a study on wind driven circulation in the subarctic north pacific using topex poseidon altimeter data time dependent wind driven circulation in the subarctic region in the north pacific is investigated by using topex poseidon t p altimeter data and european centre for medium range weather forecasts ecmwf wind data for about 2 years the first empirical orthogonal function eof of the sea level anomaly sla without the variation related to the steric height change sla represents a basin sized oscillation which is associated with the spin up and spin down of the subarctic gyre moreover the time series of the first eof corresponds to the oyashio current variation measured by the moored current meter at about 1250 m depth the first and third eofs of the wind stress curl fields represent basin sized south north oscillations being associated with changes in intensity and the latitudinal position of the aleutian low time series of both the dominant eofs of the sla and the wind stress curl anomaly are correlated well which suggests that dominant variation of the sla is mainly controlled by the wind stress curl fields represented by the first and third eofs the time series of the first eof of the sla is in agreement with that of sverdrup transport estimated by the wind stress curl near 40 n with a correlation of 0 70 both standard deviations of the t p sla derived transports in the interior and the western boundary regions are consistent with that of the sverdrup transport in the same order of magnitude these results suggest that sea surface height variation in the subarctic north pacific is approximately explained by the time dependent wind driven circulation

climatic fluctuations reflected in the evolution of fluvial systems of central eastern europe 60 8 ka cal bp abstract in general the evolution of fluvial systems in central eastern europe reflects the main phases of climatic changes during the period of 60 8 ka cal bp registered in greenland ice cores and their isotopic 18 o curves the greenland isotope curve shows many more wiggles and stages than the fluvial record of the same time especially during the interpleniglacial phase in central eastern europe we observe several deviations from those climatic trends connected with different factors among which are the long distance of the region from the atlantic ocean and an increase in continentality at times this region was occupied by permafrost although the coexisting warm summers during a part of the studied period enabled the presence of a forest cover these factors together controlled the specific features of the fluvial regime and sediment load reflected in alternating trends to erosion or aggradation and from meandering to braiding the permafrost influenced snowmelt floods and tendency to braiding the dense vegetation with trees reduced the supply of sediments and stabilized the meandering channels very distinct changes occurred in the river valleys that drain the mountains where ceaseless fluctuations of vegetation vertical zones were present especially during the unstable interpleniglacial when the supply of load from the higher vegetation zones was increased this system controlled by the climate and plant vegetation was modified by other factors including tectonics wind activity during dry periods blocking of valleys by ice sheets meltwater supply and sea level fluctuations of two reservoirs

a new automatic subsurface gas monitoring system for seismogeochemical studies installed in haruno borehole shizuoka prefecture central japan the results of subsurface gas monitoring by application of gas chromatography gc to the gas composition of bubbles associated with groundwater for seismogeochemical studies are reported an automated gas monitoring system was used to determine gas compositions in a 500 m borehole at the haruno crustal movement observation site hos central japan during period 1 from december 1999 to december 2000 the average two standard deviation 2sd compositions of gases in this period were he 82 29 ppmv h2 170 62 ppmv ar 0 05 0 07 n2 50 8 and ch4 45 6 a new automated gas monitoring system equipped with a micro gc was installed in the borehole at the hos and gas bubbles from the borehole were monitored during period 2 from december 2006 to march 2007 the average two standard deviation 2sd compositions of gases in this period were he 8 7 ppmv h2 13 15 ppmv ar 0 6 0 3 n2 66 7 and ch4 14 14 the gas concentration ratios he ar h2 ar n2 ar and ch4 ar fluctuated significantly over time and repeatedly showed abrupt spike like increases during period 2 the gas compositions obtained in period 1 and 2 were markedly different over the period from 2006 to 2007 the gas bubbles were depleted in he h2 and ch4 of deep origin but enriched in ar and n2 of atmospheric origin this difference can be interpreted as being due to an irreversible change of the aquifer gas system the present deep component in the hos gas is estimated to have composition he 63 ppmv h2 37 ppmv ar 0 17 n2 63 and ch4 37 the new monitoring system is able to analyze the gas composition using a smaller volume of sample gas and with greater precision than the previous system during the 3 month monitoring period 2 the separation capacity of the capillary column of the micro gc was sufficiently maintained to determine gas chromatographic peak areas for the five gaseous species examined this study confirms that the new monitoring system with micro gc is promising for continuous subsurface gas monitoring for earthquake prediction studies

h2 generation in wet grinding of granite and single crystal powders and implications for h2 concentration on active faults 1 granite and single crystals of quartz alkali feldspar biotite and muscovite are ground in ph controlled and pure water solutions using a ball mill at ambient condition to examine the production of h2 the amount of h2 generated by grinding is linearly related with the surface area of ground samples the slope of the straight line indicates h2 productivity of each mineral 3 9 10 3 mol m2 quartz 1 0 10 3 mol m2 alkali feldspar 3 6 10 2 mol m2 biotite 2 2 10 2 mol m2 muscovite 4 5 10 3 mol m2 granite high productivity of biotite and muscovite is probably related to the existence of hydroxyls in their crystal structures interestingly h2 production did not depend on the ph of the solution in the case of biotite and granite while comparisons between fluid acidity and h2 concentration on several active faults suggest that anomalously high h2 is commonly observed at relatively acidic water springs this correlation may be explained by locally high abundance of phyllosilicates

preseismic hydrogen gas anomalies caused by stress corrosion process preceding earthquakes simultaneous monitoring of he h2 ar n2 ch4 and rn in gas bubbles of groundwater from the 1 500 m deep nagashima well in the active yoro fault zone central japan reveals that three microearthquakes with m 1 6 2 6 in the fault zone are accompanied and preceded by increases of h2 as is a moderately large event with m 5 4 in the same fault zone all the focal distances of the earthquakes are within 25 km no comparable anomalies were seen in the gas species other than h2 we suggest that the selective and preseimic increases of h2 in groundwater gas bubbles are geochemical signals of the earthquake nucleation process of stress corrosion mechanism aseismic slips preceding earthquakes in the active fault zone are likely to have enhanced h2 production by mechanochemical reaction of fractured rock surface with water in pre existing fault planes as groundwater conduits

relationships between gas geochemistry and release rates and the geomechanical state of igneous rock massifs in contrast to sedimentary sequences the relationships between the stressed state of igneous rocks and the chemistry and physical properties of gases contained within them are not well known here we attempt to fill this gap by using as an example the apatite nepheline and rare metal ore deposits hosted within the khibiny and lovozero alkaline nepheline syenite complexes of the kola peninsula nw russia these massifs are characterized by unusually high for igneous rocks contents of multi component essentially hydrogen hydrocarbon gases and also by high hardness elasticity and unevenly distributed subhorizontal tectonic stresses relationships between the chemical and dynamic characteristics of the gases and the geomechanical properties of the host rocks have been examined using field observations and laboratory experiments patterns of gas release variations in time and space gas emissions from rock pillars during artificial loading variations of gas pressure in sealed shot holes and changes in liberation rates of gaseous components during experimental rock loading are suggested to result from changes in rock stress and deformation state gas compositions in sealed shot holes in stressed rocks change with time partly this is due to belated release of gases held in fluid inclusions and isolated voids and their subsequent mixing with gases held in interconnected fracture systems as the included gases are preferentially released as fluid inclusion arrays are opened during later stages of stress build up partly it may also be because released gases may react with new fracture surfaces to generate enhanced levels of reduced h2 gases

lower and middle pleistocene human settlements recorded in fluvial deposits of the middle loire river basin centre region france abstract this paper records the findings from c 80 prehistoric sites that have been discovered in the alluvial deposits of the rivers creuse cher and loir tributaries of the middle loire river over the period since 1981 these deposits comprise river terrace aggradations formed during successive glacial interglacial cycles which have recorded climate and environment during quaternary time the systematic dating of these river deposits by electron spin resonance esr applied to optically bleached sedimentary quartz has resulted in the establishment of a chronological framework for the evolution of these rivers during lower and middle pleistocene between 1 7 ma and 130 ka evidence for early palaeolithic mode 1 industries with an in situ context workshops soils in the highest aggradations indicates that hominins were present in the study area near the geographical centre of france 47 n around 1 1 ma examination of the sites indicates that human occupations were located along valley bottom sites during temperate episodes subsequently after a gap of several hundred thousand years industries with handaxes appear in the middle loire basin in the interval between 700 and 600 ka and then continuously from 400 ka these two phases of settlement produced industrial assemblages with clear differences in their responses to the supplies of raw materials and in the modes of making flakes

