the formation of turbidity maximum zones by minor axis tidal straining in regions of freshwater influence abstractthis study investigates the influence of tidal straining in the generation of turbidity maximum zones tmz which are observed to extend for tens of kilometers along some shallow open coa

localization of intermediate term earthquake prediction relative seismic quiescence within a region which has already been diagnosed as having entered a time of increased probability tip for the occurrence of a strong earthquake can be used to refine the locality in which the earthquake may be expected to occur a simple algorithm with parameters fitted from the data in northern california preceding the 1980 magnitude 7 0 earthquake offshore from eureka depicts relative quiescence within the region of a ttp the procedure was tested without readaptation of parameters on 17 other strong earthquake occurrences in north america japan and eurasia most of which were in regions for which a tip had been previously diagnosed the localization algorithm successfully outlined a region within which the subsequent earthquake occurred for 16 of these 17 strong earthquakes the area of prediction in each case was reduced significantly ranging between 7 and 25 of the total area covered by the tip

test of the predictability of the pi method for recent large earthquakes in and near tibetan plateau five large earthquakes of m 7 0 based on the magnitude scale of the china earthquake networks center occurred in and near the tibetan plateau during 2008 2014 including the wenchuan m8 0 earthquake on may 12 2008 bjt in this paper the tibetan plateau was chosen to be the study region and calculating parameters of pattern informatics pi method with grid of 1 1 and forecasting time interval of 8 years were employed for the retrospective study according to the previous studies for m7 earthquake forecasting the sliding step of forecasting interval was 1 year and the hotspot diagrams of each forecasting interval since 2008 were obtained year by year the relationships among the hotspots and the m 7 0 earthquakes that occurred during the forecast intervals were studied the predictability of pi method was tested by verification of receiveroperating characteristic curve roc and r score the results show that the successive obvious hotspots occurred during the sliding forecasting intervals before four of the five earthquakes while hotspots only occurred in one forecasted interval without successive evolution process before one of the five earthquakes which indicates that four of the five large earthquakes could be forecasted well by pi method test results of the predictability of pi method by roc and r score show that positive prospect of pi method could be expected for long term earthquake forecast

the vertical structure of turbulent dissipation in shelf seas abstract the free fall fly profiler has been used to determine the variation in energy dissipation in the water column over a tidal cycle at mixed and stratified sites in the irish sea it was found that exhibits a strong m4 variation with a pronounced phase lag that increases with height above the bed in mixed conditions this m4 signal which extends throughout the water column is reasonably well reproduced by turbulent closure models of the vertical exchange in the summer stratified situation the m4 signal in is confined to about 40 m above the seabed with phase delays of more than 4 h relative to the seabed the lowest levels of dissipation 10 5 w m 3 measured in the pycnocline are significantly above the system noise level and much higher than predicted by a model using the mellor yamada level 2 closure scheme my2 0 however when allowance is made for the diffusion of tke the model my2 2 simulates the depth time distribution of dissipation in the stratified case satisfactorily if

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

precursory seismic quiescence seventeen cases of precursory seismic quiescence to mainshocks with magnitudes fromml 4 7 toms 8 0 are summarized the amount of rate decrease ranges from 45 to 90 the significance of these changes varies between 90 and 99 99 the assumption that the background rate is approximately constant is fulfilled in most crustal volumes studied all quiescence anomalies seem to have abrupt beginnings and the rate during the anomalous period is fairly constant the duration of the precursors ranges from 15 to 75 months and it is not clear what factors determine that time at least three successful predictions have been based on seismic quiescence these cases have shown that mainshocks can be predicted based on quiescence but they have also shown that the interpretation of the data in real time is difficult and nonunique if a false alarm is defined as a period of quiescence with a significance level larger than a precursory quiescence in the same tectonic area then we estimate based on searches in four areas that the false alarm rate may be on the order of 50 failure to predict may be expected in perhaps 50 of mainshocks even in carefully monitored areas quiescence cannot be used as a precursor in tectonic environments with low seismic activity most characteristics of the phenomenon are still poorly defined but data exist which probably permit at least a doubling of the presently available data on case histories

