transport of pb and sr in leaky aquifers of the bufa del diente contact metamorphic aureole north east mexico the sr and pb isotopes from the 31 6 0 3 ma 2 old diente del bufa alkali syenite northeastern mexico and marbles of its contact aureole were used to trace the sources and the mobility of these metals during hydrothermal activity chert layers form aquifers within the marbles the marbles represent aquitards during fluid wallrock reaction the chert layers developed wollastonite rims early wollastonite rims have sr and pb isotopic compositions similar to those of their immediate host marbles which indicates that the isotopic composition of sr and pb is initially buffered by the marble later wollastonite and other replacement minerals rimming the aquifer have sr and pb isotopic compositions that carry with time increasingly larger contributions from the high salinity magmatic brine the sr and pb contributions from the alkali syenite can be traced isotopically for more than 90 m away from the contact of the intrusion in contrast sr and pb originating from the alkali syenite are traceable within the marbles only for 3 to 5 cm from the aquifer marble boundary this distance is comparable to the spatial distribution of isotopic alterations of c and o implying that sr and pb were transported into the marbles through a fluid phase the isotopic variation of sr pb c and o across the aquifer marble profiles reflects infiltration as a transport mechanism rather than diffusion because sr and pb are minor components in both the infiltrating fluid and the rock and because their concentrations are strongly affected by the distribution coefficients among the solid phases present there is little correlation between the isotopic compositions of the trace elements sr and pb and those of c and o which are major components in fluid and rock very thin meta argillite rinds at the outer margin of the aquifer represent residual material after the dissolution of calcite they are distinctly enriched in rb sr and u the rb and sr are to some extent residual from the original limestone mineralogy whereas u is dominantly derived from the magmatic fluid and leaked from the aquifer with the escaping immiscible co2 rich h2o co2 fluid that was produced by decarbonation the 238u 204pb values ranging from 100 to 250 and distinctly lowered th u in the meta argillite rims 1 demonstrate that u was transported with the magmatic fluid along the aquifer and 2 imply that during unmixing of the highly saline magmatic fluid u fractionated into the co2 rich h2o co2 fluid from which it precipitated selectively in the meta argillite band across the aquifer radioautographs demonstrate that the upper meta argillite rim has 20 to 40 times more u than the lower rim which implies that 20 to 40 times more co2 rich h2o co2 fluid has left through the upper aquifer contact

u pb isotopic dating of fluid infiltration and metasomatism during dalradian regional metamorphism in connemara western ireland a metasomatic diopside rock occurs at the top of the dolomitic connemara marble formation of western ireland and contains titanite and k feldspar in addition to around 90 diopside xmg 0 90 0 97 u pb isotopic measurements on this mineral assemblage show that the titanite is both unusually uranium rich and isotopically concordant with the result that a precise u pb age of 478 2 5 ma can be determined the age is identical within error to a less precise rb sr age of diopside k feldspar of 483 6 ma petrological evidence indicates that the assemblage crystallized at c 620 c close to or below the closure temperature of titanite the age thus provides a precise estimate of the time of metamorphism this age is 11 3 ma younger than the 490 ma age for nearby gabbroic plutons which has previously been used to constrain the peak metamorphic age this difference accords well with geological evidence that the gabbros were emplaced prior to the metamorphic peak analysis of minerals with high closure temperature from assemblages whose crystallization is unambiguously associated with a specific episode of fluid infiltration at the peak of metamorphism provides the basis for a new approach to dating metamorphism the success of this approach is demonstrated by the results from connemara

ionospheric electron enhancement preceding the 2011 tohoku oki earthquake 1 the 2011 march 11 tohoku oki earthquake mw9 0 caused vast damages to the country large events beneath dense observation networks could bring breakthroughs to seismology and geodynamics and here i report one such finding the japanese dense network of global positioning system gps detected clear precursory positive anomaly of ionospheric total electron content tec around the focal region it started 40 minutes before the earthquake and reached nearly ten percent of the background tec it lasted until atmospheric waves arrived at the ionosphere similar preseismic tec anomalies with amplitudes dependent on magnitudes were seen in the 2010 chile earthquake mw8 8 and possibly in the 2004 sumatra andaman mw9 2 and the 1994 hokkaido toho oki mw8 3 earthquakes but not in smaller earthquakes

