Tsunami inundation and sediment transport in a sediment-limited embayment on American Samoa

Abstract Field observations and numerical simulations are used to explore tsunami inundation and sediment transport in an embayment (Fagafue Bay) on the north side of Tutuila, American Samoa during the 29 September 2009 South Pacific tsunami. Field observations of the nearshore bathymetry and topography, tsunami flow depth and sediment deposition, and extent of movable sandy sediment remaining on the beach were collected during two field surveys approximately two and five weeks after the tsunami. Onshore measurements of flow depth at forty-eight locations indicate the wave inundated almost 250 m onshore with a depth exceeding 7 m locally. The tsunami deposited patchy areas of sediment up to 0.2 m thick interspersed with a thin dusting (

[1]  Leo C. van Rijn,et al.  Unified View of Sediment Transport by Currents and Waves. II: Suspended Transport , 2007 .

[2]  D. Pritchard,et al.  Modelling the sedimentary signature of long waves on coasts: implications for tsunami reconstruction , 2008 .

[3]  D. Walstra,et al.  Unified View of Sediment Transport by Currents and Waves. IV: Application of Morphodynamic Model , 2007 .

[4]  I. Foster,et al.  Reconstructing the pattern and depth of flow onshore in a palaeotsunami from associated deposits , 2007 .

[5]  L. Rijn.  Principles of sediment transport in rivers, estuaries and coastal seas , 1993 .

[6]  Bruce E. Jaffe,et al.  A simple model for calculating tsunami flow speed from tsunami deposits , 2007 .

[7]  E. Okal,et al.  Field Survey of the Samoa Tsunami of 29 September 2009 , 2010 .

[8]  H. Naruse,et al.  THICKNESS AND GRAIN-SIZE DISTRIBUTION OF INDIAN OCEAN TSUNAMI DEPOSITS AT KHAO LAK AND PHRA THONG ISLAND, SOUTH-WESTERN THAILAND , 2008 .

[9]  J. Goff,et al.  Hydrodynamic implications of textural trends in sand deposits of the 2004 tsunami in Sri Lanka , 2008 .

[10]  Dawn J. Wright,et al.  Derivation and Integration of Shallow-Water Bathymetry: Implications for Coastal Terrain Modeling and Subsequent Analyses , 2008 .

[11]  Per A. Madsen,et al.  Run-up of tsunamis and long waves in terms of surf-similarity , 2008 .

[12]  Y. Igarashi,et al.  Nine unusually large tsunami deposits from the past 4000 years at Kiritappu marsh along the southern Kuril Trench , 2007 .

[13]  D. Vatvani,et al.  Tsunami inundation and sediment transport in vicinity of coastal mangrove forest , 2007 .

[14]  Christopher A. Gomez,et al.  Tsunamis as geomorphic crises: Lessons from the December 26, 2004 tsunami in Lhok Nga, West Banda Aceh (Sumatra, Indonesia) , 2009 .

[15]  M. Oppenheimer,et al.  Coral reefs reduce tsunami impact in model simulations , 2006 .

[16]  Bruce E. Jaffe,et al.  Erosion and Sedimentation from the 17 July, 1998 Papua New Guinea Tsunami , 2003 .

[17]  Benjamin De Coster,et al.  Reconstruction of Tsunami Inland Propagation on December 26, 2004 in Banda Aceh, Indonesia, through Field Investigations , 2009 .

[18]  G. Stelling,et al.  Development and validation of a three-dimensional morphological model , 2004 .

[19]  Guus S. Stelling,et al.  A staggered conservative scheme for every Froude number in rapidly varied shallow water flows , 2003 .

[20]  N. Tanaka,et al.  Effect of open gap in coastal forest on tsunami run-up—investigations by experiment and numerical simulation , 2009 .

[21]  Harry Yeh,et al.  Tsunami run-up and draw-down on a plane beach , 2003, Journal of Fluid Mechanics.

[22]  V. R. Schneider,et al.  GUIDE FOR SELECTING MANNING'S ROUGHNESS COEFFICIENTS FOR NATURAL CHANNELS AND FLOOD PLAINS , 1989 .

[23]  Y. Nishimura,et al.  Sedimentary deposits of the 26 December 2004 tsunami on the northwest coast of Aceh, Indonesia , 2006 .

[24]  Y. Tsuji,et al.  Tsunamiites - Features and Implications , 2011 .

[25]  G. Stelling,et al.  On the approximation of horizontal gradients in sigma co‐ordinates for bathymetry with steep bottom slopes , 1994 .

[26]  L. Rijn.  Unified view of sediment transport by currents and waves. I: Initiation of motion, bed roughness, and bed-load transport , 2007 .

[27]  Brian G. McAdoo,et al.  Landward fining from multiple sources in a sand sheet deposited by the 1929 Grand Banks tsunami, Newfoundland , 2007 .

[28]  B. F. Atwater,et al.  Evidence for Great Holocene Earthquakes Along the Outer Coast of Washington State , 1987, Science.

[29]  C. Synolakis,et al.  The run-up of N-waves on sloping beaches , 1994, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[30]  Tadepalli,et al.  Model for the Leading Waves of Tsunamis. , 1996, Physical review letters.