a referenced empirical ground motion model for arias intensity and cumulative absolute velocity based on the nga east databasea referenced empirical ground motion model for arias intensity and cumulative absolute velocity based on the nga east database

focal mechanisms of earthquakes related to the 29 november 1975 kalapana hawaii earthquake the effect of structure models initial focal mechanism determinations for the 29 november 1975 kalapana hawaii earthquake indicated discrepancy between the mechanism determined from teleseismic data by ando and the mechanism determined using data from the local u s geological survey network surrounding the epicenter region the resolution of this difference is crucial to correctly understand this earthquake as well as to understand the tectonics of the south flank of kilauea volcano when a model with a low velocity layer at the base of the crust is used for projection back to the focal sphere for the local network mechanisms the discrepancy vanishes to further investigate this result focal mechanisms were determined using several contrasting models for a set of well recorded earthquakes a large number of these earthquakes have mechanisms identical to the main shock when the low velocity layer model is used dispersion of p and t axes is also minimized by use of this model a low angle slip direction favored for the main shock and typical of most other solutions exhibits remarkable stability normal to the east rift zone of kilauea our results suggest a tectonic model similar in nature to that proposed by ando in which the south flank of kilauea consists of a mobile block of crust which is relatively free to move laterally on a low strength zone at about 10 km depth forceful injection of magma along the rift zones provides the loading stress which is released by catastrophic failure in the weak horizontal layer in a cycle of perhaps 100 yr

predictive model for seismic sliding displacement of slopes based on a coupled stick slip rotation approach abstract this paper represents a predictive model for the earthquake induced displacement of slopes using a coupled stick slip rotation approach recently proposed by the authors in a preceding paper a collection of 1363 strong motion records associated with 25 worldwide earthquakes was used to generate the model on the basis of results of sliding block analyses the proposed model predicts sliding displacement in terms of yield acceleration coefficient ratio ky kmax period ratio ts tm and slip length l the regression analysis indicates that dividing the results into the smaller intervals of period ratio can provide a noticeable higher degree of accuracy probable bias of the residuals versus the input variables is examined in detail predictions of the developed equation are compared with some available sliding block equations which similarly assumed a flexible sliding mass the proposed model can be simply used to estimate landslide hazard in seismic prone regions

last glacial holocene water structure in the southwestern okhotsk sea inferred from radiolarian assemblages abstract in order to reconstruct paleoceanographic conditions in the southwestern sw okhotsk sea radiolarian assemblages were analyzed from 10 surface sediments and 5 sediment cores obtained from various water depths ranging between 461 and 1348 m we also measured geochemical components such as biogenic opal calcium carbonate total organic carbon total sulfur and total nitrogen for one sediment core these data imply that the complicated water structure in the sw okhotsk sea changed with time from the last glacial to holocene the glacial surface water was characterized by low primary production in the summer and expanded sea ice coverage in the winter during this time the ventilation might have reached deeper than during the holocene during the major deglacial period including the melt water pulses 1a and 1b the deep sea oxygen content had declined with less ventilation and or more oxygen consumption with organic matter supply into the deeper depths the intermediate layer has been well ventilated and has supplied large amount of organic matter during the last 20 kyrs especially in the early mid holocene however such condition ceased during 3 to 2 ka the warm pacific deep water has been present since 9 ka the influence of warmer surface water such as the soya warm current swc increased in the coastal area during 7 to 4 ka and since 2 ka till present neritic derived productivity might be extended at 2 2 1 8 ka and since 1 2 ka till present

ground motion relations for eastern north america predictive relations are developed for ground motions from eastern north american earthquakes of 4 0 m 7 25 at distances of 10 r 500 km the predicted parameters are response spectra at frequencies of 0 5 to 20 hz and peak ground acceleration and velocity the predictions are derived from an empirically based stochastic ground motion model the relations differ from previous work in the improved empirical definition of input parameters and em pirical validation of results the relations are in demonstrable agreement with ground motions from earthquakes of m 4 to 5 there are insufficient data to adequately judge the relations at larger magnitudes although they are consistent with data from the saguenay m 5 8 and nahanni m 6 8 earthquakes the underlying model parameters are constrained by empirical data for events as large as m 6 8

new empirical relationships between arias intensity and peak ground acceleration abstract arias intensity i a and peak ground acceleration pga have been widely used as measures of the intensity of strong ground motions this study employs a large set of data consisting of 7034 horizontal and 3474 vertical strong motion records from 173 worldwide earthquakes m w 4 3 7 9 to refine the relationship between i a and pga and investigates its potential dependence on variables such as earthquake magnitude m w local site condition v s 30 focal mechanism and fault distance the dataset from the 2011 m w 9 0 tohoku earthquake and the 2013 m w 6 8 lushan earthquake is used to demonstrate the usability and necessity of our models the results reveal that the logarithm of i a increases linearly with the increase of the logarithm of pga and m w and the decrease of the logarithm of v s 30 and this kind of correlation is not significantly affected by focal mechanism and fault distance new global empirical relationships for both horizontal and vertical components are developed to estimate i a as a function of pga m w and v s 30 the resulting correlation equations presented in this article represent a significant advancement by incorporating such important features as magnitude and v s 30 and enable an improved way of estimating i a from pga online material table of earthquake parameters

hybrid empirical ground motion prediction equations for eastern north america using nga models and updated seismological parameters in the field of earthquake engineering ground motion prediction models are frequently used to estimate the peak ground acceleration pga and the pseudos pectral acceleration psa in regions of the world where ground motion recordings are plentiful such as western north america wna the ground motion prediction equations are obtained using empirical methods in other regions such as eastern north america ena with insufficient ground motion data alternative methods must be used to develop ground motion prediction equations gmpes the hybrid empiri cal method is one such method used to develop ground motion prediction equations in areas with sparse ground motions this method employs the stochastic simulation method to adjust empirical gmpes developed for a region with abundant strong motion recordings in order to estimate strong motion parameters in a region with a sparse database the adjustments take into account differences in the earthquake source wave propagation and site response characteristics between the two regions in this study a hybrid empirical method is used to develop a new gmpe for ena using five new ground motion prediction models developed by the pacific earthquake engineering research center peer for wna a new ena gmpe is derived for a magnitude range of 5 to 8 and closest distances to the fault rupture up to 1000 km ground motion prediction equations are developed for the response spectra pseudoacceleration 5 damped and the pga for hard rock sites in ena the resulting ground motion prediction model developed in this study is compared with two ena ground motion models used in the 2008 national seismic hazard maps as well as with available observed data for ena

an estimate of the absolute stress tensor in kaoiki hawaii the stress tensor orientation was calculated by inversion of 81 fault plane solutions of m 3 5 0 6 earthquakes located in an area 6 by 16 km at depths of 7 2 km this crustal volume is situated on a straight line between the summits of the active volcanoes kilauea and mauna loa the orientation of the greatest principal stress was found to be near horizontal and in the line connecting the two volcanoes this is further evidence supporting the model that magmatic expansion within the feeding conduits of these volcanoes is the source of stress that causes earthquakes in southern hawaii these earthquakes are tectonic earthquakes in the sense that they occur in a brittle elastic crust at distances of a few to several tens of kilometers from the volcanoes and that they are not directly associated with the opening of cracks by intrusions we propose that this model leads to the corollary that the shear stresses responsible for earthquake failure in the shallow hawaiian crust are approximately 3 2 mpa and that the pore pressure of ground water p in the hypocentral volume must be under near lithostatic pressure this result is obtained by arguing that the greatest principal stress 1 is equal to the magma pressure in the volcanic feeder pipe but cannot exceed the least principal stress 3 by more than the tensile strength of the crust because otherwise hydrofracture would occur opening a crack against the least principal stress given the difference between the greatest and least principal stress the fact that the overburden at the 7 km hypocentral depth equals the intermediate principal stress and the ratio r 1 2 1 3 0 4 which is obtained in the inversion of fault plane solutions we estimate that 1 202 mpa 2 200 mpa 3 196 mpa 3 mpa and n 199 mpa with uncertainties on the order of several mpa it follows that for any coefficients of friction larger than 0 15 the pore fluid pressure necessary for faulting on the observed fault planes has to be larger than 90 of the lithostatic pressure these considerations suggest that many earthquakes represent fault ruptures under low ambient shear stresses in the order of the average observed stress drop of 3 mpa

