geomorphic and biological indicators of paleoseismicity and holocene uplift rate at a coastal normal fault footwall western corinth gulf greece abstract the westernmost part of the gulf of corinth greece is an area of very fast extension and active normal faulting accompanied by intense coastal uplift and high seismicity this study presents geomorphic and biological evidence of holocene coastal uplift at the western extremity of the gulf where such evidence was previously unknown narrow shore platforms benches and rare notches occur mainly on holocene littoral conglomerates of uplifting small fan deltas they are perhaps the only primary paleoseismic evidence likely to provide information on earthquake recurrence on coastal faults in the specific part of the rift whereas dated marine fauna can provide constraints on the average holocene coastal uplift rate the types of geomorphic and biological evidence identified are not ideal and there are limitations and pitfalls involved in their evaluation in a first approach 5 uplifted paleoshorelines may be identified at 0 4 0 7 1 0 1 3 1 4 1 7 2 0 2 3 and 2 8 3 4 m a m s l probably forming after 1728 or 2250 cal b p a most conservative estimate for the average coastal uplift rate during the late holocene is 1 6 or 1 9 mm yr minimum with different amounts of reservoir correction some of the obtained radiocarbon ages of lithophaga sp allow for much higher holocene uplift rates of the order of 3 4 mm yr which cannot be discarded but require further research that the identified paleoshoreline record corresponds to episodes of coastal uplift only cannot be demonstrated beyond all doubt yet it appears the most likely interpretation given the geological and active tectonic context and present knowledge on eustatic sea level fluctuations in the mediterranean proving that the documented uplifts were abrupt i e arguably coseismic is equally difficult but rather probable five earthquakes in the last ca 2000 yr on the coastal fault zone that is responsible for the uplift compare well with historical seismicity and the results of recent on fault paleoseismological studies at the nearby eliki fault zone exact amounts of coseismic uplift cannot be determined precisely unless the rate of non seismic uplift of northern peloponnesus at the specific part of the corinth rift is somehow constrained

fault death a perspective from actively deforming regions abstract patterns of activity on large faults in regions of distributed continental deformation can change quite rapidly in less than 1 ma such changes include faults becoming permanently or temporarily inactive spatial migration of activity between different faults or faults sets within a deforming region and faults apparently going through episodes of intense activity separated by long quiescent periods greater knowledge of these changes combined with our increasingly detailed understanding of the geometry of large faults have implications for a variety of structural and tectonic issues such as 1 the nature of the interaction between neighbouring faults 2 the link between the discontinuous deformation on faults in the seismogenic upper crust and the more distributed deformation in the aseismic lithosphere beneath and 3 the relation between the instantaneous kinematics and the cumulative finite deformation examples from the active extensional province of central greece are used to illustrate the nature and possible significance of changing fault patterns

holocene raised shorelines on the hatay coasts turkey palaeoecological and tectonic implications abstract the marks of two emerged shorelines superimposed erosional notches and in situ bioconstructed rims with the vermetid dendropoma on both sides of the orontes delta near the border between turkey and syria are interpreted as representing the occurrence of two rapid uplifts during the late holocene rather than representing eustatic fluctuations of climatic origin as claimed by previous authors in other areas of the eastern mediterranean the upper shoreline which has an elevation of about 2 0 m south of the delta and which increases from 2 5 m to 3 0 m between 2 and 8 km north of the delta has been radiocarbon dated four dates to between 5170 190 and 2595 100 yrs b p the lower shoreline indicating a former relative sea level situated consistently at about 0 7 to 0 8 m has yielded seven dates between 2910 95 and 1345 70 yrs b p the latter age being that of fossil oyster shells collected in growth position on a quay of the ancient harbour of seleucia pieria if the possible contamination of some oyster shells is taken into account the two uplift movements may be dated at around 2500 100 yrs b p for the upper shoreline and to historical times for the lower shoreline probably in july 551 a d when devastating earthquake damage was reported from all the levant regions the age of the second uplift movement falls within the possible time span of a major tectonic event the early byzantine tectonic paroxysm ebtp which about 1500 yrs b p caused sudden relative sea level changes in various areas of the eastern mediterranean antikythira western crete and alanya area the lebanon northern cyprus etc in the hatay region the effect of the ebtp has been a reactivation of local fault lines probably in connection with movements on the east anatolian fault system this has contributed a new jerk to the long term trend of uplift in this coastal area

coastal uplift on active normal faults the eliki fault greece the eliki fault forms part of a system of major normal fault segments that borders the southern margin of the gulf of corinth half graben radiocarbon dating of elevated marine fossils reveals broadly uniform holocene coastal uplift at a time averaged rate of 1 5 mm yr both along the eliki fault and in the transfer zone that separates it from the neighbouring fault segment coseismic uplift increments are considered to account for only a minor part of the 6 m of emergence recorded here in the last 3000 years reappraisal of shoreline data from the perachora peninsula at the eastern end of the gulf of corinth indicates a similar though less rapid 0 7 mm yr pattern of uniform holocene emergence as these holocene coastal records embody both coseismic and interseismic deformation they can be used to characterise long term tectonic strain

holocene and quaternary uplift in the central part of the southern coast of the corinth gulf greece abstract the southern coast of the gulf of corinth greece has long been recognized as an area of rapid quaternary uplift in a normal faulting environment but the amplitude dating and significance of this uplift remain a matter of debate mainly due to the scarcity of reliable and detailed estimates of holocene and longer term uplift evidence of holocene emergence is analysed for two sites in the most uplifted area of the southern coast of the gulf of corinth at mavra litharia the uppermost holocene marine limit has been identified at 9 3 m and dated about 7100 14 c years bp near platanos where the holocene marine limit is above 12 5 m in situ infralittoral boring shells at 11 5 m have been dated about 4800 14 c years bp average uplift rates can be estimated between 2 9 and 3 5 mm year at mavra litharia and possibly even greater ca 2 1 2 7 mm year near platanos the pattern of the variation of holocene uplift along the coast seems to mimic the pattern of late quaternary terraces well constrained in the eastern pattern of the gulf corinth xylokastro area

boulders transport by catastrophic waves along the ionian coast of apulia southern italy abstract several tracts of the ionian coast of apulia southern italy are characterized by large boulders up to 80 t in weight scattered some meters above present sea level the largest boulder is about 80 t in weight and slid for about 40 m from the mean sea level up to about 1 8 m of altitude elongated boulders show a remarkably narrow range of orientation of the long axis as well as of the imbrication axis suggesting that they had been transported by a single catastrophic event most likely a tsunami connected to a wave train approaching the coast from the south stratigraphic morphological and historical data suggest that this event occurred during the late holocene conventional radiocarbon age determination performed on lithophag shells collected from a large boulder yielded a calibrated age between 1421 and 1568 a d then the catastrophic wave train probably a tsunami could be a local effect of the strong earthquake which hit southern italy on december 5th 1456

seismic coastal uplift in a region of subsidence holocene raised shorelines of samos island aegean sea greece abstract at least three raised shorelines micro benches and notches spanning a distance of more than 10 km and marked by a well preserved marine fauna have been identified along the nw coast of samos island aegean sea and area hitherto assumed to be characterised by a holocene marine transgression these fossil shorelines are nearly horizontal approximately 0 6 1 1 and 2 3 m above sea level and can be assigned to hitherto unnoticed earthquakes which occurred approximately 500 3600 3900 and possibly 1500 years ago some evidence of quaternary and longer term uplift has been found as well the observed uplift may be related to a zone of intense seismicity and faulting following the great meander buyuk menderes river graben in western anatolia but its structural explanation is not clear new evidence indicates that the geomorphological evolution of samos island and of the wider eastern aegean is not simply a result of marine transgression and of regional scale tectonics but also of earthquakes and that local scale tectonics are responsible for the evolution and present day morphology of at least a part of the coast of samos island as well as of other aegean coasts

