miocene transgression in the central and eastern parts of the sivas basin central anatolia turkey and the cenozoic palaeogeographical evolution we present here a reappraisal of the tectonic setting stratigraphy and palaeogeography of the central part of the sivas basin from palaeocene to late miocene the sivas basin is located in the collision zone between the pontides southern eurasia and anatolia a continental block rifted from gondwana the basin overlies ophiolites that were obducted onto anatolia from tethys to the north the central anatolian crystalline complex cacc experienced similar ophiolite obduction during campanian time followed by exhumation and thrusting onto previously emplaced units during maastrichtian time to the east crustal extension related to exhumation of the cacc created grabens during the early tertiary including the sivas basin the sivas basin underwent several tectonic events during paleogene neogene the basin fill varies with several sub basins each being characterised by a distinctive sequence especially during oligocene and miocene evaporite deposition in the central part of the basin during early oligocene was followed by mid late oligocene fluvio lacustrine deposition the weight of overlying fluvial sediments triggered salt tectonics and salt diapir formation lacustrine layers that are interbedded within the fluviatile sediments have locally yielded charophytes of late oligocene age emergent areas including the pre existing sivas basin and neighbouring areas were then flooded from the east by a shallow sea giving rise to a range of open marine sub basins coralgal reef barriers and subsiding restricted marine sub basins utilising new data from foraminifera molluscs corals and nannoplankton the age of the marine transgression is reassessed as aquitanian specifically age diagnostic nannoplankton assemblages of classical type occur at the base of the transgressive sequence however classical stratigraphic markers have not been found within the planktic foraminiferal assemblages even in the open marine settings in the restricted marine sediments there are rich planktic foraminiferal assemblages of classical type but these are of little use in stratigraphy in contrast the gastropod fauna indicate a burdigalian age sediment reworking in the restricted marine environments precludes stratigraphic determination in such environments micro and nano organisms experienced atypical developmental conditions the small benthic foraminifera and associated ostracod assemblages are good indicators of salinity which varied considerably within the restricted marine sub basins some of the corals within the coralgal reefs barriers are also dated as aquitanian a combination of the salt tectonics and the late miocene north westward verging thrusting created the present basin complexity

rate of strike slip motion on the amanos fault karasu valley southern turkey constrained by k ar dating and geochemical analysis of quaternary basalts the left lateral amanos fault follows a 200 km long and up to 2 km high escarpment that bounds the eastern margin of the amanos mountain range and the western margin of the karasu valley in southern turkey just east of the northeastern corner of the mediterranean sea regional kinematic models have reached diverse conclusions as to the role of this fault in accommodating relative motion between either the african and arabian turkish and african or turkish and arabian plates local studies have tried to estimate its slip rate by k ar dating quaternary basalts that erupted within the amanos mountains flowed across it into the karasu valley and have since become offset however these studies have yielded a wide range of results ranging from 0 3 to 15 mm a 1 which do not allow the overall role and significance of this fault in accommodating crustal deformation to be determined we have used the cassignol k ar method to date nine quaternary basalt samples from the vicinity of the southern part of the amanos fault these basalts exhibit a diverse chemistry which we interpret as a consequence varying degrees of partial melting of their source combined with variable crustal contamination this dating allows us to constrain the quaternary slip rate on the amanos fault to 1 0 to 1 6 mm a 1 the dramatic discrepancies between past estimates of this slip rate are partly due to technical difficulties in k ar dating of young basalts by isotope dilution in addition previous studies at the key locality of hacilar have unwittingly dated different chemically distinct flow units of different ages that are juxtaposed this low slip rate indicates that at present the amanos fault takes up a small proportion of the relative motion between the african and arabian plates which is transferred southward to the dead sea fault zone it also provides strong evidence against the long standing view that its slip continues offshore to the southwest along a hypothetical left lateral fault zone located south of cyprus

no surface breaking on the ecemis fault central turkey since late pleistocene 64 5 ka new geomorphic and geochronologic data from cosmogenic dating of offset alluvial fans abstract the ecemis fault zone ef has been recognized as a major left lateral strike slip fault in the central anatolian fault zone cafz of turkey however its quaternary slip rate has been challenging to determine due to the difficulty of dating offset markers using high precision offset measurements and 36 cl cosmogenic nuclide dating we present the first geochronologically determined late quaternary slip rate for the ef our study focuses on the excellent exposures of offset alluvial fan surfaces originating from the aladaglar a late quaternary glaciated mountain analysis of airborne orthophotogrametry and gnss global navigation satellite system surveys indicates 168 2 m left lateral and 31 1 m vertical displacements in situ terrestrial cosmogenic 36 cl geochronology obtained from eleven surface boulders provides a minimum abandonment incision age of 104 2 16 5 ka for the oldest offset alluvial fan surface our geomorphic observations together with self potential geophysical surveys revealed the presence of an unfaulted alluvial fan terrace which allows us to constrain the timing of deformation the abandonment incision age of this fan is 64 5 5 6 ka based on thirteen 36 cl depth profile samples accordingly we obtained a geologic fault slip rate of 4 2 1 9 mm a 1 horizontally and 0 8 0 3 mm a 1 vertically for the time frame between 104 2 16 5 ka and 64 5 5 6 ka our analysis indicates that the ef has not been producing a major surface breaking earthquake on the main strand at least since 64 5 5 6 ka mid late pleistocene this could be the result of abandonment of the main strand and accommodation of deformation by other faults within the ef nevertheless a recently occurred 30 september 2011 low magnitude ml 4 3 left lateral strike slip earthquake indicates recent seismic activity of the ef comparison of the recent gps velocity field with the longer slip history along the cafz indicates a constant but low strain release without surface breaking and very long large earthquake recurrence intervals

automated fault model discretization for inversions for coseismic slip distributions 1 geoscientists increasingly rely on coseismic slip distributions inferred from geodetic observations to drive sophisticated models of the seismic cycle to date little work has been done on optimizing the parameterization of these fault models so that they reflect the resolving power of observed surface displacements the locations of noisy surface displacement observations are often widely scattered far from features we wish to analyze in the subsurface and result in highly variable model resolution with depth the few attempts to produce variably discretized fault planes are arduously constructed by hand and may not correctly reflect the ability of the data to resolve slip features motivated by the increasing size of geodetic data pools and the need for distributed slip models that accurately represent features the data can resolve we present a fully automated algorithm that iteratively adjusts the sizes of dislocations in a fault model we use the concept of smoothing scales derived from the model resolution matrix to resize dislocations so that each dislocation is sized appropriately given the area over which slip in that region of the fault would be smoothed we present a series of synthetic tests that utilize both sparse and dense data sets and we compare our variably discretized inversions to traditional regularly discretized inversions we also use our approach to invert for slip from geodetic observations of the 2004 mw 6 0 parkfield california earthquake and the 1995 mw 8 1 antofagasta chile earthquake

