imaging and modeling the ionospheric airglow response over hawaii to the tsunami generated by the tohoku earthquake of 11 march 2011 1 although only centimeters in amplitude over the open ocean tsunamis can generate appreciable wave amplitudes in the upper atmosphere including the naturally occurring chemiluminescent airglow layers due to the exponential decrease in density with altitude here we present the first observation of the airglow tsunami signature resulting from the 11 march 2011 tohoku earthquake off the eastern coast of japan these images are taken using a wide angle camera system located at the top of the haleakala volcano on maui hawaii they are correlated with gps measurements of the total electron content from hawaii gps stations and the jason 1 satellite we find waves propagating in the airglow layer from the direction of the earthquake epicenter with a velocity that matches that of the ocean tsunami the first ionospheric signature precedes the modeled ocean tsunami generated by the main shock by approximately one hour these results demonstrate the utility of monitoring the earth s airglow layers for tsunami detection and early warning

rapid inverse modeling of pressure interference tests using trajectory based traveltime and amplitude sensitivities 1 this paper presents an efficient trajectory based approach to integrate transient pressure data into high resolution reservoir and aquifer models the method involves alternating traveltime and peak amplitude matching of pressure response using inverse modeling and is particularly well suited for high resolution subsurface characterization using hydraulic tomography or pressure interference tests compared to traveltime inversion only our proposed approach results in a significantly improved match of the pressure response at the wells and also better estimates of subsurface properties this is accomplished with very little increase in computational cost utilizing the concept of a diffusive time of flight derived from an asymptotic solution of the diffusivity equation we develop analytical approaches to estimate the sensitivities for traveltime and peak amplitude of pressure response to subsurface properties the sensitivities are then used in an iterative least squares minimization to match the pressure data we illustrate our approach using synthetic and field examples in the field application at a fractured limestone formation the predominant fracture patterns emerging from the inversion are shown to be consistent with independent geophysical experiments and borehole data

chile2015 induced magnetic fields on the z component by tsunami wave propagation this study reports the magnetic disturbances due to the chilean tsunami 2015 using 10 ground based magnetometer observatories spread in the pacific ocean covering approximately 150 circ epicentral distance for a time duration of 24 h from the tsunami initiation tsunamigenic disturbances in the z component of the geomagnetic field are investigated the methodologies namely the discrete wavelet transform dwt the newly developed approach called effectiveness wavelet coefficient ewc and intrinsic mode functions imf decomposition are implemented to detect these tsunamigenic disturbances the analysis reveals the presence of an increase of ewc amplitude due to tsunamigenic magnetic disturbances nearly around the tsunami arrival time at each observatory the imf decomposition analysis using 10 40 min levels of decomposition shows the amplified magnetic disturbances around the time of the increase in ewc amplitude in most of the observatories the time of the amplified ewc is consistent with the approximate time of the tsunami arrival while in the other observatories the imf decomposition provides better consistency the results suggest that the methodologies implemented in the present work can be effectively used to characterize the tsunamigenic contributions in the geomagnetic field since the tsunami wavefront propagates towards the pacific ocean covers the time duration as long as 24 h from the tsunami initiation

detection of ionospheric disturbances driven by the 2014 chile tsunami using gps total electron content in new zealand a tsunami propagating in open ocean can produce gravity waves and thus perturb the ionosphere in this study we employ a second order numerical difference method using gps total electron content observed in new zealand to detect the ionospheric disturbances triggered by the chile tsunami that occurred on 1 april 2014 we observe traveling ionospheric disturbances tids which have similar horizontal velocity and direction as the tsunami waves at different times after the event according to the arrival times the latter tids about 14 5 15 h after earthquake can be attributed to the tsunami waves whereas the former one about 12 h 30 min after earthquake could be related to other sources this suggests that besides the propagation velocity and direction the arrival time is also necessary to distinguish tsunami driven tids correctly furthermore we observe the phenomenon that the detected tsunami driven tids are superimposed upon other nontsunami driven ionospheric perturbations far away from the epicenter the superimposed tids eventually separate due to their different propagation velocities

time dependent propagation of tsunami generated acoustic gravity waves in the atmosphere abstracttsunami generated linear acoustic gravity waves in the atmosphere with altitude dependent vertical stratification and horizontal background winds are studied with the long term goal of real

chemostratigraphy of the jurassic system applications limitations and implications for palaeoceanography current chemostratigraphical studies of the jurassic system primarily involve the use of one sedimentary component marine organic carbon one divalent transition metal substituted in carbonate manganese and two isotopic tracers strontium isotope ratios 87 sr 86 sr and carbon isotope ratios 13 c carb and 13 c org in carbonate and in organic matter other parameters such as mg ca and sr ca ratios in calcite oxygen isotope ratios 18 o in carbonate sulphur isotope ratios 34 s in carbonate hosted sulphate nitrogen isotope ratios 15 n org in organic matter osmium isotope ratios 187 os 188 os in black shales and neodymium isotope ratios 143 nd 144 nd in various mineral phases are also useful but at present give poor resolution because the database is incomplete or compromised by various factors stratigraphical patterns in total organic carbon toc can be of either local or regional significance depending on the lateral extent of the former nutrient rich and productive water mass divalent manganese follows a similar pattern being concentrated most probably as a very early diagenetic phase only in oxygen depleted waters that typically underlie zones of elevated organic productivity shifts in mg ca and sr ca ratios on the time scale of ammonite subzones seem largely to reflect temperature changes strontium isotope ratios from pristine skeletal calcite provide a global signal 13 c values from carbonates with minimal diagenetic overprint potentially do the same although small spatial differences in palaeo water mass composition may have been locally significant oxygen isotope determinations on carbonate rocks and fossils generally yield values that are too scattered to be stratigraphically useful because they reflect palaeotemperature the evaporation precipitation balance in sea water and the impact of any diagenesis involving an aqueous phase nitrogen isotope ratios in organic matter reflect the chemistry of ancient water masses as affected by nitrate utilization and denitrification and the stratigraphical pattern of this parameter is more likely to correlate only on a regional basis neodymium isotope ratios in sea water are also water mass dependent and greatly affected by regional sources and oceanic current systems preliminary data on sulphur isotope ratios in carbonates and osmium isotope ratios in organic rich shales both potentially offering global correlation indicate that these tracers may be valuable although the records at present are not sufficiently well established to allow high resolution regional correlation in all cases biostratigraphically well dated reference sections against which the relevant geochemical data have been calibrated are required in the first instance to date studies on the stratigraphical distribution of organic carbon have been principally carried out in both northern boreal and southern tethyan europe carbon isotope stratigraphy has been undertaken primarily but not exclusively on bulk pelagic sediments from the alpine mediterranean or tethyan domain and strontium isotope stratigraphy has been undertaken largely on calcitic skeletal material belemnites and oysters from northern and southern europe in many sections including those containing ammonites multi parameter chemostratigraphy can give resolution that exceeds that attainable by classic biostratigraphical means strontium isotope ratios in skeletal calcite are a particularly powerful tool for illustrating changes in sedimentary rate and revealing gaps in the stratigraphical record

from sumatra 2004 to tohoku oki 2011 the systematic gps detection of the ionospheric signature induced by tsunamigenic earthquakes the recent tsunamigenic earthquake in tohoku 11 march 2011 strongly affirms one more time after the sumatra event 26 december 2004 the necessity to open new paradigms in oceanic monitoring detection of ionospheric anomalies following the sumatra tsunami demonstrated that ionosphere is sensitive to the tsunami propagation observations supported by modeling proved that tsunamigenic ionospheric anomalies are deterministic and reproducible by numerical modeling via the ocean neutral atmosphere ionosphere coupling mechanism in essence tsunami induces internal gravity waves propagating within the neutral atmosphere and detectable in the ionosphere most of the ionospheric anomalies produced by tsunamis were observed in the far field where the tsunami signature in the ionosphere is clearly identifiable in this work we highlight the early signature in the ionosphere produced by tsunamigenic earthquakes and observed by gps measuring the total electron content close to the epicenter we focus on the first hour after the seismic rupture we demonstrate that acoustic gravity waves generated at the epicenter by the direct vertical displacement of the source rupture and the gravity wave coupled with the tsunami can be discriminated with theoretical support we illustrate the systematic nature of those perturbations showing several observations nominally the ionospheric perturbation following the tsunamigenic earthquakes in sumatra on 26 december 2004 and 12 september 2007 in chile on 14 november 2007 in samoa on 29 september 2009 and the recent catastrophic tohoku oki event on 11 march 2011 based on the analytical description we provide tracks for further modeling efforts and clues for the interpretation of complex and thus often misleading observations the routine detection of the early ionospheric anomalies following the rupture highlights the role of ionospheric sounding in the future ocean monitoring and tsunami detection

