effects of rupture complexity on local tsunami inundation implications for probabilistic tsunami hazard assessment by example we investigated the influence of earthquake source complexity on the extent of inundation caused by the resulting tsunami we simulated 100 scenarios with collocated sources of variable slip on the hikurangi subduction interface in the vicinity of hawke s bay and poverty bay in new zealand and investigated the tsunami effects on the cities of napier and gisborne rupture complexity was found to have a first order effect on flow depth and inundation extent for local tsunami sources the position of individual asperities in the slip distribution on the rupture interface control to some extent how severe inundation will be however predicting inundation extent in detail from investigating the distribution of slip on the rupture interface proves difficult assuming uniform slip on the rupture interface in tsunami models can underestimate the potential impact and extent of inundation for example simulation of an mw 8 7 to mw 8 8 earthquake with uniform slip reproduced the area that could potentially be inundated by equivalent nonuniform slip events of mw 8 4 deaggregation to establish the contribution of different sources with different slip distributions to the probabilistic hazard cannot be performed based on magnitude considerations alone we propose two predictors for inundation severity based on the offshore tsunami wavefield using the linear wave equations in an attempt to keep costly simulations of full inundation to a minimum

source location impact on relative tsunami strength along the u s west coast tsunami propagation simulations are used to identify which tsunami source locations would produce the highest amplitude waves on approach to key population centers along the u s west coast the reasons for preferential influence of certain remote excitation sites are explored by examining model time sequences of tsunami wave patterns emanating from the source distant bathymetric features in the west and central pacific can redirect tsunami energy into narrow paths with anomalously large wave height that have disproportionate impact on small areas of coastline the source region generating the waves can be as little as 100 km along a subduction zone resulting in distinct source target pairs with sharply amplified wave energy at the target tsunami spectral ratios examined for transects near the source after crossing the west pacific and on approach to the coast illustrate how prominent bathymetric features alter wave spectral distributions and relate to both the timing and magnitude of waves approaching shore to contextualize the potential impact of tsunamis from high amplitude source target pairs the source characteristics of major historical earthquakes and tsunamis in 1960 1964 and 2011 are used to generate comparable events originating at the highest amplitude source locations for each coastal target this creates a type of worst case scenario a replicate of each region s historically largest earthquake positioned at the fault segment that would produce the most incoming tsunami energy at each target port an amplification factor provides a measure of how the incoming wave height from the worst case source compares to the historical event

evaluation of the relationship between coral damage and tsunami dynamics case study 2009 samoa tsunami on september 29 2009 an mw 8 1 earthquake at 17 48 utc in tonga trench generated a tsunami that caused heavy damage across samoa american samoa and tonga islands tutuila island which is located 250 km from the earthquake epicenter experienced tsunami flooding and strong currents on the north and east coasts causing 34 fatalities out of 192 total deaths from this tsunami and widespread structural and ecological damage the surrounding coral reefs also suffered heavy damage the damage was formally evaluated based on detailed surveys before and immediately after the tsunami this setting thus provides a unique opportunity to evaluate the relationship between tsunami dynamics and coral damage in this study estimates of the maximum wave amplitudes and coastal inundation of the tsunami are obtained with the most model titov and synolakis j waterway port coast ocean eng pp 171 1998 titov and gonzalez noaa tech memo erl pmel 112 11 1997 which is now the operational tsunami forecast tool used by the national oceanic and atmospheric administration noaa the earthquake source function was constrained using the real time deep ocean tsunami data from three dart deep ocean assessment and reporting for tsunamis systems in the far field and by tide gauge observations in the near field we compare the simulated run up with observations to evaluate the simulation performance we present an overall synthesis of the tide gauge data survey results of the run up inundation measurements and the datasets of coral damage around the island these data are used to assess the overall accuracy of the model run up prediction for tutuila and to evaluate the model accuracy over the coral reef environment during the tsunami event our primary findings are that 1 most simulated run up correlates well with observed run up for this event r 0 8 it tends to underestimated amplitudes over coral reef environment around tutuila for 15 of 31 villages run up is underestimated by more than 10 in only 5 was run up overestimated by more than 10 and 2 the locations where the model underestimates run up also tend to have experienced heavy or very heavy coral damage 8 of the 15 villages whereas well estimated run up locations characteristically experience low or very low damage 7 of 11 villages these findings imply that a numerical model may overestimate the energy loss of the tsunami waves during their interaction with the coral reef we plan future studies to quantify this energy loss and to explore what improvements can be made in simulations of tsunami run up when simulating coastal environments with fringing coral reefs

