the 1986 kalamata south peloponnesus earthquake detailed study of a normal fault evidences for east west extension in the hellenic arc tectonic and seismological data collected in the field following the september 13 1986 kalamata earthquake south peloponnesus are presented and analyzed to discuss the earthquake rupture process and the regional tectonics the event occurred on the kalamata normal fault whose trace was mapped with spot images and topographic and field observations this fault is part of an approximately nnw sse en echelon system cutting through the hellenic nappes the fault striking n15 e on the average with a dip of about 50 has a minimum cumulated quaternary throw of the order of 1 km the measured coseismic slip is 6 18 cm over a length of 6 km the main shock focal mechanism obtained from long period waveform modeling strike 201 10 20 dip 45 5 rake 283 10 25 represents almost pure east west extension and is in good agreement with tectonic observations the centroid depth is constrained to 5 3 km and the seismic moment to 7 0 2 5 1017 n m over 700 aftershocks located by a 16 station network installed after the earthquake for a period of 2 weeks define two clusters separated by a gap of aftershock activity from the surface to a depth of about 10 km the main cluster to the south defines a 45 west dipping plane which lies on the downward extension of the fault mapped at the surface focal mechanisms of aftershocks on this fault plane are homogeneous and represent e w extension as the main shock in contrast the majority of focal mechanisms in the uppermost part of the foot wall show more or less e w compression probably corresponding to postseismic stress release the northern cluster of aftershocks is very dense and located away from the surface rupture within a relay zone between the kalamata and the next en echelon faults to the nw the thouria faults there focal mechanisms represent extension from about n115 to n70 and n20 corresponding mostly to fault reactivation in an area where nonrigid deformations prevail the main shock probably initiated in this relay zone 3 4 s before the rupture front reached the main fault plane and released most of the energy there the rupture presumably propagating southward the focal mechanism of the kalamata earthquake and that of the april 27 1965 earthquake located to the northwest of crete as well as the regional active normal fault pattern imply that e w extension oblique to the hellenic arc is presently the dominant tectonic regime e w stretching occurs partly on reactivated nw se faults parallel to the hellenic structures but mostly on newly formed n s normal faults across those structures the latter faults are responsible for the apparent segmentation of the hellenic belt from southern peloponnesus to crete the existence of active e w extension in this region implies a recent change in the tectonic regime and consequently a change in boundary conditions at the subduction zone probably in response to the incoming margin of africa

tracking earthquake archaeological evidence in late minoan iiib 1300 1200 b c crete greece a proof of concept late minoan lm iiib 1300 1200 b c represents a crucial period in the history of bronze age crete heralding the transition to the iron age through a wave of site destruction and abandonment according to the traditional view earthquakes may have played a significant role in these events a new archaeoseismological approach is proposed to test this hypothesis and to attribute destruction and abandonment to earthquakes potential earthquake archaeological effects peaes are defined and documented at lm iiib sites synchronisms of peaes between sites are based on ceramic evidence the reliability of the peaes is furthermore assessed using empirical ground motion relationships defined for three types of earthquake mechanisms that can be considered to occur in the seismotectonic context of crete 1 normal faulting earthquakes located within the overriding aegean lithosphere 2 earthquakes located on the subduction interface or on splay faults merging with the interface at depth 3 earthquakes within the subducting african lithosphere in the case of lm iiib1 early malia and sissi northeastern crete this proof of concept is successfully applied and supports the hypothesis that seismic shaking is likely to be responsible for the peaes observed a 12 october 1856 a d type earthquake located within the subducting african plate is suggested as the most likely earthquake mechanism in other lm iiib archaeological contexts no convincing evidence for earthquake effects could be identified the hypothesis of a seismic storm causing the demise of minoan crete is not supported by our analysis of archaeological evidence