unrest signals after 46 years of quiescence at cumbre vieja la palma canary islands abstract monogenetic eruptions are the most common volcanic activity in the world however unrest monitoring data are scarce due to the long intervening quiescence periods this study analyzes unrest signals recorded in one of the largest monogenetic fields in the canary islands cumbre vieja la palma two seismic swarms were registered in october 2017 and february 2018 with b values of 1 6 0 1 and 2 3 0 2 respectively suggesting an intense magmatic fluids contribution gas and or magma both swarms were linked to changes in gas emissions increases in hydrogen concentration and r ra c up to 7 52 0 05 were recorded before the first swarm at the sampling point closest to where seismicity was located indicating a deep gas input after the second swarm increases in r ra c and thoron soil concentration were recorded at two locations this dataset is compatible with a stalled magmatic intrusion at ca 25 km depth with an estimated volume between 5 5 10 4 km3 and 3 10 2 km3

seismically induced changes of the fluid signature detected by a multi isotope approach he co2 ch4 n2 at the wettinquelle bad brambach central europe 1 we present a study considering the systematics of gas and isotope compositions 3 he 4 he 13 c co2 13 c ch4 15 n of a permanent magmatic co 2 flux in the hydrothermal system of the spring wettinquelle in bad brambach and their relation to the seismic activity beneath the western eger rift the gas and isotope compositions were monitored for more than 3 years the time series includes periods before during and after a 4 month long seismically active period from the end of august to the end of december 2000 shifts due to admixture of crustal components were found for all monitored isotope ratios during and after the seismically active period in case of helium and nitrogen isotopic anomalies occurred already about 6 weeks before the beginning of the seismically active period contemporaneous with a water level anomaly of the well vl4 near the wettinquelle on the one hand preseismic deformations may be responsible for the observed isotope anomalies on the other hand coseismic fracturing processes in the surroundings of the hypocenters may play a role both effects produce greater permeability and result in the release of crustal fluids the migration and admixture of these crustal components to the permanent upper mantle derived fluid flux result in geochemical anomalies that persist for more than 2 years the results of the detailed isotope monitoring have proven to be an important contribution to understand the geodynamic processes that may presently be going on in the region vogtland nw bohemia

origin and spatial distribution of gas at seismogenic depths of the san andreas fault from drill mud gas analysis abstract data are presented on the molecular composition of drill mud gas from the lower sedimentary section 1800 3987 m of the safod san andreas fault observatory at depth main hole measured on line during drilling as well as c and h isotope data from off line mud gas samples hydrocarbons h 2 and co 2 are the most abundant non atmospheric gases in drill mud when drilling seismogenic zones gas influx into the well at depth is related to the lithology and permeability of the drilled strata larger formation gas influx was detected when drilling through organic rich shales and permeable sandstones the saf san andreas fault encountered between approximately 3100 m and 3450 m borehole depth is generally low in gas but is encompassed by two gas rich zones 2700 2900 m and below 3550 m at the fault margins with enhanced 222 rn activities and distinct gas compositions within the fault two interstratified gas rich lenses 3150 3200 m and 3310 3340 m consist of co 2 and hydrocarbons upper zone but almost exclusively of hydrocarbons lower zone the isotopic composition indicates an organic source of hydrocarbons and co 2 in the entire sedimentary section of the well hydrocarbons in sedimentary strata are partly of microbial origin down to 2500 m borehole depth the contribution of thermogenic gas increases between 2500 m and 3200 m below 3200 m hydrocarbons fully derive from thermal degradation of organic matter the lack of h 2 in the center of the fault and the high concentration of h 2 in the fractured zones at the fault margins are consistent with h 2 formation by interaction of water with fresh silica mineral surfaces generated by tectonic activities however this needs to be verified by laboratory experiments based on these studies it is concluded that the fault zone margins consist of strata with enhanced permeability separated by a low permeability fault center

origin and coseismic behavior of mineral spring gas at byakko japan studied by automated gas chromatographic analyses abstract the origin and coseismic behavior of mineral spring gas were examined on the basis of continual monitoring data for several gas species the automatic monitoring system used in this study consists of two gas chromatographs and a personal computer several gas species can simultaneously be analyzed with these analyzers the system was so stable and sensitive that minute coseismic anomalies in these species could be detected a positive correlation between n 2 ar and ch 4 ar implies that the mineral spring gas is a mixture of atmospheric air and lithospheric gas the lithospheric gas is mainly composed of n 2 and ch 4 and also contains trace amounts of he it is inferred from isotopic data that lithospheric n 2 and ch 4 are thermogenic and he is mostly radiogenic in contrast o 2 and h 2 in trace amounts show large diurnal fluctuations suggesting that these species should be mostly biogenic ten earthquakes felt around the station occurred during the monitoring period and four of them coincided with coseismic anomalies in the he ar ratio the anomalies may be interpreted as follows by the ground motion at these felt quakes he accumulated in the ground was additionally released into the spring water the continual monitoring of these gas species enables us to discuss in detail the origin and behavior of the spring gas and to evaluate background noise of the data

quasi stationary jets transporting surface warm waters across the transition zone between the subtropical and the subarctic gyres in the north pacific 1 surface flow jets and associated sea surface temperature sst distribution are investigated in the northwestern north pacific using satellite derived surface currents and sst data that can resolve fine spatial scale structure the combined use of these data reveals warm tongue phenomena driven by surface geostrophic jets which extend northeastward in the kuroshio oyashio transition area they roughly coincide with the subarctic front saf defined as the 4 c isotherm at 100 m depth the phenomena appear throughout the year with seasonal cycles which do not correspond with that of the subarctic north pacific their positions are affected by bottom topography so that their quasi stationary and consistent features are suggested thus it is implied that these jets play an important role in transporting warm waters toward the subarctic region the time series of sst and current fields describe the jets year to year variability involving some changes in strength and connections with the kuroshio extension ke and demonstrate the effects of advection by the jets on sst fields when ke extends northward at its crests for 1999 2002 one of the jets along saf simultaneously strengthens resulting in high sst region directly over and along the south side of the jet hydrographic data show warm saline water intrusions along the jets their mean fields also reveal that these jets are vertically well developed forming a boundary between the subtropical and subarctic gyres in the north pacific

earthquake source nucleation a physical model for short term precursors abstract ohnaka m 1992 earthquake source nucleation a physical model for short term precursors in t mikumo k aki m ohnaka l j ruff and p k p spudich editors earthquake source physics and earthquake precursors tectonophysics 211 149 178 this paper deals with a quasistatic leading to a quasidynamic at a later time nucleation process that precedes the earthquake dynamic rupture and models of the earthquake source nucleation are put forward based on physical principles a quasistatic to quasidynamic rupture nucleation process is an intrinsic part of the ensuing earthquake dynamic rupture in other words the nucleation process itself is an short term or immediate precursor that occurs in a localized zone during the earthquake nucleation premonitory slip proceeds in the localized nucleation zone and shear stress also decreases gradually in the zone since slip weakening occurs during the nucleation immediate foreshock activity is a part of the nucleation process leading to the mainshock dynamic rupture therefore hypocentral locations of foreshocks are necessarily restricted to lie near the mainshock hypocentre onset of the mainshock rupture whether or not foreshocks occur during the mainshock nucleation depends on how the rupture growth resistance varies on a local to small scale since patches of greater rupture growth resistance are considered to prevail on a local to small scale in the fault zone carrying immediate foreshocks would be one of the major characteristics of earthquakes that nucleate within the brittle seismogenic layer when a mainshock earthquake nucleates within the brittle seismogenic layer and its hypocentre is located near the base of the seismogenic layer immediate foreshocks for this mainshock are necessarily restricted to lie within a localized region shallower than hypocentral depth of the mainshock by contrast the nucleation process below the base of the seismogenic layer is aseismic in nature so that carrying no conspicuous foreshocks would be a common characteristic of interplate earthquakes that nucleate below the base of the brittle seismogenic layer the breakdown strength p the breakdown stress drop b and the critical slip displacement dc are indicative of the rupture growth resistance to estimate depth variations of these parameters the effects of the normal stress n and temperature t on those parameters are examined using available data so far published the combined effects of n and t on p in the brittle to semibrittle regime are found to be represented empirically by p n t po n 1 cosh 50 t 40 sinh 50 t exp 2000 t where po n 135 7 0 750 n and t is measured in k and n in mpa it is found that dc increases sharply with t but is insensitive to n above 300 c while dc depends on n but is insensitive to t below 300 c on the basis of these results variations in p dc and b at mid crustal depths are estimated for quartzo feldspathic rocks for a given geothermal gradient