combined effects of wind tide and horizontal density gradients on stratification in estuaries and coastal seas abstract the aim of this one dimensional water column study is to combine modified versions of three characteristic parameters for periodic tidal flow under the influence of a longitudinal buoyancy gradient the horizontal richardson number the inverse strouhal number and the inverse ekman number into a parameter space study including constant wind forcing from various directions it is shown how the underlying dynamical equations can be cast into nondimensional form depending mainly on these three nondimensional parameters plus the relative wind speed and the wind direction idealized model simulations are carried out for the whole realistic range of horizontal richardson and inverse strouhal numbers for various latitudes showing the amplitude of the tidally induced stratification for a wide range of scenarios it is found that classical threshold values for the horizontal richardson number indicating the switch from periodic stratification to permanent stratification are valid only for special cas

effects of tidal straining on the semidiurnal cycle of dissipation in the rhine region of freshwater influence comparison of model and measurements 1 the rhine region of freshwater influence in the north sea is a region of the coastal ocean that exhibits strong cross shore density gradients interacting with the progressive kelvin tidal wave which generates mixing when mixing is low enough to allow stratification to develop the stratification modifies the tidal currents and generates a strong tidal shear that will strain the density gradients generating a semidiurnal cycle of stratification observations of turbulent kinetic energy dissipation during calm conditions show that the bottom half of the water column has a predominantly m 4 cycle higher values of occurring during flood flow are associated with the residual flow in that direction following the strong peak in dissipation near the bed enhanced dissipation is apparent extending up the water column in the upper part of the water column shows a predominantly m 2 variation with the maximum occurring at a time when vertical stability is negligible and the effect of tidal straining is to create instability in the water column as the cross shore shear forces higher salinity water over fresher water the inference is that potential energy released by straining is responsible for convective motions and hence the enhanced turbulent activity observed the cycle of stratification and dissipation has been simulated using a one dimensional mellor yamada levels 2 and 2 2 turbulence closure model the model correctly predicts the amplitude and phase of the stratification while the model is in qualitative agreement in the description of the dissipation and its variability the absolute values of appear to be too high

neo deterministic seismic hazard and pattern recognition techniques time dependent scenarios for north eastern italy an integrated neo deterministic approach to seismic hazard assessment has been developed that combines different pattern recognition techniques designed for the space time identification of impending strong earthquakes with algorithms for the realistic modeling of seismic ground motion the integrated approach allows for a time dependent definition of the seismic input through the routine updating of earthquake predictions the scenarios of expected ground motion associated with the alarmed areas are defined by means of full waveform modeling a set of neo deterministic scenarios of ground motion is defined at regional and local scales thus providing a prioritization tool for timely preparedness and mitigation actions constraints about the space and time of occurrence of the impending strong earthquakes are provided by three formally defined and globally tested algorithms which have been developed according to a pattern recognition scheme two algorithms namely cn and m8 are routinely used for intermediate term middle range earthquake predictions while a third algorithm allows for the identification of the areas prone to large events these independent procedures have been combined to better constrain the alarmed area the pattern recognition of earthquake prone areas does not belong to the family of earthquake prediction algorithms since it does not provide any information about the time of occurrence of the expected earthquakes nevertheless it can be considered as the termless zero approximation which restrains the alerted areas e g defined by cn or m8 to the more precise potential location of large events italy is the only region of moderate seismic activity where the two different prediction algorithms cn and m8s i e a spatially stabilized variant of m8 are applied simultaneously and a real time test of predictions for earthquakes with magnitude larger than a given threshold namely 5 4 and 5 6 for cn algorithm and 5 5 for m8s algorithm has been ongoing since 2003 the application of the cn to the adriatic region which is relevant for seismic hazard assessment in the northeastern part of the italian territory is also discussed examples of neo deterministic scenarios are provided at regional and local scale and for the cities of trieste and nimis friuli venezia giulia region where the knowledge of the local geological conditions permitted a detailed evaluation of the expected ground motion

semidiurnal switching of stratification in the region of freshwater influence of the rhine observations in the rhine region of freshwater influence rofi system in the north sea show evidence of large semidiurnal oscillations in stability superimposed on a mean stratification occurring throughout the stratified region at times of reduced mixing the amplitude of this semidiurnal variation is of the same order as the mean stability and frequently results in conditions being mixed or nearly mixed once per tide it is deduced that this semidiurnal variation results primarily from cross shore tidal straining which interacts with the density gradient to induce stratification this conceptual picture of the contributing processes has been tested in a one dimensional point model forced by the observed slopes and the local density gradients the model exhibits the same qualitative behavior as the observations produces oscillations in stratification of the amplitude observed and confirms the critical role of cross shore tidal straining the large cross shore shear nder stratified conditions is identified with the changes in ellipse configuration which are observed between mixed and stratified conditions the occurrence of semidiurnal variations in stability in the rhine rofi is thus inferred to be a consequence of the development of mean stability whenever the horizontal density gradients relax in conditions of low stirring