variscan veins record of fluid circulation and variscan tectonothermal events in upper palaeozoic limestones of the moravian karst czech republic numerous variscan syntectonic calcite veins cross cut palaeozoic rocks in the moravian karst a structural petrographic and stable isotopic analysis of the calcite veins and a microthermometric study of fluid inclusions in these vein cements have been carried out to determine the origin of the variscan fluids and their migration during burial and deformation the isotopic parameters of white older more deformed and rose younger calcites are 87 sr 86 sr is between 0 7078 and 0 7082 white and 0 7086 rose 18 o is between 17 7 and 26 1 white and between 14 8 and 20 7 smow rose 13 c ranges from 0 1 to 2 5 white and from 0 3 to 1 6 v pdb rose the isotopic signatures point to precipitation in an older fluid system buffered by the host rock white calcites and to an open younger fluid dominated system rose calcites parent fluids h 2 o nacl system had salinities between 0 35 and 17 25 eq wt nacl the pressure corrected and confined homogenization temperatures suggest formation of the calcite veins from a fluid with a temperature between 120 and 170 c a pressure of 300 880 bar at a depth between 2 1 and 3 2 km the fluids were most likely confined to a particular sedimentary bed as a bed scale fluid migration white older calcite veins or later to a pile of palaeozoic sediments as a stratigraphically restricted fluid flow rose younger calcite veins the low temperatures and pressures during precipitation of calcites which took place close to a peak of burial deformation confirm the distal position of the moravian karst region within the variscan orogen

vapour loss boiling as a mechanism for fluid evolution in metamorphic rocks the calculation of fluid evolution paths during reaction progress is considered for multicomponent systems and the results applied to the ternary system co2 h2o nacl fluid evolution paths are considered for systems in which a co2 rich phase of lesser density vapour is preferentially removed from the system leaving behind a saline aqueous phase liquid such boiling leads to enrichment of the residual aqueous phase in dissolved components and for certain reaction stoichiometries to eventual saturation of the fluids in salt components distinctive textures particularly radiating growths of prismatic minerals such as tremolite or diopside are associated with saline fluid inclusions and solid syngenetic salt inclusions at a number of field localities the most thoroughly studied of these localities is campolungo switzerland where metasomatic rocks have developed in association with fractures and veins at 500 c and 2 000 bars of pressure the petrography of these rocks suggests that fluid phase separation into liquid and vapour has been an important process during metasomatism fracture systems with fluids at pressure less than lithostatic may facilitate the loss of the less dense vapour phase to conditions of the amphibolite facies

m w dependence of the preseismic ionospheric electron enhancements ionospheric electron enhancement was reported to have occurred 40 min before the 2011 tohoku oki mw9 0 earthquake japan by observing total electron content tec with global navigation satellite systems receivers their reality has been repeatedly questioned due mainly to the ambiguity in the derivation of the reference tec curves from which anomalies are defined here we propose a numerical approach based on akaike s information criterion to detect positive breaks sudden increase of tec rate in the vertical tec time series without using reference curves we demonstrate that such breaks are detected 25 80 min before the eight recent large earthquakes with moment magnitudes mw of 8 2 9 2 the amounts of precursory rate changes were found to depend upon background tec as well as mw the precursor times also showed mw dependence and the precursors of intraplate earthquakes tend to start earlier than interplate earthquakes we also performed the same analyses during periods without earthquakes to evaluate the usefulness of tec observations for short term earthquake prediction