estimation of fracture zone geometry from steady state hydraulic head data using iterative sequential cokriging the hydrogeology of fractured crystalline rock is often controlled by a few highly conductive features such as faults and or fractures zones accurate modeling of fluid flow and transport in these systems requires that the geometry of these conductive features be characterized explicitly a new method for estimating the geometry of these features is presented the method is an extension of the recently developed geostatistical technique of sequential cokriging in this extension the geometry of the fracture zone is iteratively updated until an update increases the discrepancy between the estimated and observed hydraulic heads results from two hypothetical examples demonstrate that the method can accurately estimate the geometry of highly conductive fracture zones

first report on seismogenic magnetic disturbances over brazilian sector in this work we present a first report on magnetic disturbances over the brazilian sector that occurred on september 16 17 2015 these disturbances are associated with the illapel earthquake using seven magnetometers installed across brazil and distributed within 4500 km from the epicenter the presence of magnetic disturbances is noted 15 min after the time of earthquake the seismometers registered the arrival of the first seismic waves 10 min prior to the observed signatures on magnetic disturbances suggesting that such waves are possibly from seismogenic origin which involves the lithosphere atmosphere ionosphere coupling

duration of the early bajocian and the associated δ13c positive excursion based on cyclostratigraphy the early bajocian about 172 ma ago was a period of tectonic changes a global carbon isotope positive excursion and biological diversification of marine invertebrates e g ammonites radiolarians and coccolithophores unfortunately both the duration of the early bajocian and the associated palaeoenvironmental changes are still poorly constrained we propose here an estimate of the duration of this sub stage based on a cyclostratigraphic analysis of the carbonate content from the chaudon norante section french subalpine basin france the chaudon norante succession has been correlated with les dourbes section using greyscale variations to detect possible local hiatuses the duration estimated here for the entire early bajocian is 4 082 ma two intervals were identified in the positive 13 c excursion an increase of carbon isotope values lasting 1 36 ma and climax isotope values lasting for 2 72 ma a cooling at high latitudes and warming at low latitudes may have enhanced the earth s temperature gradient leading to an increase in humidity which in turn triggered ocean eutrophication at the origin of the 13 c positive excursion supplementary material the complete dataset presented in the paper a colour version of the figure 8 and correlation of 13 c excursions between our studied site and contemporaneous sites are available at www geolsoc org uk sup18555

the 2009 samoa and 2010 chile tsunamis as observed in the ionosphere using gps total electron content 1 ground based global positioning system gps measurements of ionospheric total electron content tec show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following two recent seismic events the samoa earthquake of 29 september 2009 and the chile earthquake of 27 february 2010 both earthquakes produced ocean tsunamis that were destructive to coastal communities near the epicenters and both were observed in tidal gauge and buoy measurements throughout the pacific ocean we observe fluctuations in tec correlated in time space and wave properties with these tsunamis using the jet propulsion laboratory s global ionospheric mapping software these tec measurements were band pass filtered to remove ionospheric tec variations with wavelengths and periods outside the typical range for tsunamis observable variations in tec appear correlated with the tsunamis in some locations hawaii and japan but not in others southern california or near the epicenters where variations are observed the typical amplitude tends to be 0 1 0 2 tec units for these events on the order of 1 of the background tec value these observations are compared to estimates of expected tsunami driven tec variations produced by embry riddle aeronautical university s spectral full wave model an atmosphere ionosphere coupled model and are found to be in good agreement significant tec variations are not always seen when a tsunami is present but in these two events the regions where a strong ocean tsunami was observed coincided with clear tec observations while a lack of clear tec observations coincided with smaller sea surface height amplitudes there exists the potential to apply these detection techniques to real time gps tec data providing estimates of tsunami speed and amplitude that may be useful for early warning systems

nonlinear ionospheric responses to large amplitude infrasonic acoustic waves generated by undersea earthquakes numerical models of ionospheric coupling with the neutral atmosphere are used to investigate perturbations of plasma density vertically integrated total electron content tec neutral velocity and neutral temperature associated with large amplitude acoustic waves generated by the initial ocean surface displacements from strong undersea earthquakes a simplified source model for the 2011 tohoku earthquake is constructed from estimates of initial ocean surface responses to approximate the vertical motions over realistic spatial and temporal scales resulting tec perturbations from modeling case studies appear consistent with observational data reproducing pronounced tec depletions which are shown to be a consequence of the impacts of nonlinear dissipating acoustic waves thermospheric acoustic compressional velocities are 250 300 m s superposed with downward flows of similar amplitudes and temperature perturbations are 300 k while the dominant wave periodicity in the thermosphere is 3 4 min results capture acoustic wave processes including reflection onset of resonance and nonlinear steepening and dissipation ultimately leading to the formation of ionospheric tec depletions holes that are consistent with reported observations three additional simulations illustrate the dependence of atmospheric acoustic wave and subsequent ionospheric responses on the surface displacement amplitude which is varied from the tohoku case study by factors of 1 100 1 10 and 2 collectively results suggest that tec depletions may only accompany very large amplitude thermospheric acoustic waves necessary to induce a nonlinear response here with saturated compressional velocities 200 250 m s generated by sea surface displacements exceeding 1 m occurring over a 3 min time period

identifying fracture zone geometry using simulated annealing and hydraulic connection data a new approach is presented to condition geostatistical simulation of high permeability zones in fractured rock to hydraulic connection data a simulated annealing algorithm generates three dimensional 3 d realizations conditioned to borehole data inferred hydraulic connections between packer isolated borehole intervals and an indicator fracture zone or background k bedrock variogram model of spatial variability we apply the method to data from the u s geological survey mirror lake site in new hampshire where connected high permeability fracture zones exert a strong control on fluid flow at the hundred meter scale single well hydraulic packer tests indicate where permeable fracture zones intersect boreholes and multiple well pumping tests indicate the degree of hydraulic connection between boreholes borehole intervals connected by a fracture zone exhibit similar hydraulic responses whereas intervals not connected by a fracture zone exhibit different responses our approach yields valuable insights into the 3 d geometry of fracture zones at mirror lake statistical analysis of the realizations yields maps of the probabilities of intersecting specific fracture zones with additional wells inverse flow modeling based on the assumption of equivalent porous media is used to estimate hydraulic conductivity and specific storage and to identify those fracture zone geometries that are consistent with hydraulic test data

ionospheric gps total electron content tec disturbances triggered by the 26 december 2004 indian ocean tsunami 1 tsunami ionospheric disturbances tids of the 26 december 2004 mw 9 3 sumatra earthquake are detected by the total electron content tec of ground based receivers of the global positioning system gps in the indian ocean area it is found that the tsunami waves triggered atmospheric disturbances near the sea surface which then traveled upward with an average velocity of about 730 m s 2700 km hr into the ionosphere and significantly disturbed the electron density within it results further show that the tids which have maximum height of about 8 6 17 2 km periods of 10 20 min and horizontal wavelengths of 120 240 km travel away from the epicenter with an average horizontal speed of about 700 km hr 190 m s in the ionosphere

ionospheric ripples excited by superimposed wave fronts associated with rayleigh waves in the thermosphere 1 coseismic ionospheric disturbances cids associated with the 2011 tohoku earthquake off the pacific coast mw 9 0 tohoku eq were examined using total electron content and seismic wave data a faster cid propagated at 3 0 km s only in the west southwest while a slower cid propagated concentrically at 1 2 km s or slower from the tsunami source area taking the propagation speed and oscillation cycle into account the faster cid was associated with a rayleigh wave but the slower cid was associated with an acoustic or gravity wave the north south asymmetry of the cid associated with the rayleigh wave suggests that the rayleigh wave did not act as a point source of the acoustic wave because a point source propagating in all directions must produce symmetric cid in all directions therefore a superimposed wave front of acoustic waves was excited by the rayleigh wave and produced the north south asymmetry of the faster cid due to the magnetic inclination effect which is different from a well known north south asymmetry of cid excited at the epicenter on the other hand above and south of the tsunami source area the cid with a period of 4 min was excited by a point source located at the tsunami source area because atmospheric waves propagating from a point source produce north south asymmetry in the resulting cid