regionally adjustable generic ground motion prediction equation based on equivalent point source simulations application to central and eastern north america abstract we develop a generic ground motion prediction equation gmpe that can be adjusted for use in any region by modifying a few key model parameters the basis of the gmpe is an equivalent point source simulation model whose parameters have been calibrated to empirical data in california in such a way as to determine the decoupled effects of basic source and attenuation parameters on ground motion amplitudes we formulate the generic gmpe as a function of magnitude distance stress parameter geometrical spreading rate and anelastic attenuation this provides a fully adjustable predictive model allowing users to calibrate its parameters using observed motions in the target region we also include an empirical calibration factor to account for residual effects that are different from and or missing in simulations compared to observed motions in the target region as an example we show how the generic gmpe can be adjusted for use in central and eastern north america cena and calibrated with the next generation attenuation east database we provide median predictions of ground motions in cena for average horizontal component peak ground motions and 5 damped pseudospectral acceleration periods up to t 10 s for magnitudes m 3 8 and distances up to 600 km

site amplifications for generic rock sites seismic shear wave velocity as a function of depth for generic rock sites has been estimated from borehole data and studies of crustal velocities and these velocities have been used to compute frequency dependent amplifications for zero attenuation for use in simulations of strong ground motion we define a genetic rock site as one whose velocity at shallow depths equals the average of those from the rock sites sampled by the borehole data most of the boreholes are in populated areas for that reason the rock sites sampled are of particular engineering significance we consider two genetic rock sites rock corresponding to the bulk of the borehole data and very hard rock such as is found in glaciated regions in large areas of eastern north america or in portions of western north america the amplifications on rock sites can be in excess of 3 5 at high frequencies in contrast to the amplifications of less than 1 2 on very hard rock sites the consideration of unattenuated amplification alone is computationally convenient but what matters for ground motion estimation is the combined effect of amplification and attenuation for reasonable values of the attenuation parameter k 0 the combined effect of attenuation and amplification for rock sites peaks between about 2 and 5 hz with a maximum level of less than 1 8 the combined effect is about a factor of 1 5 at 1 hz and is less than unity for frequencies in the range of 10 to 20 hz depending on t using these amplifications we find provisional values of about ao 70 bars and k 0 0 035 sec for rock sites in western north america by fitting our empirically determined response spectra for an m 6 5 event to simulated values the borehole data yield shear velocities 033o of 618 and 306 rrdsec for rock and soil sites respectively when averaged over the upper 30 m from this we recommend that v30 equals 620 and 310 m sec for applications requiring the average velocity for rock and soil sites in western north america by combining the amplifications for rock sites and the site factors obtained from our analysis of strong motion data we derive amplifications for sites with 17 3o 520 m sec nehrp class c corresponding to a mix of rock and soil sites and v3o 310 and 255 m sec average soil and nehrp class d sites respectively for the average soil site the combined effect of amplification and attenuation exceeds a factor of 2 0 for frequencies between 0 4 and about 4 hz with a peak site effect of 2 4 the peak of the nehrp class d site effect is 2 7

reply to comment on a single force model for the 1975 kalapana hawaii earthquake by holly k eissler and hiroo kanamori we showed that the long period seismic radiation from the november 29 1975 kalapana hawaii earthquake which involved seaward displacement of the south flank of kilauea volcano was best explained by invoking a near horizontal single force as the kinematic source of the earthquake eissler and kanamori 1987 in particular the azimuthal dependence of 100 s love surface waves is difficult to explain by a conventional double couple source the unusual love wave pattern was noted by ando 1979 but not explained until our suggestion of the single force source model

motions of gently sloping ground during earthquakes 1 during past earthquakes gently sloping ground surfaces have been observed to shift laterally over areas as large as a few square kilometers these permanent downward motions have been attributed to temporary and partial reductions in shear strength of soil deposits e g liquefaction static gravity forces and transient earthquake shakings these motions the amplitudes of which remain challenging to predict have been frequently modeled using newmark sliding blocks for ground that is statically stable and occasionally partially or completely loses its shear strength during earthquakes this paper investigates in more details the deformations of gently sloping ground that becomes temporarily unstable under the combined effects of gravitational forces and earthquake shakings using a physical model we propose two definitions of earthquake contributions to the displacement of gently sloping ground which may include or not the effects of initial velocity in both cases monte carlo simulations reveal that motions of gently sloping ground are influenced by pulses of earthquake ground velocity for a wide range of reduction in soil shear strength even for very severe loss of shear strength for practical purposes when large soil deposits become unstable during earthquakes the analysis concludes that the motions of gently sloping ground are likely influenced by earthquake ground velocity

ground motion prediction equations for eastern north america from a referenced empirical approach implications for epistemic uncertainty abstract i outline a referenced empirical approach to the development of ground motion prediction equations gmpes the technique is illustrated by using it to develop gmpes for eastern north america ena the approach combines the ena ground motion database with the empirical prediction equations of boore and atkinson 2008 for the reference region of western north america wna the referenced empirical approach provides gmpes for ena that are in agreement with regional ground motion observations while being constrained to follow the overall scaling behavior of ground motion that is observed in better instrumented active tectonic regions they are presented as an alternative to the commonly used stochastic ground motion relations for ena the motivation of the article is not to supplant stochastic gmpes but is rather to consider other approaches that might shed light on their epistemic uncertainty differences between the referenced empirical gmpes of this study and the stochastic gmpes of atkinson and boore 2006 along with inconsistencies between both of these studies and inferences based on intensity observations suggest that uncertainty in median enagmpes is about a factor of 1 5 2 for m 5 at distances from 10 to 70 km uncertainty is greater than a factor of 2 for large events m 7 at distances within 10 km of the source it may be that saturation effects not modeled in the stochastic predictions but inferred from observations in other regions cause overestimation of near source amplitudes from large events in atkinson and boore 2006 on the other hand these saturation effects cannot be directly verified in ena data differences in predictions according to the approach taken are also significant at distances from 40 to 150 km due to uncertainty in the shape of the attenuation function that will be realized in future earthquakes

assessment of liquefaction potential during earthquakes by arias intensity an arias intensity approach to assess the liquefaction potential of soil deposits during earthquakes is proposed using an energy based measure of the severity of earthquake shaking recorded on seismograms of the two horizontal components of ground motion values representing the severity of strong motion at depth in the soil column are associated with the liquefaction resistance of that layer as measured by in situ penetration testing spt cpt this association results in a magnitude independent boundary that envelopes initial liquefaction of soil in arias intensity normalized penetration resistance space the arias intensity approach is simple to apply and has proven to be highly reliable in assessing liquefaction potential the advantages of using arias intensity as a measure of earthquake shaking severity in liquefaction assessment are arias intensity is derived from integration of the entire seismogram wave form incorporating both the amplitude and duration elements of ground motion all frequen