premonitory spreading of seismicity over the faults network in southern california precursor accord 1 we establish a connection between geometry of the faults network in a region and seismicity preceding the strong earthquakes in the intermediate term timescale of years previous studies of observed and computer simulated seismicity demonstrated that strong earthquakes are preceded in that timescale by the rise of seismic activity in a lower magnitude range here we explore a complementary phenomenon spreading of activity over the fault network this phenomenon is depicted by the seismicity pattern accord defined as a simultaneous rise of seismicity in a sufficiently large number of fault zones hence its name pattern accord has been found recently in synthetic seismicity generated by the colliding cascades cc model the present study demonstrates this pattern in observed seismicity of southern california we applied to observations a prediction algorithm based on the pattern accord scaled to the target magnitude 7 5 the pattern accord emerges within a few years before each of the three largest earthquakes in southern california kern county 1952 landers 1992 and hector mine 1999 and at no other time scaled to the target magnitude interval from 6 5 to 7 4 the pattern accord precedes six out of nine earthquakes the duration of alarms in both cases is about 30 of the time considered we repeated prediction with different combinations of adjustable numerical parameters of the algorithm summing up the success and error scores on an error diagram this numerical experiment shows that the prediction results are stable under moderate variations of adjustable parameters the final test would be as always an advance prediction the pattern accord has a simple physical explanation connected with equilibrium of the crustal blocks system under the impact of tectonic driving forces at the same time accord is a manifestation of a broader phenomenon premonitory increase of earthquakes correlation range the latter phenomenon was found for the first time in the cc model although it was hypothesized by one of the authors much earlier

precursory activation of seismicity in advance of the kobe 1995 m 7 2 earthquake a succession of precursory changes of seismicity characteristic to earthquakes of magnitude 7 0 7 5 occurred in advance of the kobe 1995 m 7 2 earthquake using the japan meteorological agency jma regional catalog of earthquakes the m8 prediction algorithm keilies borko and kossobokov 1987 recognizes the time of increased probability tip for an earthquake with magnitude 7 0 7 5 from july 1991 through june 1996 the prediction is limited to a circle of 280 km radius centered at 33 5 n 133 75 e the broad area of intermediate term precursory rise of activity encompasses a 175 by 175 km square where the sequence of earthquakes exhibited a specific intermittent behavior the square is outlined as the second approximation reduced area of alarm by the mendocino scenario algorithm msc kossobokov et al 1990 moreover since the m8 alarm starts there were no swarms recorded except the one on 9 26 nov 1994 located at 34 9 n 135 4 e time location and magnitude of the 1995 kobe earthquake fulfill the m8 msc predictions its aftershock zone ruptured the 54 km segment of the fault zone marked by the swarm directly in the corner of the reduced alarm area the kobe 1995 epicenter is less than 50 km from the swarm and it coincides with the epicenter of the m 3 5 foreshock which took place 11 hours in advance

increased correlation range of seismicity before large events manifested by earthquake chains earthquake chains are clusters of moderate size earthquakes which extend over large distances and are formed by statistically rare pairs of events that are close in space and time neighbors earthquake chains are supposed to be precursors of large earthquakes with lead times of a few months here we substantiate this hypothesis by mass testing it using a random earthquake catalog also we study stability under variation of parameters and some properties of the chains we found two invariant parameters they characterize the spatial and energy scales of earthquake correlation both parameters of the chains show good correlation with the magnitudes of the earthquakes they precede earthquake chains are known as the first stage of the earthquake prediction algorithm reverse tracing of precursors rtp now tested in forward prediction a discussion of the complete rtp algorithm is outside the scope of this paper but the results presented here are important to substantiate the rtp approach

