present day kinematics of the mediterranean a comprehensive overview of gps results i combine recently published gps results to derive a geodetic horizontal velocity field consistent at the scale of the mediterranean and the surrounding alpine belts the velocity field is then used to discuss the boundary conditions around each major deforming area in the mediterranean to describe the main patterns of motion and deformation to critically review the existing kinematics models and to finally point out the main unresolved kinematics questions strain rate in europe north of the alpines belt is dominated by the signature of the glacial isostatic adjustment and tectonic strain remains below the current accuracy of gps results in the western mediterranean deformation is restricted to the betics the alboran and the morrocan rif with west to southwestward motion with respect to iberia which is part of stable europe shortening consistent with the relative nubia eurasia plate motion is found throughout the maghrebides but the distribution of deformation in northern africa remains largely unknown the central mediterranean is dominated by the counter clockwise rotation of the adriatic the junction between the southern adriatic domain and nubia has yet to be firmly established the deformation over a wide area east of the maghrebides in tunisia and the gulf of sirte in libya still remains to be quantified in the eastern mediterranean the velocity field is dominated by a general anti clockwise rotation and a general trend towards the hellenic trench with velocity magnitude increasing with decreasing distances from the trench this trend is observed not only in the aegean and anatolia but also in the southern balkans geodetic results emphasize that the convergence of the nubia and arabia plates towards eurasia directly controls the deformation across only very few segments along the plate boundary zone additional processes are therefore required to explain the observed velocity field and deformation pattern

first paleoseismological constraints on the strongest earthquake in france provence in the twentieth century we have identified surface ruptures of m 6 earthquakes on a branch of the propagating reverse fault system that produced the strongest event recorded in france during the twentieth century 1909 lambesc earthquake provence the rate of slip on that branch is 0 05 0 3 mm yr with a corresponding return period for m 6 events of 700 5000 yr in addition to possibly identifying the 1909 earthquake surface rupture by recognizing successive surface breaks of large earthquakes this study calls for a reassessment of seismic hazard in provence

vertical sequence and lateral transitions in the facies of a barred nearshore environment abstract nine tube cores 7 cm in diameter and up to 150 cm long from a nearshore crescentic bar in kouchibouguac bay new brunswick canada reveal the vertical sequence and lateral transitions of facies previously identified only in shallow box cores the facies are a inner shelf shoreface transition bioturbated fine sands and silts with remnant primary structures b seaward slope planar lamination in medium to fine sands dipping gently seaward and composite bed sets of planar to ripple cross lamination in fine sand chevron lamination is rare c bar crest low angle planar lamination dipping both landward and seaward and medium scale trough cross lamination in medium to coarse sands d landward slope planar lamination dipping landward with small scale la dward dipping trough cross lamination occasionally small to medium scale trough cross lamination is found with seaward dips e trough massively bedded lags of coarse gravelly sands with abundant shell fragments contrast with isolated very thin units of massive silt and units of well sorted sands the latter display subhorizontal planar lamination and small to medium scale trough cross lamination polymodal dips indicate bed form migration landward alongshore and offshore vertical sequences and lateral transitions seaward of the bar crest suggest that three wedge shaped units inner shelf shoreface transition seaward slope bar crest interdigitate in an offlap onlap sequence to landward the trough and landward slope facies interfinger complexly while the crest facies forms a simple onlap over landward slope facies total reworking of sediments within the bar trough system is expected every 5 to 6 years and long term preservation is limited to the inner shelf shoreface transition seaward slope and trough facies

offset rivers drainage spacing and the record of strike slip faulting the kuh banan fault iran abstract this study concerns the ways in which rivers can record part but not necessarily all of strike slip fault offset the focus is the active right lateral kuh banan fault in eastern iran within the arabia eurasia collision plate convergence has caused thrust and strike slip faulting across sw asia the active slip rate of the kuh banan fault is 1 2 mm yr total displacement is 5 7 km as determined from offset geological markers and the length of a pull apart basin a component of thrusting has generated 1 km of relief which preserves the offset of rivers displaced laterally by the strike slip motion ridge half widths w and river outlet spacings along the fault s are related by the drainage spacing parameter r where r w s published data for older larger mountain ranges have extremely characteristic drainage spacing r 2 1 drainage spacing along the kuh banan fault has a mean value of 1 8 and is much more variable r 1 1 3 1 due to local structural complexities which have influenced river courses most river offsets along the kuh banan fault are small

inversion of field data in fault tectonics to obtain the regional stress iii a new rapid direct inversion method by analytical means summary a new method for determining the reduced stress tensor with four degrees of freedom the orientations of the three principal stress axes as well as the ratio of principal stress differences using fault slip data or focal mechanisms of earthquakes is presented from a computational point of view the inversion of fault slip data is made in a direct way by purely analytical means as a result the determination process is extremely fast and adaptable on small microcomputers from a physical point of view the method aims at simultaneously i minimizing the angles between theoretical shear stress and actual slip vector and ii having relative magnitudes of shear stress large enough to induce slip despite rock cohesion and friction examples of application to actual fault slip data sets with good or poor variety of fault slip orientations are shown the double significance of the basic criterion adopted results in a more realistic solution of the inverse problem than the single minimization of the shear stria angle

characteristic slip for five great earthquakes along the fuyun fault in china the seismic hazard associated with an individual fault can be assessed from the distributions of slip and recurrence times of earthquakes however seismic cycle models 1 that aim to predict rupture lengths and fault displacements of successive earthquakes on one fault remain poorly validated it is therefore unknown whether individual fault segments rupture independently producing earthquakes with a diverse range of magnitudes and recurrence times or slip by characteristic amounts with characteristic magnitudes here we use highresolution satellite data to document the horizontal offsets of stream channels and terraces created by strike slip motion on the fuyun fault xinjiang china during five historical earthquakes we find that the ms 7 9 11 august 1931 earthquake produced a surface rupture with a length of 160 km dispersed over three different fault segments the 290 measured stream channel and terrace offsets record an average slip of 6 3 m we use the degree of preservation of geomorphological markers to assign relative ages to individual fault offsets and identify at least four distinct older earthquakes we find that these older earthquakes also produced fault offsets with a similar distribution to the 1931 earthquake as the slip distributions during five successive earthquakes were so similar we conclude that ruptures on the fuyun fault obey a characteristic slip model very few large earthquakes are known to have ruptured the same fault segment twice in historical or instrumental time 1 the

palaeostress determinations from fault kinematics application to the neotectonics of the himalayas tibet and the central andes this paper concerns the determination of the stress deviator from a set of striated faults or of focal mechanisms of earthquakes southern tibet and the cuzco region of the high andes illustrate the applied methodology then the spatial and temporal changes in the tectonic regimes of tibet and central andes are briefly examined the quaternary present day stress patterns in these two high plateaus favour models explaining the spatial changes in the state of stress at a large wavelength as a result of a compensated elevated topography major temporal changes in the tectonic regimes are attributed tentatively to uplift for the tibetan plateau and for the already elevated andean plateau to changes in the magnitude of the boundary forces due to subduction processes

constraining recent fault offsets with statistical and geometrical methods example from the jasneuf fault western alps france we propose two new approaches regarding recent fault offset measurements by studying the seismogenic potential of the jasneuf fault the ne trending right lateral strike slip jasneuf fault is the southwestern extension of the belledonne fault system in the vercors massif this fault which is located in an intraplate domain does not show strongly associated seismicity but displays morphological anomalies that are related to recent faulting right lateral offset of late cenozoic cliffs recent talwegs and post ganz scarps the two methods that we use to quantify fault slip are as follows 1 recursive measurements of stream offsets are conducted this analysis reveals that a stream network can display characteristic distances between streams that can be mistakenly interpreted as long term cumulative fault offsets a comparison of the apparent stream offset values and stream spacing values is necessary to identify the true offsets 2 we propose a new method that enables us to determine the fault offset and kinematics by using recursive measurements of topographic apparent offsets to counter the lack of morphologic features that are used to determine piercing points or lines this method enables us to define each possible slip vector for numerous artificial piercing points along a fault the slip vector that is shared by these piercing points is the true slip vector by applying these methodologies we determine that the jasneuf fault has accumulated slip since the messinian which corresponds to an average slip rate of 0 13 0 03 mm year the extension of the fault is poorly constrained nevertheless if we do not consider the potential aseismic creep slip component of the faulting we calculate that this fault could generate mw 5 7 earthquakes every similar to 500 years according to wells and coppersmith s scaling laws and by assuming that the faulting is limited to the sedimentary cover and the vercors plateau c 2016 elsevier b v all rights reserved

sediment transport on dissipative intermediate and reflective beaches abstract in this paper we review and synthesize field measurements of suspended sediment transport on the shoreface of dissipative intermediate and reflective beach states the morphodynamic beach state continuum was originally established in the 1970s but at the time only hydrodynamic processes and morphologies in these various states were described since the early 1980s when sensors capable of resolving suspended sediment concentration at intra wave time scale became available many studies have examined suspended sediment transport by waves and currents on the shoreface the synthesis of this work shows that the two end states in the morphodynamic continuum which are the dissipative and reflective states exhibit relatively small rates of cross shore sediment transport and weak gradients in that transport which both ensure that the nearshore morphology is relatively stable the intervening intermediate beach states typically exhibit prominent bar topographies and in these states strong morphodynamic feedbacks between hydrodynamic processes and morphology create locally large transport rates and sharp transport gradients which is the reason for the dynamic nature of these beach states transport processes driving sediment onshore and offshore within beach states are discussed as well as the transport processes responsible for state transitions