gps detection of ionospheric perturbations following the january 17 1994 northridge earthquake sources such as atmospheric or buried explosions and shallow earthquakes producing strong vertical ground displacements are known to produce pressure waves that propagate at infrasonic speeds in the atmosphere at ionospheric altitudes low frequency acoustic waves are coupled to ionospheric gravity waves and induce variations in the ionospheric electron density using global positioning system gps data recorded by the permanent gps network operating in southern california we computed ionospheric electron content time series for several days preceding and following the january 17 1994 mw 6 7 northridge earthquake we observe an anomalous signal beginning several minutes after the earthquake with time delays that increase with distance from the epicenter the signal frequency and phase velocity are consistent with results from numerical models of atmospheric ionospheric acoustic gravity waves excited by seismic sources as well as previous electromagnetic sounding results we believe that these perturbations are caused by the ionospheric response to the strong ground displacement associated with the northridge earthquake

the control of cathodoluminescence in dolomite by iron and manganese variations in the cathodoluminescent properties of carbonates are usually attributed to differing proportions of manganese mn2 as the most important activator and iron fe2 as the main inhibitor of luminescence interactions between manganese and iron concentrations and the luminescent properties of dolomite are demonstrated by petrographic and chemical analyses of 86 samples of dolomite representing a range of depositional environments and ages cambrian to cretaceous and a wide geographical distribution north america and europe iron and manganese are positively correlated in the dolomites with the former showing a greater range of variation very small amounts of manganese are sufficient to activate the luminescence and as little as 100 ppm mn2 is present in highly luminescing samples the intensity of luminescence is not proportional to the manganese concentration iron begins to quench luminescence as its concentration reaches 10 000 ppm above that level luminescence is rapidly lost and total extinction occurs among samples containing more than 15 000 ppm fe2 regardless of the manganese concentration

high resolution mapping of tec perturbations with the gsi gps network over japan two dimensional total electron content tec perturbations over japan are mapped with the geographical survey institute gsi gps network geonet gps earth observation network its spatial resolution is 0 15 latitude 0 15 longitude and temporal resolution is 30 seconds two dimensional tec observations with these high resolutions revealed spatial structures and temporal evolutions of traveling ionospheric disturbances tids in the nighttime mid latitude ionosphere on july 03 1997 a preliminary result of the tec perturbation mapping indicates that it would be a strong tool to investigate the ionospheric structures in detail coordinated observations with other ionospheric observation techniques such as incoherent scatter is radars airglow imagers and ionosondes are needed to clarify the vertical structure of the ionosphere

elemental dispersion and stable isotope fractionation during reactive fluid flow and fluid immiscibility in the bufa del diente aureole ne mexico evidence from radiographies and li b sr nd and pb isotope systematics the 31 6 0 3 ma old bufa del diente alkali syenite ne mexico intruded a sequence of cretaceous limestones with intercalated sub horizontal chert layers the cherts acted as aquifers that facilitated transport of brines and pegmatitic melts within the shallow level 1 kbar contact metamorphic aureole fluid driven reactions between chert and marble wallrock and the influx of late melts and various fluids gave rise to distinct chemical and isotopic signatures within the aquifer and across the zones of infiltration and fluid driven reaction aqueous brines of magmatic origin produced thick wollastonite mantles around the chert layers wollastonite formation occurred at the expense of limestone and chert and generated co2 this co2 induced fluid unmixing into an aqueous brine and a low density co2 rich fluid which was lost to the overlying marble where it oxidized organic matter and caused 13c and 18o shifts in a zone some 5 10 cm wide after wollastonite formation the chert aquifers were locally intruded by pegmatite veins carrying alkali feldspar quartz aegirine augite eudialyte zircon and apatite aqueous fluids that exsolved during crystallization of the pegmatite veins escaped along late cross fractures and migrated along the inner and outer borders of the wollastonite margins chemical dispersion patterns of u al na k p s fe and ree across the chert to marble boundary and its metasomatic rims are shown by autoradiography and neutron induced radiography scavenging of cations at mineralogical contacts and cation transport into the marbles occurred only on the mm to cm scale isotopic data for pb and sr across a simple metachert marble boundary and for pb sr nd b and li across a metachert pegmatite marble sequence demonstrate the following 1 the pb and sr isotopic signature of early fluids was buffered by the carbonate wallrock only late fluids shielded from wallrock interaction by a wollastonite mantle variably preserved a memory of their initial magmatic signature 2 since the nd isotope signature of marble and chert is bound to calcite and clay minerals systematic shifts to unradiogenic nd in marble reflect loss of carbonate bound nd as the wollastonite margin is approached nd in the wollastonite margin is dominated by nd originally bound to clay minerals the later emplacement of the pegmatite which carried the nd isotope signature of its alkali syenite source had little effect on the nd isotopic composition of the wollastonite rim 3 although the li and b isotopic compositions reflect the alkali syenite source they are also affected by isotopic fractionation and partitioning between melt fluid and solids