empirical stochastic ground motion prediction for eastern north america an alternative approach based on a hybrid empirical model is utilized to predict the ground motion relationship for eastern north america ena in this approach a stochastic model is first used to derive modification factors from the ground motions in western north america wna to the ground motions in ena the ground motion parameters are then estimated to develop an empirical attenuation relationship for ena using empirical ground motion relationships from wna w e develop an empirical stochastic source model for both regions to obtain ground mo tions at different magnitude distance range of interest at short distances r 30 km and large magnitudes mw 6 4 an equivalent point source model is carried out to consider the effect of finite fault modeling on the ground motion parameters source focal depth and brune stress drop are assumed to be magnitude dependent we choose three well defined empirical attenuation relationships for wna to com pare the empirical ground motion processes between the two regions a composite functional attenuation form is defined and in turn a nonlinear regression analysis is performed by using a genetic algorithm ga for a wide range of magnitudes and distances to develop an empirical attenuation relationship from the stochastic ground motion estimates in ena the empirical stochastic attenuation relationship for hor izontal peak ground acceleration and spectral acceleration are applicable to earth quakes of mw 5 0 8 2 at distances of up to 1000 km the resulting attenuation model developed in this study is compared with those used in the 2002 national seismic hazard maps derived in the 2003 electric power research institute studies and re corded in ena the comparison of the results to the other attenuation functions and the available ena data show a reasonable agreement for the ena ground motions

centroid single force inversion of seismic waves generated by landslides the centroid moment tensor cmt waveform inversion method of dziewonski et al 1981 is modified to analyze long period seismic waves generated by single force events such as the gigantic landslides associated with the 1980 eruption of mount st helens we refer to the method as centroid single force csf inversion as the result of the inversion we obtain the spatio temporal centroid and three components of a vector we call the csf vector which is the seismic point source representation of a landslide and whose direction is the opposite of the direction of sliding the sealer magnitude of the csf vector measures the overall size of the landslide and is given by mcsf md where m is the mass of the sliding object and d is the sliding distance we apply csf inversion to the long period surface waves generated by the 1980 mount st helens event the 1975 kalapana earthquake and the 1974 mantaro landslide using seismograms from the gdsn ida and hglp networks the csf solution for the st helens event is remarkably consistent with the actual geological observations and proves the efficacy of csf inversion the csf solution for the kalapana event does not fit the overall waveforms better than the cmt solution does however because the cmt solution does not explain the observed love wave radiation pattern it may be necessary to invoke a combination of both types of mechanism for this event although the geometry of the csf solution the direction of the force for the mantaro event is consistent with the actual landslide mcsf is about 5 times smaller than that expected from the mass and travel distance of the landslide estimated by geological observations this discrepancy may suggest either the relatively aseismic nature of this landslide or that the total volume of the slide was overestimated by analogy to single station cmt inversion single station csf inversion also appears to be stable and useful

analysis of long period seismic waves excited by the may 18 1980 eruption of mount st helens a terrestrial monopole long period 100 to 260 s love and rayleigh waves excited by the eruption of mount st helens on may 18 1980 and recorded by ida sro and asro stations were analyzed to determine the mechanism of the eruption the amplitude radiation patterns of both rayleigh and love waves are two lobed with a nodal direction in e5 s for rayleigh waves and in n5 e for love waves these radiation patterns preclude any double couple mechanism the radiation pattern the initial phase the relatively large amplitude ratio of love to rayleigh waves and the existence of clear nodes in the radiation patterns of fundamental mode and higher mode rayleigh waves suggest that the source is represented by an almost horizontal less than 15 from the horizontal single force pointed toward s5 w the surface wave spectra fall off very rapidly at periods shorter than 75 s suggesting a very slow source process although the details of the source time history could not be determined a smooth bell shaped time function f o s t 1 2 f o l cos t for 0 t 2 and f o s t 0 for t 2 with 75 s is considered appropriate on the basis of comparison between synthetic and observed seismograms and of the shape of the source spectrum the peak value of the force f 0 is about 10 18 dynes the tailing end of the source time function could not be resolved and some overshoot may be added the magnitude and the time history of the force can be explained by a northward landslide followed by a lateral blast observed at the time of the eruption two distinct events about 110 s apart can be identified on body wave and short period surface wave records the first event may correspond to the earthquake which triggered the landslide and the lateral blast the second event appears to correspond to a second large earthquake and explosion which took place about 2 minutes after the first earthquake

simulation of earthquake ground motions in the eastern united states using deterministic physics based and site based stochastic approaches abstract earthquake ground motion recordings are scarce in the central and eastern united states ceus for large magnitude events and at close distances we use two different simulation approaches a deterministic physics based method and a site based stochastic method to simulate ground motions over a wide range of magnitudes drawing on previous results for the modeling of recordings from the 2011 m w 5 8 mineral virginia earthquake and using the 2001 m w 7 6 bhuj india earthquake as a tectonic analog for a large magnitude ceus event we are able to calibrate the two simulation methods over this magnitude range both models show a good fit to the mineral and bhuj observations from 0 1 to 10 hz model parameters are then adjusted to obtain simulations for m w 6 5 7 0 and 7 6 events in the ceus our simulations are compared with the 2014 u s geological survey weighted combination of existing ground motion prediction equations in the ceus the physics based simulations show comparable response spectral amplitudes and a fairly similar attenuation with distance the site based stochastic simulations suggest a slightly faster attenuation of the response spectral amplitudes with distance for larger magnitude events and as a result slightly lower amplitudes at distances greater than 200 km both models are plausible alternatives and given the few available data points in the ceus can be used to represent the epistemic uncertainty in modeling of postulated ceus large magnitude events

representative seismic hazard map of coimbatore india the seismic hazard value of any region depends upon three important components such as probable earthquake location maximum earthquake magnitude and the attenuation equation this paper presents a representative way of estimating these three important components considering region specific seismotectonic features rupture based seismic hazard analysis rbsha given by anbazhagan et al 2011 is used to determine the probable future earthquake locations this approach is verified on the earthquake data of bhuj region the probable earthquake location for this region is identified considering earthquake data till the year 2000 these identified locations match well with the reported locations after 2000 the further coimbatore city is selected as the study area to develop a representative seismic hazard map using rbsha approach and to compare with deterministic seismic hazard analysis probable future earthquake zones for coimbatore are located considering the rupture phenomenon as per energy release theory discussed by anbazhagan et at 2011 rupture character of the region has been established by estimating the subsurface rupture length of each source and normalized with respect to the length of the source average rupture length of the source with respect to its total length is found to be similar for most of the sources in the region which is called as the rupture character of the region maximum magnitudes of probable zones are estimated considering seismic sources close by and regional rupture character established representative gmpes for the study area have been selected by carrying out efficacy test through an average log likelihood value llh as ranking estimator and considering the isoseismal map new seismic hazard map of coimbatore has been developed using the above regional representative parameters of probable earthquake locations maximum earthquake magnitude and best suitable gmpes the new hazard map gives acceleration values at bedrock for maximum possible earthquakes these results are compared with deterministic seismic hazard map and recently published probabilistic seismic hazard values c 2014 elsevier b v all rights reserved

the silica cycle during the last ice age abstract qualitative and quantitative investigations of the silica geochemistry in the ocean and its cycles and changes during the quaternary have been carried out based on more than 4000 sample determinations the present si cycle within the ocean balance and annual silica accumulation were determined the main part of silica has accumulated on the ocean bottom in three silica accumulation belts southern equatorial and northern the changes of the belts were synchronous for the northern and the southern hemispheres and were caused by climatic changes connected with glaciation