fault slip and seismic moment of the 1700 cascadia earthquake inferred from japanese tsunami descriptions 1 the 1700 cascadia earthquake attained moment magnitude 9 according to new estimates based on effects of its tsunami in japan computed coseismic seafloor deformation for hypothetical ruptures in cascadia and tsunami modeling in the pacific ocean reports of damage and flooding show that the 1700 cascadia tsunami reached 1 5 m heights at seven shoreline sites in japan three sets of estimated heights express uncertainty about location and depth of reported flooding landward decline in tsunami heights from shorelines and post 1700 land level changes we compare each set with tsunami heights computed from six cascadia sources each source is vertical seafloor displacement calculated with a three dimensional elastic dislocation model for three sources the rupture extends the 1100 km length of the subduction zone and differs in width and shallow dip for the other sources ruptures of ordinary width extend 360 670 km to compute tsunami waveforms we use a linear long wave approximation with a finite difference method and we employ modern bathymetry with nearshore grid spacing as small as 0 4 km the various combinations of japanese tsunami heights and cascadia sources give seismic moment of 1 9 1022 n m equivalent to moment magnitude 8 7 9 2 this range excludes several unquantified uncertainties the most likely earthquake of moment magnitude 9 0 has 19 m of coseismic slip on an offshore full slip zone 1100 km long with linearly decreasing slip on a downdip partial slip zone the shorter rupture models require up to 40 m offshore slip and predict land level changes inconsistent with coastal paleoseismological evidence

parallel implementation of dispersive tsunami wave modeling with a nesting algorithm for the 2011 tohoku tsunami because of improvements in offshore tsunami observation technology dispersion phenomena during tsunami propagation have often been observed in recent tsunamis for example the 2004 indian ocean and 2011 tohoku tsunamis the dispersive propagation of tsunamis can be simulated by use of the boussinesq model but the model demands many computational resources however rapid progress has been made in parallel computing technology in this study we investigated a parallelized approach for dispersive tsunami wave modeling our new parallel software solves the nonlinear boussinesq dispersive equations in spherical coordinates a variable nested algorithm was used to increase spatial resolution in the target region the software can also be used to predict tsunami inundation on land we used the dispersive tsunami model to simulate the 2011 tohoku earthquake on the supercomputer k good agreement was apparent between the dispersive wave model results and the tsunami waveforms observed offshore the finest bathymetric grid interval was 2 9 arcsec approx 5 m along longitude and latitude lines use of this grid simulated tsunami soliton fission near the sendai coast incorporating the three dimensional shape of buildings and structures led to improved modeling of tsunami inundation

tsunami inundation from heterogeneous earthquake slip distributions evaluation of synthetic source models this study investigates whether eight different synthetic finite fault models sffm can simulate stochastic earthquake tsunami with similar statistical properties to real earthquake tsunami events where the latter are represented using heterogeneous slip distributions from 66 finite fault inversions ffi for oceanic subduction interface earthquakes a new method is derived to estimate sffm parameters from ffi and predictive relations between the earthquake moment magnitude and the sffm corner wave numbers are developed to support model applications sffm with more capacity to spatially localize slip are better able to simulate higher slip regions on the ffi and this strongly influences their associated tsunami inundation which is computed in two dimensions over idealized topography the best performing sffm generates tsunami inundation which envelopes the ffi inundation in 81 of cases using 10 synthetic events close to the ideal value of 82 while the other sffm show greater tendencies to underestimate inundation these differences are related to the capacity of each sffm to produce spatially localized slip distributions none of the sffm showed a tendency to overpredict inundation the results highlight that sffm cannot be assumed to reliably quantify uncertainties in the tsunami inundation of real earthquakes and the use of untested sffm could create nonconservative bias in tsunami hazard assessments however the most successful model used here performs quite well although it may still underestimate inundation more often than an optimal model