new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

interannual evolution of multiple longshore sand bars in a mesotidal environment truro massachusetts usa abstract multiple longshore bars 0 30 1 5 m in amplitude are present in the nearshore zone off truro ma in cape cod bay these bars exist in a mesotidal environment with a tidal range of 3 0 m a detailed interannual investigation of these bars over a 16 year time period using orthorectified vertical aerial photography has been carried out to characterize the behavior of multiple bars forming in a mesotidal environment over a temporal scale of observation not generally achieved by direct field study this investigation reveals that the bars are dynamic over the time interval studied with offshore extents of up to 660 m and wavelengths of 45 150 m generally increasing in the seaward direction at any one location 4 to 10 bars are present with an apparent addition of bars at the southern end of the study area in addition the bars are consistently parallel to offshore bathymetric contours and comparison of more recent photographs with a 1960 image reveals a 0 5 km alongshore zone without bars that has persisted and grown since 1960 the characteristics of the truro multiple bar field are consistent with several existing theories of multiple bar formation including formation by breaking waves standing infragravity waves and edge waves the demonstrated dynamic nature of the truro multiple bar field over a long temporal scale suggests that field experiments designed to distinguish between possible formation theories may provide an explanation for the continuing modern creation and modification of this and similar multiple bar fields occurring in mesotidal environments

observations of sand bar evolution on a natural beach waves currents and the location of the seafloor were measured on a barred beach for about 2 months at nine locations along a cross shore transect extending 255 m from 1 to 4 m water depth the seafloor location was measured nearly continuously even in the surf zone during storms with sonar altimeters mounted on fixed frames the crest of a sand bar initially located about 60 m from the shoreline moved 130 m offshore primarily when the offshore significant wave height exceeded about 2 m with 1 5 m of erosion near the initial location and 1 m of accretion at the final location an energetics type sediment transport model driven by locally measured near bottom currents predicts the observed offshore bar migration but not the slow onshore migration observed during low energy wave conditions the predicted offshore bar migration is driven primarily by cross shore gradients in predicted suspended sediment transport associated with quasi steady near bottom offshore flows these strong 50 cm s currents intensified near the bar crest by wave breaking are predicted to cause erosion on the shoreward slope of the bar and deposition on the seaward side the feedback amoung morphology waves circulation and sediment transport thus forces offshore bar migration during storms

storms shoreface morphodynamics sand supply and the accretion and erosion of coastal dune barriers in the southern north sea abstract the coast of the southern north sea is bound by dune barriers that have developed adjacent to a shallow storm and tide dominated shoreface comprising numerous shore parallel to sub shore parallel tidal sand banks the banks evolve under the joint control of tide wave and wind induced shore parallel currents which tend to stretch them eventually leading to bank division and to shoaling and breaking storm waves which tend to drive them ashore the banks thus modulate the delivery of storm wave energy to the coast redirect currents alongshore and are the sand sources for the accretion of coastal dunes foredune accretion occurs where major sand banks have migrated shoreward over the last centuries to be finally driven ashore and weld under the impact of storm waves morphological changes in the bank field can impact on shoreline stability through dissipation or enhanced shoreward transmission of storm wave energy and effects on radiation stress particularly when waves are breaking over the banks where banks are close to the shore mitigation of offshore sediment transport especially during storms can occur because of gradients in radiation stress generated by the complex 3d bank structure these macro scale mechanisms involve embedded meso scale interactions that revolve around the mobility of sand waves mobility of beach bars and troughs and foredune mobility and micro scale processes of bedform mobility in the subaqueous and intertidal domains and of swash and aeolian beach dune sand transport these embedded interactions and the morphodynamic feedback loops illustrate the importance of synchroneity of sand transport from shoreface to dune on this coast large stretches of the foredunes show either signs of stability or mild but chronic erosion furthermore a demonstrated lack of a clear relationship occurs between storminess and coastal response over the second half of the 20th century the present situation may be indicative of conditions of rather limited sand supply from offshore notwithstanding the abundance of sand on the nearby shallow shoreface except in areas where a nearshore storm driven tidal sand bank has become shore attached apart from the important influence of shoreface sand banks and of wave bank interactions foredune accretion and erosion also depend on various context controls that include individual storm characteristics wind speed and incidence relative to the shore tidal stage during storms and direct human intervention on the shore through foredune and beach management the bewildering variability inherent in these intricately related parameters may also explain the poor relationship between storminess and barrier shoreline change and will still continue to render unpredictable the response of shores to individual storms

between beds and sequences stratigraphic organization at intermediate scales in the quaternary of the virginia coast usa stratigraphy presupposes a hierarchy of scales of spatial organization supplemented at the small scale end by sedimentological concepts beds bed sets and bed cosets and at larger spatial scales by sequence stratigraphic concepts systems tracts parasequences sequences between these two end members are intermediate sclae bodies described as lithofacies or simply facies a more restricted concept granulometric facies can be described in terms of horizontal grain size gradients facies change and cvclic vertical grain size gradients stratification assemblages of facies so defined also called depositional systems are not random loot occur in a limited suite of patterns such assemblages may be linked to two classes of bounding surfaces a source diastem the immediate source of the sediment and a surface of closure if preserved between which is sandwiched a transgressive or regressive basinward fining facies succession systems bounding surfaces are notably more continuous than internal gradational facies boundaries by thus restricting the definition of a facies assemblage depositional system it is possible to describe the quaternary of the virginia coast wish as few as 12 systems depositional systems in the quaternary of the virginia coast are allometric in that any system can be derived from any other by plastic expansion of one or more facies relative to another or by simple symmetry operations self similarity prevails across this intermediate scale of stratigraphic organization facies assemblages depositional systems consist of event beds which themselves have erosional basal boundaries and internal successions of microfacies at larger spatial so ales depositional systems are repeated either autocyclic repetitions forced by processes within the basin of deposition or allocyclic repetitions as parasequences and high frequency sequences in the virginia quaternary systems architecture is compatible with sequence architecture and nests conformably within its framework but analysis of systems architecture reveals rules beyond those governing sequence architecture

collision kinematics in the western external alps the kinematics of the collision in western alps are investigated through five balanced cross sections of the whole external domain from the oisans to the mont blanc massif these cross sections were built using published data for the jura and subalpine fold and thrust belts and new structural and field analysis for the external crystalline massifs five units are defined the sedimentary nappes from innermost parts of the external zone e g ultra dauphinois helvetic the crystalline units with their dysharmonically folded cover e g morcles nappe sedimentary nappes over the frontal parts of the crystalline massifs the aravis granier unit the subalpine belts e g vercors chartreuse bauges and bornes and the jura except for the ultra dauphinois nappes the shortening including the cover shortening always corresponds to basement shortening the total amount of shortening increases from south 28 km 20 to north 66 km 27 moreover the shortening is slightly older in the south than in the north deepwater turbidites flysch and shallow marine to freshwater clastics molasse basins are more developed in the north pressure and temperature conditions are higher in the north the average uplift rates are about 3 times higher in the north and more localized in space we propose that these differences are due to along strike variations in the structure of the european continental margin inherited from mesozoic times we then build five palinspastic maps one at cretaceous times showing the inherited european mesozoic margin structure and four from priabonian to upper miocene times showing the collision kinematics and the related rotation of adria

depositional architecture of a wave dominated clastic shoreline pilmatue member argentina linking dynamics and stratigraphic record of bar trough systems abstract bar trough morphologies are a dominant feature of modern wave dominated clastic shorelines despite these barred configurations being widely described from modern systems there is still some uncertainties associated with their interpretation in the ancient record there is a lack of detailed outcrop based studies describing the facies distribution and architecture within bar trough systems which causes a disparity between observations of modern processes and the subsequent preserved rock record this work presents a detailed characterization and interpretation of the sedimentary record of a bar trough setting this was achieved through the analysis of nearshore i e upper shoreface and foreshore deposits within a parasequence in the lower cretaceous pilmatue member of the agrio formation neuquen basin argentina a high resolution facies and architectural analysis was developed combining detailed sedimentary logs with the mapping of bounding and internal surfaces within the nearshore deposits the facies analysis suggests that trough and planar cross bedded facies are remnants of dunes in the upper shoreface due to a strong influence of longshore currents while planar laminated facies would be the result of swash processes in the foreshore additionally the presence of a well defined surf diastem the persistent low angle obliquity of palaeocurrents and the preservation of concave upward stratigraphic surfaces led to the interpretation of those deposits as representing the production of a bar trough configuration with longshore currents distributing large amounts of sediment along the shore this analysis allowed us to reconstruct the dominant processes for sediment transport and deposition within these barred nearshore settings and to identify different key architectural surfaces for the upper shoreface and foreshore deposits the architectural analysis of such surfaces led to define four different orders of hierarchy which respond to depositional and erosional processes operating at different scales the comparison between different resulting architectures of wave dominated barred shoreline offers the possibility to improve in the palaeoenvironmental reconstructions for ancient or recent successions the proposed model for bar trough clastic shoreline successions relates an absence of bar related deposits to major storms and shoreline erosional processes this conceptual model offers a new interpretation for explaining the mid scale evolution of bar trough settings and the relationship between the modern and ancient record

