landslide tsunami hazard along the upper us east coast effects of slide deformation bottom friction and frequency dispersion numerical simulations of submarine mass failures smfs are performed along the upper us east coast to assess the effect of slide deformation on predicted tsunami hazard tsunami generation is simulated using the three dimensional non hydrostatic model nhwave for rigid slumps the geometry and law of motion are specified as bottom boundary conditions deforming slide motion is modeled using a depth integrated bottom layer of dense newtonian fluid fully coupled to the overlying fluid motion once the smfs are no longer tsunamigenic tsunami propagation simulations are performed using the boussinesq wave model funwave tvd using nested grids of increasingly fine resolution towards shore and employing a one way coupling methodology probable maximum tsunamis are simulated for currituck smf proxies sited in four areas of the shelf break slope that have enough sediment accumulation to cause large failures deforming slides have a slightly larger initial acceleration but still generate a smaller tsunami than rigid slumps due to their spreading and thinning out during motion which gradually makes them less tsunamigenic comparing the maximum envelope of surface elevations along a 5 m isobath consistent with earlier work the bathymetry of the wide shelf is found to strongly control the spatial distribution of tsunami inundation overall tsunamis caused by rigid slumps are worst case scenarios providing up to 50 more inundation than for deforming slides having a moderate level of viscosity set in the upper range of debris flows tsunamis from both types of smfs are able to cause water withdrawal to the 5 m isobath or deeper bottom friction effects are assessed by performing some of the simulations using two different manning coefficients one 50 larger than the other with increased bottom friction the largest tsunami inundations at the coast are reduced by up to 15 selected simulations are rerun by turning off dispersion in the model which leads to moderate changes in maximum surface elevations nearshore 10 to 5 changes but to more significant effects in the far field 40 to 80 changes onshore dispersion causes the appearance of short period undular bores that eventually break nearshore without significantly affecting inundation at the coast however these bores increase wave induced maximum flow velocity and impulse forces the latter by up to 40 which may affect the design of coastal structures

zoisite and clinozoisite segregations in metabasites tauern window austria as evidence for high pressure fluid rock interaction high pressure zoisite and clinozoisite bearing segregations are common in garnet and albite bearing amphibolites of the palaeozoic part of the lower schieferhulle south central tauern window austria the zoisite segregations primary assemblage zo qtz cal formed during an early to pre hercynian high pressure event p 0 6 gpa t 500 550 c by hydrofracturing as a result of protolith dehydration zoisite is growth zoned from fe3 poor cores al 2 fe 9 mol to fe3 rich rims 17 mol and has high sr pb and ga contents and lree enriched ree patterns controlling the trace element budget of the segregations hercynian deformation at c 0 7 gpa 600 c kinked and cracked primary zoisite and enhanced breakdown into secondary zoisite 13 mol al 2 fe clinozoisite 40 55 mol al 2 fe albite an 20 calcite and white mica during an eoalpine high pressure event at 0 9 1 2 gpa 400 500 c the clinozoisite segregations primary assemblage czo qtz omp ttn chl cal are mm to cm wide vein like bodies cross cutting fabric elements of the host garnet amphibolite they formed during the eoalpine high pressure event at 0 9 1 2 gpa 400 500 c during alpine exhumation omphacite was pseudomorphed by amphibole albite quartz and clinozoisite oxygen isotope data suggest equilibrium between host metabasite and zoisite segregations and indicate an internal fluid source and fluid buvering by the protolith mobility of p nb and lree changed the protolith s trace element composition in the vicinity of the zoisite segregations mobilization of lree is evidenced by decreasing modal amounts of lree rich epidote and decreasing lree contents in lree rich epidote towards the segregations chang ing the ree patterns of the host metabasite from lree enriched to lree depleted tectonic discrimi nation diagrams based on the trace element content of metabasites should be applied with extreme caution