linear and nonlinear computations of the 1992 nicaragua earthquake tsunami numerical computations of tsunamis are made for the 1992 nicaragua earthquake using different governing equations bottom frictional values and bathymetry data the results are compared with each other as well as with the observations both tide gauge records and runup heights comparison of the observed and computed tsunami waveforms indicates that the use of detailed bathymetry data with a small grid size is more effective than to include nonlinear terms in tsunami computation linear computation overestimates the amplitude for the later phase than the first arrival particularly when the amplitude becomes large the computed amplitudes along the coast from nonlinear computation are much smaller than the observed tsunami runup heights the average ratio or the amplification factor is estimated to be 3 in the present case when the grid size of 1 minute is used the factor however may depend on the grid size for the computation

near field tsunami edge waves and complex earthquake rupture the effect of distributed coseismic slip on progressive near field edge waves is examined for continental shelf tsunamis detailed observations of edge waves are difficult to separate from the other tsunami phases that are observed on tide gauge records in this study analytic methods are used to compute tsunami edge waves distributed over a finite number of modes and for uniformly sloping bathymetry coseismic displacements from static elastic theory are introduced as initial conditions in calculating the evolution of progressive edge waves both simple crack representations constant stress drop and stochastic slip models heterogeneous stress drop are tested on a fault with geometry similar to that of the m w 8 8 2010 chile earthquake crack like ruptures that are beneath or that span the shoreline result in similar longshore patterns of maximum edge wave amplitude ruptures located farther offshore result in reduced edge wave excitation consistent with previous studies introduction of stress drop heterogeneity by way of stochastic slip models results in significantly more variability in longshore edge wave patterns compared to crack like ruptures for the same offshore source position in some cases regions of high slip that are spatially distinct will yield sub events in terms of tsunami generation constructive interference of both non trapped and trapped waves can yield significantly larger tsunamis than those that produced by simple earthquake characterizations

kuril islands tsunami of november 2006 1 impact at crescent city by distant scattering 1 a numerical model for the global tsunami computation constructed by kowalik et al 2005 2007a is applied to the tsunami of november 15 2006 in the northern pacific with spatial resolution of one minute numerical results are compared to sea level data collected by pacific dart buoys the tide gauge at crescent city cc recorded an initial tsunami wave of about 20 cm amplitude and a second larger energy packet arriving 2 hours later the first energy input into the cc harbor was the primary direct wave traveling over the deep waters of the north pacific interactions with submarine ridges and numerous seamounts located in the tsunami path were a larger source of tsunami energy than the direct wave travel time for these amplified energy fluxes is longer than for the direct wave prime sources for the larger fluxes at cc are interactions with koko guyot and hess rise tsunami waves travel next over the mendocino escarpment where the tsunami energy flux is concentrated owing to refraction and directed toward cc local tsunami amplification over the shelf break and shelf are important as well in many locations along the north pacific coast the first arriving signal or forerunner has lower amplitude than the main signal which often is delayed understanding this temporal distribution is important for an application to tsunami warning and prediction as a tsunami hazard mitigation tool we propose that along with the sea level records which are often quite noisy an energy flux for prediction of the delayed tsunami signals be used