fluvial history of the sub carpathian basins poland during the last cold stage 60 8 cal ka bp abstract the fluvial landforms of the last cold stage are represented in the sub carpathian basins by a system of 2 3 terraces which grade into alluvial fans of a height of 15 20 8 12 and 6 8 m above the present riverbeds in the mountain foreland in the vistula river valley the 15 20 m high terrace covered with loess extends along the western margin of the sandomierz basin and northern margin of the carpathians away from the mountain margin it passes into the sandy terrace plain with dunes it is formed of at least two interpleniglacial alluvial fills the older one dated at 48 36 ka bp over 50 40 6 ka cal bp and the younger one dated 30 25 ka bp 34 1 29 0 ka cal bp thus pertaining to the upper pleniglacial this latter forms a terrace 15 m high in general accumulation of fluvial sediments interrupted with erosion phases dominated in the mountain foreland during the period 60 25 ka bp over 60 29 ka cal bp the most significant erosion phase took place before the maximum extension of the vistulian weichselian wisconsinian ice sheet i e before 25 20 ka bp 29 24 ka cal bp and was connected with a change from an oceanic to a more continental climate the next alluvial fill of terrace 8 12 m high with remnants of braided river channels was formed at the end of the upper plenivistulian the incision of the river channels below the present channel level was followed by aggradation in the late vistulian 15 13 ka bp 18 2 15 6 ka cal bp accompanied by a change in river channel system from braided to meandering in the wisloka and san river valleys alluvial plains extending by lateral erosion of large meanders were abandoned by rivers mainly in the younger dryas and the preboreal the late vistulian large palaeomeanders are missing along lower sola and lower dunajec these rivers fed from higher mountains had still tendency to braiding the climate cooling of the younger dryas brought an increase in the delivery of bedload to the river channels and a tendency to braiding in vistula valley drwinka depression the expansion of forest in the early holocene reduced the water discharge and the size of meanders as a result their width fallen by 3 5 times alluvial data showed also a distinct humid climatic phase ca 9 5 8 5 ka cal bp

a review of the occurrence form and origin of c bearing species in the khibiny alkaline igneous complex kola peninsula nw russia abstract the khibiny complex hosts a wide variety of carbon bearing species that include both oxidized and reduced varieties oxidised varieties include carbonate minerals especially in the carbonatite complex at the eastern end of the pluton and na carbonate phases reduced varieties include abiogenic hydrocarbon gases particularly methane and ethane dispersed bitumens solid organic substances and graphite the majority of the carbon in the khibiny complex is hosted in either the carbonatite complex or within the so called central arch the central arch is a ring shaped structure which separates khibinites coarse grained eudialite bearing nepheline syenites in the outer part of the complex from lyavochorrites medium grained nepheline syenites and foyaites in the inner part the central arch is petrologically diverse and hosts the major ree enriched apatite nepheline deposits for which the complex is best known it also hosts zones with elevated hydrocarbon dominantly methane gas content and zones of hydrothermally deposited na carbonate mineralisation the hydrocarbon gases are most likely the product of a series of post magmatic abiogenic reactions it is likely that the concentration of apatite nepheline deposits hydrocarbon gases and na carbonate mineralisation is a function of long lived fluid percolation through the central arch fluid migration was facilitated by stress release during cooling and uplift of the khibiny complex as a result carbon with a mantle signature was concentrated into a narrow ring shaped zone

monitoring of hydrogen along the san andreas and calaveras faults in central california in 1980 1984 hydrogen h2 has been monitored continuously at 1 5 m depth at nine sites along the san andreas and calaveras faults in central california since december 1980 site characteristic small noninstrumental diurnal variations were recorded during quiescent periods at most sites abrupt h2 changes were observed concurrently at two sites on the calaveras fault some of these were correlated with oscillatory fault slips large 1000 4000 ppm h2 increases were recorded at some sites on the san andreas fault between july 1982 and november 1983 which may be correlated with eleven m 5 earthquakes that occurred near coalinga during this period we attribute both the h2 increases and the triggering of the earthquakes to a large scale compressive stress field within the ductile mafic crust near the plate boundary the stress perhaps caused bulging of the base of the brittle upper crust and thus caused dilation of the san andreas fault zone allowing the escape of pent up h2 generated by hydration reaction of the mafic crust at the same time mobile serpentinites may have squeezed into the seismogenic fault beneath the coalinga area triggering the earthquakes

climate forcing of fluvial system development an evolution of ideas starting from traditional ideas on the climatic steering of fluvial system dynamics it appears that there are different kinds of climatic influences on system dynamics they vary from direct climatic forcing like peak precipitation to indirect like permafrost and partial forcing like vegetation vegetation or its absence and not directly climate is considered as the main cause of fluvial incision or deposition during temperate or cold periods however other external factors than climate and non climatic factors such as local basin characteristics like subsoil lithology and relief express their effects on the fluvial systems by their role in the energy balance of the river catchment finally internal factors in fluvial system evolution like thresholds and response time should not be neglected

reflection of the glacial interglacial cycle in the evolution of the vistula river basin poland a variety of factors has controlled the evolution of the vistula river valley they include climatically induced changes of the river runoff and sediment load glacial advances and rapid variations of the base level as well as the influence of the tectonic factor the first order climatic cycles are reflected in separate terrace fills the second order fluctuations may be represented by separate cuts and fills by the change of the facies or by the change in the granulometric composition the analysis of the changes in the longitudinal profile helped to discover a great variety of different valley reaches and a general tendency to smooth the long profile during the quaternary

monitoring of helium and carbon isotopes in the western eger rift area czech republic relationships with the 2014 seismic activity and indications for recent 2000 2016 magmatic unrest abstract we report new data of the regional distribution pattern of total gas compositions as well as he and co2 isotopic compositions from 25 gas exhalations in the western eger rift and its surroundings additionally the first time series data from gas exhalations in a clay pit within the cheb basin cb are given at 21 degassing locations the first data were obtained 20 years ago from 7 locations within the degassing center cb and from 3 degassing sites belonging to the marianske lazn ml degassing center neon and argon isotope compositions were determined also co2 is the major component at all degassing sites the 13c values display a small range 1 7 to 5 1 and the 3he 4he ratios vary from 1 9 to 5 9 ra the highest 3he 4he ratios are found at locations along the pocatky plesna fault zone followed by the degassing site in the clay pit on the nova ves fault and the locations on the ml fault at the edge of the cb although gas flow and co2 concentrations in all degassing centers are very high the fractions of mantle derived helium are different with presently up to 94 in relation to the sclm 3he 4he of 6 32 ra in the cb up to 73 in the ml and up to 35 in the karlovy vary degassing center at the locations in the eastern part of the cb a clear progressive increase of the 3he 4he ratio has been observed since the first sampling campaigns there in 1993 and 1994 whereas at the other degassing sites the helium isotope ratio remained essentially the same the progressive increase of the 3he 4he ratio in the eastern part of the cb together with further short time increases up to 6 3 ra at one location bublak before both the 2000 and 2008 earthquake swarms indicate an ongoing magmatic process beneath this area which seems to be associated with the occurrence of seismicity the cb is located close to the nov kostel focal zone where since the beginning of our investigations four strong periods of seismicity with magnitudes 3 occurred the latest gas data confirm our earlier findings time series studies showed that in relation with seismic events decreased 3he 4he ratios were repeatedly observed due to admixed seismically released crustal helium presently the eastern part of the cb is the most active non volcanic region in the european cenozoic rift system with gas signatures similar to those found in free mantle derived gases from the east african rift system

fluvial system response to middle and upper pleistocene climate change in the meurthe and moselle valleys eastern paris basin and rhenish massif abstract research in the meurthe and moselle valleys downstream from the vosges massif has resulted in the definition of the terrace system and in the recognition of the climatic influence on its formation eight alluvial terraces were recognized at less than 100 m relative height an absolute chronology was established for the youngest alluvial terraces based on infrared optically stimulated luminescence and radiocarbon dating this provides evidence that each terrace corresponds to a single glacial interglacial cycle this result is confirmed by the study of numerous sections which present a constant succession of lithofacies in each valley part four alluvial sequences were also defined along the meurthe and moselle valleys reflecting middle and late pleistocene climate change their upper basin developed in the vosges massif was actually covered by glaciers during the pleistocene cold periods the differences between these four alluvial sequences are attributed to the unequal expansion of ice in the upper basins of the meurthe and moselle rivers and their tributaries in spite of these differences the sequences show important similarities main aggradation events correlate with cold periods pleniglacial and lateglacial whereas erosional phases occurred at the warm to cold transitions and secondarily at the pleniglacial lateglacial transitions this evolution is comparable with those already described in other northwestern european valleys especially since the upper saalian