a multidisciplinary fractured rock characterization study at raymond field site raymond ca abstract a dedicated field site was developed and a suite of experiments were conducted in the sierra nevada foothills near the town of raymond ca to develop and test a multi disciplinary approach to the characterization of groundwater flow and transport in fractured rocks a wealth of geologic hydrologic and geophysical data was collected at the site using a variety of unique tools a cluster of nine approximately 90 m deep boreholes were drilled at the site in a v shaped pattern with an angle of 60 the boreholes are spaced 7 5 15 30 and 60 m from the central borehole various geophysical and hydrologic tests were conducted in and between these boreholes integration of cross hole radar and seismic tomography borehole flow surveys and images from a new digital borehole scanner indicated that groundwater flow is mainly confined to a few sub horizontal fracture zones a unique suite of hydraulic tests were conducted in which three to four intervals in each of the nine boreholes were isolated using pneumatic packers some 130 injection tests were conducted and more than 4100 cross hole transient pressure measurements were obtained a computer algorithm was developed to analyze such massive interference data systematically as a result of the analysis an image of the fracture connections emerged which is consistent with the geophysical data high precision tiltmeters were effective in remotely characterizing the preferential flow path several radial convergent tracer tests were conducted by injecting a mixture of several conservative tracers and one sorbing tracer deuterium fluorescein lithium bromide and polystyrene micro spheres some differences between the breakthrough curves are observed which may be due to possible differences among so called conservative tracers some characterization tools were found to be more effective than others in locating flowing fractures however no single tool was almighty characterization of fractured rock is extremely challenging and requires a stepwise and well thought approach which is basically a good old scientific approach prediction of transport based on the characterization results is even more challenging and one should always bear in mind that it is virtually impossible to uniquely characterize a fractured rock

obliquity forcing of organic matter accumulation during oceanic anoxic event 2 1 an analysis of orbitally influenced climate sensitive sedimentation is conducted across a meridional transect of the proto north atlantic to reconstruct the behavior of the carbon cycle and climate during oceanic anoxic event 2 oae 2 94 ma midlatitude to near equatorial sites spanning deep ocean to shelf environments are evaluated using a new inverse method for the identification and calibration of orbital influence in ancient strata the results yield consistent independent astrochronologies at each location compatible with the recently published radioisotopic astrochronologic time scale at the cenomanian turonian gssp and thus provide a unified high resolution temporal context for evaluation of the event the proto north atlantic astrochronologies document an amplification of obliquity power during oae 2 indicating that obliquity was the dominant pacemaker of organic matter accumulation by the latter portion of the event the strong obliquity signal suggests an influence of high latitude climate processes across midlatitude deep ocean to tropical shelf environments changes in oceanic circulation during oae 2 represent a likely mechanism for the propagation of a high latitude signal and proxy data from demerara rise reveal the development of a new intermediate water mass source synchronous with the record of obliquity amplification we hypothesize that a dense high latitude water mass displaced a pre existing nutrient rich anoxic deep water layer in the proto north atlantic augmented by enhanced volcanism driving an episode of high productivity that lasted 700 800 ka the development and intensification of the new intermediate deep water source was potentially driven by eustatic sea level rise which created expansive seaways in mid to high latitudes

phase lagged amplitude modulation of hemipelagic cycles a potential tool for recognition and analysis of sea level change many ancient rhythmic hemipelagic sequences have been interpreted to record orbital variations but the exact nature of the climatic and depositional transfer functions responsible for this link remains poorly understood two dimensional numerical simulations were used to explore selected aspects of orbital signal distortion in linked siliciclastic and hemipelagic systems the models suggest that transfer of multiorder e g 20 100 and 400 k y oscillations in relative sea level into the hemipelagic record produces an inherent amplitude distortion of the shorter period e g 20 k y cycle this distortion gives rise to amplitude modulation am which is qualitatively similar to am of orbitally driven changes in insolation e g eccentricity modulation of precession driven cycles however unlike the orbitally driven am synthesized am is distinctly phase shifted relative to the stratigraphic record of the long period e g 100 k y 400 k y cycle as a result of sealevel driven changes in the storage capacity of nearshore through alluvial parts of the source siliciclastic system hence multiorder changes in sea level can leave a distinct am signature in dilution affected hemipelagic records thus making hemipelagic rhythms due to eccentricity forced sea level changes distinguishable from other types of orbitally driven hemipelagic cyclicity

orbital scale changes in redox condition and biogenic silica detrital fluxes of the middle jurassic radiolarite in tethys sogno lombardy n italy possible link with glaciation abstract orbital forcing has been shown to be a fundamental driver of climate change through both icehouse and greenhouse periods to reveal the impact of orbital forcing on the oceanic environment through a greenhouse icehouse transition we established 4 myr long cyclostratigraphy of the bajocian callovian middle jurassic 160 ma basal radiolarites at the torre de busi and corre di sogno sections in the lombardian basin n italy stratigraphic changes in chert abundance chert shale thickness ratio and color darkness of radiolarites show hierarchal periodicities of 8 cm 16 cm 40 cm 160 cm and 4 m corresponding to 20 kyr 40 kyr 100 kyr 400 kyr and 1 myr cycles based on the biostratigraphic age model black cherts in intervals with high chert abundance might reflect oxygen depleted conditions due to orbital scale high productivity on the other hand black cherts in intervals with low chert abundance high detrital input might reflect oxygen depleted conditions probably due to orbital scale sea level drop and stratification on 40 kyr and 100 kyr cycles the anoxic condition occurred in low chert abundance intervals across 8 m above 2 myr after the base of the radiolarites these results imply that the formation of the restricted basin resulted from tectonic and or eustatic sea level drop which is consistent with increased black chert deposition and redox sensitive elements abundances mo toc mo u their out of phase relationships on the 405 kyr cycle throughout the sequence 4 myr long with increasing amplitude above 8 m level would be caused possibly by tectonic activity or more likely by glacio eustatic sea level changes reported from sequence stratigraphy similar to those of the oligocene to pliocene glacial cycles but probably with less amplitude

modelling of the total electronic content and magnetic field anomalies generated by the 2011 tohoku oki tsunami and associated acoustic gravity waves summary in this work numerical simulations of the atmospheric and ionospheric anomalies are performed for the tohoku oki tsunami 2011 march 11 the tsunami atmosphere ionosphere tai coupling mechanism via acoustic gravity waves agws is explored theoretically using the tai coupled model for the modelled tsunami wave as an input the coupled model simulates the wind density and temperature disturbances or anomalies in the atmosphere and electron density magnetic anomalies in the f region of the ionosphere also presented are the gps total electron content tec and ground based magnetometer measurements during the first hour of tsunami and good agreements are found between modelled and observed anomalies at first within 6 min from the tsunami origin the simulated wind anomaly at 250 km altitude and tec anomaly appear as the dipole shaped disturbances around the epicentre then as the concentric circular wave fronts radially moving away from the epicentre with the horizontal velocity 800 m s 1 after 12 min followed by the slow moving horizontal velocity 250 m s 1 wave disturbance after 30 min the detailed vertical horizontal propagation characteristics suggest that the anomalies appear before and after 30 min are associated with the acoustic and gravity waves respectively similar propagation characteristics are found from the gps tec and magnetic measurements presented here and also reported from recent studies the modelled magnetic anomaly in the f region ionosphere is found to have similar temporal variations with respect to the epicentre distance as that of the magnetic anomaly registered from the ground based magnetometers the high frequency component 10 min of the simulated wind tec and magnetic anomalies in the f region develops within 6 7 min after the initiation of the tsunami suggesting the importance of monitoring the high frequency atmospheric ionospheric anomalies for the early warning these anomalies are found to maximize across the epicentre in the direction opposite to the tsunami propagation suggesting that the large atmospheric ionospheric disturbances are excited in the region where tsunami does not travel

inverse modeling of partitioning interwell tracer tests a streamline approach 1 identifying the location and distribution of nonaqueous phase liquid napl in the subsurface constitutes a vital step in the design and implementation of aquifer remediation schemes in recent years partitioning interwell tracer tests pitt have gained increasing popularity as a means to characterize napl saturation distribution in situ in this method a suite of conservative and partitioning tracers are injected into the contaminated site the chromatographic separation between the conservative and the partitioning tracers can be used to infer napl saturation distribution the conventional approach to the analysis of the tracer response uses a first order method of moments to compute average napl saturation in the tracer swept regions and cannot provide detailed spatial distribution of the napl we propose a computationally efficient streamline based inverse method for analyzing partitioning interwell tracer tests to estimate three dimensional spatial variation of napl saturation in the subsurface our approach is based on an analogy between streamlines and seismic ray tracing and relies on an analytic sensitivity computation method that yields sensitivities of the partitioning tracer response to subsurface parameters such as porosity hydraulic conductivity and napl saturation in a single streamline simulation the inversion of tracer response is carried out in a manner analogous to seismic waveform inversion whereby we first match the first arrival followed by matching the amplitudes of the tracer response the power and utility of the method is illustrated using synthetic and field applications the field example is from the hill airforce base utah where partitioning tracer tests were conducted in an isolated test cell with 4 injection wells 3 extraction wells and 12 multilevel samplers tracer responses from 51 sampling locations are analyzed to determine hydraulic conductivity variations and napl saturation distribution in the test cell finally a performance comparison with simulated annealing shows that our proposed approach is faster by 3 orders of magnitude

lithological dependence of aragonite preservation in monospecific gastropod deposits of the miocene mainz basin implications for the dia genesis of limestone marl alternations