development testing and applications of site specific tsunami inundation models for real time forecasting 1 the study describes the development testing and applications of site specific tsunami inundation models forecast models for use in noaa s tsunami forecast and warning system the model development process includes sensitivity studies of tsunami wave characteristics in the nearshore and inundation for a range of model grid setups resolutions and parameters to demonstrate the process four forecast models in hawaii at hilo kahului honolulu and nawiliwili are described the models were validated with fourteen historical tsunamis and compared with numerical results from reference inundation models of higher resolution the accuracy of the modeled maximum wave height is greater than 80 when the observation is greater than 0 5 m when the observation is below 0 5 m the error is less than 0 3 m the error of the modeled arrival time of the first peak is within 3 of the travel time the developed forecast models were further applied to hazard assessment from simulated magnitude 7 5 8 2 8 7 and 9 3 tsunamis based on subduction zone earthquakes in the pacific the tsunami hazard assessment study indicates that use of a seismic magnitude alone for a tsunami source assessment is inadequate to achieve such accuracy for tsunami amplitude forecasts the forecast models apply local bathymetric and topographic information and utilize dynamic boundary conditions from the tsunami source function database to provide site and event specific coastal predictions only by combining a deep ocean assessment and reporting of tsunami constrained tsunami magnitude with site specific high resolution models can the forecasts completely cover the evolution of earthquake generated tsunami waves generation deep ocean propagation and coastal inundation wavelet analysis of the tsunami waves suggests the coastal tsunami frequency responses at different sites are dominated by the local bathymetry yet they can be partially related to the locations of the tsunami sources the study also demonstrates the nonlinearity between offshore and nearshore maximum wave amplitudes

far field tsunami hazard in new zealand ports we present the results of a numerical modeling study investigating the effects of far field tsunamis in new zealand ports four sites marsden point tauranga harbor port taranaki and lyttelton harbor were selected based on a combination of factors such as economic importance and the availability of historical and or instrumental data numerical models were created using the commit tsunami modeling tool and the method of splitting tsunami most hydrodynamic model comparison of model results to measured data from recent historical events showed that for particular sites and events the model correlated well with the timing and amplitude of the observed tsunami and in most cases there was generally good agreement between the and modeled tsunami heights and current speeds a sensitivity analysis for tsunami heights and current speeds was conducted using a suite of large m w 9 tsunamigenic earthquake sources situated at regular 15 intervals in azimuth along the pacific rim while another set of scenarios focused on regional tsunami sources in the southwest pacific model results were analyzed for tsunami heights and current speeds as a function of the source region in terms of currents the analysis identified where speeds were greatest and which source was responsible results suggested that tsunamis originating from central america produced the strongest response in new zealand the modeling was also used to determine the timing and duration of potentially dangerous current speeds as well as minimum safe depths for vessel evacuation offshore this study was motivated by the desire to reduce damage and operational losses via improved forecasting of far field tsunamis at new zealand ports it is important that forecasts are accurate since tsunami damage to ships and facilities is expensive and can be mitigated given timely warnings and because preventable false alarms are also costly in terms of lost productivity the modeling presented here will underpin efforts to produce port specific guidance and information in the event of future pacific tsunamis