slip dependent friction law and nucleation processes in earthquake rupture abstract matsu ura m kataoka h and shibazaki b 1992 slip dependent friction law and nucleation processes in earthquake rupture in t mikumo k aki m ohnaka l j ruff and p k p spudich editors earthquake source physics and earthquake precursors tectonophysics 211 135 148 we developed a physical model that interprets slip strengthening and slip weakening processes in brittle shear fracture by considering the microscopic interaction between statistically self similar fault surfaces our model successfully describes general features of the constitutive behaviour observed in laboratory experiments of stick slip with the progress of fault slip frictional stress first increases rapidly up to a peak value and then decreases gradually to a constant level the first slip strengthening process can be explained by the increase of frictional resistance in transition from the in phase contact to the random phase contact of fault surfaces the latter slip weakening process can be explained by the decrease of frictional resistance due to the abrasion of surface asperities the trade off between these two processes determines the peak stress and the critical displacement over which the slip weakening proceeds we examined the nucleation process proceeding in a seismogenic zone with the increase of external shear stress through numerical simulations in our model the seismogenic zone is represented by a broad weak zone with a locally strong part asperity on a fault plane the basic equations governing the nucleation process are the equation of equilibrium and the constitutive relation between frictional stress and fault slip we obtained the following results the nucleation process first proceeds quasi statically at the weak portions with the increase of external shear stress then if the constitutive relation at the asperity has a high and narrow peak of stress brittle dynamic rupture occurs in a limited area around the asperity when the constitutive relation has a low and broad peak the dynamic rupture of the asperity does not occur the process is completely aseismic when the peak of stress is high and broad the dynamic rupture of the asperity leads to the catastrophic rupture which extends over the whole region from these results it is concluded that diversity in the nucleation process can be ascribed to difference in the variation of constitutive behaviour along the fault

combined raman microprobe spectrometry and microthermometry of fluid inclusions in minerals from igneous rocks of the gardar province south greenland abstract raman microprobe spectrometry has been applied to analysis of the gaseous phase in individual fluid inclusions in minerals from alkalic igneous rock types and associated hydrothermal veins from the gardar province south greenland quantitative analyses are given for co2 ch4 c2h6 h2 and h2s traces of co were observed in one co2 inclusion in conjunction with data from microthermometry the results permit calculation of the bulk chemical composition of entrapped fluids and evaluation of the possible pressure temperature oxygen fugacity and sulphur fugacity during entrapment of the individual fluid inclusions calculated oxygen fugacity values correspond to those of the nno and qfm buffer reactions at temperatures of 300 400 c and pressures of 0 5 1 0 kbar calculated sulphur fugacity values are within the range of normal ore forming solutions log fs2 6 to 10

variations in stable isotope ratios of ground waters in seismically active regions of california measurements of d and sup 18 o concentrations of ground waters in seismically active regions are potentially useful in earthquake prediction and in elucidating mechanisms operative during earthquakes principles of this method are discussed and some preliminary data regarding a magnitude 5 7 earthquake at the oroville dam in 1975 and a series of events near san juan bautista in 1980 are presented to support the utility of such measurements after earthquakes the d content of nearby ground waters increased by several permil while the sup 18 o content remained constant this increase implies that h sub 2 o may have either decomposed or reacted to form molecular h sub 2 at depth it is emphasized that many areas must be investigated for these effects in order to find a sufficient number of sensitive water wells and springs to permit a truly effective program of earthquake research

geochemical precursors to seismic activity studies of earthquake precursory phenomena during the last several decades have found that significant geophysical and geochemical changes can occur prior to intermediate and large earthquakes among the more intensely investigated geochemical phenomena have been 1 changes in the concentrations of dissolved ions and gases in groundwaters and 2 variations in the concentrations of crustal and mantle volatiles in ground gases the concentration changes have typically showed no conanomalies trend either increasing or decreasing and the spatial and temporal distribution of the observed anomalies have been highly variable as a result there is little agreement on the physical or chemical processes responsible for the observed anomalies mechanisms proposed to account for precursory groundwater anomalies include ultrasonic vibration pressure sensitive solubility pore volume collapse fracture induced increases in reactive surfaces and aquifer breaching fluid mixing precursory changes in soil gas composition have been suggested to result from pore volume collapse micro fracture induced exposure of fresh reactive silicate surfaces and breaching of buried gas rich horizons an analysis of the available field and laboratory data suggests that the aquifer breaching fluid mixing ab fm model can best account for many of the reported changes in temperature dissolved ion and dissolved gas concentrations in groundwater ultrasonic vibration and pressure sensitive solubility models cannot reasonably account for the geochemical variations observed and although the pore collapse model could explain some of the observed chemical changes in groundwater and ground gas uncertainties remain regarding its ability to generate anomalies of the magnitude observed other geochemical anomalies in particular those associated with hydrogen and radon seem best accounted for by increases in reactive surface areas irsa model that may accompany precursory deformation around the epicenter of an impending earthquake analysis of the probable response of these models to the earthquake preparation process as well as to other environmental factors suggests that geochemical monitoring programs can provide information that may be valuable in forecasting the probability of an earthquake however because of the complexity of the earthquake preparation process the absolute prediction of seismic events using geochemical methods alone does not presently appear to be feasible

geogas transport in fractured hard rock correlations with mining seismicity at 3 54 km depth tautona gold mine south africa abstract an on site gas monitoring study has been conducted in the framework of an earthquake laboratory the international nelsam dafgas projects at the tautona gold mine south africa five boreholes up to 60 m long were drilled at 3 54 km depth into the highly fractured pretorius fault zone and instruments for chemical and seismic monitoring installed therein over the span of 4 years sensitive gas monitoring devices were continuously improved to enable the direct observation of geogas concentration variations in the dafgas borehole the major gas concentrations are constant and air like with about 78 n 2 21 o 2 1 ar the geogas components co 2 ch 4 he and h 2 show the most interesting trends and variations on the minute by minute basis and significantly correlate with seismic data while the 222 rn activity remains constant time series and cross correlation analysis allow the identification of different gas components geogas and tunnel air and the identification of two processes influencing the borehole gas composition 1 pumping induced tunnel air breakthrough through networks of initially water saturated fault fractures and 2 seismicity induced permeability enhancement of fault fractures to above 5 10 10 m 2 the current set up of the gas monitoring system is sensitive enough to quantify the resulting geogas transport during periods of intense blasting activities including recorded blasts with seismic moment 1 10 9 nm located within 1000 m of the cubby and it is suggested also during induced earthquakes a final goal of the project

free hydrogen hydrocarbon gases from the lovozero loparite deposit kola peninsula nw russia abstract the lovozero nepheline syenite massif in the north eastern fennoscandian shield well known to mineralogists and petrologists is also interesting with its high contents of hydrogen hydrocarbon gases in different forms of presence which is untypical of magmatic rocks the article systematizes and generalizes little known and unpublished data on the composition location character and scale intensity of the free gases fg emission within a major loparite deposit confined to the massif 4 and 2 are dominant in the fg composition the molecular weight distribution of hydrocarbon gas components corresponds to the classic anderson schulz flory distribution with a steep gradient carbon and hydrogen of the gases are characterized by rather heavy isotope compositions becoming lighter from the transition of methane to ethane the fg volume has been estimated as 0 2 1 6 m 3 of gas per 1 m 3 of undisturbed rock the gas recovery of walls in underground workings has been up to 0 2 ml min m 2 for 4 and 0 5 ml min m 2 for 2 in several years after their heading the discharge of some shot holes that characterizes the gas emission intensity 1 8 2 m deep and 40 mm in diameter is up to 300 ml min but its 1 2 orders lesser values dominate the discharge time in some sections varies from several days to 20 years the overpressure of gases towards the air mainly does not increase 100 hpa sometimes reaching 120 kpa it has been defined that fg distribute irregularly at the distance of centimeters to hundreds of meters and their composition and particularly emission intensity perform different temporal fluctuations the abiogenic origin of fg has been proposed with fg appearing as a mixture of gases in various proportions a gases remaining in microfissures at the massif s consolidation after the capture by fluid inclusions and those lost during degassing and b gases occurred in mechanic chemical reactions partial emission and concentration of occluded and diffusely scattered gases under the unstable stress strain mode of the rock mass combustible and explosive hydrogen hydrocarbon fg can accumulate in the air of underground workings and cause accidents disrupting the workflow the background for using characteristics of spatial temporal variations of the fg emission as precursors of dangerous geodynamic phenomena has been indicated

late devensian river and floodplain dynamics and related environmental change in northwest europe with particular reference to a site at woolhampton berkshire england marked fluctuations in late glacial climate are correlated with significant changes in river behaviour and floodplain environment across much of northwest europe evidence from a new site in the kennet valley provides a rare comprehensive picture of varying fluvial regime and local vegetation during this interval chronological control for the site is provided by biostratigraphical and morphostratigraphical correlations with other sites in the region and by radiocarbon dating of carefully selected material preservation of the sedimentary sequence was facilitated by its occurrence within a large depression in the underlying bedrock the origin of this depression is uncertain perhaps reflecting subsidence or scour following the last glacial maximum a nival regime braided river dominated by floods deposited sandy gravels under stadial conditions a large channel infilled by fine sediments during the latter part of the windermere interstadial indicates a fall in flow competence at a time of increased floodplain vegetation most notably the appearance of tree birch variations in sediments and vegetation suggest fluctuations in the floodplain environment reflecting complex vegetation dynamics and possibly climate forcing during the loch lomond younger dryas stadial a nival braided regime was re established accompanied by the disappearance of tree birch