geodetic measurements of crustal deformation in the western mediterranean and europe geodetic measurements of crustal deformation over large areas deforming at slow rates 5 mm yr over more than 1000 km such as the western mediterranean and western europe are still a challenge because 1 these rates are close to the current resolution of the geodetic techniques 2 inaccuracies in the reference frame implementation may be on the same order as the tectonic velocities we present a new velocity field for western europe and the western mediterranean derived from a rigorous combination of 1 a selection of sites from the itrf2000 solution 2 a subset of sites from the european permanent gps network solution 3 a solution of the french national geodetic permanent gps network rgp and 4 a solution of a permanent gps network in the western alps regal the resulting velocity field describes horizontal crustal motion at 64 sites in western europe with an accuracy on the order of 1 mm yr or better its analysis shows that central europe behaves rigidly at a 0 4 mm yr level and can therefore be used to define a stable europe reference frame in that reference frame we find that most of europe including areas west of the rhine graben the iberian peninsula the ligurian basin and the corsica sardinian block behaves rigidly at a 0 5 mm yr level in a second step we map recently published geodetic results in the reference frame previously defined geodetic data confirm a counterclockwise rotation of the adriatic microplate with respect to stable europe that appears to control the strain pattern along its boundaries active deformation in the alps apennines and dinarides is probably driven by the independent motion of the adriatic plate rather than by the africa eurasia convergence the analysis of a global gps solution and recently published new estimates for the african plate kinematics indicate that the africa eurasia plate motion may be significantly different from the nuvel1a values in particular geodetic solutions show that the convergence rate between africa and stable europe may be 30 60 slower than the nuvelia prediction and rotated 10 30 counterclockwise in the mediterranean

nearshore sandbar migration field observations suggest that onshore sandbar migration observed when breaking wave driven mean flows are weak may be related to the skewed fluid accelerations associated with the orbital velocities of nonlinear surface waves large accelerations both increases and decreases in velocity magnitudes previously suggested to increase sediment suspension occur under the steep wave faces that immediately precede the maximum onshore directed orbital velocities weaker accelerations occur under the gently sloping rear wave faces that precede the maximum offshore directed velocities the timing of strong accelerations relative to onshore flow is hypothesized to produce net onshore sediment transport the observed acceleration skewness a measure of the difference in the magnitudes of accelerations under the front and rear wave faces is maximum near the sandbar crest the corresponding cross shore gradients of an acceleration related onshore sediment transport would cause erosion offshore and accretion onshore of the bar crest consistent with the observed onshore migration of the bar crest furthermore the observations and numerical simulations of nonlinear shallow water waves show that the region of strongly skewed accelerations moves shoreward with the bar suggesting that feedback between waves and evolving morphology can result in continuing onshore bar migration

sedimentology and morphodynamics of a barrier island shoreface related to engineering concerns outer banks nc usa abstract forty nine vibracores were collected from a barrier island shoreface following 12 4 years of biweekly profile surveying the sedimentologic architecture of the shoreface was linked to time series elevation change and profile shape to determine relationships between morphodynamics facies development erosional processes profile closeout and cross shore transport the modern shoreface mass which erosionally overlies a tidal inlet associated complex attains a maximum thickness of 3 4 m below the beach to middle profile before pinching out seaward between 9 and 12 m depth concave erosional surfaces overlain by cross stratified fine to medium sand and gravel make up most of the lower half of the shoreface prism below the beach through middle profile reflecting longshore trough incision and subsequent current dominated aggradation at the landward margin gravel rich laminae record episodic seaward progradation of beach surfaces over coarse inner trough settings seaward a parallel laminated fine sand facies dominates the upper part of the prism recording intermittent shoal zone buildup including trough filling under high velocity plane bed conditions similarly a bioturbated parallel laminated fine to very fine sand facies makes up the entire prism below the outermost lower ramp sector again indicating buildup under high velocity conditions however accretion of the lower ramp results from major storms that cause trough scour along landward locations and simultaneous displacement of fine sand onto the lower ramp conversely lower ramp erosion typically occurs during less energetic conditions as sediment is slowly returned shoreward causing inner shoreface buildup close spacing of major storms during some years led to net progradation of the shoreface the upper and lower limits of surveyed elevation change ule and lle repeatedly develop similar limit profile shapes over shoreface accretion erosion cycles the ule reflects accretion maxima resulting from beach bar and lower ramp buildup the lle and lower sedimentologic limit lls along the inner 250 to 300 m of the active shoreface are a product of storm trough scour down to a maximum depth of 5 5 m below the lower ramp facies the lle and lls are primarily products of less energetic wave erosion down to 5 m shoreward and 9 m offshore depths the lle closely matches the lls documenting that 90 of the shoreface prism was reworked during the 12 4 year period whereas actual ages for erosional events indicate a potential of 2 to 4 years for complete reworking of the shoreface mass textural distribution indicates net long term transport direction and loci of deposition for different sized material the coarsest material is concentrated at landwardmost locations and well sorted fine to very fine sand at seaward locations medium sand to gravel tends to remain within the trough zone even during extreme storm events the ule and lle also represent the upper and lower limits for profile closure events a location of about 4 5 m depth at 300 to 350 m from shoreline marks the boundary between inner profile and lower ramp associated closure events the boundary between trough associated and lower ramp facies and the lower ramp morphologic break all of which correspond to the juncture between longshore current and shoaling wave dominated zones the lower ramp zone of closure is a zone of seaward decreasing storm transport in which fine to very fine sand is the typical bedload material

offsets of late quaternary morphology rate of slip and recurrence of large earthquakes on the chang ma fault gansu china the chang ma fault in the western qilian shan gansu province shows evidence of consistent left lateral displacements despite a complex en echelon geometry we have measured short and long term offsets on two n70 80 e striking segments of the fault along the southern edge of the ta quen kou basin where it cuts late quaternary terraces transverse ridges and drainage channels to analyze the offsets of such structures at one site in the eastern part of the basin we ran topographic profiles parallel and perpendicular to the fault over a distance of about 5 km spectral analysis and comparison of longitudinal profiles north and south of the fault allowed us to separate horizontal offsets of structures of different wavelengths apparent on air photos and satellite images transverse profiles were used to determine the vertical throw whose variations appear to result from changes in the fault strike small horizontal offsets of ridge crests and valley slopes are about 55 m along the n70 e striking segment of the fault this displacement corresponds to an uplift of the northern block of about 27 m implying that the fault dips about 73 to the south the measurements also constrain horizontal projection of the slip vector to about n78 e a larger horizontal offset 500 m of morphological swells of longer wavelength 1 6 km is visible on the longitudinal profiles assuming that periglacial erosion has reshaped the surface of the lateral slopes and tops of ridges during the wurm glacial period the smallest offsets of adjacent ridge crests may postdate the begining of the holocene yielding an average rate of left lateral slip on the fault of 5 5 2 2 mm yr in the last 10 2 kyr in the western part of the ta quen kou basin a somewhat slower rate of holocene slip 4 6 4 mm yr is obtained measurement of the horizontal displacement due to the 1932 earthquake there 6 2 0 6 m would imply that the recurrence interval for similar earthquakes at this second site is 1350 540 years

an inverse method for determining three dimensional fault geometry with thread criterion application to strike slip and thrust faults western alps and california abstract in order to draw geological structures such as faults interpolation is generally needed between scattered data the use of an approximation criterion integrating the kinematic properties of the faults helps to document the fault surfaces by adding a compatibility criterion to the data set assuming that two jointed blocks of rocks slipping on each other generate a thread surface an approximation method has been developed which integrates a thread criterion this approximation method is used to solve an inverse problem with least squares criteria including proximity to data points smoothness and thread criteria the aim is to find a smooth surface which is as close as possible to a thread and as close as possible to the observed data set applications to two corrugated fault surfaces with a dense data set located in the western alps france and in the transverse ranges california confirm the validity of the thread assumption despite their difference in mean corrugation wavelength 5 m and 10 km respectively in the type of fault strike slip and thrust fault respectively and in the nature of the faulted rocks limestones and sandstones respectively very similar results are obtained in both cases the observed data fit well with a thread surface and the computed fault displacement fits well with the measured displacement on the fault striae seismic focal mechanism geodetic data restoration the conclusion is that treating a fault as a thread is a valid physical description which gives the slip direction independently of other kinematic indicators the advantage of using a thread criterion in addition to classical proximity and smoothness criteria is that this physical insight allows information from areas where data are relatively dense to help constrain areas where data are relatively sparse these last areas being those that are usually not well constrained by proximity and smoothness criteria

sediment flux and equilibrium slopes in a barred nearshore estimates of time integrated values of total itvf and net invf sediment volume flux and the associated changes in bed elevation and local slope were determined for a crescentic outer nearshore bar in kouchibouguac bay new brunswick canada for eight discrete storm events a 100 150 m grid of depth of activity rods spaced at 10 m intervals was used to monitor sediment behaviour on the seaward slope bar crest and landward slope during the storms at which time winds incident waves and near bed oscillatory currents were measured comparisons between storm events and between these events and a longer term synthetic wave climatology were facilitated using hindcast wave parameters strong positive correlations between storm wave conditions significant height and total cumulative energy and total volume flux contrasted strongly with the zero correlation between storm wave conditions and net volume flux itvf values ranged up to 1646 m3 for the experimental grid and were found to have power function relations with significant wave height exponent 2 and cumulative wave energy exponent 0 4 values of invf ranged from 0 up to 100 m3 for the same grid indicating a balance of sediment volume in the bar form through time sediment reactivation increased linearly with decreasing depth across the seaward slope and bar crest reaching maxima of 20 cm for the two largest storms bed elevation and thus slope changes were restricted to the bar crest and upper landward slope with near zero morphological change on the seaward slope the latter represents a steady state equilibrium with null net transport of sediment under shoaling waves measurements of the asymmetry of orbital velocities close to the bed show that the energetics approach to predicting beach slope of inman and bagnold 1963 is sound gradients predicted vary from 0 01 to 0 03 for a range of angles of internal friction appropriate to the local sediment tan o 0 3 0 6 these compare favorably with the measured seaward slope of 0 015 formed under average maximum orbital velocities of 1 12 m s 1 landward and 1 09 m s 1 seaward recorded during the period of the largest storm waves

