coastal impacts of the march 11th tohoku japan tsunami in the galapagos islands on march 11 2011 at 5 46 23 utc march 10 11 46 23 pm galapagos local time the mw 9 0 great east japan earthquake occurred near the tohoku region off the east coast of japan spawning a pacific wide tsunami approximately 12 000 km away the galapagos islands experienced moderate tsunami impacts including flooding structural damage and strong currents in this paper we present observations and measurements of the tsunami effects in the galapagos focusing on the four largest islands in the archipelago from west to east isabela santiagio santa cruz and san cristobal access to the tsunami affected areas was one of the largest challenges of the field survey aside from approximately ten sandy beaches open to tourists all other shoreline locations are restricted to anyone without a research permit open cooperation with the galapagos national park provided the survey team complete access to the islands coastlines survey locations were guided by numerical simulations of the tsunami performed prior to the field work this numerical guidance accurately predicted the regions of highest impact as well as regions of relatively low impact tide corrected maximum tsunami heights were generally in the range of 3 4 m with the highest runup of 6 m measured in a small pocket beach on isla isabela puerto ayora on santa cruz island the largest harbor in the galapagos experienced significant flooding and damage to structures located at the shoreline a current meter moored inside the harbor recorded relatively weak tsunami currents of less than 0 3 m s 0 6 knot during the event comparisons with detailed numerical simulations suggest that these low current speed observations are most likely the result of data averaging at 20 min intervals and that maximum instantaneous current speeds were considerably larger currents in the canal de itabaca a natural waterway between santa cruz island and a smaller island offshore were strong enough to displace multiple 5 5 ton navigation buoys numerical simulations indicate that currents in the canal de itabaca exceeded 4 m s 8 knots a very large flow speed for a navigational waterway

stable carbon isotope stratigraphy of the paleogene pedogenic series of southern france as a basis for continental marine correlation the upper cretaceous lower paleogene formations in the aix en provence basin are characterized by interfingering lacustrine carbonates and flood plain alluvium the deposits from both environments display numerous horizons of carbonate rich paleosols by using a combined magnetostratigraphy and carbon isotope stratigraphy for the pedogenic carbonate glaebules we constructed a detailed integrated stratigraphy for the entire lower paleogene this method provides a way to correlate marine and terrestrial sequences when c3 plants dominated the environment both long term and short term 13 c variations were identified in the provence series 1 the uniform carbon isotope record established through the end of the maastrichtian followed by the abruptly negative carbon isotope excursion in the lowermost paleocene provides a marker for the precise location of the cretaceous tertiary boundary in this basin 5 m below the calcaire de vitrolles formation 2 a gradual 13 c increase through the middle upper paleocene similar in amplitude to that of the marine realm 3 a short term negative 13 c excursion in the latest paleocene as seen within the calcaire de st marc formation and 4 a slow decrease during the late paleocene to early eocene with a probable hiatus in the sedimentary record the provence mammal site of palette is shown to be stratigraphically younger than the late paleocene negative 13 c excursion

structure and evolution of tidal starting jet vortices at idealized barotropic inlets 1 we present laboratory experiments for tidal starting jet vortices forming at idealized barotropic inlets using dye visualization and particle image velocimetry piv of the surface velocity field vortices are identified in the piv data using the local swirl strength and metrics are calculated for each identified vortex including position equivalent circular diameter maximum vorticity circulation and upwelling potential these quantitative metrics are presented for four different inlet layouts including narrow and wide barrier islands and short and long jetties in each case starting jet eddies initially form attached to the inlet mouth with a rapid increase in vorticity circulation and size as water exiting the inlet flows directly into the starting jet dipole once the vortices reach a critical size they are entrained into the tidal jet and detach from the inlet as they advect away from the inlet their size remains steady while the maximum vorticity and circulation gradually decrease because of the effect of bottom friction and the reduction of input to the vortices from the tidal flow as a result of their advection within the tidal jet secondary vortices shed from the inlet during the quasi steady tidal jet are also entrained into the starting jet vortices decreasing the overall rate at which their vorticity and circulation decay downstream of the inlet the quantitative results indicate that the starting jet eddies grow detach from the inlet mouth and decay at predictable non dimensional rates and times