empirical attenuation of ground motion spectral amplitudes in southeastern canada and the northeastern united states a database of 1700 digital seismograms from 186 earthquakes of mag nitude mn 2 5 5 6 that occurred in southeastern canada and the northeastern united states from 1990 to 2003 was compiled maximum likelihood regression analysis of the database was performed to determine a model for the attenuation of fourier spectral amplitudes for the shear window for the vertical and horizontal component of motion for frequencies from 0 2 to 20 hz fourier amplitudes follow a hinged trilinear attenuation model fourier spectral amplitudes decay as r 1 3 where r is hypocentral distance within 70 km of the source there is a transition zone from 70 to 140 km as the direct waves are joined by strong postcritical reflections where the attenuation is described as r 0 2 spectral amplitudes actually increase with distance in this range for low frequencies beyond 140 km the attenuation is well described by r 0 5 corresponding to geometric spreading in two dimensions the associated model for the regional quality factor for frequencies greater than 1 hz can be ex pressed as q 893f 032 q can be better modeled over a wider frequency range 0 2 20 hz by a polynomial expression log q 3 052 0 393 log f 0 945 log f 2 0 327 log f 3 the polynomial expression accommodates the observation that q values are at a minimum about 1000 near 1 hz and rise at both lower and higher frequencies correction factors for the spectral amplitude model that describe the effects of focal depth on the amplitudes and their attenuation are developed using the subset of events with known focal depth the attenuation model is similar to that determined from an earlier study with more limited data atkinson and mereu 1992 but the enlarged database indicates more rapid near source amplitude decay and higher q the attenuation model is used to play back attenuation effects to determine the apparent source spectrum for each earthquake in the database and hence determine moment magnitude m and brune stress drop the events have moment magnitude in the range from 2 5 to 5 stress drop increases with moment magnitude for events of m 4 3 then appears to attain a relatively constant level in the range from 100 to 200 bars for the larger events as previously noted in atkinson 1993b the results of this study provide a useful framework for improving regional ground motion relations in eastern north america they further our understanding of attenuation in the region through analysis of an enlarged ground motion database in particular the inclusion of the three component broadband data gathered over the last decade allows extension of attenuation models to both horizontal and vertical components over a broad frequency range 0 2 20 hz

ground motion models for seismic hazard assessment in western iberia constraints from instrumental data and intensity observations abstract the lack of constraints regarding ground motion propagation characteristics in western iberia remains one of the major hindrances to accurate seismic hazard and seismic risk assessment in the region the fact that western iberia is geographically located near the confluence of oceanic crust active continental crust and stable continental crust further complicates the selection of appropriate ground motion models to address this question we compare through visual inspection and residual analysis the regional ground motion data for moderate magnitude earthquakes with a set of six ground motion prediction equations some of which were developed for active tectonic regions and the others for stable continental regions although the available data pertain mostly to offshore moderate magnitude earthquakes m 4 8 6 0 at large distances 100 400 km the few records from an onshore m 4 0 earthquake and from the 1969 m 7 8 earthquake display similar trends the results show that the performance of the models is period dependent with shorter spectral periods 0 01 s 0 1 s 0 2 s and 0 5 s being strongly underpredicted by models developed for shallow active tectonic regions more interestingly the performance of the models for stable continental regions seems to be magnitude dependent with response spectra amplitudes for magnitudes of engineering interest being accurately estimated by the models the inspection of the residual distributions of intensity observations leads to similar conclusions for the offshore data while highlighting the extent of epistemic uncertainty in predicting the ground motions for moderate magnitude earthquakes at short to moderate distances

holocene upper pleistocene radiolarian biogeography and paleoecology of the equatorial pacific abstract polycystine radiolarians were investigated in 66 samples from 5 box cores spanning the last ca 40 000 years from the western approx 160 e and the central 136 w equatorial pacific the assemblages investigated show clear differences associated with the geographic locations of the sites the central pacific is characterized by higher specific diverities much higher absolute abundances of shells per gram of dry bulk sediment and by conspicuously better radiolarian preservation the differences involved also include significant changes in the relative proportions of several radiolarian species these accounting for approx 25 of total individuals families and orders these dissimilarities are chiefly attributed to differences in the primary production of the two zones and to enhanced advection of colder water species characteristics of the california current to the central equatorial pacific in both areas downcore faunal changes if present at all are so weak that background noise from random sample to sample variations almost completely masks them there do not seem to be any noticeable shifts associated with the 18 k y level inconclusive evidences of environmental changes at 30 20 k y b p are suggested in some of the cores by the increase in the proportions of several species characteristic of colder northeastern pacific waters and by lower radiolarian accumulation rates these changes seem to be paralleled by shifts in the isotopic composition of planktonic foraminifera

seismic triggering of catastrophic failures on shear surfaces in saturated cohesionless soils this paper is concerned with an analysis of the seismic performance of infinite slopes in undrained conditions the material assumed on the sliding surface is a loose saturated sand susceptible to a gradual loss in undrained shear strength after failure with the progress of unidirectional shear displacement the undrained monotonic and cyclic shear behavior of this sand was investigated through an experimental study based on ring shear tests with initial stresses corresponding to the static conditions on the sliding surface of the analyzed slopes these tests provide the experimental framework for a modified sliding block method to estimate the earthquake induced undrained shear displacements for conditions of no shear stress reversals on the sliding surface the proposed estimation procedure incorporates the shearing resistance obtained from undrained monotonic ring shear tests to approximate the undrained yield resistance at a certain displacement during an earthquake the term catastrophic failure is

spatial variability and attenuation of arias intensity during the 1999 chi chi mw 7 6 earthquake taiwan arias intensity is a measure of earthquake intensity that captures the potential destructiveness of an earthquake using the strong ground motion records of the m w 7 6 chi chi earthquake taiwan we analyze the spatial distribution of the vertical horizontal fault parallel and fault normal components of the arias intensity we investigate the effects of the hanging wall and footwall on ground motions and develop a relationship between arias intensity and peak ground acceleration pga incorporating the influence of local site conditions we also evaluate the applicability of some widely used arias intensity attenuation relationships by comparing the observed values with empirical estimates our results show the vertical arias intensity is generally lower than the horizontal component with nearly 90 of the vertical to horizontal ratios between 0 1 and 0 6 during this typical reverse mechanism earthquake the fault normal component of the arias intensity is approximately 20 higher than the fault parallel component for sites within 40 km of the fault arias intensities on the hanging wall are systematically higher than those on the footwall indicating clear hanging wall effects site conditions influence the correlation between arias intensity and pga arias intensity shows a good correlation with pga and v s 30 arias intensity increases with increasing pga and decreasing v s 30 the arias intensities observed within 40 km of site class c locations and within 80 km of site class d locations are generally lower than the mean estimates from empirical predictions in contrast at distances of 80 km from site class d locations the observed arias intensities are much larger than the empirical predictions as a result of site amplification considering the variability of ground motion between earthquakes the attenuation model of travasarou et al 2003 model 4 of stafford et al 2009 and the model of lee et al 2012 provide a good fit with observations from the chi chi earthquake online material table of station coordinates fault distances footwall hanging wall indicator site classes v s 30 and measured arias intensities