premonitory raise of the earthquakes correlation range lesser antilles abstract we apply to the observed seismicity of lesser antilles a short term earthquake precursor which has been recently found by analysis of synthetic seismicity the latter was generated by a lattice type colliding cascades model of interacting elements precursor named roc depicted premonitory increase of the earthquakes correlation range here this precursor is used as a second approximation to the intermediate term prediction as a first approximation we use the alarms determined in the previous publication by the algorithm seismic reversal sr it depicts premonitory reversal of territorial distribution of seismicity we consider combined performance of both algorithms in prediction of earthquakes with magnitude 5 5 or above four such earthquakes occurred in the territory considered during 1984 1998 the alarms occupy 0 5 of the total time space three alarms happened to be correct two alarms were false and one earthquake was missed by prediction the alarms are very stable to variation of adjustable parameters of prediction method in view of this stability such a prediction is unusually good even for retrospective analysis we present this prediction method as a hypothesis to be tested on advance prediction

non linear dynamics of the lithosphere and intermediate term earthquake prediction abstract the lithosphere of the earth is structured as a hierarchical system of volumes of different sizes from about 10 tectonic plates to about 10 25 grains of rock their relative movement against the forces of friction and cohesion is realized to a large extent through earthquakes the movement is controlled by a wide variety of independent processes concentrated in the thin boundary zones between the volumes the boundary zone has a similar hierarchical structure consisting of volumes separated by boundary zones etc altogether this hierarchy of volumes and multitude of processes compose the lithosphere into a large non linear complex system upon coarse graining the integral mesoscale empirical regularities emerge indicating a wide range of similarity collective behavior and the possibility of earthquake prediction this approach led to new paradigms in the dynamics of the lithosphere and on the practical side created a capacity to predict from 70 to 90 of large earthquakes with alarms occupying 10 20 of the time space considered such predictions may be used to undertake earthquake preparedness measures which would prevent a considerable part of the damage although far from the total damage the methodology linking prediction with preparedness was developed it may help a disaster management authority to choose the preparedness measures allowing for the currently realistic accuracy of predictions a large scale experiment in advance prediction of large earthquakes worldwide has been launched to test the prediction algorithms the test is unprecedented in rigor and coverage the forecasts are communicated with due discretion to several dozen leading scientists and administrators in many countries among already predicted earthquakes are all the last eight great ones with magnitude 8 and more the major drawback is the rate of false alarms the possibility is outlined to develop a new generation of prediction methods with fivefold increase in accuracy and the transition to short term prediction the links with prediction of geotechnical and engineering disasters are established scenarios of transitions to a large earthquake happen to share some features with a broader class of catastrophes this experience now opens as yet untapped possibilities for reduction of technological disasters

testing earthquake prediction methods the west pacific short term forecast of earthquakes with magnitude mwhrv 5 8 in his paper kossobokov investigates the e ciency of our short term forecast for two western paciflc regions although we agree with the basic results of his evaluation that the forecast statistics is much better than a random guess we have reservations about his deflnition of earthquake prediction some of his tests and his interpretation of the test results we distinguish between deterministic earthquake predictions and statistical forecasts we argue that some techniques used by kossobokov may not be appropriate for testing our forecasts and discuss other testing methods based on the likelihood function we demonstrate that kossobokov s null hypothesis may be biased and this bias can in uence some of his conclusions we show that contrary to kossobokov s statement our algorithm predicts mainshocks when they are preceded by foreshocks

the cycle of turbulent dissipation in the presence of tidal straining in regions of large horizontal density gradient tidal straining acts to produce a periodic component of stratification that interacts with turbulent mixing to control water column structure and flow a 25 h series of measurements of the rate of dissipation of turbulent kinetic energy e in the liverpool bay region of freshwater influence rofi have revealed the form of this interaction and indicate substantial differences from regions where horizontal gradients are weak in the rofi system there is a pronounced difference between flood and ebb regimes during the ebb the water column stratifies and strong dissipation is confined to the lower half of the water column by contrast during the flood stratification is eroded with complete vertical mixing occurring at high water and high values of dissipation 3 mw m23 extending throughout the water column the cycle of dissipation is therefore predominantly semidiurnal in the upper layers whereas near the bottom boundary the principal variation is at the m4 frequency as observed in regions of horizontal uniformity toward the end of the flood phase of the cycle tidal straining produces instabilities in the water column that release additional energy for convective mixing confirmation of increased vertical motions throughout the water column during the late flood and at high water is provided by measurements of vertical velocity and the error velocity from a bottom mounted acoustic doppler current profiler