detection and modeling of rayleigh wave induced patterns in the ionosphere 1 global positioning system gps allows the detection of ionospheric disturbances associated with the vertical displacements of most of the major shallow seismic events we describe a method to model the time and space distributions of rayleigh wave induced total electron content tec patterns detected by a dense gps array we highlight the conditions for which a part of the ionospheric pattern can be directly measured at teleseismic distance and above the epicenter in particular a satellite elevation angle lower than 40 is a favorable condition to detect rayleigh wave induced ionospheric waves the coupling between the solid earth and its atmosphere is modeled by computing the normal modes of the solid earth atmosphere system we show the dependency of the coupling efficiency on various atmospheric conditions by summation of the normal modes we model the atmospheric perturbation triggered by a given earthquake this shows that a part of the observation is a rayleigh induced radiation pattern and therefore characteristic of the seismic rupture through atmosphere ionosphere coupling we model the ionospheric perturbation after the description of the local geomagnetic field anisotropic effects we show how the observation geometry is strongly affecting the radiation pattern this study deals with the related data for two earthquakes with far field and near field observations using the japanese gps network geonet after the 12 may 2008 wenchuan earthquake china and after the 25 september 2003 tokachi oki earthquake japan respectively waveforms and patterns are compared with the observed tec perturbations providing a new step toward the use of ionospheric data in seismological applications

traveling ionospheric disturbances propagating ahead of the tohoku oki tsunami a case study we document two kinds of traveling ionospheric disturbances namely ctids co tsunami traveling ionospheric disturbances and atids ahead of tsunami traveling ionospheric disturbances related to the tohoku oki tsunami of 2011 march 11 they are referred to the disturbances that remain behind and ahead of the principal tsunami wave front respectively we first note their presence in a numerical experiment performed using a simulation code coupling the tsunami atmosphere and ionosphere this code uses the tsunami wavefield as an input and simulates acoustic gravity waves agws in the atmosphere and tids in the form of total electron content tec disturbance in the ionosphere the simulated tec reveals the excitation of ctids at about 2 tecu and atids at about 1 tecu representing up to 5 per cent disturbance over the ambient electron density and they arise from the dissipation of agws in the thermosphere a novel outcome is that during the tsunami passage between 6 and 12 of epicentral distance strong atids arrive 20 60 min ahead of the tsunami wave front covering 3 10 of distance from the tsunami location simulation results are compared with the far field observations using gnss satellites and confirm that atids are the first detected tec maximum occurring 20 60 min ahead of the tsunami arrival our simulation also confirms the presence of largest tec maximum representing ctids 10 20 min after the first tsunami wave atids reported in this study have characteristics that can be potentially used for the early warning of the tsunami

tsunami induced phase and amplitude perturbations of subionospheric vlf signals 1 a network of vlf receivers sited in the far east has been used to observe the response of the lower ionosphere to tsunamis resulting from the november 15 2006 kuril region and the march 11 2011 tohoku region earthquakes specific perturbations in the phase and amplitude of vlf signals have been found for both cases a qualitative interpretation of the observed effects is suggested in terms of the interaction of internal gravity waves with lower ionosphere

multiproxy approach to understanding the origin of cretaceous pelagic limestone marl alternations dsdp site 391 blake bahama basin limestone marl alternations are usually directly interpreted to reflect cyclic palaeoenvironmental signals however uncertainty in such interpretations stems from the differential diagenesis that most limestone marl alternations have undergone differential diagenesis results in markedly different alterations between limestones and marls and in the loss of comparability of many measurable parameters for an unequivocal interpretation of the origin of rhythmic alternations diagenetically robust parameters or parameters that clearly indicate the degree of diagenetic bias are required the present study uses a multiproxy approach independent biotic sedimentary and geochemical parameters in order to unravel the palaeoenvironmental signal recorded in valanginian early cretaceous limestone marl alternations from the blake bahama basin dsdp site 391 using this approach terrestrial and marine influences can be distinguished changes in nutrient levels estimated and prediagenetic differences in the non carbonate fraction constrained surprisingly no systematic variations in any of these parameters were observed between limestone and marl layers implying that none of these was directly responsible for the formation of the rhythmic alternation hence none of the current models of sedimentary formation of limestone marl rhythmites is applicable here calcareous nannofossils are equally well preserved in limestone and marl layers ruling out their dissolution in marl layers as a source of the calcite cement in the limestone beds sr values of 700 900 p p m indicate that aragonite may have been present in the original pelagic sediment the assumption of fine grained sedimentary aragonite imported from nearby carbonate platforms as the source of the cement would explain a number of otherwise enigmatic features in these rhythmites including the source of the calcite cement observed in the limestones the equally good preservation of calcareous nannofossils in limestones and marls and the higher concentration of calcareous nannofossils in marl layers the study demonstrates that examination of diagenetically inert parameters or parameters in which diagenetic effects can be filtered can yield unexpected results clearly careful analysis of such parameters needs to be undertaken in order to make reliable palaeoenvironmental interpretations from rhythmite successions

multisite remote sensing for tsunami induced waves in the 2011 tohoku tsunamigenic earthquake ionospheric anomalies generated by tsunami induced gravity waves were observed by many types of instruments three digisondes and one doppler receiver located in east asia were applied to investigate the far field ionospheric response to the westward propagating gravity waves generated by the earthquake based on time period spectrum analysis oscillations between 20 and 36 min on the fo text f 2 critical frequency of f2 layer curves and doppler variations of each observation location were identified the horizontal group speed generation time and source location estimated with the ray tracing method all indicated that the periodic disturbances recorded by the four radio systems were gravity waves induced by the tsunami following the 2011 tohoku earthquake the plasma frequency variations at five fixed altitudes in the ionospheric f2 layer over i cheon were used to investigate the vertical propagation of the tsunami associated gravity waves the measured phase progression in the vertical direction was opposite that of the energy transport which further confirmed that the recorded waves were atmospheric gravity waves the use of multisite remote sensing for examining tsunami induced waves in the ionosphere may open new perspectives in oceanic monitoring and future tsunami warning systems

a new physics based modeling approach for tsunami ionosphere coupling tsunamis can generate gravity waves propagating upward through the atmosphere inducing total electron content tec disturbances in the ionosphere to capture this process we have implemented tsunami generated gravity waves into the global ionosphere thermosphere model gitm to construct a three dimensional physics based model wp wave perturbation gitm wp gitm takes tsunami wave properties including the wave height wave period wavelength and propagation direction as inputs and time dependently characterizes the responses of the upper atmosphere between 100 km and 600 km altitudes we apply wp gitm to simulate the ionosphere above the west coast of the united states around the time when the tsunami associated with the march 2011 tohuku oki earthquke arrived the simulated tec perturbations agree with global positioning system observations reasonably well for the first time a fully self consistent and physics based model has reproduced the gps observed traveling ionospheric signatures of an actual tsunami event

giant ionospheric disturbances excited by the m9 3 sumatra earthquake of 26 december 2004 1 an mw 9 3 earthquake originated in the indian ocean off the western coast of northern sumatra at 00 58 53 universal time ut on 26 december 2004 two giant ionospheric disturbances at 01 19 and 04 10 ut are observed by a network of digital doppler sounders in taiwan the first disturbance excited mainly by rayleigh waves which consists of a packet of short period doppler shift variations results in vertical ionospheric fluctuations with a maximum velocity of about 70 m s and displacement of about 200 m the second disturbance in a w shaped pulse propagating at a horizontal speed of 360 70 m s is attributable to coupling of the atmospheric gravity waves agw excited by broad crustal uplift together with the following big tsunami waves around the earthquake source zone the accompanying ionosonde data suggest that the agw in the atmosphere may have caused the ionosphere to move up and down by about 40 km

observation of tsunami generated ionospheric signatures over hawaii caused by the 16 september 2015 illapel earthquake tsunamis generate internal gravity waves igws that propagate vertically into the atmosphere and can create detectable signatures in the ionosphere these signatures have consistently been observed in the presence of a tsunami for over a decade in the total electron content and for over five years in the 630 0 nm airglow here we show perturbations appearing in filtered gps derived total electron content tec and 630 0 nm airglow above hawaii during the passing of the tsunami induced by the 16 september 2015 earthquake in illapel chile we report measurements of igw parameters from both observation methodologies using a combination of prior methods and a newly developed method that uses a gabor filter bank a previously developed geometric model that takes into account the assumed posture of tsunami induced igws in the geomagnetic field and the observation geometry is shown to predict fairly well the expected location of the observation in the sky results of the gabor filtering technique are also compared to previously published results for the 11 march 2011 tohoku event an overall comparison between all of the tsunami induced signatures that have appeared in both the 630 0 nm airglow and tec above hawaii to date is provided

