long range earthquake forecasting with every earthquake a precursor according to scale scaling relations previously derived from examples of the precursory scale increase before major earthquakes show that the precursor is a long term predictor of the time magnitude and location of the major earthquake these relations are here taken as the basis of a stochastic forecasting model in which every earthquake is regarded as a precursor the problem of identifying those earthquakes that are actually precursory is thus set aside at the cost of limiting the strength of the resulting forecast the contribution of an individual earthquake to the future distribution of hazard in time magnitude and location is on a scale determined through the scaling relations by its magnitude provision is made for a contribution to be affected by other earthquakes close in time and location e g an aftershock may be given low weight using the new zealand catalogue the model has been fitted to the forecasting of shallow earthquakes exceeding magnitude 5 75 over the period 1965 2000 it fits the data much better than a baseline poisson model with a location distribution based on proximity to the epicenters of past earthquakes further the model has been applied with unchanged parameters to the california region over the period 1975 2001 there also it performs much better than the baseline model fitted to the same region over the period 1951 1974 the likelihood ratio is 1015 in favor of the present model these results lend credence to the precursory scale increase phenomenon and show that the scaling relations are pervasive in earthquake catalogues the forecasting model provides a new baseline model against which future refinements and other proposed models can be tested it may also prove to be useful in practice its applicability to other regions has still to be established

mixture models for improved earthquake forecasting with short to medium time horizons abstract optimal mixtures of three space time magnitude earthquake likelihood models are found for forecasting earthquakes with magnitudes of 5 0 and greater in the new zealand and california catalogs with forecasting time horizons ranging from 0 to 3000 days the models are the epidemic type aftershock etas short term clustering model the every earthquake a precursor according to scale eepas medium term clustering model and the proximity to past earthquakes ppe quasi time invariant smoothed seismicity model the etas model is by far the most informative of these models for short time horizons of a few days but even with a zero time horizon an optimal mixture of the three models here called the janus model outperforms it with an information gain per earthquake igpe of about 0 1 for time horizons of 10 3000 days the janus model outperforms the most informative of its component models with igpes ranging from 0 2 to 0 5 as the time horizon lengthens beyond six months in new zealand and two years in california the eepas model becomes the most informative of the individual models and the major component of the optimal mixture changes in the janus model parameters with the forecasting time horizon reveal features of time and area scaling of precursory seismicity the results suggest that both cascades of triggering and the precursory scale increase phenomenon contribute to earthquake predictability and that these contributions are largely independent

nappes tectonics of oblique plate convergence and metamorphic evolution related to 140 million years of continuous subduction franciscan complex california this paper presents a new synthesis of franciscan complex tectonics with the emphasis on the pre san andreas fault history of these rocks field relations suggest that the franciscan is characterized by nappe structures that formed during sequential accretion at the trench the presence of these structures along with other field relations including the lack of evidence for large offset of conglomerate suites indicates that strike slip fault systems of large displacement 500 km did not cut the franciscan complex during subduction regional geology and comparisons to modern arc trench systems suggest that strike slip faulting associated with oblique subduction took place inboard east of the franciscan in the vicinity of the magmatic arc the franciscan varies along strike because individual accreted elements packets of trench sediment seamounts etc did not extend the full length of the trench different depths of underplating distribution of post metamorphic faulting and level of erosion pro