crustal block movements from holocene shorelines rhodes island greece abstract signs of up to eight stepped holocene shorelines which have been reported in a previous study on the east coast of rhodes island have been reinvestigated in detail on the basis of a new geomorphological survey identification and petrological analysis of many new samples of exposed marine organic crusts and over 30 radiocarbon datings confirmation was obtained of the view that the island can be charactered by considering small crustal blocks up to a dozen kilometres long with each block being affected by a specific tectonic history and a general trend towards an uplift increasing from south to north two successive phases of submergence emergence have been revealed by petrogenetic sequences in many samples which give evidence of the occurrence of positive and negative vertical movements this implies possible rejuvenation effects of the later submergence phase on the apparent age of pre existing algal crusts and those have been taken into account and estimated the most likely sequence of vertical crustal movements to have occurred has been specified for each block and a time range has been ascribed to each former shoreline independent up and down movements increasing in amplitude from south to north appear in most blocks there is a recurrent periodicity varying from a few hundred to one or at most two thousand years the largest vertical displacement observed during the late holocene a sudden uplift movement of about 3 8 m in the northernmost part of the island is likely to be linked with the earthquake which destroyed the colossus in 222 b c

geoscience of ancient mediterranean harbours abstract although much has been written on the subject of ancient mediterranean harbours the relatively new area of harbour geoarchaeology remains dispersed in the geoscience and archaeological literature over a decade of research has amassed rich and varied datasets of anthropogenically forced coastal evolution with a remarkable number of between site analogies this new research field also shows the rich potential of geoscience to reconcile important archaeological questions no single publication however has yet drawn on these geological patterns to yield a detailed overview suitable for geoscientists and environmental archaeologists the aim of this review article is to 1 discuss how ancient harbours have come to be preserved in the geological record 2 expound the basic principles and palaeoenvironmental tools underpinning ancient harbour geoarchaeology 3 outline some of the most significant research advances made and 4 discuss a new chrono stratigraphic model applicable to harbour sequences

earthquake clustering in the eastern mediterranean during historical times most coastal sectors which show evidence of holocene coseismic uplift in greece and the eastern mediterranean were raised during a short period called here the early byzantine tectonic paroxysm ebtp between the middle of the fourth and the middle of the sixth century a d the areas uplifted at that time include cephalonia and zante in the ionian islands lechaion and the perachora peninsula in the gulf of corinth the pelion coast of thessaly antikythira and the whole of western crete a coastal sector near alanya in southern turkey and the entire levant coast from hatay turkey to syria and the lebanon the amount of the ebtp uplift was generally between 0 5 m and 1 0 m but reached a maximum of about 9 m in southwestern crete in several areas zante pelion coast antikythira western crete alanya the ebtp uplifted shoreline is the only evidence of holocene emergence in other areas however a similar uplift occurred earlier in the holocene levant coast or more recently cephalonia evidence of preseismic subsidence prior to the ebtp uplift has been reported from thessaly antikythira and crete in both the latter islands the ebtp uplift was preceded by a series of about 10 coseismic small subsidence movements each measuring some tens of centimeters which took place in the preceding 3000 years no evidence was observed of postseismic vertical displacements

the role of strong earthquakes and tsunami in the late holocene evolution of the fortore river coastal plain apulia italy a synthesis abstract morphological analysis of the fortore river coastal plain and the lesina lake coastal barrier integrated with radiocarbon age data indicates that the evolution of the coastal landscape has been strongly affected by a number of strong earthquakes and related tsunamis which occurred during the last 3000 years the first seismic event struck this coastal area in the v century bc it produced strong erosion of the fortore river coastal plain and significant emersion of punta delle pietre nere as well as the large tsunami responsible for the development of the sant andrea washover fan the second event occurred in 493 ad it induced severe erosion of the fortore river coastal plain and triggered the large tsunami that hit the lesina lake coastal barrier producing the foce cauto washover fan then later in 1627 an earthquake was responsible for the further coseismic uplift of punta delle pietre nere the subsidence of lesina village area and the development of a tsunami which produced two washover fans morphological analysis points out that seismic events strong enough to control the morphological evolution of local coastal landscapes show a statistical return period of about 1000 years these major events produced important coseismic vertical movements and large tsunamis however the correct identification of the tectonic structure responsible for the generation of these strong earthquakes is still an unsolved problem

mid to late holocene shoreline reconstruction and human occupation in ancient eretria south central euboea greece few studies have aimed to reconstruct landscape change in the area of eretria south central euboea greece during the last 6000 years the aim of this paper is to partially fill in this gap by examining the interaction between mid to late holocene shoreline evolution and human occupation which is documented in the area from the late neolithic to the late roman period with discontinuities evidence of shoreline displacements is derived from the study of five boreholes maximum depth of 5 25 m below the surface drilled in the lowlands of eretria based on sedimentological analyses and micro macrofaunal identifications different facies have been identified in the cores and which reveal typical features of deltaic progradation with marine lagoonal fluvio deltaic and fluvial environments in addition a chronostratigraphy has been obtained based on 20 ams 14c radiocarbon dates performed on samples of plant remains and marine lagoonal shells found in situ the main sequences of landscape reconstruction in the plain of eretria can be summarized as follows a marine environment predominated from ca 4000 to 3200 cal bc and a gradual transition to shallow marine conditions is observed ca 3200 3000 cal bc due to the general context of deltaic progradation west of the ancient city subsequently from ca 3000 to 2000 cal bc a lagoon occupied the area in the vicinity of the temple of apollo and the settlement s development was restricted to several fluvio deltaic levees thus severely limiting human activities in the plain from ca 2000 to 800 cal bc a phase of shallow marine presence prevailed and constrained settlement on higher ground forcing abandonment of the major part of the plain finally since the eighth century bc the sea has regressed southward and created the modern landscape

the influence of warm core rings on slope water entering the gulf of maine the seasonal baroclinic circulation in the gulf of maine is partly determined by the distribution of dense water that enters from the continental slope and spreads over sills into the deep basins of the gulf the slope water enters the gulf as an intermittent deep flow through the northeast channel which provides the principal connection with the atlantic ocean warm core rings from the gulf stream occasionally approach the mouth of the northeast channel and at times ring water contributes to or modifies the inflowing slope water for example sequential surveys in june and july of 1986 showed that a ring streamer crowded against georges bank and brushed obliquely across the channel mouth the resulting inflow in july flooded the channel mouth with streamer modified slope water which overwhelmed the more usual maine intermediate water outflow noted 1 month earlier compared to previous years relatively little slope water was found inside the gulf in june 1986 and it is tempting to speculate that a delayed spin up of the interior baroclinic circulation began with the major inflow episode observed in july warm core rings from the gulf stream may influence the timing intensity and structure of the circulation and dependent processes that develop each year in the gulf of maine a test of this hypothesis will require long term monitoring of the northeast channel region coupled with seasonal hydrographic surveys and current measurements at strategic locations inside the gulf of maine

radiometric dates of uplifted marine fauna in greece implications for the interpretation of recent earthquake and tectonic histories using lithophagid dates n ad 365 a great mw n 8 earthquake lifted up western crete exposing a shoreline encrusted by marine organisms and up to 10 m of marine substrate beneath it radiocarbon ages determined for corals and bryozoans exposed between the paleo shoreline and present sea level are consistent within measurement error with each other and with the date of the earthquake but radiocarbon ages determined for the boring bivalve lithophaga lithophaga found on the same substrate are at least 350 years and up to 2000 years older than the date of the earthquake that lifted them above sea level these observations reveal two important effects that limit the use of radiocarbon lithophagid ages in tectonic and paleoseismological studies the first is that the exceptional preservation potential of lithophagids allows them to remain intact and in situ long after natural death while the substrate continues to be colonised until eventual uplift the second which we confirm with radiocarbon analysis of museum specimens of known age is the incorporation of old 14c free carbon into lithophagid shells from the limestone host rock into which the lithophagids bored the two effects are both significant in crete and central greece and can cause the radiocarbon lithophagid ages to be up to 2000 years older than the uplift event which exposed them understanding these effects is important because lithophagids are far more abundantly preserved and used to date uplift than most other marine organisms this study shows that they can rarely be used to distinguish uplift events or date them to better than 1000 years or even to distinguish whether observed uplift occurred in a single or in multiple events after taking account of these uncertainties the ages of the lithophagids are however consistent with the hypothesis that the highest prominent marine notches and exposed lithophagid holes within a few metres of sea level in greece formed when sea level became relatively stable 6000 years ago following rapid rise after the last glacial maximum