decorative marbles from the krkonose jizera terrane bohemian massif czech republic provenance criteria marbles from western part of the krkonose jizera terrane northern part of the bohemian massif have been studied to obtain mineropetrographic and chemical reference data for provenance studies samples from six different quarries were analysed by mineralogical petrographic and geochemical methods optical microscopy x ray diffraction stable isotope ratio analysis cathodoluminescence bulk magnetic susceptibility petrographic characteristics permit a distinction between fine grained to medium grained marbles from the jizera mts amphibolite metamorphic facies and fine grained marbles from the jest d mts low grade greenschist facies the samples studied are mainly calcitic with the exception of those from raspenava in which dolomite is abundant in two types the mineralogical composition of the insoluble residues is clinochlore serpentine tremolite diopside pyrite magnetite in case of the locality raspenava and clinochlore muscovite quartz pyrite rutile haematite in case of the localities from the jest d mts 13c and 18o variations in primary and secondary carbonate phases allow to distinguish genetically different carbonate veins and permit quarry separation in one case raspenava jizera mts the 13c and 18o values of the groundmass range from 1 to 3 and from 8 to 20 pdb respectively the 13c and 18o values of secondary carbonate veins decrease to 3 and reach more negative values up to 26 in case of 18o the fabric of cathodomicrofacies allows the distinction between calcite and dolomite except three localities pilinkov horni hanychov jitrava rose type with majority of quenchers high content of iron in carbonate the genetically different calcite is characterised by a pale and dark orange luminescence distribution serpentine tremolite forsterite opaque minerals and quartz have no luminescence and very dull luminescence respectively the majority of studied marbles exhibits low values of the bulk magnetic susceptibility with the exception of those from raspenava rich in magnetite

preseismic ionospheric anomalies detected before the 2016 kumamoto earthquake on 15 april 2016 the kumamoto earthquake mw 7 3 occurred in japan with no warning signals global navigation satellite system gnss receivers provide useful information on disturbances in the ionosphere by calculating the changes in total electron content tec which is the number of electrons in the ionosphere here we show our recently proposed correlation analysis of tec data which can detect the preseismic ionospheric anomalies from the public gnss data our method detected the ionospheric anomaly several tens of minutes before the 2016 kumamoto earthquake near its epicenter furthermore we gave an indicator to distinguish between the preseismic tec anomalies and the medium scale traveling ionospheric disturbances mstids by calculating the anomalous area rates these results support the hypothesis for existence of the preceding phenomena before large earthquakes

coseismic ionospheric disturbance of the large strike slip earthquakes in north sumatra in 2012 mw dependence of the disturbance amplitudes we studied ionospheric responses to the 2012 april 11 mw8 6 north sumatra earthquake using total electron content tec measurements with the regional global navigation satellite system gnss network this earthquake ruptured the oceanic lithosphere off the indian ocean coast of north sumatra and is known as the largest strike slip earthquake ever recorded coseismic ionospheric disturbances cid with rapid tec enhancement of a few tec units propagated northward with a speed of acoustic waves 1 km s resonant atmospheric oscillation with a frequency 4 mhz have been found as monochromatic oscillation of tec lasting for an hour after the main shock and the largest aftershock we compared cid amplitudes of 21 earthquakes worldwide with moment magnitudes mw 6 6 9 2 they roughly obeyed a law such that cid amplitude increases by two orders of magnitude for the mw increase of three the 2012 north sumatra earthquakes slightly deviated negatively from the trend possibly reflecting their strike slip mechanisms i e small vertical crustal movements for their magnitudes