monitoring subsidence at messara basin using radar interferometry the messara valley is the largest and most productive region in the island of crete greece over the last 20 years extensive exploitation of the aquifer mainly for agricultural purposes has led to a 40 m decrease in the level of groundwater this investigation aims at mapping ground subsidence that might be induced by such overpumping of groundwater using conventional differential interferometry a total of 29 ers 1 and 2 sar and 7 alos palsar images have been used for forming interferograms the images used cover the period from 1992 to 2000 and 2007 to 2010 respectively processing of alos l band data 23 6 cm has revealed a ground motion away from the line of sight of the satellite los direction that amounts to at least 3 cm year for the period 2007 2010 piezometric measurements and other geological parameters have also been analyzed

european mediterranean regional centroid moment tensors 1997 2000 the mediterranean region is seismically very active and undergoing rapid deformation earthquakes as strong as m 6 are present but relatively rare on the other hand moderate magnitude seismicity 4 5 m 5 5 is widespread and often damaging an improved knowedge of moderate magnitude earthquakes can contribute significantly to a better understanding of active tectonics in the region harvard centroid moment tensors cmt today represent the most widely used reference for reliable source mechanisms but modelling seismic sources with the cmt technique for earthquakes with magnitude less than m 5 5 5 is quite difficult since 1997 we are using an extension of the standard cmt algorithm to compute regional centroid moment tensors rcmt for moderate magnitude earthquakes mw as low as 4 0 analyzing intermediate period surface waves from regional and teleseismic seismograms we routinely apply the algorithm to european mediterranean seismicity to produce a catalog of seismic moment tensors for events with magnitude between 4 5 and 5 5 which generally are not included in the harvard cmt catalog in this paper we show the results for earthquakes that occurred between 1997 and 2000 consisting of 252 solutions and we discuss the characteristics of the catalog and the areas where these new data are most relevant

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

post glacial slip history of the sparta fault greece determined by 36cl cosmogenic dating evidence for non periodic earthquakes 1 using 36cl cosmic ray exposure dating we obtained continuous exposure histories for 7 12 m high limestone surfaces at two sites 10 km apart on the sparta normal fault scarp as each major earthquake adds new surface to the cumulative scarp exposing new material to cosmic ray bombardment these exposure histories allow the slip history to be constrained the results show that an earthquake occurred on this fault 2800 300 yr ago we infer that this is the seismic event that destroyed ancient sparta in 464 b c four earlier earthquakes ruptured the sparta fault in the last 13 ka with similar slip amplitudes of about 2 m and with time intervals ranging from 500 yr to 4500 yr the observations also confirm that the sparta scarp is post glacial supporting the hypothesis that similar scarps elsewhere in the mediterranean region have a comparable age the absence of any event since 464 b c could suggest a future event is imminent however the irregularity of earthquake time intervals could also be due to changes of loading with important consequences for the mechanics of continental deformation

the use of distinct disciplines to investigate past earthquakes abstract the investigation of past earthquakes can be approached in many different ways with a large variety of methods and techniques this is mainly due to the complexity of this natural phenomenon in both its genetic aspects and consequential ones in the present note we briefly analyse the peculiarities of instrumental seismology historical seismology archaeoseismology and earthquake geology but especially we emphasise the major differences among these four distinct approaches in order to better define and clearly separate these disciplines in terms of appropriate tools to be applied and possible outcomes to be expected an alternative point of view is proposed based on the source of information and not on a chronological distribution as commonly accepted in the literature although multidisciplinarity is a common approach for investigating past earthquakes each one of the discussed disciplines has its own peculiarities advantages and limitations and researchers should be aware of this

tertiary extension of continental crust and uplift of psiloritis metamorphic core complex in the central part of the hellenic arc crete greece kinematic analysis of the deformation in central crete suggests that the structural evolution and exhumation of the high pressure low temperature hp lt rocks outcropping at the mount psiloritis metamorphic core complex are associated with a regional miocene north south extension and thinning of the continental crust this tectonic regime developed under bulk coaxial strain conditions with ductile deformation in the lower and brittle deformation in the upper crust and followed on the decompressional path a north south compression associated with a hp lt metamorphism in the lower crust this compressional event took place during oligocene early miocene and led to overthickening of the accretionary wedge in the hellenic arc an east west directed compression accompanied in the final stages the miocene north south extension of the continental crust

