evidence of non extensive statistical physics of the lithospheric instability approaching the 2004 sumatran andaman and 2011 honshu mega earthquakes abstract in the present study we demonstrate in the frame of non extensive statistical physics significant deviations of the global seismic activity from a quasi stationary regime before sumatra andaman and honshu mega earthquakes suggesting the existence of a global scale intermediate term non extensive tectonic premonitory of impending mega earthquake processes in the lithosphere using non extensive statistical mechanics we describe the frequency moment the inter event time and distance distributions interpreting sumatran s 2004 and honshu 2011 earthquakes influence on these at a phenomenological level we find that global seismicity is described by non extensive statistical mechanics nesm and that the seismic moment and the earthquake inter event time distributions reflect a sub extensive system where long range interactions are important using the cross over formulation of nesm leads us to the conclusion that the seismic moment distribution of moderate events yields thermodynamic q values of qm 1 6 which seem to be constant for the duration of the sumatra and honshu earthquake preparation while rm which describes the seismic moment distribution of great events varies from 1 to 1 5 as we approach the mega events the inter event time and inter event distance distributions with q 1 5 and qd 0 3 respectively support the conclusion of non extensive spatio temporal duality suggesting that global shallow moderate seismicity with 5 5

anisotropy beneath hawaii from surface wave particle motion observations observed polarization ellipses for fundamental mode surface waves observed at a digital station in hawaii deviate from those expected for isotropic models of crust and mantle structure for that region the anomalous motion occurs as rotations of the ellipse about all three axes in a cartesian corrdinate system the largest and most consistent deviations occur as anomalous slopes of the ellipse about the horizontal axis transverse to the direction of propagation

exsolution of magmatic volatile phases from cl enriched mineralizing granitic magmas and implications for ore metal transport abstract to understand cl dissolution in aluminosilicate liquids and the exsolution of cl rich magmatic volatile phases experiments were conducted to determine the solubility of nacl kcl and h2o in felsic liquids at 0 5 and 2 kbar the cl content of h2o poor nacl saturated and kcl saturated silicate liquids is low i e 1 3 wt to very low i e 0 2 wt and varies with changes in pressure and composition the cl concentration increases with the f concentration and the molar al na ca mg si ratio of the liquid and decreases with increasing activity of h2o in the system exsolution of a volatile phase depends on the partial pressures of all dissolved volatiles and low cl solubilities in nacl saturated and kcl saturated silicate liquids imply that exsolution of a cl bearing volatile phase will occur early in cl bearing granitic magmas i e prior to extensive melt crystallization and or at comparatively low water fugacities the solubility behavior of h2o and cl is very similar to that of co2 and h2o in felsic liquids small quantities of co2 are known to facilitate volatile phase exsolution holloway 1976 and in a similar manner volatile phases may exsolve early in cl enriched granite magmas whereas 5 to 6 wt dissolved h2o is necessary for volatile phase exsolution from a co2 free and cl free haplogranite liquid at 2 kbar and 800 c a cl rich brine will exsolve if the liquid contains only 1 wt h2o and 0 26 wt cl at the same conditions these new solubility data are interpreted in light of h2o f and cl concentrations in felsic liquids determined from silicate melt inclusions to constrain the exsolution of cl bearing magmatic volatile phases from mineralizing granitic magmas felsic magmas genetically associated with cu porphyry and mo porphyry mineralization contain sufficient h2o and cl to become saturated with respect to a hypersaline brine without strong pressure reduction boiling of the volatile phase i e exsolution of immiscible vapor and brine or strong volatile enrichment resulting from extensive crystal fractionation experiments were also conducted to investigate the solubility of mo in highly saline volatile phases coexisting with granitic liquids at 2 and 0 5 kbar the apparent partition coefficient for mo in the volatile phase s relative to silicate liquid d mo is defined as the computed concentration of mo in a volatile phase or phases the measured concentration of mo in granite glass d mo ranges from 8 to 80 as the nacl and kcl content of the volatile phase s increases from 15 to 90 wt because mo does not complex with cl in aqueous fluids it appears that mo solubility may be a strong function of the activity of na and k in alkali chloride rich volatile phases

seismic activity on neighbouring faults as a long term precursor to large earthquakes in the san francisco bay area activity in moderate size earthquakes accelerated in the several decades before the large california earthquakes of 1989 1906 and 1868 this type of precursor seems to require the presence of several major faults in close enough proximity to one another that moderate size shocks are selectively triggered on surrounding faults during the latter stages of the cycle of strain buildup to large earthquakes it may be possible to use quantitative aspects of similar seismic precursors to make predictions of large earthquakes on timescales of a few years to one decade