mechanisms of margin inversion in the external western alps implications for crustal rheology the kinematics of the collisional crustal wedge in the external western alps is discussed in the light of new cross sections of the whole external zone at the latitude of the belledonne grandes rousses oisans massifs external crystalline massifs ecm as well as a detailed analysis of the deformation of their basement and cover the cross sections were built from new field data and published geological maps and were restored through time oligo miocene times to unravel the successive stages of the dauphinois margin contractional deformation during oligocene times the variscan basement was deformed essentially by greenschist facies alpine distributed shear zones with no significant reactivation of the inherited jurassic normal faults or the variscan foliation however the inherited syn rift basins localized the deformation characterized by a thick skinned style and a cover disharmonically folded over basement shear zones with no major decollement in between shortening of 11 5 km 20 those early deformations progressively localized on the frontal crustal ramp and caused shortening in the folded belt 16 5 km of shortening 23 a similar sequence of deformation has been inferred in other alpine ecms this strongly suggests that the crust of dauphinois proximal passive margin was thin enough and its buoyancy low enough as a result of the liassic rifting to experience significant tectonic burial during the tertiary collision as a consequence of a weakening by both the presence of inherited basins and their weak syn rift sediments and the p t conditions greenschist facies the crust was shortened and the structural style was thick skinned

profile response of a lacustrine multiple barred nearshore to a sequence of storm events profile change in a lacustrine multiple barred nearshore was investigated over the ice free season of 2001 2002 at burley beach on the southeastern shore of lake huron in order to identify the feedback mechanisms between the pre existing morphology and the wave forcing and the consequence of those feedbacks to the behaviour of the nearshore environment the characteristics of the offshore wave field were monitored using a falmouth scientific combined 3d acm wave recorder and pressure transducer supplemental wave data were downloaded from a 3 m discus buoy operated by the national data buoy center 75 km to the nwof the study site the three nearshore bars were in a quasi equilibrium state through a large part of the ice free season with dramatic changes occurring during relatively moderate storm events that followed much larger storms in late october a comparison of the incident wave field with changes in the nearshore profile through canonical correlation analysis indicates that the morphology responds to the distribution of the significant root mean square rms and average wave heights between surveys the threshold between bar decay and onshore bar migration and growth is associated with the onset of breaking of the rms wave at the bar crest hrms hcr 1 c0 3 0 4 the threshold between onshore and offshore migration is associated with the onset of breaking of the average wave at the bar crest havg hcr 1 c0 3 0 4 coincident with complete dissipation of the significant wave over the lakeward slope of the bar hs hcr 1 n0 6 inshore wave data collected during an instrumented study at the same site revealed that the middle and inner bars remained at the threshold of onshore and offshore migration over a wide range of offshore significant wave heights 0 8 to 2 4 m prior to the october storms this self organised equilibrium is a result of changes to the incident wave distribution through breaking on the outer bar it is concluded that the prediction of bar response requires an understanding of the feedback between the bar and the local wave distribution in addition to an understanding of the feedback associated with the profile as a whole d 2005 elsevier b v all rights reserved

tectonic and geomorphic analysis of the belledonne border fault and its extensions western alps in the western alps the ne trending belledonne fault system extends from the mont blanc massifs in the ne to the vercors massif in the sw it includes the belledonne border fault defined by an alignment of micro earthquakes ml 3 5 focal mechanisms and their respective depths indicate a crustal scale ne trending dextral strike slip faulting this study aims at better constraining the geometry the fault kinematics and slip rate of the faults of the belledonne fault system by using a multidisciplinary approach that includes tectonics geomorphology and geophysics new clues of potential quaternary deformations are observed 1 the right lateral offsets of morphologic markers talwegs along the ne trending arcalod fault at the north eastern termination of the belledonne border fault 2 the left lateral offset of the valley carved by the isere glacier along the nw trending brion fault which is consistent with the fault kinematics deduced from the focal mechanisms stream network anomalies along the belledonne border fault are related to glacial erosion processes rather than faulting however fault kinematics analysis along the belledonne border fault allows us to determine a strike slip tectonic regime characterized by horizontal ene trending sigma 1 stress axis it is consistent with the mean trend of the p and t axes deduced from the focal mechanisms we display evidences that this stress state is messinian to quaternary in age and occurred after an oligocene to messinian strike slip tectonic regime characterized by horizontal wnw trending sigma 1 fault slip rates cannot be assessed because of the lack of morphologic features with constrained ages however it is likely that the presented geomorphic markers are older than wurm c 2015 elsevier b v all rights reserved

plio quaternary stress states in ne iran kopeh dagh and allah dagh binalud mountain ranges abstract ne iran including the kopeh dagh and allah dagh binalud deformation domains comprises the northeastern boundary of the arabia eurasia collision zone this study focuses on the evolution of the plio quaternary tectonic regimes of northeast iran we present evidence for drastic temporal changes in the stress state by inversion of both geologically and seismically determined fault slip vectors the inversions of fault kinematics data reveal distinct temporal changes in states of stress during the plio quaternary since 5 ma the paleostress state is characterized by a regional transpressional tectonic regime with a mean n140 10 e trending horizontal maximum stress axis 1 the youngest modern state of stress shows two distinct strike slip and compressional tectonic regimes with a regional mean of n030 15 e trending horizontal 1 the change from the paleostress to modern stress states has occurred through an intermediate stress field characterized by a mean regional n trending 1 the inversion analysis of earthquake focal mechanisms reveals a homogeneous transpressional tectonic regime with a regional n023 5 e trending 1 the modern stress state deduced from the youngest fault kinematics data is in close agreement with the present day stress state given by the inversions of earthquake focal mechanisms according to our data and the deduced results in northeast iran the arabia eurasia convergence is taken up by strike slip faulting along ne trending left lateral and nnw trending right lateral faults as well as reverse to oblique slip reverse faulting along nw trending faults such a structural assemblage is involved in a mechanically compatible and homogeneous modern stress field this implies that no strain and or stress partitioning or systematic block rotations have occurred in the kopeh dagh and allah dagh binalud deformation domains the plio quaternary stress changes documented in this paper call into question the extrapolation of the present day seismic and gps derived deformation rates over geological time intervals encompassing tens of millions of years

coseismic slip vectors of 24 august and 30 october 2016 earthquakes in central italy oblique slip and regional kinematic implications after 24 august and 30 october 2016 central italy earthquakes mw 6 0 and 6 5 respectively photogrammetry and geodetic survey were performed at various sites along a 6 km long portion of the rupturing monte vettore fault system providing very high resolution georeferenced 3 d point clouds and imagery of the 24 august rupture and a data set of bedrock fault scarp before after the 30 october earthquake the maximum coseismic displacement for both events occurs near scoglio dell aquila with an average normal dip slip of 22 4 and 184 6 cm respectively coseismic slip vectors and meter scale corrugation axis are oriented n280 10 on the n140 striking main vettore fault involving oblique normal slip with a right lateral component and n205 10 on n170 fault strands implying oblique normal slip with a left lateral component we quantify the near field coseismic displacements of the monte vettore fault for the 30 october event the footwall has been translated horizontally by 42 2 cm toward the ene and uplifted by 11 2 cm the hangingwall has moved horizontally by 26 2 cm toward the nw in a direction parallel to the fault plane and subsided by 116 2 cm the fault geometry and our determined surface coseismic slip vectors are mechanically compatible with a 3 n65 15 this stress regime is consistent with the 30 october 2016 focal mechanism and the relative motion between the adriatic microplate and the tyrrhenian coastal region the 30 october surface rupture results from seismic slip at depth and thus has a tectonic origin

simulating infiltration into frozen prairie soils in streamflow models a major limitation of existing operational systems when applied to forecasting or synthesizing streamflow from snowmelt on watersheds in many pans of central and northern canada is that they are incapable of accurately simulating the process of infiltration into frozen soils the results and discussion in the paper provide a method of overcoming the problem in areas of climatic and physiographic conditions similar to those of the prairies details outlining the development of a model describing snowmelt infiltration into frozen soils are presented the model is based on the concept that for practical purposes the infiltration potential of frozen soils may be generally categorized as 1 restricted impervious 2 unlimited capable of infiltrating the snow cover water equivalent and 3 limited infiltration is governed by the snow cover water equivalent and the ice content of the soil at the time of melt an empirical relationship for calculating infiltration into frozen soils of limited potential is

intraplate seismicity new seismotectonic data in western europe abstract fault plane solutions for 128 earthquakes which occurred in france and neighbouring areas have been determined stress field information given by these data are discussed in relation to previous tectonic knowledge the western alps are characterized by a compressional regime with a fan shaped distribution of p axes which might be related to the interaction mechanism between europe and the adriatic plate the pyrenean region is mainly submitted to a south north compression tectonic activity in this area seems to be determined by the presence of two subduction zones with reverse dips in the south bay of biscay and in the central pyrenees the transition zone between these two active belts is characterized by significant seismicity with a transpression regime

slip in the 1857 and earlier large earthquakes along the carrizo plain san andreas fault the moment magnitude mw 7 9 fort tejon earthquake of 1857 with a 350 kilometer long surface rupture was the most recent major earthquake along the south central san andreas fault california based on previous measurements of its surface slip distribution rupture along the 60 kilometer long carrizo segment was thought to control the recurrence of 1857 like earthquakes new high resolution topographic data show that the average slip along the carrizo segment during the 1857 event was 5 3 1 4 meters eliminating the core assumption for a linkage between carrizo segment rupture and recurrence of major earthquakes along the south central san andreas fault earthquake slip along the carrizo segment may recur in earthquake clusters with cumulative slip of 5 meters

aseismic deformation in the alps gps vs seismic strain quantification neotectonics of the western and central alps is characterized by ongoing widespread extension in the highest zones of the chain and transcurrent compressive tectonics at the external limits of the belt the overall geodetically measured deformations also indicate extension across the western alps there is a good qualitative coherency between seismotectonic and geodetic approaches here we attempt to quantify the seismic part of the deformation the seismic strain is compared to the deformation derived from geodesy in sub areas of homogeneous seismic stress strain we computed the total seismic moment tensor and related strain tensor this study provides new quantitative elements about the ongoing geodynamic processes in the alpine belt the important discrepancies obtained between seismic strains and geodetically measured deformations raise the issue of aseismic deformation in the alps which could be related to elastic loading creeping and or a slower ductile style deformation

