relocation and assessment of seismicity in the iran region summary more than 2000 instrumentally recorded earthquakes occurring in the iran region during the period 1918 2004 have been relocated and reassessed with special attention to focal depth using an advanced technique for 1 d earthquake location a careful review of starting depths association of teleseismic depth phases and the effects of reading errors on these phases are made and when necessary waveforms have been examined to better constrain ehb focal depths uncertainties in ehb epicentres are on the order of 10 15 km in the iran region owing to the earth s lateral heterogeneity and uneven station distribution uncertainties of reviewed ehb focal depth estimates are on the order of 10 km as compared to about 4 km for long period p and sh body waveform inversions nevertheless these ehb depth estimates are sufficiently accurate to resolve robust differences in focal depth distribution throughout the iran region and within their errors show patterns that are in agreement with the smaller number of earthquakes whose depths have been confirmed by body wave modelling or local seismic networks the importance of this result is that future earthquakes with apparently anomalous depths can easily be identified and checked if necessary most earthquakes in the iranian continental lithosphere occur in the upper crust with the crustal shortening produced by continental collision accommodated entirely by thickening and distributed deformation in the zagros mountains nearly all earthquakes are confined to the upper crust depths 20 km and there is no evidence for a seismically active subducted slab dipping ne beneath central iran by contrast in southeastern iran where the arabian seafloor is being subducted beneath the makran coast low level earthquake activity occurs in the upper crust as well as to depths of at least 150 km within a northward dipping subducting slab near the oman line a region transitional between the zagros and the makran seismicity extends to depths of up to 30 45 km in the crust consistent with low angle thrusting of arabian basement beneath central iran in north central iran along the alborz mountain belt seismic activity occurs primarily in the upper crust but with some infrequent events in the lower crust particularly in the western part of the belt the talesh where the south caspian basin underthrusts nw iran earthquakes that occur in a band across the central caspian following the apscheron balkhan sill between azerbaijan and turkmenistan have depths in the range 30 100 km deepening northwards these are thought to be connected with either incipient or remnant northeast subduction of the south caspian basin basement beneath the east west trending apscheron balkhan sill curiously in this region of genuine mantle seismicity there is no evidence for earthquakes shallower than 30 km

empirical observations regarding reverse earthquakes blind thrust faults and quaternary deformation are blind thrust faults truly blind active thrust faults pose a significant seismic hazard worldwide many of these faults include blind thrusts where the propagating fault tip does not reach the earth s surface and buried faults where the geomorphic expression of the fault is obscured by subsequent sedimentation and or erosion this raises the issue of whether conventional geologic geomorphic and paleoseismic methods can be used to identify and characterize thrust faults for the assessment of seismic hazards or whether these faults sometimes are truly blind we compiled a data base of 148 worldwide moderate to large magnitude thrust reverse earthquakes to evaluate whether or not the event occurred on a fault that could have been identified prior to the earthquake on the basis of recognizable quaternary surface deformation i e a pre existing fault or fold analysis of the data shows that interplate reverse earthquakes almost always are associated with pre existing quaternary deformation that was or could have been recognized prior to the earthquake in particular most interplate reverse earthquakes are associated with an active reverse fault at the surface and or an active anticline in contrast intraplate reverse earthquakes seldom occur on faults associated with pre existing recognizable surface deformation we conclude that thrust faults can be detected in interplate regions with careful quaternary geologic and geomorphic mapping furthermore the absence of quaternary surface deformation can be used to infer the absence of an underlying active blind thrust fault in interplate tectonic settings however the data show that quaternary geologic mapping techniques alone likely are insufficient to characterize blind thrusts in intraplate regions in these areas inclusion of a floating or random earthquake may be necessary to assess earthquake hazards