magmatic immiscibility and fluid phase evolution in the mount genis granite southeastern sardinia italy the mount genis granite is one of the post tectonic intrusives emplaced late in the magmatic history of the hercynian batholith in sardinia devitrified silicate melt inclusions are present in some magmatic rock forming and miarolitic quartz these magmatic remnants show initial melting at 680 720 c high temperature observations 700 800 c revealed the presence in some of the inclusions of mixed hydrosaline melt l1 and silicate melt l2 with extremely variable l1l2 ratios electron microprobe analyses indicate l1 to be k na dominated chlorides inclusions of mixed silicate and hydrosaline melts are interpreted to have been formed by heterogeneous trapping of two immiscible fluid phases silicate hydrosaline after second boiling most likely during the final crystallization stage magma derived brines 63 eq wt nacl circulated at subsolidus conditions from 600 c and were retained in the miarolitic cavities down to about 400 c fluid unmixing occurred locally in the miarolitic cavities from 550 to 412 c at temperatures of 400 to 100 c the microgranite was invaded by diluted waters 4 5 eq wt nacl a possible model for fluid evolution begins with a hydrosaline melt exsolving from the magma at the late magmatic stage the absence of boiling within the volatile hydrosaline system shows that brines can occur by direct magmatic immiscibility the comprehensive hydrothermal evolution suggests a nearly isobaric cooling path with local boiling episodes in the miaroles probably in coincidence with invasion of external waters

temporal changes in the cumulative piecewise gradient of a variant of the gutenberg richter relationship and the imminence of extreme events abstract it is generally found that the relative frequencies of occurrence of earthquakes of different magnitudes in seismogenic zones have a power law distribution for a long term dataset the overall slope of this logarithmically transformed distribution is usually indicated by a best fit straight line and expressed as a b value this slope is stable and normally lies between 0 8 and 1 2 the actual value depending on the region examined and the threshold selected for data completeness the linearity of the distribution can be used to make statistical inferences about the potential for larger events over the long run and with appropriate reservations may even be extrapolated to magnitudes that are beyond recent experience we suggest the same information can also be viewed over shorter intervals in terms of an empirical piecewise distribution with relative frequencies of occurrence at adjacent magnitude steps controlling the local slope of the distribution an emergence through time of an excess number of lower magnitude earthquakes causes temporal changes to appear in the low end piecewise gradients of this distribution a marked excursion away from an overall uniform trend for the particular zone may be indicative of an imminent larger event on two separate occasions in 1982 and 1997 such temporal variations were seen in the magnitude distributions of sequences of events near tobago west indies and used to anticipate subsequent damaging mainshocks the recognition of temporal departures from overall linearity of the magnitude frequency relation in a suitable dataset may thus provide an evidential element that can contribute to earthquake forecasting this phenomenological approach was used in the analysis of the neic global dataset of earthquakes of magnitude 6 1 and bigger for the period 1973 2003 to explore its wider applicability trends in the piecewise gradients of the global data were interpreted as pointing to an imminent great earthquake perhaps exceeding magnitude 8 5 such an event did occur shortly afterwards in the form of the great sumatran earthquake of 2004 12 26 following that event global magnitude production continued to exhibit sharp imbalances in the lower magnitude bins indicating that another similar event was likely the second sumatran earthquake on 2005 03 28 satisfied that projection since that time a magnitude production imbalance persists in the global dataset suggesting the system could be poised to output an earthquake or earthquakes in the magnitude range 8 6 9 0 or even greater this contribution describes the piecewise gradient approach and examines its application to global earthquake data

