brittle tectonic reconstruction of palaeo extension inherited from mesozoic rifting in west zagros kermanshah iran abstract the present day zagros mountain belt of sw iran corresponds to the former arabian passive continental margin of the southern neo tethyan basin which existed since a permian triassic rifting episode and underwent later collisional deformation in mid to late cenozoic time in west zagros the kermanshah radiolarian trough separated from the neo tethyan basin by the narrow continental platform of the bisotun limestone resulted from the triassic jurassic rifting of the passive margin brittle tectonic analyses of syndepositional normal fault slip data have been undertaken to study the extensional history of the passive margin in terms of palaeostress reconstruction dominant east west trends of the inherited rift related normal faults in west zagros indicate an approximately north south trend of extension that prevailed during the entire mesozoic syn to post rift evolution of the radiolarian trough this extension characterizes a stretched continental margin similar to the present day passive margin of the british isles considering the structural pattern of the inherited basement faults as revealed by the present day earthquake focal mechanisms an oblique crustal stretching model is proposed for the rifting process

stress regime strain release and geothermal implicationsregional stress field and rifting in western europe in situ stress determination is one possibility to determine stress magnitudes in the earth s crust most measurements especially in the northern alpine foreland have been carried out by using the doorstopper technique stress magnitudes are presented as excess stresses a number of sites where stresses have been determined gave sufficiently high values to statistically determine stress directions for the following tectonic blocks 1 1 western alps 2 2 their immediate foreland with the rhinegraben and 3 3 the rhenish shield bordering on the rift segment of the lower rhine embayment in discussing results of the statistical analyses of stress data it is suggested that stresses measured in the western alps have mainly a topographic origin in the alpine foreland to the north of the rhenish shield topographic stresses are superimposed on active tectonic stress considering the structural and lithological differences the foreland blocks show a different response to the same tectonic stress field which trends for 1 at about 146 this active stress field causes shear rifting in the upper rhinegraben but extensional rifting in the lower rhine embayment in the rhenish shield area only local step faults are observed in direction of 1 due to the ductile behaviour of its basement

permian sedimentary record of the turpan hami basin and adjacent regions northwest china constraints on postamalgamation tectonic evolution the permian marks an important yet poorly understood tectonic transition in the tian shan region of northwestern china between devonian carboniferous continental amalgamation and recurrent mesozoic cenozoic intracontinental orogenic reactivation the turpan hami basin accommodated up to 3000 m of sediment and is ideally positioned to provide constraints on this transition new stratigraphic data and mapping indicate that extension dominated early permian tectonics in the region whereas flexural foreland subsidence controlled late permian basin evolution lower permian strata in the northwestern turpan hami basin consist of coarse grained debris flow and alluvial fan deposits interbedded with mafic to intermediate volcanic sills and flows in contrast lower permian rocks in the north central and northeastern turpan hami basin unconformably overlie a late carboniferous volcanic arc sequence these lower permian strata include possible shallow marine carbonate rocks and thick volcanic and volcaniclastic rocks that are in turn overlain by littoral to profundal lacustrine facies above a regional lower permian upper permian unconformity regional sedimentation patterns record the development of a more integrated sedimentary basin the upper permian is entirely nonmarine and can be correlated east west along the depositional strike of the basin the lower upper permian consists of a broad belt of braided fluvial deposits shed northward these strata are overlain by fluctuating littoral and profundal lacustrine facies and associated fluvial facies the uppermost permian is characterized by shallow lake plain and fluvial environments the early permian association of diffuse volcanism and partitioning of subbasins by normal faulting is consistent with an early phase of lithospheric extension local relationships indicate west east extension in the turpan hami basin along faults oriented normal to late devonian carboniferous collisional sutures within the tian shan the cause of extension in the wake of carboniferous orogenesis remains enigmatic however the temporal and spatial relationships of the two strain regimes suggest that they are genetically related upper permian stratigraphy and unconformities and local late permian triassic contractional deformation record foreland basin development when the turpan hami region became a wedge top basin with respect to the north tian shan fold and thrust belt flexurally induced late permian subsidence is also manifested in the larger junggar basin to the north where 4000 m of strata are preserved in the foredeep region the turpan hami and junggar basins were depositionally connected for much of the late permian when a vast lacustrine system developed across northwestern china this lacustrine paleogeography was only occasionally interrupted possibly by structural damming during uplift of the orogenic wedge

barotropic tides in the global oceans from a nonlinear tidal model assimilating altimetric tides 1 model description and results in this first part of a two part paper we present results from a high resolution data assimilative fully nonlinear barotropic tidal model of the global oceans that excludes the arctic the model assimilates in waters deeper than 1000 m altimetric tides derived from the analysis of 2 years of topex altimetric data it also assimilates tide gage data from coastal tide gages the model domain includes that covered by the altimeter and extends to the antarctic in the first part we present tidal results for the primary semidiurnal m2 s2 n2 and k2 and diurnal k1 o1 p1 and q1 constituents the second part deals with applications kantha et al this issue the model results are compared with observational data from pelagic gages these comparisons show that overall in the open ocean in deep waters away from the margins of the primary basins the model performance is comparable to other tidal models derived using topex data except for m2 and s2 however one advantage of this model compared with those based solely on the analysis of altimetric data is that the altimetry derived tides are subjected to dynamical constraints by the model this results in reduction of subtidal variability often folded into tidal signals by topex data analysis it is also shown that in shallow waters along the margins especially in east asian marginal seas the model differs substantially from these other models in addition to sea surface heights we also present dynamically consistent barotropic currents in the form of tidal ellipses for m2 and k1 constituents since the goal of this research is a global tidal model uniformly valid in both deep and shallow waters we finally present tidal elevations and currents on two well known shallow water areas the northwest european shelf and the northeast american shelf and a semienclosed western pacific marginal sea the bering sea the model results are compared with independent observations and where possible with results from other numerical models the results highlight the importance of bottom topography on the northwest european shelf where accurate bottom topography was included in the model the results are much better than on the northeast american shelf where the digital bathymetric data base 5 dbdb5 topographic database has significant errors results from the bering sea where the topography is more accurate than the dbdb5 compare well with known tides in the region