ionospheric and geomagnetic disturbances caused by the 2008 wenchuan earthquake a revisit previous works have shown that coseismic ionospheric disturbances cids after the tsunamigenic 2011 tohoku earthquake tohoku eq mw9 1 covered a vast area and were observed thousands of kilometers away from the epicenter for the purpose of making a comprehensive comparison between powerful oceanic and inland eqs we conduct a retrospective investigation of cids and geomagnetic responses to the 2008 wenchuan eq mw7 9 using a combination of techniques total electron content hf doppler and ground magnetometer it is the very first study to present cids recorded by different techniques at co located sites and profiled with regard to changes of both ionospheric plasma and current geomagnetic field simultaneously the integrated observation also shows that 1 in the wenchuan case most of the ionospheric and geomagnetic disturbances were observed within 1000 km distance which is far less than the tohoku case 2 two groups of cids were found with maximum amplitudes in the direction of azimuth 150 and 135 respectively and 3 the geomagnetic changes were only registered by three magnetometers located to the east and southeast of the epicenter all the facts indicate that the main directional lobe of wenchuan eq energy propagation is to southeast and perpendicular to the direction of the fault rupture but this kind of directivity is not that distinct in the tohoku case we suggest that the different fault slip inland or submarine affecting the way of couplings of lithosphere with atmosphere may contribute to the discrepancies between the two events

flow and transport in hierarchically fractured rock we construct multiple realizations of hierarchical fracture networks with fractal dimensions between one and two then simulate single well pumping tests and natural gradient tracer tests on them we calculate averages and standard deviations of test results over the multiple realizations and show individual results for selected cases to highlight key features of flow and transport through hierarchically fractured rock these studies are intended to illustrate the range of possible behavior that can be obtained during fracture dominated hydraulic and tracer tests and provide insights into how to interpret field responses the fractal dimension of the fracture network itself is generally larger than the fractal dimension of the flow field arising during a well test the performance measures of the natural gradient tracer tests including the total flow through the fracture network tracer travel time front width and maximum breakthrough concentration can all be correlated to fractal dimension although some of the features observed in the flow and transport behavior within the hierarchically fractured rock have been observed by other authors using non fractal fracture network concepts e g channelized flow with early breakthrough times crossing breakthrough curves others arise directly from the fractal nature of the fracture network in which variability occurs on all scales e g front width and maximum breakthrough concentration that are constant over a wide range of fractal dimensions generally transport simulations show large variability within a given realization and among realizations with the same fractal dimension even in networks whose dimension is close to two this finding is consistent with the large variability in experimental results observed at fractured rock field sites

a methodology to interpret cross hole tests in a granite block water flow through low permeability fractured media is often concentrated in a small number of fractures this fractures need to be characterized in order to simulate accurately the hydraulic behaviour of such media we present a methodology to identify the most significant water conductive fractures the method is based on the interpretation of cross hole tests and is supported by geology geophysics and hydraulic data the methodology has been applied to the hydrogeological characterization of a granitic block around the febex experiment at the grimsel underground laboratory switzerland geology and geophysics are used for identifying candidates to flow controlling fractures single borehole hydraulic tests help in neglecting those with low transmissivity but the only means to assess connectivity consists of performing cross hole tests the resulting geometry is later implemented into a 3d finite element mesh where the fractures are simulated as 2d elements embedded into a 3d porous medium the latter includes the effect of minor fracturing and can be heterogeneous and anisotropic the resulting model is calibrated to obtain an integrated model this methodology has proven capable of reproducing single hole and cross hole tests and steady state heads and also of quantifying groundwater flow to the experimental area of the febex tunnel

seeing red in cyclic stratigraphy spectral noise estimation for astrochronology 1 fundamental to the development of astronomical time scales is the recognition of oscillatory variability within stratigraphic data and its evaluation relative to a null noise hypothesis in this study monte carlo simulations are used to investigate the suitability of two commonly used noise hypotheses the conventional and robust ar1 approaches and the results highlight important limitations in both for cyclostratigraphic application perhaps most problematic the robust ar1 method can result in inflated confidence level estimates and excessive clumping of false positives within the low frequency portion of the spectrum especially when the underlying noise process has a high lag 1 autocorrelation given typical cyclostratigraphic records this technique will often impose significant eccentricity band variability even in the case of pure ar1 noise an alternative spectral noise estimation method is proposed to overcome these problems which simultaneously allows for departures from the ar1 assumption and obtains high statistical power that is the ability to accurately identify astronomical signals when they are present in the data we apply the method to un tuned 18o data from miocene sediments of the ceara rise indicating statistically significant spectral power at frequencies that are consistent with the published orbital interpretation of weedon et al 1997 furthermore evaluation of the frequency arrangement of the significant spatial bedding periods using the average spectral misfit method for astrochronologic testing reveals that the null hypothesis of no orbital influence can be rejected with a high degree of confidence the 99 8 confidence level

astronomically paced coccolith size variations during the early pliensbachian early jurassic though climate and environmental changes are known to influence diversity and assemblages of coccolithophorids unicellular photoautotroph algae the relationships between the size fluctuations of coccoliths the small calcite plates covering the coccolithophorid cell and environmental parameters remain unclear to understand possible interactions between coccolith size and environmental changes a high resolution every 5 cm biometric study of crepidolithus crassus coccoliths was performed in the lower pliensbachian lower jurassic similar to 188 myr hemipelagic deposits of peniche portugal the six measured parameters show covariant patterns related to size variations rather than morphological changes the size variations are cyclic and they occur in opposite phase to changes in the sedimentary calcium carbonate content spectral analyses performed on the size measurements of the c crassus coccoliths and the calcium carbonate contents show that changes in both parameters are paced by the earth s eccentricity and precession orbital cycles as revealed by mixture analyses the observed size variations result from changes in the relative abundance of two distinct biometric groups that are statistically stable through the analysed time interval these two groups are classified as small crassus with a major axis mean size of 6 5 0 75 mu m and large crassus which averages at 8 5 0 75 mu m and dominates the assemblages in the studied interval crepidolithus crassus has been recently interpreted as a deep dweller living in the lower photic zone and its development may have been greatly dependent on light availability and nutrient concentration accordingly the two size groups likely developed at different water depths due to differential coccolith and cell masses and buoyancies consequently we propose that changes in the transparency of the water column may have been an important factor controlling the replacement between the two groups and hence the resulting coccolith mean size fluctuations ultimately both water transparency and nutrient recycling within the photic zone were mainly influenced by the frequency and intensity of storms that occurred under orbital control

evidence of precessional and eccentricity orbital cycles in a tithonian source rock the mid outer carbonate ramp of the vaca muerta formation northern neuquen basin argentina basin to mid ramp cyclic facies of the tithonian vaca muerta formation are exposed in the loncoche creek section of the neuquen basin mendoza province argentina this unit is characterized by a decimeter scale rhythmic alternation of marls shales and limestones and extends from the lower tithonian to the upper berriasian cyclostratigraphic studies based on a detailed facies analysis allowed the identification of cyclic patterns with frequencies within the milankovitch band according to biostratigraphic data the dominant cycle in the studied section has a period of 20 k y which correlates with the earth s axis precession element spectral analysis based on a series of compacted and decompacted cycle thickness identified a subordinate frequency of about 90 to 120 k y which we interpret as the modulation of the precessional cycle caused by the earth s orbital eccentricity the strength of the precession signal together with the absence of a well defined cyclicity attributable to the obliquity orbital cycle i e 40 k y is in agreement with previous data from the northern hemisphere

combined sea level and climate controls on limestone formation hiatuses and ammonite preservation in the blue lias formation south britain uppermost triassic lower jurassic

atmospheric gravity waves due to the tohoku oki tsunami observed in the thermosphere by goce oceanic tsunami waves couple with atmospheric gravity waves as previously observed through ionospheric and airglow perturbations aerodynamic velocities and density variations are computed from gravity field and steady state ocean circulation explorer goce accelerometer and thruster data during tohoku oki tsunami propagation high frequency perturbations of these parameters are observed during three expected crossings of the tsunami generated gravity waves by the goce satellite from theoretical relations between air density and vertical and horizontal velocities inside the gravity wave we demonstrate that the measured perturbations are consistent with a gravity wave generated by the tsunami and provide a way to estimate the propagation azimuth of the gravity wave moreover because goce measurements can constrain the wave polarization a marker noted c3 of any gravity wave crossing by the goce satellite is constructed from correlation coefficients between the observed atmospheric state parameters these observations validate a new observation tool of thermospheric gravity waves generated by tsunamis above the open ocean