preseismic ionospheric electron enhancements revisited 1 possible enhancement of ionospheric total electron content tec immediately before the 2011 tohoku oki earthquake mw9 0 has been reported by heki 2011 critical responses to it often come in two stages they first doubt the enhancement itself and attribute it to an artifact second when they accept the enhancement they doubt the significance of the enhancement among natural variability of space weather origin for example kamogawa and kakinami 2013 attributed the enhancement to an artifact falsely detected by the combined effect of the highly variable tec under active geomagnetic condition and the occurrence of a tsunamigenic ionospheric hole here we closely examine the time series of vertical tec before and after the 2011 tohoku oki earthquake we first demonstrate that the tsunami did not make an ionospheric hole and next confirm the reality of the enhancement using data of two other sensors ionosonde and magnetometers the amplitude of the preseismic tec enhancement is within the natural variability and its snapshot resembles to large scale traveling ionospheric disturbances however distinction could be made by examining their propagation properties similar tec anomalies occurred before all the m 8 5 earthquakes in this century suggesting their seismic origin

channelled fluid infiltration and variation in permeability in reynolds range marbles australia strike parallel flow of h 2 o rich fluids through reynolds range marbles formed wollastonite bearing assemblages wollastonite abundance varies on a millimetre de from 10 to 66 modal the mineralogy of unmetasomatized marbles suggests that the formation of more than c 19 wollastonite requires silica metasomatism comparison with advective transport models suggests that the variable wollastonite contents may be explained by time integrated fluid fluxes and intrinsic permeability varying by up to two orders of magnitude on a millimetre scale fluids were probably focused through the marble within microfractures and the variations in intrinsic permeability may reflect variable fracture density

ionosphere plasma bubbles and density variations induced by pre earthquake rock currents and associated surface charges 1 recent ionospheric observations indicate that the total electron content tec may anomalously decrease or increase up to 5 20 before the occurrence of big earthquakes the ionospheric density variations can be caused by earth surface charges currents produced from electric currents associated with the stressed rock we formulate a coupling model for the stressed rock earth surface charges atmosphere ionosphere system the stressed rock acts as the dynamo to provide the currents for the coupling system the electric fields and currents in the atmosphere and the lower boundary of ionosphere are obtained by solving the current continuity equation j 0 where j is the current density a three dimensional ionosphere simulation code is then used to study the ionospheric dynamics based on the obtained electric fields and currents the simulation results show that a current density jrock 0 2 10 a m2 in an earthquake fault zone is required to cause daytime tec variations of 2 25 the simulation results also show that a current density jrock 0 01 1 a m2 can lead to nighttime tec variations of 1 30 as well as the formation of a nighttime plasma bubble equatorial spread f extending over the whole magnetic flux tube containing the earthquake epicenter we suggest that observations of daytime and nighttime tec variations and a nighttime plasma bubble within the affected region can be used as precursors for earthquake prediction

ground water radon anomaly before the kobe earthquake in japan radon concentration in ground water increased for several months before the 1995 southern hyogo prefecture kobe earthquake on 17 january 1995 from late october 1994 the beginning of the observation to the end of december 1994 radon concentration increased about fourfold on 8 january 9 days before the earthquake the radon concentration reached a peak of more than 10 times that at the beginning of the observation before starting to decrease these radon changes are likely to be precursory phenomena of the disastrous earthquake

groundwater potentiality index a strategically conceived tool for water research in fractured aquifers durable development requires full profit and knowledge of natural resources potentialities multi criterion approaches that encompass geological morphological hydrological and geographical information system technologies are ones of exiting developments in environmental sciences this work is a proposition of a numerical model based on a groundwater potentiality index gpi calculation using data on rock fracturing lithology drainage topography rainfall and drilling water yield it provides the ability to identify areas indicating favorable conditions for exploratory well positioning in semi arid zones with non permeable outcrops it is therefore a helpful tool to assist water resources prospecting in deprived regions the newly conceived approach has been applied in the southeastern boundary of the bouregreg and coastal basins of central morocco where paleozoic fractured rocks outcrop the suitability of the gpi method use was verified by comparing the gpi map values with water yield of thirteen pumping tests in a field checking area which revealed promising results