phenomenon of local seismic reversal before strong earthquakes abstract we explore here the following hypothetical phenomenon the territorial distribution of low magnitude seismicity is reversed within several months prior to a strong earthquake in the area surrounding its source the diameter of this area is on the order of 100 km this phenomenon is investigated for the lesser antilles and southern california on that basis we suggest a hypothetical earthquake prediction algorithm to be tested by advance prediction retrospective application of the algorithm and the first three years of advance prediction in lesser antilles give encouraging results in comparison with well known intermediate term prediction algorithms m8 cn and mendocino scenario the sr algorithm gives smaller time space areas of the alarm it has a serious disadvantage however the catalogue should be complete for a longer period of time and for smaller magnitudes than are required in cn and m8

global pattern of earthquakes and seismic energy distributions insights for the mechanisms of plate tectonics article i nfo in this paper we analyse the distributions of number of events n and seismic energy e on the earth s surface and along its radius as obtained from the global declustered catalogue of large independent events m 7 0 dissipating about 95 of the earth s elastic budget the latitude distribution of the seismic event density is almost symmetric with respect to the equator and the seismic energy flux distribution is bimodal both have their medians near the equator so that they are equally distributed in the two hemispheres this symmetry with respect to the equator sug gests that the earth s rotational dynamics contributes to modulate the long term tectonic processes the distributions of number and energy of earthquakes versus depth are not uniform as well 76 of the total earth quakes dissipates about 60 of the total energy in the first 50 km only 6 of events dissipates about 20 of the total amount of energy in a narrow depth interval at the lower boundary of the upper mantle 550 680 km therefore only the remaining 20 of energy is released along most of the depth extent of subduction zones 50 550 km since the energetic release along slabs is a minor fraction of the total seismic budget the role of the slab pull appears as ancillary if any in driving plate tectonics moreover the concentration of seismic release in the not yet subducted lithosphere suggests that the force moving the plates acts on the uppermost lithosphere and contemporaneously all over the earth s outer shell again supporting a rotational tidal modulation

application of linked stress release model to historical earthquake data comparison between two kinds of tectonic seismicity the linked stress release model incorporating a slow buildup of stress within a seismic region its stochastic release through earthquakes and transfer between seismic regions is applied to fit historical data from two typical kinds of seismicity earthquakes occurring in intraplate north china and plate boundary new zealand regions the best model among different modifications of the basic model which may reflect on a possible geophysical mechanism for earthquake occurrences is obtained in terms of akaike information criterion for both tectonic regions studied the linked stress release model fits the new zealand data better than a collection of independent simple models but is nearly indistinguishable from the simple stress release model in the case of north china the seismicity in a plate boundary region due to subduction is more active and complex than that in an intraplate region due to collision between tectonic plates the results highlight the major differences in tectonic seismicity especially the heterogeneities of tectonic stress fields and dynamic triggering mechanism with evidence that the crust may lie in a near critical state

global scale analysis of seismic activity prior to 2004 sumatra andaman mega earthquake abstract following our experience in intermediate term monitoring of seismicity before large earthquakes worldwide and in some regions we apply a similar approach to the analysis of seismicity on global scale several decades before the december 26 2004 sumatra andaman mega earthquake the earth lithosphere is being considered as a single whole representing the ultimate level of the complex earth s hierarchy the study brings up the following questions are there any anomalies of the global seismicity behaviour observed in advance of the mega earthquake do these anomalies correspond to the global scale seismic patterns similar to those detected on the regional scale before great major and strong events in other words does the earth lithosphere considered as a single whole show up an approach of the mega earthquake in the way typical for events on the smaller levels of hierarchy the results of our investigation favour the positive answer to the questions specifically we found that during the decade before the sumatra andaman mega earthquake the earth lithosphere reveals at least in intermediate term scale classical symptoms of instability which can be depicted by known precursory seismic patterns these are i transformation of frequency magnitude distribution ii change in the rate of seismic activity and iii depth redistribution of activity moreover changes of dependencies between magnitudes of different types are detected at the same time the observed global scale patterns of collective behaviour of seismicity may indicate the state of criticality of the earth lithosphere before the sumatra andaman mega earthquake

short term earthquake prediction current status of seismo electromagnetics abstract loss of human lives as a result of earthquakes is caused overwhelmingly by the collapse of buildings within less than a few minutes of main shocks the most urgent countermeasure consists of two key elements one is strengthening of weak structures and the other is short term earthquake prediction short term prediction needs precursors although some promising precursors are reported the prevailing views in japan and elsewhere are overly pessimistic the pessimism largely roots in the fact that short term precursors are generally non seismic and tools developed for seismology are not designed to detect them nonetheless nationally funded large scale earthquake prediction programs always emphasize the need to reinforce seismometer networks they do not take into account the views of those in the science community who point to the importance of non seismic precursors while there are well founded causes to be skeptical the situation needs to be improved one reason for skepticism is that the observations of precursors have not yet been perfect enough and another is that some important fundamental aspects of non seismic precursors are still unresolved we review some of these problems