strain and rotation rate from gps in tibet anatolia and the altiplano 1 deformation measured by regional gps networks in continental plateaus reflects the geologic and tectonic variability of the plateaus for two collisional plateaus tibet and anatolia and one noncollisional the altiplano we analyze the regional strain and rotation rate by inverting gps velocities to calculate the full two dimensional velocity gradient tensor to test the method we use gridded velocities determined from an elastic block model for the eastern mediterranean middle east region and show that to a first order the deformation calculated directly from the gps vectors provides an accurate description of regional deformation patterns principal shortening and extension rate axes vertical axis rotation and two dimensional 2 d volume strain dilatation are very consistent with long term geological features over large areas indicating that the gps velocity fields reflect processes responsible for the recent geologic evolution of the plateaus differences between geological and gps descriptions of deformation can be attributed either to gps networks that are too sparse to capture local interseismic deformation or to permanent deformation that accrues during strong earthquakes the altiplano has higher internal shortening magnitudes than the other two plateaus and negative 2 d dilatation everywhere vertical axis rotation changes sign across the topographic symmetry axis and is due to distributed deformation throughout the plateau in contrast the collisional plateaus have large regions of quasi rigid body rotation bounded by strike slip faults with the opposite rotation sense from the rotating blocks tibet and anatolia are the mirror images of each other both have regions of positive dilatation on the outboard sides of the rotating blocks positive dilatation in the aegean correlates with a region of crustal thinning whereas that in eastern tibet and yunnan province in china is associated with an area of vertical uplift rollback of the hellenic trench clearly facilitates the rotation of anatolia rollback of the sumatra burma trench probably also enables rotation about the eastern syntaxis of tibet

cenozoic evolution of neotethys and implications for the causes of plate motions africa north america eurasia plate circuit rotations combined with red sea rotations and new estimates of crustal shortening in iran define the cenozoic history of the neotethyan ocean between arabia and eurasia the new constraints indicate that arabia eurasia convergence has been fairly constant at 2 to 3 cm yr since 56 ma with slowing of africa eurasia motion to 1 cm yr near 25 ma coeval with the opening of the red sea ocean closure occurred no later than 10 ma and could have occurred prior to this time only if a large amount of continental lithosphere was subducted suggesting that slowing of africa significantly predated the arabia eurasia collision these kinematics imply that africa s disconnection with the negative buoyancy of the downgoing slab of lithosphere beneath southern eurasia slowed its motion the slow steady rate of northward subduction since 56 ma contrasts with strongly variable rates of magma production in the urumieh dokhtar arc implying magma production rate in continental arcs is not linked to subduction rate

surface wave phase velocity maps of the anatolia region turkey from ambient noise tomography abstract the anatolian region is an area with very heterogeneous crustal structure accompanied by large velocity contrasts despite the complexity of the region the detailed crustal structure remains to be unraveled in this study we first measure the dispersion curves of rayleigh waves between 1 721 pairs of station and then invert these dispersion curves to obtain high resolution isotropic and azimuthally anisotropic phase velocity maps in the period range of 5 25 s the resulting isotropic phase velocity patterns display strong correlation with the geological features while the anisotropic patterns are highly consistent with the gps measured surface velocity field in the region variations of the isotropic as well as anisotropic patterns indicate the presence of active faulting especially beneath the east and north anatolian faults beneath the locations of holocene volcanoes and crystalline massifs in cappadocia high velocities up to 2 5 are present whereas negative velocity anomalies up to 2 are found beneath the menderes massif in southwestern anatolia at periods of 5 20 s suggesting different origins and tectonic regimes of those massifs on either side of an active fault two terranes with different stress patterns are generally found active fault can thus be identified by different anisotropy patterns on either sides of the fault the central anatolian fault do not display strong isotropic velocity contrasts as well as no noticeable variation in the anisotropic pattern across the fault suggesting that this fault may not be active in recent times

combining impedance inversion and seismic similarity for robust gas hydrate concentration assessments a case study from the krishna godavari basin east coast of india abstract gas hydrate saturations were calculated based on archie s relation and rock physics modeling utilizing log measurements of electrical resistivity and p wave velocity through the gas hydrate stability zone ghsz at two sites in the krishna godavari kg basin off the east coast of india acoustic impedance inversion was then performed around the well sites for regional extrapolation of the borehole data well log based gas hydrate concentration estimates and core data are in general agreement with the seismic impedance inversion results at the individual well sites however the correlation with seismic data and thus the confidence in the extrapolation decreases with distance from the well site to address the general problem of unknown regional confidence limits in the extrapolation and aid in regional gas hydrate assessment analyses a new approach is introduced by calculating the running sum of the seismic similarity attribute across the gas hydrate stability zone the running sum of the similarity attribute can be used locally on a 2d seismic line or 3d seismic volume for defining the limit of well data extrapolation around a given well site by normalizing the running sum of the similarity attribute from all available 2d seismic data in the kg basin a regional map was generated yielding effective confidence limits for extrapolation of well log data such maps of regional confidence limits can be used strategically in basin wide gas hydrate assessments as they provide a measure of probability to find a given gas hydrate concentration and may also offer a guide for defining a minimum regional spacing between well sites to address the overall structural complexity of the basin which is reflected in the similarity of the seismic data

new kinematic and geochronologic evidence for the quaternary evolution of the central anatolian fault zone cafz as the kinematics of active faults that bound the anatolian plate are well studied it is now essential to improve our understanding of the style and rates of intraplate deformation to constrain regional strain partitioning and improve seismic risk assessments one of these internal structures the central anatolian fault zone cafz was originally defined as a regionally significant left lateral tectonic escape structure stretching for 700 km in a ne direction across the anatolian plate we provide new structural geomorphic and geochronologic data for several key segments within the central part of the cafz that suggest that the sinistral motion has been overstated the ecemis fault the southernmost part of the cafz has a late quaternary minimum slip rate of 1 1 0 4 mm a 1 slower than originally proposed farther north the erciyes fault has fed a linear array of monogenetic vents of the erciyes stratovolcano and 40ar 39ar dating shows a syneruptive stress field of ese wnw extension from 580 130 ka to 210 180 ka in the erciyes basin and central part of the cafz we mapped and recharacterized the erkilet and gesi faults as predominantly extensional these long term geological rates support recent gps observations that reveal ese wnw extension which we propose as the driver of faulting since 2 73 0 08 ma the slip rates and kinematics derived in this study are not typical of an escape tectonic structure the cafz is a transtensional fault system that reactivates paleotectonic structures and accommodates e w extension associated with the westward movement of anatolia