mode of strong earthquake recurrence in the central ionian islands greece possible triggering due to coulomb stress changes generated by the occurrence of previous strong shocks the spatiotemporal distribution of shallow strong m 6 3 earthquakes occurring in the area of central ionian islands is analyzed these shocks are generated on two adjacent fault segments with different strike but both segments are associated with strike slip faulting constituting the boundary between continental collision to the north and oceanic subduction to the south seismic activity is concentrated in short time intervals alternating with much longer relatively quiescent periods each active period consists of a relatively large event or series two to four of events occurring closely both in space and time this alteration was observed to happen four times since 1867 the period when complete data exist for the study area since the phenomenon is not strictly periodic and during each active period multiple events occurred i attempted to interpret the seismic behavior on the basis of possible trig gering i then investigated how changes in coulomb failure function dcff asso ciated with one or more earthquakes may trigger subsequent events both the co seismic slip due to the generation of the strong earthquakes and stress buildup associated with the two major fault segments were taken into account for the dcff calculation earthquakes can be modeled as static dislocations in elastic half space and the stress pattern has been calculated according to the geometry and slip of each of the faults that ruptured in the chain of events these calculations show that 13 out of 14 earthquakes of m 6 3 were preceded by a static stress change that encouraged failure the magnitude of the stress increases transferred from one earthquake to another ranged from 0 01 mpa 0 1 bar to over 0 1 mpa 1 bar showing that stress transfer adequately explains the occurrence pattern of these events maps of current dcff provide additional information to long term earthquake prediction areas of positive dcff have been identified at two sites in kefalonia and lefkada faults respectively where the next strong events are expected to occur a fact that will substantiate the hypothesis elaborated in this article

large pressure gap between the coastal and central franciscan belts northern and central california abstract the nature of the metamorphism of the central belt of the franciscan complex has long been debated did the whole central belt or its melange matrix undergo high p t metamorphism to solve this problem we have investigated the regional distribution of aragonite in these rocks in northern and central california we have discovered more than 300 new localities of aragonite using the staining method by friedman 1959 aragonite occurs as network veins or pods in both metagraywacke and matrix forming metashale and is invariably partially replaced by calcite on its rim thus we conclude that aragonite is stable in all parts of the franciscan central belt from the lower boundary between the coastal and central belts to the topmost part of the central belt and that both the matrix forming melange shale and exotic blocks of the central belt suffered high p t metamorphism we traced the boundary between the central and coastal belts in northern california using the staining method along the gently eastward dipping thrust plane between the underlying coastal and overlying central belts more than 2 5 kbar pressure break is obtained through the lawsonite laumontite aragonite quartz relations such an observed large pressure gap was formed during the exhumation process of the central belt of the franciscan complex

evolution of the stress field in the northern aegean sea greece summary the evolution of the stress field in the area of the northern aegean sea during the 20th century has been studied the area is dominated by dextral strike slip faulting and is characterized by frequent strong earthquakes coulomb stress changes dcff were calculated assuming that earthquakes can be modelled as static dislocations in an elastic half space and taking into account both the coseismic slip in large mi7 0 earthquakes and the slow tectonic stress build up along the major fault segments the stress change calculations were performed for strike slip faults of strike dip and rake appropriate to the large events we evaluate whether these stress changes brought a given large earthquake closer to or farther from failure it was found that each of the large events occurred in regions of increased calculated coulomb stress moreover the majority of smaller events for which reliable fault plane solutions are available were also located in areas of positive dcff by extending the calculations to 2020 and assuming that no additional large mi7 0 earthquake occurs between 1999 and 2020 possible sites of future large earthquakes are identified