3d_fault_offsets a matlab code to automatically measure lateral and vertical fault offsets in topographic data application to san andreas owens valley and hope faults measuring fault offsets preserved at the ground surface is of primary importance to recover earthquake and long term slip distributions and understand fault mechanics the recent explosion of high resolution topographic data such as lidar and photogrammetric digital elevation models offers an unprecedented opportunity to measure dense collections of fault offsets we have developed a new matlab code 3d fault offsets to automate these measurements in topographic data 3d fault offsets mathematically identifies and represents nine of the most prominent geometric characteristics of common sublinear markers along faults especially strike slip in 3 d such as the streambed minimum elevation top free face and base of channel banks or scarps minimum laplacian maximum gradient and maximum laplacian and ridges maximum elevation by calculating best fit lines through the nine point clouds on either side of the fault the code computes the lateral and vertical offsets between the piercing points of these lines onto the fault plane providing nine lateral and nine vertical offset measures per marker through a monte carlo approach the code calculates the total uncertainty on each offset it then provides tools to statistically analyze the dense collection of measures and to reconstruct the prefaulted marker geometry in the horizontal and vertical planes we applied 3d fault offsets to remeasure previously published offsets across 88 markers on the san andreas owens valley and hope faults we obtained 5 454 lateral and vertical offset measures these automatic measures compare well to prior ones field and remote while their rich record provides new insights on the preservation of fault displacements in the morphology

ground penetrating radar profiles of holocene raised beach deposits in the kujukuri strand plain pacific coast of eastern japan abstract ground penetrating radar gpr profiles of holocene beach deposits were documented from the kujukuri strand plain pacific coast of japan to examine a marker of past sea level recognized in these profiles the kujukuri strand plain has been uplifted over the last 6000 years with a total relative sea level fall of about 5 m suggested by seaward lowering of the lithologic boundary between the foreshore and upper shoreface facies a gpr survey was performed on a modern aeolian dune and beach ridges of the strand plain using a pulseekko100 system with 100 mhz antennae the profiles obtained contain five vertically stacked radar units r1 r5 with characteristic reflections ground truthing using sediment cores and the morphology of the modern beach suggest that these radar units correspond to aeolian dune r1 small scale swale r2 backshore and foreshore r3 upper shoreface r4 and lower shoreface r5 deposits in descending order the backshore and foreshore radar unit shows a sequence of continuous reflections dipping seaward at an angle consistent with the modern beach whereas the underlying upper shoreface radar unit represents complicated and less continuous reflections the boundary between these two units is a downlap surface of the foreshore reflections and is thought to have formed at about 1 m below the mean sea level at the time of deposition the lateral tracing of the boundary in radar profiles across the strand plain indicates a total fall in relative sea level of 5 m which is consistent with the drill core results radar profiles of the foreshore and upper shoreface deposits in the kujukuri strand plain thus provide a past sea level indicator that is available without drilling sediment cores

flow regime and bedforms in a ridge and runnel system s e spain abstract during landward migration ridge and runnel systems are subjected to asymmetric oscillatory and or unidirectional flow regimes depending on the stage of development reached by these systems in the early stages of evolution when the ridge is situated in the upper shoreface the whole system is subjected to asymmetric oscillatory flow the runnel is under lower flow regime conditions and the ridge may be under upper or lower flow regime according to water depth and wave energy later when the ridge has migrated to a position on the foreshore the runnel is largely under a unidirectional lower flow regime while the ridge itself is under oscillatory upper flow regime when the ridge welds to berm it is largely emergent and exposed to high tide swash action under upper flow regime conditions the runnel is eventually filled with sand and transformed into a low lying area all these types grade laterally into each other one or more ridge and runnel systems can occur at the same time wave energy tide level and position of the ridge control the variations in the characteristics of the ridge and also the position of the zones of bedforms found at the upper shoreface

the effects of storm clustering on beach profile variability abstract impacts of storms in reshaping coastlines are well known also the far greater impact of clusters of storms where storms occur at close succession has been noted in a number of previous studies in this paper we analyse and discuss the storm wave climate and the beach profile response to clusters of storms at narrabeen beach new south wales australia narrabeen beach is subjected to frequent storms all year round and the beach undergoes substantial variability as a result the impact of storm clusters with closely spaced individual storms reaching the beach is investigated by combining historic measurements of beach profile surveys and numerical modelling of storm induced beach change our analysis of storm power index of storm clusters and its correlation with the change in beach width reveals that the strengths of single storms in a storm cluster alone are not the reason for beach change but time interval between successive storms and the post storm recovery speed of the beach concerned also play important roles we have quantified and compared beach erosion return levels resulting from single storms and storm clusters it was found that beach erosion volumes resulting from storm clusters with two or more storms resemble potential beach erosion volumes induced by single storms of far higher return periods

horizontal shortening control of middle miocene marine siliciclastic accumulation upper marine molasse in the southern termination of the savoy molasse basin northwestern alps southern jura

damage due to the mw 7 7 kutch india earthquake of 2001 abstract this paper presents a study of the damage due to the m w 7 6 7 7 intraplate kutch earthquake of 26 january 2001 it was a powerful earthquake with a high stress drop of about 20 mpa aftershocks up to m 4 have continued for 2 5 years the distribution of early aftershocks indicates a rupture plane of 20 25 km radius at depths of 10 45 km along an e w trending and south dipping hidden fault situated approximately 25 km north of the kutch mainland fault the moment tensor solution determined from regional broadband data indicates reverse motion along a south dipping by 47 fault the earthquake is the largest event in india in the last 50 years and the most destructive in the recorded history in terms of socioeconomic losses with 13 819 deaths including 14 in pakistan collapse severe damage of over a million houses and us 10 billion economic loss surface faulting was not observed however intense land deformations have been observed in a 40 20 km meizoseismal area these include lateral spreading ground uplifts about a meter ground slumping and deep cracks liquefaction with ejection of sand and copious water was widespread in the banni grassland rann areas salt plains along rivers and also in the coastal areas up to 200 km distance from the epicenter in areas of intensity vii to x stray incidences of liquefaction have occurred up to distances of at least 300 km for the first time in india multistory buildings have been destroyed damaged by an earthquake the maximum acceleration is inferred to be 700 cm s 2 and intensities are 1 3 units higher in soil covered areas than expected from the decay rate of acceleration for hard rock

brittle deformation in the inner nw alps from early orogen parallel extrusion to late orogen perpendicular collapse internal parts of the alps have undergone widespread extensional deformation in the course of their neogene exhumation history palaeostress inversion methods are used to map the prevailing stress fields and their evolution through time here we present new data from 100 sites with a total of about 2000 faults striae couples covering a large portion of the inner north western alps palaeostress tensors are mostly extensional although one third of them are transcurrent the dominant direction of minimum horizontal stress axes 3 is in an orogen parallel n30 to n70 orientation around the bend of the north west alpine arc a comparison between this older neogene post metamorphic stress field with the current stress and strain field determined from seismotectonics and geodesy indicates a change in deformation mode from early orogen parallel extrusion to a late and ongoing orogen perpendicular spreading

high resolution topography along surface rupture of the 16 october 1999 hector mine california earthquake mw 7 1 from airborne laser swath mapping in order to document surface rupture associated with the hector mine earthquake in particular the area of maximum slip and the deformed surface of lavic lake playa we acquired high resolution data using relatively new topographic mapping methods we performed a raster laser scan of the main surface breaks along the entire rupture zone as well as along an unruptured portion of the bullion fault the image of the ground surface produced by this method is highly detailed comparable to that obtained when geologists make particularly detailed site maps for geomorphic or paleoseismic studies in this case however for the first time after a surface rupturing earthquake the detailed mapping is along the entire fault zone rather than being confined to selected sites these data are geodetically referenced using the global positioning system thus enabling more accurate mapping of the rupture traces in addition digital photographs taken along the same flight lines can be overlaid onto the precise topographic data improving terrain visualization we demonstrate the potential of these techniques for measuring fault slip vectors