present day kinematics of the middle east and eastern mediterranean the middle east and eastern mediterranean regions contain three major strike slip fault zones the dead sea fault zone dsfz and the north and east anatolian fault zones nafz and eafz these accommodate northward motion of the african and arabian plates relative to eurasia and westward motion of the small turkish plate this study deduces an internally consistent solution for the present day kinematics of these plates which is accurate to better than 20 and applicable throughout time since 5 ma by constraining the slip senses and rates on these strike slip fault zones the 7 0 5 mm yr 1 left lateral slip rate on the dsfz is associated with counterclockwise rotation of arabia relative to africa at 0 33 m y 1 around an eulcr pole near 33 n 23 e the nafz takes up counterclockwise rotation of the turkish plate relative to eurasia at 0 83 m y 1 13 around a pole at 31 n 35 5 e with right lateral slip rate 15 mm yr 1 the resulting prediction for the eafz involves 14 mm yr 1 left lateral motion and 2 mm yr 1 of shortening between arabia and turkey the triple junction of africa arabia and turkey is near the city of kahramanmaras this locality contains a narrow promontory bounded by ssw trending left lateral faults at the edges of the arabian and turkish plates which is loosely attached to the african plate moving westward relative to its interior at 4 mm yr 1

global scale p wave tomography optimized for prediction of teleseismic and regional travel times for middle east events 2 tomographic inversion 1 we construct a model of three dimensional p wave velocity structure in the crust and mantle that is global in extent but with detailed upper mantle heterogeneities throughout the greater middle east region fully three dimensional ray tracing is employed to achieve accurate travel time predictions of p and pn arrivals requiring the characterization of irregular and discontinuous boundaries therefore we explicitly represent undulating seismic discontinuities in the crust and upper mantle within a spherical tessellation modeling framework the tessellation based model architecture is hierarchical in that fine node sampling is achieved by recursively subdividing a base level tessellation determining the required node spacing to effectively model a given set of data is problematic given the uneven sampling of seismic data and the differing wavelengths of actual seismic heterogeneity to address this problem we have developed an inversion process called progressive multilevel tessellation inversion pmti that exploits the hierarchical nature of the tessellation based design and allows the data to determine the level of model complexity pmti serves as an alternative to existing multiresolution approaches and robustly images regional trends while allowing localized details to emerge where resolution is sufficient to demonstrate our complete modeling concept we construct a velocity model based on teleseismic p travel time data for global events and regional pn travel time data for events occurring throughout the middle east input data are a product of the statistical procedure called bayesloc that simultaneously models all components of a multievent system including event locations origin times and arrival times described in the myers et al 2011 companion paper the initial tomographic image provides a new glimpse of the complex upper mantle velocity anomalies associated with the convergence of the arabian and indian plates with eurasia more important for event monitoring the model accurately predicts both teleseismic and regional travel times for events occurring within the middle east region

the structural relationship between the east anatolian and dead sea fault zones in southeastern turkey abstract the complex structural relationship between the east anatolian and dead sea fault zones is examined mostly based on field observations in southeastern turkey where the two fault zones are close together several faults previously poorly documented can be traced to connect either to the east anatolian fault zone or to the dead sea fault zone one of these faults connects the dead sea fault zone to the east to the amanos fault to the west the amanos fault a n trending normal fault is a part of the east anatolian fault zone since it is apparently a left step fault between the main and southern strands of the east anatolian fault zone the dead sea fault zone also is connected to the east anatolian fault zone northeast of the town of narli and or northeast of the hazar lake therefore we suggest that the two fault zones can be considered as one broad fault system in southeastern turkey although they are well recognized as two different fault zones this fault system is responsible for several complex neogene structural features of the western part of the southeastern turkey one of these is the hatay graben which can be divided into southern central and northern parts the graben contains down to the west normal faults in its southern part the central part of the graben is a divergent strike slip basin and the northern part is a half graben

coseismic and initial postseismic deformation from the 2004 parkfield california earthquake observed by global positioning system electronic distance meter creepmeters and borehole strainmeters global positioning system gps electronic distance meter creepmeter and strainmeter measurements spanning the m 6 0 parkfield california earthquake are examined using these data from 100 sec through 9 months following the mainshock the omori s law with rate inversely related to time 1 t p and p ranging between 0 7 and 1 3 characterizes the time dependent deformation during the postseismic period these results are consistent with creep models for elastic solids with an accurate function of postseismic response the coseismic displacements can be estimated from the high rate 1 min sampling gps and the coseismic displacements are approximately 75 of those estimated from the daily solutions consequently fault slip models using daily solutions overestimate coseismic slip in addition at 2 months and at 8 months following the mainshock postseismic displacements are modeled as slip on the san andreas fault with a lower bound on the moment exceeding that of the coseismic moment online material data description and supplementary figures tables and data used in models and time series analysis

geodynamic importance of the strike slip faults at the eastern part of the anatolian scholle inferences from the uplift and slip rate of the malatya fault malatya ovacik fault zone eastern turkey abstract controversy remains over when present day configuration of the anatolia boundary faults came into existence and the issue of what are the driving forces of the anatolian westward motion the nw striking dextral and ne striking sinistral second order strike slip faults at the eastern part of the anatolian scholle play a crucial role within these long lasting discussions and the ne striking sinistral malatya ovacik fault zone mofz is particularly important in this ongoing debate although the mofz is defined as one of the intra plate structures it has been proposed that it was an inter plate fault between the anatolia and arabian plates from the latest miocene to mid pliocene and that it has been inactive during the last ca 3 5 ma this study provides results from the first morphochronology based uplift and slip rate estimates on the malatya fault within the southern section of the mofz the cosmogenic isochron burial and cosmogenic depth burial of ages from the sinistrally offset tohma river remnant terraces enabled us to calculate 1 0 0 01 and 1 12 0 01 mm yr minimum and maximum horizontal slip rates respectively for the last 1 4 0 1 ma furthermore we conclude that the 96 11 m ma mean uplift has been driven by the malatya fault integrated interpretation of the findings of this study and available data on both the mofz and other strike slip faults at the eastern part of the anatolian scholle support the hypothesis that they are plate boundary related active deformation belts that originated from paleotectonic structures during the tectonic escape of the anatolian scholle