phanerozoic continental accretion and the metamorphic evolution of northern and central california abstract the late paleozoic and younger tectonic fabric of california north of the transverse ranges consists of accreted exotic and parautochthonous lithic belts which extend north south and northwest southeast separated from one another by subvertical strike slip faults and gently to steeply east dipping thrust faults where recognizable folds in general verge to the west and stratigraphic tops face east a rough but systematic westward decrease in geologic age and metamorphic intensity may also be recognized exotic terranes of uncertain provenance include the central metamorphic belt of the klamath mountains and the salina sur obispo composite block of the central coast ranges pre permian sections of the eastern klamath terrane and portions of the sierran calaveras melones complex may also represent far traveled crustal entities allochthonous oceanic basement seamounts and pelagic sediments are additional transported materials widespread in most of the parautochthonous lithotectonic belts that make up much of the rest of northern and central california ophiolitic assemblages are especially abundant along the fault zones which mark boundaries between these units the parautochthonous lithotectonic belts appear to have been constructed in the vicinity of the continental margin and or an offshore arc judging from the nature and provenance of their constituent igneous and sedimentary rocks intimately associated tholeiitic calc alkaline complexes indicate that at least locally ophiolite generation occurred nearby the salinia sur obispo amalgamated terrane exhibits the effects of fragmentation and removal of crust now represented by the suture juxtaposing the two blocks other areas may have been subjected to similar truncations but relationships are not as clear far traveled terranes are characterized by ages of formation and recrystallization foreign to surrounding units the nature of the protoliths and grades of metamorphism developed within them contrast with those of juxtaposed lithotectonic belts on the other hand essentially in situ growth of many californian lithotectonic belts is suggested by a gradually decreasing age of formation and both monotonically decreasing times and grades of metamorphism proceeding towards the pacific basin some parautochthonous units as well as exotic terranes are locally bounded by discontinuous blueschist belts the latter attesting to at least episodic preservation of the effects of subduction metamorphism and offloading into the accreting continental margin phanerozoic evolution of northern and central california thus apparently consisted of a more or less in situ seaward encroachment of the continental margin relative to the craton involving occasional truncation and loss of section with a concomitant semi continuous or episodic incorporation of allochthonous seamounts oceanic crust and deep sea sediments and the less frequent arrival and juxtaposition of exotic microcontinental fragments of problematic but distant source

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

extended characterization of damage in rubble mound scour protections abstract the analysis of damage in rubble mound scour protections is crucial for the armour stability assessment former methodologies focused on the analysis of the maximum damage number this work introduces a complementary methodology to determine and characterize damage statistical distribution based on a flexible arrangement of sub areas the sub areas are overlapping and can be varied in size allowing a refined damage analysis to capture the variation of damage with changing sub area layout the methodology is coupled with a statistical evaluation of damage numbers which is enabled by the definition of a grid ratio between armour stone size and sub area size dn50 2 asub the methodology is applied to high resolution bathymetric surveys from two stability tests of large scale rip rap scour protection around a monopile foundation and combined wave and current loading results show that the methodology provides a complementary understanding of damage distribution to the maximum damage acquired from previous methodologies in addition it allows a comparison of damage characteristics between tests despite different shapes of the foundation research concludes that the size of the sub areas influences significantly the damage description characteristic measures as the maximum damage number and standard deviation become stable at a grid ratio dn50 2 asub equal to 1 4

demarcation and scaling of long term seismogenesis a space time envelope of minor seismicity related to major shallow earthquakes is identified from observations of the long term precursory scale increase phenomenon which quantifies the three stage faulting model of seismogenesis the envelope which includes the source area of the major earthquake is here demarcated for 47 earthquakes from four regions with tectonic regimes ranging from subduction to continental collision and continental transform the earthquakes range in magnitude from 5 8 to 8 2 and include the 24 most recent mainshocks of magnitude 6 4 and larger in the san andreas system of california the hellenic arc region of greece and the new zealand region together with the six most recent mainshocks of magnitude 7 4 and larger in the pacific arc region of japan also included are the destructive earthquakes that occurred at kobe japan 1995 magnitude 7 2 izmit turkey 1999 magnitude 7 4 and w tottori japan 2000 magnitude 7 3 the space a p in the space time envelope is optimised with respect to the scale increase while the time t p is the interval between the onset of the scale increase and the occurrence of the earthquake a strong correlation is found between the envelope a p t p and the magnitude of the earthquake hence the conclusion that the set of precursory earthquakes contained in the envelope is intrinsic to the seismogenic process yet a p and t p are correlated only weakly with each other suggesting that a p is affected by differences in statical conditions such as geological structure and lithology and t p by differences in dynamical conditions such as plate velocity among other scaling relations predictive regressions are found between on the one hand the magnitude level of the precursory seismicity and on the other hand both t p and the major earthquake magnitude hence the method as here applied to retrospective analysis is potentially adaptable to long range forecasting of the place time and magnitude of major earthquakes

