the 2002 denali fault earthquake alaska a large magnitude slip partitioned event the mw moment magnitude 7 9 denali fault earthquake on 3 november 2002 was associated with 340 kilometers of surface rupture and was the largest strike slip earthquake in north america in almost 150 years it illuminates earthquake mechanics and hazards of large strike slip faults it began with thrusting on the previously unrecognized susitna glacier fault continued with right slip on the denali fault then took a right step and continued with right slip on the totschunda fault there is good correlation between geologically observed and geophysically inferred moment release the earthquake produced unusually strong distal effects in the rupture propagation direction including triggered seismicity

three dimensional finite difference modeling of the san andreas fault source parameterization and ground motion levels olsen et al 1995 recently simulated an mw 7 75 earthquake on the san andreas fault predicting long period t 2 5 sec ground velocities of 140 cm sec in the los angeles basin about 60 km from the fault these motions are much larger than estimates derived from empirical relations or other numerical simulations standard area magnitude relations predict that the 170 16 km fault used in the simulations would produce an mw 7 5 earthquake giving a moment of 2 0 1027 dyne cm which is 2 4 times smaller than the moment used by olsen et al 1995 further self similar scaling predicts a rise time of 3 sec for an mw 7 75 event and 2 2 sec for an mw 7 5 event the filtered impulse slip function used by olsen et al 1995 has an effective rise time of 1 6 sec yielding a response that is about 2 times larger than expected for periods less than 5 sec this combination of high seismic moment and short rise time along with the use of a uniform slip distribution leads to the extreme ground motion levels predicted by olsen et al 1995 to quantify the sensitivity of the long period ground motion response to source parameterization we have performed 3d finite difference fd simulations using various combinations of seismic moment source rise time and slip heterogeneity these calculations incorporate the same grid dimensions fault size and bandwidth employed by olsen et al 1995 with a moment of 2 0 1027 dyne cm a rise time of 2 sec and a smoothly heterogeneous slip distribution we simulate peak long period ground velocities of 155 cm sec in the near fault region and 40 cm sec in the los angeles basin these values are much closer to although still higher than empirical predictions a uniform slip distribution produces the largest peak motions both in the near fault region and in the los angeles basin whereas a rough asperity slip distribution noticeably reduces the maximum near fault ground velocities our results indicate that the accurate simulation of long period ground motions requires a realistic source parameterization including appropriate choices of seismic moment and rise time as well as the use of spatial and temporal variations in slip distribution

apatite weathering and the phanerozoic phosphorus cycle despite widespread debate in the literature there is still considerable uncertainty concerning which nutrient ultimately controls marine net ecosystem production nep over geologic time geochemical arguments suggest that phosphorus is the culprit the weathering of apatite the primary phosphorus sink in earth s exosphere controls long term phosphorus availability if phosphorus is the ultimate controlling nutrient over geologic time scales then long term marine nep is coupled to the release of phosphorus from apatite weathering the most abundant apatite compositions found in nature are igneous fluorapatite and marine sedimentary carbonate fluorapatite sparse data exist on how these compositions dissolve under earth s surface conditions to demonstrate a need for these data and their application we present a kinetic treatment of existing data augmented by new results we then use these results in a weathering model designed to illustrate the control exerted by temperature via activation energy and surface area on the phosphorus flux from apatite dissolution during the phanerozoic our conclusion is that activation energy and hence temperature and apatite surface area are important parameters governing the phosphorus flux from apatite weathering and therefore marine nep during phanerozoic time