high resolution carbon cycle and seawater temperature evolution during the early jurassic sinemurian early pliensbachian the early jurassic was marked by a progressive recovery from the end triassic mass extinction and punctuated by recurring episodes of anoxia these changes associated with fluctuations in carbon isotope composition of marine carbonates remain incompletely understood here we present a high resolution carbon and oxygen isotope record for the early jurassic based on well preserved marine mollusks belemnites from dorset uk our new data show a number of 13c excursions starting with a negative excursion at the sinemurian pliensbachian boundary event followed by lesser negative excursions showing in the polymorphous jamesoni and masseanum valdani subzones the recognition of the sinemurian pliensbachian boundary event in this study and elsewhere suggests that observed carbon isotope trends are likely to represent a supra regional perturbation of the carbon cycle a prominent positive carbon isotope event is also seen within the pliensbachian ibex zone this event is also clearly evident in the data from belemnites from spain this carbon isotope excursion is not however coincident with inferred peak temperatures the oxygen isotope and mg ca data allows the determination of a number of pronounced pliensbachian cool events from the low point in the brevispina subzone oxygen isotopes become more negative coupled with an increase in mg ca values culminating in an early pliensbachian thermal maximum during the davoei zone taken with existing data it appears that the pliensbachian is characterized by 2 major warmings firstly within the davoei zone followed by warming beginning in the latest pliensbachian and peaking in the early toarcian this article is protected by copyright all rights reserved

analysis of observed and predicted tsunami travel times for the pacific and indian oceans i have examined over 1500 historical tsunami travel time records for 127 tsunamigenic earthquakes that occurred in the pacific and indian oceans after subjecting the observations to simple tests to rule out gross errors i compare the remaining reports to simple travel time predictions using huygens method and the long wave approximation thus simulating the calculations that typically take place in a tsunami warning situation in general i find a high correspondence between predicted and reported travel times however significant departures exist some outliers imply significantly slower propagation speeds than predicted many of these are clearly the consequences of observers not being able to detect the possibly weak first arrivals other outliers imply excessively long predicted travel times these outliers reflect peculiar geometric and bathymetric conditions that are poorly represented in global bathymetric grids leading to longer propagation paths and consequently increased travel times analysis of t the difference between observed and predicted travel time yields a mean t of 19 minutes with a standard deviation of 131 minutes robust statistics being less sensitive to outliers yield a median t of just 18 seconds and a median absolute deviation of 33 minutes care is needed to process bathymetry to avoid excessive travel time delays in shallow areas i also show that a 2 2 arc minute grid yields better results that a 5 5 arc minute grid the latter in general yielding slightly slower propagation predictions the largest remaining source of error appears to be the inadequacy of the point source approximation to the finite tsunami generating area

traveling ionospheric disturbances over the united states induced by gravity waves from the 2011 tohoku tsunami and comparison with gravity wave dissipative theory

tsunami wave height estimation from gps derived ionospheric data large underwater earthquakes mw 7 can transmit part of their energy to the surrounding ocean through large seafloor motions generating tsunamis that propagate over long distances the forcing effect of tsunami waves on the atmosphere generates internal gravity waves that when they reach the upper atmosphere produce ionospheric perturbations these perturbations are frequently observed in the total electron content tec measured by multifrequency global navigation satellite systems gnss such as gps glonass and in the future galileo this paper describes the first inversion of the variation in sea level derived from gps tec data we used a least squares inversion through a normal mode summation modeling this technique was applied to three tsunamis in far field associated to the 2012 haida gwaii 2006 kuril islands and 2011 tohoku events and for tohoku also in close field with the exception of the tohoku far field case for which the tsunami reconstruction by the tec inversion is less efficient due to the ionospheric noise background associated to geomagnetic storm which occurred on the earthquake day we show that the peak to peak amplitude of the sea level variation inverted by this method can be compared to the tsunami wave height measured by a dart buoy with an error of less than 20 this demonstrates that the inversion of tec data with a tsunami normal mode summation approach is able to estimate quite accurately the amplitude and waveform of the first tsunami arrival

ionospheric gravity waves detected offshore hawaii after tsunamis 1 on board satellites techniques provide global coverage and could play an important role in the continuous oceanic survey to prevent the damage produced by powerful tsunamis we report here new ionospheric observations related to three significant transpacific tsunami events triggered by the 2006 kuril earthquake the 2009 samoa earthquake and the 2010 chile earthquake total electron content tec variations extracted from data recorded by a dense global positioning system gps network based in hawaii show ionospheric disturbances within the hours following the tsunami wave passage at sea level for each event we observe ionospheric gravity waves propagating with velocity direction and arrival time coherent with the tsunami the tsunamigenic signature in the ionosphere is also compared to in situ sea level measurements these observations provide new examples of the sensitivity of the ionosphere to tsunamigenic gravity waves and confirm that ionospheric monitoring by gps can provide complementary information on tsunami propagation

three dimensional waveform modeling of ionospheric signature induced by the 2004 sumatra tsunami 1 the sumatra december 26th 2004 tsunami produced internal gravity waves in the neutral atmosphere and large disturbances in the overlying ionospheric plasma to corroborate the tsunamigenic hypothesis of these perturbations we reproduce with a 3d numerical modeling of the ocean atmosphere ionosphere coupling the tsunami signature in the total electron content tec data measured by the jason 1 and topex poseidon satellite altimeters the agreement between the observed and synthetic tec shows that ionospheric remote sensing can provide new tools for offshore tsunami detection and monitoring

limestone marl alternations as environmental archives and the role of early diagenesis a critical review limestone marl alternations and other micritic calcareous rhythmites have long appealed to sedimentologists as they appeared to directly reflect high frequency environmental change in particular when orbital forcing gained popularity amongst sedimentologists and paleoclimatologists in 1980s such rhythmites seemed to offer an ideal tool for high resolution chronostratigraphy and environmental reconstruction however in spite of the fact that orbital forcing has become a routine interpretation of calcareous rhythmites and that the processes of formation of calcareous rhythmites are considered well understood research in the past 10 years again has questioned their primary origin and their direct interpretability detailed petrographic paleontological and geochemical data from numerous successions through geological time provided the basis for testing whether or not the regular alternation of limestone beds and marl or shale interlayers represents bimodally fluctuating environmental conditions in a direct way in particular these data supplemented by box model simulations imply that post depositional alteration diagenesis has the potential to not only seriously distort primary environmental signals but also to mimic primary signals this questions the use of micritic calcareous rhythmites for high resolution chronostratigraphy and for environmental interpretations where independent data of diagenetically inert parameters are not available diagenetic changes appear to have a yet widely underestimated influence on the appearance of limestone marl alternations and other calcareous rhythmites the aim of the present review is to summarize new approaches and give an overview of our research results in this field of the past decade this review also aims at pointing to still enigmatic aspects that need to be addressed before the interpretation of micritic calcareous rhythmites can be considered a reliable tool for high resolution chronostratigraphy and paleoenvironmental interpretation

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

astronomical forcing and chronology of the early toarcian early jurassic oceanic anoxic event in yorkshire uk 1 during the early toarcian 183 ma ago a high rate of organic carbon burial globally over a brief interval of time has led to the recognition of a major oceanic anoxic event oae a pronounced negative excursion in the carbon isotope composition of marine organic matter marine carbonate and terrestrial plant material is a key feature of this event but the precise timescale and cause s of this isotopic anomaly are debated associated with the negative carbon isotope excursion is evidence for a coeval rise in seawater palaeotemperature an increase in continental weathering rates and the mass extinction of marine invertebrate species the early toarcian oae provides evidence for the earth s response during rapid climate change and critical to our understanding of the event is a high resolution timescale that allows us to quantify the rates duration and lead lag times of environmental processes in this study we present 2743 new high resolution organic carbon sulphur and carbonate concentration data from samples of well preserved organic rich mudrocks spanning the early toarcian oae in yorkshire uk we have used these data to document the geochemical changes and significantly extend and refine the astronomical timescale across this event our detailed analysis of the relationship between astronomical forcing and carbon isotope changes in both yorkshire and a section from peniche portugal indicates that astronomical forcing paced the timing of major shifts in 13c and hence climate in both sections our analyses also demonstrate that there was a marked increase in the relative strength of astronomical forcing recorded at the onset of the oae and that the recorded nature of astronomical forcing changed during the event both the yorkshire and peniche cyclostratigraphies suggest that one astronomical forcing parameter paced environmental change through the 13c event and that this parameter was obliquity or precession

medium scale traveling ionospheric disturbances induced by typhoon chan hom over china this paper reports the ionospheric response to typhoon chan hom using global positioning system network data from china combined with observations of an ionosonde chain two medium scale traveling ionospheric disturbances mstids were observed around the two landing times of typhoon chan hom the mstid with a phase fronts aligned in the north south direction was detected on the east coast of china at 16 50 18 40 ut on 11 july 2015 and moved westward with a mean horizontal phase velocity of 268 m s and period of 56 min then the concentric mstid appeared on the northeast of china at 01 50 05 10 ut on 13 july 2015 and propagated in the radial direction with average horizontal phase velocity of 143 m s and period of 45 min there may be some connections between the north south aligned mstid and the electrodynamical coupling of the sporadic e layer and the f layer while the concentric mstid may be caused by the concentric gravity waves resulting from the bodyforces related with the typhoon

