Definition, calibration, and validation. Journal of Physical Oceanography 40(9):1,917–1,941, https://doi.org/​10.1175/2010JPO4324.1.

Becker, J.M., M.A. Merrifield, and H. Yoon. 2016. Infragravity waves on fringing reefs in the tropical Pacific: Dynamic setup. Journal of Geophysical Research 121(5):3,010–3,028, https://doi.org/​10.1002/2015JC011516.

Bishop, C.T., and M.A. Donelan. 1987. Measuring waves with pressure transducers. Coastal Engineering 11(4):309–328, https://doi.org/​10.1016/0378-3839(87)90031-7.

Black, P.G., E.A. D’Asaro, W.M. Drennan, J.R. French, P.P. Niler, T.B. Sanford, E.J. Terrill, E.W. Walsh, and J.A. Zhang. 2007. Air-sea exchange in hurricanes. Bulletin of the American Meteorological Society 88(3):357–374, https://doi.org/10.1175/BAMS-88-3-357.

Colin, P.L. 2018. Thalassodendron ciliatum (Cymodoceaceae) in Palau: Occurrence, typhoon impacts and changes over time. Botanica Marina 61(6):537–546, https://doi.org/10.1515/bot-2017-0079.

Colin, P.L., and S.J. Lindfield. 2019. Palau. Pp. 285–299 in Mesophotic Coral Ecosystems. Y. Loya, K.A. Puglise, and T.C.L. Bridge, eds, Springer International Publishing, https://doi.org/​10.1007/​978-3-319-92735-0_16.

CRRF (Coral Reef Research Foundation). 2014. A Summary of Palau’s Typhoon History 1945–2013. Technical Report, 17 pp., https://coralreefpalau.org/wp-content/uploads/2017/05/CRRF-Palau-Typhoon-History-2014-1.pdf.

Gawehn, M., A. van Dongeren, A. van Rooijen, C.D. Storlazzi, O.M. Cheriton, and A. Reniers. 2016. Identification and classification of very low frequency waves on a coral reef flat. Journal of Geophysical Research 121(10):7,560–7,574, https://doi.org/​10.1002/2016JC011834.

Gouezo, M., Y. Golbuu, R. van Woesik, L. Rehm, S. Koshiba, and C. Doropoulos. 2015. Impact of two sequential super typhoons on coral reef communities in Palau. Marine Ecology Progress Series 540:73–85, https://doi.org/10.3354/meps11518.

Herbers, T.H.C., S. Elgar, and R.T. Guza. 1995. Generation and propagation of infragravity waves. Journal of Geophysical Research 100(C12):24,863–24,872, https://doi.org/10.1029/95JC02680.

Holthuijsen, L.H. 2010. Waves in Oceanic and Coastal Waters. Cambridge University Press, 404 pp., https://doi.org/10.1017/CBO9780511618536.

Holthuijsen, L.H., M.D. Powell, and J.D. Pietrzak. 2012. Wind and waves in extreme hurricanes. Journal of Geophysical Research 117(C9), https://doi.org/​10.1029/2012JC007983.

King, A.D., D.J. Karoly, and G.J. van Oldenborgh. 2016. Climate change and El Niño increase likelihood of Indonesian heat and drought. Bulletin of the American Meteorological Society 97(12):S113–S117, https://doi.org/10.1175/BAMS-D-16-0164.1.

Kubota, H., R. Shirooka, T. Ushiyama, T. Chuda, S. Iwasaki, and K. Takeuchi. 2005. Seasonal variations of precipitation properties associated with the monsoon over Palau in the western Pacific. Journal of Hydrometeorology 6(4):518–531, https://doi.org/​10.1175/JHM432.1.

Longuet-Higgins, M.S. 1952. On the statistical distribution of the height of sea waves. Journal of Marine Research 11:245–266.

Monismith, S.G. 2007. Hydrodynamics of coral reefs. Annual Review of Fluid Mechanics 39:37–55, https://doi.org/10.1146/annurev.fluid.38.050304.092125.

NCEI (National Centers for Environmental Information). 2006. 2-minute gridded global relief data (ETOPO2) v2. National Oceanic and Atmospheric Administration, https://www.ngdc.noaa.gov/mgg/global/etopo2.html

Péquignet, A.C.N., J.M. Becker, M.A. Merrifield, and J. Aucan. 2009. Forcing of resonant modes on a fringing reef during tropical storm Man-Yi. Geophysical Research Letters 36(3), https://doi.org/​10.1029/​2008GL036259.

Roeber, V., and J.D. Bricker. 2015. Destructive tsunami-​like wave generated by surf beat over a coral reef during Typhoon Haiyan. Nature Communications 6:7854.

Schramek, T.A., P.L. Colin, M.A. Merrifield, and E.J. Terrill. 2018. Depth-dependent thermal stress around corals in the tropical Pacific Ocean. Geophysical Research Letters 45(18):9,739–9,747, https://doi.org/10.1029/2018GL078782.

Shimozono, T., Y. Tajima, A.B. Kennedy, H. Nobuoka, J. Sasaki, and S. Sato. 2015. Combined infragravity wave and sea-swell runup over fringing reefs by super typhoon Haiyan. Journal of Geophysical Research 120(6):4,463–4,486, https://doi.org/​10.1002/2015JC010760.

WAVEWATCH III Development Group. 2016. User manual and system documentation of WAVEWATCH III version 5.16. Technical Note 329, NOAA/NWS/NCEP/MMAB, College Park, MD, 326 pp.

Copyright & Usage

This is an open access article made available under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately, provide a link to the Creative Commons license, and indicate the changes that were made to the original content. Images, animations, videos, or other third-party material used in articles are included in the Creative Commons license unless indicated otherwise in a credit line to the material. If the material is not included in the article’s Creative Commons license, users will need to obtain permission directly from the license holder to reproduce the material.