NOAA Technical Memorandum OAR PMEL-136 SCIENTIFIC AND TECHNICAL ISSUES IN TSUNAMI HAZARD ASSESSMENT OF NUCLEAR POWER PLANT SITES Science Review Working Group Pacific Marine Environmental Laboratory Seattle, WA Pacific Marine Environmental Laboratory Seattle, WA May 2007 UNITED STATES NATIONAL OCEANIC AND Office of Oceanic and DEPARTMENT OF COMMERCE ATMOSPHERIC ADMINISTRATION Atmospheric Research Carlos M. Gutierrez VADM Conrad C. Lautenbacher, Jr. Richard W. Spinrad Secretary Under Secretary for Oceans Assistant Administrator and Atmosphere/Administrator NOTICE from NOAA Mention of a commercial company or product does not constitute an endorsement by NOAA/OAR. Use of information from this publication concerning proprietary products or the tests of such prod- ucts for publicity or advertising purposes is not authorized. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration. Science Review Working Group: Frank Gonz´alez (Chair), NOAA Center For Tsunami Research, PMEL, Seattle, WA Eddie Bernard, NOAA Center for Tsunami Research, PMEL, Seattle, WA Paula Dunbar, NOAA National Geophysical Data Center, Boulder, CO Eric Geist, USGS Coastal and Marine Geology Division, Menlo Park, CA Bruce Jaffe, USGS Pacific Science Center, Santa Cruz, CA Utku Kˆano˘glu, Middle East Technical University, Ankara, Turkey Jacques Locat, Universit´e Laval, Quebec, Canada Harold Mofjeld, NOAA Center For Tsunami Research, PMEL, Seattle, WA Andrew Moore, Kent State University, Kent, OH Costas Synolakis, USC Tsunami Research Center, Los Angeles, CA Vasily Titov, NOAA Center For Tsunami Research, PMEL, Seattle, WA Robert Weiss, NOAA Center For Tsunami Research, PMEL, Seattle, WA This report should be cited as: Gonz´alez, F.I., E. Bernard, P. Dunbar, E. Geist, B. Jaffe, U. Kˆano˘glu, J. Locat, H. Mofjeld, A. Moore, C. Synolakis, V. Titov, and R. Weiss (Science Review Working Group) (2007): Scientific and technical issues in tsunami hazard assessment of nuclear power plant sites. NOAA Tech. Memo. OAR PMEL-136, Pacific Marine Environmental Laboratory, Seattle, WA, 125 pp. + appendices on CD. Contribution No. 3031 from NOAA/Pacific Marine Environmental Laboratory Also available from the National Technical Information Service (NTIS) (http://www.ntis.gov) ii Contents iii Contents ExecutiveSummary(EddieBernard)................ 1 1. Introduction (Frank Gonz´alez)................. 3 1.1 Background............................ 3 1.2 Relevant Federal AgenciesandPrograms........... 4 1.3 TsunamiCharacteristics..................... 4 1.4 Purpose, Scope, and Content of Report . 7 2. U.S.TsunamiOccurrences(PaulaDunbar)......... 9 2.1 NOAA/NGDCDataOverview................. 9 2.2 SourceMechanismStatistics.................. 9 2.3 DamageandDeaths....................... 9 2.4 RegionalandStateAnalysis................... 12 2.5 Seiches............................... 14 2.6 Recommendation......................... 14 3. Geologic Evidence of Tsunamis (Andrew Moore and Bruce Jaffe)................................ 15 3.1 PurposeandScope........................ 15 3.2 Definitions............................ 15 3.3 Deposits as Indicators of Past Tsunamis . 15 3.4 IdentificationofTsunamiDeposits............... 17 3.5 SearchMethods.......................... 21 3.6 Recommendation......................... 21 4. TsunamiSources(EricGeistandJacquesLocat)...... 23 4.1 Earthquakes............................ 23 4.1.1 Source types and environment of occurrence . 23 4.1.2 Generation mechanism and methodology . 24 4.1.3 Sourceparameters................... 26 4.2 Submarine and Subaerial Landslides . 31 4.2.1 Source types and environment of occurrence . 31 4.2.2 Generation mechanism and methodology—submarine landslides........................ 34 4.2.3 Source parameters—submarine landslides . 37 4.2.4 Generation mechanism and methodology—Subaerial landslides........................ 40 4.2.5 Source parameters—subaerial landslides . 40 4.2.6 Icefalls......................... 41 4.3 Volcanoes............................. 41 4.3.1 Source types and environment of occurrence . 41 4.3.2 Generation mechanism by type of volcanogenic source 42 4.4 Recommendations........................ 43 5. TsunamiDynamics(VasilyTitov)............... 45 5.1 Generation............................ 45 5.1.1 Co-seismicdeformationsources............ 45 5.1.2 Landslidetsunamisource............... 49 5.2 Propagation . 49 5.3 Inundation . 54 5.3.1 Runup......................... 55 5.3.2 Drawdown....................... 58 5.3.3 Duration of inundation . 59 5.3.4 Bores.......................... 60 iv Contents 5.4 Theory and Implementation of Long-Wave Models . 61 5.4.1 Mathematicalformulation............... 61 5.4.2 Moving boundary condition . 