diurnal and semidiurnal variations in the earth s rotation rate induced by oceanic tides recent space geodetic observations have revealed daily and subdaily variations in the earth s rotation rate although spectral analysis suggests that the variations are primarily of tidal origin comparisons to previous theoretical predictions based on various ocean models have been less than satisfactory this disagreement is partly caused by deficiencies in physical modeling rotation predictions based on a reliable tidal height model with corresponding tidal currents inferred from a modified form of laplace s momentum equations yield predictions of tidal variations in universal time that agree with very long baseline interferometer observations to 2 microseconds this agreement resolves a major discrepancy between theory and observation and establishes the dominant role of oceanic tides for inducing variation in the earth s rotation at these frequencies

rhinegraben horizontal stylolites indicating stress regimes of earlier stages of rifting abstract buchner f 1981 rhinegraben horizontal stylolites indicating stress regimes of earlier stages of rifting in j h illies editor mechanism of graben formation tectonophysics 73 113 118 tectonic stylolites horizontal columns and their statistical distribution in middle triassic and jurassic limestones on both flanks of the rhinegraben are described and their relation to the rhinegraben taphrogenesis is discussed a generation of pre middle miocene nne striking horizontal stylolites and a subsequent generation of post lower miocene nw striking horizontal stylolites have been recognized the first generation stylolites indicates a horizontal compression in the nne ssw direction while the second generation indicates a compression in the nw se direction average maxima of joints parallel to the two horizontal stylolite maxima were found joints and their corresponding horizontal stylolites were formed under the same stress regime

the neotectonics of the tibetan plateau part of the continuing northward convergence between india and eurasia is probably taken up by strike slip displacement with tibet as a whole moving eastward away from the collision zone and undergoing east west extension molnar and tapponnier 1975 ni and york 1978 on the basis of our interpretation of landsat images we propose that strike slip faulting occurs throughout the tibetan plateau such that its north south cross section is being shortened with little contemporary folding or thrusting

accuracy assessment of recent ocean tide models over 20 global ocean tide models have been developed since 1994 primarily as a consequence of analysis of the precise altimetric measurements from topex poseidon and as a result of parallel developments in numerical tidal modeling and data assimilation this paper provides an accuracy assessment of 10 such tide models and discusses their benefits in many fields including geodesy oceanography and geophysics a variety of tests indicate that all these tide models agree within 2 3 cm in the deep ocean and they represent a significant improvement over the classical schwiderski 1980 model by approximately 5 cm rms as a result two tide models were selected for the reprocessing of topex poseidon geophysical data records in late 1995 current ocean tide models allow an improved observation of deep ocean surface dynamic topography using satellite altimetry other significant contributions include theft applications in an improved orbit computation for topex poseidon and other geodetic satellites to yield accurate predictions of earth rotation excitations and improved estimates of ocean loading corrections for geodetic observatories and to allow better separation of astronomical tides from phenomena with meteorological and geophysical origins the largest differences between these tide models occur in shallow waters indicating that the current models are still problematic in these areas future improvement of global tide models is anticipated with additional high quality altimeter data and with advances in numerical techniques to assimilate data into high resolution hydrodynamic models

numerical simulation of tides and oceanic angular momentum of titan s hydrocarbon seas abstract tides and tidal currents in titan s hydrocarbon seas are numerically simulated by a 3 dimensional ocean circulation model using a bathymetry map constrained by cassini these predictions are used to calculate the tidally induced variations of the oceanic angular momentum of the seas the tides behave as a quasi standing wave with anti nodes at the northern and southern shores the tidal currents in kraken mare are mainly oriented along the major axis of the sea and are dominated by fast hydraulic currents through a narrow strait the axial oceanic angular momentum primarily changes due to redistribution of liquids in kraken mare and maximizes when there is ebb at the northern shore and flood at the southern shore on the other hand variations of the equatorial oceanic angular momentum are contributed by both tides and tidal currents the oceanic torque between sea and sea bottom is minor compared to its atmospheric counterpart i e the mountain torque between atmosphere and mountains

plate tectonics and the evolution of the british isles this paper is an essay on the rationalism and difficulties of the geological corollaries of plate tectonics with illustrations particularly from the geological history of the british isles there is special emphasis on the mechanics of continental lithosphere in extension when basins are formed and in convergence whereby continental lithosphere thinned in extension is shortened and restacked to form orogenic belts an upper lithosphere stress concentrating elastic lid suffers extremely complex inhomogeneous deformations above a simpler viscoelastic lower lithosphere whose deformation drives strain and displacement in the elastic lid the very nature of plate tectonics as relative motion among a multi plate mosaic of plates provides a rational semi quantitative framework for large scale geological complexity in space and time the caledonian and hercynian history of the british isles may be explained semi quantitatively in terms of plate boundary evolution but it is not possible to define unequivocal solutions the rationalism of plate tectonics is exhibited on a smaller more direct field scale by many of the complexities of ophiolite complexes such as ballantrae scotland that can be explained as the effects of the evolution of ridge ridge transforms and by diachronous deformation and sedimentation in subduction accretion prisms such as the southern uplands deformational and sedimentary patterns in nw europe from triassic times to the present day resulted from a complex interaction of extensional events related to diachronous atlantic opening and compressional events related to sequential alpine shortening phases those widespread events are typical of intracontinental plate boundary systems and create great difficulties for the geologist wishing to decipher relative plate motion from geological sequences because huge areas much larger than the british isles must be analysed and synthesized before much sense can be extracted further difficulties arise from the palinspastic and preservation problems of convergent boundaries orogenic shortening telescopes and partially subducts facies belts most orogenic belts were assembled as a collage of displaced and rotated terrain elements that were subsequently flattened elongated and straightened to an apparent but deceiving simplicity therefore while plate tectonics provides a rational geological framework against which for example british basin evolution can be tested and explained we cannot yet use the geological effects of plate boundary evolution to reconstruct relative plate motion quantitatively