terashake2 spontaneous rupture simulations of mw 7 7 earthquakes on the southern san andreas fault abstract previous numerical simulations terashake1 of large m w 7 7 southern san andreas fault earthquakes predicted localized areas of strong amplification in the los angeles area associated with directivity and wave guide effects from northwestward propagating rupture scenarios the terashake1 source was derived from inversions of the 2002 m w 7 9 denali alaska earthquake that source was relatively smooth in its slip distribution and rupture characteristics owing both to resolution limits of the inversions and simplifications imposed by the kinematic parameterization new simulations terashake2 with a more complex source derived from spontaneous rupture modeling with small scale stress drop heterogeneity predict a similar spatial pattern of peak ground velocity pgv but with the pgv extremes decreased by factors of 2 3 relative to terashake1 the terashake2 source excites a less coherent wave field with reduced along strike directivity accompanied by streaks of elevated ground motion extending away from the fault trace the source complexity entails abrupt changes in the direction and speed of rupture correlated to changes in slip velocity amplitude and waveform features that might prove challenging to capture in a purely kinematic parameterization despite the reduced pgv extremes northwest rupturing terashake2 simulations still predict entrainment by basin structure of a strong directivity pulse with pgvs in los angeles and san gabriel basins that are much higher than predicted by empirical methods significant areas of those basins have predicted pgv above the 2 probability of exceedance poe level relative to current attenuation relationships even when the latter includes a site term to account for local sediment depth and wave guide focusing produces localized areas with pgv at roughly 0 1 0 2 poe about a factor of 4 5 above the median in contrast at rock sites in the 0 100 km distance range the median terashake2 pgvs are in very close agreement with the median empirical prediction and extremes nowhere reach the 2 poe level the rock site agreement lends credibility to some of our source modeling assumptions including overall stress drop level and the manner in which we assigned dynamic parameters to represent the mechanical weakness of near surface material future efforts should focus on validating and refining these findings assessing their probabilities of occurrence relative to alternative rupture scenarios for the southern san andreas fault and incorporating them into seismic hazard estimation for southern california

simulations of ground motion in the los angeles basin based upon the spectral element method we use the spectral element method to simulate ground motion generated by two recent and well recorded small earthquakes in the los angeles basin simulations are performed using a new sedimentary basin model that is constrained by hundreds of petroleum industry well logs and more than 20 000 km of seismic reflection profiles the numerical simulations account for 3d variations of seismic wave speeds and density topography and bathymetry and attenuation simulations for the 9 september 2001 m w 4 2 hollywood earthquake and the 3 september 2002 m w 4 2 yorba linda earthquake demonstrate that the combination of a detailed sedimentary basin model and an accurate numerical technique facilitates the simulation of ground motion at periods of 2 sec and longer inside the basin model and 6 sec and longer in the regional model peak ground displacement velocity and acceleration maps illustrate that significant amplification occurs in the basin

estimation of strong ground motion from the great 1964 mw 9 2 prince william sound alaska earthquake we are generating physically plausible near field synthetic ground motions for the great 1964 prince william sound alaska earthquake compatible with available seismological data tectonic information and eyewitness accounts the first objective of this study is the simulation of the low frequency i e f 0 03 hz strong ground motions on selected locations and on a dense grid of observation points extending over the shallow dipping causative fault of the 1964 alaska earthquake in order to accomplish this task we are utilizing the slip model proposed by johnson et al 1996 based on a joint inversion of tsunami waveforms and geodetic data the calculations are carried out using the discrete wavenumber representation method bouchon and aki 1977 bouchon 1979 and the generalized transmission and reflection coefficient technique luco and apsel 1983 the second objective of this study is the reconstruction of the strong ground motion time histories and response spectra that the city of anchorage experienced during the 1964 alaska earthquake the low frequency i e f 0 03 hz ground motions are generated using the methodology described previously the intermediate frequency i e 0 03 f 0 50 hz ground motions are simulated by convolving green s functions generated by the discrete wavenumber representation method with far field radiation pulses of circular cracks sato and hirasawa 1973 dong and papageorgiou 2002a the high frequency i e 0 5 f 8 0 hz ground motions are simulated using the stochastic modeling approach the three independently derived ground motion components are then properly combined to generate synthetic broadband ground motion time histories and response spectra for the city of anchorage due to the 1964 prince william sound earthquake the third objective of this study is the validation of the synthetic strong ground motions for the 1964 alaska earthquake against observed tectonic deformation ground motion estimates inferred from descriptions of structural damage and eyewitness accounts in summary the analysis presented in this study contributes to a better understanding of the seismological aspects of the 1964 alaska earthquake and provides synthetic time histories and response spectra for engineering applications compatible with all available information i e seismological tectonic and eyewitness accounts it should be noted however that the generated strong ground motions are not necessarily unique nor do they reflect the entire uncertainty that characterizes the problem under investigation

erratum to active tectonics in central italy constraints from surface wave tomography and source moment tensor inversion phys earth planet inter 138 2003 241 262