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

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

porosity of late paleocene ornitholithus eggshells tremp fm south central pyrenees spain palaeoclimatic implications eggshell fragments of ratite type ornitholithus oofamily elongatoolithidae attributed to giant birds are described from upper paleocene deposits in the pyrenean provence region we study the porosity of a rich ornitholithus sample from claret 4 locality tremp fm lleida spain closely related to the global warming event which took place at the paleocene eocene boundary petm in order to infer relations between egg conductance nesting habits and palaeoenviromental conditions an egg mass of around 3 kg is inferred for the large ornitholithus eggs in agreement with the values previously estimated by touraine touraine f 1960 oeufs d oiseaux de tres grande taille dans l eocene inferieur de provence pp 783 789 but lower than those obtained by dughi and sirugue dughi r sirugue f 1962 distribution verticale des oeufs d oiseaux fosiles de l eocene de basse provence bull soc geol fr 7 69 78 o arquatus group 8 7 kg porosity observed in ornitholithus eggshells is extremely reduced in comparison to bird eggs and even much more reduced in relation to theropod dinosaurs pore number is similar to that of bird eggs but most ornitholithus pores are exceedingly small micropores thus pore radius and total pore area is much lower than in recent birds moreover ornitholithus micropores lack connectivity between them thus decreasing functional pore area and permeability the function of micropores could be related to weight spare favorable hatching and or thermal isolation ornitholithus eggshells are the most compact of all bird or theropod eggshells studied so far consequently calculated water vapor conductance values in ornitholithus eggs are in average 8 times lower than that for recent birds the relation between egg conductance and nesting environment shown in recent birds suggests in the case of ornitholithus an open and extremely dry nest environment anomalous compact ornitholithus eggshells could help to keep eggs inner relatively constant temperature and humidity in the extremely warm and dry palaeoenvironment inferred for the pyrenean region at the paleocene eocene thermal maximum

currents drag and sediment transport induced by a tsunami 1 we report observations of water surface elevation currents and suspended sediment concentration ssc from a 10 m deep site on the inner shelf in northern monterey bay during the arrival of the 2010 chile tsunami velocity profiles were measured from 3 5 m above the bed mab to the surface at 2 min intervals and from 0 1 to 0 7 mab at 1 hz ssc was determined from the acoustic backscatter of the near bed profiler the initial tsunami waves were directed cross shore and had a period of approximately 16 min maximum wave height was 1 1 m and maximum current speed was 0 36 m s during the strongest onrush near bed velocities were clearly influenced by friction and a logarithmic boundary layer developed extending more than 0 3 mab we estimated friction velocity and bed shear stress from the logarithmic profiles the logarithmic structure indicates that the flow can be characterized as quasi steady at these times at other phases of the tsunami waves the magnitude of the acceleration term was significant in the near bed momentum equation indicating unsteady flow the maximum tsunami induced bed shear stress 0 4 n m2 exceeded the critical shear stress for the medium grained sand on the seafloor cross shore sediment flux was enhanced by the tsunami oscillations of water surface elevation and currents continued for several days the oscillations were dominated by resonant frequencies the most energetic of which was the fundamental longitudinal frequency of monterey bay the maximum current speed hourly timescale in 18 months of observations occurred four hours after the tsunami arrived

diet and climatic context of giant birds inferred from δ13cc and δ18oc values of late palaeocene and early eocene eggshells from southern france abstract abundant fragments from eggs laid by giant birds occur in the palaeocene thanetian and eocene sparnacian sedimentary deposits of southeastern france in the sparnacian thick eggshell fragments assigned to the oospecies ornitholithus arcuatus correspond to very large bird eggs that were most likely laid by gastornis the thanetian thin eggshell fragments assigned to ornitholithus biroi were presumably laid by a smaller yet unidentified bird in order to investigate ecology and environment of these egg laying birds stable carbon and oxygen isotope compositions of 125 fossil eggshell fragments were analyzed after removing samples affected by diagenetic alteration of the calcitic shells the measured range of 13cc values 11 to 6 v pdb is interpreted as reflecting an herbivorous diet for these birds in a context of limited annual precipitation 500 mm y 1 stable oxygen isotope analysis of living ostrich eggshell calcite along with that of the water extracted from their albumen and yolk provided evidence to calculate isotopic fractionation factors between both calcite and body water calcite body water 1 03041 and between body water and meteoric water bw mw 1 00399 using 18o values of local meteoric waters identified as the source of the birds drinking water combined with the 18o values of fossil eggshells both isotopic fractionations provided calculated 18o values of meteoric waters in the range 9 5 to 2 8 v smow for the thanetian and in the range 8 9 to 1 7 v smow for the sparnacian these large isotopic ranges likely reflect inter annual temperature variations of the complete year suggesting a year round egg laying strategy corresponding mean air temperatures mat were comprised between 20 4 c and 22 4 c during the thanetian and between 23 3 c and 25 3 c during the sparnacian these giant birds likely lived under a warm and dry climate similar to that prevailing today in western mediterranean islands