parameters of seismic source as deduced from 1 hz ionospheric gps data case study of the 2011 tohoku oki event following the first time ionospheric imaging of a seismic fault here we perform a case study on retrieval of parameters of the extended seismic source ruptured during the great m9 0 tohoku oki earthquake using 1 hz ionospheric gps data from the japanese network of gps receivers geonet and several gps satellites we analyze spatiotemporal characteristics of coseismic ionospheric perturbations and we obtain information on the dimensions and location of the sea surface uplift seismic source we further assess the criterion for the successful determination of seismic parameters from the ionosphere the detection is possible when the line of sights from satellites to receivers cross the ionosphere above the seismic fault region besides we demonstrate that the multisegment structure of the seismic fault of the tohoku oki earthquake can be seen in high rate ionospheric gps data overall our results show that under certain conditions ionospheric gps derived tec measurements could complement the currently working systems or independent ionospherically based system might be developed in the future

advantage of wavelet technique to highlight the observed geomagnetic perturbations linked to the chilean tsunami 2010 the vertical component z of the geomagnetic field observed by ground based observatories of the international real time magnetic observatory network has been used to analyze the induced magnetic fields produced by the movement of a tsunami electrically conducting sea water through the geomagnetic field we focus on the survey of minutely sampled geomagnetic variations induced by the tsunami of 27 february 2010 at easter island ipm and papeete ppt observatories in order to detect the tsunami disturbances in the geomagnetic data we used wavelet techniques we have observed an 85 correlation between the z component variation and the tide gauge measurements in period range of 10 to 30 min which may be due to two physical mechanisms gravity waves and the electric currents in the sea as an auxiliary tool to verify the disturbed magnetic fields we used the maximum variance analysis mva at ppt the analyses show local magnetic variations associated with the tsunami arriving in advance of sea surface fluctuations by about 2 h the first interpretation of the results suggests that wavelet techniques and mva can be effectively used to characterize the tsunami contributions to the geomagnetic field and further used to calibrate tsunami models and implemented to real time analysis for forecast tsunami scenarios

required but disguised environmental signals in limestone marl alternations the nature of rhythmic carbonate rich successions such as limestone marl alternations has been and still is subject to controversy the possibility of an entirely diagenetic origin for the rhythmic calcareous alternations is discarded by most authors one problem with an entirely diagenetic self organized development of limestone marl alternations is the fact that limestone and marl beds in many examples are laterally continuous over hundreds of meters or even kilometers in an entirely self organized system lateral coupling would be very limited thus one would expect that rather than laterally continuous beds randomly distributed elongate nodules would form we address the origin of limestone marl alternations using a computer model that simulates differential diagenesis of rhythmic calcareous successions the setup uses a cellular automaton model to test whether laterally extensive rhythmic calcareous alternations could develop from homogeneous sediments in a process of self organization our model is a strong simplification of early diagenesis in fine grained partly calcareous sediments it includes the relevant key mechanisms to the question whether an external trigger is required in order to obtain laterally extensive limestone marl alternations our model shows that diagenetic self organization alone is not sufficient to produce laterally extensive correlatable beds although an external control on bedding formation could be considered to have solved the problem as commonly assumed we here suggest an interesting third possibility the rhythmic alternations were formed through the interaction of both an external trigger and diagenetic self organization in particular we observe that a very limited external trigger either in time or amplitude readily forms correlatable beds in our otherwise diagenetic model remarkably the resulting rhythmites often do not mirror the external trigger in a one to one fashion and may differ in phase frequency and number of couplets therefore the interpretation of calcareous rhythmites as a one to one archive of climate fluctuations may be misleading parameters independent of diagenetic alteration should be considered for unequivocal interpretation

tsunamigenic ionospheric hole 1 traveling ionospheric disturbances generated by an epicentral ground sea surface motion ionospheric disturbances associated with rayleigh waves as well as post seismic 4 minute monoperiodic atmospheric resonances and other period atmospheric oscillations have been observed in large earthquakes in addition a giant tsunami after the subduction earthquake produces an ionospheric hole which is widely a sudden depletion of ionospheric total electron content tec in the hundred kilometer scale and lasts for a few tens of minutes over the tsunami source area the tsunamigenic ionospheric hole detected by the tec measurement with global position system gps was found in the 2011 m9 0 off the pacific coast of tohoku the 2010 m8 8 chile and the 2004 m9 1 sumatra earthquakes this occurs because plasma is descending at the lower thermosphere where the recombination of ions and electrons is high through the meter scale downwelling of sea surface at the tsunami source area and is highly depleted due to the chemical processes

effects of karoo ferrar volcanism and astronomical cycles on the toarcian oceanic anoxic events early jurassic abstract one of the most profound environmental changes in the mesozoic took place during pliensbachian toarcian early jurassic including oceanic anoxia toarcian oceanic anoxic event t oae the t oae is thought to have been caused by increased atmospheric co 2 triggered by karoo ferrar volcanism this idea however remains debated primarily due to uncertainties in their age constraints of the relevant sedimentary sequences to examine their temporal relationships herein we provide the astronomical time scale of the lower jurassic deep sea bedded chert sequences from the pelagic panthalassa superocean which are exposed in the inuyama area central japan a 405 kyr tuned astrochronology anchored to the end triassic extinction as 201 4 0 2 ma ikeda and tada 2013 allows us to constrain the ages of two black bedded cherts t oae1 and t oae2 the ages of these t oaes overlap u pb ages of karoo volcanic rocks t oae in the european region is also synchronous with the karoo ferrar volcanism based on radiolarian and ammonite biostratigraphic correlation these temporal relationships support the potential impact of karoo ferrar volcanism on t oaes on a global scale on the other hand the onset of t oaes occur at the maxima of 40 kyr 100 kyr and 405 kyr cycles of chert thickness variation the termination of t oaes and the recovery to oxic conditions in pelagic ocean coincide with the minima of 40 kyr 100 kyr and 405 kyr cycles of chert thickness moreover the termination of final black chert and grey chert deposition coincide with the minima of 1800 kyr cycles of chert thickness these temporal relationships imply that orbital scale productivity cycles were important in controlling the onset and termination of t oaes through the carbon cycle dynamics which have been already amplified by karoo ferrar volcanism

geomagnetic dependence of ionospheric disturbances induced by tsunamigenic internal gravity waves summary a series of ionospheric anomalies following the sumatra tsunami has been recently reported in the literature these anomalies show the signature in the ionosphere of tsunami generated internal gravity waves igw propagating in the neutral atmosphere over the ocean all these anomalies observed in the total electron content tec measured by gps or altimeters show geographical heterogeneity in the perturbed tec amplitude and suggest a dependence on geomagnetic latitude this latitudinal dependence has been taken into account in the previous 3 d modelling used for the interpretation of the tec topex and jason data here we present an accurate description of the ocean atmosphere ionosphere coupling method and focus on the properties of the propagation of tsunamigenic igw in the neutral atmosphere and their interaction with the ionospheric plasma the analytical dependence on the geomagnetic field in the neutral plasma coupling discussed in detail and quantitative modelling is used to describe the propagation of a simple tsunami wave at the global scale what emphasize the role of geomagnetic field within the neutral plasma coupling at the equatorial and mid latitude regions the results presented here in terms of electron density and tec variations show a strong geometric dependance involving the magnetic field inclination and the propagative direction of the tsunami if the strongest electron density and tec perturbations are located around 15 0 and 15 north the structure and amplitude of the modelled perturbation changes in the two

sedimentary vs diagenetic control on rhythmic calcareous successions pliensbachian of asturias spain the diagenetic overprint in rhythmic hemipelagic successions can either enhance or change the original distribution of caco3 but it is difficult to evaluate its effect because in most field examples it is not possible to distinguish between sedimentary and diagenetic features the rhythmic succession of the pliensbachian of asturias spain shows alternation of bioclastic and laminated burrowed intervals the original content of carbonate brought by storms from shallow areas was larger in the bioclastic horizons however there is a widespread mismatch between facies alternations and the observed lithological rhythms the diagenetic redistribution of caco3 resulted in successive limestone marl clay couplets that do not match either in number or in the location of the boundaries the sedimentary cycles defined by facies alternations we conclude that interpreting the limestone marl rhythms as a direct response to primary changes is highly questionable unless there is unequivocal proof of a sedimentary origin of the alternation of the two lithologies