the october 28 2012 mw 7 8 haida gwaii underthrusting earthquake and tsunami slip partitioning along the queen charlotte fault transpressional plate boundary the pacific north american plate boundary is undergoing predominantly right lateral strike slip motion along the queen charlotte and fairweather transform faults the queen charlotte fault qcf hosted the largest historical earthquake in canada the 1949 m s 8 1 strike slip earthquake which ruptured from offshore northern haida gwaii several hundred kilometers northwestward on january 5 2013 an m w 7 5 strike slip faulting event occurred near the northern end of the 1949 rupture zone along central and southern haida gwaii the relative plate motion has 20 oblique convergence across the left stepping plate boundary there had been uncertainty in how the compressional component of plate motion is accommodated the october 28 2012 m w 7 8 haida gwaii earthquake involved slightly 20 oblique thrust faulting on a shallow 18 5 northeast dipping fault plane with strike 320 parallel to the qcf consistent with prior inferences of pacific plate underthrusting beneath haida gwaii the rupture extended to shallow depth offshore of moresby island beneath a 25 30 km wide terrace of sediments that has accumulated in a wedge seaward of the qcf the shallow thrusting caused seafloor uplift that generated substantial localized tsunami run up and a modest far field tsunami that spread across the northern pacific prompting a tsunami warning beach closure and coastal evacuation in hawaii although ultimately tide gauges showed less than 0 8 m of water level increase the mainshock rupture appears to have spread with a 2 3 km s rupture velocity over a length of 150 km with slip averaging 3 3 m concentrated beneath the sedimentary wedge the event was followed by a substantial aftershock sequence in which almost all of the larger events involve distributed intraplate normal faulting extending 50 km oceanward from the qcf the highly oblique slip partitioning in southern haida gwaii is distinctive in that the local plate boundary parallel motion on the qcf may be accommodated either by infrequent large strike slip ruptures or by aseismic creep as seems to be the case for deeper oblique relative plate motion beneath haida gwaii while the sedimentary terrace accumulates plate boundary perpendicular compressional strain that releases in almost pure thrust faulting earthquakes seaward of the qcf

display and assessment of earthquake focal mechanisms by vector representation the isomorphism between symmetric three dimensional second order tensors and six dimensional vectors is exploited to display suites of seismic moment tensors and to asses their similarities and differences both graphically and quantitatively using the southern mid atlantic ridge as an example i show that this method successfully differentiates between different mechanism types and orientations in addition the dispersion within a group of mechanisms is successfully quantified

constraints on the long period moment dip tradeoff for the tohoku earthquake since the work of kanamori and given 1981 it has been recognized that shallow pure dip slip earthquakes excite long period surface waves such that it is difficult to independently constrain the moment m 0 and the dip of the source mechanism with only the product m 0 sin 2 being well constrained because of this it is often assumed that the primary discrepancies between the moments of shallow thrust earthquakes are due to this moment dip tradeoff in this work we quantify how severe this moment dip tradeoff is depending on the depth of the earthquake the station distribution the closeness of the mechanism to pure dip slip and the quality of the data we find that both long period rayleigh and love wave modes have moment dip resolving power even for shallow events especially when stations are close to certain azimuths with respect to mechanism strike and when source depth is well determined we apply these results to usgs w phase inversions of the recent m9 0 tohoku japan earthquake and estimate the likely uncertainties in dip and moment associated with the moment dip tradeoff after discussing some of the important sources of moment and dip error we suggest two methods for potentially improving this uncertainty

traveltime delay and initial phase reversal of distant tsunamis coupled with the self gravitating elastic earth systematic tsunami traveltime delays of up to 15 min relative to the numerically simulated long waves from the 2010 chilean and 2011 tohoku oki earthquakes were widely observed at deep ocean tsunamimeters enigmatic small negative phases appearing before the main peak were commonly found only at the trans oceanic locations the frequency dependence of the measured tsunami phase velocities shows reverse dispersions at long periods i e the tsunami speed becomes slower at periods beyond 1000 s this is consistent with the phase velocities of a tsunami mode coupled with a self gravitating elastic earth suggesting that the effects of compression and dilatation of seawater elastic tsunami loadings on a solid earth and the geopotential variations associated with the motion of mass during tsunami propagation are responsible for the traveltime delays and the initial negative phases simple 1 d tsunami propagation tests confirm that the reverse dispersion creates a small negative phase that precedes the main peak at large distances a new method to simulate tsunami waveforms on real ocean bathymetry that takes into account seawater compressibility the elasticity of the earth and geopotential perturbations has been developed by applying a phase correction to the simulated long waves the simulated waveforms in which phase corrections are applied for the dispersion effects accurately reproduce the observed waveforms including a small initial negative phase that appears at distant locations the traveltime difference between the observed and simulated waveforms has been decreased to less than 5 min and the waveform difference between them remarkably diminishes