sensitivity of west and central european river systems to environmental changes during the holocene a review abstract sediment deposition in floodplains is an essential part of the sediment dynamics of a catchment these sediment dynamics can vary largely on a holocene time scale under the influence of driving forces such as land use and climatic variations in this paper we review the holocene floodplain sediment deposition history of rivers in west and central europe with special attention to the influence of climate and land use variability during the early holocene preboreal to atlantic period most floodplains were rather stable with limited floodplain aggradation after this initial phase of relative stability sedimentation rates increase during the middle and late holocene with often the most important deposition phase during the last 1000 to 2000 a the start of the increase in sedimentation varies spatially with an earlier start in the west france germany then in the east poland belarus ukraine while there are also local differences between regions which are settled early e g loess regions compared to later settled regions the sedimentation history of most floodplains can be linked to the local land use history while influence of climatic variations on floodplain aggradation is often reported to be of minor importance processes related to bedload are often reported to be more influenced by climatic events relationships between the driving forces and the sediment history are mainly based on synchronicity and there is seldom proof for a direct causal relationship future research should focus on a system based approach integrating the floodplain deposition in the entire sediment dynamics which includes also erosion colluvial deposition and export main research questions that need further attention include integration of system based concepts like landscape connectivity and buffering effects and also the assessment of the individual contribution of land use changes and climatologic variations on the sediment dynamics detailed sediment budget studies combined with modeling studies can make an important contribution to the understanding of floodplain sediment dynamics

chemical signature detection of groundwater and geothermal waters for evidence of crustal deformation along fault zones abstract common crustal igneous and high grade metamorphic rocks contain peroxy defects which remain dormant until the rock experiences stress upon deformation stress activated peroxy defects form highly reactive oxygen species ros at the rock water interface observed in both terrestrial and extraterrestrial rock samples the ros complex is formed upon rock fluid interaction when groundwater combines with the ros to produce hydrogen peroxide giving an indirect measure of the underlying rock stress and crustal deformation along active faults the average concentration of hydrogen peroxide from the sohna thermal spring water falling along the active sohna fault and geothermal field was measured to be 0 53 0 014 mg l similar average concentration was also recorded from borewell sample north of the spring 0 56 0 017 mg l within the same geothermal field lower concentration of hydrogen peroxide was recorded within samples collected from hard rock aquifers outside the geothermal field and the active fault zone 0 138 0 095 mg l the detailed analysis suggests that the presence of hydrogen peroxide is largely dependent on the circulation pattern through the interconnected fractures joints within the quartzite bedrock lying adjacent to the fault plane laboratory analysis results also show high hydrogen peroxide concentration within two borewell samples falling adjacent to the epicentre of a shallow microtremor event within the hard rock region falling alongside a lineament along the delhi hard rock mega fold rock water interaction post stress activation of peroxy defects and formation of ros has therefore been inferred to be responsible for the formation of hydrogen peroxide at the rock water interface within these zones this pilot study provides scientific field evidence that hydrogen peroxide concentrations within groundwaters might offer prospects for seismic stress estimation and crustal deformation along seismically active zones

recent results of hydrogeochemical studies for earthquake prediction in the ussr the paper reviews the chief results of the hydrogeochemical and hydrogeodynamic investigations conducted for earthquake prediction in all seismic regions of the ussr

experimental studies of the mechanisms of seismo geochemical precursors the following aspects of modeling experiments on seismo geochemical precursors are described 1 gas emission during laboratory stress loading and rupture of rocks 2 field measurements with explosion sources 3 aquifer mixing tests in the field 4 experimental studies of physico chemical processes caused by stress events from these studies three conclusions have been drawn 1 long term seismo geochemical anomalies appear to be related to the stage of elastic deformation of rocks under stress loading prior to a seismic event short term anomalies appear to be related to the plastic deformation of rock and spike like anomalies appear to be related to shear displacement before an earthquake 2 anomalous changes in chemical composition of groundwater and the escape of gases from the ground appear to result from rock fracturing which opens up pathways for the upward migration of water from deep confined aquifers and for the upward migration of gases from the deeper crust 3 chemical reactions induced by increasing stress in the epicentral region may result in the anomalous changes in chemical composition of groundwater observed before some large earthquakes

origin of hydrogen and carbon dioxide in fault gases and its relation to fault activity gases occluded in fracture zones of active faults are characterized by a high concentration of h 2 and or co 2 a predominant gas species h 2 or co 2 is related to the lithofacies which the fault cuts carbon dioxide concentration in sediments fluctuates with temperature this evidence and sigma 13 c of co 2 about 20 suggests that co 2 originates from organic materials carbon dioxide with sigma 13 c of 5 to 17 in brecciated gneiss containing marble may have been produced by interaction between organically derived co 2 and the marble or alternatively may have been magmatically derived hydrogen usually occurs in sheared silicate rocks and its concentration fluctuates a great deal the concentration of h 2 from active faults associated with historical earthquakes usually amounts to as high as several percent in maximum whereas the concentration of h 2 from quaternary faults not associated with historical earthquakes is at most 1

pleistocene fluvial terraces from northern france seine yonne somme synthesis and new results from interglacial deposits the seine yonne and somme are the main rivers draining northwestern france and flowing into the channel during pleistocene cold stages they were tributaries of the fleuve manche they are characterised by well developed stepped terrace systems showing up to 10 incision steps for the last 1 ma after 15 years of research and the synthesis of stratigraphical sedimentological bioclimatical data and numerical dating these terrace systems are interpreted as the response of the fluvial environments to climatic cyclicity superimposed on a background of slow tectonic uplift the comparison of these three terrace systems shows that the incision budget is similar within the studied area about 55 65 m 1 ma implying relative homogeneity of uplift in the main part of the area beyond marine influence the analysis of each stepped alluvial formation shows regular sediment balance generally composed of coarse periglacial gravels pleniglacial covered by fine grained sediments locally overlain by calcareous tufa interglacial however in the lower seine valley close to the present coast the low terrace includes two estuarine interglacial units interbedded within periglacial gravel units nevertheless until recently evidence of full interglacial conditions remained elusive in fluvial contexts especially in the somme to address these issues a new research programme has been launched on tufa deposits that are the best candidate to register the climatic optimum initial results from la celle seine saint acheul and caours somme allow palaeoenvironmental reconstructions of mis 11 and 5e and thus confirm the importance of calcareous tufa to define a reference record of pleistocene interglacials for northern france moreover it has been previously demonstrated that the main incision leading to terrace formation can be attributed to the transition between interglacial and glacial during early glacial phases the new results from interglacial records have important implications concerning the precise occurrence of the major incision phases within the climatic cycle as they provide the starting point immediately preceding downcutting

last glacial interglacial cycle in the evolution of river valleys in southern and central poland abstract the last glacial interglacial cycle is represented usually by several cuts and fills which have formed 2 3 terrace steps from the last cold stage and by two or more fills of lateglacial holocene age their number depends on the size of the river valley and the position in the longitudinal profile the sequence of changes reflects shorter stadial interstadial climatic fluctuations generally aggradation dominates during the cooler phases of the vistulian and during the interpleniglacial the most distinct erosional phases occurred during the change from a more oceanic to a more continental climate before the maximum extension of the ice sheet 25 20 ka bp and during the upper pleniglacial lateglacial transition 15 13 ka bp the second phase coincides with the rapid downcutting in the lower course of the main vistula valley which had been blocked earlier by the scandinavian ice sheet in the holocene aggradation prevailed accelerated by anthropogenic soil erosion it was only in the mountain foreland that shorter lived hydrological changes resulted in well expressed several cuts and fills

earthquake impact on iron isotope signatures recorded in mineral spring water we investigated the iron isotope signatures of dissolved fe in the water of the wettinquelle mineral spring bad brambach germany by time series sampling covering seismically active periods related to tectonic activity near the eger rift system in central europe our objective was to test whether fe isotopes trace earthquake induced abiotic and biotic changes in the fluid rock interaction of the deep fissured granitic aquifer we found that the dissolved fe isotope signatures in spring water are distinct from the granitic source signature 56fe 0 09 particularly we discovered that water 56fe values are remarkably stable 0 01 0 11 2sd n 4 before and during a strong seismic swarm period in 2000 local magnitudes ml 3 while o2 and h2 concentrations in water decrease and dissolved fe content increases later recurring events of lower 56fe values down to 0 3 are observed in the period from 2001 to 2003 with intermittent seismic events 1 ml 2 6 the observations indicate a time lag between tectonic forcing and fe isotope response the role of abiotic fluid rock interaction and fe utilizing bacteria identified in the mineral spring water on fe isotope fractionation is discussed we explain recurring changes towards isotopically lighter values by a combination of fe dissolution from deep granite and admixture of isotopically light fe generated by a complex combination of abiotic and biotic processes operating in the aquifer when disturbed by swarm earthquakes events we propose a conceptual model scenario of earthquake triggered changes in biogeochemical processes