assessment of telemac system performances a hydrodynamic case study of anglet france the wave propagation and flow modules of the telemac system have been applied to the adour river mouth and the adjacent beaches of anglet france the wave propagation has been simulated using the phase averaged model tomawac in addition the phase resolving refdif s model has been also used as the diffraction of wind waves which is not taken into account in tomawac can occur in the vicinity of the river mouth next the hydrodynamics has been simulated using the two dimensional depth averaged flow telemac 2d model the numerical results are compared with field measurements collected in march 2003 model performance statistics are calculated in order to assess the accuracy of the predictions at six locations regarding the computation of the wave propagation a root mean square error rmse is evaluated for the significant wave height the mean period and the peak direction of propagation for the flow computation a mean absolute error mae is used as it is applicable to vector quantities a classification is also adopted that categorises the quality of the results regarding the significant wave height the average relative rmse is of 18 2 for the tomawac computations whereas the error is of 30 8 for the refdif s simulations concerning the peak wave direction the rmse is about 10 both models predict the wave direction normal to the shore whereas the experimental parameters are more variable however the areas where energy concentrates are well reproduced the classification of errors shows that telemac 2d flow predictions are in a range from excellent to reasonable

observations and modeling of tsunami induced currents in ports and harbors abstract tsunamis or harbor waves in japanese are so named due to common observations of enhanced wave heights currents and damage in harbors and ports however dynamic currents induced by these waves while regularly observed and known to cause significant damage are poorly understood observations and modeling of the currents induced by the 2011 tohoku and 2004 indian ocean tsunamis allows us to show that the strongest flows in harbor basins are governed by horizontally sheared and rotational shallow features such as jets and large eddies when examining currents in harbors this conclusion will generally require a simulation approach that both includes the relevant physical processes in the governing equations and uses a numerical scheme that does not artificially damp these features without proper representation of the physics associated with these phenomena predictive models may provide drag force estimates that are an order of magnitude or more in error the immediate implementation of this type of analysis into tsunami hazard studies can mean the difference between an unaffected port and one in which 300 m long container vessels are detached from their moorings and drift chaotically

observed and modeled currents from the tohoku oki japan and other recent tsunamis in northern california we investigate the currents produced by recent tsunamis in humboldt bay and crescent city california the region is susceptible to both near field and far field tsunamis and has a historic record of damaging events crescent city harbor located approximately 100 kms north of humboldt bay suffered us 28 million in damages from strong currents produced by the 2006 kuril islands tsunami and an additional us 26 million from the 2011 japan tsunami in order to better evaluate these currents in northern california we deployed a nortek aquadopp 600 khz 2d acoustic doppler current profiler adcp with a 1 min sampling interval in humboldt bay near the existing national oceanic and atmospheric administration noaa national ocean service nos tide gauge station the instrument recorded the tsunamis produced by the mw 8 8 chile earthquake on february 27 2010 and the mw 9 0 japan earthquake on march 11 2011 one other tsunami was recorded on the humboldt bay tide gauge during the period of adcp operation but was not visible on the adcp suggesting a threshold water level value of about 0 2 m to produce an observable adcp record the 2010 tsunami currents persisted in humboldt bay for approximately 30 h with peak amplitudes of about 0 35 m s the 2011 tsunami signal lasted for over 40 h with peak amplitude of 0 84 m s the strongest currents corresponded to the maximum change in water level approximately 67 min after the initial wave arrival no damage was observed in humboldt bay for either event in crescent city currents for the first three and one half hours of the 2011 japan tsunami were estimated using security camera video footage from the harbor master approximately 70 m away from the noaa nos tide gauge station the largest amplitude tide gauge water level oscillations and most of the damage occurred within this time window the currents reached a velocity of approximately 4 5 m s and six cycles exceeded 3 m s during this period measured current velocities both in humboldt bay and in crescent city were compared to calculated velocities from the method of splitting tsunamis most numerical model the frequency and pattern of current amplification and decay at both locations are replicated by the most model for the first several hours after the tsunami onset most generally underestimates 2011 peak current velocities by about 10 30 with a few peaks by as much as 50 at humboldt bay most predicted attenuation of the signal after 4 h but the actual signal persisted at a nearly constant level for at least twice as long the results from this project demonstrate that adcps can effectively record tsunami currents for small to moderate events and can be used to calibrate and validate models i e most in order to better understand hazardous tsunami conditions within harbors

