new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

evidence for surface faulting events along the paganica fault prior to the 6 april 2009 l aquila earthquake central italy 1 we performed paleoseismological investigations at four sites across the normal paganica fault pf source of the 2009 mw 6 3 l aquila earthquake with the goal of reconstructing the rupture history and of contributing to the evaluation of the maximum event expected along the pf we recognized five distinct surface faulting earthquakes including the 2009 in the trenches the age of the penultimate event is consistent with the 1461 earthquake the third event back occurred around 1000 ad the two oldest events have larger uncertainties and occurred in the interval 760 bc 670 ad and 2900 760 bc respectively the along strike vertical displacement for each paleoevent has a limited variability consistently with the fairly homogeneous slip observed in 2009 along the northern part of the rupture conversely the throws change between distinct events and range between 0 15 m in 2009 maximum estimate and close to 0 4 lower bound estimate in earlier events these paleorecords and the high fault escarpments imply that earthquakes larger than 2009 occurred on the pf with implications for the level of hazard recurrence intervals also reflect a change with time the average interval before 1000 ad is longer compared to that after this date two events occurred in the 2000 4000 years preceding 1000 ad while three events occurred since 1000 ad the age uncertainties affecting the interpreted events prevent the evaluation of a unique value for interevent interval the older events appear closely spaced in time or far apart depending on the upper or lower boundary of the age interval we tentatively assign an average interevent time of 500 years for the three youngest events whereas the time elapsed between the previous ones could be larger in the order of 1000 2000 years we calculate a late pleistocene dip slip rate for the pf of 0 2 0 4 mm yr consistent with 0 25 0 5 mm yr for the early pleistocene using age and throw of individual events we calculate a similar late holocene average dip slip rate of 0 3 0 4 mm yr this suggests that the portion of the pf where the 2009 continuous surface faulting occurred has fairly a constant average slip release since late pleistocene finally we discuss different rupture scenarios and alternative models of occurrence compatible with our data and their variability

imaging the source region of the 2004 mid niigata prefecture earthquake and the evolution of a seismogenic thrust related fold 1 the velocity structure and accurate aftershock distributions of the 2004 mid niigata prefecture earthquake are elucidated by inverting the arrival times from 716 aftershocks using double difference tomography fourteen temporal seismic stations were immediately deployed in and around the source region within 46 h of the occurrence of mainshock the seismic velocities in a hanging wall are lower than those in a footwall and the velocity contrast extends to a depth of approximately 10 km the aftershocks associated with the mainshock are distributed around the clear boundary between the low and high velocity structures it is interpreted that the mainshock fault plane of the mid niigata prefecture earthquake was reactivated as a reverse fault since the crustal shortening initiated at 3 5 ma crustal stretching or shortening along the japan coastline has created complex structures such as low velocity zones which can potentially control the seismic activities around the source region

reply to comment on near surface location geometry and velocities of the santa monica fault zone los angeles california by r d catchings g gandhok m r goldman d okaya m j rymer and g w bawden by t l pratt and j f dolan in a comment on our 2008 paper catchings gandhok et al 2008 on the santa monica fault in los angeles california pratt and dolan 2010 herein referred to as p d cite numerous objections to our work inferring that our study is flawed however as shown in our reply their objections contradict their own published works published works of others and proven seismic methodologies rather than responding to each repeated invalid objection we address their objections by topic in the subsequent sections in catchings gandhok et al 2008 we presented high resolution seismic reflection images that showed two near surface faults in the upper 50 m beneath the grounds of the wadsworth veterans administration hospital wvah although p d suggest we effectively duplicated their seismic acquisition our survey was not a duplication of their efforts rather we conducted a seismic imaging survey over a similar profile as pratt et al 1998 but used a different data acquisition system and different data processing methods to evaluate methods of seismically imaging blind faults in the wake of the 17 january 1994 m 6 7 northridge earthquake we used an acquisition method that provides both tomographic seismic velocities and reflection images our combined data approach allowed for shallower imaging 2 5 m minimum than the 20 m minimum of pratt et al 1998 clearer images of the fault zone and more accurate depth determinations rather than time images in processing the reflection images we used prestack depth migration which is generally accepted as the only proper imaging method for imaging subsurface structures with strong lateral velocity variations versteeg 1993 a condition shown to exist at the wvah site we correlated our reflection images with refraction tomography images borehole lithology and velocity data interferometric synthetic aperture radar images and changes in groundwater depths except for some minor differences our seismic reflection images coincide with previously published seismic reflection