tsunami observations in rivers from a perspective of tsunami interaction with tide and riverine flow the observations of the 2011 tohoku tsunami and the 2010 chilean tsunami in several rivers in japan and in the columbia river in the usa are analyzed for patterns of tsunami behavior in river environments tsunamis in rivers exhibit actions very different from those observed on an open coast but very similar among different rivers though the action scale in different rivers varies greatly we describe two tsunami effects in rivers as observed in field data first the river tide modulates the tsunami wave in a very specific way common to all rivers second a strong near field tsunami can cause significant prolonged water accumulation in lower river reaches both effects are inherent in tidal river environments and have been reproduced numerically in a simplified 1 d river using a non linear shallow water model with bottom friction the numerical experiments highlight the indispensable role of a tsunami s interaction with tide and riverine flow

far field tsunami simulations of the 1755 lisbon earthquake implications for tsunami hazard to the u s east coast and the caribbean article i nfo the great lisbon earthquake of november 1st 1755 with an estimated moment magnitude of 8 5 9 0 was the most destructive earthquake in european history the associated tsunami run up was reported to have reached 5 15 m along the portuguese and moroccan coasts and the run up was significant at the azores and madeira island run up reports from a trans oceanic tsunami were documented in the caribbean brazil and newfoundland canada no reports were documented along the u s east coast many attempts have been made to characterize the 1755 lisbon earthquake source using geophysical surveys and modeling the near field earthquake intensity and tsunami effects studying far field effects as presented in this paper is advantageous in establishing constraints on source location and strike orientation because trans oceanic tsunamis are less influenced by near source bathymetry and are unaffected by triggered submarine landslides at the source source location fault orientation and bathymetry are the main elements governing transatlantic tsunami propagation to sites along the u s east coast much more than distance from the source and continental shelf width results of our far and near field tsunami simulations based on relative amplitude comparison limit the earthquake source area to a region located south of the gorringe bank in the center of the horseshoe plain this is in contrast with previously suggested sources such as marques de pombal fault and gulf of cadiz fault which are farther east of the horseshoe plain the earthquake was likely to be a thrust event on a fault striking 345 and dipping to the ene as opposed to the suggested earthquake source of the gorringe bank fault which trends ne sw gorringe bank the madeira tore rise mtr and the azores appear to have acted as topographic scatterers for tsunami energy shielding most of the u s east coast from the 1755 lisbon tsunami additional simulations to assess tsunami hazard to the u s east coast from possible future earthquakes along the azores iberia plate boundary indicate that sources west of the mtr and in the gulf of cadiz may affect the southeastern coast of the u s the azores iberia plate boundary west of the mtr is characterized by strike slip faults not thrusts but the gulf of cadiz may have thrust faults southern florida seems to be at risk from sources located east of mtr and south of the gorringe bank but it is mostly shielded by the bahamas higher resolution near shore bathymetry along the u s east coast and the caribbean as well as a detailed study of potential tsunami sources in the central west part of the horseshoe plain are necessary to verify our simulation results

hydrodynamic modeling of tsunamis from the currituck landslide article i nfo article history accepted 24 september 2008 tsunami generation fromthe currituck landslide offshore northcarolina and propagation of waves towardthe u s coastline are modeled based on recent geotechnical analysis of slide movement a long and intermediate wave modeling package coulwave based on the non linear boussinesq equations are used to simulate the tsunami this model includes procedures to incorporate bottom friction wave breaking and overland flow during runup potential tsunamis generated from the currituck landslide are analyzed using four approaches 1 tsunami wave history is calculated from several different scenarios indicated by geotechnical stability and mobility analyses 2 a sensitivity analysis is conducted to determine the effects of both landslide failure duration during generation and bottom friction along the continental shelf during propagation 3 wave history is calculated over a regional area to determine the propagation of energy oblique to the slide axis and 4 a high resolution 1d model isdeveloped to accuratelymodel wavebreakingand the combined influence of nonlinearity and dispersion during nearshore propagation and runup the primary source parameter that affects tsunami severity for this case study is landslide volume with failure duration having a secondary influence bottom friction during propagation across the continental shelf has a strong influence on the attenuation of the tsunami during propagation the high resolution 1d model also indicates that the tsunami undergoes nonlinear fission prior to wave breaking generating independent short period waves wave breaking occurs approximately 40 50 km offshore where a tsunami bore is formed that persists during runup these analyses illustrate the complex nature of landslide tsunamis necessitating the use of detailed landslide stability mobility models and higher order hydrodynamic models to determine their hazard published by elsevier b v