lithosphere atmosphere ionosphere coupling laic model an unified concept for earthquake precursors validation abstract the paper presents a conception of complex multidisciplinary approach to the problem of clarification the nature of short term earthquake precursors observed in atmosphere atmospheric electricity and in ionosphere and magnetosphere our approach is based on the most fundamental principles of tectonics giving understanding that earthquake is an ultimate result of relative movement of tectonic plates and blocks of different sizes different kind of gases methane helium hydrogen and carbon dioxide leaking from the crust can serve as carrier gases for radon including underwater seismically active faults radon action on atmospheric gases is similar to the cosmic rays effects in upper layers of atmosphere it is the air ionization and formation by ions the nucleus of water condensation condensation of water vapor is accompanied by the latent heat exhalation is the main cause for observing atmospheric thermal anomalies formation of large ion clusters changes the conductivity of boundary layer of atmosphere and parameters of the global electric circuit over the active tectonic faults variations of atmospheric electricity are the main source of ionospheric anomalies over seismically active areas lithosphere atmosphere ionosphere coupling laic model can explain most of these events as a synergy between different ground surface atmosphere and ionosphere processes and anomalous variations which are usually named as short term earthquake precursors a newly developed approach of interdisciplinary space terrestrial framework istf can provide also a verification of these precursory processes in seismically active regions the main outcome of this paper is the unified concept for systematic validation of different types of earthquake precursors united by physical basis in one common theory

seismo ionospheric signatures prior to m 6 0 taiwan earthquakes this paper examines variations of the greatest plasma frequency in the ionosphere fof2 recorded by the chung li ionosonde 25 0 n 121 1 e before m 6 0 earthquakes during 1994 1999 the 15 day running median and the associated inter quartile range are utilized as the reference and the upper or lower bounds to monitor the ionospheric fof2 variations for finding seismo ionospheric signatures precursors of the earthquakes it is found that precursors in the form of the recorded fof2 falling below its associated lower bound around 1200 1700 lt appear 1 6 days prior to these earthquakes on september 20 1999 ut september 21 taiwan local time a large mw 7 7 earthquake struck central taiwan near the small town of chi chi we analyzed the fof2 and found three clear precursors 1 3 and 4 days prior to the chi chi earthquake

global positioning system detection and energy estimation of the ionospheric wave caused by the 13 july 2003 explosion of the soufriere hills volcano montserrat 1 volcanic explosions or shallow earthquakes are known to trigger acoustic and gravity waves that propagate in the atmosphere at infrasonic speeds at ionospheric heights coupling between neutral particles and free electrons induces variations of electron density detectable with dual frequency global positioning system gps measurements using gps data collected in the caribbean we identified an ionospheric perturbation after a major volcanic explosion at the soufriere hills volcano montserrat lesser antilles on 13 july 2003 spectral analysis reveals peaks centered at 1 and 4 mhz similar to those in previous observations and consistent with theory suggesting both gravity and acoustic wave components we retrieve a horizontal velocity of 624 m s for the acoustic component which implies upward propagation at 33 consistent with ray tracing results we model the acoustic wave using an n wave pressure source at ground level combined with ray tracing to propagate the neutral pressure wave this accounts for the dispersive characteristics of the atmosphere while conserving total acoustic energy plasma velocity is derived from neutral velocity using a finite difference solution of the magnetohydrodynamic momentum equation the continuity equation for charge densities is used to compute corresponding electron density variations which are then numerically integrated along satellite to receiver line of sights simultaneously accounting for the satellite displacements we minimize the misfit between observed and model waveforms to estimate a total acoustic energy release of 1 53 x 10 10 j for the primary explosion event at soufriere hills volcano associated with the peak dome collapse this method can be applied to any explosion of sufficient magnitude provided gps data are available at near to medium range from the source