bookshelf faulting and horizontal block rotations between overlapping rifts in southern afar lateral slip on initially rift parallel normal faults may be a particularly efficient mechanism to accomodate strain between overlapping oceanic rifts it occurs in southern afar where clockwise block rotations result from distributed dextral shear between the overlapping ghoubbet asal manda inakir and manda hararo abhe bad rifts faulting observed during the 1969 serdo earthquakes and on spot images is consistent with the shear being taken up by left lateral slip on steep nw se striking faults which formed as normal faults before extensional strain became localized in the two rifts this bookshelf faulting accounts quantitatively for the 14 5 7 5 rotation documented by paleomagnetism in the 1 8 0 4 ma old afar stratoid basalts given the 17 5 5 mm yr rate of separation between arabia and somalia

east west extension and holocene normal fault scarps in the hellenic arc examination of surface fault traces with spot images and in the field corroborates the inference that the active tectonics of southern peloponnesus and crete are dominated by approximately north south normal faulting and approximately east west extension the heights of holocene normal fault scarps yield first order regional estimates of fault slip rates between 0 1 and 2 3 mm yr most of the surface scarps probably ruptured during past earthquakes such as that which destroyed sparta in 464 b c on the sparta fault the holocene average slip rate and the recurrence time of large earthquakes may be 1 mm yr and 3000 yr respectively the regional pattern of quaternary faulting suggests that the east west extension near the hellenic subduction zone is fast about 5 10 m y the change from north south to east west extension in the late pliocene 2 4 ma implies that the aegean is starting to collide with the northern margin of africa

a possible normal fault rupture for the 464 bc sparta earthquake surface ruptures have been identified for some normal faulting earthquakes in the aegean region1 3 but for most historical earthquakes the associated faults are unknown this hampers the evaluation of the rates and styles of present day deformation and the assessment of seismic hazard in the region4 here we examine the famous earthquake that destroyed sparta in 464 bc using spot satellite images and fieldwork we have mapped a 20 km long normal fault scarp trending approximately north south a few kilometres east of the ancient city our observations combined with an examination of historical descriptions of the earthquake damage suggest that the sparta earthquake ruptured this fault scarp in an event of magnitude ms 7 2 the holocene slip rate and the recurrence time for such large events on the sparta fault would be 1 mm yr 1 and 3 000 yr respectively

postnappe stacking extension and exhumation of high pressure low temperature rocks in the island of crete greece the island of crete consists largely of nappes of contrasting lithologies and metamorphism that were stacked southward during an oligocene early miocene n s compression with the lower nappes undergoing a high pressure low temperature hp lt metamorphism this was followed by a n s miocene crustal extension that caused thinning of the nappes and uplift of the hp lt metamorphic rocks ductile conditions took place in the lower nappes associated with a retrograde greenschist metamorphism while semiductile to brittle conditions took place in the upper nappes a major normal detachment fault separates the lower and the upper nappes the quartz texture analyses and the symmetry of structures indicate bulk coaxial deformation while the results of strain analysis suggest both constrictional and flattening strains a younger ne sw compression affected both the thinned nappe pile and the late miocene pliocene sedimentary basins finally a pliocene ne sw extension led to further uplift and exhumation of the hp lt metamorphic rocks this cyclic tectonometamorphic process of alternate compression and extension took place during the migration of the hellenic orogenic belt toward the most external units including successive tectonic events