active faults in the zagros and central iran abstract active tectonic movements in the northwestern zagros include right lateral slip at the rate of about 10 mm a along the main recent fault which inherits the position of the main thrust now inactive and active thrusting and accompanying folding distributed between several zones southwest of the main recent fault in the southeastern zagros the fars province there are several right lateral faults that extend n s obliquely to the overall trend of the zagros fault and fold belt these may be either branches of the main recent fault or faults accommodating relative broadening of the outer zagros in its southeastern segment the main thrust in the southeastern zagros also remains inactive the ipak north tehran and mosha fault zones and several minor structures in the eastern alborz form the e w trending active fault system with combined reverse and left lateral slip on the ipak and mosha zones lateral movements with the late quaternary mean rate exceeding 1 mm a dominate over vertical fault movements together with right lateral faults stretching northeast of zagros the faults of the alborz may accommodate east directed motion of the iranian microplate

palaeoseismicity and pottery investigating earthquake and archaeological chronologies on the hajiarab alluvial fan iran for millennia humans have lived in locations that are highly vulnerable to large earthquakes often out of strategic or cultural necessity and or the proximity of these locations to resources necessary for survival despite the often catastrophic effects when large earthquakes occur recent history reveals that human nature is to rebuild rather than relocate implying that seismic activity is not a sufficient deterrent of population growth in tectonically vulnerable areas in order to investigate whether this was the case for ancient civilisations and thus perhaps a fundamental tenet of human behaviour a palaeo earthquake history was developed for the active cheskin and ipak faults in northwestern iran and compared with the well resolved archaeological history of the nearby sagzabad cluster settlements of zagheh 7170 6300 bp ghabristan 6215 4950 bp and sagzabad 4050 2350 bp combining new geologic geomorphic and chronologic datasets revealed the presence of a fault propagated anticline formed by large mw 6 5 7 0 earthquakes on a blind thrust fault that projects to seismogenic depth directly beneath the sagzabad cluster settlement sites large earthquakes with a return period of 90 probability under most faulting scenarios that the energy release from these earthquakes would have been of sufficient magnitude to generate peak horizontal acceleration pha values at the sagzabad cluster in excess of likely threshold values for complete settlement destruction poisson modelling assuming a time displacement repeating model for earthquake recurrence indicates a 66 42 probability of one two earthquakes that would generate pha 0 25 g occurring during occupation of zagheh a 79 55 probability for ghabristan and an 88 65 probability for sagzabad despite the near certainty that the residents of these holocene settlements experienced large destructive earthquakes the near continuous history of occupation at this area suggests that early humans were not apt to relocate in response to earthquake activity environmental e g alluviation stream channel avulsion climate change cultural and or political factors may have been more important drivers of settlement shifts and abandonment at the sagzabad cluster of iran

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

ephemeral stream response to growing folds the response of ephemeral alluvial streams to active tectonics is not as well established as those documented for perennial alluvial streams this study documents the response of ephemeral streams transverse to growing folds along the north fl ank of the san bernardino mountains in southern california the growing folds emerge amid a broad sloping piedmont mantled by north dipping alluvial fans and underlain by coarse angular gravel and sand of mixed provenance the study area contains fans composed of two distinct lithologies that control the expression of the folds sediment transport processes differ among alluvial perennial and ephemeral channels and play a primary role in defi ning the range of responses that ephemeral streams have to an actively rising fold we fi nd that ephemeral streams respond by 1 changing pattern from a single slightly incised channel with well defi ned banks to a braided channel upstream of the fold axis 2 incising across the fold axis preserving a terrace and braid bars and 3 returning to a single thread less incised channel downstream of the fold axis this channel response is documented for both a topographically obvious anticlinal fold the cougar buttes anticline as well as a suspected but not topographically obvious anticline the pitzer buttes anticline variations from this general model appear to be correlated with locations of slow fold growth and or channel alluvium that is fi ne grained and of low cohesion a growing fold such as the cougar buttes anticline provides a laboratory for the investigation of the development of transverse streams with respect to position along strike with the fold axis some streams crossing the cougar buttes anticline are antecedent whereas others are consequent to the growth of the fold these observations lay the foundation for a conceptual model for ephemeral stream response to active tectonics particularly useful in identifying previously unrecognized actively rising folds in this study the fold axis of the cougar buttes anticline is revealed to extend at least 1 km beyond its current obvious topographic expression because ephemeral streams are sensitive to tectonic deformation they can be used locally in paleoseismological investigations regionally to understand the strain partitioning between the big bear and mojave blocks and conceptually to constrain geodynamic models investigating the interaction between surface processes and the geometry of and slip rates on faults responsible for fold growth