fast kinematic waveform inversion and robustness analysis application to the 2007 mw 5 9 horseshoe abyssal plain earthquake offshore southwest iberia an m w 5 9 earthquake occurred beneath the horseshoe abyssal plain hap offshore southwest iberia on 12 february 2007 the region where the earthquake occurred has a high seismogenic and tsunamigenic potential the purpose of this paper is twofold 1 to extract information about the source of the earthquake that contributes to the understanding of regional tectonics and 2 to evaluate the applicability of a fast algorithm to study a moderate earthquake offshore mainland portugal we employed the kiwi tools which implement a multistep inversion algorithm to infer both the point and finite source properties of the earthquake in order to assess the robustness of our solutions we performed independent sets of inversions that take different datasets and assumptions e g green s functions passbands wave types as inputs we also performed bootstrap analyses in order to appraise the robustness of the source parameters we concluded that the 2007 hap earthquake centroid is located at 35 841 n 10 611 w at a depth of 39 km scalar moment m is consistently retrieved with an average value of graphic 1 moment magnitude m w 5 9 the finite fault parameters are difficult to resolve given the existing data approximately 70 of our bootstrap solutions indicate a true rupture plane that trends west northwest east southeast strike 128 dip 46 and rake 138 the location and strike of this fault plane coincide with the southwest iberian margin swim faults however the 46 dip is difficult to reconcile with the subvertical nature of the swim faults online material inversion results using teleseismic data prem and body waves only 1 embed inline graphic 1 gif

mantle heterogeneities and the scec reference three dimensional seismic velocity model version 3 we determine upper mantle seismic velocity heterogeneities below southern california from the inversion of teleseismic travel time residuals teleseismic p wave arrival times are obtained from three temporary passive experiments and southern california seismic network scsn stations producing good raypath coverage the inversion is performed using a damped least squares conjugate gradient method lsqr the inversion model element spacing is 20 km before the inversion the effects of crustal velocity heterogeneities represented by the southern california earthquake center scec seismic velocity model version 2 are removed from the teleseismic travel times the p wave inversion produces a variance reduction of 43 s wave velocities are determined from laboratory vp vs ratios the most prominent features imaged in the results are high p wave velocities 3 in the uppermost mantle beneath the northern los angeles basin and the previously reported tabular high velocity anomaly 3 to depths of 200 km beneath the transverse ranges crosscutting the san andreas fault we incorporate the upper mantle seismic velocity heterogeneities into the scec southern california reference seismic velocity model the prior accounting for the crustal velocity heterogeneity demonstrates the utility of the top down method of the scec seismic velocity model development

what the exercise of the spice source inversion validation blindtest 1 did not tell you summary uncertainties of earthquake finite fault inversions based upon strong motion data are investigated using the source inversion validation blindtest 1 exercise of the spice seismic wave propagation and imaging in complex media a european network project motivated by previous counterintuitive results the distribution of slip and the shapes of asymmetric slip rate functions are simultaneously inverted by matching 10 or 33 broad band three component velocity waveforms within the period ranging from 0 02 to 2hz using a finite fault method that carries out the waveform inversion in the wavelet domain the effects of subfault size data noise and the number of stations have been explored our results suggest 1 although there are inevitable discrepancies between the inverted model and the target model because of ignoring the spatial slip variations within individual subfaults the fault slip and rise time distributions can be well constrained even with the data including large gaussian noise 2 it is crucial for source studies to develop new inversion schemes that can properly honour the frequency and time dependent energy distribution of seismic radiation and data noise for instance inversions using the variance reduction function of velocity waveforms as the objective function have low sensitivities to the total seismic moment and peak slip 3 although the relative value of the objective function is guided in the inversion the absolute value of the objective function cannot be used to evaluate the quality of an inverted model 4 because the source inversion is based on surface observations the spatiotemporal resolution of source inversion is affected not only by the data quality but also by the earthquake itself for vertical strike slip faults the along strike resolution is better than that along the downdip direction

three dimensional simulation of a magnitude 7 75 earthquake on the san andreas fault simulation of 2 minutes of long period ground motion in the los angeles area with the use of a three dimensional finite difference method on a parallel supercomputer provides an estimate of the seismic hazard from a magnitude 7 75 earthquake along the 170 kilometer section of the san andreas fault between tejon pass and san bernardino maximum ground velocities are predicted to occur near the fault 2 5 meters per second and in the los angeles basin 1 4 meters per second where large amplitude surface waves prolong shaking for more than 60 seconds simulated spectral amplitudes for some regions within the los angeles basin are up to 10 times larger than those at sites outside the basin at similar distances from the san andreas fault