transverse fault zones of subtle geomorphic signature in northern evia island central greece extensional province an introduction to the quaternary nileas graben abstract reconnaissance level geomorphological observations in the northern part of evia euboea island suggest that a major topographic feature the 17 km long and 15 km wide nileas depression ndpr corresponds to a previously undetected graben structure bounded by fault zones of ene wsw to ne sw general strike these fault zones have been active in the quaternary since they affect the neogene deposits of the limni histiaia basin they strike transverse to the nw se active fault zones that bound northern evia in the specific area and are characterised along most of their length by subtle geomorphic signatures in areas of extensive forest cover and poor exposure the ndpr was formed during the early middle quaternary after the deposition of the neogene basin fill during the middle late quaternary the nw se fault zones that bound northern evia have been the main active structures truncating and uplifting the ndpr to a perched position in relation to the northern gulf of evia graben and the submarine basin on the aegean side of the island the present day morphology of the ndpr with an interior floor comprised of middle pleistocene erosional surfaces extensively dissected by drainages was shaped by erosion during this uplift judging from their geomorphic signatures the fault zones that bound the ndpr must have been characterised by low or very low rates of activity during the late quaternary yet that they may still be accommodating strain today is suggested by moderate earthquakes that have been recorded within the ndpr the fault zone at the se flank of the ndpr prokopi pelion fault zone may be very important in terms of earthquake segmentation of the active nw se dirfys fault zone that controls the aegean coast of northern evia given that the intersection between the two presents striking morpho structural similarities with the intersection of two fault zones with the same directions on the mainland the atalanti and hyampolis fault zones which is known to have acted as a barrier to the propagation of the atalanti earthquake ruptures in 1894

satellite detection of an unusual intrusion of salty slope water into a marginal sea using smap to monitor gulf of maine inflows abstract satellite salinity from the soil moisture active passive smap mission and in situ observations are used to diagnose the source of a significant increase in warm and salty surface water entering the gulf of maine gom in the winter of 2017 2018 smap salinity anomaly data indicate that this event was related to a salty feature that moved along the northwestern atlantic shelf break from near the grand banks southwest towards the gom over eight months before entering the gulf in december 2017 to january 2018 satellite altimetry sea surface salinity and sea surface temperature data suggest that before entering the gom the salty feature interacted with gulf stream meanders and eddies several times helping to sustain the water mass it is likely that feature interactions with a warm gulf stream meander took place in the fall of 2017 helping to advect high salinity water onto the shelf and then into the gom as a surface trapped feature in late fall 2017 according to satellite salinity data this episode led to significant salinification about 1 psu in the northeastern gom interior gom buoy salinity data agree in showing four months of increased gom salinity of the upper 50 m starting in november 2017 buoy t s analyses characterize this surface inflow as modified warm atlantic slope water typically seen only below 100 m and previously unobserved at the surface in the 15 year buoy record this new salty water circulated cyclonically along the gom coastline and mixed into the deeper gulf through february 2018 its intrusion may have also enhanced the cyclonic winter circulation in the gulf gom surface salinity anomalies ended abruptly in early march 2018 coincident with the occurrence of a bomb cyclone and its associated strong upper ocean mixing

vertical displacement trends in the aegean coastal zone ne mediterranean during the holocene assessed by geo archaeological data trends in the vertical displacement i e uplift or subsidence of the aegean sea coastal zone have been assessed by comparing observational data with those derived from the predictive glacio hydro isostatic model of lambeck and purcell 2005 for a period spanning from the mesolithic to the late roman times the data base comprises published studies that use both geomorphological with associated biological material and archaeological sea level indicators markers localities demonstrating uplift of high amplitude were detected in front of the hellenic arc antikythira crete rhodes nisyros and in the northeast aegean region thrace whilst areas experiencing tectonic subsidence were mainly observed in the central aegean region which is characterized by an extensional tectonic domain however regional scale tectonic particularities have caused uplift in parts of the west and east coast of central aegean tectonically stable sites can be found in the cyclades plateau however this is due to a bala

geoarchaeology of ancient aulis boeotia central greece human occupation and holocene landscape changes abstract this article presents the results of a coring operation which brought to light new evidence for the evolution of the coastal plain of aulis boeotia central greece in the holocene thanks to homer aulis is best known as the gathering point of the achaean fleet before it sailed to troy and a sanctuary of the goddess artemis ancient sources and archaeological evidence suggest the presence of an ancient marine bay potentially used as a harbor in the course of investigation we drilled two cores to a maximum depth of 4 20 m in the marshy lowlands and performed mollusc and micro paleontological identifications laser grain size analyses and magnetic susceptibility measurements in order to reveal the facies evolution of the area we obtained a chronostratigraphy sequence through a series of seven ams 14 c radiocarbon dates our study shows that the area was affected by a shallow marine incursion from the first half of the 6th millennium bc and gradually turned into a succession of shallow marine lagoon environments from ca 5000 cal bc to the 2nd century ad and into a confined lagoon environment during the roman and byzantine periods

benthic foraminifer palaeoecology of the late quaternary continental outer shelf of a landlocked marine basin in central aegean sea greece abstract north evoikos gulf greece constitutes a landlocked epicontinental and semi enclosed basin connected to the central west aegean sea through a strait probably not allowing full exchange of intermediate and deep water masses benthic foraminifer analyses were carried out on a late quaternary core from the outer shelf of the basin with the aim of tracing palaeoceanographic changes the benthic foraminifer species percentage per sample was used to calculate two main biological proxies the benthic foraminifer oxygen index bfoi and benthic foraminifer high productivity bfhp proxy estimated by grouping benthic foraminifer taxa which are known to flourish under high corg flux the estimated values of bfhp and bfoi were controlled mainly by the abundance of bolivinid species which are generally considered as opportunistic and shallow infaunal species tolerant to low oxygen conditions the statistical analysis q mode cluster analysis singled out four time intervals each characterized by certain levels of oxygenation and food availability time interval 1 8513 8300 cal bp is characterized by a mixed fauna of oxyphilic taxa and taxa that live in suboxic environment indicating the existence of a relatively eutrophic system with a well oxygenated sediment water interface time interval 2 8300 8100 cal bp records a deterioration of conditions on sea floor testified by significant oxygen and biotic diversity decrease benthic foraminifer composition in time interval 3 8100 7000 cal bp depicts environmental conditions still highly variable yet with faunal indication of more stable conditions than during the previous interval finally the benthic foraminifer assemblage of time interval 4 7000 3500 cal bp is related to the high food supply and good bottom circulation the data suggest a strong linkage between the quantity and quality of the organic matter supplies and the diversity and composition of the benthic foraminifer faunas moreover this study clearly demonstrates that vertical tectonic movements need to be taken into account when reconstructing the late quaternary palaeoceanography of this region