gas geochemistry and seismotectonics a review abstract publications on soil and spring gases have been examined regarding their relationships with both tectonic and seismic activities the main sources behaviours and uses of species detected in soils and springs are displayed and their mode of sampling and analysing briefly described the main patterns of degassing in soils are described and we outline the wide range of geochemical signatures as the result of both permeability and mineralogical contrasts because thermomineral waters have been in contact with great volumes of crustal rocks at various depths spring gases might be more representative of the local environment than soil gases moreover gas signature comparisons show that spring gases are much more enriched with deep gases and slightly contaminated by atmospheric gases therefore they can be considered as better samples for identifying precursors of earthquakes environmental perturbations are examined and it is shown from divergent cases that pressure temperature soil moisture or earth tides may generate very high perturbations of the degassing process such effects demonstrate that no systematic correction law can be proposed and that removing external contributions from gas concentrations must be performed case by case this demonstrates therefore the need for the simultaneous measurement of external parameters during gas monitoring a qualitative examination of about 150 claimed precursors proposed in the literature has been reviewed as noted by previous authors anomalies appear at distances sometimes much greater than typical source dimensions and occur in the field of strain higher than 10 9 most of them being in the field of strain higher than 10 8 taking into account the very high heterogeneity of such a set of data we can suggest that amplitudes of gas anomalies are independent of both magnitudes and epicentral distances of related earthquakes suggesting local conditions to control amplitudes on the contrary precursory time and duration of anomalies seem to increase both with magnitudes and epicentral distances abundant evidence demonstrates the major role of crustal fluids in the earthquake cycle many works have outlined the fact that crustal instabilities can appear as the result of low stress strain perturbations during loading it has been suggested that motion of fluids may occur at various scales from microcrack fluid transfer up to changes of hydraulic levels of water tables the study of subsequent anomalies is expected to supply a tool for earthquake prediction following previous authors we outline the need for further methodological improvements including the setting up of multiparameter station networks and the simultaneous recording of the main external parameters atmospheric pressure water and air temperature soil moisture for signal processing

river terraces as a response to climatic forcing formation processes sedimentary characteristics and sites for human occupation abstract climate impact on the fluvial processes led to morphological and sedimentological differentiation of a terrace this diversity in the fluvial environment determined how people could adapt to the river although the climatic impact on development and initiation of river terraces seems to be well accepted a number of pertinent questions disturb this simplicity for instance the exact terrace development within a climate cycle is still under debate different kinds of terraces and their sedimentary successions may originate either from aggradation incision or lateral migration is there a typical sedimentary succession below terraces what is the genetic origin of each sedimentary layer what are the relative ages of those layers and erosion phases within a climate driven erosion aggradation cycle the variability in staircase preservation in relation to climatic cyclicity is analysed in three scenarios specific scenarios depend essentially on the preservation of the fluvial deposits dating from the warm periods finally a preliminary inventory is presented of the most favourable sites for human occupation in fluvial valleys as derived from a random selection of archaeological findings generally human occupation in that morphological position seems to be linked with at least temporarily dry conditions climatic conditions do not seem to play the major role the termination of a settlement may have been due to increased risks of flooding apart from other than natural fluvio environmental reasons

geological link between fluid inclusions dilatant microcracks and paleostress field seismic investigations using three component instruments have demonstrated shear wave splitting in widely different geological and tectonic environments shear wave analysis suggests that the inferred anisotropy can best be explained if the rocks contain distributions of subparallel subvertical fluid filled microfractures which are aligned according to the current stress field the crampin extensive dilatancy anisotropy eda model geological evidence for widespread fluid activity in the earth s crust supports this hypothesis and suggests that the myriads of planes of microscopic secondary fluid inclusions which characterise most geological materials represent fossil eda cracks field studies confirm a strong spatial relationship between the orientation of fluid inclusion arrays and the paleodirections of maximum compressive stress at elevated temperatures and pressures the healing of fluid filled cracks in the crust of whatever origin is considered to be a fairly rapid process moreover the inclusions which form as a result of crack healing respond to changes in temperature pressure and stress by changing shape and or volume this indicates a high degree of fracture compliance sufficient perhaps to react to rapid changes in the current stress field and associated shear wave splitting though individual inclusions typically 20 m will have no effect on the propagation of seismic waves with wavelengths of tens to hundreds of meters the rock volume sampled by the waves will be rendered anisotropic if the overall average of the inclusions shows a preferred orientation thus fluid inclusions may constitute one of the principal types of fluid filled microcrack described by the eda hypothesis

large scale variability in the midlatitude subtropical and subpolar north pacific ocean observations and causes abstract altimetric data from the 8 yr topex poseidon t p mission oct 1992 jul 2000 are used to investigate large scale circulation changes in the three current systems of the midlatitude north pacific ocean the north pacific current npc the alaska gyre and the western subarctic gyre wsg to facilitate the understanding of the observed changes a two layer ocean model was adopted that includes first mode baroclinic rossby wave dynamics and barotropic sverdrup dynamics the npc intensified steadily over the t p period from 1992 to 1998 much of this intensification is due to the persistent sea surface height ssh drop on the northern side of the npc a similar ssh trend is also found in the interior of the alaska gyre both of these ssh changes are shown to be the result of surface wind stress curl forcing accumulated along the baroclinic rossby wave characteristics initiated from the eastern boundary in addition to the interior ssh signals the intensity of the alaska gyre is shown to depend

h2 generation by reaction between h2o and crushed rock an experimental study on h2 degassing from the active fault zone granite and quartz were crushed under moist conditions in the temperature range of 25 270 c in order to obtain the information on the mechanism operative for h2 degassing along active faults it was found that the amounts of h2 gas released by crushing granite and quartz increased with temperature up to around 200 c and then decreased suddenly the results indicate that h2 gas is generated by a chemical reaction between water and such radicals as si and si o formed on the fresh surfaces when the si o si bonds are destroyed by crushing and that the existence of a maximum for amount of h2 gas is due to the decrease of the lifetime of si o radical at the temperature higher than about 200 c the results lend credence to the possibility that h2 gas is generated in the temperature range of 25 270 c along the active fault through the reaction between groundwater and the fresh surfaces of underground rocks formed by the fault movements

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

a systematic compilation of earthquake precursors article a survey of published scientific literature was undertaken to identify and catalog observed earthquake pre cursors the earthquake precursors selected for analysis included electric and magnetic fields gas emissions groundwater level changes temperature changes surface deformations and seismicity for each of these precursors the published scientific literature was searched to document the statistics of each reported earth quake precursor spatial extent time duration amplitude signal noise ratio to analyze dependence of the observable for each precursor on earthquake magnitude and to explore proposed physical models to explain eachearthquakeprecursor somegeneralcharacteristics wereobservedfortheseprecursoryphenomena first the largest amplitude precursory anomalies tend to occur before the largest magnitude earthquakes also the number of precursory anomalies tends to increase the closer in time to the occurrence of the earthquake finally theprecursoryanomaliestendtooccurclosetotheeventualepicenterof theearthquake ingeneral the physical models indicate that all of the precursory phenomena are related to deformation that occurs near the fault prior to the main earthquake while the models provide plausible physical explanations for the pre cursors there are many free parameters in the models that are poorly resolved

cold core anticyclonic eddies south of the bussol strait in the northwestern subarctic pacific abstract summer hydrographic surveys from 1993 to 1997 in the area south of the kuril islands in the northwestern subarctic pacific showed the existence of anticyclonic eddies south of the bussol strait at almost the same location but with variable sizes and intensities depending on the year every eddy had a cold low salinity and low potential vorticity core suggesting a strong influence from the okhotsk sea water two formation processes and annual variations were found with satellite data analyses one is the case where eddies are locally formed south of the bussol strait and intensified from summer to fall with the supply of okhotsk sea water as observed in 1993 in the other case kuroshio warm core rings that had translated northeastward are arrested near the bussol strait and amplified with the supply of okhotsk sea water as seen from summer to autumn in 1995 in winter eddies tend to move northeastward with decay the 1992 eddy moved northeastward then northward in winter and was eventually

characteristics of mesoscale eddies in the kuroshio oyashio extension region detected from the distribution of the sea surface height anomaly abstract this study investigates the distribution of the sea surface height anomaly ssha with the aim of quantifying the characteristics of mesoscale eddies in the kuroshio oyashio extension region koer where intense mesoscale eddies are commonly observed during hydrographic surveys dense distributions of both anticyclonic eddies aes and cyclonic eddies ces are detected for the first time in koer with sufficient temporal and spatial coverage using the okubo weiss parameter without smoothing their contribution to the total ssha variance is estimated to be about 50 the zones of highest amplitudes are located north and south of the axis of the kuroshio extension ke for aes and ces which represent warm core and cold core rings respectively the areas extend poleward along the japan and kuril kamchatka trenches especially for aes eddies of both polarities and with moderate amplitudes are also recognized along the subarctic front saf eddies in areas north and south of the ke generally pro