effect of an earthquake occurrence on the flow intensity of the subsequent events aftershocks or swarms indicate increase of the flow intensity in the vicinity of the initial earthquakes by normalizing their number according to the dynamic range of the standard frequency magnitude distribution the increase or positive aftereffect property of the initial earthquakes can be compared for different magnitude intervals periods of time or regions after applying accurate formal algorithm of aftershock identification it is possible to study negative aftereffect of the main events nonaftershocks in the catalog negative aftereffect means decrease of the probability of successive events in a time space vicinity of the main event when the aftershocks are over the negative effect is the most important part of the seismic cycle and seismic gaps approach global statistical test give high confidence level for the relative decrease in intensity of the flow of the events withm 7 in the first 20 25 years after the events withm 8 in their 1o vicinities in the total time period under study of approximately 60 years the decrease approximates 32 of the undisturbed intensity of the flow ofm 7 events in the vicinities self similar negative aftereffect was observed 3 7 years after 6 m 7 events it totals approximately 18 of the undisturbed intensity another type of self similarity of seismic regime with respect to the negative aftereffect is the decrease of probabilities of aftershocks with large magnitudes in aftershock sequences when we have adequate dynamic range in the catalog for the study of this property for example for main events withm 7 in the catalog with low cut off limitm 4 the statistical significance of the negative aftereffect is clear however the absolute value of the effect is also rather small about 10 which means that in 90 of the cases the aftershock sequences do not experience lack of energy due to the main shock energy release and follow a standard magnitude distribution for earthquakes in the entire catalog the small values of the negative aftereffect apparently indicate partial stress relase by earthquakes and may explain short recurrence time intervals after major earthquakes observed periodically in different places

southern hemisphere forcing of pliocene δ18o and the evolution of indo asian monsoons monsoon phase relationships consistent with direct orbital forcing across the entire indo asian region including marine and terrestrial proxies from the chinese loess plateau the south china sea and the arabian sea strong pliocene summer and winter monsoons were in phase with one another strengthened at obliquity minima and precession minima the summer monsoon was also strengthened at precession maxima yielding a semiprecession spectral signal strong pliocene monsoons at orbital extremes indicate a direct response to fast physics processes including sensible heating and cooling of the asian landmass and for the summer monsoon the export of latent heat from the southern indian ocean as northern hemisphere ice volume grew into the pleistocene the timing of strong winter and summer monsoons drifted apart becoming influenced by the combined effects of fast physics and slow physics ice volume variables the phase of strong winter monsoons shifted toward ice maxima and the phase of strong summer monsoons shifted toward ice minima

the lithosphere of the earth as a nonlinear system with implications for earthquake prediction the lithosphere of the earth can be viewed as a hierarchy of volumes from tectonic plates to 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 a boundary zone has a similar hierarchical structure consisting of volumes separated by boundary zones etc altogether these processes transform the lithosphere into a large nonlinear system featuring instability and deterministic chaos from this background some integral grossly averaged empirical regularities emerge indicating a wide range of similarity collective behavior and the possibility of intermediate term earthquake prediction

spatiotemporal patterns in the energy release of great earthquakes for the past 80 years the energy released in great strike slip and thrust earthquakes has occurred in alternating cycles of 20 to 30 years this pattern suggests that a global transfer mechanism from poloidal to toroidal components of tectonic plate motions is operating on time scales of several decades the increase in seismic activity in california in recent years may be related to an acceleration of global strike slip moment release as regions of shear deformation mature after being reached by stresses that have propagated away from regions of great subduction decoupling earthquakes in the 1960s

metal fractionation between magmatic brine and vapor determined by microanalysis of fluid inclusions the major and trace element compositions of individual fluid inclusions from a range of magmatic hydrothermal ore deposits were analyzed by laser ablation inductively coupled plasma mass spectrometry to explore the behavior of ore forming components during fluid phase separation boiling in high temperature saline fluid systems data from 13 samples showing unambiguous evidence for coeval trapping of a liquid brine and a coexisting vapor phase identify two groups of elements with drastically different geochemical behavior na k fe mn zn rb cs ag sn pb and tl preferentially partition into the brine probably as cl complexes whereas cu as au probably as hs complexes and b selectively partition into the vapor fluid phase separation is probably a major previously underestimated process in the chemical differentiation that contributes to the extreme range of selective element enrichments in magmatic hydrothermal systems from deep plutons through porphyry style and greisen deposits to epithermal mineralization and volcanic fumaroles