the 1994 northridge california earthquake investigation of rupture velocity risetime and high frequency radiation a hybrid global search algorithm is used to solve the nonlinear problem of calculating slip amplitude rake risetime and rupture time on a finite fault thirty five strong motion velocity records are inverted by this method over the frequency band from 0 1 to 1 0 hz for the northridge earthquake four regions of larger amplitude slip are identified one near the hypocenter at a depth of 17 km a second west of the hypocenter at about the same depth a third updip from the hypocenter at a depth of 10 km and a fourth updip from the hypocenter and to the northwest the results further show an initial fast rupture with a velocity of 2 8 to 3 0 km s followed by a slow termination of the rupture with velocities of 2 0 to 2 5 km s the initial energetic rupture phase lasts for 3 s extending out 10 km from the hypocenter slip near the hypocenter has a short risetime of 0 5 s which increases to 1 5 s for the major slip areas removed from the hypocentral region the energetic rupture phase is also shown to be the primary source of high frequency radiation 1 15 hz by an inversion of acceleration envelopes the same global search algorithm is used in the envelope inversion to calculate high frequency radiation intensity on the fault and rupture time the rupture timing from the low and high frequency inversions is similar indicating that the high frequencies are produced primarily at the mainshock rupture front two major sources of high frequency radiation are identified within the energetic rupture phase one at the hypocenter and another deep source to the west of the hypocenter the source at the hypocenter is associated with the initiation of rupture and the breaking of a high stress drop asperity and the second is associated with stopping of the rupture in a westerly direction

high resolution topography derived offsets along the 1857 fort tejon earthquake rupture trace san andreas fault the great fort tejon earthquake of 1857 with an 350 km long surface rupture was the most recent major earthquake along the south central san andreas fault saf prior reconstruction of its surface slip distribution and reconstruction of preceding earthquakes along the 1857 rupture trace have contributed to formulation of the characteristic earthquake cem and uniform slip models usm for earthquake recurrence that find wide application in seismic hazard assessment and earthquake forecasting we used the high resolution b4 light detection and ranging lidar topographic data set sufficient for depiction of meter scale tectonic landforms to reevaluate the distribution of surface displacement along the 1857 rupture trace we present 450 offset measurements with displacements below 60 m increasing observation density relative to previous studies by a factor of 2 our results show that the 1857 earthquake had overall an average displacement below 3 5 m with 4 6 m released along the northwestern half of the rupture its along fault slip distribution is smooth at 10 km length scales at 28 less than prior estimates assuming a 10 km rupture depth and a 30 gpa shear modulus reconstruction of pre 1857 earthquakes is impeded by an exponential decrease in observation density with increasing displacement amount offset observation density soon reaches a level where only tentative and nonunique reconstructions are permitted the results of this study question prior surface slipreconstructions of pre 1857 rupture s that were based on a distinctly lower number of offset observations challenging the applicability of the aforementioned earthquake recurrence models to explain saf rupture behavior online material catalog of offset measurements along the 1857 surface rupture trace as well as an annotated map 1 embed inline graphic 1 gif

response of high rise and base isolated buildings to a hypothetical mw 7 0 blind thrust earthquake high rise flexible frame buildings are commonly considered to be resistant to shaking from the largest earthquakes in addition base isolation has become increasingly popular for critical buildings that should still function after an earthquake how will these two types of buildings perform if a large earthquake occurs beneath a metropolitan area to answer this question we simulated the near source ground motions of a m w 7 0 thrust earthquake and then mathematically modeled the response of a 20 story steel frame building and a 3 story base isolated building the synthesized ground motions were characterized by large displacement pulses up to 2 meters and large ground velocities these ground motions caused large deformation and possible collapse of the frame building and they required exceptional measures in the design of the base isolated building if it was to remain functional

a geology based 3d velocity model of the los angeles basin sediments abstract seismic hazard studies of the los angeles basin area require a realistic seismic velocity model we use geologic information about depth to crystalline basement depths to sedimentary horizons uplift of sediments and surface geology in a velocity depth age function to construct a three dimensional velocity model in earthquake location tests the model predicts travel times satisfactorily and in earthquake ground motion simulations the model correctly determines the timing and amplitude of late arriving waves