temporally constant quaternary uplift rates and their relationship with extensional upper plate faults in south crete greece constrained with 36cl cosmogenic exposure dating in order to investigate how active upper plate faults in crete influence uplift above the hellenic subduction zone we mapped deformed late quaternary marine terraces along 17 profiles across strike of the south central crete fault sccf identified and dated palaeoshorelines using in situ 36cl exposure dating on wave cut platforms correlated them with the quaternary sea level curve and calculated uplift rates we identified 16 distinct palaeoshorelines from field observations and study of digital elevation models dems located along the footwall and hangingwall of the sccf and the footwall of the offshore ptolemy trench fault cosmogenic dating constrains the ages of three palaeoshorelines as 76 100 and 125 ka we use these dates to guide a correlation of other mapped palaeoshorelines with quaternary sea level highstands between 200 and 980 ka with results implying that the uplift rate is constant through time at each of the 17 profile locations elastic half space modelling implies that uplift in both the hangingwall and footwall of the sccf is influenced by uplift related to offshore upper plate faults in addition to background regional uplift perhaps from the subduction interface by correlating palaeoshorelines across the active south central crete fault we derive a throw rate of 0 41 mm yr for this fault which can also be expressed as a slip rate of 0 58 mm yr the fault specific earthquake recurrence interval assuming repetition of 1 1 m slip events is approximately 2700 years for the sccf

magnitude versus faults surface parameters quantitative relationships from the aegean region historical and seismotectonic data from the broader aegean region have been collected and all possible information relative to ground deformation associated to earthquakes that hit the area have been re evaluated all events associated to co seismic surface faulting have been selected and further investigated while geomorphologic and geological criteria have been used to recognise and characterise the seismogenic faults associated to these morphogenic earthquakes sensu bull inqua 16 1993 24 in particular in order to perform seismic hazard analyses we compiled a list of all earthquakes where the surface rupture length srl the maximum vertical displacement mvd or the average displacement ad is available we thus obtained reliable values of these source parameters for 36 earthquakes of which 26 occurred during the 20th century 6 in the 19th century and the 3 remaining earlier magnitude versus srl and mvd has been compiled for estimating empirical relationships the calculated regression equations are ms 0 90 log srl 5 48 and ms 0 5 9log mvd 6 75 showing good correlation coefficients equal to 0 84 and 0 82 respectively co seismic fault rupture lengths and especially maximum displacements in the aegean region have systematically lower values than the same parameters worldwide but are similar to those of the eastern mediterranean middle east region the envelopes of our diagrams are also calculated and discussed for estimating the worst case scenario furthermore for all investigated seismogenic structures based on several geological criteria we measured the geological fault length gfl which is the total length of the neotectonic faults showing cumulative recent activity we then compared srl with gfl and their ratio shows a clear bimodal distribution with a major peak at 0 8 1 0 indicating that about 50 of the investigated earthquakes ruptured almost the entire fault length while a second peak around the value of 0 5 is clearly related to a segmentation process of longer neotectonic structures further implications of this distribution are also discussed eventually from the distribution of gfl versus magnitude we also infer an important geological threshold for the occurrence of morphogenic earthquakes at about 5 5 degrees

precursory eruptive activity and implied cultural responses to the late bronze age lba eruption of thera santorini greece abstract the late bronze age lba eruption ca 1650 bce of thera santorini was one of the largest known in history burying and destroying a thriving theran cycladian culture that occupied the island and surrounding islands the consequent thick tephra deposit provides detailed information on the eruptive sequence and vent mechanics it also provides details on that culture through burial of towns farmsteads and landscapes the most prominent being the town of akrotiri on the south coast of thera here stratigraphic relationships between volcanic and archaeological deposits constructions clearly indicate this eruption was signaled by seismic and minor eruptive events precursory to the main plinian eruption because no casualties have yet been found beneath the tephra inhabitants had advance notice of the impending disaster by a precursory eruption whose deposits are well preserved both within the archaeological site and in geological exposures throughout southern thera island and escaped by boat yet archaeological sites on nearby islands rarely record an influx of new arrivals at this time accordingly it is suggested here that those escaping were incinerated at sea by pyroclastic density currents that swept across the ocean surface during the second phase of the plinian eruption