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

minimum magnitude of completeness in earthquake catalogs examples from alaska the western united states and japan we mapped the minimum magnitude of complete reporting m c for alaska the western united states and for the junec earthquake catalog of japan mc was estimated based on its departure from the linear frequency magnitude relation of the 250 closest earthquakes to grid nodes spaced 10 km apart in all catalogs studied mc was strongly heterogeneous in offshore areas the mc was typically one unit of magnitude higher than onshore on land also mc can vary by one order of magnitude over distance less than 50 km we recommend that seismicity studies that depend on complete sets of small earthquakes should be limited to areas with similar mc or the minimum magnitude for the analysis has to be raised to the highest com mon value of mc we believe that the data quality as reflected by the mc level should be used to define the spatial extent of seismicity studies where mc plays a role the method we use calculates the goodness of fit between a power law fit to the data and the observed frequency magnitude distribution as a function of a lower cutoff of the magnitude data mc is defined as the magnitude at which 90 of the data can be modeled by a power law fit mc in the 1990s is approximately 1 2 0 4 in most parts of california 1 8 0 4 in most of alaska aleutians and panhandle excluded and at a higher level in the junec catalog for japan various sources such as ex plosions and earthquake families beneath volcanoes can lead to distributions that cannot be fit well by power laws for the hokkaido region we demonstrate how neglecting the spatial variability of m c can lead to erroneous assumptions about deviations from self similarity of earthquake scaling

fluid inclusion evidence for magmatic silicate saline co2 immiscibility and geochemistry of alkaline xenoliths from ventotene island italy abstract fluid and melt inclusions and geochemical features of alkali syenite mafic and ultramafic cumulate xenoliths in the last ignimbritic event volcanism up to 300 ky b p at the island of ventotene in the pontine archipelago gaeta gulf were investigated to establish the genesis and evolution of the fluids trapped in the inclusions ranges in lead isotopic compositions of the xenoliths as a group are narrow 206pb 204pb 18 778 18 864 207pb 204pb 15 641 15 701 208pb 204pb 38 858 39 090 the values overlap among the groups implying that the xenoliths are closely related the xenoliths straddle the best fit line describing the regional nw se variation of values for uranogenic pb in volcanic rocks from the roman alkaline province the similarity between the xenoliths and volcanic rocks permits the interpretation that the xenoliths are representative of the source region of the volcanic rocks residues after partial melting of the source region or fractional crystallization of the volcanic rocks or even that the xenoliths represent assimilants obtained during the evolution of the magmas that produced the volcanic rocks xenoliths belonging to the ultramafic mafic cumulate group contain only silicate melt inclusions vapor bubble droplets of an opaque phase and rarely some co2 trapped in silicate melt inclusions xenoliths in the alkali syenite group have three types of fluid inclusions 1 single phase vapor and silicate melt inclusions 2 two phase silicate melt salt silicate melt co2 v aqueous l v and silicate melt vapor inclusions and 3 three phase and multiphase inclusions co2 l co2 v h2o silicate melt saline melt h2o birefringent or opaque trapped minerals h2o salt silicate glass birefringent trapped minerals during heating experiments melting of salt occurs at temperatures from 565 to 815 c depending on the water content of the inclusions homogenization of the vapor bubble occurs from 850 1160 c and complete melting of the silicate glass at about 950 c the highly variable proportions of the individual phases in the silicate melt salt h2o inclusions and the coexistence of silicate melt co2 inclusions indicates immiscibility during the crystallization of the magma primary and secondary co2 inclusions in the alkali syenite suite indicate lower densities from 0 10 to 0 22 g cm3 than those resulting from primary co2 inclusions in the gabbroic suite from 0 34 to 0 42 g cm3 the p t trajectory of the probable fluid evolution path shows that the crystallization of gabbro occurred between 1 and 1 4 kbars whereas alkali syenite crystallized between 200 and 400 bars the secondary h2o inclusions in alkali syenite were trapped in the later stages of the hydrothermal process and at much lower temperatures 130 290 c but at pressures relatively close to those of alkali syenite crystallization the almost isobaric conditions during the final stage of the fluid evolution path are explained by the very shallow emplacement of the alkali syenite intrusive body

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

grouping and migration of surface faulting and variations in slip rates on faults in the great basin province abstract nonuniformity of the occurrence of large slip events producing surface ruptures on seismogenic faults and variations in slip rate probably characterize seismogenic faulting in the great basin province western united states examples include the grouping of faulting events along the lost river fault idaho changes in tilt rates of the east range and cortez mountains nevada extension of slip along a fault on the northwest flank of the humboldt range nevada and migration or shifting of slip back and forth from one fault to another along subparallel range front faults in dixie valley nevada

dynamics of the magnitude frequency relation for foreshocks abstract time variations of the b value in the magnitude frequency law for strong foreshocks within days and hours before a mainshock were studied analysis of the world earthquake catalog 1964 1980 m 4 shows that b drops to half during a few hours before mainshocks an increase of b value with increase of the mainshock magnitude has not been detected