comment on testing earthquake prediction methods the west pacific short term forecast of earthquakes with magnitude mwhrv 5 8 by v g kossobokov in his paper kossobokov investigates the efficiency of our short term forecast for two western pacific regions although we agree with the basic results of his evaluation that the forecast statistics is much better than a random guess we have reservations about his definition of earthquake prediction some of his tests and his interpretation of the test results we distinguish between deterministic earthquake predictions and statistical forecasts we argue that some techniques used by kossobokov may not be appropriate for testing our forecasts and discuss other testing methods based on the likelihood function we demonstrate that kossobokov s null hypothesis may be biased and this bias can influence some of his conclusions we show that contrary to kossobokov s statement our algorithm predicts mainshocks when they are preceded by foreshocks

the erosion history of the central alps evidence from zircon fission track data of the foreland basin sediments fission track dating on detrital zircons of alpine debris in the swiss molasse basin provides information about the erosion history of the central alps and the thermal evolution of source terrains during oligocene times only sedimentary cover nappes and austroalpine basement units were eroded incision into austroalpine basement units is indicated by increasing importance of cretaceous cooling ages in granite pebbles upsection erosion of penninic basement units started between 25 and 20 ma early oligocene zircon ft ages show that penninic basement units were exposed at 20 ma deeper penninic units of the lepontine dome became exposed first at 14 ma contemporaneously with the opening of the tauern window in the eastern alps a middle miocene cooling rate of 40 c myr 1 is deduced for the lower penninic units of the lepontine dome

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

back analysis of short term seismic hazard indicators of larger seismic events in deep underground mines lkab kiirunavaara mine sweden back analysis for evaluation of the merits of the short term seismic hazard indicators precursors used in the mines and their potential application for early warning was carried out for fourteen seismic events that potentially caused damage in kiirunavaara mine sweden selected according to our designed criteria five short term hazard indicators seismic activity rate sar cumulative seismic moment csm energy index ei cumulative apparent volume cav and seismic apparent stress frequency asf were tested the behaviour of the indicators was studied using the parameters of all seismic events within a sphere around the hypocenter location of the analyzed seismic source within one month before the main damaging event the size of the sphere equals the estimated radius of the analyzed seismic source area of inelastic deformation mxrap software australian centre for geomechanics was used for data visualization manipulation analysis and extraction the results from the main analysis showed a good agreement between the expected and actual behaviour of the sar csm and cav indicators in overall csm and cav ranked the highest positive expected behaviour followed by sar table 3 the ei and asf ranked lowest and showed to be sensitive to the number of events within the source sphere the rate of false warnings and missed warnings was also investigated for the 25 days long period before the damaging events a similar trend was observed as for the main analysed event the results from this study can be used for further improvement of the short term hazard estimations and early warning system in deep underground mines

role of straining and advection in the intratidal evolution of stratification vertical mixing and longitudinal dispersion of a shallow macrotidal salt wedge estuary 1 a month of flow observations in the snohomish river estuary reveals the complex intratidal and fortnightly stratification mixing and dispersion dynamics in this macrotidal shallow salt wedge estuary system both salt wedge propagation and concomitant straining of the density field dominate temporal and spatial variations in stratification leading to intratidal variability of shear and mixing that differs in important ways from observations in partially mixed estuaries bottom generated turbulent kinetic energy production is enhanced during spring tides and acts in concert with straining to counteract advection and minimize vertical stratification during the spring flood tides this bottom generated mixing contributes to a buoyancy flux near the top of a well mixed layer during strong flood tides during strong ebb tides interfacial shear production and buoyancy flux occur along the sharp straining enhanced interface just before the system becomes well mixed longitudinal dispersion is less sensitive to the spring neap cycle yet exhibits strong intratidal variability reduced longitudinal dispersion is observed during the large floods relative to the rest of the tidal cycle behavior we attribute to a lack of vertical shear overall ebb tide advection and straining enhance stratification and longitudinal dispersion and allow for interfacial mixing intratidal variability which varies on the spring neap scale is a dominant feature of this estuary suggesting the importance of intratidal processes and tidally varying mixing coefficients in similar strongly stratified strongly forced estuaries