crustal velocity and strain rate fields in italy and surrounding regions new results from the analysis of permanent and non permanent gps networks summary we present a new geodetic velocity solution for italy and the surrounding areas obtained from an analysis of continuous and survey mode global positioning system observations collected between 1991 and 2002 we have combined local regional and global networks into a common reference frame velocity solution providing a new detailed picture of the regional scale deformation field in the central mediterranean our velocity estimates are computed with respect to a new stable eurasian reference frame constraining the kinematics of the greater african eurasian plate boundary system in the study area we provide strain rate values for the main seismotectonic districts which are in good agreement with the seismic deformation inferred from earthquake focal mechanisms the southern tyrrhenian area calabria the apennines the southeastern alps the southern dinarides and the albanides display deformation rates at the order of 20 30 nanostrain yr 1 the corsica sardinia block moves according to eurasian plate motions and there is no indication that the opening of the tyrrhenian is still active the pelagian and sicilian domains are separated by a northwest southeast discontinuity the sicily channel rifted area and marginally significant relative motion between the pelagian plateau and the african plate is also observed the southern tyrrhenian is affected by north south compression and accommodates up to 50 per cent of the africa eurasia relative plate motion whereas the calabrian arc exhibits 2 mm yr 1 northwest southeast extension the observed deformation pattern suggests the presence of a major approximately north south tectonic discontinuity separating the sicilian and calabrian domains an extensional boundary observed along peninsular italy coincides with the distribution of seismogenic faults along the axis of the apennines this boundary separates a tyrrhenian and an adriatic domain with diverging velocities orientated north nnw ward and northeastward respectively the apennines are extending perpendicularly to the chain axis at rates of less than 3 mm yr 1 and only in the outer northern apennines indications of active shortening are observed insignificant deformation is observed in the western po plain and the western alps while the central and eastern alps display north south shortening the eastern adriatic domain is shortening perpendicular to the dinaric front with strain rates increasing from north to south the locus of collision between the aegean balkan system and the adriatic and ionian domains is marked by the kephalonia fault system which accommodates up to 20 1 mm yr 1 of right lateral motion the deformation pattern observed in the peri adriatic domain is well described by a counter clockwise rotation of the adriatic microplate around a pole located in the western alps

architectural element analysis applied to glacial deposits internal geometry of a late pleistocene till sheet ontario canada deposits left by continental ice sheets are characterized by sedimentological complexity and stratigraphic heterogeneity but stratigraphic descriptions of such deposits and resulting first generation facies models are still based primarily on one or two dimensional borehole or outcrop data reconstruction of depositional environments hydrogeological investigations of pleistocene glacial deposits and hydrocarbon exploration in pre pleistocene glaciated basin fills require a more detailed understanding of the form and heterogeneity of lithofacies sequences in three dimensions architectural element analysis is used widely by sedimentologists for categorizing internal stratigraphic heterogeneity in sandstones particularly those of fluvial origin this paper demonstrates the first application of architectural element analysis to glacial deposits such as tills outcrop borehole and a broad range of subsurface geophysical data were collected from a thick 60 m till sheet present across an 80 km 2 study area near toronto canada the till sheet is not homogeneous but is composed of three distinct architectural elements and associated lithofacies viz diamict elements interbeds of subglaciofluvial sediments and glaciotectonically deformed zones application of architectural element analysis to these subglacial strata provides insights into the origin of drumlin bedforms and subglacial processes below the laurentide ice sheet and creates a framework for understanding ground water and contaminant movement in underlying aquifers

lithofacies palaeoecology and palaeoenvironments of the agrio formation lower cretaceous of the neuquen basin argentina abstract the lithofacies and macrofossil guilds of the agrio formation upper valanginian lower barremian have been analysed using evidence from sedimentological taphonomic and palaeoecological studies the study area is agua de la mula and adjacent regions in central neuquen seven lithofacies have been recognized in the field which indicate that the agrio formation was deposited in an open marine ramp depositional system under storm influence lithofacies indicate conditions that range from low energy basin to high energy inner ramp outer and mid ramp deposits are the most abundant macrofossils have been grouped into 16 guilds based on tiering life habit and feeding category the guilds indicate normal benthic oxygen level normal salinity and soft firm muddy and sandy bottoms suspension feeders are more common than deposit feeders suggesting the predominance of suspended food particles over deposited food resources a low input of siliciclastics and possibly other palaeoceanographic conditions allowed the development of oolitic facies in the inner ramp and coral patch reefs in the upper mid ramp for a limited period of time

an energy budget snowmelt model for the canadian prairies meltwater released by shallow snow covers of the canadian prairies is an important water resource to the region therefore many water management agencies are interested in methods of forecasting streamflow and seasonal water yield from snowmelt reliable accurate forecasts however require information of the time of melt and snowmelt rates and volumes at the present time these quantities are usually estimated by simple temperature index methods which have not proven successful in open grassland environments the paper describes the development and testing of a snowmelt model that uses the energy equation as its physical framework empirical procedures for evaluating radiative convective advective and internal energy terms from standard climatological measurements are presented algorithms for accounting for changes in the energy terms in a daily energy balance model are described the application of the energy budget snowmelt model ebsm for predicting ablation and simulating streamflow from small

modeling increases in snowmelt yield and desynchronization resulting from forest gap thinning treatments in a northern mountain headwater basin 1 a physically based model built upon extensive field observations of radiation dynamics and snow processes in cold regions forest environments was used to investigate the impacts of prescribed forest gap thinning treatments on spring snowmelt in a small saskatchewan river headwater basin of the canadian rocky mountains both field observations and model simulations showed that snow accumulations in small clear cut gaps was roughly double those under intact forest cover due to sublimation losses from the canopy consequently mountain forests thinned with small clear cut gaps resulted in a substantial increase in the magnitude of spring snowmelt however the impact of forest thinning on the timing of snowmelt was highly dependent on slope orientation thinning accelerated snowmelt on south facing slopes primarily through enhanced shortwave radiation but retarded snowmelt on north facing slopes primarily through reduced incoming longwave radiation as a result thinning treatments across opposing north facing and south facing mountain slopes acted to substantially expand the spring melt period in the basin and illustrated the important hydrological control imparted by intact forest cover through its synchronization of snowmelt across complex terrain a sensitivity analysis of snowmelt timing to varying spring meteorological conditions strongly suggests that shifts in spring snowmelt runoff from similar forest thinning treatments in mountain regions will depend on the slope and aspect at which they occur in combination with the seasonal timing of snowmelt resulting from latitude controlled solar elevation effects

large river offsets and plio quaternary dextral slip rate on the red river fault yunnan china using multispectral spot images and 1 100 000 topographic data we present an improved map of the active red river fault zone between midu yunnan china and hanoi vietnam the fault zone is composed of parallel strands one of which the yuanjiang fault was previously undetected there also appears to be a component of extension all along the fault zone such extension increases toward the se from yunnan to the south china sea coast and the vector describing the motion of south china relative to indochina points within the n45 135 e quadrant we attempt to assess the plio quaternary dextral slip rate on the red river fault rrf by restoring large river offsets and searching for the largest plausible one across much of yunnan the fault is perpendicular to local catchments that drain into the red river from precise mapping of the river courses on spot satellite images and on 1 100 000 topographic maps numerous multiple offsets along the fault can be detected and reconstructed the lack of correlation between the apparent offsets and the lengths of the rivers upstream from the fault suggests either that the drainage system was in large part established prior to the onset of dextral slip along the fault or that frequent captures have occurred we thus try to find the best fit between series of river channels upstream and downstream from the fault by progressively restoring the dextral displacement in increments of 500 m up to an offset of 50 km for each increment we measure the misfits root mean squares rms between the upstream and downstream channels the best fit and smallest rms are obtained for an offset of 25 0 5 km that we interpret to represent the clearest large right lateral displacement recorded in the geomorphology along the active red river fault since dextral motion is likely to have started around 5 myr the most probable average plio quaternary slip rate on the fault is of order of 5 mm yr we attribute the apparent lack of seismic activity on a large stretch of the fault to millennial recurrence times between great earthquakes our study shows that relatively small drainage systems can keep a good record of fairly large cumulative fault offsets

morphodynamics of a bar trough surf zone abstract a field study was made of the distinguishing morphodynamic processes operating in a surf zone which perennially exhibits accentuated bar trough topography the longshore bar trough and rhytmic bar and beach states as described by wright and short 1984 characteristic features of the morphology include a shallow bar with a steep shoreward face a deep trough and a steep beach face this morphology which is favored by moderate breaker heights and small tidal ranges strongly controls the coupled suite of hydrodynamic processes in contrast to fully dissipative surf zones the bar trough surf zone is not at all saturated and oscillations at incident wave frequency remain dominant from the break point to the subaerial beach the degree of incident wave groupiness does not change appreciably across the surf zone infragravity standing waves which in dissipative surf zones dominate the inshore energy remain energetically secondary and occur at higher frequencies in the bar trough surf zone analyses of the field data combined with numerical simulations of leaky mode and edge wave nodal antinodal positions over observed surf zone profiles indicate that the frequencies which prevail are favored by the resonant condition of antinodes over the bar and nodes in the trough standing waves which would have nodes over the bar are suppressed sediment resuspension in the surf zone appears to be largely attributable to the incident waves which are the main source of bed shear stress in addition the extra near bottom eddy viscosity provided by the reformed non breaking waves traversing the trough significantly affects the vertical velocity profile of the longshore current whereas the bar is highly mobile in terms of onshore offshore migration rates the beach face and inner regions of the trough are remarkably stable over time

spectral signatures for swash on reflective intermediate and dissipative beaches in this paper we synthesise a large data set gathered from a wide variety of field deployments and integrate it with previously published results to identify the spectral signatures of swash from contrasting beach types the field data set includes the full range of micro tidal beach types reflective intermediate and dissipative with beach gradients ranging from approximately 1 6 to 1 60 exposed to offshore significant wave heights of 0 5 3 0 m the ratio of swash energy in the short wave f 0 05 hz to long wave f 0 05 hz frequency bands is found to be significantly different between the three beach types swash energy at short wave frequencies is dominant on reflective and intermediate beaches and swash at long wave frequencies is dominant on dissipative beaches consistent with previously reported spectral signatures for the surf zone on these beach types the available swash spectra were classified using an automated algorithm clara into five different classes the ordered classes represent an evolution in the spectrum shape described by a frequency downshifting of the energy peak from the short wave into the long wave frequency band and an increase in the long wave swash energy level compared to a relatively minor variation in the short wave swash energy level a universally common feature of spectra from all beach states was an f 4energy roll off in the short wave frequency band in contrast to the broadly uniform appearance of the short wave frequency band the appearance of the long wave frequency band was highly variable across the beach states we incorporate the results presented here and previously published observations into the morphodynamic beach state model and propose an ordered sequence of swash spectra under increasing and decreasing incident wave energy level this extension of the beach state model to include the swash zone leads to the following propositions for morphodynamic controls on the nature of the swash spectrum 1 the short wave part of the swash spectrum is relatively constant in form across all beach states f 4 energy roll off and the energy density per unit frequency is controlled by the beach face gradient alone 2 the spectral bandwidth of the energy roll off varies directly with offshore wave energy level and inversely with beach face gradient or beach state in a manner consistent with the non linear wave breaking criterion 3 the infragravity part of the swash spectrum is highly variable in form across all beach states and the energy level is related to the offshore wave energy level and surf zone morphology