case studies of damage to tall steel moment frame buildings in southern california during large san andreas earthquakes on 9 january 1857 a large earthquake of magnitude 7 9 occurred on the san andreas fault with rupture initiating at parkfield in central california and propagating in a southeasterly direction over a distance of more than 360 km such a unilateral rupture produces significant directivity toward the san fernando and los angeles basins indeed newspaper reports of sloshing observed in the los angeles river point to long duration 1 2 min and long period 2 8 sec shaking if such an earthquake were to happen today it could impose significant seismic demand on present day tall buildings using state of the art computational tools in seismology and structural engineering validated using data from the 17 january 1994 magnitude 6 7 northridge earthquake we determine the damage to an existing and a new 18 story steel moment frame building in southern california due to ground motion from two hypothetical magnitude 7 9 earthquakes on the san andreas fault our study indicates that serious damage occurs in these buildings at many locations in the region in one of the two scenarios for a north to south rupture scenario the peak velocity is of the order of 1 m sec 1 in the los angeles basin including downtown los angeles and 2 m sec 1 in the san fernando valley while the peak displacements are of the order of 1 m and 2 m in the los angeles basin and san fernando valley respectively for a south to north rupture scenario the peak velocities and displacements are reduced by a factor of roughly 2

p wave seismic velocity structure derived from sonic logs and industry reflection data in the los angeles basin california 1 we present a new three dimensional seismic p wave velocity model of the los angeles basin that is based on more than 150 sonic logs and 7000 stacking velocities from industry reflection profiles the model was developed using kriging techniques implemented in gocad a commercial application specializing in the construction of surfaces the analysis of spatially distributed data and the modeling or simulation of properties and is characterized by a heterogeneous spatial varying velocity gradient with maximum velocities of 5000 m s in the sedimentary section variability of the observed p wave velocities increases with depth reflecting complex structural and sedimentological controls the model contains a new representation of the basin shape as defined by the sediment basement interface which was mapped using well control and seismic reflection profiles our model differs substantially in approach and outcome from previous representations of crustal velocity structure in southern california

spectral element moment tensor inversions for earthquakes in southern california we have developed and implemented an automated moment tensor inversion procedure to determine source parameters for southern california earthquakes the method is based upon spectral element simulations of regional seismic wave propagation in an integrated 3d southern california velocity model sensitivity to source parameters is determined by numerically calculating the frechet derivatives required for the moment tensor inversion we minimize a waveform misfit function and allow limited time shifts between data and corresponding synthetics to accommodate additional 3d heterogeneity not included in our model the technique is applied to three recent southern california earthquakes the 9 september 2001 m l 4 2 hollywood event the 22 february 2003 m l 5 4 big bear event and the 14 december 2001 m l 4 0 diamond bar event using about half of the available three component data at periods of 6 sec and longer we obtain focal mechanisms depths and moment magnitudes that are generally in good agreement with estimates based upon traditional body wave and surface wave inversions

effects of large scale surface topography on ground motions as demonstrated by a study of the san gabriel mountains los angeles california we investigate the effects of large scale surface topography on ground motions generated by nearby faulting we show a specific example studying the effect of the san gabriel mountains which are bounded by the mojave segment of the san andreas fault on the north and by the los angeles basin on the south by si mulating a mw 7 5 earthquake on the mojave segment of the san andreas fault we show that the san gabriel mountains act as a natural seismic insulator for metropo litan los angeles the topography of the mountains scatters the surface waves gen erated by the rupture on the san andreas fault leading to less efficient excitation of basin edge generated waves and natural resonances within the los angeles basin the effect of the mountains reduces the peak amplitude of ground velocity for some regions in the basin by as much as 50 in the frequency band up to 0 5 hz these results suggest that depending on the relative location of faulting and the nearby large scale topography the topography can shield some areas from ground shaking

slip along the san andreas fault associated with the great 1857 earthquake historical records indicate that several meters of lateral slip along the san andreas fault accompanied the great 1857 earthquake in central and southern california these records together with dendrochronological evidence suggest that the rupture occurred along 360 to 400 km of the fault including several tens of kilometers of the currently creeping reach in central california geomorphic expressions of late holocene right lateral offsets are abundant along the 1857 rupture along 300 kilometers of the 1857 rupture between cholame and wrightwood the youngest discernible offset ranges from 3 to 9 1 2 meters dormancy of the fault since 1857 almost certainly indicates that this latest offset was created in 1857 fault slip apparently associated with the 1857 earthquake varies in a broadly systematic way along the trace of the fault it is relatively uniform along each of several long segments but changes rather abruptly in value between these segments this nonuniform displacement pattern may imply that some segments of the fault rupture more frequently or experience a slower long term slip rate than others the 1857 offsets indicate a seismic moment m o between 5 3 and 8 7 10 27 dyne cm assuming a 10 to 15 km depth of rupture and relatively uniform slip as a function of depth a comparison with the rupture length average slip value and tectonic setting of the california earthquake of 1906 m s 8 1 4 indicates a value of m 8 1 4 for the 1857 event