a new intracontinental transcurrent structure the central anatolian fault zone turkey abstract recent neotectonic studies including remote sensing aerial photographs geological field mapping on various scales and measured stratigraphic section substantiate the existence of a large sinistral intracontinental transcurrent structure which we call the central anatolian fault zone cafz this is an approximately 730 km long 2 km to 80 km wide ne trending active sinistral strike slip fault zone that cuts across the anatolian plateau between duzyayla in the northeast and anamur county in the southwest it continues onward beneath the eastern mediterranean sea and determines the boundary of the antalya and adana basins as far as to the west of cyprus the cafz is a very young neotectonic structure it resulted from the reactivation and propagation of an older paleotectonic structure the so called ecemi s corridor in both nne and sw directions across the inner tauride suture in the plio quaternary times based on geometric discontinuities the cafz is divided into 24 segments each of them is characterized by a number of strike slip morphotectonic features reflecting recent motions the easternmost part of the anatolian platelet is being deformed internally by several dextral to sinistral intraplate strike slip faults these are the lake salt fault zone lsfz the salanda fault sf the cafz the goksu yazyurdu fault zone gyfz and the malatya ovacik fault zone mofz they take up lesser motion and are younger than boundary faults of the anatolian platelet the gyfz and mofz splay from the natf cut across the anatolian platelet and then meet to the eatf whereas other faults are confined into the anatolian platelet and seem to be independent structures however present day structural pattern of all these intraplate faults and boundary faults of the anatolian platelet indicates a regional strain pattern of nnw sse directed shortening and ene wsw directed extension and they seem to have developed to accommodate northward motion of the arabian plate since late early pliocene times

locations of selected small earthquakes in the zagros mountains the zagros mountains of southern iran are marked by a zone of high seismicity and accommodate a significant portion of the convergence between arabia and eurasia due to the lack of dense local seismic or geodetic networks the inferred kinematics of the collision in iran is mainly based on catalogs of teleseismically determined earthquake locations we surveyed all mw 4 5 earthquakes in the harvard centroid moment tensor hcmt and international seismological centre isc catalogs that occurred in the zagros mountains during the period 1992 2002 and that were spanned by interferometric synthetic aperture radar insar images from the ers 1 and 2 satellites we invert the observed deformation for the best fitting point source single fault plane and distributed fault slip for four earthquakes and one unexplained deformation event we find that we can precisely locate earthquakes that are too small to be well located by either the hcmt or isc catalogs allowing us to tie specific earthquakes to active geologic structures

palaeomagnetism of the cappadocian volcanic succession central turkey major ignimbrite emplacement during two short miocene episodes and neogene tectonics of the anatolian collage abstract the central anatolian volcanic province in cappadocia includes 13 high volume calc alkaline ignimbrite sheets emplaced by plinian eruptions within a succession the urgup formation after 10 ma recording the last phase of neotethyan subduction and accompanying emplacement of the tauride orogen in southern turkey to evaluate magnetostratigraphy in the context of recent revisions of the chronostratigraphy we have extended palaeomagnetic investigation to 32 new sites yielding significant chrm directions integrated rock magnetic and palaeomagnetic investigations identify magnetic remanence residing predominantly in ti poor titanomagnetites although secondary processes within the ignimbrite sheets notably post emplacement oxidation have locally produced hematisation expressed by composite irm spectra and variable reduction in intensity of magnetisation the ignimbrite sheets possess weak anisotropies of magnetic susceptibility ams mostly 3 of pyroclastic deposits during polarity chron c4r 1n between 9 31 and 9 43 ma subsequent activity from the acigol centre further to the south west cemilkoy gelveri gordeles and kizilkaya produced in excess of 620 km 3 of pyroclastic deposits during polarity chrons between 5 3 and 7 1 ma the younger incesu ignimbrite was sourced in the sultansazligi pull apart basin to the east during the gauss chron 2 58 3 60 ma all pre incesu ignimbrites are rotated uniformly anticlockwise and the overall reversed group mean direction of magnetisation is d i 170 8 52 4 n 9 r 8 91 95 5 4 k 91 the implied tectonic rotation in this sector of central anatolia 16 4 relative to eurasia is young and postdates the 5 3 7 1 ma acigol centre whilst largely predating emplacement of the incesu ignimbrite whilst rotational deformation within anatolia is young it proves to be distributed with a temporal variation from block to block it is embraced by a complex post miocene tectonic regime of strike slip and extension during tectonic escape and suction towards the hellenic arc to the west

kinematic consistency between the dead sea fault zone and the neogene and quaternary left lateral faulting in se turkey a revised quantitative kinematic model has been determined for the dead sea fault zone dsfz and the left lateral fault zones in se turkey the relative motions of the african and arabian plates across the dsfz are represented by relative rotation about 31 1 n 26 7 e at 0 40 0 02 ma 1 the northern dsfz in syria and southern turkey is interpreted for the first time as a series of transpressional stepovers along which the left lateral slip rate is substantially less than the rate of relative plate motion because this slip is oblique to the plate motion the slip rate on the east anatolian fault zone eafz is estimated as 8 mm a 1 restoring its observed slip thus requires its age to be 4 ma the previous phase of deformation which involved slip on the malatya ovacik fault zone mofz before the eafz came into being is thus dated to 7 4 ma suggesting initiation of the north anatolian fault zone nafz at 7 ma not 5 ma as previously thought the total left lateral slip on the northern dsfz in southernmost turkey is estimated as at least 65 km partitioned with 45 km on the amanos fault 10 km on the east hatay fault and a further 10 km on the kirkpinar fault farther east much of this slip is inferred to have occurred during the miocene before the modern geometry of this plate boundary zone developed when it first formed the af ar plate boundary was relatively complex it initially reactivated preexisting structures in the palmyra foldbelt in syria and in the gaziantep region of southern turkey which were significantly misaligned relative to the plate motion requiring major components of shortening as well as left lateral slip the transition from this initial rather diffuse geometry to the present localised geometry of the dsfz across western syria occurred within the miocene the predicted rate of relative motion between the stable interiors of the turkish and african plates in the vicinity of their common boundary onshore of iskenderun gulf in southern turkey is estimated as westward at 9 mm a 1 however this promontory of the african plate is itself moving westward relative to the stable interior of this plate at 7 8 mm a 1 the rate of localised left lateral slip on the onshore part of this boundary the ne trending yakapinar goksun fault is thus estimated as only 2 mm a 1 this locality can also be regarded as within the distributed boundary zone between the turkish and arabian plates the estimated relative motion between these plates is at 8 7 mm a 1 towards the ssw partitioned between localised left lateral slip at 2 mm a 1 on the yakapinar goksun fault and at least 1 mm a 1 on the amanos fault and 2 5 mm a 1 on east hatay fault with at most distributed left lateral simple shear at 3 2 mm a 1 across the amanos mountains in between however the combined slip on left lateral faults east of the amanos mountains may be as high as 6 mm a 1 with slip at 1 7 mm a 1 on the amanos fault and at 4 3 mm a 1 on the east hatay fault and any active faults farther east this requires no more than 0 7 mm a 1 of distributed simple shear across the amanos mountains raising the possibility that this component of deformation may in fact be zero this small nonzero estimate possibly indicating a closure error arising from minor errors in predicted values of other relative motion vectors it is proposed that this boundary between the turkish and african plates first developed at the same time as the mofz and nafz but its original geometry involving left lateral slip on the karatas osmaniye fault has since become locked by the presence of relatively strong ophiolitic crust within this fault zone this quantitative kinematic model demonstrates for the first time how it is possible for the left lateral faulting accommodating the nnw sse relative motion between the arabian and african plates in nw syria to dovetail into the left lateral faulting accommodating the wsw ene relative motion between the turkish and arabian plates in se turkey