whole earth high resolution earthquake forecasts summary since 1977 we have developed statistical short and long term earthquake forecasts to predict earthquake rate per unit area time and magnitude the forecasts are based on smoothed maps of past seismicity and assume spatial and temporal clustering our new program forecasts earthquakes on a 0 1 grid for a global region 90n 90s latitude we use the pde catalogue that reports many smaller quakes m 5 0 for the long term forecast we test two types of smoothing kernels based on the power law and on the spherical fisher distribution the effective width of these kernels is much larger than the cell size thus the map discretization effects are insignificant we employ adaptive kernel smoothing which improves our forecast both in seismically quiet and active areas our forecasts can be tested within a relatively shorttime period since smaller events occur with greater frequency the forecast efficiency can be measured by likelihood scores expressed as the average probability gains per earthquake compared to spatially or temporally uniform poisson distribution another method uses the error diagram to display the forecasted point density and the point events our short term forecasts also assume temporal clustering described by a variant of omori s law like the long term forecast the short term version is expressed as a rate density in location magnitude and time any forecast with a given lower magnitude threshold can be recalculated using the tapered gutenberg richter relation to larger earthquakes with the maximum corner magnitude determined for appropriate tectonic zones

global seismicity of 2003 centroid moment tensor solutions for 1087 earthquakes abstract centroid moment tensor cmt solutions are presented for 1087 earthquakes that occurred during 2003 the solutions are obtained using the method of dziewonski et al dziewonski a m chou t a woodward j h 1981 determination of earthquake source parameters from waveform data for studies of global and regional seismicity j geophys res 86 2825 2852 and applying corrections for aspherical earth structure as represented by the whole mantle shear velocity model sh8 u4l8 of dziewonski and woodward dziewonski a m woodward r l 1992 acoustic imaging at the planetary scale in emert h harjes h p eds acoustical imaging vol 19 plenum press new york pp 785 797 the model of inelastic attenuation of durek and ekstrom durek j j ekstrom g 1996 a radial model of inelasticity consistent with long period surface wave attenuation bull seism soc am 86 144 158 is used to predict the decay of the waveforms the focal mechanisms of the largest or otherwise significant earthquakes of 2003 are reviewed

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

exsolution of immiscible vapor and liquid phases from a crystallizing silicate melt implications for chlorine and metal transport abstract the compositional variation of a cl bearing aqueous fluid exsolving from a crystallizing silicate melt is evaluated for the system haplogranitic melt na k c1 h 2 o with attention to the effect of vaporliquid immiscibility on the aqueous fluid above critical pressures for the aqueous fluid p 1 5 kb at 800 c where the fluid is single phase the cl concentration in the aqueous fluid c cl aq gradually decreases with crystallization of a silicate melt under rayleigh fractionation as demonstrated by previous studies however the variation of ca is quite different below critical pressures where vapor liquid immiscibility occurs in particular at low pressures p cl h 2 o ratio in a melt is small and ca will increase with crystallization a high cl h 2 o ratio at low pressure results in liquid exsolution and decreasing ca with crystallization eventually both vapor and liquid phases will exsolve simultaneously regardless of the initial exsolving phase during this simultaneous exsolution the composition of the exsolving vapor and liquid phases the mass ratio of these phases and the cl concentration of the silicate melt will all remain constant comparison of the model and published experimental data indicates that the simultaneous exsolution of vapor and liquid may occur from a normal rhyolite crystallized at pressures below the critical pressure for the aqueous fluid therefore simultaneous exsolution of the immiscible aqueous phases is likely to be a common phenomenon in magmatic hydrothermal systems at conditions for the vapor liquid immiscibility model calculations at 0 6 and 1 2 kb indicate that major amounts of cl in the system will be distributed to the liquid phase particularly at the lower pressure this suggests that the majority of chloridecomplexed metals exsolving from a magma may be transported in the liquid phase under shallow crustal conditions

patterns of seismic release in the southern california region southern california experiences earthquakes on the san andreas system of vertical right lateral predominantly strike slip faults and on a second system of faults that includes thrusts oblique slip left lateral and other faults pattern recognition and cluster analysis are used to analyze the catalog of earthquakes with magnitudes 5 5 from 1915 to 1994 we use pattern recognition to find a suite of traits that would characterize each of these two systems and distinguish them from each other both pattern recognition and cluster analysis show that epochs of seismic release occur in which one or the other system is the predominant form of earthquake activity for the past 2 decades the second system has been the active one small changes in the direction of plate movements could account for this phenomenon seismic release on the san andreas system is preceded by episodes of activity in the great basin or in the gulf of california presumably these episodes would represent extension in the former region and spreading and slip on transform faults in the latter