a κ model for mainland france an important parameter for the characterization of strong ground motion at high frequencies 1 hz is kappa which models a linear decay of the acceleration spectrum a f in log linear space i e a f a 0 exp f for f f e where f is frequency f e is a low frequency limit and a 0 controls the amplitude of the spectrum is a key input parameter in the stochastic method for the simulation of strong ground motion which is particularly useful for areas with insufficient strong motion data to enable the derivation of robust empirical ground motion prediction equations such as mainland france numerous studies using strong motion data from western north america wna an active tectonic region where surface rock is predominantly soft and eastern north america ena a stable continental region where surface rock is predominantly very hard have demonstrated that varies with region and surface geology with wna rock sites having a of about 0 04 s and ena rock sites having a of about 0 006 s lower s are one reason why high frequency strong ground motions in stable regions are generally higher than in active regions for the same magnitude and distance few if any estimates of s for french sites have been published therefore the purpose of this study is to estimate using data recorded by the french national strong motion network rap for various sites in different regions of mainland france for each record a value of is estimated by following the procedure developed by anderson and hough bull seismol soc am 74 1969 1993 1984 this method is based on the analysis of the s wave spectrum which has to be performed manually thus leading to some uncertainties for the three french regions where most records are available the pyrenees the alps and the cotes d azur a regional model is developed using weighted regression on the local geology soil or rock and source to site distance it is found that the studied regions have a mean between the values found for wna and ena for example for the alps region a value of 0 0254 s is found for rock sites an estimate reasonably consistent with previous studies

evaluation of ground motion models for usgs seismic hazard forecasts induced and tectonic earthquakes in the central and eastern united statesevaluation of gmms for usgs seismic hazard forecasts

modifications to existing ground motion prediction equations in light of new data we compare our recent ground motion prediction equations gmpes for western north america wna boore and atkinson 2008 ba08 and eastern north america ena atkinson and boore 2006 ab06 atkinson 2008 a08 to newly available ground motion data based on these comparisons we suggest revisions to our gmpes for both wna and ena the revisions for wna affect only those events with m 5 75 while those for ena affect all magnitudes these are simple modi fications to the existing gmpes that bring them into significantly better agreement with data the wealth of new data clearly demonstrates that these modifications are warranted we therefore recommend the use of the updated equations for seismic hazard analyses and other applications more detailed studies are under way by many investigators including ourselves to develop a new generation of ground motion models in both wna and ena from scratch through a comprehensive reevaluation of source path site and modeling issues in time those more complete models will replace those proposed in this study however as the new models will be several years in development we recommend using the modified models proposed herein labeled ba08 for wna ab06 for ena and a08 for ena to replace a08 as interim updates to our existing models the proposed models are in demonstrable agreement with a rich database of ground motions for moderate magnitude earthquakes in both wna and ena and are constrained at larger magnitudes by the ba08 magnitude and distance scaling

comment on a single force model for the 1975 kalapana hawaii earthquake by holly k eissler and hiroo kanamori

earthquake source spectra in eastern north america source spectra for earthquakes of 3 m 7 in eastern north america ena are determined from regional seismograph recordings strong motion records teleseismic data and modified mercalli intensity data the inclusion of mmi data is made possible by the finding that the felt area of an earthquake is an accurate measure of its high frequency spectral level at the source current ground motion relations for ena are based on a brune source model with a stress parameter of 100 bars this model is a poor fit to ena source spectra for events of m 4 at high frequencies 5 to 10 hz observed spectral amplitudes are more nearly matched by a brune stress parameter of 200 bars intermediate frequency amplitudes near 1 hz are matched by a stress parameter of approximately 50 bars an empirical two corner source model is proposed to describe ena source spectra for events of 4 m 7

regression models for estimating coseismic landslide displacement newmark s sliding block model is widely used to estimate coseismic slope performance early efforts to develop simple regression models to estimate newmark displacement were based on analysis of the small number of strong motion records then available the current availability of a much larger set of strong motion records dictates that these regression equations be updated regression equations were generated using data derived from a collection of 2270 strong motion records from 30 worldwide earthquakes the regression equations predict newmark displacement in terms of 1 critical acceleration ratio 2 critical acceleration ratio and earthquake magnitude 3 arias intensity and critical acceleration and 4 arias intensity and critical acceleration ratio these equations are well constrained and fit the data well 71 br 2 b88 but they have standard deviations of about 0 5 log units such that the range defined by the mean one standard deviation spans about an order of magnitude these regression models therefore are not recommended for use in site specific design but rather for regional scale seismic landslide hazard mapping or for rapid preliminary screening of sites 2007 elsevier b v all rights reserved

certain aspects of radiolarian data as evidence of the paleoenvironment abstract different aspects of the ecology and biogeography of radiolarians are considered as a means of interpreting the paleoenvironment the quantitative and spatial distribution of radiolarians in the sediments of the world ocean are discussed including differences between marine and oceanic thanatocoenoses relations between species and high rank associations of radiolarians and fluctuation of climate areal changes of some species with time etc

seismic hazard map of southeast missouri and likely magnitude of the february 1812 new madrid earthquake abstract the new madrid seismic zone lies beneath the upper mississippi embayment straddling the border between southeastern missouri and northwestern tennessee in late 1811 and early 1812 it produced five earthquakes of magnitudes 6 5 violently shaking the central and eastern united states ceus its magnitude and recurrence are of concern to today s central united states regions by considering the effects of local geology deterministic scenario maps m w 7 3 and 7 7 were produced for ground motions intended to simulate the 7 february 1812 event nm3 which was the largest felt these maps include spatial estimates of peak ground acceleration and of 0 2 s and 1 0 s spectral acceleration sa compared with the isoseismic map of modified mercalli intensities mmis in southeast missouri the mmis converted from 0 2 s sa suggest that m w 7 7 is a plausible scenario for nm3 to better constrain its magnitude other ceus sites shaken during nm3 were also examined local site conditions were studied and evaluated before calculating the threshold magnitude for the reported mmis these results indicate that the magnitude of nm3 was at least m w 7 6 which validates our estimated size of m w 7 7 for southeastern missouri

comparison of a complex rupture model with the precursor asperities of the 1975 hawaii m s 7 2 earthquake a simplified multiple source model was constructed for the 1975 hawaiims 7 2 earthquake by matching synthetic signals with three component accelerograms at two stations located approximately 45 km from the epicenter six major subevents were identified and located approximately the signals of these are larger by factors of 1 4 to 3 2 than that of theml 5 9 foreshock which occurred 70 minutes before the main rupture and also triggered the sam 1 recorders at the two stations dividing the rupture length 40 km by the duration of strong ground shaking 50 sec an average rupture velocity of 0 8 km sec about 25 of s velocity is obtained thus it is likely that the rupture stopped between subevents the approximate epicenters of the 6 major subevents and of the foreshock support the hypothesis that they were located in high stress asperities which rupture during the main shock except for the last events which is interpreted as a stopping phase generated at a barrier these asperities have been previously defined on the basis of differences in the precursor pattern before the mainshock thus it appears that both the details of the precursors and of the main rupture depended critically on the heterogeneous tress distribution in the source volume this suggests that main rupture initiation points and locations of high rupture accelerations may be identified before the mainshock occurs based on precursor anomaly patterns a satisfactory match of synthetic signals with the observations could be obtained only if the aximuth of the fault plane of subevents was rotated from n60 e to n90 e and back to n30 e these orientations are approximately parallel to the nearest kilauea rift segments hence the slip directions and greatest principal stresses were oriented perpendicular to the rifts everywhere from this analysis and other work it is concluded that this fault surface consisted of three types of segments with different strength hard asperities radius 5 km soft but brittle segments between the asperities radius 5 km and a viscous half 10 40 km which slipped during the mainshock but where microearthquakes and aftershocks are not common