far field tsunami impact in the north atlantic basin from large scale flank collapses of the cumbre vieja volcano la palma in their pioneering work ward and day suggested that a large scale flank collapse of the cumbre vieja volcano cvv on la palma canary islands could trigger a mega tsunami throughout the north atlantic ocean basin causing major coastal impact in the far field while more recent studies indicate that near field waves from such a collapse would be more moderate than originally predicted by ward and day lovholt et al j geophy res 113 c09026 2008 abadie et al j geophy res 117 c05030 2012 these would still be formidable and devastate the canary island while causing major impact in the far field at many locations along the western european african and the us east coasts abadie et al j geophy res 117 c05030 2012 simulated tsunami generation and near field tsunami impact from a few cvv subaerial slide scenarios with volumes ranging from 20 to 450 km 3 the latter representing the most extreme scenario proposed by ward and day they modeled tsunami generation i e the tsunami source using thetis a 3d navier stokes ns multi fluid vof model in which slide material was considered as a nearly inviscid heavy fluid near field tsunami impact was then simulated for each source using funwave tvd a dispersive and fully nonlinear long wave boussinesq model shi et al ocean modell 43 44 36 51 2012 kirby et al ocean modeling 62 39 55 2013 here using funwave tvd for a series of nested grids of increasingly fine resolution we model and analyze far field tsunami impact from two of abadie et al s extreme cvv flank collapse scenarios i that deemed the most credible worst case scenario based on a slope stability analysis with a 80 km 3 volume and ii the most extreme scenario similar to ward and day s with a 450 km 3 volume simulations are performed using a one way coupling scheme in between two given levels of nested grids based on the simulation results the overall tsunami impact is first assessed in terms of maximum surface elevation computed along the western european and african and us east coasts usec strong wave elevation decay is predicted over the wide usec shelf which is shown to be essentially due to bottom friction effects we then show more detailed results for the usec which is the object of high resolution tsunami inundation mapping under the auspices of the us national tsunami hazard mitigation program in this context we compare the maximum surface elevation predicted along the coastline for each cvv scenario and show that besides the initial directionality of the sources coastal impact is mostly controlled by focusing defocusing effects resulting from the shelf bathymetric features a simplified ray tracing analysis confirms this controlling effect of the wide usec shelf for incident long waves finally we perform high resolution 10 m inundation mapping for the most extreme cvv scenario and show results at one of the most vulnerable and exposed communities in the mid atlantic us states in and around ocean city maryland such maps are being generated for all exposed areas of the usec to be used in tsunami hazard assessment and mitigation work

trace element behavior during serpentinization de serpentinization of an eclogitized oceanic lithosphere a la icpms study of the lanzo ultramafic massif western alps serpentinites are one of the major components of the oceanic lithosphere and are stable in the slab and the mantle wedge up to 100 150 km depth in subduction zones during oceanic mantle hydration and alteration they trap trace and fluid mobile fme b li as sb rb ba cs sr u and pb elements that participate to elemental transfer occurring between the dehydrating slab and the mantle wedge in subduction context the lanzo massif is an eclogitized oceanic lithosphere that preserved its oceanic structure and recorded different steps of serpentinization de serpentinization from oceanic lizardite to prograde antigorite in subduction context up to its dehydration and secondary olivine crystallization and finally retrograde antigorite during massif exhumation it constitutes a suitable place to study trace element behavior during serpentinization de serpentinization processes and associated chemical transfers between the different envelopes of the oceanic lithosphere and the mantle wedge geochemical analyses of serpentine and associated minerals show that the serpentinization de serpentinization of the lanzo massif took place in a relatively closed system without significant trace element transfer between the different parts of the oceanic lithosphere in the deeper part of the lithosphere from the slightly serpentinized mantle peridotites ssp 90 serpentinization in that zone the alpine deformation enhances the mobility of trace elements and permits their redistribution and the homogenization of antigorite composition at massif scale locally in the ssp and ms the crystallization of metamorphic veins of 1 2 m corresponds to channelized fluid flows that allowed fluid transfers and thereby trace elements to longer distance the successive crystallizations of antigorite and then olivine are accompanied by a diminution of some fme b li as sb ba rb and eu contents attesting that these elements are removed from slab to mantle wedge during subduction