tectonic connection of the hellenic and cyprus arcs and related geotectonic elements abstract the cyprus arc system forms part of a well defined presently active plate boundary and is a critical area for understanding the evolution of the eastern mediterranean sea the available seismic reflection profiles are utilised in order to establish the nature and origin of the main tectonic features of the arc which include 1 a the cyprus trench displaying evidence of underthrusting and morphostructural features typical of subduction zones 2 b the pytheus trench associated with right lateral strike slip movement and connecting the western end of the cyprus trench to the strabo trench sector of the hellenic trench system 3 c a predominantly transtensional fault zone connecting the easternmost part of the cyprus trench via the baer bassit overthrust zone in syria to the dead sea transform fault system 4 d a zone of complex deformation involving thrust and transform elements running from the misis mountains of southeast turkey through the kyrenia range in cyprus to the gulf of antalya and transected by roughly n s major shears notably the cape gelidonya anaximander mountains strike slip zone which appears to form the western boundary of the present active system of the cyprus arc the nature of the shallow structures associated with the cyprus arc is consistent with a geotectonic model involving some post miocene rotation of the south anatolian cyprus block probably induced by escape dynamics resulting from continent continent collision in eastern turkey and the development of the maras triple junction in southeastern turkey the alternation of plate boundary sectors respectively characterised by thrusting and strike slip displacement suggests that the shallow crust in this part of the eastern mediterranean is in a compartmented and relatively brittle state allowing accumulated boundary stresses to be accommodated largely by displacements and deformation along secondary features

regional trends in active diapirism revealed by mountain range scale insar time series 1 we construct an orogen wide insar time series over the zagros mountains and eastern markan subduction zone in southern iran from 19 envisat tracks spanning 2003 2010 we observe active salt diapirism of the infra cambrian hormuz salt at 20 locations and identify several diapirs that are not moving all active diapirs reach the surface within the asmari limestone or older rock units while we do not observe any active diapirism occurring within younger exposures reflecting a complex vertical accumulation of the basal salt and reactivation of diapirs by erosion diapir reactivation of this sort may be a critical factor affecting the feasibility of sequestering nuclear waste and co2 in evaporite sequences over geologic time scales the distribution of active diapirism is indifferent to increases in mean elevation suggesting a relatively uniform thickness of the zagros fold belt above the basal salt with steps in topography driven by basement thickening we do not observe aseismic uplift of anticlines because rates are likely below the detection threshold of our time series this suggests that uplift is accommodated at small rates 2 3 mm yr over numerous structures instead of focused at the deformation front

the golbaoi basin southeastern turkey a complex discontinuity in a major strike slip fault zone we show that the 33 km long golbaoi basin on the east anatolian fault zone marks the triple junction between the african arabian and turkish plates the main strand of the turkish arabian plate boundary the goksu fault enters this basin from the ene before splaying to form faults which develop farther southwest into the turkish african and african arabian boundaries the golba i turko u fault the turkish african boundary is shown to have slipped 16 km the prevously unrecognised kirkpmar fault the african arabian boundary has slipped 17 km we propose that this fault geometry developed at c 3 ma following earlier slip starting at c 5 ma on other strike slip faults nearby which marked the start of westward motion of the turkish plate

some thoughts on the use of insar data to constrain models of surface deformation noise structure and data downsampling repeat pass interferometric synthetic aperture radar insar provides spatially dense maps of surface deformation with potentially tens of millions of data points here we estimate the actual covariance structure of noise in insar data we compare the results for several independent interferograms with a large ensemble of gps observations of tropospheric delay and discuss how the common approaches used during processing of insar data affects the inferred covariance structure motivated by computational concerns associated with numerical modeling of deformation sources we then combine the data covariance information with the inherent resolution of an assumed source model to develop an efficient algorithm for spatially variable data resampling or averaging we illustrate these technical developments with two earthquake scenarios at different ends of the earthquake magnitude spectrum for the larger events our goal is to invert for the coseismic fault slip distribution for smaller events we infer the hypocenter location and moment we compare the results of inversions using several different resampling algorithms and we assess the importance of using the full noise covariance matrix

phantom earthquakes and triggered aseismic creep vertical partitioning of strain during earthquake sequences in iran 1 we present evidence for significant aseismic fault slip at shallow depth above a pair of mainshock aftershock sequences in the zagros mountains of iran the two mw 5 9 earthquakes are each spanned by high quality geodetic imagery and have well recorded sequences of aftershocks that occurred beneath a salt decollement earlier studies of the geodetic data inferred that the mainshocks were located above the decollement requiring a 10 km spatial separation between aftershock cluster and earthquake centroid we find that the geodetic data simultaneously allow two slip sources of similar magnitude one within the basement collocated with aftershocks and one shallow source also equivalent to mw 6 responsible for the primary signal apparent in the geodetic imagery should this phenomenon be widespread in the zagros it would partially explain a previously noted discrepancy between observed seismic moment release in the zagros and current convergence rates between the arabian and eurasian plates

metamorphism of the central anatolian crystalline complex turkey influence of orogen normal collision vs wrench dominated tectonics on p t t paths the central anatolian crystalline complex cacc is a microcontinent in the alpine himalayan belt it has previously been considered as a coherent structural entity but although the entire cacc is comprised of similar rocks primarily metasedimentary rocks and granitoids it consists of at least four tectonic blocks characterized by different p t t paths these blocks are the kirsehir north west akdag north east nigde south and aksaray west massifs the northern massifs experienced thrusting and folding during collision and were slowly exhumed by erosion metamorphic rocks are characterized by clockwise p t paths at moderate p t and local low p high t lp ht overprinting in the highest grade rocks apatite fission track ages are eocene to oligocene 47 32 ma the aksaray block represents the hot shallow mid crust of a late cretaceous early tertiary arc it is dominated by intrusions rare metapelitic rocks record low p 4 kbar regional metamorphism overprinted by lp ht contact metamorphism apatite fission track ages are 50 45 ma the nigde massif is different from the other cacc blocks because it evolved as a core complex in a wrench dominated setting it is characterized by clockwise p t paths at moderate p t followed by widespread lp ht metamorphism apatite fission track ages are miocene 12 9 ma significantly younger than those in the northern massifs nigde rocks resided in the mid crust at a time when the rest of the cacc was at or near the earth s surface variations in p t t and tectonic histories especially timing of exhumation between the northern and southern cacc reflect the difference between head on collision vs mid crustal wrenching