local tsunamis and distributed slip at the source variations in the local tsunami wave field are examined in relation to heterogeneous slip distributions that are characteristic of many shallow subduction zone earthquakes assumptions inherent in calculating the coseismic vertical displacement field that defines the initial condition for tsunami propagation are examined by comparing the seafloor displacement from uniform slip to that from an ideal static crack we demonstrate that dip directed slip variations significantly affect the initial cross sectional wave profile because of the hydrodynamic stability of tsunami wave forms these effects directly impact estimates of maximum runup from the local tsunami in most cases an assumption of uniform slip in the dip direction significantly underestimates the maximum amplitude and leading wave steepness of the local tsunami whereas dip directed slip variations affect the initial wave profile strike directed slip variations result in wavefront parallel changes in amplitude that are largely preserved during propagation from the source region toward shore owing to the effects of refraction tests of discretizing slip distributions indicate that small fault surface elements of dimensions similar to the source depth can acceptably approximate the vertical displacement field in comparison to continuous slip distributions crack models for tsunamis generated by shallow subduction zone earthquakes indicate that a rupture intersecting the free surface results in approximately twice the average slip therefore the observation of higher slip associated with tsunami earthquakes relative to typical subduction zone earthquakes of the same magnitude suggests that tsunami earthquakes involve rupture of the seafloor whereas rupture of deeper subduction zone earthquakes may be imbedded and not reach the seafloor

the 25 october 2010 mentawai tsunami earthquake from real time discriminants finite fault rupture and tsunami excitation 1 the moment magnitude 7 8 earthquake that struck offshore the mentawai islands in western indonesia on 25 october 2010 created a locally large tsunami that caused more than 400 human causalities we identify this earthquake as a rare slow source tsunami earthquake based on 1 disproportionately large tsunami waves 2 excessive rupture duration near 125 s 3 predominantly shallow near trench slip determined through finite fault modeling and 4 deficiencies in energy to moment and energy to duration cubed ratios the latter in near real time we detail the real time solutions that identified the slow nature of this event and evaluate how regional reductions in crustal rigidity along the shallow trench as determined by reduced rupture velocity contributed to increased slip causing the 5 9 m local tsunami runup and observed transoceanic wave heights observed 1600 km to the southeast

dispersive modeling of the 2009 samoa tsunami 1 in this study we investigate the dispersive effects in the 2009 samoa tsunami through numerical simulations the wave propagation is first simulated with a weakly nonlinear and dispersive boussinesq model and a non dispersive shallow water equations model comparison of the numerical results between these models indicates that tsunami propagation is significantly affected by the frequency dispersion east of tonga trench neglecting dispersive effects results in larger wave heights and speeds the strong frequency dispersion is primarily attributed to the dramatic variation of water surface elevations generated by the earthquake doublet and enhanced by the uneven bathymetry in tonga trench tsunami propagation is also simulated with most method of splitting tsunamis which is based on the shallow water equations but uses numerical dispersion to mimic physical frequency dispersion at operational resolutions a good agreement is observed between most and the boussinesq model as well as the field measurements in the leading wave in the shorter trailing waves agreement becomes poorer due to the mismatch between numerical and physical dispersions

spectral behavior of gravel dunes abstract spectral behavior of gravel dunes formed under different flow discharges is analyzed with an attempt to verify the 3 spectral law that has been confirmed extensively for sand dunes a schematic spectrum of gravel dunes is proposed based on the spectral analysis as well as results from the literature the results of spectral analysis show a significant deviation from the 3 spectral law for gravel dunes and the magnitude of deviation correlates with flow discharge possible explanations for the deviation from the 3 spectral law being associated with kinetic and geometrical characteristics have been explored to investigate the kinetic characteristics of gravel dunes a wavelet based method that calculates the celerity of dunes based on a pair of elevational time series is quantitatively tested our results suggest that 1 the kinetic explanation based on the relationship between dune celerity and dune length cannot fully explain the spectral behavior of gravel dunes 2 the geometrical explanation based on the self similarity hypothesis is confirmed by the relationship between dune length and dune height and 3 the development of gravel sheets accounts for the differences in kinetic and geometrical characteristics between gravel dunes and sand dunes