styles of positive inversion tectonics in the central apennines and in the adriatic foreland implications for the evolution of the apennine chain italy abstract integration of new field structural and geophysical data with existing information from the apennines chain in italy and its adjacent adriatic foreland indicates that the styles of positive inversion tectonics and the modes of interaction between the extensional and the subsequent compressive structures vary starting from the cretaceous the contractional deformation induced by the mainly north directed convergence of africa adria with respect to the european plate promoted the closure of various arms of the atlantic and the neo tethys oceans which opened in different times and with distinct orientations the mosaic of continental blocks carbonate platforms rift basins and oceanic domains with several geometries and orientations with respect to the axis of the subsequent compression and the resulting heterogeneities within the shallow sedimentary cover and the overall lithosphere strongly influenced both the structural evolution of the apennine orogenic belt and the intra continental deformation within the adriatic foreland field observations reveal that the steeply e and w dipping mesozoic cenozoic normal faults are systematically decapitated by sub horizontal or gently west dipping thrusts propagating with short cut trajectories pre thrusting normal faults were commonly deformed by later thrusts but little evidence seems to support their entire reactivation as high angle reverse faults this suggests that these shallow and steeply dipping discontinuities were not suitable to be reutilized by the superficial thin skinned thrust faults propagating within the sedimentary cover in contrast presumably late paleozoic and mesozoic w dipping normal faults appear moderately reactivated in the adriatic foreland and strong positive inversion tectonics affect the deeper and buried structural levels of the apennine chain within the latter the syn rift sediments in the hangingwall blocks of the fault bounded basins were totally extruded and generated the strong uplift of the thinned adria continental crust finally the contrasting styles of interactions of the pre existing normal faults with later thrusts i e passive truncation or positive reactivation strictly result from the different evolution of the apennine chain and the combined thin and thick skinned modes of deformation of the stretched lithosphere of the adria plate

continental extension of the pacific plate at the southern termination of the hikurangi subduction zone the north mernoo fault zone offshore new zealand a complex transition from subduction at the hikurangi margin to transpressive continental collision across the southern alps occurs in the ne south island region of new zealand offshore the southern limit of oceanic subduction is constrained by the chatham rise a submerged continental plateau on the pacific plate which is presumably too buoyant for normal subduction in the nw corner of the rise is the north mernoo fault zone nmfz a 100 by 300 km region of basement involved active normal faulting of late miocene circa 8 6 ma to recent age the nmfz evolved contemporaneously with the rotation and development of the adjacent plate boundary zone growth faulting is characteristic within the sedimentary cover which is generally less than 2 km thick but the distribution of faulting has varied temporally the amount of mid pliocene recent extension is estimated to be not more than a few percent the nmfz consists of an array of overlapping south dipping normal faults which are typically 2 5 km apart and which trend roughly e w at a high angle to the plate boundary zone late quaternary surface traces are widely distributed on the mid to upper continental slope but many surface scarps are poorly preserved due to extensive erosion of the seafloor the western end of the fault zone crosses submarine canyons at the southern end of the hikurangi trough and almost abuts two fold and thrust fault systems on the ne south island continental margin although few data constrain the kinematics of extension a single mw 6 1 earth quake at the western end of the nmfz suggests planar rotating faults with a component of left lateral oblique slip two possible models of regional extension are considered 1 lateral buckling of the upper crust in which faulted slivers of crust are peeled off as the chatham rise slides past the transpressive marlborough fault system toward the southern alps and 2 flexure of the edge of continental pacific plate as the chatham rise is bent downward into the southern end of the hikurangi subduction zone improved seismological data and deep crustal seismic reflection profiles may help to constrain the kinematics of deformation

topographic lineament swarms clues to their origin from domain analysis of italy regional scale subparallel linear topographic features characterize almost all planetary surfaces this experiment concerns their tectonic meaning by focusing on map limits or domains through which individual swarms of these linear features are developed these domain limits are contrasted with map boundaries of better known structural features in a tectonically active region italy to seek clues to stress environments and times of origin of the lineaments the study uses regional raised relief maps to filter the lineament data to a very simple subset those strictly topographic features of a length and prominence capable of retaining detectability through generalizations required by relief map production a total of 5 372 lineaments were drawn using 4 differently lighted images of 1 1 000 000 scale relief maps of italy seven different tests were used for reliability and reproducibility of the data rose diagrams were prepared for 86 subareas by computer fitting of gaussians to azimuth frequency histograms individual azimuthal petals of these roses were then correlated to delimit the general area over which a given azimuthal swarm is developed the precise swarm boundaries were then located by computer contouring the population density of lines of each swarm on the original data set in this way 48 local swarms were mapped boundaries of these swarms correlate poorly with traditional litho tectonic provinces instead they seem to be associated with basin axes broad arches coastal flexures areas of normal fault swarms and projections of structural grain from adjacent sea floors the 48 domains may be grouped into 8 noncontiguous but azimuthally compatible super swarms covering much of italy the most prominent of the super swarms are greatly expanded versions of regional structural grains trend of the po basin axis of the upper adriatic basin zone of south alpine underthrusting and landward extensions of structural grain of the tyrrhenian sea from these relationships a model for lineament swarm origins is proposed involving very minor regional stretching of the thin brittle carapace of extremely large sometimes subtle structures deforming by ductile mechanisms at depth

a late cenozoic regional mesofracture system in southern england and northern france the upper cretaceous and palaeogene rocks of s england and n france are cut by a nw trending system of fractures characterized by swarms of vertical extension joints accompanied by conjugate sets of hybrid and shear joints and normal mesofaults many major photolineaments exhibit the same nw trend as the fractures and are particularly conspicuous in n france where they are coincident with rectilinear drainage channels suggesting a relationship between fracture orientation and physiography in s england this relationship is absent possibly because of the influence of additional fracture systems related to major flexures trending obliquely to the nw se direction these major e w trending flexures and associated fracture systems were formed during the oligocene to early miocene 9helvetic9 phase of deformation and are cross cut obliquely by fractures in the nw trending system the nw trending fractures and lineaments are parallel to neotectonic normal faults in the lower rhine embayment and become less well developed to the west with increasing distance from these major structures the lower rhine faults were reactivated and propagated into the quaternary cover as a consequence of ne sw regional tension generated during the late neogene to recent 9jura9 phase of nw se alpine convergence the nw trending extensional structures in s england and n france are considered to be of about the same age and related to the same stress regime as the neotectonic normal faults of the lower rhine embayment however because fractures of the nw system cutting palaeogene sediments in se england are truncated by the erosion surface beneath the plio pleistocene red crag deposits it is possible that in england fracture initiation did not continue into quaternary times