the continuity of active fault systems in greece summary evidence from geomorphology the distribution of large earthquakes and geodetic measurements suggests that the active faulting in mainland greece and the north aegean sea is concentrated into a small number of discrete linear zones that bound relatively rigid blocks on land the zones are most clearly identified where the faulting is associated with large escarpments particularly in hard footwall rocks the zones can become indistinct and diffuse near their ends sometimes because they enter high unstable topography where landsliding obscures the fault morphology but mostly because the extension rates decrease along strike as a consequence of the relative rotation of the blocks they bound the main graben systems of chalkidiki southern thessaly and the north gulf of evia all seem to connect with the strike slip faulting in the offshore aegean and to die out in the west a configuration related to clockwise rotations in east central greece by contrast the gulf of corinth which is the fastest opening graben system in greece opens more rapidly in the west than the east both these features of the gulf of corinth are consequences of the motion of the south aegean and peloponnese as a single block late pliocene and quaternary geology and geomorphology indicate that the boundaries of the rigid blocks in central greece have changed over that time with faulting migrating into the hanging walls sometimes changing in orientation these changes are probably related to the way faulting in the seismogenic layer adapts to block rotation so as to maintain the general features of a velocity field that is controlled by larger scale effects such as buoyancy forces and the seaward migration of the subducting slab beneath crete the image of greece as a mosaic of rigid blocks whose boundaries change with time is a useful framework for seismic hazard evaluation but we emphasize that some moderate sized earthquakes do occur away from the main fault zones within the relatively rigid blocks and especially near their diffuse ends

the use of engineering seismological models to interpret archaeoseismological findings in tolbiacum germany a case study archaeological excavations carried out from 2001 to 2003 at the vicus tolbiacum site located in the present day city of zulpich germany unearthed heavily damaged and destroyed late roman fortification works damage includes 0 17 m wide tensile cracks in a 3 1 m wide wall tilted walls and fortification towers horizontal displacement of wall sections of 0 95 m and rotation of wall fragments engineering seismological models are used to test the hypothesis that the observed building damage is of seismogenic nature the site is located at the western edge of the lower rhine embayment lre in the northern part of the rhine rift valley more than 20 damaging earthquakes occurred in the area over the past 300 years several paleoseismic events with magnitudes of at least 6 4 occurred during the holocene site specific strong motion seismograms are modeled for assumed large earthquakes at active faults in the lre using stochastic methods and calibrated q models and duration models nonlinear site amplification is calculated based on an s velocity model from refraction seismic experiments and downhole measurements finite element simulation of the dynamic behavior of a fortification tower shows a natural period of the soil building system of about 3 0 sec horizontal and vertical displacements at the top of the 8 m tall tower reached 0 12 m and 0 06 m respectively for the simulated event no indications of man made activity exist that could explain the damage running water can also be excluded as a threat to the buildings due to the orographic situation and slow acting gravitational causes can be excluded due to the damage structure the destruction and damage is regarded as most probably seismogenic and site intensity is assessed at ix on the european macroseismic scale ems98 grunthal 1998 this result marks the first time an intensity above viii is described for a tectonic earthquake in germany preliminary dating results from three carbon 14 14c accelerator mass spectometry ams samples lead to the second half of the fourth century a d

palaeoseismic studies in greece a review abstract there are numerous reports of ancient human constructions i offset and destroyed by seismic surface faulting or ii with small displacements along horizontal discontinuities testifying to high acceleration effects or iii containing destruction layers below which skeletons of people killed and buried by fallen debris have been found in these cases destructions can safely be assigned to earthquakes that can be dated with stylistic archaeological techniques in coastal areas on the other hand identification of exposed species of the sublittoral zone that have escaped erosion in the mid littoral or supralittoral zones testify to quick probably co seismic uplifts which can be dated with conventional or ams radiometric techniques the amplitude of these uplifts is up to 9 m in the hellenic arc and more than 1 m in the aegean back arc basin finally two cases of seismic faulting deduced from auger core study of the holocene stratigraphy are reported identification of such palaeoseismic effects has important implications for estimation of recurrence intervals and maximum magnitude of seismic shocks in study areas

holocene emergence in euboea island greece abstract detailed mapping along the northwestern coastline of euboea has provided new evidence of colonization by lithophaga lithophaga l reaching about 3 8 m above the present biological msl such marine biological marks together with morphological notches correspond to the occurrence of two sequences of holocene vertical displacements higher than those reported by previous studies on the central part of the southern coast and along the northern coast of the island a well developed emerged notch is found at 1 7 0 1 m above present mean sea level whereas the uppermost part of the lithophagid holes suggest a former emerged shoreline at least at 3 8 0 1 m radiocarbon ams dating of lithophaga shells found in their burrows showed that the lower uplifted shoreline corresponds to a tectonic event probably coseismic apparently dated at 2200 a bp while the higher shoreline corresponds to an older relative sea level transgression possibly of tectonic origin apparently dated about 5570 a bp the apparent radiocarbon age of lithophagid shells can be about 350 to 400 years older than the uplift event that exposed them due to incorporation of host rock carbon nevertheless the two new paleoshorelines provide evidence that repeated uplift movements greater than those reported by previous authors occurred during the late holocene uplifting the western part of the island

a standard analytic curve of potential temperature versus salinity for the western north atlantic abstract an algorithm is described for computing salinity as a continuous function of potential temperature for the western north atlantic the algorithm uses historical data compiled by worthington and melcalf 1961 for the deep western north atlantic and iselin 1936 for shallow and intermediate waters of the same region

fluvial versus tectonic controls on the late holocene geomorphic and sedimentary evolution of a small mediterranean fan delta system abstractthis note examines the relative role of fluvial and tectonic controls in the sedimentary and geomorphic evolution of the asopos delta a small active fault bounded mediterranean fan delta system in eastern attica greece over the late holocene a period of quasi static sea level despite the location of the delta in the hanging wall of a major normal fault system that ruptured in a magnitude 6 0 richter scale event in 1938 and the reporting of significant local effects including tectonic subsidence in contemporary accounts of the earthquake there is little evidence from sediment core analysis and archival data of any significant longer term effect of the 1938 event on sedimentation processes and geomorphology in the fan delta an earlier phase pre thirteenth century ad of channel migration and subsequent progradation in the western part of the delta is likely to have been fluvially rather than tectonically controlled recent rates of vertical sediment accumulation in the delta area a

vernal circulation in the gulf of maine the circulation in the gulf of maine has an important baroclinic component it appears to be driven mostly by the density contrast between high salinity slope water which enters from the atlantic and fresher waters which are formed in the gulf or which enter from the scotian shelf hydrographie surveys in three successive spring seasons suggest that slope water accumulates in georges basin driving a counterclockwise surface circulation which brings scotian shelf water westward into the gulf and contributes to the eastward jet along the inner edge of georges bank the slope water also crosses a sill and enters jordan basin where it provides a potential energy source which may enhance a counterclockwise gyre partly driven by nearshore buoyancy sources and perhaps the wind the coastal limb of the gyre turns offshore east of penobscot bay part of the separated coastal current recirculates in jordan basin and part of it continues into wilkinson basin generating a clockwise eddy as it passes over jeffreys bank there is little evidence for recirculating surface flow in wilkinson basin instead the surface water appears to split into branches feeding the jordan basin gyre the georges bank jet and an export path to nantucket shoals the jordan and georges branches seem to be divided by the denser slope water in georges basin and this may be the central process controlling the vernal intensification of the circulation in the gulf a more complete dynamical understanding awaits models which include the baroclinic influence of boundary waters

late holocene shoreline changes related to palaeoseismic events in the ionian islands greece a systematic multidisciplinary survey on the coasts of the ionian islands founded on 26 new radiocarbon accelerator mass spectrography ams dates has revealed the occurrence of sectors which were uplifted seismo tectonically during the late holocene in corfu two uplift movements of about 0 8m each took place in the central part of the island one of them around 790 400 cal bc and also at a more recent undetermined date in levkas up and down tectonic movements of metric order governed late holocene relative sea level changes at least in the northern part of the island submergence of at least 2 5 m occurred since 2400 years ago with a possible spasmodic subsidence around cal ad 500 700 in cephalonia two vertical displacements affected most of the island around cal ad 350 710 and in ad 1953 both movements resulted in uplift in the southeastern part of the island submergence seems to predominate round ithaca lastly in zante clear evidence of a holocene crustal block movement is limited