implications of earthquake focal mechanism data for the active tectonics of the south caspian basin and surrounding regions summary the south caspian basin is a relatively aseismic block within the alpine himalayan belt but is surrounded by zones of high seismicity we used the focal mechanisms of 16 earthquakes whose source parameters we determined from inversion of body waves and the mechanisms of 15 other earthquakes to determine the style of faulting in the seismic belts surrounding the south caspian basin earthquakes beneath the talesh mountains of north west iran and immediately off shore in the south west caspian sea have shallow thrust mechanisms showing that the continental crust of north west iran is overthrusting the oceanic like crust of the south caspian basin earthquakes south of the caspian sea in northern iran show a mixture of focal mechanisms both high angle reverse faulting and left lateral strike slip faulting mechanisms are observed in the high alborz mountains farther south on the edge of the central iran plateau oblique left lateral reverse mechanisms are observed it appears that the ne direction of shortening between central iran and the south caspian basin is partitioned into pure left lateral strike slip and thrusting in the wnw trending high alborz but is accommodated by oblique faulting in lower elevations earthquakes in the kopet dag mountains east of the caspian sea also show a mixture of high angle reverse and strike slip faulting mechanisms and may be another example of the partitioning of oblique slip into strike slip and thrust motion normal faulting mechanisms at centroid depths of 35 50 km dominate in the belt of seismicity that extends across the central caspian sea the significance of the normal faulting earthquakes is enigmatic it is improbable that these events represent the motion between the southern caspian basin and eurasia for they imply a sense of motion that is incompatible with the observed topography and folding in the sediments two shallow earthquakes at about 12 km depth in this belt one a small event and the other a large second subevent of a multiple earthquake have thrusting mechanisms suggesting that shortening occurs as the continental crust of the northern caspian sea is thrust over the oceanic like crust of the southern caspian basin shortening is also suggested by the orientations of folds in the sedimentary cover south of the central caspian sea seismic belt we suggest that this shortening does indeed represent a nne motion of the caspian sea relative to eurasia but that the motion is slow and has not produced many earthquakes the deeper normal faulting events may be related to bending or down dip extension of the incipient subducted slab if the motion of the caspian sea relative to eurasia is indeed slow then the motion in the alborz between central iran and the south caspian basin will be almost the same as that between iran and eurasia as has previously been assumed the combined effect of the overthrusting of the south caspian basin by the talesh alborz mountains in the south and by the continental crust of the northern caspian sea in the north will lead to the eventual destruction of the south caspian basin and the possible formation of an intermediate depth dipping seismic zone within the continental interior similar to that presently observed in the hindu kush

the bam iran earthquake of december 26 2003 from an engineering and seismological point of view abstract this paper is devoted to studying the destructive bam earthquake from an engineering seismological point of view on december 26 2003 a large earthquake of magnitude 6 7 m s shook the bam district located in southeastern iran about 80 of buildings totally collapsed several dozen villages were destroyed and tens of them were severely damaged more than 45 000 people were killed and 30 000 were injured according to the macroseismic data focal depth of the event was estimated at 7 2 km the event was associated with a 9 km surface rupture of the bam fault the maximum residual strike slip displacement is 5 cm which is left lateral the highest recorded peak ground acceleration is at bam station 0 98 g vertical and 0 87 g horizontal located about 1 5 km from the surface rupture the macroseismic analyses show that the epicenter of the quake is 1 5 km east of bam all of the masonry buildings totally collapsed in the epicentral area many semi engineered structures were heavily damaged and some of them collapsed engineered structures constructed according to the seismic code of iran have shown very good structural behavior without significant damage finally the earthquake intensity at the epicenter is determined as ix on the msk scale which strongly decreases with distance from the surface ruptures