stress state reconstruction of oblique collision and evolution of deformation partitioning in w zagros iran kermanshah summary the w zagros of iran is characterized by a deformation partitioning pattern with a right lateral strike slip motion along the main recent fault and a shortening component across the zagros simple fold belt under the late cenozoic n s oblique collision between the arabian and iranian continental plates in this study we examined the brittle structures that developed during the mountain building process in the high zagros belt of kermanshah province which is structurally located between the two partitioned components of deformation to decipher the history of polyphase deformation and variations in stress fields within the sedimentary cover since the onset of collision the earthquake focal mechanisms of w zagros were analysed to evaluate the recent stress fields within the basement analytic inversion techniques enabled us to determine and separate different brittle tectonic regimes in terms of stress tensors brittle tectonic analyses were carried out to reconstruct possible geometrical relationships between different structures and to establish relative chronologies of the corresponding stress tensor with reference to folding our stress reconstruction indicates a major change in stress state from a miocene pliocene syn folding compressional regime to a pliocene recent post folding strike slip system with a significant anticlockwise reorientation of the horizontal 1 stress axis from ne sw to n s the results of the recent stress states indicate that the stress trends are similar throughout the basement and sedimentary cover the differences between stress and strain axes suggest different possible degrees in partitioning of seismic and aseismic deformation as revealed by earthquake focal mechanisms in the basement and geodetic surveys at the surface of the sedimentary cover the integrated palaeostress results on the regional tectonic framework suggest that the late cenozoic brittle tectonic evolution of the w zagros was achieved through the transition from thin to thick skinned deformation under the oblique plate convergence highlighting a southwestward shift of the deformation partitioning during the final pliocene collisional reorganization

field evidence for active normal faulting in tibet crustal thickening does not now occur in southern tibet field observations made during the chinese french expedition of 1980 support an earlier hypothesis based on a combined analysis of satellite images and fault plane solutions of earthquakes immediately north of the highest peaks of the himalayas the tectonic regime is dominated by east west extension we have mapped a large number of north south normal faults which sharply cut the glacial and post glacial morphology and followed several recent earthquake breaks along faults detected on satellite and aerial photographs microtectonic measurements in the quaternary suggest that the maximum principal stress is vertical

late cretaceous and early miocene andean type plutonic activity in northern makran and central iran two calc alkaline plutonic complexes bazman and natanz intruded through the south eastern active and south western ancient continental margins of central iran have been dated by the rb sr whole rock isochron method at 74 2 and 24 4 5 ma respectively detailed trace element studies together with low 87 sr 86 sr initial ratios 87 sr 86 sr ratios and the gabbros at least were intruded some 10 ma earlier

contrasting tectonic and sedimentary history of the central and eastern parts of the polish carpathian foredeep basin results of seismic data interpretation polish carpathian foredeep basin pcfb is located at the junction between western and eastern european platforms such location caused different evolution of various parts of this basin in the central part of the pcfb growth fault propagation folds related to latest badenian stages of thrusting in this segment of the carpathians developed only minor normal faulting related to miocene reactivation of older basement faults was detected paleovalleys mapped within the mesozoic basement were interpreted as palaeogene tectonically controlled erosional features developed after inversion of the polish trough in the central pcfb post evaporitic sediments were supplied into the foredeep basin from south from the eroded carpathians in the eastern part of the pcfb a system of large normal faults related to miocene flexure induced reactivation of inherited mesozoic faults was identified within the hangingwall of this system reverse faults rotated blocks and basement pop up structures were described their formation was related to combined effect of compressional stresses transferred from the carpathian collision zone and reactivation of older large scale fault caused by both flexural extension and strike slip movements during deposition of the miocene foredeep sediments differential compaction also played an important role gentle onlap of the middle badenian evaporites by post evaporitic sediments towards the nw was interpreted as a result of tectonically driven relative sea level rise and re establishment of marine connections with eastern paratethys

evolving alluvial stratigraphy and thrust front development in the west jaca piggyback basin spanish pyrenees in the southwestern pyrenees distinctive alluvial mega sequences correlate with the development of a shallow mountain front thrust structure the pena flexure the flexure evolved during the oligocene to early miocene and is interpreted as a duplex marking the limit of thrust front advance three main depositional facies preserved completely across the pena flexure are described a pre thrust emergence high sinuosity fluvial sequence the c 2300 m thick sheet sandstone facies of the campodarbe formation a syn thrust emergence conglomeratic alluvial fan sequence the c 1100 m thick conglomeratic facies of the bernues formation and a post thrust emergence low sinuosity fluvial sequence the 700 m thick ribbon sandstone facies of the uncastillo formation collectively their continuous exposure across the pena flexure provides a more or less complete record of the sedimentary evolution of a mountain front syn deformational features in the alluvial fan sequence of the bernues formation and marked contrasts in palaeochannel morphology sandstone body geometry and palaeocurrent patterns between the two fluvial sequences are best understood by invoking a strong tectonic control over their deposition an increased rate of vertical sediment accretion was a key process in determining fluvial style the onset of major thrusting led to more rapid basin floor subsidence thereby promoting a change from lateral to vertical accretion as channels responded to the rising base level

successive episodes of normal faulting and fracturing resulting from progressive extension during the uplift of the holy cross mountains poland conjugate normal faults extension fractures and mesh fracture structures were investigated in devonian carbonate rocks from the southern part of the holy cross mountains hcm central poland strata folded during variscan deformations were later subject to uplift resulting in increasing extension in the upper part of the rock mass at a relatively shallow depth faults and fractures developed in an orderly vertical succession first mesh fracture structures and conjugate normal fault sets enclosing acute dihedral angles 2 of over 45 were formed next conjugate normal faults with 2 less than 45 and sub vertical extension fractures developed the occurrences of conjugate normal sets enclosing different dihedral acute angles and extension fractures with similar strikes juxtaposed with each other at the same stratigraphic level point to the fact that the uplifted rock mass underwent successive changes in a stress regime leading to the formation of these structures the first sets of conjugate normal faults and fractures developed when the hcm were uplifted during a late stage of variscan deformations the next sets of extension fractures and conjugate normal faults developed during the following uplift events interrupted by periods of sedimentation of the mesozoic and younger strata

the effect of ocean tides on the earth s rotation as predicted by the results of an ocean tide model the published ocean tidal angular momentum results of seiler 1991 are used to predict the effects of the most important semidiurnal m2 s2 n2 diurnal k1 o1 p1 and long period mf mf mm and ssa ocean tides on the earth s rotation the separate as well as combined effects of ocean tidal currents and sea level height changes on the length of day ut1 and polar motion are computed the predicted polar motion results reported here account for the presence of the free core nutation and are given in terms of the motion within the rotating body fixed terrestrial reference frame of the celestial ephemeris pole so that they can be compared directly to the results of observations outside the retrograde diurnal tidal band the summed effect of the semidiurnal and diurnal ocean tides studied here predict peak to peak polar motion amplitudes as large as 2 mas within the retrograde diurnal tidal band the resonant enhancement caused by the free core nutation leads to predicted polar motion or equivalently nutation amplitudes as large as 9 mas at the unobservable retrograde k1 tidal frequency