accelerating seismicity and stress accumulation before large earthquakes the stress field that existed before a large earth quake can be calculated based on the known source parame ters of the event this stress field can be used to define a region that shows greater seismic moment rate changes prior to the event than arbitrarily shaped regions allowing us to link two previously unrelated subjects coulomb stress interactions and accelerating seismicity before large earthquakes as an example we have examined all m 6 5 earthquakes in california since 1950 while we illustrate the model using seismicity in california the technique i s general and can be applied to any tectonically active re gion we show that where sufficient knowledge of the re gional tectonics exists this method can be used to aug ment current techniques for seismic hazard estimation

evolving towards a critical point a review of accelerating seismic moment energy release prior to large and great earthquakes there is growing evidence that some proportion of large and great earthquakes are preceded by a period of accelerating seismic activity of moderate sized earthquakes these moderate earthquakes occur during the years to decades prior to the occurrence of the large or great event and over a region larger than its rupture zone the size of the region in which these moderate earthquakes occur scales with the size of the ensuing mainshock at least in continental regions a number of numerical simulation studies of faults and fault systems also exhibit similar behavior the combined observational and simulation evidence suggests that the period of increased moment release in moderate earthquakes signals the establishment of long wavelength correlations in the regional stress field the central hypothesis in the critical point model for regional seismicity is that it is only during these time periods that a region of the earth s crust is truly in or near a self organized critical soc state such that small earthquakes are capable of cascading into much larger events the occurrence of a large or great earthquake appears to dissipate a sufficient proportion of the accumulated regional strain to destroy these long wavelength stress correlations and bring the region out of a soc state continued tectonic strain accumulation and stress transfer during smaller earthquakes eventually re establishes the long wavelength stress correlations that allow for the occurrence of larger events these increases in activity occur over longer periods and larger regions than quiescence which is usually observed within the rupture zone of a coming large event the two phenomena appear to have different physical bases and are not incompatible with one another

comparative performance of time invariant long range and short range forecasting models on the earthquake catalogue of greece 1 time invariant long range and short range forecasting models were fitted to the earthquake catalogue of greece for magnitudes 4 0 and greater to optimize their ability to forecast events of magnitude 6 0 and greater in the period 1966 1980 the models considered were stationary spatially uniform and spatially varying poisson models a long range forecasting model based on the precursory scale increase phenomenon with every earthquake regarded as a precursor according to scale and epidemic type short range forecasting models with spatially uniform and spatially varying spontaneous seismicity each of the models was then applied to the catalogue for 1981 2002 and their forecasting performance was compared using the log likelihood statistic the long range forecasting model performed substantially better than the time invariant models and the short range forecasting models performed substantially better again the results show that the information value to be gained from modeling temporal and spatial variation of earthquake occurrence rate at both long and short range is much greater than can be gained from modeling spatial variation alone

in the shadow of 1857 the effect of the great ft tejon earthquake on subsequent earthquakes in southern california the great 1857 fort tejon earthquake is the largest earthquake to have hit southern california during the historic period we investigated if seismicity patterns following 1857 could be due to static stress changes generated by the 1857 earthquake when post 1857 earthquakes with unknown focal mechanisms were assigned strike slip mechanisms with strike and rake determined by the nearest active fault 13 of the 13 southern california m 5 5 earthquakes between 1857 and 1907 were encouraged by the 1857 rupture when post 1857 earthquakes in the transverse ranges with unknown focal mechanisms were assigned reverse mechanisms and all other events were assumed strike slip 11 of the 13 earthquakes were encouraged by the 1857 earthquake these results show significant correlations between static stress changes and seismicity patterns the correlation disappears around 1907 suggesting that tectonic loading began to overwhelm the effect of the 1857 earthquake early in the 20th century