testing earthquake prediction algorithms statistically significant advance prediction of the largest earthquakes in the circum pacific 1992 1997 abstract algorithms m8 and msc i e the mendocino scenario were used in a real time intermediate term research prediction of the strongest earthquakes in the circum pacific seismic belt predictions are made by m8 first then the areas of alarm are reduced by msc at the cost that some earthquakes are missed in the second approximation of prediction in 1992 1997 five earthquakes of magnitude 8 and above occurred in the test area all of them were predicted by m8 and msc identified correctly the locations of four of them the space time volume of the alarms is 36 and 18 correspondingly when estimated with a normalized product measure of empirical distribution of epicenters and uniform time the statistical significance of the achieved results is beyond 99 both for m8 and msc for magnitude 7 5 10 out of 19 earthquakes were predicted by m8 in 40 and five were predicted by m8 msc in 13 of the total volume considered this implies a significance level of 81 for m8 and 92 for m8 msc the lower significance levels might result from a global change in seismic regime in 1993 1996 when the rate of the largest events has doubled and all of them become exclusively normal or reversed faults the predictions are fully reproducible the algorithms m8 and msc in complete formal definitions were published before we started our experiment keilis borok v i kossobokov v g 1990 premonitory activation of seismic flow algorithm m8 phys earth and planet inter 61 73 83 kossobokov v g keilis borok v i smith s w 1990 localization of intermediate term earthquake prediction j geophys res 95 19763 19772 healy j h kossobokov v g dewey j w 1992 a test to evaluate the earthquake prediction algorithm m8 u s geol surv ofr 92 401 m8 is available from the iaspei software library healy j h keilis borok v i lee w h k eds 1997 algorithms for earthquake statistics and prediction vol 6 iaspei software library

testing an earthquake prediction algorithm the 2016 new zealand and chile earthquakes the 13 november 2016 m7 8 54 km nne of amberley new zealand and the 25 december 2016 m7 6 42 km sw of puerto quellon chile earthquakes happened outside the area of the on going real time global testing of the intermediate term middle range earthquake prediction algorithm m8 accepted in 1992 for the m7 5 range naturally over the past two decades the level of registration of earthquakes worldwide has grown significantly and by now is sufficient for diagnosis of times of increased probability tips by the m8 algorithm on the entire territory of new zealand and southern chile as far as below 40 s the mid 2016 update of the m8 predictions determines tips in the additional circles of investigation cis where the two earthquakes have happened thus after 50 semiannual updates in the real time prediction mode we 1 confirm statistically approved high confidence of the m8 msc predictions and 2 conclude a possibility of expanding the territory of the global test of the algorithms m8 and msc in an apparently necessary revision of the 1992 settings

an overview on the seismic zonation and microzonation studies in india abstract the present study presents a review on the progressive development of the seismic zonation map of india both from official agencies and also from independent individual studies the zonation map have been modified and updated regularly with the occurrence of major destructive earthquakes over the years in the indian subcontinent with the addition of new data this study discusses the criteria chosen for the progressive zonation and the major earthquakes that were responsible for retrospection of the earlier published maps the seismic zonation maps of india have also been prepared by various independent workers by adopting different approaches to achieve the purpose of the zonation despite the endeavors from various sources to provide a solution for the problem of earthquake hazards in india there were many limitations on the zonation map as it gives the picture at a regional scale mostly on the bedrock level without addressing the local site conditions but nevertheless the seismic zonation map gives basic guidelines for any region to know the hazard scenario and if any city or urban population is under threat from seismic point of view further site specific seismic microzonation may be carried out in the international scenario the global seismic hazard assessment program gshap in 1999 prepared a hazard map for world in terms of peak ground acceleration pga with a 10 probability of exceedance in 50 years but it turned out to be an underestimation of the hazard parameter when compared with the observed pga to tackle the problem of seismic hazards there was a need to have a detail study on the local site conditions in terms of its geological geophysical and geotechnical properties with the advent of better instrumentation and knowledge on the mechanics of earthquakes it was possible to identify zones of hazards at a local level and this gives rise to the study of seismic microzonation seismic microzonation work has been carried out in india in some of the strategic important mega cities and industrial build up that has the potential of being damaged from future earthquakes as has been shown in the past though the microzonation map is not the final output map as it can still be updated at later stage with more input data it does provide a more realistic picture on the site specific seismic hazard