impact of horizontal resolution and the advantages of the nested domains approach in the prediction of tropical cyclone intensification and movement received 14 december 2008 revised 16 february 2009 accepted 17 march 2009 published 4 june 2009 1 the prediction of the intensification and movement of the orissa super cyclone osc 1999 was studied using the national center for atmospheric research mm5 mesoscale atmospheric model a case study of the osc has been chosen as it is noted to be the most intense cyclone over the bay of bengal of this century experiments were made with a single domain 1d with two way interactive nested two domains 2d and with three domains 3d the model was integrated for 5 days and the model predicted intensity and track positions were compared with observations results indicate that the enhancement of resolution produces higher intensity and does not influence the track of the storm the nested 2d and 3d experiments produce cyclone track closely agreeing with the observations while the 1d experiments show the deviation of the track toward north and northeast after 48 h thus with increasing errors differences in the simulations with single and nested domains indicate that simulated atmospheric circulation on the eastern parts of the domain contribute to the deviation of the track in the 1d experimentandthesuccessfulsimulationwith2dand3dexperimentsisduetothetwo way interactive approach of the nested domains

the national meteorological center s quasi lagrangian model for hurricane prediction abstract a description is presented of the national meteorological center s quasi lagrangian model qlm which is used for operational hurricane prediction the model uses the primitive equations with high horizontal and vertical resolution and includes parameterizations of principal physical and dynamical processes that affect the motion and development of a hurricane because a storm s circulation is not well analyzed operationally due to a lack of observations a procedure was developed to insert an idealized vortex into the initial analysis the geopotential height and wind fields in the vortex satisfy the gradient wind relation with variable coriolis parameter and its structure depends on the size and intensity of the observed storm the primary purpose of the qlm is to provide numerical guidance for forecasting hurricane track considerable improvement in the track and the structure of a storm is obtained through the use of the idealized vortex further improvement in forecasts is attained with

clastic dike swarms and the structural evolution of the foreland fold and thrust belt of the southern andes clastic dike swarms are intruded into a cenozoic foreland fold and thrust belt in southern chile the dike material consists of sandstone and conglomerate with clasts as much as 25 cm in diameter brecciated wall rocks are also found in the clastic matrix the dikes often exceed 50 cm in width and hundred of metres in length in outcrop and are oriented overwhelmingly transverse to fold axes and parallel to cross joints the dike swarms are concentrated near the toe of major thrusts where they are found injected into the hanging wall a regional axial planar spaced cleavage is developed in the clastic dikes and sills clearly postdating injection of clastic material dike injection postdates at least the initiation of extension fractures the cross joint set within the swarms the dike intrusions represent as much as 20 extension parallel to fold axes in addition to several percent extension represented regionally by the cross joints the structural features of the dike swarms and their geometric relationship to other structures suggest rapid single phase injection the arrival of the front edge of a thrust on an already highly overpressured sedimentary sequence would cause an instantaneous increase in the overburden pressure and therefore could result in injection of a dense slurry of wet coarse sediments along preexisting planes of weakness field relationships of mesoscopic structures suggest the following evolution cross joint development incipient cleavage development initiation of thrusting and buckling clastic dike injection regional spaced cleavage development and associated late stage tightening of folds

active tectonics of the alpine himalayan belt between western turkey and pakistan summary over 80 new fault plane solutions combined with satellite imagery as well as both modern and historical observations of earthquake faulting are used to investigate the active tectonics of the middle east between western turkey and pakistan the deformation of the western part of this region is dominated by the movement of continental material laterally away from the lake van region in eastern turkey this movement helps to avoid crustal thickening in the van region and allows some of the shortening between arabia and eurasia to be taken up by the thrusting of continental material over oceanic type basement in the southern caspian mediterranean makran and black sea thus central turkey bounded by the north and east anatolian strike slip faults is moving west from the van region and overrides the eastern mediterranean at two intermediate depth seismic zones one extending between antalya bay and southern cyprus and the other further west in the hellenic trench the motion of northern iran eastwards from the van region is achieved mainly by a conjugate system of strike slip faults and leads to the low angle thrusting of iran over the southern caspian sea the seismicity of the caucasus shows predominantly shortening perpendicular to the regional strike but there is also some minor elongation along the strike of the belt as the causcasus overrides the caspian and black seas the deformation of the eastern part of this region is dominated by the shortening of iran against the stable borders of turkmenistan and afghanistan the north east direction of compression seen in zagros is also seen in north east iran and the kopet dag where the shortening is taken up by a combination of strike slip and thrust faulting large structural as well as palaeomagnetic rotations are likely to have occurred in ne iran as a result of this style of deformation north south strike slip faults in southern iran allow some movement of material away from the collision zone in ne iran towards the makran subduction zone where genuinely intermediate depth seismicity is seen within this broad deforming belt large areas such as central turkey nw iran azerbaijan central iran and the southern caspian appear to be almost aseismic and therefore to behave as relatively rigid blocks surrounded by active belts 200 300 km wide the motion of these blocks can usefully be described by poles of rotation the poles presented in this paper predict motions consistent with those observed and also predict the opening of the gulf of iskenderun ne of cyprus the change within the zagros mountains from strike slip faulting in the nw to intense thrusting in the se and the relatively feeble seismicity in se iran baluchistan this description also explains why the north south structures along the iran afghanistan border do not cut the east west ranges of the makran within the active belts surrounding the relatively aseismic blocks a continuum approach is needed for a description of the deformation even though motions at the surface may be concentrated on faults the evolution of fault systems within the active zones is controlled by geometric constraints such as the requirement that simultaneously active faults do not in general intersect many of the active processes discussed in this paper particularly large scale rotations and lateral movement along the regional strike are likely to have caused substantial complexities in older mountain belts and should be accounted for in any reconstructions of them