metamorphic evolution of two different eclogites in the franciscan complex california u s a the eclogites in california u s a have been regarded as tectonic blocks which formed 150 160 ma ago and have been tectonically incorporated into younger rocks of the franciscan complex of 90 130 ma however in ward creek northern california two different types of eclogites were identified type i is a typical tectonic block and type ii is a possible in situ eclogite formed during the franciscan metamorphism most eclogites in the franciscan complex are type i eclogites type i eclogites in ward creek consist of garnet omphacite epidote glaucophane phengite rutile barroisite quartz and have coarse grained gneissic texture they have precursors of the epidote amphibolite facies and are overprinted in various degrees by blueschist facies retrograde metamorphism remnants of metamorphic rinds which consist of actinolite talc chlorite and formed during metasomatic interaction with serpentinizing peridotite occur at the margins of type i eclogite blocks type ii eclogites are medium grained and consist of garnet chloromelaniticclinopyroxene epidote glaucophane paragonite phengite rutile quartz petrochemical characters of type ii eclogites are similar to those of in situ eclogitic schists in the ward creek metabasite sequence epidote amphibolite f facies precursors metamorphic rinds and overprint of retrogressive blueschist facies metamorphism are not found in type ii eclogites garnets in type ii eclogites are medium grained unaltered and idioblastic and have higher spessartine contents sp14 25 whereas garnets in type i eclogites are coarse grained and chloritized and have lower spessartine contents sp2 7 the pt conditions of peak metamorphism for type ii eclogites are 380 10 11 5 kb type i eclogites follow a counter clockwise pt path from the epidote amphibolite through eclogite to blueschist facies whereas the presumable in situ type ii eclogites follow a clockwise pt path from the blueschist to eclogite facies

stress coupling between earthquakes in northwest turkey and the north aegean sea we have investigated the coulomb stress interactions of 29 earthquakes m s greater than or equal to 6 0 that have occurred in the region of northwest turkey and north aegean sea since 1912 of these events 23 may be related to earlier events and 16 are clearly related to earlier events all events after 1967 are related to previous events events in the early part of our time interval that show no correlation could be related to historical events as yet unidentified in some cases faults that have received a stress reduction from earlier events are prepared for an event by an earthquake occurring a few years before that creates a local coulomb stress rise thus regions of coulomb stress shadow can become regions where a damaging earthquake may occur the relation between smaller events and the coulomb stress distribution is less clear but may be related to poor data quality and practical limitations of our modeling technique nonetheless there are 4 times as many events per unit area in regions of enhanced stress than where stress is reduced we discuss the contemporary distribution of coulomb stress and argue that it is possible to identify the likely locations of future damaging earthquakes including identifying the most likely candidate faults

nonlinear strain buildup and the earthquake cycle on the san andreas fault two contrasting models of the earthquake deformation cycle on strike slip faults predict significant temporal declines in shear strain rate near the fault accompanied by a progressive broadening of the zone of deformation adjacent to it in the thin lithosphere model transient deformation results from flow in the asthenosphere due to stress relaxation following faulting through most or all of the lithosphere for an earth model with a thick elastic lithosphere plate thickness depth of seismic slip transient motions are due to postearthquake aseisrnic slip below the coseismic fault plane data from the san andreas fault indicate a long term temporal decrease in strain rate that persists for at least 30 years and may extend through the entire earthquake cycle observations support a cycle long rate decrease and a temporal spreading of the deformation profile only if movement cycles on the northern and southern locked sections of the fault are basically similar if so the usually lower strain rates and broader deformation zone currently observed on the southern san andreas represent a later evolutionary stage of the northern locked section where a great earthquake is a more recent occurrence although the data allow some extreme models to be discarded no sufficiently strong constraints exist to decide between the thin and thick lithosphere models regardless of the appropriate model the geodetic observations themselves indicate that strain buildup is sufficiently nonlinear to cause significant departures from recurrence estimates based on linear strain accumulation and the time predictable model