depths and focal mechanisms of crustal earthquakes in the central andes determined from teleseismic waveform analysis and insar 1 we investigate the depths of crustal earthquakes mw 5 5 earthquakes from the global cmt catalog and previous work spanning 1944 2007 for 38 well recorded events we use teleseismic p and sh waveforms to model the strike dip rake focal depth and source time function we use insar observations of surface deformation from 9 earthquakes to compare inferred fault parameters with the waveform inversions and global catalogs to assess their accuracies while the depths from the insar and waveform analyses generally agree within error horizontal and depth errors in global catalogs are 10 to 50 km as found elsewhere as noted in previous work the majority of crustal earthquakes occur in the eastern cordillera and foreland regions of the central andes although a few normal and strike slip earthquakes occur beneath the altiplano plateau and in the forearc in southern peru and northernmost chile we propose a new interpretation of one of the basement thrusts shira mountain peru as a pop up block on the basis of our new earthquake depths we confirm that earthquakes in the flat slab areas of peru and argentina are within the sometimes aseismic lower crust lower crustal earthquakes are globally found in all types of tectonic settings only when the thermal lithosphere is more than 80 km thick and the amount of recent shortening extension is 30

comment on a new intracontinental transcurrent structure the central anatolian fault zone turkey by a kocyigit and a beyhan abstract kocyigit and beyhan have described the central anatolian fault zone cafz as a 700 km long active strike slip fault zone in turkey if their interpretation is correct then several major turkish cities are vulnerable to a significant earthquake hazard which was previously unsuspected and the existing close agreement between observed slip rates on major strike slip faults in turkey and predictions from global plate motion models is spurious whether the cafz is real or based on mistaken interpretations of diverse evidence is thus a matter of some importance the aim of this comment is to describe difficulties which arise over the published interpretation of the cafz with the aim of encouraging either a retraction or a more thorough presentation of the available evidence in support of the existence of a major active fault zone in the required position three main difficulties are discussed in detail first strands of the cafz have been interpreted in many localities where previous detailed studies have either found no evidence of faulting or have reported ancient faults which have been described as no longer active second many other features which previous studies have explained satisfactorily are reinterpreted as consequences of active strike slip faulting finally no observational evidence is presented for the slip rate or the timing of the start of the alleged present phase of slip on the cafz the suggestion that it has slipped by 24 km during this present phase of activity is inadequately documented and conflicts with other evidence

extension on the tibetan plateau recent normal faulting measured by insar and body wave seismology we use insar and body wave modelling to determine the faulting parameters for a series of five mw 5 9 7 1 normal faulting earthquakes that occurred during 2008 including the march 20 yutian earthquake mw 7 1 one of the largest normal faulting events to have occurred recently on the continents we also study three earlier normal faulting earthquakes that occurred in southern tibet between 1992 and 2005 coseismic deformation for each of these eight events is measured with ascending and descending interferograms from envisat ers and alos sar data elastic dislocation modelling of the line of sight insar displacements and body wave seismological modelling of p and sh waves are used to estimate fault parameters and are found to be in good agreement for all the events studied the use of insar to measure deformation allows a relatively precise determination of the fault location in addition to resolving the focal plane ambiguity only five of the eight events are associated with a clear surface topographic feature suggesting that an underestimation of the amount of extension would result from using the surface expressions of normal faulting alone the observations in all cases are consistent with slip on planar surfaces with dips in the range 40 50 that penetrates the uppermost crust to a depth of 10 15 km we find no evidence for active low angle dip less than 30 normal faulting the contribution of the normal faulting to overall extension estimated by summing seismic moments over earthquakes for the past 43 yr is 3 4 mm yr 1 or 15 20 per cent of the rates of extension measured across the plateau using gps 85 per cent of the moment release in normal faulting over the past 43 yr has occurred in regions whose surface height exceeds 5 km this observation adds weight to the suggestions that the widespread normal faulting on the plateau is the result of variations in the gravitational potential energy of the lithosphere

high pressure metasediments in central turkey constraints on the neotethyan closure history 1 the distribution of oceanic domains and continental blocks in central anatolia remains a challenge in understanding the alpine geodynamic evolution of the tethys realm the consumption of a neotethys oceanic branch at the mesozoic cenozoic boundary welded the central anatolian crystalline complex in central turkey and the anatolide tauride block in western turkey with the northerly eurasian margin whether those two regions constituted a single or two distinct continental masses is still matter of debate high pressure metamorphism has been locally evidenced in the afyon zone which was however defined as a greenschist facies metamorphic zone of the anatolide tauride block since the afyon zone composes a metamorphic equivalent of a continental margin exposed far south of the izmir ankara suture zone this encouraged us to reevaluate its metamorphic evolution in order to better understand the relation between western and central turkey our investigations reveal that the high pressure minerals fe mg carpholite and glaucophane are present in the entire afyon zone which we reconsider as a blueschist facies zone we additionally present a tectonic reconstruction stripping off the postcollisional tectonics it reveals that today s bending of the high pressure belt is consistent with an eocene collision of the anatolide tauride block around the southern edge of the central anatolian crystalline complex we argue that the central anatolian crystalline complex and the anatolide tauride block were two distinct continental masses separated by a neotethyan oceanic stripe the closure of which engendered subduction related metamorphism in the latter and arc volcanism and high grade metamorphism in the former by late cretaceous to early cenozoic

effects of plate convergence obliquity on timing and mechanisms of exhumation of a mid crustal terrain the central anatolian crystalline complex abstract apatite fission track ft ages from the central anatolian crystalline complex cacc a microcontinent within the turkish segment of the alpine himalayan orogen vary dramatically from north to south this variation correlates with differences in the obliquity of convergence of the continental fragment relative to the pontide belt for the northern cacc and the tauride belt for the southern cacc the northern cacc was deformed and metamorphosed during late cretaceous orogen normal collision and was exhumed from the mid crust to shallow crustal levels 50 ma to the present in contrast the southern cacc nigde massif was initially deformed and metamorphosed during late cretaceous contraction but subsequently developed as a metamorphic core complex in a wrench dominated regime and was exhumed to

new sedimentological and structural data from the ecemis fault zone southern turkey implications for its timing and offset and the cenozoic tectonic escape of anatolia fig 1 map of the cukurba abg demirkazik area adapted from cetin 2000 fig 6 tcu is the