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

the b value as an earthquake precursor a systematic study of b values in new zealand has shown that within the vicinity of forthcoming large earthquakes there is initially an increase in b and then a return to normal the caracas and san fernando earthquakes show the same phenomenon which is related to that of seismic gaps

direct evolution of brine from a crystallizing silicic melt at the questa new mexico molybdenum deposit molybdenum mineralization in the southwest orebody at the questa deposit is associated with crystallization of aplite porphyry explosive brecciation and exsolution of magmatic hydrothermal fluids quartz k feldspar fluorophlogopite and molybdenite precipitated from exsolving aqueous fluids and cemented aplite porphyry and andesite wall rock clasts forming a magmatic hydrothermal breccia ore fluid inclusions in quartz in the breccia matrix trapped aqueous fluids that transported and precipitated molybdenum two fluid inclusion populations associated with molybdenite mineralization were identified the largest population commonly contains liquid vapor halite sylvite and one or more opaque daughter crystals these inclusions homogenize between 200 degrees and 500 degrees c and have a prominent mode at 360 degrees to 400 degrees c salinities vary from 31 to 57 wt percent nacl equiv low first ice melting temperatures suggest that additional fluid components possibly calcium or magnesium chlorides may be present approximately 80 percent of these inclusions homogenize by halite dissolution phase equilibria constraints require that these inclusions trapped fluids in the vapor absent field the remaining saline inclusions homogenize to liquid at temperatures above halite dissolution temperatures significantly the saline fluid did not coexist with a low density aqueous fluid a second population of inclusions contains fluids with salinities of 2 7 to 25 0 wt percent nacl equiv and homogenizes by vapor bubble disappearance vapor bubble expansion or critical behavior textural relationships and phase behavior during microthermometry indicate that these inclusions constitute a single population which formed as pressure and temperature fluctuated at near critical conditions pressure changes related to brecciation followed by crystallization and system resealing produced the observed fluids saline fluids were trapped as the system sealed following a major brecciation event these high salinity fluids were produced as the melt under pressure that increased from hydrostatic to lithostatic partitioned increasing amounts of chlorine into the exsolving aqueous fluid renewed fracturing and abrupt pressure decrease to hydrostatic conditions reduced the mass of chlorine partitioning to the exsolving fluid lower salinity fluids exsolved at near critical conditions and were trapped by inclusions that homogenize to liquid to vapor or by critical behavior the lack of cogenetic liquid and vapor rich fluid inclusions and phase equilibria constraints indicate that high salinity fluids or 57 wt nacl equiv were generated directly by the crystallizing magma and were not a product of aqueous fluid immiscibility

time series analysis of earthquake sequences by means of information recognizer abstract three seismic sequences of several thousand earthquakes each are analyzed by means of a tunable information recognizer known as wlzip these sequences are different both in the geographical coverage and the time span including earthquakes of magnitude larger than 8 0 the main variable under scrutiny here is the time interval between consecutive events two parameters mutability and interval dilation are defined for each sequence which relate to the information contained in it in this way it is possible to characterize different regimes in the seismic activity for instance mutability increases before large earthquakes and decreases sharply immediately after each of these events on the other hand interval dilation reaches a clear maximum several months before major earthquakes while it decreases to its lowest possible value after such earthquakes during the aftershock regime extensions of the application of this new method to other problems in seismicity are mentioned

temporal variations in seismicity during quasi static and dynamic rock failure abstract a comprehensive model is presented which can explain temporal fluctuations in seismic b values in the period leading to mechanical failure in terms of the underlying physical processes of time varying applied stress and stress corrosion enhanced crack growth under conditions of constant strain rate the form of the b value anomaly in the period leading to failure depends on the form of the stress time relationship for the case where dynamic failure occurs at peak stress after a period of strain hardening the model predicts a single cusp like b value anomaly reaching a critically low value of 0 5 at failure for the physically most realistic case where dynamic failure is preceded by a period of precursory strain energy release during strain softening the model predicts two minima in the b value separated by a temporary maximum or inflection point these fluctuations in the b value are consistent with reported intermediate term and short term earthquake precursors separated by a period of seismic quiescence for the case of quasi static cataclastic flow the b value mirrors the stress and never falls to the critical value because there is no critical rupture new results from a series of controlled laboratory experiments are presented in which microseismic event rates and b value were monitored contemporaneously with stress time data for all variants of the stress time relationship recent field observations of temporal changes in seismicity rates and b value preceding major earthquakes are also reported both data sets exhibit b value anomalies which are consistent with the model predictions