analogue simulation of natural orthogonal joint set formation in brittle varnish abstract two orthogonal joint sets are commonly observed in exposed sedimentary rocks with a wide variety of abutting and cross cutting relationships brittle varnish analogue models are carried out in conjunction with field studies in order to classify the different orthogonal fracture patterns and constrain the mechanical basis of orthogonal joint development the results suggest that the stress which creates the second joint set can result from i relaxation effects ii slight tension due to warping of the bands defined by the first parallel fractures and iii local and or regional reversals between 2 and 3 a ladder pattern formed by the combination of an initial set of long parallel joints and associated non cross cutting joints of the second set is obtained if the shear strength of the initial joints is low during the development of the second set a grid pattern where both sets mutually cross cut occurs when the shear strength of the initial joint set is high possibly the result of a high normal stress or healing and could result from two independent stress events an intermediate pattern comprising cross cutting and abutting orthogonal cross joints can form if the shear strength of the initial joints was intermediate and or variable during the development of the second set mutually abutting joint sets are observed within each pattern and could result from stress reversals or low differential stress during the final stages of joint development the classical presentation of joint data using rose diagrams cannot distinguish between the wide variety of orthogonal joint patterns maps of fracture intersections should compliment the orientation data we discuss methods to estimate the joint pattern where intersection data are absent

the tibetan side of the india eurasia collision results are reported from the 1980 joint french chinese field expedition in tibet the area covered was from the high himalaya in the south to the region of nagqu 250 km north of yangbajain ophiolites in the zangbo valley represent remnants of the crust of an ocean basin which lay adjacent to the gangdise granodiorite belt in the late mesozoic the ophiolites were thrust to the south onto the cretaceous melange and triassic flysch but the age of this event is unclear in the tertiary sediments of the indian margin and the xigaze basin were folded with steeply dipping cleavage which indicates some north south shortening of the crust however the tertiary volcanic sequence on the lhasa block and further north shows comparatively little folding and thrusting in the quaternary deformation of tibet was characterized by east west extension

regional joint sets in the arabian platform as indicators of intraplate processes the eastern part of the saudi arabian craton is a platform underlain by gently tilted and horizontal mesozoic cenozoic sedimentary rocks everywhere more than 250 km distant from the zagros deformation front despite its tectonic simplicity the platform contains several laterally extensive but subdued structures and lineaments belonging to more than one system of fault zones and flexures new microtectonic observations of dominant sets of extension and conjugate hybrid joints permit regionally significant extension directions to be inferred and the origin of the macrostructures to be assessed the central arabian arch the e w crest of which coincides with an axis of mesozoic subsidence developed during the late cretaceous to eocene when the basin inverted as a consequence of the emplacement of ophiolite bearing nappes on the zagros and oman margins during arching there was strike parallel elongation of beds at the same time as the arch amplified the central arabian graben system evolved as a result of the northward displacement of an east arabian block or sheet that became detached across an arcuate separation zone which in the south is coincident with the crest of the arch an important neogene response in the arabian platform to ne sw shortening in the zagros ranges was the formation of a swarm of ne striking master joints and lineaments these structures reflect the diffuse and peripheral expansion of the foreland beyond the zagros deformation front

sub daily resolution of earth rotation variations wtth global positioning system measurements data from a worldwide global positioning system gps tracking experiment have been used to determine variations in earth rotation ut1 utc over a time period of three weeks kalman filtering and smoothing enabled changes in ut1 utc over intervals of 2 to 24 hrs to be detected with the gps data internal consistency checks and comparisons with other solutions from very long baseline interferometry vlbi and satellite laser ranging slr indicate that the gps ut1 utc estimates are accurate to about 2 cm comparison of gps estimated variations in ut1 utc with 2 hr time resolution over 4 days with predicted variations computed from diurnal and semi diurnal oceanic tidal contributions strongly suggests that the observed periodic sub daily variations 0 1 msec 5 cm are largely of tidal origin

intracontinental wedging and post orogenic collapse in the mesohellenic trough the mesohellenic trough is a 130 km long and about 30 km wide subsiding area which contains a thick sequence of well exposed late cenozoic post orogenic sediments this intermontane basin located at the contact between the apulian and pelagonian collided margins provides a good example of the characteristics needed to study the chronology of late orogenic intracontinental structures

the foreland deformation in the south western basque cantabrian belt spain abstract in the south western portion of the cenozoic basque cantabrian belt structural data collected in pre orogenic upper cretaceous limestones were combined with aerial images interpretation in flat lying areas observations about fracture strike type orientation and overprinting relationships both at the macro and mesoscales allow to constrain the pre thrusting and pre folding deformational sequence that affected the area when it was forming part of the foreland basin wnw ese striking extensional structures represent the oldest elements developed during the very late stages of the mesozoic rifting associated with the opening of the bay of biscay the onset of convergence is marked by the development of extensional structures striking roughly nnw sse and wsw ene which are associated with belt parallel stretching in the foredeep and outer arc extension in the peripheral bulge respectively and developed in a non fluid assisted environment these elements are postdated by a pre folding layer parallel shortening pattern which includes wsw ene striking pressure solution cleavages and reverse faults both of them frequently reactivating inherited early orogenic wsw ene striking extensional elements and right lateral reactivation of wnw ese striking pre orogenic extensional structures this stage was followed by a syn to post folding e w oriented belt parallel compression wnw ese striking left lateral faults being the most outstanding elements associated with this stage the presence of such elements in upper cretaceous sediments provides support to the idea that left lateral shear zones of the area related with a cenozoic intrabelt lateral extrusion tectonics our results indicate coherently with previously published works in the pyrenean orogen that most of the mesoscale deformation has been acquired before layer s tilting

tertiary extension in the southern trento platform southern alps italy the southern trento platform southern alps ne italy was the locus of abundant mafic volcanism associated with paleogene extensional tectonics during the pal eocene and throughout the eocene a nnw sse trending graben the alpone agno graben aag developed in the eastern lessini mountains the graben was filled with basaltic volcaniclastics calcarenites and lava flows the aag is a half graben system probably bounded by rotational listric normal faults most faults in the graben dip towards the wsw paleostress analysis within the aag shows that during the eocene the direction of horizontal extension was ene wsw the volcanic activity continued into the oligocene however the relation between oligocene tectonics and volcanism remains unclear gravimetric and magnetic anomalies in conjunction with the crustal thickness variations suggest a locus of lithospheric thinning slightly off axis from the aag this can be explained by an overall asymmetric extensional geometry dominated by a wsw dipping detachment fault the paleogene geodynamic scenario of the trento platform suggests that the aag developed as a foreland extensional response to the active collisional convergence between the european and adriatic plates neogene compressional tectonics reactivated some of the paleogene normal faults as strike sup faults