fault slip distribution of the 1999 mw 7 1 hector mine earthquake california estimated from postearthquake airborne lidar data the 16 october 1999 hector mine earthquake m w 7 1 was the first large earthquake for which postearthquake airborne light detection and ranging lidar data were collected to image the fault surface rupture in this work we present measurements of both vertical and horizontal slip along the entire surface rupture of this earthquake based on airborne lidar data acquired in april 2000 we examine the details of the along fault slip distribution of this earthquake based on 255 horizontal and 85 vertical displacements using a 0 5 m digital elevation model derived from the lidar imagery the slip measurements based on the lidar dataset are highest in the epicentral region and taper in both directions consistent with earlier findings by other works the maximum dextral displacement measured from lidar imagery is 6 60 1 10 m located about 700 m south of the highest field measurement 5 25 0 85 m our results also illustrate the difficulty in resolving displacements smaller than 1 m using lidar imagery alone we analyze slip variation to see if it is affected by rock type and whether variations are statistically significant this study demonstrates that a postearthquake airborne lidar survey can produce an along fault horizontal and vertical offset distribution plot of a quality comparable to a reconnaissance field survey although lidar data can provide a higher sampling density and enable rapid data analysis for documenting slip distributions we find that relative to field methods it has a limited ability to resolve slip that is distributed over several fault strands across a zone we recommend a combined approach that merges field observation with lidar analysis so that the best attributes of both quantitative topographic and geological insight are utilized in concert to make best estimates of offsets and their uncertainties

active tectonics of the adriatic region from gps and earthquake slip vectors 1 to investigate the kinematics of the adriatic region we integrate continuous and episodic gps measurements with mw 4 5 earthquake slip vectors selected from the regional centroid moment tensor catalogue coherent motion of gps sites in the po valley in apulia and in the hyblean plateau allows us to estimate geodetically constrained angular velocities for these regions the predictions of the gps inferred angular velocities are compared with the earthquake slip vectors showing that the seismically expressed deformation at the microplate boundaries is consistent with the observed geodetic motion the remarkable consistency between geodetic seismological and geological evidence of active tectonics suggests that active deformation in the central adriatic is controlled by the relative motion between the adria and apulia microplates the microplates angular rotation rates are then compared with the rotation rates calculated with a simple block model supporting the hypotheses 1 that apulia forms a single microplate with the ionian sea and possibly with the hyblean region and 2 that adria and apulia rotate in such a way as to accommodate the eurasia nubia relative motion we suggest that the present day microplate configuration follows a recent fragmentation of the adriatic promontory that during the neogene rigidly transferred the africa motion to the orogenic belts that now surround the adriatic region

anatomy and sedimentary model of a hooked spit sylt southern north sea a sedimentary model for hooked spit depositional systems based on ground penetrating radar and sedimentological data is presented the recurved main spit of sylt island southern north sea is dominated by migrating sand dunes the investigated hooked spit exhibits a system of foredune ridges oriented perpendicular to the dunes of the recurved spit the development of the hooked spit is related closely to the presence of an adjacent tidal inlet where strong tidal currents and a steep bathymetry prevent a further northward progradation of the main spit and trigger a deflection from northerly directed to easterly directed net sediment transport ground penetrating radar data and shallow sediment cores reveal the sedimentary architecture of the hooked spit in high resolution and allow the proposition of a genetic stratigraphic model it is shown that the growth of the hooked spit is controlled by the interplay of alongshore migrating foreshore beach drifts under fair weather conditions and strong erosional events interpreted as the result of rare severe storms these storms may excavate scarps in the backshore which play an important role in the development of foredune ridges accelerator mass spectrometry 14c ages indicate an absolute age of at least 1300 years for the hooked spit which possibly correlates with strengthened erosion of the main spit in contrast to the main spit where the sediment budget is negative nowadays growth of the hooked spit beach accelerated significantly during the last decades this effect can probably be attributed to enhanced beach nourishments updrift along the main spit and makes the investigated hooked spit a natural laboratory to study the influence of increasing sediment supply into a system developing under the conditions of sea level rise the study shows that the same external forces lead to distinct progradational processes along one barrier spit system

architectural elements and bounding surfaces in fluvial deposits anatomy of the kayenta formation lower jurassic southwest colorado abstract three well exposed outcrops in the kayenta formation lower jurassic near dove creek in southwestern colorado were studied using lateral profiles in order to test recent regarding architectural element analysis and the classification and interpretation of internal bounding surfaces examination of bounding surfaces within and between elements in the kayenta outcrops raises problems in applying the three fold classification of allen 1983 enlarging this classification to a six fold hierarchy permits the discrimination of surfaces intermediate between allen s second and third order types corresponding to the upper bounding surfaces of macroforms and internal erosional reactivation surfaces within the macroforms examples of the first five types of surface occur in the kayenta outcrops at dove creek the new classifications is offered as a general solution to the problem of description of complex three dimensional fluvial sandstone bodies the kayenta formation at dove creek consists of a multistorey sandstone body including the deposits of lateral and downstream accreted macroforms the storeys show no internal cyclicity neither within individual elements nor through the overall vertical thickness of the formation low paleocurrent variance indicates low sinuosity flow whereas macroform geometry and orientation suggest low to moderate sinuosity the many internal minor erosion surfaces draped with mud and followed by intraclast breccias imply frequent rapid stage fluctuation consistent with variable seasonal monsonal ephemmeral flow the results suggest a fluvial architecture similar to that of the south saskatchewan river through with a three dimensional geometry unlike that interpreted from surface studies of that river

current strain regime in the western alps from continuous global positioning system measurements 1996 2001 four to six years of continuous measurements at 10 permanent global positioning system sites in the western alps show horizontal residual velocities of 2 mm yr with respect to stable europe uncertainties range from 0 3 to 1 4 mm yr these velocities and the associated strain rate field indicate that the central part of the range is currently dominated by east west extension whereas the southern part shows north south to northwest southeast compression the geodetic and seismotectonic data are consistent with a model where strain is essentially controlled by the counterclockwise rotation of the adriatic microplate with respect to eurasia this rotation together with the arcuate shape of the contact between the adriatic microplate and the alps induces dextral shear kinematic boundary conditions across the western alps with an additional divergence component in their central part and in switzerland and a convergence component in their southern part

cross shore suspended sediment transport in the surf zone a field based parameterization existing cross shore sediment transport models for two dimensional surf zone bathymetries almost invariably predict offshore directed sand transports and bar migrations during storm conditions however onshore directed suspended sediment fluxes and associated nearshore bar migration were observed during recent field experiments on a gently sloping beach on the danish north sea coast field measurements of suspended sediment flux obtained during three experiments on two different beaches are used to parameterize the observed fluxes this parameterization predicts suspended sediment transport due to incident waves and undertow across bars in two dimensional surf zones first a non dimensional sediment flux index is formulated which describes the tendency towards net onshore or offshore transport and the strength of that tendency the non dimensional formulation circumvents the problem of measurement inconsistencies due to varying elevations of sediment concentration sensors relative to the bed the index is found to depend upon the undertow velocity the incident wave skewness and the cross correlation between orbital velocity and sediment concentration however some of these parameters are difficult to predict particularly in barred surf zones and therefore the independent variables are recast in terms of a set of more easily obtainable parameters the sediment flux index depends on a combination of the following non dimensional bed shear stress the shields parameter relative water depth wave orbital velocity relative wave height and bed slope finally a formulation of suspended sediment transport across bars is obtained by linking the flux index with a parameterization of the sediment concentration distribution in the water column these concentrations are found to depend on non dimensional bed shear stress relative wave height and water depth the formulation predicts a tendency for onshore directed sediment transport due to incident waves on gently sloping beaches and or with large bed shear stresses on steeply sloping beaches and or in the inner part of the surf zone there is a tendency towards offshore sediment transports due to the undertow

the earthquake potential of the new madrid seismic zone the fault system responsible for new madrid seismicity has generated temporally clustered very large earthquakes in a d 900 100 years and a d 1450 150 years as well as in 1811 1812 given the uncertainties in dating liquefaction features the time between the past three new madrid events may be as short as 200 years and as long as 800 years with an average of 500 years this advance in understanding the late holocene history of the new madrid seismic zone and thus the contemporary tectonic behavior of the associated fault system was made through studies of hundreds of earthquake induced liquefaction features at more than 250 sites across the new madrid region we have found evidence that prehistoric sand blows like those that formed during the 1811 1812 earthquakes are probably com pound structures resulting from multiple earthquakes closely clustered in time or earthquake sequences from the spatial distribution and size of sand blows and their sedimentary units we infer the source zones and estimate the magnitudes of earth quakes within each sequence and thereby characterize the detailed behavior of the fault system it appears that fault rupture was complex and that the central branch of the seismic zone produced very large earthquakes during the a d 900 and a d 1450 events as well as in 1811 1812 on the basis of a minimum recurrence rate of 200 years we are now entering the period during which the next 1811 1812 type event could occur