long term seismogenic process for major earthquakes in subduction zones abstract a qualitative physical process for the long term seismogenesis of major earthquakes in subduction zones is proposed on the basis of quantitative empirical evidence that swarms mainshocks and aftershocks are closely related phenomena the relations which have been identified in the comprehensive long term catalogues of new zealand and japan represent swarms as predictors of mainshocks with respect to location time and magnitude clustering of swarms and of mainshock aftershock events is allowed for with a database of 15 sequences of swarms mainshocks and aftershocks tests are being conducted with the object of refining the relations and evaluating them as a possible means of practical synoptic forecasting three sequences have culminated in major earthquakes since the tests began and the systematic study now relates a total of 36 swarms with 29 mainshock aftershock events these empirical results strengthen and quantify the connection between swarms and major earthquakes which several authors have demonstrated by means of numerical physical modelling the proposed seismogenic process includes swarms mainshocks and aftershocks as separate event stages which are related by predictability interevent conditions are specified according to the mogi criteria for the medium cracks at which fractures subsequently occur constitute nonuniformity in the mogi sense and post earthquake healing restores uniformity where the gutenberg richter relation occurs it is accepted as possible evidence of deterministic chaos and unpredictability as a corollary the process is noncyclical the principle of scaling is held to apply except when modified by large scale boundaries in the medium subduction zones and some other localities where water is abundant are indicated by the main empirical studies as favourable to the occurrence of swarms fluid overpressuring is therefore proposed as a mechanism for the self triggering of swarms and this is supported by additional examples of the predictive relations occurring in conditions of high fluid pressure including the vicinity of large man made reservoirs the process can be tested by systematic studies in other subduction regions given adequate catalogues for quantifying the algorithm it also has implications for other tectonic environments with swarms replaced by cognate more protracted seismicity precursors

subduction and accretion of the permanente terrane near san francisco california previous studies of the calera limestone permanente terrane franciscan complex of california have shown that deposition occurred at approximately 25 n paleolatitude atop an oceanic plateau or rise and that it was subsequently transported northeast and accreted to the north american continental margin in the early tertiary the permanente terrane in the study area along the pacific coast south of san francisco contains a suite of rock types present in north dipping imbricate thrust slices possibly related to the subduction and accretion of an oceanic crustal sequence geochemical studies of greenstones thought to represent fragments of the dismembered oceanic crust indicate affinities with mid ocean ridge basalts and within plate basalt these greenstones may represent fragments of the rise upon which the calera limestone was deposited metamorphic minerals in the greenstones indicate both sea floor metamorphism and locally high pressure low temperature metamorphism it is concluded tentatively that the entire permanente terrane in the study area underwent high pressure low temperature metamorphism but that temporal or geologic conditions prevented widespread recrystallization or development of blueschist facies minerals structures in the deformed rocks can be related to underthrusting beneath the continental margin and attachment to the overriding plate studies of veins indicate several stages of dewatering it is likely that dewatering was a major process in the attachment event as shown by veins associated with this phase of deformation structurally interleaved melanges and broken formation contain sedimentary rock clearly derived from a continental margin these rocks probably represent trench and trench slope facies that were underthrust with the accreting oceanic crustal sequence

evolution of the stress field in southern california and triggering of moderate size earthquakes a 200 year perspective changes in stress in southern california are modeled from 1812 to 2025 using as input 1 stress drops associated with six large 7 0 7 5 earthquakes through 1995 and 2 stress buildup associated with major faults with slip rates 3 mm yr as constrained by geodetic paleoseismic and seismic measurements evolution of stress and the triggering of moderate to large earthquakes are treated in a tensoffal rather than a scalar manner we present snapshots of the cumulative coulomb failure function acff as a function of time for faults of various strike dip and rake throughout southern california we take acff to be zero everywhere just prior to the great shock of 1812 we find that about 95 of those well located m 6 earthquakes whose mechanisms involve either strike slip or reverse faulting are consistent with the coulomb stress evolutionary model that is they occurred in areas of positive acff the interaction between slow moving faults and stresses generated by faster moving faults significantly advanced the occurrence of the 1933 long beach and 1992 landers events in their earthquake cycles coulomb stresses near major thrust faults of the western and central transverse ranges have been accumulating for a long time future great earthquakes along the san andreas fault especially if the san bernardino and coachella valley segments rupture together can trigger moderate to large earthquakes in the transverse ranges as appears to have happened in the santa barbara earthquake that occurred 13 days after the great san andreas shock of 1812 maps of current acff provide additional guides to long term earthquake prediction