scales of structural heterogeneity within neotectonic normal fault zones in the aegean region abstract structural heterogeneities within neotectonic normal fault zones in the aegean region are important controls on the geomorphic expression of their uplifted footwall blocks contrasting fault rocks and slip plane phenomena corrugations comb fractures slip parallel fractures and pluck holes are responsible for mesoscopic inhomogeneities within fault scarps along strike disruptions in the continuity of fault scarps step over zones step up zones step down zones footwall cross faults and hangingwall cross faults are products of perturbations in slip plane geometry or intersections with transverse faults large scale variations in range front morphology reflect contrasting patterns of deformation within fault zones some major fault zones and many minor fault zones are characterized by a migration of the active slip plane towards the hangingwall resulting in a distributed network of high angle faults and a range front which is stepped in profile the presence of a localized mass of uneroded bedrock hangingwall salients protruding from the hangingwall of some major fault zones results in intense deformation along a principal slip plane and a range front which is ramp like in profile as a consequence of structural heterogeneities within neotectonic normal fault zones fault scarps and range fronts in the aegean region are subject to a temporally and spatially variable pattern of degradation

archaeoseismological studies on historical heritage sites in the gyeongju area se korea abstract recently a fallen buddha statue of the late 8th century was discovered in mt nam gyeongju se korea the gyeongju area is located in intersection of two major young structural features in korea the yangsan and ulsan faults according to historical records such as the ancient texts of samguksagi chaljubongi and mukseojipyeon the studied area was significantly affected by several large earthquakes of mm intensity vii and estimated magnitude up to m l 6 7 such as the destructive events occurred in 768 ad 779 ad and 1036 ad especially the last two earthquakes are historically well documented as triggering severe damages in other historical buildings hwangryongsa pagoda and bulguksa temple around the area this paper examines the potential connection between the fallen buddha statue and any of the large historical earthquakes documented in the area restoration study of the original position of the fallen buddha statue based on fracture analysis indicates that the fallen buddha statue rotated 20 clockwise and slid a few meters from its original position during a large rockfall event preliminary osl dating was carried out from weathered soil below a large granite block adjacent to the fallen statue the age of 0 76 0 12 ka indicates a bracketed time period between the years 1130 and 1370 ad for the statue fall however no earthquake is reported for this time period in the area although the available data does not exactly indicate any specific earthquake based on the historic records artistic styles differential weathering of the statue osl dating and nearby historically documented archaeoseismic damage the 1036 ad earthquake m l 6 4 is proposed as the more likely event responsible for the studied damage furthermore other earthquake damage to historic heritage sites was also reported in historical records around the study area therefore a future seismic hazard study should be carried out to preserve the important national heritage sites in this area the combination of paleoseismological and archaeoseismological studies is essential to estimate potential earthquake hazard in this area

faulting and effects of earthquakes on minoan archaeological sites in crete greece abstract examination of damages affecting the buildings of the archaeological sites of phaistos and agia triada southern crete suggests that these minoan settlements were probably destroyed by two major seismic events characterized by mks intensities of ix x and occurred at the end of the protopalatial 1700 bc and the neopalatial 1450 bc periods geological and morphological studies carried out in the neighbouring areas show the occurrence of e w trending quaternary normal fault segments spili and agia galini faults that control the present topography and morphology and exhibit steep young scarps mostly holocene in age these fault segments are related to a nw se extension direction which is consistent with that indicated by the available focal mechanisms of the earthquakes occurring in this area in the last 50 years combining structural and seismic data we can infer that the spili and agia galini fault segments could represent good candidates to be considered active faults generating large earthquakes m 6 5 that were responsible for the damages of phaistos and agia triada this hypothesis suggests that the minoan palatial centres were destroyed by several large earthquakes related to ruptures along distinct fault segments rather than by a single catastrophic event that caused the abrupt destruction of the minoan civilisation in the eastern mediterranean

multiseismic cycle deformation rates from holocene normal fault scarps on crete greece morphotectonic features reveal recent seismic activity on normal faults on crete allowing slip rates palaeoearthquake magnitudes and earthquake recurrence intervals to be inferred the studied faults show major escarpments 100s m high 10s km long separating uplifted mesozoic rocks from quaternary deposits during the holocene slip rates outpaced erosion sedimentation rates and 5 15 m high fresh scarps formed at the base of the major escarpments based on our field observations and following empirical relationships between magnitude surface rupture length and maximum co seismic vertical displacement it is possible to infer some important seismotectonic parameter relative to the investigated faults taking into account the possible sources of error and the corresponding uncertainties our preferred long term slip rates range between 0 5 and 1 3 mm yr 1 the maximum expected magnitudes between 6 3 and 6 6 or 6 5 and 6 8 considering worst case scenarios while the mean recurrence intervals range between 260 and c 840 years these estimates are in good agreement with the shallow seismicity thus allowing to improve our knowledge on the seismic potential in crete horizontal extension rates could be also inferred from our geological data and compared with the few available gps data