kinematic implications of joint zones and isolated joints in the navajo sandstone at zion national park utah evidence for cordilleran relaxation 1 at zion national park znp the landscape is a consequence of differential weathering of the navajo sandstone where closely spaced vertical joints constitute joint zones that erode to form regularly spaced half kilometer slot canyons striking 351 between these joint zones is a set of isolated joints striking 339 fracture interaction and horsetail wing crack development indicate that the 339 striking joint set is younger than the 351 striking joint zones despite the lateral extent of stress reduction shadows in the vicinity of the large scale joint zones in addition to an older less pervasive 020 joint set this sequence of jointing records a counterclockwise rotation of the regional extension directed from wnw to wsw in the navajo sandstone at znp znp is located at the western margin of the colorado plateau 100 km east of the major normal faults of the northeastern central basin and range subprovince extension within the eastern central basin and range initiated during the miocene and exhibited a wsw extension direction anderson 1971 wernicke et al 1988 snow and wernicke 2000 the correlation between nearby basin and range extension and the extension direction for the 351 tending joint zones of znp is so close that the jointing at znp is interpreted as evidence for modest yet pervasive basin and range extension in the western margin of the colorado plateau

a multiscale numerical study of hurricane andrew 1992 part i explicit simulation and verification abstract in this study the inner core structures of hurricane andrew 1992 are explicitly simulated using an improved version of the penn state ncar nonhydrostatic two way interactive movable triply nested grid mesoscale model mm5 a modified betts miller cumulus parameterization scheme and an explicit microphysics scheme were used simultaneously to simulate the evolution of the larger scale flows over the coarser mesh domains the intense storm itself is explicitly resolved over the finest mesh domain using a grid size of 6 km and an explicit microphysics package containing prognostic equations for cloud water ice rainwater snow and graupel the model is initialized with the national centers for environmental prediction analysis enhanced by a modified moisture field a model generated tropical storm like vortex was also incorporated a 72 h integration was made which covers the stages from the storm s initial deepening to a near category 5 hurricane intensity and the landfall over florida as

stress pattern and strain release in the alpine foreland abstract illies j h baumann h and hoffers b 1981 stress pattern and strain release in the alpine foreland in p vyskocil r green and h malzer editors recent crustal movements 1979 tectonophysics 71 157 172 the tectonism of central europe is governed by a generally se nw 140 directed compressive stress flux from the alps towards their northern foreland since alpine folding had relaxed in the late miocene to early pliocene times only to be replaced by high rates of post orogenic uplift these stresses are understood to be of mainly topographic origin the strain release in the foreland is predominantly restricted to pre existing block boundaries shear or extensional movements could come about along those boundaries under the active regional stress regime the rhinegraben which was an extensional rift valley during the eocene to lower miocene has been subjected to a sinistral strike slip motion with shear controlled en echelon faulting on the present surface hydrothermal convection is observed along deep seated fissure systems held open by continuous shear strain since the central segment of the rift caused by its deviatory trend is under compressive shear strike slip motion will be slowed down in the near geological future a parallel shear belt about 100 km e of the rhinegraben became active by changing its function of primary normal faulting this belt characterized locally by high rates of pleistocene movements and some dense clusters of seismic epicenters swings around the impediment to shear which is situated in the central segment of the rhinegraben the shear motion of both belts converging towards the northernmost segment of the rhinegraben is blocked by the rhenish shield which interrupts the extension of the rift system transversally from here on a belt of seismic activity and slight pleistocene normal faulting traverses the shield in the northwesterly direction of maximum horizontal compression crustal rifting is lacking at this segment due to the tectonic incompetency of the prevailing slaty rocks of the hercynian basement to the north of this lithological unit the seismic belt extends to the rift segment of the lower rhine embayment which shows active crustal spreading along discrete dip slip faults

numerical simulations of the genesis of hurricane diana 1984 part i control simulation abstract the complete transformation of a weak baroclinic disturbance into hurricane diana is reproduced by numerical simulations using the fifth generation pennsylvania state university national center for atmospheric research mesoscale model three distinct phases of the evolution are evident first baroclinic and barotropic development strongly modified by the effects of latent heating occurs during the latter part of this phase the low level circulation is strengthened through the axisymmetrization of remote potential vorticity anomalies that are generated by condensational heating and then advected toward the incipient storm the axisymmetrization process evinces properties of both nonlinear discrete vortex merger and vortex rossby wave dynamics the transformation from cold core to warm core vortex occurs in this development stage in the second phase lasting 10 12 h little deepening occurs spiral bands of convection begin to form and the core of the storm moistens eventually reaching 95

a quantitative approach to the dike intrusion process inferred from a joint analysis of geodetic and seismological data for the 1998 earthquake swarm off the east coast of izu peninsula central japan 1 a series of earthquake swarms off the east coast of izu peninsula central japan is typically associated with dike intrusion around active volcanoes numerous studies in this region have documented the seismic activity and ground deformations without fully resolving the process of dike intrusion this study involves a joint analysis of geodetic and seismic data from the most recent major activity in this region occurring in 1998 to reveal the process of dike intrusion quantitatively we combine data from a dense gps array including 10 temporary stations with seismic analysis published previously we estimate the location of the dikes from seismic data and the volume of intruded magma from geodetic data combined analysis of both data sets enables us to reveal the kinematic process of dike intrusion associated with the 1998 earthquake swarm the process of dike intrusion is quantitatively modeled using the time evolution of recorded dike volume and the use of seismic hypocenters as an indicator of the site of instantaneous dike intrusion on the basis of these observations we propose the following process of the dike intrusion the magma rose upward through a pathway aligned vertically and created a dike when it lost buoyancy we also evaluate the dike intrusion process quantitatively using a model of a circular dike that grows under a continuous magma supply from a deep magma reservoir from the observational data we infer the time evolution in the dike shape pressure distribution and magma viscosity in the dike the acquired viscosity increases over time and it may be reasonable because magma cools gradually however its value is too large compared to typical basaltic magma expected in this region it may represent magma within the dike that is nearly solidified otherwise the magma is supplied intermittently and the dike growth is mainly controlled by the magma supply rate from a deep reservoir the quantitative description of the dike intrusion process in nature described in this study is very rare and our results provide constraints on several parameters that have not been solved in many previous theoretical studies on the dike intrusion process

oceanic tides from geosat altimetry direct tidal analysis of the altimetry from the geosat exact repeat mission s first year is used to derive estimates of the diurnal and semidiurnal oceanic tides the geoid is removed by collinear differences at 34 1 day separation and the orbit error is reduced by subtracting a slowly modulated 1 cycle revolution term a sequence of independent analyses at grid areas of 1 latitude 1 5 longitude using orthotide functions ensures complete definition of the diurnal and semidiurnal species global admittance maps for m2 and s2 within the latitudes 58 n and 59 s compare well with ground truth at 66 open ocean sites maps of differences between geosat and the naval surface weapons center model show important areas of the order of 10 15 cm the integral for the global power input from the moon gives 2 51 tw m2 0 44 tw s2 lower than many previous estimates but in agreement with figures deduced from a recent analysis of satellite orbits