holocene tectonic uplift deduced from elevated shorelines eastern coastal range of taiwan abstract this paper is concerned with the tectonic trends that can be deduced from the holocene raised shorelines between ch eng kung and hsin she along a 65 km long coastal sector in the eastern coastal range of taiwan sequences of up to eight superimposed shorelines have been identified in a single section twelve new radiocarbon dates six of which were obtained by accelerator mass spectrometry of in situ marine samples up to 40 m in altitude have confirmed a holocene age however it is difficult to define clearly the upper marine boundary in the highest holocene coastal terraces which have been uplifted to 65 70 m but have been capped by and often also interfingered with alluvial deposits high uplift rates ranging from 2 5 3 0 to over 8 mm yr have been inferred along the coast providing evidence of differential uplift in some cases uplift movements appear to have occurred by steps probably spasmodically recurrence periods of fast uplifts seem to be of the order of at most 1000 yr this means that a new spasmodic movement may be imminent because the last displacement 4 6 m has been dated about 1000 yr bp

the geometrical evolution of normal fault systems abstract the purpose of this paper is to examine the kinematic behaviour of normal fault systems and see what general conditions govern their geometrical evolution we pay particular attention to seismological and surface data from regions of present day active normal faulting as the instantaneous three dimensional geometry at the time of fault movement is better known in active regions than in areas where the faults are now static most normal faults are concave upward or listric this shape can be produced by geometric constraints either because the faults reactivate curved thrusts or because they must be curved to accommodate rotations another effect which will produce curved faults is the variation of rheology with depth brittle failure at shallow depths produces less fault rotation than does distributed creep in the lower part of the crust an important geometric feature of normal faulting is the uplift of the footwall the amount of such uplift is related not only to the elastic properties of the lithosphere but also to the throw and dip of the fault a striking feature of active normal faults is that they occur in groups in which all the faults dip in the same direction this behaviour arises because the faults cannot intersect if they do one must cease to be active the rotation which such fault systems produce reduces the dip of the faults until a new steeply dipping fault is formed once a new fault cuts pre existing faults the earlier faults become locked and a new set of faults must propagate rapidly across the whole region involved many of these geometric constraints also apply to thrust faulting

fault parameters of the 1980 mw 6 5 volos central greece earthquake from inversion of repeated leveling data the 1980 volos almyros seismic sequence the last of an unusual clustering of earthquakes with surface magnitude 6 0 7 0 which hit thessaly central greece between 1930 and 1980 is among the least studied recent earthquakes in greece repeated measurement of three first order spirit leveling traverses crossing the meizoseismal area of the seismic sequence indicates that between 1970 1971 and 1988 1989 a subsidence of about 35 cm is observed at the almyros neogene quaternary graben the observed displacements are significant against random and systematic errors and can be assigned to the 1980 earthquake sequence inversion of leveling data using an elastic dislocation model constrained by structural and seis mological data indicates that the mainshock mw 6 5 and the largest aftershock mw 6 1 were probably associated with reactivation of two subparallel homothetic nor mal faults marking the northern margin of the almyros neogene quaternary graben

quaternary uplift and tilting of amorgos island southern aegean and the 1956 earthquake uplifted pleistocene marine sediments submerged ancient ruins and raised beaches confirm earlier views that the asymmetry of the relief of amorgos island southern aegean testifies to a fault bounded block uplifted and tilted along a sw ne trending horizontal axis the uplifted coast corresponds to a high gradient slope controlled by an oblique master normal fault furthermore geomorphic and biological evidence radiometric data and comparison of aerial photographs indicates that the 1956 earthquake ms 7 4 uplifted the footwall of this normal fault by about 30 cm

the uplifted terraces of the arkitsa region nw evoikos gulf greece a result of combined tectonic and volcanic processes abstractthe arkitsa kamena vourla area of central greece occupies a zone of accommodation between the two tectonic provinces of the north aegean trough the extension of the north anatolian fault system and the gulf of corinth and is characterized by a series of very prominent tectonic landforms notably the large ca 1000 m elevation footwall ridge of the arkitsa kamena vourla fault system despite the highly prominent nature of this footwall ridge and the presence of very fresh tectonic landforms this fault system is not known to have hosted any major historical earthquakes and the tectonic and geomorphic evolution of the arkitsa kamena vourla area remains poorly constrained this article utilizes a combined geomorphological sedimentological and macro microfossil approach to evaluate the late quaternary evolution of the arkitsa area in the eastern part of the fault system focusing on prominent uplifted terraces present in the hanging wall of the arkitsa fault three distinct raised glaciolacus

kinematics and deformation of central and southwestern greece from historical triangulation data and implications for the active tectonics of the aegean abstract changes in the coordinates of 38 stations 32 of which were common to three historical triangulation surveys 1889 1905 1927 1930 and 1950 1970 in central greece were computed based on conventional adjustment techniques and the assumption of a nearly fixed baseline length some of the calculated coordinate changes are significant against the a posteriori network adjustment errors and are likely to indicate tectonic motions consistent with those deduced from geological and geophysical data and other geodetic studies comparison of the first survey network with gps data more explicitly the historical geodetic data confirm the rotational character of the deformation in the area but they show that the strain pattern is likely to have changed after 1930 between 1890 and 1930 strain was changing smoothly as if no strain discontinuities existed while the peloponnesus was under contraction from the northeast probably reflecting accommodation of strain from the arc significant left lateral shear in the gulf of corinth and n s extension in the whole of the study area were observed only after 1930 estimates of strain are consistent with those deduced from comparison of historical triangulation and gps data corrected for the scale error that exists in the terrestrial geodetic data in greece and estimates of strain from seismological data the change in the kinematic pattern after 1930 seems to be confirmed by changes in the shear strain computed directly from changes in observed angles between stations and from changes in the seismicity rates such changes although not unusual in the geological record are not easy to explain but may reflect elastic rebound effects in area with an extremely complicated tectonic fabric or hysteresis in the accommodation of e w compression from the arc by n s stretching

the 1953 earthquake in cephalonia western hellenic arc coastal uplift and halotectonic faulting summary geomorphological marine biological and radiometric data in combination with earlier reports reveal that the m 7 2 1953 cephalonia earthquake the most destructive but least studied earthquake in greece this century was associated with a 0 3 0 7m quasi rigid body uplift and westward tilting of the central part of the island another palaeoseismic event around 1500 yr bp associated with coastal uplifts was also identified structural data indicate that the 1953 uplift is bounded by two subparallel east dipping major reverse faults and corresponds to a piston like motion this structurally unusual pattern of seismic deformation is detached from the deformation of the basement conspicuously a thrust and different from the long term deformation pattern of the area it is probably due to the particularities of salt tectonics a 1500m thick salt layer acts as a regional dccollement while thinner layers are sandwiched between the carbonate thrust sheets that compose the overburden and reduce their friction during fault movement this crustal anisotropy is responsible for the observed anomalous attenuation of seismic waves during the 1953 and historical earthquakes the 1953 seismic surface deformation mimics long term halotectonic patterns but is not directly indicative of the regional stress field for it reflects uplift induced stresses only

holocene coastal notches in the mediterranean region indicators of palaeoseismic clustering abstract marine tidal notches are developed by bioerosion in the intertidal zones of rocky coasts but a combination of sea level change and crustal movements can result in them being raised above or submerged below the water line for that reason the present day elevation of these former shorelines relative to the mean sea level has long been used to quantify relative coastal uplift and subsidence in tectonically active areas assuming that the sea level eustatic change component is known along the microtidal mediterranean littoral it is generally assumed that notches develop during relative stillstands of sea level when tectonic and eustatic trends are in unison and that discrete notch levels record abrupt shoreline changes caused by local seismic displacements recently however a climatic model for notch formation has been proposed in which stable periods of holocene climate favour enhanced erosion in this competing model the rate of sea level rise is lower than the tectonic uplift rate and individual notches are not specific seismic indicators because marine notches are widely used as geomorphic markers of tectonic and in some cases palaeoseismic movements a reappraisal of the geological significance of these strandlines is warranted in this paper we explore the two conflicting notch models using a database of eastern mediterranean palaeoshorelines although we conclude that the spatial and temporal distribution of the notches supports a dominantly tectonic control on notch genesis as a result of earthquake clustering we highlight how the diachronous timing of notch development tempers their value as tectonic markers