gas geochemistry applied to earthquake prediction an overview terrestrial gases in groundwater and soil air have been extensively studied in recent years in seismically active areas especially in ussr china japan and united states in search of premonitory changes that might be useful for earthquake prediction concentrations of radon helium hydrogen mercury carbon dioxide and several other volatiles have been found generally to be anomalously high along active faults suggesting that the faults may be paths of least resistance for the terrestrial gases generated or stored in the earth to escape to the atmosphere temporal gas concentration changes with durations of a few hours to many months have been observed before many large earthquakes at a relatively small number of favorably situated stations at epicentral distances of up to several hundreds of kilometers these sensitive stations are generally located along active faults especially at intersections or bends of faults or some other structurally weak zones possibly because of tectonic strain concentration at such places however gas concentrations especially those measured at or near the ground surface may also be significantly affected by meteorological hydrological and other nontectonic changes in the environment the nontectonically induced variations must be carefully eliminated or recognized in the search of true earthquake related anomalies

geochemical characteristics of underground fluids in some active fault zones in china this paper presents a study of tectonic activity in china by means of fluid geochemical methods it is observed that deep fluids with characteristic chemical and isotopic compositions high values of he and h2 and very low value of tritium have migrated upward at some active faults many fluid geochemical anomalies were observed during periods of seismic activity suggesting the usefulness of fluid geochemical methods for earthquake prediction to properly select monitoring springs or wells and chemical components local geological conditions have to be fully considered

impact of blasting on groundwater composition in a fracture in canada s underground research laboratory groundwater composition in a discrete water bearing fracture in granitic rock at the underground research laboratory manitoba was monitored during a period of underground excavation of adjacent rock to determine the impact of conventional blasting techniques and rock fracturing on the concentration of dissolved constituents this work has relevance to the study of hydrogeochemical anomalies associated with seismic activity short lived anomalies such as decreases in dissolved anion cl f br so4 and gas he rn concentrations and concurrent increases in no3 and o2 concentrations were seen shortly after two blasts located opposite the groundwater sampling site a third blast downstream of the site resulted in variability in dissolved gases concentrations but showed no impact on dissolved anion concentrations the results are compared with various models used to account for hydrogeochemical fluctuations associated with earthquakes the data best fit a general form of the aquifer breaching fluid mixing model in which hydrochemical responses are caused by localized changes in hydraulic conductivity along the plane of a fracture which in turn cause changes in mixing ratio of groundwater at the monitoring site

gas anomalies at three mineral springs and a fumarole before an inland earthquake central japan conspicuous anomalies in gas compositions were observed at a fumarole and three mineral springs about 1 3 months prior to an inland earthquake of 6 8 magnitude in central japan on september 14 1984 the epicentral distances are 9 km for the fumarole and 50 71 and 95 km for the springs the anomalies in he ar n2 ar and ch4 ar ratios of bubble gases from the springs can be attributed to fluctuations in the emission rate of some deep seated gas due to change in pore pressure which is subjected to crustal stress resulting in the earthquake the anomaly at the fumarole showed an increase in discharge rate of deep volcanic gas under a compressional stress near the focal region since the behavior of subsurface fluids represented by he ar and other ratios is presumably controlled by the change of pore pressure temporal variations in the fluids can be used as a strain gauge for the crust on the other hand the precursory emissions of h2 which were observed after changes in he ar and other ratios had occurred may have resulted from a reaction between groundwater and the surface of newly formed cracks the timing and amplitude of the geochemical anomalies are compatible with the result predicted by a dilatancy model without fluid diffusion although h2 emission may be related to groundwater permeation into newly formed cracks monitoring of several gases with automatic gas chromatographs at several stations may be useful for unraveling earthquake mechanisms and for predicting earthquakes

natural laboratory nw bohemia comprehensive fluid studies between 1992 and 2005 used to trace geodynamic processes comprehensive studies of co2 rich fluids close to the swarm earthquake region nov kostel at the czech german border have been started 15 years ago and have in particular included two extended chemical and isotope monitoring studies lasting for several years each the regional surface distribution patterns of the fluid signatures including the identification of the origin of fluid components are the focus of the detailed studies three degassing centers cheb basin marianske lazn and karlovy vary with high co2 flux and the same level of 13c values but different levels of 3he 4he ratios have been identified the studies have located the co2 source and have investigated seismically induced changes in fluid characteristics on the basis of unique weekly sampling campaigns at selected locations a seismically triggered release of crustal helium was confirmed by both monitoring campaigns finally indications for a presently active magmatic process beneath the cheb basin have been found in contrast to volcanically active regions magma accumulation in the study area takes place at the crust mantle boundary and is not yet accompanied by heat transfer to the surface likewise reactive magma derived components are absent in the degassing fluids the area of investigation has the potential to be a natural laboratory for fundamental studies of active geodynamic processes the results of our fluid monitoring including the stunning observation of mantle derived free fluids marked by 3he 4he ratios within the subcontinental mantle range are supported by geophysical findings from seismic studies and geologic indications

climatically controlled terraces in uplifting mountain areas abstract terraces in tectonically active mountains and uplands record both tectonic uplift and rhythmic climatic variations the author discusses the question of how to distinguish the role of both tectonic and climatic factors in central europe with quaternary uplift of the order of 50 100 m climatically controlled terraces are well developed cold stage aggradation is recognised through the interfingering of periglacial alluvial slope and loess deposits erosional activity prevailed in transitional periods then follows a discussion of difficulties connected with the construction of timing and rate of tectonic uplift based on the depth of incision in the bedrock and on facies differentiation the examination of changes in longitudinal profiles of river valleys indicates that unrejuvenated upper valley courses cannot be used for the reconstruction of tectonic uplift finally the author presents several types of adaptation of tectonically determined downcutting and aggradation to quaternary climatic cyclicity

river system evolution and environmental changes during the lateglacial in the paris basin france abstract lateglacial sequences from the paris basin floodplains provide a general overview of the valley s evolution related to climatic changes from the weichselian upper pleniglacial to the beginning of the holocene comparison between morphostratigraphical and palaeobiological data allows discussion of fluvial dynamics and related palaeoenvironmental conditions the upper pleniglacial oldest dryas transition remains poorly documented it is represented by sands and silts deposited by a braided channel network the bolling begins with a significant incision related to a meandering system which is followed by local organic and minerogenic deposition contemporaneous with vegetation development the older dryas is evident in several sequences the allerod appears more stable and the forest extension is accompanied by a thin soil formation on the banks the younger dryas is characterised by a strong infilling of the valleys by calcareous silts this last sharp event precedes a second major downcutting phase which takes place in the early postglacial and is followed by a decline in river flow and sediment supply this evolution reflects a broad regional pattern of fluvial response which illustrates its sensitivity to climatic change the study of various morphosedimentary contexts shows their influence on the fluvio dynamic record and bio proxies which complicates the detection of minor phases

climatic and tectonic controls on the development of the river ognon terrace system eastern france the river ognon in eastern france is the principal drainage of the southwestern vosges mountains its lowermost valley reach is oriented parallel to the northwestern front of the alpine collision zone and is characterized by a well developed terrace system geomorphological sedimentological and geochronological analyses were performed on this terrace system and associated deposits the results allow for reconstructing the pleistocene evolution of the river valley and for concluding on the processes that led to the formation of the terrace system the lithological characterization of the terrace deposits by means of heavy mineral analyses indicates pronounced modifications of the river s drainage area optically stimulated luminescence dating suggests that the last significant catchment modification and associated sediment accumulation correlates with the last glacial advance in the vosges mountains despite the apparently strong impact of climatic processes on the evolution of the river ognon our investigation also indicates a mild tectonic influence on presently observed terrace distribution

anomalous chemical changes in well waters and possible relation to earthquakes water level temperature salinity electric conductivity and ph have been measured periodically for several years at three water wells located along a 17 km segment of the san andreas fault between san jaun bautista and cienega winery in central california water samples were collected at the same time for subsequent chemical analyses in the laboratory some sudden large changes in salinity and conductivity were recorded in early march 1980 at the two wells near san juan bautista these changes coincided approximately with the beginning of an episode of increased local seismicity including a magnitude 4 8 earthquake on april 13 analyses of water samples revealed corresponding changes in ion concentrations especially of na sup ca sup mg sup so sup sub 4 sup hco sup sub 3 f sup and cl sup the observed changes may be the result of mixing of waters from different aquifers through cracks developed in the water barriers by a possible crustal strain episode that may have occurred in the study area