decoupling of fluid and trace element release in subducting slab comment on redistribution of trace elements during prograde metamorphism from lawsonite blueschist to eclogite facies implications for deep subduction zone processes by c spandler et al contrib mineral petrol 146 205 222 2003

effect of tides and source location on nearshore tsunami induced currents here we present the results of a numerical modeling study that investigates how event maximum tsunami induced currents vary due to the dynamic effects of tides and wave directivity first analyses of tide tsunami interaction are presented in three harbors by coupling the tsunami with the tide and allowing the initial tsunami wave to arrive at various tidal phases we find that tsunami tide interaction can change the event maximum current speed experienced in a harbor by up to 25 for the events and harbors studied and we note that this effect is highly site specific second to evaluate the effect of wave directionality on event maximum currents earthquakes sources were placed throughout the pacific with magnitudes tuned to create the same maximum near coast amplitude at the harbor of study our analysis also shows that for the harbor and sources examined the effect of offshore directionality and tsunami frequency content has a weak effect on the event maximum currents experienced in the harbor the more important dependency of event maximum currents is the near harbor amplitude of the wave indicating that event maximum currents in a harbor from a tsunami generated by a large far field earthquake may be reasonably well predicted with only information about the predicted local maximum tsunami amplitude this study was motivated by the hope of constructing a basis for understanding the dynamic effects of tides and wave directivity on current based tsunami hazards in a coastal zone the consideration of these aspects is crucial and yet challenging in the modeling of tsunami currents this article is protected by copyright all rights reserved

the 11 march 2011 east japan earthquake and tsunami tsunami effects on coastal infrastructure and buildings the 11 march 2011 east japan earthquake and tsunami caused unprecedented damage to well engineered buildings and coastal structures this report presents some notable field observations of structural damage based on our surveys conducted along the sanriku coast in april and june 2011 engineered reinforced concrete buildings failed by rotation due to the high velocity and deep tsunami inundation entrapped air in the buildings and soil liquefaction by ground shaking could have contributed to the failure the spatial distribution pattern of destroyed and survived buildings indicates that the strength of tsunami was affected significantly by the locations of well engineered sturdy buildings weaker buildings in the shadow zone tended to survive while jet and wake formations behind the sturdy buildings enhanced the tsunami forces we also found that buildings with breakaway walls or breakaway windows doors remained standing even if the surrounding buildings were washed away or destroyed several failure patterns of coastal structures seawalls were observed flow induced suction pressure near the seawall crown could have caused the failure of concrete panels that covered the infill remarkable destruction of upright solid concrete type seawalls was closely related with the tsunami induced scour and soil instability the rapid decrease in inundation depth during the return flow phase caused soil fluidization down to a substantial depth this mechanism explains severely undermined roads and foundations observed in the area of low flow velocities

accuracy assessment of global barotropic ocean tide models the accuracy of state of the art global barotropic tide models is assessed using bottom pressure data coastal tide gauges satellite altimetry various geodetic data on antarctic ice shelves and independent tracked satellite orbit perturbations tide models under review include empirical purely hydrodynamic forward and assimilative dynamical i e constrained by observations ten dominant tidal constituents in the diurnal semidiurnal and quarter diurnal bands are considered since the last major model comparison project in 1997 models have improved markedly especially in shallow water regions and also in the deep ocean the root sum square differences between tide observations and the best models for eight major constituents are approximately 0 9 5 0 and 6 5 cm for pelagic shelf and coastal conditions respectively large intermodel discrepancies occur in high latitudes but testing in those regions is impeded by the paucity of high quality in situ tide records long wavelength components of models tested by analyzing satellite laser ranging measurements suggest that several models are comparably accurate for use in precise orbit determination but analyses of grace intersatellite ranging data show that all models are still imperfect on basin and subbasin scales especially near antarctica for the m2 constituent errors in purely hydrodynamic models are now almost comparable to the 1980 era schwiderski empirical solution indicating marked advancement in dynamical modeling assessing model accuracy using tidal currents remains problematic owing to uncertainties in in situ current meter estimates and the inability to isolate the barotropic mode velocity tests against both acoustic tomography and current meters do confirm that assimilative models perform better than purely hydrodynamic models