an inverse technique for developing models for fluid flow in fracture systems using simulated annealing one of the characteristics of flow and transport in fractured rock is that the flow may be largely confined to a poorly connected network of fractures in order to represent this condition lawrence berkeley laboratory has been developing a new type of fracture hydrology model called an equivalent discontinuum model in this model we represent the discontinuous nature of the problem through flow on a partially filled lattice this is done through a statistical inverse technique called simulated annealing the fracture network model is annealed by continually modifying a base model or template so that with each modification the model behaves more and more like the observed system this template is constructed using geological and geophysical data to identify the regions that possibly conduct fluid and the probable orientations of channels that conduct fluid in order to see how the simulated annealing algorithm works we have developed a synthetic case in this case the geometry of the fracture network is completely known so that the results of annealing to steady state data can be evaluated absolutely we also analyze field data from the migration experiment at the grimsel rock laboratory in switzerland

the propagation of tsunami generated acoustic gravity waves in the atmosphere abstracttsunami generated acoustic gravity waves have been observed to propagate in the atmosphere up to the ionosphere where they have an impact on the total electron content the authors simulate numerically the propagation of two dimensional linear acoustic gravity waves in an atmosphere with vertically varying stratification and horizontal background winds the authors goal is to compare the difference in how much energy reaches the lower ionosphere up to an altitude of 180 km where the atmosphere is assumed to be anelastic or fully compressible the authors consider three specific atmospheric cases a uniformly stratified atmosphere without winds an idealized case with a wind jet and a realistic case with an atmospheric profile corresponding to the 2004 sumatra tsunami results show that for the last two cases the number and height of turning points are different for the anelastic and compressible assumptions and the net result is that compressibility enhances the total transmission of energy

resonance in hawaii waters from the 2006 kuril islands tsunami 1 the 2006 kuril islands tsunami while not destructive to coastal properties resulted in prolonged oscillations in hawaii waters this study examines the oscillation patterns and amplification through reconstruction of the tsunami using a nonlinear shallow water model after validation with water level measurements a fast fourier transform of the computed surface elevation reveals profound oscillation modes at various periods around the hawaiian islands the oscillation at the regional scale consists of standing waves across the island chain and resonance in interconnected channels embayments and shallow shelves resonance in embayments and standing edge waves dominate the oscillation in coastal waters the results show strong correlation between bathymetric features and resonance oscillations and identify tsunami hazard areas for planning and emergency management

detection of tsunami driven phase and amplitude perturbations of subionospheric vlf signals following the 2010 chile earthquake we report on specific fluctuations in phase and amplitude of vlf signals that correlate both spatially and temporally with the passage of the tsunamis recorded by the deep ocean assessments and reporting of tsunamis bottom pressure stations measurements from the vlf lf receiver sited in petropavlovsk kamchatsky and sensor buoys placed throughout the pacific ocean at great distances hawaii and japan from the epicenter are consistent with the hypothesis that the ocean tsunami following the chile earthquake on 27 february 2010 radiated internal gravity waves which propagated through the lower ionosphere

cyclostratigraphy and the early jurassic timescale data from the belemnite marls dorset southern england time series based on determinations wt of calcium carbonate and total organic carbon have been generated for the entire lower jurassic hemipelagic belemnite marls dorset southern britain this formation was deposited during early pliensbachian time at a paleolatitude of about 35 n in an epicontinental sea that was largely enclosed by the supercontinent of pangea the sequence contains compositionally diverse light and dark marl bedding couplets the thicknesses of which are notably reduced in the upper third of the section the regularity of the couplets in segments of the sequence combined with a regular amplitude modulation indicates an origin that is related to the orbital precession cycle i e one of the milankovitch parameters a timescale is developed by assigning a duration of 20 k y per couplet and this suggests that the entire formation represents at least 1 78 m y using the new timescale bundles of bedding couplets are shown to have periods consistent with the 123 k y component of the orbital eccentricity variations the amplitude of the couplets varies at the same frequencies as the bundle cycles in accordance with the interpretation that the couplets record precession and the bundles record eccentricity however despite having the same frequency of variation there is no consistent relationship coherence between the variations in amplitude of the couplet cycle and the bundle cycles as would be predicted by the eccentricity precession relationship this mismatch can be explained in terms of nonlinear behavior of a climatic system characterized by a varying response time or nonlinear response of the sedimentary system itself the data contain no evidence for orbital obliquity cycles because the obliquity cycle affects insolation principally at high latitudes the climatic factors that indirectly controlled the sedimentary cyclicity must have arisen at relatively low latitudes the belemnite marls timescale indicates highly variable minimum durations for ammonite zones and subzones true durations cannot be determined because it is possible that the succession is incomplete as a result of undetected erosion and or nondeposition a combination of the new results with cyclostratigraphic data from yorkshire northeast england and the southern alps switzerland indicates based on cycle counts that the pliensbachian stage lasted at least 4 82 m y marine sr isotope ratios appear to have decreased linearly from the start of jurassic time until the end of pliensbachian time the rate of decrease in 87 sr 86 sr established using the belemnite marls timescale was 0 000042 m y or less if the main part of the formation is incomplete using this rate with the observed changes in sr isotope ratios gives minimum durations of 2 86 m y for hettangian time 7 62 m y for sinemurian time and 6 67 m y for pliensbachian time

ionospheric detection and localization of volcano eruptions on the example of the april 2015 calbuco events using data from ground based gnss receivers located in southern chile we study the ionospheric total electron content tec response to two eruptions of the calbuco volcano that occurred on 22 23 april 2015 in both cases the tec response showed quasi periodic signals with several consecutive wave trains the averaged amplitude of the observed co volcanic tec perturbations amounted 0 45 tecu for the first eruption and 0 16 tecu for the second one we compare amplitudes of the tec response to volcano eruptions of different intensity from our and previously published data and we show that both the intensity and the background ionospheric conditions define the amplitude of ionospheric co volcanic disturbances cvid the relative contribution however scales with the eruption intensity the travel time diagrams allowed to estimate the propagation speed of the observed co volcanic tec perturbations as 900 1200 m s which is close to the acoustic or shock acoustic waves speed at the ionospheric height the spectrograms are consistent with the conclusion on the acoustic nature of the observed tec perturbations finally we use the approximation of a spherical wave propagating at a constant velocity from a point source and for the first time we calculate the location of the volcanic source and the onset time of the volcano eruption from ionospheric measurements we show that even from 30 sec ionospheric gps data it is possible to localize the eruptive source within several degrees of latitude longitude

paleotemperature variations of early jurassic seawater recorded in geochemical trends of belemnites from the basque cantabrian basin northern spain abstract here we present new o isotope mg ca and sr ca data of early jurassic belemnites from the basque cantabrian basin of northern spain a succession deposited in a periodically anoxic restricted hemipelagic basin nearly 200 pliensbachian lower toarcian belemnites were collected and examined using optical cathodoluminescence and chemical techniques to constrain the effects of potential diagenetic alteration after a precise diagenetic screening of samples 176 belemnites were selected to provide records of changes in seawater geochemistry and temperature the records show a fairly good correlation of 18o with mg ca ratios r 0 65 and a weak correlation of 18o with sr ca ratios r 0 34 the oxygen isotope data if interpreted in terms of paleotemperature have revealed a period of relatively uniform and warm seawater temperatures during the early pliensbachian followed by a sharp temperature drop during the late pliensbachian earliest toarcian the onset of this cooler period occurred within the protogrammoceras celebratum subzone and the coolest seawater temperatures were reached at the end pliensbachian pleuroceras spinatum zone this was followed by a rapid seawater warming during the harpoceras serpentinus zone of the early toarcian in addition the data set provides new information regarding paleoceanographic conditions for anoxic events in a critical region of connection between the boreal and tethys realms it is the background to relatively high 18o values that prevailed during the anoxic episodes concerning the impact of the early toarcian anoxic event in northern spain the detected 18o and mg ca excursions reached their minimum and maximum respectively during the lower h serpentinus zone while the anoxic black shale interval developed earlier during the upper dactylioceras tenuicostatum lowermost h serpentinus zones

ionospheric disturbances induced by a missile launched from north korea on 12 december 2012 1 ionospheric disturbances caused by a missile launched from north korea on 12 december 2012 were investigated by using the gps total electron content tec the spatial characteristic of the front edge of v shaped disturbances produced by missiles and rockets was first determined considering the launch direction and the height of estimated ionospheric points at which gps radio signal pierces the ionosphere the missile passed through the ionosphere at heights of 391 425 and 435 km at 0056 30 0057 00 and 0057 30 ut respectively the observed velocities of the missile were 2 8 and 3 2 km s at that time which was estimated from the traveling speed of the front edge of v shaped disturbances westward and eastward v shaped disturbances propagated at 1 8 2 6 km s the phase velocities of the westward and eastward v shaped disturbances were much faster than the speed of acoustic waves reported in previous studies suggesting that sources other than acoustic waves may have played an important role furthermore the plasma density depletion that is often observed following missile and rocket launches was not found this suggests that the depletion resulting from the missile s exhaust was not strong enough to be observed in the tec distribution in the topside ionosphere