rupture processes of the 2004 chuetsu mid niigata prefecture earthquake japan a series of events in a complex fault system 1 we relocated the hypocenters of the 2004 chuetsu earthquake sequence niigata japan using the double difference method the distribution of aftershocks reveals a complex fault system consisting of five different fault planes inversions of strong motion records for the five major events within the sequence indicate that the mainshock mw 6 6 and the largest aftershock mw 6 3 occurred on parallel wnw dipping fault planes the zones of large slip asperities of these two events are located near the hypocenters in contrast the three other large earthquakes mw 5 9 5 7 and 5 9 occurred on east dipping fault planes oriented perpendicular to the fault plane of the mainshock we used slip distributions deduced from waveform inversions to estimate the coulomb failure stress changes that occurred immediately prior to each event cff values were positive at the hypocenters and within the asperities of the major aftershocks these results suggest that stress changes resulting from individual earthquakes led directly to the occurrence of subsequent earthquakes within the complex fault system

paleoseismological evidence for non characteristic behavior of surface rupture associated with the 2004 mid niigata prefecture earthquake central japan abstract the 2004 mid niigata prefecture earthquake sequence mainshock magnitude mjma 6 8 which occurred in an active fold and thrust belt in northern central japan generated a small thrust surface rupture

introduction to special section paleoseismology a proverb of confucius states study the past if you would divine the future if we could learn about the past history of earthquakes on a specific fault then we could serve society well by better forecasting the future earthquake behavior of that fault for most of the world the period of historical records is short about 200 years in california and less than that in new zealand oregon and other parts of the world and even where the historical record is thousands of years long such as in north central china or the eastern mediterranean region it is commonly difficult to correlate a major historical earthquake with a specific active fault even if this correlation could be made without ambiguity the recurrence intervals for many faults are longer than even a historical record of several thousand years for these reasons the history of large earthquakes on faults must for the most part be learned from the geological record

late holocene activity of the dead sea transform revealed in 3d palaeoseismic trenches on the jordan gorge segment three dimensional excavations of buried stream channels that have been displaced by the jordan fault the primary strand of the dead sea fault zone in northern israel demonstrate that late holocene slip has been primarily strike slip at a minimum rate of 3 mm yr the palaeoseismic study was carried out in the bet zayda valley the delta of the jordan river at the north shore of the sea of galilee the site was chosen where a north striking scarp with up to 1 m vertical expression crosses the flat valley one group of trench excavations was located where a small stream crosses the scarp the active stream which is incised into the scarp is not offset by the fault however we found two palaeo channels about 2 m below the surface offset sinistrally 2 7f0 2 m by the fault and two younger nested channels offset 0 5f0 05 m based on radiocarbon dates we attribute the last 0 5 m rupture to the earthquake of october 30 1759 the older offset of 2 2 m most probably occurred in the earthquakes of may 20 1202 these two events correlate with the findings at ateret about 12 km north of bet zayda where the 1202 earthquake produced 1 6 m of lateral displacement in e w striking defence walls of a crusader castle and an ottoman mosque was offset 0 5 m in the earthquake of 1759 in the second group of trenches some 60 m farther south we found another offset channel its northern margin is displaced 15 m sinistrally whereas the southern margin shows only 9 m of sinistral offset the dip slip component is 1 2 m west side down the different amounts of margin offset can be explained by erosion of the southern margin during the first 6 m of displacement additional slip of 9 m accrued after the stream had been abandoned and buried by a 2 mthick lacustrine clay layers radiocarbon dates on organic residue provide the age control which indicates that the 15 m of slip has accrued over the past 5 kyr yielding a short term slip rate of 3 mm yr for the late holocene it is possible that our study

variability of displacement at a point implications for earthquake size distribution and rupture hazard on faults abstract to investigate the nature of earthquake magnitude distributions on faults we compare the interevent variability of surface displacement at a point on a fault from a composite global data set of paleoseismic observations with the variability expected from two prevailing magnitude frequency distributions the truncated exponential model and the characteristic earthquake model we use forward modeling to predict the coefficient of variation cv for the alternative earthquake distributions incorporating factors that would effect observations of displacement at a site the characteristic earthquake model with a characteristic magnitude range of 0 25 produces cv values consistent with the data cv 0 5 only if the variability for a given earthquake magnitude is small this condition implies that rupture patterns on a fault are stable in keeping with the concept behind the model this constraint also bears upon fault rupture hazard analysis which for lack of point specific information has used global scaling relations to infer variability in average displacement for a given size earthquake exponential distributions of earthquakes from m 5 to the maximum magnitude give rise to cv values that are significantly larger than the empirical constraint a version of the model truncated at m 7 however yields values consistent with a larger cv 0 6 determined for small displacement sites although this result allows for a difference in the magnitude distribution of smaller surface rupturing earthquakes it may reflect in part less stability in the displacement profile of smaller ruptures and or the tails of larger ruptures online material global surface displacement data and identified sources of uncertainty