faulting and folding in quaternary deposits of tehran s piedmont iran abstract tehran lies on the southern flank of the central alborz an active mountain belt characterized by many historical earthquakes some of which have affected tehran itself the border between the alborz mountain and the tehran s piedmont northern part of tehran city is marked by the north tehran fault ntf dividing the eocene rock formation from the alluvial units of different ages early pleistocene to the recent alluvium a detail mapping of the piedmont combined with structural study reveal that two active thrust faults situated south of the ntf are of importance for hazard assessment of the city the geomorphological evidences along the ntf are not in agreement with an active fault indicating that the fault activity may have been shifted southward furthermore differentiation of newly recognized alluvial units and their inferred ages together with the mapped fault pattern permit us to characterize the quaternary deformation the late pleistocene alluvial deposits consist of three alluvial fans among them the youngest one together with the modern alluvial fan defines the holocene deposit the present deformation in the piedmont is accommodated along vertically left lateral strike slip faults and low angle thrust faults trending in range from n070 to n110e

simulated impacts of a mesoscale convective system on the track of typhoon robyn during tcm 93 abstract the contribution that a mesoscale convective vortex that developed within the circulation of typhoon robyn 1993 may have had to a significant tropical cyclone track change is simulated with a mesoscale model using initial conditions that approximate the circulations measured by aircraft during the tropical cyclone motion tcm 93 field experiment a dry version of the psu ncar mesoscale model is used to first investigate the dynamic aspects of the interaction a deceleration of about 2 m s 1 and then more northward movement similar to that observed for typhoon robyn could have been produced by an interaction with the mesoscale convective vortex of the type modeled in the control run sensitivity of the simulated track change is tested for various aspects of the mesoscale vortex and tropical cyclone it is found that track deflections between 67 and 130 km in 18 24 h could be produced under a variety of realistic scenarios as the mesoscale vortex is advected around the tropical cyclone by the

interactions between the greenland ice sheet and the liverpool land coastal ice cap during the last two glaciation cycles the sedimentary record from the ugleelv valley on central jameson land east greenland adds new information about terrestrial palaeoenvironments and glaciations to the glacial history of the scoresby sund fjord area a western extension of a coastal ice cap on liverpool land reached eastern jameson land during the early scoresby sund glaciation approximate to the saalian during the following glacial maximum the greenland ice sheet inundated the jameson land plateau from the west the weichselian also starts with an early phase of glacial advance from the liverpool land ice cap while polar desert and ice free conditions characterised the subsequent part of the weichselian on the jameson land plateau the two glaciation cycles show a repeated pattern of interaction between the greenland ice sheet in the west and an ice cap on liverpool land in the east each cycle starts with extensive glacier growth in the coastal mountains followed by a decline of the coastal glaciation a change to cold and arid climate and a late stage of maximum extent of the greenland ice sheet less

holocene slip rate on the sabzevar thrust fault ne iran determined using optically stimulated luminescence osl abstract fault slip rates and the recurrence interval between earthquakes can be determined from reliable dating of deformed sediments we report optically stimulated luminescence osl ages of alluvial gravels fine grained sediments and colluvial deposits associated with the sabzevar thrust fault in northeastern iran six samples of the late quaternary deposits were dated by osl using the single aliquot regenerative dose sar protocol the osl ages indicate deposition of alluvial gravels in the study region between 30 and 9 13 ka followed by a period of fluvial incision which is ongoing at the present day the alluvial deposits have been uplifted by 9 5 m relative to the river level indicating a holocene slip rate of 1 mm yr and a rate of convergence across the fault of 0 4 0 6 mm yr assuming a maximum fault dip of 60 the average interval between large earthquakes on the sabzevar fault will be 3000 years if the fault dips 60 and less if the fault dip is less the last earthquake to destroy sabzevar was in 1052 a d