temporary seismic quiescence se turkey summary the border zone that is the contact of the arabian plate with the three plates of turkey eurasia and iran to the north has been remarkably aseismic during this century by extending the period of observation backwards in time by a few centuries it is shown that this seismicity is atypical of the long term behaviour of the zone and due to a quiescent period in the activity of the area during the 20th century in turn this implies that short term data alone do not provide a reliable assessment of earthquake hazard

quantifying geological structures of the nigde province in central anatolia turkey using srtm dem data a digital terrain model and a 3d fly through model of the nigde province in central anatolia turkey were generated and quantitatively analyzed employing the shuttle radar topographic mission srtm digital elevation model dem besides stream drainage patterns lineaments and structural geological features were extracted and analyzed in the process of analyzing and interpreting the dem for landforms criteria such as color and color tones attributes of heights topography shaded dem and 3d fly through model and stream drainage patterns were employed to acquire geo information about the land such as hydrologic geomorphologic topographic and tectonic structures in this study the srtm dem data of the study region were experimentally used for both dem classification and quantitative analysis of the digital terrain model the results of the dem classification are 1 low plain including the plains of bor and altunhisar 20 7 2 high plain including the misli konakli plain 28 8 3 plateau plain including the melendiz ciftlik plateau plain 1 0 4 mountain including the nigde massif 33 3 and 5 high mountain 16 2 high mountain areas include a caldera complex of mt melendiz mt hasan and mt pozanti apart from the ala mountains called aladaglar and the bolkar mountains called bolkarlar in the study region 7 312km2 analysis of both the stream drainage patterns and the lineaments revealed that the nigde province has a valley zone called karasu valley zone kvz or nigde valley zone nvz where settlements and agricultural plains particularly the bor plain in addition to settlements of the bor town and the central city of nigde have the most flooding risk when a heavy raining occurs the study revealed that the nvz diagonally divides the study region roughly into two equal parts heading from northeast to southwest according to the map created in this study the right side of the nvz has more mountainous area where the aladaglar is a wildlife national park consisting of many species of fauna and flora whereas the left side of the nvz has more agricultural plain with exception of a caldera complex of mt melendiz and volcanic mt hasan the south of the study region includes the bolkarlar in addition the ecemis fault zone efz lying along the ecemis rivulet running from north to south at the west side of the aladaglar forms the most important and sensitive location in the region in terms of the tectonics

neotectonics and long term seismicity in europe and the mediterranean region we present a neotectonic model of ongoing lithosphere deformation and a corresponding estimate of long term shallow seismicity across the africa eurasia plate boundary including the eastern atlantic mediterranean region and continental europe gps and stress data are absent or inadequate for the part of the study area covered by water thus we opt for a dynamic model based on the stress equilibrium equation this approach allows us to estimate the long term behavior of the lithosphere given certain assumptions about its structure and physics for both land and sea areas we first update the existing plate model by adding five quasirigid plates the ionian sea adria northern greece central greece and marmara to constrain the deformation pattern of the study area we use the most recent data sets to estimate the lithospheric structure the models are evaluated in comparison with updated data sets of geodetic velocities and the most compressive horizontal principal stress azimuths we find that the side and basal strengths drive the present day motion of the adria and aegean sea plates whereas lithostatic pressure plays a key role in driving anatolia these findings provide new insights into the neotectonics of the greater mediterranean region finally the preferred model is used to estimate long term shallow seismicity which we retrospectively test against historical seismicity as an alternative to reliance on incomplete geologic data or historical seismic catalogs these neotectonic models help to forecast long term seismicity although requiring additional tuning before seismicity rates are used for seismic hazard purposes

non marine sedimentation associated with oligocene recent exhumation and uplift of the central taurus mountains s turkey abstract three related basins in southern turkey the ecemis basin the karsanti basin and the aktoprak basin document the neogene recent regional exhumation and surface uplift history of the central taurus mountains the regional tectonic framework was established by a late eocene phase of compressional deformation that ended tethys related marine deposition during the oligocene early miocene non marine sedimentation was dominantly from braided rivers flowing from the nascent taurus mountains and from the nigde metamorphic massif further north during this period erosion more or less kept pace with exhumation and the topography remained subdued allowing a marine incursion probably eustatically controlled into the karsanti basin in the east during early oligocene time regional exhumation was possibly controlled by thermal uplift of an actively extending area located behind the subducting s neotethys in the eastern mediterranean sea during exhumation largely ophiolitic rocks were eroded revealing the deformed mesozoic tauride carbonate platform beneath the area was affected by a short lived pulse of compressional deformation transpression probably in mid miocene time but extensional exhumation then resumed as indicated by the presence of metamorphic derived clasts from the adjacent nigde massif late miocene deposition was dominated by large inward draining lakes consistent with regional evidence of a humid climate during this time strong surface uplift took place during plio quaternary time drainage to the mediterranean became established allowing river valleys to incise deeply into the flanks of the taurus mountains palaeo valleys were successively infilled with coarse alluvial sediments this deposition was influenced by ne sw trending extensional faults in addition the sedimentary evolution of the area was strongly influenced by the nne ssw trending ecemis fault zone which has experienced ca 60 km of left lateral strike slip since the late eocene an important pulse of normal faulting transtension in latest miocene early pliocene time generated large fault scarps these acted as sources for large plio quaternary alluvial fans which prograded across active strike slip faults the morphology of these fans was influenced by a combination of quaternary climatic change axial fluvial downcutting and active strike slip tectonics in general the plio quaternary regional uplift of the taurus mountains may relate to underplating of material derived from the african plate during progressive collision with the anatolian eurasian plate in the vicinity of the easternmost mediterranean sea

new views on earthquake faulting in the zagros fold and thrust belt of iran the zagros fold and thrust belt is amongst the world s most seismically active mountain ranges and is influential in our understanding of continental collisions the presence of hormuz salt at the base of the 10 km thick folded sedimentary cover together with the general absence of coseismic surface rupturing have led to an assumption that earthquakes are concentrated within the basement here we reinterpret the seismicity of the zagros in light of insar studies that show some recent earthquakes ruptured the competent group of mechanically strong strata in the lower sedimentary cover local network data demonstrate that microseismicity occurs within the basement reaching depths of 20 km and in places 30 km centroid depths of larger mw 5 earthquakes are mostly 4 14 km with rare events up to 20 km and 28 km along the oman line within the simply folded belt most of these events are contained within the competent group and are limited to mw 6 5 earthquakes occur earthquakes within the competent group can account for much of the overall shortening at this level but the seismic strain rate in the basement is much lower it is unclear whether the basement deforms by aseismic creep or folding beneath the sfb or by ductile shortening beneath the high zagros or iranian plateau