historical coseismic uplift on euboea island greece abstract in the aegean region it is usually accepted that uplift is confined to the southern areas near the outer island arc whereas subsidence prevails in the inner basin areas however we give evidence of elevated notches andlithophaga shells dated by ams14c showing that holocene coseismic uplift of the order of about a metre occurred in inner aegean areas too and affected parts of the coasts of north and central euboea island between 510 and 380 b c and also possibly between 1050 and 900 b c

marine bioerosion in rocks of the prehistoric tholos of la pastora valencina de la concepcion seville spain archaeological and palaeoenvironmental implications in this study we examined the materials used in the building of the tholos of la pastora located in the archaeological site of valencina de la concepcion seville spain which represents the largest settlement of the guadalquivir valley during the third millennium bc three different types of rock were found palaeozoic sandstone shale which forms the walls of both the corridor and the chamber palaeozoic granite which makes up part of the roof slabs and neogene calcareous sandstone which forms the remainder of the roof and floor slabs as well as the jambs lintels and some blocks of the walls of the chamber intense marine bioerosion as a result of the activity of bivalves annelids and sponges was observed in some elements of the calcareous sandstone in fact the remains of some of the tracemakers were unusually well preserved as was the case for the bivalve petricola lithophaga whose shells remain in many of their burrows we infer that these bioerosion structures were formed in a shallow coastal environment intertidal and that bioerosion was possible until the few moments before its extraction as construction material thereby the environment in which rock extraction took place was likely a coastal wave cut platform in which calcareous sandstone levels outcropped and stood out between clay layers the radiocarbon dates obtained from these bivalve shells provide a time range between 4780 and 4400 cal yr bp 2830 2450 yr bc as the highest probability for rock extraction and the subsequent building of the tholos thus the date represents a terminus post quem for the construction of the monument of la pastora

holocene coastal deformation in simeulue and nias indonesia west of sumatra indonesia the islands of nias and simeulue as well as their smaller neighbours display elevated coral reefs and abandoned intertidal platforms faunas from three sections indicate a late cainozoic age for the reefs unaltered mollusc shells from nineteen fossil platforms were dated by first order 14c analysis the localities sampled were 0 5 to 3 5 m above normal high tide apart from one non finite result the ages ranged between modern 300 yrs and 5800 300 yrs b p the resulting average uplift rates are 0 3 1 0 mm yr no simple relationship between sample age and height is apparent but the bulk of the ages fall within three periods 0 800 yrs b p 2000 3400 yrs b p and 4500 5800 yrs b p suggesting that episodes of uplift were separated by periods of quiescence and that they were seismic in origin the pattern of deposition at the key section on nias supports this inference evidence of recent subsidence in eastern simeulue shows that uplift was locally accompanied by tilting the pattern and rate of movement are consistent with the position of the islands on the outer arc ridge of the sunda arc and with the long term uplift rates derived from palaeontological sources the inverse darwin coral reef model proposed here for the development of reefs on the flanks of rising neogene cores may also be applicable elsewhere

the terraces of corinth gerrce a detailed record of eustatic sea level variations during the last 500 000 years abstract between corinth and xylokastro 20 marine terraces reflect the interaction of the northern peloponnese uplift and the global eustatic sea level fluctuations during the last 500 000 years correlation of the terraces with oxygen isotope records in deep sea cores allowed accurate dating of these fossilized transgressive shorelines curves of altitude versus age have been plotted they show a regular decrease of the uplift rate and a frequent return of the sea level very close to the present day one not only during the interglacial periods 5 7 9 11 13 but also during glacial periods 3 1 3 3 6 8 the alternative would be to suppose very complicated and highly improbable vertical movements of the substratum to explain the regularity of the curves the rhythm of these high sea levels is around 20 30 ka since at least 330 000 years ago

evidence of mis 5 sea level highstands in gebel mousa coast strait of gibraltar north of africa abstract the last interglacial is considered the most suitable episode from which to infer patterns of rapid sea level change since its climatic conditions were similar to those of the present interglacial however specifying the true position of its sea level with high accuracy is very troublesome in the absence of sedimentological erosional or even palaeontological markers this study investigates the morphosedimentary evidence beach deposits cliff notch and shore platform of two highstands registered and dated during mis 5 stage by u series dating in the north of morocco strait of gibraltar bioerosive notches and mixed siliciclastic and carbonate deposits high energy beaches with algal bioherms were formed in coastal environments during mis 5a a sea level height of 10 m asl can be inferred for this substage the record of mis 5e substage is less defined in the geomorphological record consisting of backshore foreshore deposits located at 13 to 15 m asl a tectonic uplift rate of 0 1 mm yr has been estimated for the last 130 kyr these data are consistent with models of coastal uplifting calculated for the strait of gibraltar

an optical study of the water masses of the gulf of maine optical studies of the suspended load in the gulf of maine have been performed in conjunction with hydrographic and biological analyses between late winter and early fall major particle sources are coastal runoff benthic resuspension and biological activity analysis of the optical efficiencies of the particles suggests that runoff and resuspension sources are restricted to the nearshore and shallow regions the variabilities in the coupling and discoupling of the optical and hydrographic features of the gulf demonstrate that advection is primarily responsible for the distribution of clear water masses while settling vertical mixing and productivity are the processes behind the distribution of particles

coastal elevation changes in eastern sicily implications for volcano instability at mount etna the eastern flank of mount etna sicily has been recognised as being unstable and three contrasting models have been proposed to account for this phenomenon these being deep seated spreading shallow sliding and tectonic block movements these models are examined by making reference to the rates and patterns of crustal movement along the eastern coastline of sicily as determined from palaeoshoreline data the south eastern coastline of sicily portopalo to catania provides no evidence of holocene emergence in contrast the volcanic coastline catania to capo schiso and the northeastern shoreline taormina to milazzo display widespread evidence of coastal emergence radiocarbon dated remains indicate that both the volcano and northeastern sicily have been uplifted at a rate exceeding 1 5mm yr during holocene times although more recent rates of uplift may have been greater the pattern of uplift suggests that the northeastern coastline of sicily including the volcanic ediface is apparently uplifting as a coherent unit with superficial flank movements being superimposed on a regionally uplifting sub volcanic basement

influence of diurnal heating on stratification and residual circulation of georges bank 1 the influence of the diurnal heat flux on summer stratification and residual circulation over georges bank was examined using a three dimensional primitive equation numerical circulation model for a given spatially uniform and time varying heat flux the model results show that the surface water is heated much faster on the southern flank than on the northern flank and much faster in the stratified region than in the mixed region heating significantly strengthens the tidal mixing front and intensifies the frontward convergence near the surface as seasonal stratification develops the location of the tidal mixing front gradually shifts on bank on the southern flank while remaining almost unchanged on the northern flank response of the tidal currents to the diurnal variation in the heat flux varies across georges bank it changes periodically with tidal cycles on the southern flank but is locked to the phase of the eastward tidal current on the northern flank this phase lock feature directly contributes to the intensification of the along bank residual current jet on the northern flank diagnostic analysis suggests that this intensification is mainly caused by the heat enhanced cross bank momentum flux modelcomputed variations of near surface temperature and residual currents are in good agreement with satellite derived sea surface temperature data and drifter measurements index terms 4219 oceanography general continental shelf processes 4227 oceanography general diurnal seasonal and annual cycles 4255 oceanography general numerical modeling 4279 oceanography general upwelling and convergences 4528 oceanography physical fronts and jets keywords heat flux tidal mixing front residual current stratification frontward convergence