tropical cyclone track prediction with a barotropic spectral model abstract a barotropic spectral model bsm is developed to investigate the possibility of forecasting tropical cyclone tracks with global general circulation models the model is governed by a barotropic vorticity equation in spherical coordinates which is solved wing a spectral method with spherical harmonic basis functions the model was run with a triangular truncation of 128 on half of the northern hemisphere 180 w 0 w and was initialized using horizontal winds from the nmc analyses vertically averaged from 1000 to 100 mb the storm circulation is represented by a specified axisymmetric vortex and the model was tested by making 30 track forecasts of atlantic tropical cyclones 13 storms which occurred from 1979 to 1984 the skill of the model was assessed by comparing the track forecasts to forecasts from a model based on climatology and persistence cliper the bsm has statistically significant skill for 24 and 36 h track forecasts and longer range of skill for forecasts of low latitude storms

patterns of historical earthquake rupture in the iranian plateau the iranian plateau accommodates the 35 mrn yr convergence rate be tween the eurasian and arabian plates by strike slip and reverse faults with relatively low slip rates in a zone 1000 km across although these faults have only locally been the subject of paleoseismological studies a rich historical and archeological record spans several thousand years long enough to establish recurrence intervals of 1000 to 5000 yr on individual fault segments several clusters of earthquakes provide evidence of interaction among reverse and strike slip faults probably due to adjacent faults being loaded by individual earthquakes the dasht e bayaz sequence of 1936 to 1997 includes earthquakes on left lateral right lateral and reverse faults the neyshabur sequence of four earthquakes between 1209 and 1405 respected the seg ment boundary between the neyshabur and binalud reverse fault systems the two pairs of earthquakes may have ruptured different faults in each segment similar to the 1971 and 1994 san fernando california earthquakes the 1978 tabas reverse fault earthquake was preceded by the 1968 ferdows earthquake part of the dasht e bayaz sequence the north tabriz fault system ruptured from southeast to north west in three earthquakes from 1721 to 1786 a previous cluster may have struck this region in 855 to 958 the mosha fault north of tehran ruptured in three earthquakes in 958 1665 and 1830 five large earthquakes struck the tehran region from 743 to 1177 but only two that large have struck the area since 1177 other earthquakes occurred in pairs in the talesh mountains near the caspian sea 1863 1896 the iran turkey border 1840 1843 and the nayband gowk fault system both 1981 other historical events did not occur as parts of sequences the historic seismic moment release in iran accounts for only a small part of the plate convergence rate which may be due to aseismic slip or to the iranian historical record long as it is being too short to sample long term deformation across the plateau no historic earthquakes of m 8 have struck iran however several long straight strike slip faults doruneh west neh east neh and nayband have not sustained large historical earthquakes raising the possibility that these long faults could produce earthquakes of m 8 thereby removing at least part of the apparent slip deficit an increased understanding of iran s seismic hazard could be obtained by an extensive paleoseismology program and space geodetic arrays supplementing the abundant historical and archaeological record

a re assessment of focal depth distributions in southern iran the tien shan and northern india do earthquakes really occur in the continental mantle summary we investigate the depth distribution of earthquakes within the continental lithosphere of southern iran the tien shan and northern india by using synthetic seismograms to analyse p and sh body waveforms in the zagros mountains of southern iran earthquakes are apparently restricted to the upper crust depths of 20 km whereas in the tien shan and northern india they occur throughout the thickness of the continental crust to depths of 40 45 km we find no convincing evidence for earthquakes in the continental mantle of these regions in spite of previous suggestions to the contrary and question whether seismicity in the continental mantle is important in any part of the world in some regions such as iran the aegean tibet and california seismicity is virtually restricted to the upper continental crust whereas in others including parts of east africa the tien shan and northern india the lower crust is also seismically active although usually less so than the upper crust such variations cannot reliably be demonstrated from published catalogue or bulletin locations even from ones in which depth resolution is generally improved in contrast to the oceanic mantle lithosphere in which earthquakes certainly occur the continental mantle lithosphere is we suggest virtually aseismic and may not be significantly stronger than the lower continental crust these variations in continental seismogenic thickness are broadly correlated with variations in effective elastic thickness suggesting that the strength of the continental lithosphere resides in the crust and require some modification to prevalent views of lithosphere rheology