active faulting on the island of crete greece in order to characterize and quantify the middle late quaternary and ongoing deformation within the southern aegean forearc we analyse the major tectonic structures affecting the island of crete and its offshore the normal faults typically consist of 4 30 km long dipslip segments locally organised in more complex fault zones they separate carbonate and or metamorphic massifs in the footwall block from loose to poorly consolidated alluvial and colluvial materials within the hangingwall all these faults show clear evidences of recent re activations and trend parallel to two principal directions wnw ese and nne ssw based on all available data for both onland and offshore structures morphological and structural mapping satellite imagery and airphotographs remote sensing as well as the analysis of seismic profiles and the investigation of marine terraces and holocene raised notches along the island coasts for each fault we estimate and constrain some of the principal seismotectonic parameters and particularly the fault kinematics the cumulative amount of slip and the slip rate following simple assumptions and empirical relationships maximum expected magnitudes and mean recurrence periods are also suggested summing up the contribution to crustal extension provided by the two major fault sets we calculate both arc normal and arcparallel long term strain rates the occurrence of slightly deeper and more external low angle thrust planes associated with the incipient continental collision occurring in western crete is also analysed although these contractional structures can generate stronger seismic events m 7 5 they are probably much rarer and thus providing a minor contribution to the overall morphotectonic evolution of the island and the forearc a comparison of our geologicallybased results with those obtained from gps measurements show a good agreement therefore suggesting that the present day crustal deformation is probably active since middle quaternary and mainly related to the seismic activity of upper crustal normal faults characterized by frequent shallow 20 km moderate to strong seismic events seldom alternating with stronger earthquakes occurring along blind low angle thrust planes probably ramping from a deeper aseismic detachment ca 25 km this apparently contradicting co existence of juxtaposed upper tensional and lower compressional tectonic regimes is in agreement with the geodynamics of the region characterised by continental collision with nubia and the aegean mantle wedging

recognition of earthquake related damage in archaeological sites examples from the dead sea fault zone abstract archaeological structures that exhibit seismogenic damage expand our knowledge of temporal and spatial distribution of earthquakes afford independent examination of historical accounts provide information on local earthquake intensities and enable the delineation of macroseismic zones they also illustrate what might happen in future earthquakes in order to recover this information we should be able to distinguish earthquake damage from anthropogenic damage and from other natural processes of wear and tear the present paper reviews several types of damage that can be attributed with high certainty to earthquakes and discusses associated caveats in the rare cases where faults intersect with archaeological sites offset structures enable precise determination of sense and size of slip and constrain its time among the characteristic off fault damage types i consider horizontal shifting of large building blocks downward sliding of one or several blocks from masonry arches collapse of heavy stably built walls chipping of corners of building blocks and aligned falling of walls and columns other damage features are less conclusive and require additional evidence e g fractures that cut across several structures leaning walls and columns warps and bulges in walls circumstantial evidence for catastrophic earthquake related destruction includes contemporaneous damage in many sites in the same area absence of weapons or other anthropogenic damage stratigraphic data on collapse of walls and ceilings onto floors and other living horizons and burial of valuable artifacts as well as associated geological palaeoseismic phenomena such as liquefaction land and rock slides and fault ruptures additional support may be found in reliable historical accounts special care must be taken in order to avoid circular reasoning by maintaining the independence of data acquisition methods