retrodeformation analysis of the quaternary fault in the southeastern korean peninsula abstract the suryum fault f1 with subsidiary branches f2 3 varies in strike from n40 e to n14 e and in dip from

do buried rupture earthquakes trigger less landslides than surface rupture earthquakes for reverse faults abstract gorum et al 2013 geomorphology 184 127 138 carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 mw 7 0 haiti earthquake they revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography they also suggested that blind rupture earthquakes trigger fewer landslides than surface rupture earthquakes on thrust reverse faults although a few lines of evidence indicate that buried rupture earthquakes might trigger fewer landslides than surface rupture earthquakes on reverse faults more careful comparisons and analyses indicate that it is not always true instead some cases show that a buried rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area whereas surface rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area

paleoseismic evidence of characteristic slip on the western segment of the north anatolian fault turkey we have conducted a paleoseismic investigation of serial fault rupture at one site along the 110 km rupture of the north anatolian fault that produced the mw 7 4 earthquake of 17 august 1999 the benefit of using a recent rupture to compare serial ruptures lies in the fact that the location magnitude and slip vector of the most recent event are all very well documented we wished to determine whether or not the previous few ruptures of the fault were similar to the recent one we chose a site at a step over between two major strike slip traces where the principal fault is a normal fault our two excavations across the 1999 rupture reveal fluvial sands and gravels with two colluvial wedges related to previous earthquakes each wedge is about 0 8 m thick considering the processes of collapse and subsequent diffusion that are responsible for the formation of a colluvial wedge we suggest that the two paleoscarps were similar in height to the 1999 scarp this similarity supports the concept of characteristic slip at least for this location along the fault accelerator mass spectrometry ams radiocarbon dates of 16 charcoal samples are consistent with the interpretation that these two paleoscarps formed during large historical events in 1509 and 1719 if this is correct the most recent three ruptures at the site have occurred at 210 and 280 year intervals

rupture terminations and size of segment boundaries from historical earthquake ruptures in the basin and range province abstract the fault segmentation method is commonly used to estimate the potential earthquake size segment boundaries play an important role in arresting earthquake ruptures from event to event in the basin and range province earthquake rupture terminations are commonly associated with structural discontinuities but not all structural discontinuities have the capability to terminate an earthquake rupture the size of structural discontinuities with respect to the rupture length and displacement may play an important role in controlling rupture termination studies of the geometric pattern of seven well documented historical earthquake ruptures in the basin and range province reveal three important relationships between rupture termination and the size of structural discontinuities firstly terminations of normal faulting earthquakes are often associated with structural discontinuities at least for the five historical ruptures studied in this paper secondly the sizes of structural discontinuities at the end of earthquake rupture zones are generally the largest among the structural discontinuities within the rupture zone thirdly there appears to be a trend that larger earthquake ruptures are stopped by larger structural discontinuities the size of structural discontinuities that stopped the earthquake seems to scale with the length and displacement of earthquake surface rupture

uncharacteristic earthquakes on the san andreas fault one model of earthquake recurrence holds that large quakes exhibit regular or characteristic rupture patterns combined with a simple picture of how elastic strain accumulates in the faults this implies that characteristic earthquakes occur at regular intervals in her perspective grant proposes that recent data from study sites along the san andreas fault are difficult to understand with this model the earthquake activity is more irregular and more clustered than the model would suggest

a new method for dating tree rings in trees with faint indeterminate ring boundaries using the itrax core scanner abstract eastern australia is known to experience multi decadal periods of flood and drought subtropical southeast queensland is one region where these devastating extreme events occur regularly yet a full understanding of their frequency and magnitude cannot be determined from the short duration 100 years proxy rainfall information but locating suitable forest stands is difficult due to extensive land clearing by european settlers another factor deterring the use of trees as proxy data sources is that longer lived species frequently contain anomalous rings particularly faint rings hindering their use for paleoclimate study here we present a method which overcomes the problems of identifying faint ring boundaries in trees by using x radiographs and density patterns developed on the itrax core scanner we analysed 39 tree cores from 20 trees at a site in d aguilar national park located just north of brisbane city in queensland australia each core had a 2 mm lath cut perpendicular to its rings which was then passed through an itrax core scanner the tree ring boundaries were identified on the image by both the visual features in the radiograph and the change in density observed between rings from this information we developed a tree ring chronology the chronology was checked using bomb pulse radiocarbon dating on five trees to confirm the annual nature of the rings and to correct dating errors in the chronology due to false rings which are common in this species climate response function analysis showed austral annual rainfall june may was the dominant environmental variable driving tree growth finally a 69 year statistically significant reconstruction of brisbane precipitation was produced showing that this non destructive itrax ring identification technique together with age validation by bomb pulse radiocarbon dating is useful for dendroclimatological studies of trees with faint ring boundaries