orthogonal fracture systems at the limits of thrusting an example from southwestern wales abstract a well developed orthogonal vein system is located in the autochthonous foreland just beyond the limits of variscan thrusting in southwestern wales the two vein sets trend 200 and 290 perpendicular and parallel respectively to variscan structures the veins contain stretched quartz fibers indicating horizontal extensions of between 0 3 and 2 5 the 200 set has greater extension with a distinctive morphology including shorter more curvilinear fractures that have components of normal offset vein intersections are simple indicating episodic growth by alternating regional propagation of each set during propagation maximum compression was subvertical and the horizontal principal stresses switched direction with the alternation of set growth the system formed during waning variscan compression when the directions of horizontal principal stresses were still controlled by the tectonic compression the differential stress may have been greater during propagation of the 200 set this example indicates that orthogonal fracture systems in forelands beyond thrusting 1 are initiated by fracturing parallel to tectonic compression 2 form in a few stages that are controlled by changes in regional stress and 3 form during waning tectonic compression that controls fracture orientations

semidiurnal tides in the northeast atlantic from a finite element numerical model an in time spectral method is used to solve the complete nonlinear problem of tide propagation simultaneously over oceanic and coastal areas for each constituent of the tidal spectrum the corresponding elliptic modal problem is written under a variational form and solved by using a finite element technique the model is applied to the computation of the dominant m2 wave over the northeast atlantic the numerous in situ data over this domain and the large extent of the european continental shelf allow analysis of the gain of accuracy obtained by different components characterizing the model to get a mean accuracy of less than 2 cm and 2 for the amplitudes and phases of the sea surface elevation it is found that 1 the use of a refined mesh over the shallow areas and of a quasi linearized version of the quadratic chezy friction law is essential 2 loading effects computed by means of a green integral have to be taken into account and 3 accurate boundary conditions need to be prescribed at the entrances of dynamically active shallow water areas if they are not included in the investigated area or it is necessary to extend the model over the whole neighboring coastal basin if these boundary conditions are not available from the m2 velocity field solution bottom friction coefficients are derived for the secondary astronomical constituents of the tidal spectrum and accurate charts of the s2 and n2 tides are produced over the modeled area

numerical study of convection observed during the winter monsoon experiment using a mesoscale two dimensional model abstract a two dimensional version of the pennsylvania state university mesoscale model has been applied to winter monsoon experiment data in order to simulate the diurnally occurring convection observed over the south china sea the domain includes a representation of part of borneo as well as the sea so that the model can simulate the initiation of convection also included in the model are parameterizations of mesoscale ice phase and moisture processes and longwave and shortwave radiation with a diurnal cycle this allows use of the model to test the relative importance of various heating mechanisms to the stratiform cloud deck which typically occupies several hundred kilometers of the domain frank and cohen s cumulus parameterization scheme is employed to represent vital unresolved vertical transports in the convective area the major conclusions are ice phase processes are important in determining the level of maximum large scale heating and vertical motion because there is a strong anvil componen

regional stress field and rifting in western europe abstract baumann h 1981 regional stress field and rifting in western europe in j h illies editor mechanism of graben formation tectonophysics 73 105 111 in situ stress determination is one possibility to determine stress magnitudes in the earth s crust most measurements especially in the northern alpine foreland have been carried out by using the doorstopper technique stress magnitudes are presented as excess stresses a number of sites where stresses have been determined gave sufficiently high values to statistically determine stress directions for the following tectonic blocks 1 western alps 2 their immediate foreland with the rhinegraben and 3 the rhenish shield bordering on the rift segment of the lower rhine embayment in discussing results of the statistical analyses of stress data it is suggested that stresses measured in the western alps have mainly a topographic origin in the alpine foreland to the north of the rhenish shield topographic stresses are superimposed on active tectonic stress considering the structural and lithological differences the foreland blocks show a different response to the same tectonic stress field which trends for 1 at about 146 this active stress field causes shear rifting in the upper rhinegraben but extensional rifting in the lower rhine embayment in the rhenish shield area only local step faults are observed in direction of 1 due to the ductile behaviour of its basement

the west european stress field new data and interpretation abstract the mapped stress field of western europe reflects the tectonic process active there a traverse of stress measurements from the alps and through their northern foreland to the southern border of the lower rhine embayment identifies three distinct stress sub provinces the western alps the blocks on both flanks of the rhinegraben and the rhenish shield the alps have high magnitude stresses up to 35 mpa in the direction of maximum compression here called 1 h the general direction of 1 h is about 140 the foreland has the same directional trend of 1 h with a magnitude reduced to about 2 0 mpa local anomalies in magnitude and direction occur along the course of the rhinegraben which is a site of active sinistral shear the rhenish shield shows an internal zonation of the stress field the magnitudes of the stresses are low usually negative along the axis connecting the northern end of the rhinegraben with the rifting of the lower rhine embayment the direction there is about 150 on the eastern and western flanks of the shield the stress directions are essentially the same as in the southern blocks these zones are distant from the belt of active strain release consequently stresses of up to 4 0 mpa have accumulated

a seismic refraction study of the western tuz golu basin central turkey summary in 1970 the turkish petroleum company carried out a seismic refraction experiment in the tuz golu salt lake basin of central turkey we present our interpretation using time term analysis and ray tracing of data from one of the two lines shot this confirms the presence of a thick sequence of sedimentary layers varying from about 3 km below the southwestern end of the profile to about 10 km at two points along the line a p wave velocity of 4 0 4 2 km s 1 found beneath the low velocity surface layer indicates that the principal sedimentary layer consists of evaporites the lowermost layer of the model has a p wave velocity of 6 15 km s 1 which is consistent with the sedimentary layers being underlain either by cretaceous metamorphic basement or by lavas of andesitic type the extensive coverage provided by this data set has enabled the construction of a detailed 2 d model which shows the complex topography of the subsurface layers we identify two major faults and one minor fault affecting both the basement and overlying layers the character of these features and the associated layer displacements leads us to speculate that these may be growth faults associated with the aksaray ereflikochisar and karapinar cihanbeyli haymana hinge structures which have controlled the development of the tuz golu basin