reduction of electron temperature in low latitude ionosphere at 600 km before and after large earthquakes 1 we examine ionospheric electron temperatures te observed by hinotori satellite during three earthquakes m6 6 occurred in november 1981 m7 4 and m6 6 in january 1982 over philippine respectively it is found that t e around the epicenters significantly decreases in the afternoon periods within 5 days before and after the three earthquakes the region of ionosphere disturbance extends to 80 120 degrees in longitude a tendency exists that duration of the disturbance becomes longer as the increase of earthquake magnitude f 2 peak frequency f o f 2 and virtual height h f from a chain of 4 ionosonde stations located in the longitude zone of 120 e 130 e are used together with electron density n e that is observed simultaneously onboard hinotori satellite to find possible cause mechanisms of the abnormal reduction of electron temperatures behavior of hinotori t e n e and ionosonde f o f 2 h f implies the existence of westward electric field over epicentre our finding suggests that simple two plasma instruments might be able to play a fundamental role to study ionosphere disturbance associated with earthquake if the constellation of small mini satellites is organized and the orbits are properly chosen

first ionospheric images of the seismic fault slip on the example of the tohoku oki earthquake 1 1hz gps measurements from the japanese gps network geonet allowed to retrieve information on the seismic fault of the great m9 0 tohoku oki earthquake from the ionosphere total electron content tec measurements the first arrival of the tec perturbation was registered 464 seconds after the earthquake 140 km on the east from the epicenter within next 45 seconds the distribution of ionospheric points imaged a rectangular area 37 39 39 28 n 142 8 143 73 e which coincides with the area of the coseismic crustal uplift from this source region the coseismic ionospheric perturbation further propagated at 1 3 1 5 km s such velocity values are 30 40 higher than previously reported for acoustic waves it is likely that we observed shock acoustic waves propagating at supersonic speed and having blown all the electrons available between the ground and the height of detection this fact is coherent with registration of the first arrival of perturbation 464 sec after the earthquake that is generally speaking too short time for a regular acoustic wave to reach the ionosphere our findings show that the real time gps monitoring of seismo active areas could inform about the parameters of coseismic crustal displacements and can be subsequently used for short term tsunami warnings in the case of the 03 11 2011 earthquake the first ionosphere perturbations were registered 17 minutes before the tsunami arrived on the east coast of honshu

immiscible fluids in metamorphism implications of two phase flow for reaction history fluid immiscibility between a co 2 rich fluid and brine has been described from several medium to high grade marbles and calcsilicates here we also report evidence for ch 4 h 2 o immiscibility in low grade metamorphic rocks from wales and suggest that the flow of such immiscible fluids may be comparable to that of water oil or water gas mixtures in petroleum reservoirs this analogy implies that where one fluid is being produced by reaction it will flow out of the rock while the other remains immobile except insofar as it is soluble in the more abundant fluid phase hence extensive reaction may take place in the presence of coexisting immiscible fluids each having high activities it is proposed that this type of flow behavior not only accounts for the development of salt saturated fluids in marbles but also may be responsible for the elimination of carbonate and extensive loss of graphite from pelites in the lower part of the greenschist facies

is an ionospheric electron enhancement preceding the 2011 tohoku oki earthquake a precursor 1 heki 2011 reported that the tec gradually enhanced from 40 minutes before the 2011 m9 0 off the pacific coast of tohoku earthquake tohoku eq to the time when the co seismic acoustic wave reached the ionosphere and the tec immediately recovered at the normal state this paper shows an alternative interpretation of total electron content tec variation in the ionosphere associated with the tohoku eq our interpretation is that a tsunamigenic ionospheric hole a wide depletion of the tec occurred after the co seismic acoustic wave reached the ionosphere and gradually recovered at the normal state with several tens of minutes kakinami et al 2012 the difference between heki 2011 and kakinami et al 2012 is attributed to the reference curves of the tec to extract the ionospheric variations the former is given by the least squares fitting curve of the eq day data excluding an expected precursor period while the latter is given by the data of the similar orbit of global positioning system gps satellite on another day the results suggest that variation of slant tec is explained by the depletion of tec due to tsunami rather than the precursory enhancement