the climatic control of sedimentary environment changes during the weichselian an example from the middle vistula region eastern poland abstract this study presents the sedimentary facies stratigraphic framework and palaeoenvironmental conditions of the weichselian sediments in the middle vistula region based on sedimentological palynological palaeopedological and absolute age studies luminescence and radiocarbon dating a succession of three lithofacial complexes and the pattern of their evolution was distinguished the lowermost fluvial complex is composed of two parts separated by an extensive erosional surface they were deposited in a braided river system during two distinct periods of weichselian climate cooling first at the end of the marine isotope stage 5a and during the entire marine isotope stage mis 4 and then at the end of mis 2 late glacial the middle fluvio aeolian complex was deposited during the late glacial as an effect of alternating fluvial and aeolian processes on abandoned higher river terraces under periglacial conditions discontinuous permafrost it represents a record of climatic amelioration culminating in the succession of tundra vegetation and sparse pine birch forests causing the formation of a soil in the top part of the middle complex the uppermost aeolian complex was deposited during the older and younger dryas as a result of permafrost degradation the deposition was interrupted by the expansion of boreal forest during the allerod and the development of soils climate has been recognized as a major factor determining changes in sedimentary environments the cooling of the climate during the weichselian was conducive to the aggradation of sediments and permafrost in contrast climate warming resulted in increased erosion in the valley and creation of terraces

geochemical monitoring of geothermal waters 2002 2004 along the north anatolian fault zone turkey spatial and temporal variations and relationship to seismic activity a total of nine geothermal fields located along an 800 km long e w transect of the north anatolian fault zone nafz turkey were monitored for three years 2002 2004 inclusive 3 sampling periods per year to investigate any possible relationship between seismic activity and temporal variations in the chemistry and isotope characteristics of waters in the fields the geothermal fields monitored in the study were from west to east yalova efteni bolu mudurnu seben kursunlu cankiri hamamozu gozlek and resadiye the chemical major anion cation contents and isotopic 18o 16o d h 3h compositions of hot and cold waters of the geothermal sites were determined in order to both characterize the chemical nature of the individual fields and identify possible temporal variations associated with localized seismic activity the geothermal waters associated with the nafz are dominantly na hco3 whereas the cold waters are of the ca hco3 type the oxygen and hydrogen isotope compositions reveal that the hot waters are meteoric in origin as are their cold water counterparts however the lower 18o d and 3h contents of the hot waters point to the fact that they are older than the cold waters and that their host aquifers are recharged from higher altitudes with virtually no input from recent post bomb precipitation although no major earthquakes e g with m 5 were recorded along the nafz during the course of the monitoring period variations in the chemical and isotopic compositions of some waters were observed indeed the timing of the chemical isotopic changes seems to correlate with the occurrence of seismic activity of moderate magnitude 3 m 5 close to the sampling sites in this respect cl 3h and ca seem to be the most sensitive tracers of seismically induced crustal perturbations and the yalova and efteni fields appear to be the key localities where the effects of seismic activity on the geothermal fluids are most pronounced over the monitoring period the present study has produced a baseline database for future studies directed at characterizing the effects of moderate major earthquakes on the composition of geothermal waters along the nafz future work involving longer monitoring periods with more frequent sampling intervals should lead to a better understanding of the underlying mechanism s producing the observed chemical and isotopic variations

abiogenic fischer tropsch synthesis of hydrocarbons in alkaline igneous rocks fluid inclusion textural and isotopic evidence from the lovozero complex n w russia a detailed fluid inclusion study has been carried out on the hydrocarbon bearing fluids found in the peralkaline complex lovozero petrographic microthermometric laser raman and bulk gas data are presented and discussed in context with previously published data from lovozero and similar hydrocarbon bearing alkaline complexes in order to further understand the processes which have generated these hydrocarbons ch4 dominated inclusions have been identified in all lovozero samples they occur predominantly as secondary inclusions trapped along cleavage planes and healed fractures together with rare h2o dominant inclusions they are consistently observed in close association with either arfvedsonite crystals partially replaced by aegirine aegirine crystals or areas of zeolitization the majority of inclusions consist of a low density fluid with ch4 homogenisation temperatures between 25 and 120 c those in near surface hand specimens contain ch4 h2 up to 40 mol higher hydrocarbons however inclusions in borehole samples contain ch4 higher hydrocarbons h2 indicating that at depth higher hydrocarbons are more likely to form estimated entrapment temperatures and pressures for these inclusions are 350 c and 0 2 0 7 kbar a population of high density liquid ch4 dominant inclusions have also been recorded mainly in the borehole samples homogenising between 78 and 99 c these consist of pure ch4 trapped between 1 2 and 2 1 kbar and may represent an early ch4 bearing fluid overprinted by the low density population the microthermometric and laser raman data are in agreement with bulk gas data which have recorded significant concentrations of h2 and higher hydrocarbons up to c6h12 in these samples these data combined with published isotopic data for the gases ch4 c2h6 h2 he and ar indicate that these hydrocarbons have an abiogenic crustal origin and were generated during postmagmatic low temperature alteration reactions of the mineral assemblage this would suggest that these data favour a model for formation of hydrocarbons through fischer tropsch type reactions involving an early co2 rich fluid and h2 derived from alteration reactions this is in contrast to the late magmatic model suggested for the formation of hydrocarbons in the similar peralkaline intrusion ilimaussaq at temperatures between 400 and 500 c

eddies advected by time dependent sverdrup circulation in the western boundary of the subarctic north pacific 1 it has been reported that several eddies frequently exist along the kuril kamchatka trench k k trench hereafter the western boundary of the subarctic north pacific lagged correlation maps of the altimeter derived sea level anomalies slas along the trench indicate that the southern eddies on the whole move northeastward along the k k trench and the northern eddies on the other hand move southwestward by tracking each anticyclonic eddy its propagating velocity along the trench is calculated the time series of the tracked 7 eddies shows similar seasonal variation to those of the first empirical orthogonal function eof of the sla maps and to those of the sverdrup transport at 40 n in addition when more than two eddies remotely exist in the studied area they show coherent moving patterns these results suggest that the eddies in the western boundary region of the subarctic north pacific are advected by the time dependent wind driven current

experimental studies of he and ar degassing during rock fracturing abstract we studied degassing of he and ar from granite basalt and volcanic tuff samples which were subjected to uniaxial compression from the samples which were fractured in the dilatant region he was always degassed while degassing of ar dependent not only on the dilatancy but also on the type of rock and the compressional conditions such as wet room dry or vacuum conditions it is concluded that degassing of rare gases from the compressed samples depends primarily on the generation of new surface area by dilatancy

gas geochemical changes at mineral springs associated with the 1995 southern hyogo earthquake m 7 2 japan abstract gas concentrations monitored at a mineral spring in central japan over the past 15 years showed similar changes before and after two large earthquakes september 1984 m 6 9 50 km distant and january 1995 m 7 2 220 km distant namely a concurrent and abrupt drop in all three gas ratios he ar n 2 ar and ch 4 ar several months before the events improved measurements of gas compositions since 1991 and the addition of gas discharge rate monitoring since 1993 disclosed the following features for anomalies in response to small earthquakes as well as the large 1995 event 1 the gas ratios increased for both large and small earthquakes but they did not return to the preseismic values for the large event as they did within a few hours for the small events 2 at the 1995 event the gas discharge rate decreased remarkably 3 h before the event and then increased to higher than preseismic level for several months in contrast coseismic rates at small events generally increased for less than 15 min 3 during a seismically quiet period from january 1993 to december 1994 the variation in the he ar ratio was well correlated with that of gas discharge rate such correlation disappeared in august and september 1994 when the three gas ratios dropped before the large event 4 gas compositions at an auxiliary monitoring site revealed a coseismic change similar to that described above for the 1995 event these lines of evidence show that subsurface fluids may habitually respond to changes in physical conditions relating to earthquake occurrences and thus suggest the usefulness of monitoring subsurface fluids for earthquake prediction

oxygen isotope stage 3 fluvial and eolian successions in europe compared with climate model results abstract fluvial and eolian successions of oxygen isotope stage 3 are compared with global gcm and regional climate rcm modeling experiments of the stage 3 and last glacial maximum climate in europe differences in precipitation between stage 3 stades and interstades were minor which is confirmed by the fluvial successions the fluvial response to climate variation is non uniform and in southern europe more pronounced than in northern europe the model simulations indicate a strong western winter circulation over europe during stage 3 which is supported by the eolian deposits data wind speeds in the last glacial maximum simulation appear modest compared with those of stage 3 which contrasts with the abundance of eolian deposits this suggests that during glacial climates the stabilizing effect of vegetation determines eolian sedimentation rates rather than wind speed stage 3 can be divided into an older part 45 000 cal yr b p with a relatively stable landscape and moist climate and a younger part with more frequent climate change and decreasing landscape stability