earthquake ground motion prediction equations for eastern north america new earthquake ground motion relations for hard rock and soil sites in eastern north america ena including estimates of their aleatory uncertainty vari ability have been developed based on a stochastic finite fault model the model incorporates new information obtained from ena seismographic data gathered over the past 10 years including three component broadband data that provide new in formation on ena source and path effects our new prediction equations are similar to the previous ground motion prediction equations of atkinson and boore 1995 which were based on a stochastic point source model the main difference is that high frequency amplitudes f 5 hz are less than previously predicted by about a factor of 1 6 within 100 km because of a slightly lower average stress parameter 140 bars versus 180 bars and a steeper near source attenuation at frequencies less than 5 hz the predicted ground motions from the new equations are generally within 25 of those predicted by atkinson and boore 1995 the prediction equations agree well with available ena ground motion data as evidenced by near zero average residuals within a factor of 1 2 for all frequencies and the lack of any significant residual trends with distance however there is a tendency to positive residuals for moderate events at high frequencies in the distance range from 30 to 100 km by as much as a factor of 2 this indicates epistemic uncertainty in the prediction model the positive residuals for moderate events at 100 km could be eliminated by an increased stress parameter at the cost of producing negative residuals in other magnitude distance ranges adjustment factors to the equations are provided that may be used to model this effect

seismic displacement of gently sloping coastal and marine sediment under multidirectional earthquake loading abstract gentle sediment laden slopes are typical of the onshore coastal zone and offshore continental shelf and slope coastal sediment are commonly young weakly consolidated materials that are well stratified have low strength and can mobilize shear displacements at low levels of stress seismically driven plastic displacements of these sediment pose a hazard to coastal cities buried onshore utilities and offshore infrastructure like harbor protection and outfalls one dimensional rigid downslope directed newmark sliding block analyses have been used to predict earthquake deformations generally on steeper slopes that are modeled as frictional materials this study probes the effect of multidirectional earthquake motions on inertial displacements of gently sloping ground of the coastal and offshore condition where soft compliant soil is expected toward that objective this investigation seeks to understand the effect on newmark type displacements of 1 multidirectional earthquake shaking and 2 soil compliance in order to model multidirectional effects the earthquake motions are rotated into the local slope strike and dip components on gently sloping ground including the strike component of motion always results in a larger and more accurate shear stress vector strike motions are found to contribute to downslope deformations on any declivity compliant response of the soil mass also influences the plastic displacements the magnitude of seismic displacements can be estimated with a simplified model using only the estimated soil yield acceleration ky and the peak ground velocity vmax of the earthquake motions compliance effects can be effectively mapped using the concept of plastic displacement response spectra pdrs

ground motion amplitudes for earthquakes in puerto rico we explore ground motion amplitudes for earthquakes in puerto rico using the referenced empirical approach the technique is based on the use of residual analysis to model discrepancies between ground motion observations for puerto rico and a reference ground motion prediction equation gmpe the refer ence gmpe is that of boore and atkinson 2008 for shallow crustal earthquakes in active tectonic regions as modified by atkinson and boore 2011 to improve the fit for small to moderate events amplitudes are examined for both shallow depth 34 km and deep 35 200 km earthquakes in puerto rico overall we conclude that ground motions in puerto rico are consistent in attenuation rates with those in other active regions for shallow events amplitude levels appear to be lower than those predicted by boore and atkinson 2008 but the discrepancy is magnitude dependent decreasing to a near zero bias near m 6 we thus postulate that amplitude levels may be considered equivalent for the magnitude distance range of engineering interest allowing gmpes for other active regions to be used for puerto rico furthermore deeper events have amplitudes that also appear consistent with typical gmpes for shallow events if the greater distance of the events due to their depth is considered

a preliminary probabilistic seismic hazard assessment in terms of arias intensity in southeastern spain financiado por el grupo de investigacion peligrosidad sismica y microzonificacion de la junta de andalucia rnm 0217 y por el proyecto de la cicyt ries ctidib 2002 177

the sedimentary record of pelagic biogeography abstract sedimentary remains of fossilizable marine organisms chiefly microplanktonic ones coccolithophorids silicoflagellates diatoms dinoflagellates radiolarians foraminifers have long been used for biogeographic surveys usually with the aim of unravelling paleoenvironmental settings utilization of bottom deposits rather than plankton samples has some advantages for this purpose thanatocoenoses require smaller sample sizes materials are more readily available and they eliminate the small time scale variability which obscures long term trends on the other hand the sedimentary imprint of planktonic distributional patterns is often severely distorted by fragmentation and dissolution of the biogenic remains reworking of sediments winnowing and lateral advection of shells especially toward lower latitudes seasonally and interannually variable output rates and the integration of vertically heterogeneous assemblages the biases derived from these processes are reviewed and the need for more information on selective dissolution vertical distribution patterns and planktonic reproduction and output rates is stressed given the assumptions used in paleoenvironmental studies distributional information drawn from sediment samples is less prone to yielding biased information when applied to these surveys than to bio or paleobiogeographic investigations albeit the former can also be significantly affected as a result of changes in the traits that govern the formation of biogenic sediments

applicability of the nga west2 site effects model for central and eastern north america abstract we examine the applicability of the next generation attenuation west2 nga west2 site effects model seyhan and stewart 2014 which is a v s 30 based time averaged shear wave velocity in the upper 30 m model to sites in central and eastern north america cena using the nga east ground motion database we determine residual site terms by comparing the observed cena ground motion amplitudes adjusted to b c site condition v s 30 760 m s using the western site effects model to the corresponding predicted amplitudes of a cena ground motion prediction equation for b c site condition yenier and atkinson 2015 the cena prediction model used the same western site model to level the database before model development thus residual trends reveal inadequacies of the western site effects model when applied to cena ground motions plotting the residual site terms versus their corresponding site fundamental frequencies f peak reveals significant f peak dependent trends at all frequencies average residual site terms for cena sites after the western site amplifications have been removed can be as large as 0 45 in log10 units 2 8 in nonlog units around f f peak correlating the site terms with western site effects predictions reveals that at f v s 30 in a manner that is similar to the way they behave in the nga west2 database however at higher frequencies the correlation of site amplification with v s 30 decreases markedly in cena in contrast the horizontal to vertical h v component spectral ratio as obtained from the nga east ground motion data is a good predictor of the observed f peak dependent site terms suggesting that h v spectral ratio is a more reliable predictor of site amplification for the recording stations of the nga east database the results of this study demonstrate the importance of a well calibrated regional site effects model for cena and the importance of f peak as a site indicator

regional arias intensity attenuation relationship for taiwan considering vs30 the arias intensity is a measure of earthquake intensity arrived at through the integration of a square of the acceleration time history it has been demonstrated to be an effective predictor of earthquake damage potential in relation to short period structures liquefaction and seismic slope stability and has begun to be considered as a ground motion measure suitable for use in probabilistic seismic hazard analysis psha as well as earthquake loss estimation a new empirical arias intensity attenuation relationship for shallow crustal earthquakes is developed where both fault type and a continuous site variable vs30 are considered the relationship is based on a large number of strong motion records 6570 from a wide range of earth quake magnitudes 3 9 7 6 from the taiwan strong motion instrument program tsmip network its functional form is modified from that of travasarou et al 2003 which is derived from a point source model and the coefficients are determined through nonlinear regression analyses using a mixed effects model the results show that the incorporation of vs30 can significantly reduce regression error the arias intensity value predicted in the present study is generally similar to that obtained by travasarou et al 2003 but is different in detail being more suitable for usage in psha for a tectonically young orogenic belt like that in taiwan or new zealand