the march 11 2011 tōhoku m9 0 earthquake induced tsunami and coastal inundation along the japanese coast a model assessment abstract a high resolution nested global japan coastal fvcom system was used to simulate the march 11 2011 t hoku m9 earthquake induced tsunami waves and coastal inundation along the northeastern coast of honshu island in the western pacific ocean experiments were made with initial fields provided by five seismic rupture models under realistic conditions with inclusion of the kuroshio tides and wind forcing results show that the model computed intensities and distributions of tsunami waves and subsequent coastal inundation could be significantly influenced by initial conditions even though all five cases were capable of reproducing key features of the tsunami waves modeled tsunami waves featured a low dispersive weakly nonlinear long wave controlled by hydrostatic dynamics non hydrostatic effects only became significant when tsunami waves reached the inner shelf and the amplitude of the leading tsunami wave grew within o 1 of the local water depth 10 m or shallower in both hydrostatic and non hydrostatic cases significant mixing occurred when the ratio of wave amplitude to local water depth grew to about 0 25 or greater model predicted run up was in good agreement with 2 d n wave analytical solutions on the northern coast around south iwate where inundation was small but not in the central sendai coastal region where inundation was large and 3 d wave dynamics became significant the experiments suggest that once local bathymetry is accurately configured and the intensity and shape of the initial bottom movement can be predicted this nested fvcom system is capable of making accurate predictions of tsunami waves and coastal inundation

eocene oligocene mammalian faunal turnover in the hampshire basin uk calibration to the global time scale and the major cooling event a new high resolution c 1 ma mammalian record in continental eocene oligocene strata in the hampshire basin is used to investigate the nature and timing of the major europe wide mammalian faunal turnover termed the grande coupure whether this was caused by climate change or by competition with taxa dispersing from asia is controversial the mammalian faunas in this record after rarefaction analysis show a sharp reduction in diversity only after the grande coupure improved correlation of nw european successions to global events confirms the grande coupure as earliest oligocene it shows that a c 350 ka hiatus interrupts the hampshire and paris basin sequences prior to the first record of post grande coupure asian taxa hiatus bridging faunas from elsewhere in europe record mainly post grande coupure taxa suggesting that the turnover occurred early in the hiatus minimizing bias to the turnover pattern a previously unrecorded second smaller turnover involving european mammals only immediately precedes the grande coupure in the hampshire basin coinciding with vegetational change this turnover is judged not to represent cooling it is concluded that the grande coupure coincides with the earliest oligocene oi 1 glaciation and that climate change combined with competition to produce the turnover

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

buried relic seawall mitigates hurricane sandy s impacts abstract field observations to quantify damage overwash sediment deposition and breaching in the aftermath of hurricane sandy revealed clear differences in patterns of the impact between two neighboring boroughs along the new jersey shore bay head and mantoloking field data and observations gathered immediately after the storm indicate that a relic seawall in bay head appeared to lessen the wave driven effects of hurricane sandy as compared to its southern neighbor mantoloking complimentary detailed numerical simulations demonstrate that this relic seawall reduced the wave induced forces on ocean front structures indicated by wave averaged momentum flux by a factor of two the difference in impact of hurricane sandy between bay head and mantoloking underscores the urgent need for sustainable multi level protection against natural hazards in order to create resilient coastal communities

validating velocities in the geoclaw tsunami model using observations near hawaii from the 2011 tohoku tsunami the ability to measure predict and compute tsunami flow velocities is of importance in risk assessment and hazard mitigation substantial damage can be done by high velocity flows particularly in harbors and bays even when the wave height is small moreover advancing the study of sediment transport and tsunami deposits depends on the accurate interpretation and modeling of tsunami flow velocities and accelerations until recently few direct measurements of tsunami velocities existed to compare with model results during the 11 march 2011 tohoku tsunami 328 current meters were in place around the hawaiian islands usa that captured time series of water velocity in 18 locations in both harbors and deep channels at a series of depths we compare several of these velocity records against numerical simulations performed using the geoclaw numerical tsunami model based on solving the depth averaged shallow water equations with adaptive mesh refinement to confirm that this model can accurately predict velocities at nearshore locations model results demonstrate tsunami current velocity is more spatially variable than waveform or height and therefore may be a more sensitive variable for model validation