upper crust reworking during gravitational collapse the bembibre pico sacro detachment system nw iberia abstract the kinematics of the basal allochthon in the sw of the ordenes complex is analysed to constraint its evolution during collisional and postcollisional stages of the variscan orogeny two distinct sequences have been identified in the basal allochthon of this sector the upper and lower sequences in close correlation with the subdivision of the basal allochthon in the malpica tui complex three main tectonic episodes have been established in the basal allochthon a high pressure event related to continental subduction a mesozonal event of regional exhumation by thrusting and recumbent folding and a regional scale extensional episode that resulted in the development of the bembibre pico sacro detachment system the bembibre pico sacro system rejuvenated pre existing shear zones whose weakness favoured the nucleation of the detachments shear zones associated with the detachments overprinted the previous tectonic fabrics under conditions ranging from lower amphibolite to greenschist facies and with heterogeneously distributed ductile to brittle deformation the detachment system is coeval with late orogenic collapse and widespread magmatism and represents its upper crustal expression it correlates with mid and lower crustal flow and the development of gneiss domes at depth in such a way that the basal allochthon can be considered a rheological boundary between the more rigid allochthonous sequences above and the more viscous schistose domain and autochthon below

active oblique extension in the central apennines italy evidence from the fucino region the fucino basin is a flat quaternary depression within the central apennines it is surrounded by active normal faults with small oblique slip components surface faulting was observed along the east side of the basin during the ms 7 0 avezzano earthquake of 1915 in order to understand the kinematics of recent strain better and to assess the seismic hazard of this region we carried out a detailed geomorphic and structural study of the faults around the basin fault scarp heights were accurately measured with total station profiles and vertical slip rates were estimated assuming slope offsets to post date the end of periglacial abrasion 14 4 kyr bp to the north the most prominent fault the magnola fault appears to have an average postglacial throw rate of 0 7 0 3 mm yr 1 and together with the velino fault to be capable of generating earthquakes of maximum magnitudes of 6 9 7 3 with recurrence intervals of 1000 3000 yr east of the basin the serrone parasano and ventrino faults form a right stepping horsetail of the giovenco fault current vertical slip rates on the three former faults appear to be between 0 5 and 1 4 0 5 and 1 0 and 0 3 and 1 1 mm yr 1 respectively infrequent maximum magnitude earthquakes on them may also exceed 7 particularly in the case of coupled rupture with loosely constrained recurrence intervals up to several thousand years the right lateral slip components implied by the most recent slickensides and by geomorphic offsets on the nw se trending normal faults of the area suggest that the blocks they bound rotate counterclockwise consistent with oblique left slip on the nnw sse trending giovenco and ovindoli faults to the east sinistral shear parallel to the latter faults the maximum relief across the magnola fault and the postglacial slope offsets measured suggest that the extension rate across the central apennines might be of the order of 6 3 mm yr 1 in a n20 10 e direction more northerly than hitherto inferred

vertical land movements and sea level changes along the coast of crete greece since late holocene abstract geomorphological survey along the coasts of crete revealed widespread evidence of uplifted and submerged tidal notches different phases of beachrock formation and many relics of ancient coastal constructions about 1 6 ka bp when the sea level was at 1 25 0 05 m the western tectonic block of the island uplifted by 9 15 0 20 m in its westernmost extremity and by 2 00 m approximately in its eastern boundary and tilted southeastward repeated preceding episodes of subsidence submerged the western part of the island by 1 60 m in a period of 2300 years along the western coast the younger phase of the submerged beachrocks was identified and measured at nineteen locations together with the submerged tidal notches and archaeological remains land subsidence by 1 25 0 05 m subsequent to the uplift of the western part occurred after the late venetian occupation period ad 1600 coincident with the submersion of the eastern part of the island in central and eastern crete the relative sea level change evidence from tidal notches and beachrocks revealed five distinct sea level stands at 6 55 0 55 m 3 95 0 35 m 2 70 0 15 m 1 25 0 05 m and 0 55 0 05 m the lowest sea level stand can be identified with the oldest dated tidal notch of western crete between 4200 90 b p and 3930 90 b p two subsequent sea levels can be linked with the protopalatial 1900 1700 b c or 1600 b c and neopalatial period 1600 1450 b c of the minoan civilization according to submerged prehistoric morphologies and inundated minoan constructions the change of sea level from 2 70 0 15 m to 1 25 0 05 m is placed between 1450 b c and the fourth century bc the dating of 1 25 0 05 m sea level stand was based on the measurement and interpretation of ancient coastal installations built along the coast of central and eastern crete during classical hellenistic roman byzantine and venetian periods historical sources report a relative sea level rise by 0 70 m during the ad 1604 paroxysmal event over the last 400 years the relative sea level rose by 0 55 m the uplift of the coast of western crete and the submersion in its central and eastern coast indicate that during the ad 365 paroxysmal event the island was split along a tectonic boundary identified with the neotectonic graben of spili and its northern and southern prolongation