fault behavior and characteristic earthquakes examples from the wasatch and san andreas fault zones paleoseismological data for the wasatch and san andreas fault zones have led to the formulation of the characteristic earthquake model which postulates that individual faults and fault segments tend to generate essentially same size or characteristic earthquakes having a relatively narrow range of magnitudes near the maximum analysis of scarp derived colluvium in trench exposures across the wasatch fault provides estimates of the timing and displacement associated with individual surface faulting earthquakes at all of the sites studied the displacement per event has been consistently large measured values range from 1 6 to 2 6 m and the average is about 2 m on the basis of variability in the timing of individual events as well as changes in scarp morphology and fault geometry six major segments are recognized along the wasatch fault on the basis of the most likely number of surface faulting events 18 that have occurred on segments of the wasatch fault zone during the past 8000 years an average recurrence interval of 400 666 years with a preferred average of 444 years is calculated for the entire zone geologic data on the distribution of slip associated with prehistoric earthquakes and slip rates along the south central segment of the san andreas fault suggest that the m 8 1857 earthquake is a characteristic earthquake for this segment comparisons of earthquake recurrence relationships on both the wasatch and san andreas faults based on historical seismicity data and geologic data show that a linear constant b value extrapolation of the cumulative recurrence curve from the smaller magnitudes leads to gross underestimates of the frequency of occurrence of the large or characteristic earthquakes only by assuming a low b value in the moderate magnitude range can the seismicity data on small earthquakes be reconciled with geologic data on large earthquakes the characteristic earthquake appears to be a fundamental aspect of the behavior of the wasatch and san andreas faults and may apply to many other faults as well

variation in fault behaviour in different tectonic provinces of new zealand abstract fault behaviour appears to be different in different tectonic provinces of new zealand uplifted holocene marine terraces along the east coast of the north island suggest time predictable behaviour on reverse faults of the hikurangi subduction margin major dextral faults of the strike slip fault province in central new zealand appear to show characteristic slip behaviour short normal faults in the central volcanic region show highly variable increments of displacement finally reverse faults of the central otago and northwest nelson region may have intermittently characteristic patterns of activity each of these behaviour patterns has been observed elsewhere although where there are good data to constrain the actual dates of palaeoearthquakes a uniform slip or coupled model best explains most situations temporal and spatial clustering of fault rupture and major earthquakes are increasingly being recognized it is crucial to obtain better dates and to determine the extent of individual rupture segments in order to better characterize fault behaviour non characteristic fault behaviour has serious implications for current methods of seismic hazard evaluation seismic hazard studies should utilize specific fault data in preference to assuming a particular fault behaviour model

dating past earthquakes and related sediments by thermoluminescence methods a review abstract applications of luminescence dating of geological materials have undergone extensive development and refinement since 1986 when mccalpin first attempted to date faults using thermoluminescence tl today luminescence methods offer high potential for dating paleoearthquakes and coseismic and post seismic deformation features over timescales ranging from 102 to 106 a while luminescence approaches generally do not possess the precision obtained by for example 40ar 39ar and 14c methods they offer a useful alternative approach with advantages in terms of age range and scope of material although the application of luminescence dating has in some cases been successfully described a comprehensive study outlining and defining protocols for routine luminescence methods to paleoseismology and neotectonic studies has not been forthcoming this review surveys previous attempts to apply tl techniques to paleoseismology and determination of the age of sediments associated with seismic events however while the use of tl has been a great success the wide application of tl has been hampered by the problem of daylight signal resetting

the repetition of large earthquake ruptures abstract this survey of well documented repeated fault rupture confirms that some faults have exhibited a characteristic behavior during repeated large earthquakes that is the magnitude distribution and style of slip on the fault has repeated during two or more consecutive events in two cases faults exhibit slip functions that vary little from earthquake to earthquake in one other well documented case however fault lengths contrast markedly for two consecutive ruptures but the amount of offset at individual sites was similar adjacent individual patches 10 km or more in length failed singly during one event and in tandem during the other more complex cases of repetition may also represent the failure of several distinct patches the faults of the 1992 landers earthquake provide an instructive example of such complexity together these examples suggest that large earthquakes commonly result from the failure of one or more patches each characterized by a slip function that is roughly invariant through consecutive earthquake cycles the persistence of these slip patches through two or more large earthquakes indicates that some quasi invariant physical property controls the pattern and magnitude of slip these data seem incompatible with theoretical models that produce slip distributions that are highly variable in consecutive large events