correlation of static stress changes and earthquake occurrence in the north aegean region a systematic analysis is made of static coulomb stress changes and earthquake occurrence in the area of the north aegean sea greece in order to assess the prospect of using static stress changes to construct a regional earthquake likelihood model the earthquake data set comprises all events of magnitude m 5 2 which have occurred since 1964 this is compared to the evolving stress field due to constant tectonic loading and perturbations due to coseismic slip associated with major earthquakes m 6 4 over the same period the stress was resolved for sixteen fault orientation classes covering the observed focal mechanisms of all earthquakes in the region analysis using error diagrams shows that earthquake occurrence is better correlated with the constant tectonic loading component of the stress field than with the total stress field changes since 1964 and that little if any information on earthquake occurrence is lost if only the maximum of the tectonic loading over the fault orientation classes is considered moreover the information on earthquake occurrence is actually increased by taking the maximum of the evolving stress field since 1964 and of its coseismic slip component over the fault orientation classes the maximum over fault orientation classes of linear combinations of the tectonic loading and the evolving stress field is insignificantly better correlated with earthquake occurrence than the maximum of the tectonic loading by itself a composite stress change variable is constructed from ordering of the maximum tectonic loading component and the maximum coseismic slip component in order to optimize the correlation with earthquake occurrence the results indicate that it would be difficult to construct a time varying earthquake likelihood model from the evolving stress field that is more informative than a time invariant model based on the constant tectonic loading

long term seismogenesis in greece comparison of the evolving stress field and precursory scale increase approaches 1 recent strong m 6 6 earthquakes in greece are examined from the point of view of two current but disparate approaches to long term seismogenesis these are the evolving stress field esf approach in which earthquakes are considered to be triggered by accumulated stress changes from past earthquakes and tectonic loading on the major faults and the precursory scale increase approach in which a major earthquake is preceded in the long term by an increase in minor earthquake occurrences with the magnitude of the precursory earthquakes and the precursor time and area all scaling with the major earthquake magnitude the strong earthquakes are found to be consistent with both approaches and it is inferred that both approaches have a relevant role to play in the description of the long term generation process of major earthquakes a three stage faulting model proposed previously to explain the phenomenon involves a major crack which eventually fractures in the major earthquake being formed before the onset of precursory seismicity hence we examine whether esf can account for the formation of the major crack by examining the accumulated stress changes at the time of the onset of for each strong earthquake in each case the answer is in the affirmative there is enhanced stress in the vicinity of the main shock at the time of the onset the same is true for most but not all of the locations of precursory earthquakes

can deep seated gravitational slope deformations be activated by regional tectonic strain first insights from displacement measurements in caves from the eastern alps abstract tectonic elastic strain and ground deformations are documented as the most remarkable environmental phenomena occurring prior to local earthquakes in tectonically active areas the question arises if such strain would be able to trigger mass movements we discuss a directly observed fault slip and a subsequent minor activation of a deep seated gravitational slope deformation prior to the m 3 bad fischau earthquake between end of november and early december 2013 in ne austria the data originate from two faults in the emmerberg and eisenstein caves in the transition zone between the eastern alps and the vienna basin monitored in the framework of the fwf speleotect project the fault slips have been observed at the micrometer level by means of an opto mechanical 3d crack gauge tm 71 the discussed event started with the fault activation in the emmerberg cave on 25 november 2013 recorded by measurements of about 2 m shortening and 1 m sinistral parallel slip which was fully in agreement with the macroscopically documented past fault kinematics one day later the mass micro movement activated on the opposite side of the mountain ridge in the eisenstein cave and it continued on three consecutive days further the fault in the emmerberg cave experienced also a subsequent gravitational relaxation on 2 3 december 2013 when the joint opened and the southern block subsided towards the valley while the original sinistral displacement remained irreversible the process was followed by the m 3 earthquake in bad fischau on 11 december 2013 our data suggest that tectonic strain could play a higher role on the activation of slow mass movements in the area than expected although we cannot fully exclude the co activation of the mass movement in the eisenstein cave by water saturation the presented data bring new insight into recent geodynamics of the eastern alps and the vienna basin for better interpretations and conclusions however we need a much longer period of observations