evidence for a global seismic moment release sequence temporal clustering of the larger earthquakes foreshock mainshock aftershock followed by relative quiescence stress shadow are characteristic of seismic cycles along plate boundaries a global seismic moment release history based on a little more than 100 years of instrumental earthquake data in an extended version of the catalog of pacheco and sykes 1992 illustrates similar behavior for earth as a whole although the largest earthquakes have occurred in the circum pacific region an analysis of moment release in the hemisphere antipodal to the pacific plate shows a very similar pattern monte carlo simulations confirm that the global temporal clustering of great shallow earthquakes during 1952 1964 at m 9 0 is highly significant 4 random probability as is the clustering of the events of m 8 6 0 2 random probability during 1950 1965 we have extended the pacheco and sykes 1992 catalog from 1989 through 2001 using harvard moment centroid data immediately after the 1950 1965 cluster significant quiescence at and above m 8 4 begins and continues until 2001 0 5 random probability in alternative catalogs derived by correcting for possible random errors in magnitude estimates in the extended pacheco sykes catalog the clustering of m 9 persists at a significant level these observations indicate that for great earthquakes earth behaves as a coherent seismotectonic system a very large scale mechanism for global earthquake triggering and or stress transfer is implied there are several candidates but so far only viscoelastic relaxation has been modeled on a global scale

immiscibility between silicate magmas and aqueous fluids a melt inclusion pursuit into the magmatic hydrothermal transition in the omsukchan granite ne russia abstract exsolution unmixing of the volatile element rich phases from cooling and crystallising silicate magmas is critical for element transport from the earth s interior into the atmosphere hydrosphere crustal hydrothermal systems and the formation of orthomagmatic ore deposits unmixing is an inherently fugitive phenomenon and melt inclusions droplets of melt trapped by minerals provide robust evidence of this process in this study melt inclusions in phenocrystic and miarolitic quartz were studied to better understand immiscibility in the final stages of cooling of and volatile exsolution from granitic magmas using the tin bearing omsukchan granite ne russia as an example primary magmatic inclusions in quartz phenocrysts demonstrate the coexistence of silicate melt and magma derived cl rich fluids brine and vapour and emulsions of these during crystallisation of the granite magma microthermometric experiments in conjunction with pixe and other analytical techniques disclose extreme heterogeneity in the composition of the non silicate phases even in fluid globules within the same silicate melt inclusion we suggest that the observed variability is a consequence of strong chemical heterogeneity in the residual silicate melt brine vapour system on a local scale owing to crystallisation immiscibility and failure of individual phases to re equilibrate the possible evolution of non silicate volatile magmatic phases into more typical hydrothermal chloride solutions was examined using inclusions in quartz from associated miarolitic cavities

can earth s rotation and tidal despinning drive plate tectonics abstract we re evaluate the possibility that earth s rotation contributes to plate tectonics on the basis of the following observations 1 plates move along a westerly polarized flow that forms an angle relative to the equator close to the revolution plane of the moon 2 plate boundaries are asymmetric being their geographic polarity the first order controlling parameter unlike recent analysis the slab dip is confirmed to be steeper along w directed subduction zones 3 the global seismicity depends on latitude and correlates with the decadal oscillations of the excess length of day lod 4 the earth s deceleration supplies energy to plate tectonics comparable to the computed budget dissipated by the deformation processes 5 the gutenberg richter law supports that the whole lithosphere is a self organized system in critical state i e a force is acting contemporaneously on all the plates and distributes the energy over the whole lithospheric shell a condition that can be satisfied by a force acting at the astronomical scale assuming an ultra low viscosity layer in the upper asthenosphere the horizontal component of the tidal oscillation and torque would be able to slowly shift the lithosphere relative to the mantle