systematic biases in subduction zone hypocenters 1 earthquake hypocenters from global datasets commonly have regional biases in their locations due to the use of a one dimensional velocity model in their location to analyze this effect we group intermediate depth earthquakes into forty four 500 km long sections of subduction zone we relocate earthquakes in each group relative to one another and in a three dimensional global velocity model hypocenters shift up to 25 km regionally when these effects are included most earthquakes in circum pacific subduction zones are pulled toward the pacific location uncertainties from the relative relocations are reduced to one fifth of those from single event locations wadati benioff zone thicknesses are reduced to two thirds of their original thickness these biases alter estimates of depth to slab beneath arc volcanoes up to 50 km and alter measurements such as the volume of mantle wedge available for water storage or melt generation and the size of the thrust zone on which large earthquakes can occur

gps constraints on continental deformation in the africa arabia eurasia continental collision zone and implications for the dynamics of plate interactions 1 the gps derived velocity field 1988 2005 for the zone of interaction of the arabian african nubian somalian and eurasian plates indicates counterclockwise rotation of a broad area of the earth s surface including the arabian plate adjacent parts of the zagros and central iran turkey and the aegean peloponnesus relative to eurasia at rates in the range of 20 30 mm yr this relatively rapid motion occurs within the framework of the slow moving 5 mm yr relative motions eurasian nubian and somalian plates the circulatory pattern of motion increases in rate toward the hellenic trench system we develop an elastic block model to constrain present day plate motions relative euler vectors regional deformation within the interplate zone and slip rates for major faults substantial areas of continental lithosphere within the region of plate interaction show coherent motion with internal deformations below 1 2 mm yr including central and eastern anatolia turkey the southwestern aegean peloponnesus the lesser caucasus and central iran geodetic slip rates for major block bounding structures are mostly comparable to geologic rates estimated for the most recent geological period 3 5 myr we find that the convergence of arabia with eurasia is accommodated in large part by lateral transport within the interior part of the collision zone and lithospheric shortening along the caucasus and zagros mountain belts around the periphery of the collision zone in addition we find that the principal boundary between the westerly moving anatolian plate and arabia east anatolian fault is presently characterized by pure left lateral strike slip with no fault normal convergence this implies that extrusion is not presently inducing westward motion of anatolia on the basis of the observed kinematics we hypothesize that deformation in the africa arabia eurasia collision zone is driven in large part by rollback of the subducting african lithosphere beneath the hellenic and cyprus trenches aided by slab pull on the southeastern side of the subducting arabian plate along the makran subduction zone we further suggest that the separation of arabia from africa is a response to plate motions induced by active subduction

tectonic stress state in ne japan as part of the okhotsk plate abstract an existing geodetic flow velocity model obtained by using an internal free network adjustment technique is used to derive estimates for various strain rates parameters in ne japan the greatest shortening rates of the principal strains trending e w are located in regions where much steady internal frame invariant plastic flow deformation is observed to be taking place the internal geodetic adjustment technique yielded the internal deformation in the tohoku arc most of the intraplate deformations including the much folding deformations observed in the inner zone are produced from within an interseismic transient elastic loading at a strongly coupled locked japan trench would not be needed the observed ongoing extensive ductile folding deformation in the inner zone of tohoku may mean that the geodetic strain rates causing shortening at 2 3 cm yr probably reflect the more correct level of the deformation which is steady permanent in ne japan as compared with seismic faulting data which indicate 0 5 cm yr shortening the calculated principal strain rates are used to make an interpretation for the origin of the deviatoric principal stresses within the greater regional plate tectonic framework the tectonic stress state in ne japan as part of the okhotsk plate could mostly be influenced by the okhotsk plate which is extruding southward to lessen the significant accumulated contractional deformation in ne asia in the verkhoyansk cherskii mountains the principal strain rates are n s extensional essentially everywhere in ne japan as a result of the southerly extrusion except in its southernmost leading edge in the uetsu fossa magna province where the japan alps rampart rises in front of the extrusion here an e w compressional stress state prevails a second e w contractional zone is found in north central tohoku extending from the sanriku province in the outer zone to the inner zone in the japan sea side being more prevalent in the latter zone the calculated rotation rates from the geodetic flow model are clockwise cw in both of the e w contractional regions ne japan extruding southward faces buttresses in 1 the oga ojika line ool and or a crustal weakness zone between the northern and the southern halves of tohoku approx at 38 5 n latitude and especially 2 the japanese alps rampart these obstacles cause the northern and southernmost tohoku to veer to its right and rotate cw thereby setting up the e w trending compressional deformation in their respective inner zones between the ool or the 38 5 n boundary and the kanto tectonic line ktl the sense of the differential rotations is counterclockwise ccw towards the ocean to the se the northern tohoku north of the ool and the southernmost tohoku south of the ktl cannot rotate ccw towards the ocean because of the izu block s collision in the south and the relatively strong coupling along the subduction interface beneath the japan trench in the north off sanriku the relatively stronger long term coupling between the northern tohoku and the pacific plate at the sanriku coast with respect to that in off fukushima is due to a flatter subduction of the pacific slab there increasing the plates interface contact area the flattening of the subduction dip angle was caused by ccw rotation and shifting of the northern tohoku along the dextral honjo matsushima line roughly corresponding to the ool towards the pacific and overriding of the subduction zone during the formation of the japan sea

active accommodation of plate convergence in southern iran earthquake locations triggered aseismic slip and regional strain rates 1 we present a catalog of interferometric synthetic aperture radar insar constraints on deformation that occurred during earthquake sequences in southern iran between 1992 and 2011 and explore the implications on the accommodation of large scale continental convergence between saudi arabia and eurasia within the zagros mountains the zagros mountains a salt laden fold and thrust belt involving 10 km of sedimentary rocks overlying precambrian basement rocks have formed as a result of ongoing continental collision since 10 20 ma that is currently occurring at a rate of 3 cm yr we first demonstrate that there is a biased misfit in earthquake locations in global catalogs that likely results from neglect of 3 d velocity structure previous work involving two m 6 earthquakes with well recorded aftershocks has shown that the deformation observed with insar may represent triggered slip on faults much shallower than the primary earthquake which likely occurred within the basement rocks 10 km depth we explore the hypothesis that most of the deformation observed with insar spanning earthquake sequences is also due to shallow triggered slip above a deeper earthquake effectively doubling the moment release for each event we quantify the effects that this extra moment release would have on the discrepancy between seismically and geodetically constrained moment rates in the region finding that even with the extra triggered fault slip significant aseismic deformation during the interseismic period is necessary to fully explain the convergence between eurasia and saudi arabia