long term fault slip rates distributed deformation rates and forecast of seismicity in the iranian plateau in this paper the long term crustal flow of the iranian plateau is computed using a kinematic finite element model neokinema software based on the iterated weighted least squares method the models are fitted to the newest data set of iran including updated fault traces geologic fault offset rates geodetic benchmark velocities principal stress directions and velocity boundary conditions we are successful to find the best kinematic model in which geological slip rates geodetic velocities and interpolated stress directions are fitted at levels of 0 35 1 0 and 1 0 datum standard deviation respectively the best fitted model for the first time provides long term fault slip rates velocity and anelastic strain rate field in the iranian plateau from all available kinematic data in order to verify the model the estimates of fault slip rates are compared to slip rates from merely analyzing geodetic benchmark velocities or paleoseismological studies or published geological rates which have not been used in the model our estimated rates are all in the range of geodetic rates and are even more consistent with geological rates than previous gps based estimates using the selected model long term average seismicity maps and long term moment rates are produced on the basis of the shift hypothesis and previous global calibrations our kinematic model also provides a new constraint on ratio of seismic deformation to total deformation for different seismic zones of iran the resulting slip rates and the proposed seismic fraction of deformation provide the necessary input data for future time dependent hazard studies in iran moreover spatial distribution and total number of strong m 6 and major m 7 earthquakes which dominate the seismic hazard are all compatible with the regional seismic catalog

response of alluvial rivers to slow active tectonic movement alluvial rivers respond to valley slope deformation caused by active tectonics in various ways depending on the rate and amount of surficial deformation and on the type of river on the basis of experimental results and field examples hypothetical models of river response to anticlinal uplift and synclinal subsidence were developed for different types of alluvial rivers an experimental braided channel responded to anticlinal uplift across the channel with degradation and terrace formation in the central part of the uplift with subsidence aggradation in the central reach was the main response transverse bars developed downstream of the subsidence axis an experimental meandering channel responded to slope steepening with a sinuosity increase bank erosion and point bar growth occurred downstream of the anticlinal axis and upstream of the synclinal axis upstream of the uplift axis and downstream of the subsidence axis where the slope was flattened water flooded over bars local convexity in longitudinal profiles of the middle rio grande new mexico is considered to be formed by a domal uplift local aggradation and degradation could be explained by the effect of uplift the san joaquin river california which is now highly controlled does not show clear adjustment to the rapid subsidence due to ground water withdrawal it shows however a channel pattern adjustment to active tectonic subsidence that has been occurring for a long time the san antonio and guadalupe rivers in texas both increase their sinuosity significantly where monoclinal movements steepen valley slopes

contribution of archaeological data to studies of earthquake history in the iranian plateau we use archaeological evidence to identify ancient earthquakes in the vicinity of large 20th century events in the iranian plateau two large earthquakes on the zagros main recent fault were preceded by historical earthquakes in ad 1008 and ad 1107 and by earthquakes in the intervals ad 224 459 and 1650 1600 bc giving return times of 1800 2100 500 800 and 850 950 years the ad 1962 ms 7 2 bo in zahra earthquake on the ipak fault in north central iran was preceded by an earthquake in 2000 1500 bc recorded at the sagzabad mound a return time of 3500 4000 years if there are no missing events the ad 1990 ms 7 3 rudbar tarom earthquake in the western alborz mountains was preceded by an earthquake in 1000 800 bc recorded at the marlik mound a return time of 2800 3000 years the ad 1948 ms 7 2 kopeh dagh earthquake that destroyed ashkabad capital of turkmenistan was preceded by an earthquake in 10 bc ad 10 recorded at mithradatkert nesa mound and by an earthquake in 2000 bc recorded at ak tapeh mound assuming no missing earthquakes this region has an earthquake return time of about 2000 years in khorasan province which was struck by a sequence of large earthquakes from ad 1936 to 1997 a mosque at qa en was destroyed in the mid 11th century ad probably the historical earthquake of ad1066 in the absence of palaeoseismic investigations archaeology offers the promise of recording earthquakes through more than one seismic cycle in different regions of iran q 2001 elsevier science ltd all rights reserved