the scec southern california reference three dimensional seismic velocity model version 2 we describe version 2 of the three dimensional 3d seismic velocity model of southern california developed by the southern california earthquake center and designed to serve as a reference model for multidisciplinary research activities in the area the model consists of detailed rule based representations of the major southern california basins los angeles basin ventura basin san gabriel valley san fernando valley chino basin san bernardino valley and the salton trough embedded in a 3d crust over a variable depth moho outside of the basins the model crust is based on regional tomographic results the model moho is represented by a surface with the depths determined by the receiver function technique shallow basin sediment velocities are constrained by geotechnical data the model is implemented in a computer code that generates any specified 3d mesh of seismic velocity and density values this parameterization is convenient to store transfer and update as new information and verification results become available

earthquake hazards of active blind thrust faults under the central los angeles basin california we document several blind thrust faults under the los angeles basin that if active and seismogenic are capable of generating large earthquakes m 6 3 to 7 3 pliocene to quaternary growth folds imaged in seismic reflection profiles record the existence size and slip rates of these blind faults the growth structures have shapes characteristic of fault bend folds above blind thrusts as demonstrated by balanced kinematic models geologic cross sections and axial surface maps we interpret the compton los alamitos trend as a growth fold above the compton ramp which extends along strike from west los angeles to at least the santa ana river the compton thrust is part of a larger fault system including a decollement and ramps beneath the elysian park and palos verdes trends the cienegas and coyote hills growth folds overlie additional blind thrusts in the elysian park trend that are not closely linked to the compton ramp analysis of folded pliocene to quaternary strata yields slip rates of 1 4 0 4 mm yr on the compton thrust and 1 7 0 4 mm yr on a ramp beneath the elysian park trend assuming that slip is released in large earthquakes we estimate magnitudes of 6 3 to 6 8 for earthquakes on individual ramp segments based on geometric segment sizes derived from axial surface maps multiple segment ruptures could yield larger earthquakes m 6 9 to 7 3 relations among magnitude coseismic displacement and slip rate yield an average recurrence interval of 380 years for single segment earthquakes and a range of 400 to 1300 years for multiple segment events if these newly documented blind thrust faults are active they will contribute substantially to the seismic hazards in los angeles because of their locations directly beneath the metropolitan area

a methodology for seismic loss estimation in urban regions based on ground motion simulations seismic vulnerability assessment of residential buildings in regions of high seismicity is an interdisciplinary problem requiring major inputs from fields of seismology and earthquake engineering the basic two components of loss estimation methods are information on regional seismicity and building stock this study presents a realistic loss estimation methodology where the first component input ground motions is obtained from regional ground motion simulations using the stochastic finite fault technique the second component building vulnerability information on the other hand is taken into account using fragility analyses introducing the ground motion intensity parameters obtained from simulations to the fragility curves we obtain seismic loss distribution in a region in this study we demonstrate the loss estimation methodology with an application to three northwestern cities in turkey duzce bolu and kaynasli that experienced two major earthquakes graphic 1 and graphic 2 in less than three months in 1999 we initially verify the methodology with comparisons of observed and estimated damage ratios for the 12 november 1999 graphic 3 duzce earthquake later we present the estimated damage ratios under scenario earthquakes in the region for a magnitude range of graphic 4 graphic 5 is predicted to be the threshold magnitude for the cities of duzce and kaynasli where more than 60 of the building stock experience moderate and heavy damage because bolu is at a farther distance from the fault plane less damage is estimated for graphic 6 than those in the other centers for graphic 7 all three cities are predicted to experience substantial rates of heavy damage and collapse 1 embed inline graphic 1 gif 2 embed inline graphic 2 gif 3 embed inline graphic 3 gif 4 embed inline graphic 4 gif 5 embed inline graphic 5 gif 6 embed inline graphic 6 gif 7 embed inline graphic 7 gif