late pleistocene and holocene sea level change in greece and south western turkey a separation of eustatic isostatic and tectonic contributions summary sea level change during late pleistocene and holocene times is a combination of eustatic isostatic and tectonic contributions in the central mediterranean sea region of greece and western turkey the isostatic components are important due to the changing gravitational potential of the earth the readjustment of the crust upon the removal of the large ice sheets and the addition of the meltwater into the oceans including the mediterranean changes in relative sea level due to these glacio hydro isostatic adjustments have reached amplitudes of 1 mm yr 1 during the last few thousand years a model for the isostatic contribution to sea level change including the movement of shorelines due to the combined eustatic isostatic changes is developed based on earth model and ice sheet parameters estimated from sea level observations from other areas comparisons of this model with observations of sea level change permit rates of vertical movement to be estimated for late holocene time allowance for the isostatic factors makes a significant difference to these rates the plains of argolis lakonia messinia and navarine in the southern peloponnese for example appear to be tectonically stable on time scales of a few thousand years and longer consistent with the position of the last interglacial shoreline close to the present day sea level the observations here of a rising sea level are largely the consequence of the glacio hydro isostasy and not of a long term tectonic process crete as a whole is subject to tectonic uplift but at variable rates and forms part of an arcuate zone of uplift extending from rhodes and karpathos in the east to kithera in the west at rates that locally exceed 4 mm yr 1 the southern shore of the gulf of corinthos is also subject to uplift at rates approaching 1 5 mm yr 1 these isostatically corrected estimates for the past few thousand years are in agreement with longer term estimates based on the position of the last interglacial shoreline only on the perachora peninsula do the tectonic rates over these two time intervals appear to be in disagreement with the late holocene rates being much higher than the long term rates

reefal sediments of al ghardaqa northern red sea egypt abstract reefal sediments are abundant along the red sea samples of such sediments were studied in the al ghardaqa area along the red sea coast of egypt twenty samples were collected from the beach intertidal zone and lagoon in the study area geochemical analyses were carried out by atomic absorption spectrophotometer and flamephotometer while mineralogical compositions of the sediments were studied by x ray diffraction the average concentrations of the different chemical constituents were as follows sio 2 21 4 al 2 o 3 8 5 tio 2 0 12 fe 2 o 3 0 38 mno 0 021 cao 21 7 mgo 5 01 sro 0 82 na 2 o 0 23 k 2 o 0 11 zn 31 ppm and cu 21 ppm the chemical constituents are categorized into four groups regarding their possible sources aragonite and high mg calcite are the major carbonate minerals characterizing the reefal sediments on the other hand quartz and feldspar are the common minerals of terrigenous origin

episodic tectonic subsidence of late holocene salt marshes northern oregon central cascadia margin salt marsh subsurface deposits 0 4 m depth in netarts bay a small coastal lagoon of northern oregon record six events of marsh burial in the last several thousand years five of the buried marsh surfaces show sharp nonerosional upper contacts with either anomalous sand layers tsunami deposits or tidal flat mud deposits these sequences indicate episodic abrupt subsidence of the marsh surfaces to low intertidal levels in contrast lower marsh contacts with underlying intertidal muds are gradational indicating gradual uplift and development of the marsh three independent measures of deposit elevation relative to mean tidal level percent organics diatom assemblages and percent eolian sand have been used to estimate vertical displacements of marsh surfaces abrupt subsidence displacements of 1 1 5 m alternate with gradual uplift displacements of the order of 0 5 1 0 m the vertical tectonic movements are interpreted to reflect coseismic strain release abrupt subsidence following interseismic strain accumulation gradual uplift associated with interplate coupling between the juan de fuca plate and the north american plate in the cascadia subduction zone recurrence intervals between subsidence events range from possibly less than 300 years to at least 1000 years with the last dated event likely occurring 300 400 radiocarbon years before present rcybp significant 14c age overlaps of at least four subsidence events recorded at netarts and reported for southern washington and other northern oregon bays at 300 500 1000 1300 1400 1800 and 3000 3300 rcybp suggest the potential for event synchroneity over at least 200 km of the central part of the cascadia subduction zone additional work is needed to test the synchroneity of these episodic events of coseismic subsidence

seismicity and associated strain of central greece between 1890 and 1988 summary we examined the seismicity of central greece between 1890 and 1988 using macroseismic and instrumental data to ask two questions 1 does the seismicity of this period reveal all the major tectonic structures that are known to be active and 2 what are the likely strains associated with the seismicity over this period many known active structures have been effectively aseismic for the last hundred years and even the inclusion of all known large events earlier than 1890 reveals no activity associated with the ne coast of evia gulf of argos or graben ne of mt parnassos it is clear that even 100 years data are inadequate for either a reasonable assessment of seismic risk or for a confident estimation of maximum magnitude however we are aware of no earthquakes in central greece during the last 200 yr that were larger than ms 7 0 it is probable that the maximum magnitude is restricted by the maximum length of fault segments which appears to be around 15 20 km the earthquakes of ms 5 8 during 1890 1988 can account for a n s displacement of around 45 70 cm with maximum and minimum estimates a factor of two greater and smaller than this across part of a 1890 1900 triangulation network in central greece that was resurveyed in 1988 the contribution of smaller events may increase this displacement by about 50 per cent this cumulative seismic displacement is similar to that estimated from the geodetic work about 100 cm but a detailed comparison of the two sets of observations will be reported elsewhere a re evaluation of all the important earthquakes of 1890 1988 in central greece is presented in the appendix which summarizes information of use to both earth scientists and engineers

smooth or oscillating late holocene sea level curve evidence from the palaeo zoology of fixed biological indicators in east australia and beyond abstract the nature of late holocene sea level change has important palaeo environmental implications for the understanding of past and present coastal oceanic and climatic systems this study develops a fixed biological indicator fbi method based on tubeworm barnacle assemblages in order to construct a late holocene sea level curve for south east australia it also compares changes within and between mid latitude regions of the southern hemisphere using the palaeo biology of inter tidal sub fossils that have provided time elevation data covering the past 5000 years five sites from around the mouth of the port hacking estuary 29 km south of sydney are described in detail the results suggest that rather than relative sea level describing a stable or smoothly falling pattern from a maximum of 1 0 m above present over the last 5000 years on the southeast australian coast there have been complex movements from a maximum of over 1 5 m with at least one marked fall between 3500 and 3400 yr bp and the possibility of a small positive oscillation around 1900 yr bp furthermore changes in the inter tidal species at our sites suggest that there was a period between 4300 and 2800 years where ocean temperatures were warmer than present our port hacking findings are compared with other studies from the east coast of australia as well as the pacific islands and brazil evidence from each location suggests a broad similarity in the timing of environmental events and marine fluctuations across an expanse of the southern hemisphere are such similarities coincidental or part of mechanisms common to mid latitude southern hemisphere regions

tell formation processes as indicated from geoarchaeological and geochemical investigations at xeropolis euboea greece abstract xeropolis is a tell site on the island of euboea greece just to the east of the village of lefkandi and was occupied from the early bronze age to the early iron age excavations in recent years have provided an opportunity to investigate site formation processes using geoarchaeological and geochemical techniques sediments derived from the tell on the southern side have been lost by coastal erosion whilst those on the north mantle the flanking slope of particular interest is a homogeneous and unstratified deposit of over 2 m which overlies the archaeology near the southern perimeter of the summit area the soil structure as evident in thin sections indicates a high degree of bioturbation probably stimulated by recent manuring and cultivation the implication is that tillage erosion has had a major impact on the morphology as well as on the surface soils of the tell despite such reworking and redeposition of near surface materials it is still possible from multi element analysis to identify the geochemical distinctiveness of six archaeological contexts pit house plaster floor alley road and yard pits and floors have high loadings of all elements except pb in contrast pits and floors have the lowest elemental concentrations