the ad 365 crete earthquake and possible seismic clustering during the fourth to sixth centuries ad in the eastern mediterranean a review of historical and archaeological data abstract historical and archaeological data are used to test geological claims that in the fourth to sixth centuries ad the eastern mediterranean experienced an unusual clustering of destructive earthquakes the early byzantine tectonic paroxsym a review of historical accounts of a notable earthquake at this time that of 21 july ad 365 indicates that this event destroyed nearly all the towns in crete and was followed by a tsunami which devastated the nile delta the ad 365 event was also probably responsible for reported or observed destruction in ancient towns of west cyprus and libya this earthquake is most likely to be identified with a hellenic arc subduction zone event of great m 8 magnitude as testified by up to 9 m of uplift in western crete dated by previous geological studies to around this time historical and archaeological data also support the hypothesis that the fourth to sixth centuries ad was a period of abnormally high seismicity in the eastern mediterranean the high seismicity rates of this period may reflect a reactivation of all plate boundaries in the region dead sea transform east anatolian fault north anatolian fault hellenic arc cyprus arc fault

faulting and earthquake triggering during the 1783 calabria seismic sequence summary between the 1783 february 5 and 1783 march 28 five earthquakes struck the southern part of calabria the main shock february 5 and the first aftershock february 6 devastated the region ene of the messina strait the greatest damage occurred along the foot of the aspromonte mountains south of san giorgio morgeto and along the tyrrhenian coast south of palmi a surface break about 18 km long with several feet of downthrow to the west formed along the cittanova santa cristina fault as a result of the main shock on february 7 a third large shock ruined villages at the foot of the serre mountains north of san giorgio morgeto morphological and structural evidence combined with a reassessment of observations made at the time of the earthquakes suggest that these three shocks were shallow 20 km and related to slip on the west dipping ne striking cittanova sant eufemia palmi scilla and serre normal faults respectively which juxtapose the basement of the aspromonte and serre mountains with the pleistocene deposits of the gioia tauro and mesima basins and border the palmi coastal high the three faults belong to an active rift that stretches from northern calabria to offshore the ionian coast of sicily the spatial coupling between the 1783 events is investigated by resolving changes of coulomb failure stress the main shock 1783 february 5 m 7 on the cittanova and sant eufemia faults increased that stress by several bars on the scilla fault triggering the 1783 february 6 earthquake m 6 5 the cumulative effect of these two shocks was to raise the coulomb stress by more than 1 bar on the sw part of the serre fault which was subsequently the site of the 1783 february 7 shock m 6 5 in turn the first three events increased the stress by about 1 bar on the ne part of this latter fault leading to the 1783 march 1 shock m 5 7 the gap between the 1783 february 7 and 1783 march 1 events may be related to the previous occurrence of an earthquake 124 yr before 1659 november 5 m 6 which had already released stress locally the occurrence of the last 1783 event 28 march is not as simply accounted for by coulomb modelling in part because it remains unclear which fault slipped and how deep this event was overall the 1783 sequence increased the coulomb failure stress by several bars south of the messina strait and north of the epicentral region of the 1693 se sicily catania noto earthquakes 125 yr later this same region was the site of the 1908 messina earthquake also a normal faulting event our study thus provides one convincing example in which coulomb stress modelling brings insight into the spatial dynamics of seismic sequences