rapid forecast of tsunami wave heights from a database of pre computed simulations and application during the 2011 tohoku tsunami in french polynesia 1 we present a method for the rapid estimation of tsunami wave heights either in the deep pacific basin or at specific shore locations it uses a database of 260 pre computed scenarios of generic sources distributed along the pacific trenches and can provide an estimate of wave heights within minutes of the location of the earthquake and the estimation of its moment the method is tested against a set of dart data and of 51 maregraph records in tahiti and the marquesas islands it was used in real time to successfully predict tsunami amplitudes in polynesia during the 2011 tohoku alert

the 2006 july 17 java indonesia tsunami from satellite imagery and numerical modelling a single or complex source summary the mw 7 8 2006 july 17 earthquake off the southern coast of java indonesia has been responsible for a very large tsunami causing more than 700 casualties the tsunami has been observed on at least 200 km of coastline in the region of pangandaran west java with run up heights from 5 to more than 20 m such a large tsunami with respect to the source magnitude has been attributed to the slow character of the seismic rupture defining the event as a so called tsunami earthquake but it has also been suggested that the largest run up heights are actually the result of a second local landslide source here we test whether a single slow earthquake source can explain the tsunami run up using a combination of new detailed data in the region of the largest run ups and comparison with modelled run ups for a range of plausible earthquake source models using high resolution satellite imagery spot 5 and quickbird the coastal impact of the tsunami is refined in the surroundings of the high security permisan prison on nusa kambangan island where 20 m run up had been recorded directly after the event these data confirm the extreme inundation lengths close to the prison and extend the area of maximum impact further along the nusa kambangan island about 20 km of shoreline where inundation lengths reach several hundreds of metres suggesting run up as high as 10 15 m tsunami modelling has been conducted in detail for the high run up permisan area nusa kambangan and the pltu power plant about 25 km eastwards where run up reached only 4 6 m and a video recording of the tsunami arrival is available for the permisan prison a high resolution dem was built from stereoscopic satellite imagery the regular basin of the pltu plant was designed using photographs and direct observations for the earthquake s mechanism both static infinite and finite kinematic ruptures are investigated using two published source models the models account rather well for the sea level variation at pltu showing a better agreement in arrival times with the finite rupture and predict the permisan area to be one of the regions where tsunami waves would have focussed however the earthquake models that match the data at ptlu do not predict that the wave heights at permisan are an overall maximum and do not predict there more than 10 m of the 21 observed hence our results confirm that an additional localized tsunami source off nusa kambangan island such as a submarine landslide may have increased the tsunami impact for the permisan site this reinforces the importance for hazard assessment of further mapping and understanding local potential for submarine sliding as a tsunami source added to usual earthquake sources

historical tsunamis and present tsunami hazard in eastern indonesia and the southern philippines 1 eastern indonesia and the southern philippines comprise a huge and seismically highly active region that has received less than the deserved attention in tsunami research compared with the surrounding areas exposed to the major subduction zones in an effort to redress the balance the tsunami hazard in this region is studied by establishing a tsunami event database which in combination with seismological and tectonic information from the region has allowed us to define and justify a number of credible worst case tsunami scenarios these scenarios have been used in numerical simulations of tsunami generation and propagation to study maximum water level along potentially affected shorelines the scenarios have in turn been combined to provide regional tsunami hazard maps in many cases the simulations indicate that the maximum water level may exceed 10 m locally and even reach above 20 m in the vicinity of the source which is of the same order as what is forecasted along the sumatra and java trenches for comparable return periods for sections of coastlines close to a source a tsunami may strike only a few minutes after it is generated providing little time for warning moreover several of the affected areas are highly populated and are therefore also high risk areas the combination of high maximum water levels short warning times dense populations and relatively short return periods suggests strongly that the tsunami hazard and risk in these regions are alarmingly high