episodic uplift deduced from holocene shorelines in the perachora peninsula corinth area greece four raised shorelines between 1 1 m and 3 5 m have been identified at two localities on the perachora peninsula and were dated by ams 14c to between 6400 and 1500 calibrated years ago uplift movements seem to have occurred in increments of 0 8 0 3 m with a return period of about 1600 years the last uplift coincided with a regional tectonic paroxysm which has already been documented in several areas of the eastern mediterranean the average uplift rate was probably faster during the holocene than the average since the last interglacial period no important vertical displacement occurred in this area at the time of or after the 1981 earthquake but a new episode of coseismic uplift may be in preparation

the steady state barotropic response of the gulf of maine and adjacent regions to surface wind stress abstract the response of the gulf of maine region to steady spatially uniform wind stress is examined using a linearized numerical model with the influence of the strong tidal currents in the region included in the bottom stress formulation the sensitivity of the model results to various idealizations is investigated including the assumption of linearity the bottom steam formulation cross shelf structure in the large scale alongshelf wind stress and the cross shelf boundary conditions the model solutions for the gulf are found to be sensitive to the backward boundary condition on the scotian shelf but not to the forward boundary condition in the middle atlantic bight for alongshelf stress the former is estimated using csanady s arrested topographic wave model and observed coastal sea level gains at halifax the model has a spinup time of about one day comparable to previous estimates for the region the alongshelf component of wind stress is generally much more effective than the cross s

currents at lindenkohl sill in the southern gulf of maine from june 22 to september 3 1986 current speeds and directions were measured at depths of 76 127 and 212 m over lindenkohl sill 225 m which controls an important deepwater spreading path from georges basin into wilkinson basin in the gulf of maine most 70 of the low frequency subtidal variability occurred in a barotropiclike mode in which the inward currents were coherent with alongshore wind stress for 5 day periods early in the record and for 3 day periods late in the record the coherence weakened during the central part of the record when dense atlantic slope water from georges basin moved over the mooring site most of the remaining variance appeared in a baroclinic mode that added constructively to produce surprisingly large 1 m s 1 near bottom currents during the wind coherent intervals at other times the modes interfered to produce near zero currents over the sill while middepth and upper level currents were intensified the relationship between the wind stress and the currents suggests the action of a density modulated coastal upwelling mechanism in which the deep inward currents over the sill respond directly to northeastward alongshore wind stress at times of weak stratification increased density stratification caused by water mass adjustments or seasonal heating produces a more complex baroclinic response it is suggested that the springtime onset of northeastward winds over the gulf of maine may play an indirect but important role in the yearly intensification of the baroclinic circulation in the gulf by controlling or modulating the indraft of slope water into the inner basins

geological and geomorphological evidence of recent coastal uplift along a major hellenic normal fault system the kamena vourla fault zone nw evoikos gulf greece the active normal faulting region of central greece has been the focus of intense study due to its relatively high rates of tectonic deformation and the frequent occurrence of damaging moderate magnitude earthquakes the structure of central greece is dominated by a series of roughly wnw ese trending extensional faults which have created a series of half grabens the most prominent of which are the gulf of corinth and the evoikos gulf of these two structures the evoikos gulf and particularly its northern part remains poorly understood in terms of its geodynamic structure and tectonic significance here we use exposed coastal sediment sequences and coastal geomorphological indicators to examine the pattern of historical sea level change in the northern evoikos gulf specifically in the hangingwall of the prominent kamena vourla fault system to better constrain recent coastal elevational changes and tectonic activity in this area in particular we describe and analyse a series of exposed coastal sections which contain recent 1 m above contemporary high water level these deposits occur in the hangingwall of the prominent arkitsa normal fault strand and indicate a local uplift rate possibly exceeding 1 mm year significantly greater than long term regional uplift rates the pattern of uplift of these coastal sections is most consistent with recent coseismic uplift on an offshore shore parallel fault strand north of arkitsa

the mean and seasonal circulation off southwest nova scotia abstract long term measurements off southwest nova scotia reveal the following features of the mean circulation a a westward longshore coastal current 4 10 cm s 1 b an anticyclonic gyre around brown bank 5 15 cm s 1 and c an upwelling circulation off cape sable 1 2 cm s 1 at bottom the gyre circulation appears permanent but the coastal current and upwelling exhibit annual variations of the same order as the means there is a distinct annual signal in the longshore transport at cape sable maximum westward in winter whereas the mean transport 0 14 106 m4 s 1 is consistent with both geostrophic estimates and budget requirements in the gulf of marine strong seasonal cycles are also found in the salinity and density fields at cape sable which appear to be controlled both by buoyancy input from the coastal current and local mixing effects a linear diagnostic model indicates that the primary dynamical balance for the circulation is between a longshore pressure gradient and longshore mean

recent observations of the mean circulation on georges bank abstract a clockwise circulation around georges bank was measured by means of moored current meters aircraft tracked surface drifters and satellite tracked drifters drogued at 10 m the strongest flow was in a narrow jetlike current 30 cm s 1 along the northern flank of the bank the flow of shelf water on the southern flank was westward 10 cm s 1 toward the middle atlantic bight some of this water flowed northward through the eastern side of great south channel and recirculated around georges bank the satellite tracked drifters and the moored observations indicate that the circulation around the bank was not completely closed and considerable variability occurs in the trajectory of an individual water particle

comment to the article late quaternary depositional history of the north evvoikos gulf aegean sea greece by van andel t and perissoratis c marine geology 232 157 172 2006

historical and recent evidence of scotian shelf water on southern georges bank abstract historical data from 1912 1987 indicate that low salinity less than 32 0 psu near surface water occurs occasionally on southern georges bank during may while none occurs during april composite monthly plots of historical near surface salinity and estimated advection rates show that the southwestern scotian shelf is the immediate upstream source of this low salinity water optimally interpolated satellite derived sst and hydrographic data reveal that very cold less than 2 0 c low salinity less than 32 0 psu scotian shelf water ssw initially located south of the 200 m isobath off southern georges bank in early march 1992 moved north onto southern georges bank during april 1992 ssw was not as extensive during the same period in 1993 as evidence by significantly higher temperatures and salinities these differences show large interannual variability in the transport and or properties of ssw flowing onto georges bank lower higher salinities measured during spring 1992 1993 on southern georges bank are consistent with higher lower st lawrence river discharge noted during spring 1991 1992 and the nine month lag between annual discharge maxima from rivers located upstream and minimum salinity at cape sable in february however comparisons between historical occurrences of low salinity less than 32 0 psu ssw on southern georges bank noted for may 1966 1971 and 1978 and cumulative st lawrence river discharge from the spring prior to each occurrence show no relationship this suggests that the occurrence of low salinity water on southern georges bank is not directly related to variations in upstream river discharge although an idealized model of wind forcing on a bank trapped density front shows that near surface flow is related to superposition of an ekman layer and the along bank gyral circulation evidence from late winter spring 1992 and 1993 on georges bank shows that except for on bank movement of the shelf slope front during late spring 1992 simple ekman theory does not explain on bank movement of the ssw plume during 1992 nor the immobile nature of the shelf slope front during late winter 1992 and late winter spring 1993 surface heat flux and satellite derived sst from georges bank and the scotian shelf together with a slab mixed layer model allows estimation of the advective heat flux and transport of ssw flowing onto georges bank from the scotian shelf during late winter spring 1992 mean advective heat flux onto georges bank during march may 1992 is 14 5 mw cm 2 with an estimated error of 3 5 mw cm 2 demonstrating that advection of cold ssw onto georges bank is required mean velocity and transport of ssw flowing onto georges bank during march may 1992 are 13 4 cm s 1 and 0 21 sv assuming a ssw depth width of 40 m 40 km demonstrating that flow of ssw onto georges bank was robust during the period at this time the dynamics that control the flow of ssw across northeast channel are unknown