seismic demand of the liquefaction potential with equivalent number of cycles for probabilistic seismic hazard analysis abstractequivalent number of cycles ncyc is a significant factor in assessing liquefaction potential during earthquakes however the effects of ncyc are considered a deterministic value by using a magnitude scaling factor and the uncertainties of these effects have not been included in the current design practice this paper calculates ncyc within the soil mass by deconvolution analysis as a function of the period of soil layer from the ground surface ts and the soil property b using a wide range of acceleration time histories the predictive model of ncyc is developed as variable dependent on earthquake magnitude peak ground acceleration pga and ratio of spectral acceleration ts and b then the ncyc model is combined with the ground motion prediction equation of pga and the prediction equation of seismic shear stress reduction coefficient rd to obtain the prediction equation of the seismic demand of the liquefaction potential k1cyc the standard deviation of k1cyc is also modeled on the

the biological record of the ice age ocean faunal census data on zooplankton microfossils in surface sediment samples are treated by q mode factor analysis and are used to describe the global distributions of five faunal provinces the polar subpolar transitional subtropical and eastern and western tropical provinces the same assemblages factors are used to describe and to map equivalent faunal provinces in the ice age ocean 18 000 b p climap 1976 1981 although based on individual studies in each ocean basin the compilation of these data on different faunal groups allows a clear comparison of water mass distributions in the modern and ice age oceans this comparison shows an expansion of the polar province an equatorward shift and compression of the subpolar and transitional subtropical provinces and an extension of the subpolar province equatorward in eastern boundary currents for the ice age interval the total area of dominance for the tropical and subpolar assemblages remained approximately constant comparison of census data between surface sediment and 18 000 b p samples shows that the greatest faunal change occurred near the subpolar regions where water mass boundaries shifted equatorward and in areas of expanded upwelling and divergence primarily eastern boundary currents and eastern equatorial areas in contrast little faunal change occurred either in the polar regions or within the central subtropical gyres

towards a high resolution global deep sea chronology for the last 750 000 years abstract variations in the ratio of 18 o 16 o as measured in shells of marine calcareous microfossils are primarily dominated by changes in global ice volume hence these variations provide a set of global time lines in deep sea sediments it is likely that the timing of major changes in oxygen isotope values is strongly influenced if not controlled by variations in the geometry of the earth s orbit since the variation of orbital parameters can be accurately calculated the opportunity exists for transforming this orbital chronology into a geological chronology through careful correlation of oxygen isotope records in a set of deep sea cores from the sub antarctic south atlantic and equatorial pacific we have assembled a composite isotopic section spanning the last 750 000 years with an average sedimentation rate of 2 3 cm 1000 years a new chronology for this time period was developed by adjusting the ages of the oxygen isotope stage boundaries in this composite section so as to extend the consistent phase relationships that exist between variations in oxygen isotope ratios and changes in obliquity and precession during the last 300 000 years to the entire 750 000 year record previously identified difficulties in phase locking precession with the filtered isotopic signal between 365 000 and 465 000 years b p have been resolved with the recognition that precessional variations have an average period of 19 000 years and not 23 000 years during this interval since this new age model yields the best match between variations in obliquity and precession and their corresponding frequency components in the oxygen isotope record we believe that it presents the most accurate chronology yet developed for deep sea sediments with this new age model providing the time control power spectral analyses of south atlantic and sub antarctic chemical and biotic indices show that there is a strong tendency for variance to be concentrated at frequencies corresponding to periods of 100 000 41 000 and 23 000 years

ground motion prediction equations for hawaii from a referenced empirical approach ground motion prediction equations gmpes for hawaii are developed using the referenced empirical approach the technique is based on the use of residual analysis that models discrepancies between ground motion observations for hawaii and a reference gmpe in this case the gmpe of boore and atkinson 2008 for shallow crustal earthquakes in active tectonic regions the referenced empirical approach provides gmpes for hawaii that are in agreement with regional ground motion observations while being constrained to follow the overall scaling behavior of ground motion that is observed in better instrumented regions gmpes are developed for both shallow depth 20 km and deep 35 to 40 km earthquakes in hawaii

settlement sliding and liquefaction remediation of layered soil a series of highly instrumented large scale centrifuge models have been tested to investigate the extent of remediation required to control settlement and lateral sliding of soil deposits at a hypothetical bridge site the baseline model represents a prototype with a 9 m thick layer of fine sand having a relative density dr of 50 the sand layer is overlain by clay floodplains with a free face at a river channel one nearly level floodplain surface supports a bridge abutment the other floodplain has a 9 slope toward the river in different models different amounts of the 50 relative density sand was densified to dr 80 full depth improvement reduced settlements and lateral sliding of the sand by about a factor of 3 due to the effects at the clay sand interface lateral sliding of the surficial clay deposit was not controlled by densification of the sand tests in which the width of the densified zone was only about 75 of the thickness of the loose sand indicated that relatively narrow zones o

pore pressure and dissipated energy in earthquakes field verification the possibility of a correlation between dynamic pore pressure increase p and dissipated energy density d in soils subjected to earthquake shaking has been the subject of speculation for nearly 20 years while cyclic loading tests have tended to confirm the d p hypothesis in the laboratory no field confirmation has been given in this paper compelling evidence is presented to support the d p model from two real earthquakes downhole acceleration records from two earthquakes are analyzed to obtain approximate histories of shear stress shear strain and dissipated energy over a range of depths the measured data were obtained from the lotung downhole array in taiwan and from the sunamachi downhole array near tokyo both of these arrays also contain pore pressure measurement devices and records of pore pressure increase during the earthquakes are available time histories of measured pore pressure will be directly compared with calculated values based on the d p hypothesis the results of this study suggest dissipated energy density may be remarkably well correlated with pore pressure increase in field situations

palaeontological and facial features of the upper jurassic hochstegen marble tauern window eastern alps micropalaeontological microscopic and mineralogical investigations of the ductily deformed and greenschist facies metamorphic hochstegen marble in the tauern window shed new light on its stratigraphy and fades new radiolarian and sponge spicule discoveries have been made in cherty limestone marbles they confirm previous age assignments and permit for the first time a more exact micropalaeontological age determination of early tithonian for the upper parts of the marble forty morphotypes of radiolarians could be distinguished in one sample a fisher diversity index of 6 is reached indicating deeper marine conditions the spicule fauna is also diverse and shows affinity to the s german malm in respect to all the data it can be presumed that carbonate sedimentation of the hochstegen marble took place in a deeper marine environment at the southern margin of the european continent helvetic realm during the whole late jurassic

a single force model for the 1975 kalapana hawaii earthquake a single force mechanism is investigated as the source of long period seismic radiation from the 1975 kalapana hawaii earthquake m s 7 1 the observed love wave radiation pattern determined from the spectra of world wide standard seismograph network and high gain long period records at 100 s is two lobed with azimuth consistent with a near horizontal single force acting opposite strike 330 to the observed displacement direction of the earthquake this pattern is inconsistent with the expected double couple pattern assuming a form of the force time history of a one cycle sinusoid the total duration of the event estimated from rayleigh waves at two international deployment of accelerometers stations is approximately 180 s the peak amplitude f o of the time function is 1 10 15 n from amplitudes of love and rayleigh waves the interpretation is that the bulk of the seismic radiation was produced by large scale slumping of a large area of the south flank of kilauea volcano the single force is a crude representation of the effect on the earth of the motion of a partially decoupled large slide mass using the mass estimated from the tsunami generation area 10 15 10 16 kg the peak acceleration of the slide block 0 1 1 m s 2 inferred from the seismic force is comparable with the acceleration due to gravity on a gently inclined plane the slump model for the kalapana earthquake is also more qualitatively consistent with the large horizontal deformation 8 m on land and tsunami associated with the earthquake which are difficult to explain with the conventional double couple source model the single force source has been used previously to model the long period seismic waves from the landslide accompanying the eruption of mount st helens volcano and may explain other anomalous seismic events as being due to massive slumping of sediments or unconsolidated material and not to elastic dislocation