tsunami hazard assessment in the hudson river estuary based on dynamic tsunami tide simulations this work is part of a tsunami inundation mapping activity carried out along the us east coast since 2010 under the auspice of the national tsunami hazard mitigation program nthmp the us east coast features two main estuaries with significant tidal forcing which are bordered by numerous critical facilities power plants major harbors as well as densely built low level areas chesapeake bay and the hudson river estuary hre hre is the object of this work with specific focus on assessing tsunami hazard in manhattan the hudson and east river areas in the nthmp work inundation maps are computed as envelopes of maximum surface elevation along the coast and inland by simulating the impact of selected probable maximum tsunamis pmt in the atlantic ocean margin and basin at present such simulations assume a static reference level near shore equal to the local mean high water mhw level here instead we simulate maximum inundation in the hre resulting from dynamic interactions between the incident pmts and a tide which is calibrated to achieve mhw at its maximum level to identify conditions leading to maximum tsunami inundation each pmt is simulated for four different phases of the tide and results are compared to those obtained for a static reference level we first separately simulate the tide and the three pmts that were found to be most significant for the hre these are caused by 1 a flank collapse of the cumbre vieja volcano cvv in the canary islands with a 80 km3 volume representing the most likely extreme scenario 2 an m9 coseismic source in the puerto rico trench prt and 3 a large submarine mass failure smf in the hudson river canyon of parameters similar to the 165 km3 historical currituck slide which is used as a local proxy for the maximum possible smf simulations are performed with the nonlinear and dispersive long wave model funwave tvd in a series of nested grids of increasing resolution towards the coast by one way coupling four levels of nested grids are used from a 1 arc min spherical coordinate grid in the deep ocean down to a 39 m cartesian grid in the hre bottom friction coefficients in the finer grids are calibrated for the tide to achieve the local spatially averaged mhw level at high tide in the hre combined tsunami tide simulations are then performed for four phases of the tide corresponding to each tsunami arriving at sandy hook nj 1 5 h ahead concurrent with 1 5 h after and 3 h after the local high tide these simulations are forced along the offshore boundary of the third level grid by linearly superposing time series of surface elevation and horizontal currents of the calibrated tide and each tsunami wave train this is done in deep enough water for a linear superposition to be accurate combined tsunami tide simulations are then performed with funwave tvd in this and the finest nested grids results show that for the 3 pmts depending on the tide phase the dynamic simulations lead to no or to a slightly increased inundation in the hre by up to 0 15 m depending on location and to larger currents than for the simulations over a static level the crt smf proxy tsunami is the pmt leading to maximum inundation in the hre for all tide phases nonlinear interactions between tide and tsunami currents modify the elevation current and celerity of tsunami wave trains mostly in the shallower water areas of the hre where bottom friction dominates as compared to a linear superposition of wave elevations and currents we note that while dynamic simulations predict a slight increase in inundation this increase may be on the same order as or even less than sources of uncertainty in the modeling of tsunami sources such as their initial water elevation and in bottom friction and bathymetry used in tsunami grids nevertheless results in this paper provide insight into the magnitude and spatial variability of tsunami propagation and impact in the complex inland waterways surrounding new york city and of their modification by dynamic tidal effects we conclude that changes in inundation resulting from the inclusion of a dynamic tide in the specific case of the hre although of scientific interest are not significant for tsunami hazard assessment and that the standard approach of specifying a static reference level equal to mhw is conservative however in other estuaries with similarly complex bathymetry topography and stronger tidal currents a simplified static approach might not be appropriate