extreme chemical heterogeneity of granite derived hydrothermal fluids an example from inclusions in a single crystal of miarolitic quartz magma derived fluids are important in geologic processes e g metal sequestration and ore deposition but are intrinsically transient samples of magmatic fluids represented by fluid inclusions in a single zoned quartz crystal from a miarolitic cavity within a porphyritic leucogranite hosting the industrialnoe tin deposit northeastern russia were studied by using modern in situ analytical methods laser raman spectroscopy proton induced x ray emission the fluid inclusions are either dominated by vapor or by complex multiphase brines the inclusions within a given trapping plane have similar phase relationships however there are significant variations between inclusions in different healed fractures phase and chemical compositions of individual brine inclusions demonstrate significant compositional heterogeneity in terms of absolute element concentrations and ratios of high temperature magmatic fluids accumulated in the miarolitic cavity this finding suggests that fluids leaving a crystallizing magma may have variable initial compositions that are subsequently modified by reactions with the rocks while the fluid is in transit to a miarolitic cavity as well as by processes in the cavity such as mixing crystallization and boiling the inferred chemical diversity and fractionation of granite derived fluids at near magmatic conditions imply that fluids entering a cooler hydrothermal system are extremely complex and their metallogenic signature may differ from that of related ore deposits

triggering of the 1999 mw 7 1 hector mine earthquake by aftershocks of the 1992 mw 7 3 landers earthquake 1 there is strong observational evidence that the 1999 mw 7 1 hector mine earthquake in the mojave desert california was triggered by the nearby 1992 mw 7 3 landers earthquake many authors have proposed that the landers earthquake directly stressed the hector mine fault our model of the landers aftershock sequence however suggests there is an 85 chance that the hector mine hypocenter was actually triggered by a chain of smaller earthquakes that was initiated by the landers main shock we perform our model simulations using the monte carlo method based on the gutenberg richter relationship omori s law bath s law and assumptions that all earthquakes including aftershocks are capable of producing aftershocks and that aftershocks produce their own aftershocks at the same rate that other earthquakes do in general our simulations show that if it has been more than several days since an m 7 main shock most new aftershocks will be the result of secondary triggering these secondary aftershocks are not physically constrained to occur where the original main shock increased stress this may explain the significant fraction of aftershocks that have been found to occur in main shock stress shadows in static coulomb stress triggering studies

global creepex distribution and its relation to earthquake source geometry and tectonic origin summary the ms mb ratio conventionally used for the discrimination of earthquakes and underground nuclear explosions has been studied for a pure earthquake catalogue in an attempt to classify earthquakes into two categories one related to extremely lowfrequency events of creep and the other to relatively high frequency explosions ms and mb measured at 20 s and 1 s respectively are considered as estimates of source spectra at two separate points thus allowing one to compare large samples of earthquakes from the spectral point of view creepex or the deviation of ms mfc points from the orthogonal regression of ms on mb is by definition a parameter independent of the size of seismic events it has been estimated from neic magnitudes and is studied in relation to parameters of central moment tensor solutions of the harvard group for this purpose the parameters of central moment tensors have been factorized to make classes of equivalence of events with the same dip and rake and arbitrary strike and size the resulting triangle representation of source mechanisms has been used to correct the global distribution of creepex for the type of source mechanism dip slip events have consistently lower creepex than strike slip ones however the global distribution of creepex either corrected or uncorrected for source mechanism has a clear tectonic pattern negative values in most of the subduction zones and positive ones in mid ocean ridges the dependence of creepex on focal depth is negligible according to empirical data for events shallower than 40 km limitation of the sample by considering only events in this depth range does not diminish considerably the amount of data and does not change the tectonic pattern of the creepex

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

premonitory transformation of steel fracturing and seismicity abstract transformation of microfracturing preceding the break up of steel and rock samples is similar to transformation of earthquakes flow prior to strong earthquakes in southern california the break up in a sample is preceded by transition from formation of new microcracks to coalescence or expansion of existing cracks this is reflected in the relation between the length and the number of the cracks similar transformation of seismicity precedes southern california earthquakes with magnitude m 6 6 1935 1994 specifically magnitude frequency relation bends downward for magnitudes from 3 to 4 5 and upward for magnitudes from about 4 5 to 6 in the usual notations the b value becomes larger in the first interval and smaller in the second one this transformation is accompanied by the increased share of aftershocks in the earthquakes flow in such a way the approach of a strong earthquake is reflected in both major traits of seismicity magnitude frequency relation and earthquake clustering imprecision of the earthquake catalog and reasonable variations in its analysis do not change our conclusions this phenomenon explains so far qualitatively a wide set of premonitory seismicity patterns we give it a formal definition allowing to test whether it takes place in other seismic regions