stratigraphic distribution of large flightless birds in the palaeogene of europe and its palaeobiological and palaeogeographical implications abstract the stratigraphic distribution of the three main groups of large flightless birds known from the palaeogene of europe gastornithidae phorusrhacidae and ratitae is reviewed the huge herbivorous gastornithids represented by the single genus gastornis are known from the selandian middle palaeocene to the late lutetian middle eocene being recorded from reference levels mp5 to mp13 the carnivorous phorusrhacids are represented by a single species eleutherornis cotei from the late lutetian mp14 late middle eocene the ratites have a patchy distribution being represented by two species of moderate size remiornis heberti from the thanetian mp6 late palaeocene and palaeotis weigelti from the lutetian mp11 to mp13 middle eocene the stratigraphic distributions of large eggs referred to gastornithids in the late palaeocene and early eocene of southern europe and the occurrence of enigmatic large avian footprints in the late eocene of france are discussed whereas gastornithids and ratites co existed in both the palaeocene and the middle eocene phorusrhacids seem to have been the only large ground birds in europe at the end of the middle eocene the palaeobiogeographical and evolutionary implications of the stratigraphic distributions of those groups of large birds in europe are discussed as gastornis first appears in north america and in asia in the early eocene it is likely that gastornithids originated in europe and later spread to other land masses during a dispersal event close to the palaeocene eocene boundary prior to that gastornithids evolved on the european island continent where they were the largest terrestrial tetrapods during the palaeocene gastornithids do not seem to have been significantly affected by the petm ratitae have a more patchy record and relationships between remiornis and palaeotis remain unclear nevertheless those european forms are among the earliest known ratites and this should not be overlooked in discussions of ratite evolution and palaeobiogeography phorusrhacids appear to have been present in europe for only a short time and are interpreted as the result of dispersal from africa followed by local extinction

waves and currents in hawaiian waters induced by the dispersive 2011 tohoku tsunami this study focuses on the effects of frequency dispersion on tsunami induced coastal water waves and currents exemplified by the 2011 tohoku tsunami event the investigation relies on numerical simulations we start from a tsunami source constrained through the inversion algorithm of noaa s tsunami inundation forecast system the trans pacific propagation and the hydrodynamic processes in the hawaiian islands region are simulated with a weakly dispersive boussinesq model and a shallow water model that neglects dispersion effects from these modeling results boundary conditions are derived to force the high resolution simulations in the coastal waters in the hawaiian islands region through most a tsunami simulating code based on the shallow water theory we note that the dispersion effects generally lower the amplitudes of leading waves trailing waves of short wavelengths and high amplitudes can develop in coastal waters a model neglecting dispersion effects could under predict the wave heights and current speeds at the trailing waves

morphotectonic segmentation of an active forearc 37 41 s chile abstract active forearc regions are characterized by seismo and morphotectonic segments that record recurrent seismic activity and subduction related tectonic deformation on different timescales however it is not well known on which timescales morphotectonic forearc segments retain their tectono geomorphic identity how they are related to earthquake rupture zones and what governs their long term evolution the forearc of the active convergent margin of south central chile 37 41 s is located within the rupture zone of the 1960 chile mw 9 6 megathrust earthquake in this region we combine geomorphological sedimentologic and morphometric dem analysis with compiled structural and geophysical data to reconstruct the morphotectonic evolution of the forearc the southern chile forearc comprises three segments nahuelbuta tolten and bueno segments that record a differential structural and geomorphic evolution whereas the tolten segment appears to be quasi stable the other two segments record pronounced ongoing quaternary uplift the nahuelbuta and bueno segments contain the n s oriented coastal cordillera characterized by numerous tectonically controlled drainage anomalies and evidence of sediment rerouting the morphotectonic segmentation appears to have persisted over timescales of 105 to 106 years importantly these segments do not correlate with earthquake rupture zones that exhibit a short term variability over 102 to 103 years thus earthquake rupture zones are transient second order phenomena which do not determine the long term morphotectonic forearc segmentation overall the differential forearc evolution and segmentation is influenced by a complex interplay of inherited upper plate structures and physical properties of the subducting oceanic nazca plate