63 5.4.3 Solutionmethods................... 64 5.4.4 Tsunami/currentinteractions............. 67 5.5 Recommendations........................ 68 6. Tsunami Impact Forces (Utku Kˆano˘glu and Costas Synolakis) 71 6.1 CurrentsandWaveHeights................... 71 6.2 TheoreticalFramework..................... 71 6.3 ImpactMetrics.......................... 73 6.4 Recommendations........................ 74 7. PoorlyUnderstoodHazards................... 77 7.1 Debris and Projectiles (Utku Kˆano˘glu and Costas Syno- lakis) ............................... 77 7.2 Erosion and Sedimentation (Robert Weiss) ......... 77 7.2.1 Float load and scour erosion . 78 7.2.2 Grain entrainment on sloping beaches and sedimen- tation.......................... 78 7.2.3 Boundary layer development and density increase by grainentrainment................... 81 7.3 Recommendations........................ 82 8. Template THA (Frank Gonz´alezandEricGeist)...... 85 8.1 JapaneseApproach........................ 85 8.1.1 Basicmethodology................... 85 8.1.2 AnalysisinthecontextofU.S.THA......... 86 8.2 InitialScreeningStudy...................... 88 8.3 Probable Maximum Tsunami Study . 90 8.3.1 Definition........................ 91 8.3.2 PMTdevelopment................... 92 8.3.3 PMTanalyses..................... 99 8.4 Real-timeTHA.......................... 100 8.4.1 ImportanceofRTHA................. 100 8.4.2 National infrastructure for RTHA . 101 8.4.3 Tsunami preparedness and response . 103 8.4.4 RTHAenhancement.................. 103 8.5 Probabilistic THA . 105 8.6 Recommendations........................ 105 9. SummaryandRecommendations................ 107 10. Acknowledgments......................... 107 11. References............................. 109 Appendices................................ 125 List of Figures 1-1LocationofU.S.nuclearreactorsites.................. 3 1-2 A tsunami generated on 12 July 1993 by a magnitude 7.8 earthquake off Aonae, Okushiri Island, Japan, completely denuded the exposed Aonae peninsula of built structures and caused severe damage to the port facilities. 5 3-1 Satellite photos taken of northern Sumatra before (left) and after (right) the 2004 South Asia tsunami. 16 3-2 Laterally continuous 1000-yr-old tsunami deposit exposed in a trench, Puget Sound, Washington. 19 Contents v 3-3 Marsh grasses (dark mounds) growing through a tsunami sand sheet in a coastal marsh in Puget Sound, Washington. 19 3-4 Boulder moved by the 1771 Meiwa tsunami in Okinawa, Japan, sur- rounded by coral rubble also moved by the tsunami. 20 4.1-1 Characteristic coseismic vertical displacement profiles (initial tsu- nami wave profiles) for three types of subduction zone earthquakes. 27 4.1-2 Four different forms of the earthquake size distribution tail . 28 4.1-3 Comparison of shear modulus estimates as a function of depth in subductionzones............................. 31 4.2-1 Classification of submarine mass movements adapted from sub-aerial classification proposed by the ISSMGE Technical Committee on Land- slides(TC-11)............................... 32 4.2-2 Approach used for estimating the generation of tsunami for the Palos Verdesdebrisavalanche......................... 33 4.2-3 Bi-linear model of Locat (1997) with the boundary conditions used inthe1DnumericalmodelBING.................... 35 4.2-4 (a) Geometrical description of mobility (hi: initial height, h: flow thickness). (b) Relationship between the run out ratio (height of the slide/travel distance) as a function of the initial volume (Locat and Lee, 2002). 38 5-1 Schematic representation of three stages of tsunami evolution. 45 5-2 Model of the 10 June 1996 Andreanov tsunami source, in which the typical ocean bottom deformation pattern is simulated by the elastic model................................... 47 5-3 Schematic locations of unit sources for the forecast tsunami propa- gationdatabaseinthePacific....................... 48 5-4 Locations of unit sources for the forecast tsunami propagation database intheAtlanticOcean........................... 48 5-5Exampleoftsunamigenerationbyalandslide............. 49 5-6Exampleoftsunamigenerationbyalandslide............. 50 5-7 Maximum computed tsunami amplitudes in the open ocean for the 1996 Andreanov Island tsunami (wave heights in meters). 53 5-8 Comparison of the 1996 Andreanov Island tsunami propagation model (blue line) with deep-ocean bottom pressure recorder (BPR) data (magentaline).............................. 54 5-9 Comparison of the 1993 Hokkaido-Nansei-Oki, Japan, tsunami in- undation model (crosses) with field observations (circles) and stereo photodata(triangles).......................... 56 5-10 Comparison of computed runup heights by computations using dif- ferent grid