reconnaissance of two liquefaction sites using small unmanned aerial vehicles and structure from motion computer vision following the april 1 2014 chile earthquake abstractsmall unmanned aerial vehicles suavs were used to reconnoiter image and model the effects of soil liquefaction at two separate sites following the m8 2 and m7 6 earthquakes near iquique

effects of seismicity models and new ground motion prediction equations on seismic hazard assessment for four canadian cities seismicityratesandground motionpredictionequations gmpes arethe key uncertainties in probabilistic seismic hazard analysis psha we explore the impact of new findings and knowledge from seismological and ground motion studies on seismic hazard assessment for eastern and western canada updated information includes the reevaluation of seismicity rates and their interpretation in terms of seismic source zones and the use of new gmpes we refer to our model as an interim updated seismic hazard model as it does not treat all uncertainties comprehensively rather we address the impact of key uncertainties based on our updated interim seismic hazard model uniform hazard spectra uhs at four major cities across canada are obtained and compared with uhs in the current seismic hazard maps of canada 2005 2010 whicharebasedona1995seismichazardmodeldevelopedbythegeologicalsurveyof canada sensitivity analysis highlights the significant impact of seismicity smoothing in low to moderate seismic regions eastern canada while gmpes are important for all regions moreover our interim updated seismic hazard model can readily produce seismic hazard curves as well as seismic hazard deaggregation results for various site conditionsandformultipleprobabilitylevels thiscapabilityisessentialforcarryingout advanced earthquake engineering analyses

comparison of source scaling relations of eastern and western north american earthquakes source scaling relations have been obtained for earthquakes in eastern north america and other continental interiors and compared with a relation obtained for earthquakes in western north america the scaling relation for eastern north american earthquakes was constructed from measurements of seismic moment and source duration obtained by the waveform modeling of seismic body waves the events used include nine events of m blg magnitude 4 7 to 5 8 that occurred after 1960 and four earlier events with magnitudes between 5 5 and 6 6 the scaling relation for events in other continental interiors was used for comparative purposes and to provide constraints for large magnitudes detailed analysis of the uncertainties in the scaling relations has allowed the resolution of two important issues concerning the source scaling of earthquakes in eastern north america first the source characteristics of earthquakes in eastern north america and other continental interiors are consistent with constant stress drop scaling and are inconsistent with nonconstant scaling models such as that of nuttli 1983 second the stress drops of earthquakes in eastern north america and other continental interiors are not significantly different from those of earthquakes in western north america and have median values of approximately 100 bars the source parameters of earthquakes in eastern north america are consistent with a single constant stress drop scaling relation whereas the source parameters of earthquakes in western north america are much more variable and show significant departures from an average scaling relation in which stress drop decreases slightly with seismic moment

radiolarian assemblages in surface sediments along longitude 175 e in the pacific ocean abstract this study of 24 surface sediment samples along longitude 175 e between latitudes 48 n and 14 s in the western pacific ocean documents the relationship between the modern distribution of radiolarian assemblages and present oceanographic conditions ninety two species were classified into eight clusters by using r mode cluster analysis q mode cluster analysis was used to distinguish five geographical zones which were interpreted to represent the tropical southern subtropical northern subtropical transitional and subarctic climatic zones species richness diversity and equitability are highest in the tropical and transitional zones we attempted to formulate new regression equations considering ecological information on the vertical distribution of radiolarian species transfer functions were derived from regression analysis of radiolarian assemblages to observed sea surface temperature sst values the transfer functions have a standard error of 1 16 c in the estimate of winter sst 0 81 c in that of summer sst

polycystine radiolarians in surface sediments in the arctic ocean basins and marginal seas abstract the polycystine radiolarian faunas in the arctic ocean including the adjacent arctic seas have been studied in more than 377 surface samples the deep basins in the arctic ocean have revealed 31 polycystine radiolarian species 11 spumellarians and 20 nassellarians the polycystine radiolarian fauna in the southern norwegian sea was introduced from the north atlantic ocean ca 13 400 yr bp the shallow low arctic marginal sea sediments iceland barents and chukchi seas have a strong dominance of cannobotryidae 79 77 and 74 respectively while the deep arctic ocean basins nansen amundsen and makarov basins have a dominance of actinommidae 90 70 and 75 respectively the arctic polycystine radiolarian faunas have a strong affinity with the norwegian sea fauna which supplies the arctic ocean with faunal elements that can live thrive and reproduce there in the chukchi sea the pacific faunal influence is obvious 41 species but none of the pacific species are found in any abundance in the amerasian basin no radiolarian species was found to be endemic to the arctic ocean except for a morphotype of actinomma l leptoderma with a round inner sphere this species is a possible endemic candidate for the arctic ocean eight species are to be found in all of the central arctic basins and can therefore be referred to as circumpolar species actinomma leptoderma leptoderma a l leptoderma with round middle sphere a l longispina a boreale spongotrochus glacialis pseudodictyophimus platycephalus cycladophora davisiana and tholospyris gephyristes while amphimelissa setosa probably is the only true arctic radiolarian species

investigation of cyclic liquefaction with discrete element simulations abstracta discrete element method dem assembly of virtual particles is calibrated to approximate the behavior of a natural sand in undrained loading the particles are octahedral bumpy clusters of spheres that are compacted into assemblies of different densities the contact model is a jager generalization of the hertz contact which yields a small strain shear modulus that is proportional to the square root of confining stress simulations made of triaxial extension and compression loading conditions and of simple shear produce behaviors that are similar to sand undrained cyclic shearing simulations are performed with nonuniform amplitudes of shearing pulses and with 24 irregular seismic shearing sequences a methodology is proposed for quantifying the severities of such irregular shearing records allowing the 24 sequences to be ranked in severity the relative severities of the 24 seismic sequences show an anomalous dependence on sampling density four scalar measures are proposed for predicting th

intra event spatial correlations for cumulative absolute velocity arias intensity and spectral accelerations based on regional site conditions abstract spatial correlations of ground motion intensity measures ims are essential for seismic analysis of spatially distributed systems in this paper geostatistical analysis is conducted to calculate the spatial correlations for cumulative absolute velocity cav arias intensity ia and spectral accelerations sa using a total number of more than 1500 earthquake records from nine recent earthquakes occurred in taiwan california and japan the results indicate that the spatial correlations for these ims are closely related to the regional site conditions and they can be predicted based on the spatial correlations of shear wave velocity in the top 30 m v s 30 in general an im recorded from a relatively homogeneous regional site condition tends to have a larger spatial correlation range than that from a heterogeneous site condition due to their intrinsic similarity to represent the integration of acceleration time histories cav and ia have similar spatial correlation coefficients besides the range of spatial correlation of sa generally increases as the spectral period increases simple predictive equations are proposed in this study to quantify the spatial correlations of cav ia and sa based on regional site conditions methods for data correction are also proposed to eliminate artificial correlations due to biased distance scaling and v s 30 estimation in the database finally monte carlo method is used to generate spatially distributed ims the results demonstrate that the annual frequency of exceedance curves for spatially distributed ims differ significantly if different ranges of spatial correlations are used

erratum for shear wave velocity based probabilistic and deterministic assessment of seismic soil liquefaction potential by r kayen r e s moss e m thompson r b seed k o cetin a der kiureghian y tanaka and k tokimatsu