test of the eepas forecasting model on the japan earthquake catalogue the eepas every earthquake a precursor according to scale model is a method of forecasting earthquakes based on the notion that the precursory scale increase phenomenon occurs at all scales in the seismogenic process the rate density of future earthquake occurrence is computed directly from past earthquakes in the catalogue the eepas model has previously been fitted to the new zealand earthquake catalogue and successfully tested on the california catalogue

predictive modeling of the seismic cycle of the greater san francisco bay region the seismic cycle for the san francisco bay region is synthesized by a model combining the pre and post 1906 seismic histories the long term acceleration of seismic release seismic moment benioff strain release or event count in the seismic cycle and the shorter term accelerations preceding the larger earthquakes within that cycle are modeled using an empirical predictive technique called time to failure analysis in which rate of seismic release is proportional to an inverse power of the remaining time to failure the exponent of time to failure in the accelerating sequences appears to be scale invariant and the length of the full cycle is estimated at 269 50 years the 1989 loma prieta earthquake which is the culmination of the first subcycle in the present long term seismic cycle should have been predictable with an uncertainty of 2 years in time and 0 5 in magnitude although the specific location at loma prieta was not predictable by this technique if our model is correct and if the loma prieta earthquake is the culmination of a subcycle the san francisco bay region should be entering a relatively long 20 50 years period of seismic quiescence above magnitude 6 a great earthquake such as the 1906 san francisco event would appear to be more than a century in the future

biostratigraphic constraints on formation and timing of accretion in a subduction complex an example from the franciscan complex of northern california the determination of the total age coverage of pelagic bedded chert is particularly important in studies of ancient accretionary complexes because the time span represents the minimum travel time of an oceanic plate before accretion at an island arc or continental margin the yolla bolly terrane of the franciscan complex consists of rare metabasalt overlain by bedded radiolarian chert which in turn is overlain by metagraywacke and subordinate slaty mudstone and conglomerate the bedded chert ranges in age from aaleian early middle jurassic to tithonian latest jurassic a lithologic gradation from pelagic bedded chert through hemipelagic siliceous mudstone occurred during the tithonian and thus marks the arrival of the oceanic sediments at the continental margin the tithonian age also agrees with previously reported tithonian to valanginian early cretaceous fossils in the overlying terrigenous metagraywacke both chert and metagraywacke are intruded by gabbroic sills suggesting off ridge volcanism

metamorphic core complexes of cordilleran type in the cyclades aegean sea greece the islands of ios and naxos in the cycladic archipelago greece contain elongate domes over which a pervasive north to north northeast stretching lineation is warped these islands may be metamorphic core complexes of cordilleran type involving middle crustal rocks drawn upward and outward from underneath the sedimentary basins now 100 km to the south from ca 25 ma onward during uplift the crystalline rocks now exposed on the islands were deformed noncoaxially in the deeper levels of a major shallow dipping ductile shear zone this shear zone may have connected with low angle normal faults in its upper levels because it is probable that its later history involved the metamorphic complexes being dragged out from under a stretching and fracturing upper plate composed mainly of unmetamorphosed sedimentary and ophiolite suite rocks this model can be extended to explain the exhumation of the high pressure low temperature metamorphic rocks on crete which with the cyclades forms a distended paired metamorphic belt separated by an active sedimentary basin