the 1356 basel earthquake an interdisciplinary revision summary within historical times one of the most damaging events in intra plate europe was the 1356 basel earthquake given its significance for assessing regional seismic hazard in central europe an interdisciplinary project was launched in 2005 to re explore this event our effort aimed to incorporate techniques from history seismology archaeology paleoseismology and engineering new and reinterpreted historical data from basel and its surroundings plus archaeological findings on buildings that survived the event and still exist enabled this macroseismic assessment palaeoseismological studies combined with historical evidence provided additional data for the surrounding areas archaeology offers sparse information on some castles and churches sometimes supported by historical records a contemporary source allows some reconstruction of the stronger fore and aftershocks this expanded information base improves our sense of the event s damage and consequences for the city of basel the relatively abundant archaeological data allowed us to assess statistically the macroseismic intensity at ix although the pattern of damage was scattered data points for the expected area of damage around basel are not distributed regularly the absence of historical and archaeological findings for southern germany might be due to archival problems future investigation may improve this situation our results confirm that the basel earthquake was the most destructive known for central europe intensities up to viii are found within a radius of about 30 km analysing the macroseismic field confirms our former assessment of the event and shows an epicenter located about 10 km south of basel the most probable range for the moment magnitude mw is between 6 7 and 7 1

source parameters of the 11 june 1909 lambesc provence southeastern france earthquake a reappraisal based on macroseismic seismological and geodetic observations 1 destructive earthquakes are rare in france yet pose a sizable seismic hazard especially when critical infrastructures are concerned only a few destructive events have occurred within the instrumental period the most important being the 11 june 1909 lambesc provence earthquake with a magnitude estimated at 6 2 rothe 1942 the event was recorded by 30 observatories and produced intensity ix effects in the epicentral area 30 km north of marseille we collected 30 seismograms leveling data and earthquake intensities to assess the magnitude and possibly the focal mechanism of this event following this multidisciplinary approach we propose a source model where all relevant parameters are constrained by at least two of the input data sets our reappraisal of the seismological data yielded mw 5 7 6 1 6 0 preferred and ms 6 0 consistent with the magnitude from intensity data me 5 8 and with constraints derived from modeling of coseismic elevation changes hence we found the lambesc earthquake to have been somewhat smaller than previously reported our data sets also constrain the geometry and kinematics of faulting suggesting that the earthquake was generated by reverse right lateral slip on a wnw striking steeply north dipping fault beneath the western part of the trevaresse fold this result suggests that the fold located in front of the luberon thrust plays a significant role in the region s recent tectonic evolution the sense of slip obtained for the 1909 rupture also agrees with the regional stress field obtained from earthquake focal mechanisms and microtectonic data as well as recent gps data

structural inheritance and cenozoic stress fields in the jura fold and thrust belt france abstract based on an analysis of 8000 minor fault slip data in the jura mountains france we discuss the influence of pre existing discontinuities on the development of fold and thrust belts we present palinspastic maps showing the stress fields and active faults during the cenozoic pre orogenic events in the jura belt prior to the main late miocene fold and thrust tectonics during the eocene a n s strike slip regime produced a few nne ssw sub vertical strike slip faults in the central external jura and a few e w reverse faults in the eastern jura near the future frontal thrust during the oligocene an average wnw ese extension with irregular stress trajectories resulted in normal faulting along n s to ne sw trends in the external part of the belt wnw ese trends along the future northern and northeastern frontal thrust and nw se trends in the internal jura the late miocene tectonics began with a strike slip regime with a fan shaped compressional trajectory it was followed by a stress field with similar stress direction but local 2 3 stress permutation resulted in strike slip regime domains contrasting with reverse regime domains stress deflections and permutations occurred near inherited cover and basement discontinuities major deformation zones like the jura frontal thrust onto the foreland the thrust of the internal central jura onto the external jura and the narrow deformation bands within the flat lying plateaus formed close to the inherited faults the structural style of the jura belt thus partly mimics the pre orogenic fault pattern stress deflections point to the pre orogenic faults express the indentation process of the jura by its hinterland and highlight successive slip events along major faults during the fold and thrust tectonics this case study illustrates the relevance of minor fault slip studies for characterizing both the pre orogenic tectonics and the kinematics of the deformation

internal architecture of a raised beach ridge system anholt denmark resolved by ground penetrating radar investigations abstract the internal architecture of raised beach ridge and associated swale deposits on anholt records an ancient sea level the holocene beach ridges form part of a progradational beach ridge plain which has been interpreted to have formed during an isostatic uplift and a relative fall in the sea level over the past 7700 years the ridges are covered by pebbles and cobbles and commonly show evidence of deflation material presumably removed from the beach ridges and adjacent swales form the present dune forms on anholt ground penetrating radar gpr reflection lines have been collected with 250 mhz shielded antennae across the fossil ridge and swale structures the signals penetrate the subsurface to a maximum depth of 10 m below the fossil features the gpr data resolve the internal architecture of the beach ridges and swales with a vertical resolution of about 0 1 m gpr mapping indicates that the holocene beach ridges are composed of seaward dipping beachface deposits as well as minor amounts of inland dipping deposits of wash over origin the beachface deposits downlap on underlying shoreface deposits and we use these surfaces as markers of a relative palaeo sea level the new data indicate that the highest relative sea level at about 8 5 m was reached 6500 years ago 700 years later the relative sea level had dropped 0 7 m indicating a change in the relative sea level around 1 mm year this fall in the relative sea level most likely records the influence of an isostatic rebound causing younger beach ridge deposits to indicate lower sea levels

the belledonne border fault identification of an active seismic strike slip fault in the western alps summary in the french western alps east of grenoble we identify the belledonne border fault as an active seismic fault this identification is based on the seismic monitoring of the grenoble area by the sismalp seismic network over the past 12 yr 1989 2000 we located a set of earthquakes with magnitudes ranging from 0 to 3 5 along a 50 km long alignment which runs in a n30 e direction on the western flank of the belledonne crystalline massif available focal solutions for these events are consistent with this direction n36 e strike slip fault with right lateral displacement these events along the belledonne border fault have a mean focal depth of 7 km in the crystalline basement with a probably very low slip rate the belledonne border fault has never been mapped at the surface where the otherwise heavily folded and faulted mesozoic cover makes this identification difficult historical seismicity also shows that over the past two and a half centuries a few events located mainly along the southern part of the belledonne border fault caused damage with the magnitude 4 9 1963 monteynard earthquake reaching intensity vii the most recent damaging event in the study area is the magnitude 3 5 1999 laffrey earthquake intensity v vi although its epicentre lies at the southern tip of the belledonne border fault there is clear evidence that aftershocks were activated by the left lateral slip of a n122 e striking fault the length of the belledonne border fault which could easily accommodate a magnitude 6 event as well as the proximity to the isere valley with its unlithified quaternary deposits up to 500 m thick known to generate marked site effects make the identification of the belledonne border fault an important step in the evaluation of seismic risk in the grenoble area besides the activity observed on the fault will now have to be taken into account in future geodynamic models of the western alps

recent state of stress change in the walker lane zone western basin and range province united states the nw to north trending walker lane zone wlz is located along the western boundary of the northern basin and range province with the sierra nevada this zone is distinguished from the surrounding basin and range province on the basis of irregular topography and evidence for both normal and strike slip holocene faulting inversion of slip vectors from active faults historic fault offsets and earthquake focal mechanisms indicate two distinct quaternary stress regimes within the wlz both of which are characterized by a consistent wnw 3 axis these are a normal faulting regime with a mean 3 axis of n85 9 w and a mean stress ratio r value r 2 1 3 1 of 0 63 0 74 and a younger strike slip faulting regime with a similar mean 3 axis n65 70 w and r values ranging between 0 1 and 0 2 this younger regime is compatible with historic fault offsets and earthquake focal mechanisms both the extensional and strike slip stress regimes reactivated inherited mesozoic and cenozoic structures and also produced new faults the present day strike slip stress regime has produced strike slip normal oblique slip and normal dip slip historic faulting previous workers have explained the complex interaction of active strike slip oblique and normal faulting in the wlz as a simple consequence of a single stress state with a consistent wnw 3 axis and transitional between strike slip and normal faulting maximum horizontal stress approximately equal to vertical stress or r 0 in both regimes with minor local fluctuations the slip data reported here support previous results from owens valley that suggest deformation within temporally distinct normal and strike slip faulting stress regimes with a roughly constant wnw trending 3 axis zoback 1989 a recent change from a normal faulting to a strike slip faulting stress regime is indicated by the crosscutting striae on faults in basalts 300 000 years old and is consistent with the dominantly strike slip earthquake focal mechanisms and the youngest striae observed on faults in plio quaternary deposits geologic control on the timing of the change is poor it is impossible to determine if there has been a single recent absolute change or if there is rather an alternating or cyclical variation in stress magnitudes our slip data in particular the cross cutting normal and strike slip striae on the same fault plane are inconsistent with postulated simple strain partitioning of deformation within a single regional stress field suggested for the wlz by wesnousky and jones 1994 the location of the wlz between the deep seated regional extension of the basin and range and the right lateral strike slip regional tectonics of the san andreas fault zone is probably responsible for the complex interaction of tectonic regimes in this transition zone in early to mid tertiary time the wlz appears to have had a similarly complex deformational history in this case as a back arc or intra arc region accommodating at least part of the right lateral component of oblique convergence as well as a component of extension