crust mantle coupling mechanism in cameroon west africa revealed by 3d s wave velocity and azimuthal anisotropy abstract to understand the depth variation of deformation beneath cameroon west africa we developed a new 3d model of s wave isotropic velocity and azimuthal anisotropy from joint analysis of ambient seismic noise and earthquake surface wave dispersion we found that the cameroon volcanic line cvl is well delineated by slow phase velocities in contrast with the neighboring congo craton in agreement with previous studies apart from the congo craton and the oubanguides belt the uppermost mantle revealed a relatively slow velocity indicating a thinned or thermally altered lithosphere the direction of fast axis in the upper crust is mostly ne sw but trending approximately n s around mt oku and the southern cvl the observed crustal azimuthal anisotropy is attributed to alignment of cracks and crustal deformation related to magmatic activities a widespread zone of weak to zero azimuthal anisotropy in the mid lower crust shows evidence for vertical mantle flow or isotropic mid lower crust in the uppermost mantle the fast axis direction changed from ne sw to nw se around mt oku and northern cameroon this suggests a layered mechanism of deformation and revealed that the mantle lithosphere has been deformed ne sw fast azimuths are observed beneath the congo craton and are consistent with the absolute motion of the african plate suggesting a mantle origin for the observed azimuthal anisotropy our tomographically derived fast directions are consistent with the local sks splitting results in some locations and depths enabling us to constrain the origin of the observed splitting the different feature of azimuthal anisotropy in the upper crust and the uppermost mantle implies decoupling between deformation of crust and mantle in cameroon

tide tsunami interaction in columbia river as implied by historical data and numerical simulations the east japan tsunami of 11 march 2011 propagated more than 100 km upstream in the columbia river visual analysis of its records along the river suggests that the tsunami propagation was strongly affected by tidal conditions a numerical model of the lower columbia river populated with tides and a downstream current was developed simulations of the east japan tsunami propagating up the tidal river reproduced the observed features of tsunami waveform transformation which did not emerge in simulations of the same wave propagating in a quiescent state river this allows us to clearly attribute those features to nonlinear interaction with the tidal river environment the simulation also points to possible amplification of a tsunami wave crest propagating right after the high tide previously deduced from the recordings of the 1964 alaska tsunami in the river

numerical simulation of the 2011 tohoku tsunami based on a new transient fem co seismic source comparison to far and near field observations in this work we simulate the 2011 m9 tohoku oki tsunami using new coseismic tsunami sources based on inverting onshore and offshore geodetic data using 3d finite element models fem such fems simulate elastic dislocations along the plate boundary interface separating the stiff subducting pacific plate from the relatively weak forearc and volcanic arc of the overriding eurasian plate due in part to the simulated weak forearc materials such sources produce significant shallow slip several tens of meters along the updip portion of the rupture near the trench to assess the accuracy of the new approach we compare observations and numerical simulations of the tsunami s far and near field coastal impact for i one of the standard seismic inversion sources ucsb shao et al 2011 and ii the new fem sources specifically results of numerical simulations for both sources performed using the fully nonlinear and dispersive boussinesq wave model funwave tvd are compared to dart buoy gps tide gauge and inundation runup measurements we use a series of nested model grids with varying resolution down to 250 m nearshore and size and assess effects on model results of the latter and of model physics such as when including dispersion or not we also assess the effects of triggering the tsunami sources in the propagation model i either at once as a hot start or with the spatiotemporal sequence derived from seismic inversion and ii as a specified surface elevation or as a more realistic time and space varying bottom boundary condition in the latter case we compute the initial tsunami generation up to 300 s using the non hydrostatic model nhwave although additional refinements are expected in the near future results based on the current fem sources better explain long wave near field observations at dart and gps buoys near japan and measured tsunami inundation while they simulate observations at distant dart buoys as well or better than the ucsb source none of the sources however are able to explain the largest runup and inundation measured between 39 5 and 40 25 n which could be due to insufficient model resolution in this region sanriku ria of complex bathymetry topography and or to additional tsunami generation mechanisms not represented in the coseismic sources e g splay faults submarine mass failure this will be the object of future work

introduction to global tsunami science past and future volume ii twenty two papers on the study of tsunamis are included in volume ii of the pageoph topical issue global tsunami science past and future volume i of this topical issue was published as pageoph vol 173 no 12 2016 eds e l geist h m fritz a b rabinovich and y tanioka three papers in volume ii focus on details of the 2011 and 2016 tsunami generating earthquakes offshore of tohoku japan the next six papers describe important case studies and observations of recent and historical events four papers related to tsunami hazard assessment are followed by three papers on tsunami hydrodynamics and numerical modelling three papers discuss problems of tsunami warning and real time forecasting the final set of three papers importantly investigates tsunamis generated by non seismic sources volcanic explosions landslides and meteorological disturbances collectively this volume highlights contemporary trends in global tsunami research both fundamental and applied toward hazard assessment and mitigation