an application of cathodoluminescence microscopy to the study of textures and reactions in high grade marbles from connemara ireland upper amphibolite facies dolomite and calcite marbles from the dalradian connemara marble formation of western ireland display a wide range of textures when viewed in cathodoluminescence that are invisible in transmitted light examples observed include growth zones in calcite that appear to represent the infilling of a metamorphic secondary porosity produced by the large reduction in solid volume accompanying growth of tremolite from dolomite and quartz retrograde phenomena are widespread and include both carbonate pseudomorphs after tremolite and coarse veining which is in optical continuity with peak metamorphic calcite but otherwise indistinguishable from it admixture of such widely differing calcite types may account for scatter in some stable isotope studies of marbles

fluid immiscibility in metamorphic rocks evidence of fluid immiscibility in metamorphic rocks comes in the best of all worlds from fluid inclusion observations in fact fluid immiscibility should be anticipated over the full range of metamorphic conditions provided that appropriate bulk fluid compositions are present in a review paper entitled metamorphic fluids the evidence from fluid inclusions crawford and hollister 1986 summarized the role of fluid immiscibility in metamorphism was only recognized after serious study of fluid inclusions in metamorphic rocks was underway in the late 1970s and has yet to attract the attention of more than a handful of petrologists studying metamorphic rocks since then tremendous progress has been made a huge amount of fluid inclusion studies have convincingly shown that immiscible fluids can be present in rocks of all bulk compositions and at all p t conditions thermodynamic databases of minerals solid solutions and fluid mixtures along with the development of gibbs free energy minimization programs now allow for detailed prediction of the evolution of phase assemblages and mineral compositions in p t space significant progress has also been made in understanding reaction kinetics diffusional and convective mass transport and the interpretation of fluid rock interaction during metamorphism given the vast fluid inclusion evidence of immiscibility it would appear however that phase petrology and mass transport in any specific rock where fluids are involved are not correctly interpreted if possible or proven immiscibility is not considered relatively few studies directly link mineral reactions with immiscible fluids therefore this review aims at working out the effects of fluid immiscibility on the progress of metamorphic reactions and fluid transport over a wide range of conditions questions arise directly from the fluid inclusion record in metamorphic rocks this chapter however is organized the other way round at first it summarizes phase relations of fluid systems pertinent to

explosion energy of the 2004 eruption of the asama volcano central japan inferred from ionospheric disturbances 1 the japanese dense array of global positioning system recorded ionospheric disturbances as changes in total electron content 12 minutes after the september 1 2004 eruption of the asama volcano central japan the disturbance had a period of one and a quarter minutes and propagated as fast as 1 1 km s suggesting its origin as the acoustic wave generated by the explosion by comparing the disturbance amplitudes with those by a surface mine blast with a known energy the overall asama explosion energy is inferred to be about 2 1014 j

evidence for a regional scale fluid loss event during mid crustal metamorphism how fluid is released from the deep crust during metamorphism remains controversial whereas some authors advocate large scale fluid fluxes due to convective circulation of metamorphic fluid1 others consider that only one way flow is possible2 3 furthermore some flow models imply that fluid moves across and largely independently of sedimentary layering1 2 whereas many fluid based studies find evidence for focusing of flow by particular lithologies2 4 7 here we report a study of metamorphic fluid flow on a regional rather than an outcrop scale using a combination of field geology petrology and theoretical and isotope geochemistry we identify metasomatic lithologies at the top of a dolomitic marble unit which must have drawn in water over a kilometre scale from adjacent pelitic formations we suggest that this flow was part of a single major fluid loss event near the metamorphic peak fluid followed the metasomatic layers to structural highs where it broke out into adjacent schists to form skarns this fluid loss may have changed the rheology of the rock involved and terminated regional folding