holocene settlement shifts and palaeoenvironments on the central iranian plateau investigating linked systems for thousands of years humans have inhabited locations that are highly vulnerable to the impacts of climate change earthquakes and floods in order to investigate the extent to which holocene environmental changes may have impacted on cultural evolution we present new geologic geomorphic and chronologic data from the qazvin plain in northwest iran that provides a backdrop of natural environmental changes for the simultaneous cultural dynamics observed on the central iranian plateau well resolved archaeological data from the neighbouring settlements of zagheh 7170 6300 yr bp ghabristan 6215 4950 yr bp and sagzabad 4050 2350 yr bp indicate that holocene occupation of the hajiarab alluvial fan was interrupted by a 900 year settlement hiatus multi proxy climate data from nearby lakes in northwest iran suggest a transition from arid early holocene conditions to more humid middle holocene conditions from ca 7550 6750 yr bp coinciding with the settlement of zagheh and a peak in aridity at ca 4550 yr bp during the settlement hiatus palaeoseismic investigations indicate that large active fault systems in close proximity to the tell sites incurred a series of large mw 7 1 earthquakes with return periods of 500 1000 years during human occupation of the tells mapping and optically stimulated luminescence osl chronology of the alluvial sequences reveals changes in depositional style from coarse grained unconfined sheet flow deposits to proximal channel flow and distally prograding alluvial deposits sometime after ca 8830 yr bp possibly reflecting an increase in moisture following the early holocene arid phase the coincidence of major climate changes earthquake activity and varying sedimentation styles with changing patterns of human occupation on the hajiarab fan indicate links between environmental and anthropogenic systems however temporal coincidence does not necessitate a fundamental causative dependency

archaeological sediments from settlement mounds of the sagzabad cluster central iran human induced deposition on an arid alluvial plain abstract we outline results of a pilot geoarchaeological study of three settlement mounds tepe in the qazvin plain near tehran ca 7350 to 2450 cal bp conducted as part of a wider investigation of the interaction between prehistoric human communities and their environments in western iran the aim of the geoarchaeological study was to assess the potential of settlement sediments as records of past human practices and to guide future systematic sampling for geoarchaeological analyses here we integrate bulk sediment sediment texture organic matter with thin section based thin section micromorphology sem analyses in order to characterize human inputs in settlement deposits and infer human practices that drove sediment deposition plinth degradation and various kinds of burning byproducts and domestic and manufacturing waste furnished distinctive inputs to settlement sediments different types of fuel wood perhaps tamarix straw dung may reflect diverse domestic and manufacturing contexts of fire use

the 2002 june 22 changureh avaj earthquake in qazvin province northwest iran epicentral relocation source parameters surface deformation and geomorphology summary the m w 6 4 changureh avaj earthquake occurred on 2002 june 22 in qazvin province northwest iran we use observations from seismology field investigation and analysis of satellite imagery and digital topography to suggest that slip on a previously unrecognized thrust fault herein named the abdarreh fault was responsible for the earthquake inversion of longperiod p and sh body wave seismograms shows rupture on a thrust fault dipping 49 to the southwest and with a centroid depth of 10 km multiple event relocation of the main shock and aftershock epicentres and discontinuous surface ruptures observed after the earthquake are compatible with a northwest propagating rupture on a southwest dipping thrust but maximum recorded displacements are much less than expected from seismology suggesting that much of the slip failed to reach the surface and was accommodated as folding at the surface instead long term folding is difficult to see in the topography of the epicentral region as the abdarreh fold is growing through a relict neogene topography anticlinal uplift can however be inferred from drainage disruption and stream incision the 2002 june 22 changureh earthquake shows the importance of being able to interpret diagnostic features of active faulting in the landscape