numerical modeling of tsunami waves generated by the flank collapse of the cumbre vieja volcano la palma canary islands tsunami source and near field effects 1 in this work we study waves generated by the potential collapse of the west flank of the cumbre vieja volcano cvv la palma canary island spain through numerical simulations performed in two stages i the initial slide motion and resulting free surface elevation are first calculated using a 3d navier stokes model ii generated waves are then input into a 2d horizontal boussinesq model to further simulate propagation to the nearby islands unlike in earlier work on cvv besides a similar extreme slide volume scenario of 450 km3 in our simulations i we consider several slide scenarios featuring different volumes i e 20 40 80 km3 which partly result from a geotechnical slope stability analysis ii we use a more accurate bathymetry and iii an incompressible version of a multiple fluid material navier stokes model we find wave trains for each scenario share common features in terms of wave directivity frequency and time evolution but maximum elevations near cvv significantly differ ranging from 600 to 1200 m for increasing slide volume additionally our computations show that significant energy transfer from slide to waves only lasts for a short duration order 200 s which justifies concentrating our best modeling efforts on the early slide motion phase the anticipated consequences of such wave trains on la palma and other canary islands are assessed in detail in the paper

a probabilistic approach for determining submarine landslide tsunami hazard along the upper east coast of the united states abstract tsunami hazard assessment is critical for coastal communities emergency services and industry to develop regional risk and response management plans for catastrophic tsunami events such as the recent 1998 papua new guinea png and 2004 indian ocean tsunamis along the northeastern united states coastline tsunami hazard assessment is in its infancy mostly due to the lack of historical tsunami record and the uncertainty regarding the return periods of potential large scale events the latter includes large transoceanic tsunamis such as could be caused by a collapse of the cumbre vieja volcano in the canary islands or a large co seismic tsunami initiated in the puerto rican trench as well as large local tsunamis such as could be caused by a submarine mass failure smf occurring on the nearby continental slope in this region considerable geologic and some historical e g the 1929 grand bank landslide tsunami evidence suggests that the largest tsunami hazard may arise from tsunamigenic smfs triggered by moderate seismic activity the coastal impact of smf or landslide tsunamis indeed can potentially be narrowly focused and affect specific communities this research presents the development validation and results of a probabilistic geomechanical and coastal tsunami impact analysis of tsunami hazard on the upper northeast coast of the united states results are presented in terms of nearshore breaking wave height and runup caused by seismically induced tsunamigenic smf with a given return period a monte carlo approach is employed in which distributions of relevant parameters seismicity sediment properties type and location volume and dimensions of slide water depth etc are used to perform large numbers of stochastic stability analyses of submerged slopes along actual shelf transects based on standard pseudo static limit equilibrium methods the distribution of predicted slope failures along the upper u s east coast is found to match published data quite well for slopes that are deemed unstable for a specified ground acceleration with given return period the tsunami source characteristic height is found using empirical equations based on earlier numerical simulation work and corresponding breaking height and runup are estimated on the nearest coastline for a 0 2 annual probability ground acceleration for instance simulations yield a return period of tsunamigenic smfs of 3350 yr i e a 0 03 annual probability of occurrence the resulting estimate of the overall coastal hazard from 100 and 500 yr smf tsunami events is found to be quite low at most locations as compared to the typical 100 yr hurricane storm surge in the region 4 5 m specifically for the 100 yr event smf tsunami hazard is quite low with no coastal region exceeding a 1 m runup for the 500 yr event however two regions of relatively elevated hazard are found 1 near long island ny with a peak runup of 3 m and 2 near the new jersey coast with a peak runup of 4 m it should be stressed that these are only first order estimates and detailed tsunami inundation modeling is required to fully quantify tsunami runup and inundation at these sites this will be the object of more detailed studies in future work