earthquake generated tsunamis in the mediterranean sea scenarios of potential threats to southern italy italian civil defense project development of new technologies for the protection of the italian territory from natural hazards funded by the italian ministry of university and research

state of stress in the southern tyrrhenian subduction zone from fault plane solutions summary in this paper we present revised locations and original focal mechanisms computed for intermediate and deep earthquakes that occurred within the southern tyrrhenian subduction zone between 1988 and 1994 in order to improve our knowledge of the state of stress for this compressional margin in particular we define the stress distribution within a large portion of the descending slab between 40 and about 450 km depth the seismicity distribution reveals a continuous 40 50 km thick slab that abruptly increases its dip from subhorizontal in the ionian sea to a constant 70 dip in the tyrrhenian we computed focal mechanisms for events with magnitudes ranging from 2 7 and 5 7 obtaining the distribution of p and t axes for many events for which centroid moment tensor cmt solutions are not available thus enabling the sampling of a larger depth range compared to previous studies we define three portions of the slab characterized by different distributions of p and t axes a general down dip compression is found between 165 and 370 km depth whereas in the upper part of the slab 40 165 km depth the fault plane solutions are strongly heterogeneous below 370 km the p axes of the few deep events located further to the north have a shallower dip and are not aligned with the 70 dipping slab possibly suggesting that they belong to a separated piece of subducted lithosphere there is a good correspondence between the depth range in which the p axes plunge closer to the slab dip 70 and the interval characterized by the highest seismic energy release 190 370 km

spatial variation in stresses in peninsular italy and sicily from background seismicity abstract we have retrieved the stress tensor orientation in the italian region applying the fmsi technique gephart j 1990b fmsi a fortran program for inverting fault slickenside and earthquake focal mechanism data to obtain the regional stress tensor comput geosci 16 953 989 to fault plane solutions of 298 small earthquakes 2 5 m d istituto nazionale di geofisica in the period 1988 1995 first we verified that the stress inversion procedure generally applied to a large number of focal mechanisms of earthquakes recorded in a local seismic network could be successfully used in italy using background seismicity recorded over large 100 200 km regions then comparing the stress inversion results with other stress indicators we find that they are geologically sound for many regions in italy even if the misfit values are relatively large we also find that the largest misfit values are determined by a few earthquakes only 10 20 of the total number excluding these earthquakes from inversion the average misfit becomes much lower by 30 40 the results obtained in this study confirm the large variations of the stress field over a relatively short distance in italy but also confirm the existence of regions extending for a few hundred kilometres within which the stress is homogeneous among these most of the apennines are dominated by extension perpendicular to the trend of the mountain belt only in the northern apennines is there any clear distinction between an area of extension in the inner portion of the belt and an area under horizontal compression along the adriatic margin of the belt more rapid variations occur around calabria and sicily as expected because of the complexities linked with the tyrrhenian subduction and with active volcanism in the ionian calabrian coastal region there are hints of active nw se compression although constrained by a few data whereas in the messina strait we observe e w extension and a vertical 1 in northern and western sicily our results indicate n s to nw se compression roughly consistent with the general convergence between the european and the african plates

a revision of the 1693 eastern sicily earthquake and tsunami the 1693 earthquake was a disastrous event affecting eastern sicily southern italy where it caused over 60 000 victims and total destruction of several villages and towns in the districts of siracusa ragusa and catania the earthquake was followed by a tsunami that struck the ionian coasts of sicily and the messina strait and was probably observed even in the aeolian islands historical documents on sea waves and flooding though not abundant allow us to form a picture of the tsunami first attack and inundation the first water movement all along the sicilian coastline was a strong sea withdrawal followed by a violent sea return and coastal flooding the main purpose of this research is to put constraints on the focal mechanism of this earthquake on the basis of the available documents on the tsunami 1 by simulating tsunami from different possible sources via numerical modeling based on finite element technique and shallow water approximation and 2 by choosing the source best fitting the tsunami data as the most plausible cause for this tsunami the relevance of this study should also be evaluated in light of the circumstance that no certain indication on the earthquake fault can be deduced from the available macroseismic data alone solving the source problem for this event one of the largest occurring in southeastern sicily in historical times is a significant contribution to understanding the seismotectonic regime of the region and to assessing the related earthquake and tsunami hazard risk with implications on mitigation policies

an early paleoproterozoic high k intrusive complex in southwestern tarim block nw china age geochemistry and tectonic implications abstract systematic geochronologic geochemical and nd isotopic analyses were carried out for an early paleoproterozoic high k intrusive complex exposed in southwestern tarim nw china the results provide a better understanding of the paleoproterozoic tectonic evolution of the tarim block zircon u pb age dating indicates two paleoproterozoic magmatic episodes occurring at ca 2 41 ga and ca 2 34 ga respectively which were followed by a ca 1 9 ga metamorphic event the 2 41 ga granodiorite adamellite suite shares characteristics of late to post orogenic metaluminous a type granites in its high alkalinity na2o k2o 7 6 9 3 total ree 410 788 ppm zr 370 660 ppm and y 21 7 58 4 ppm contents end t values for the suite range from 3 22 to 4 71 and accordingly the nd modal ages t2dm vary between 3 05 ga and 3 17 ga based on geochemical data the 2 34 ga suite can be subdivided into two sub suites namely a type and s type however both types have comparable nd isotope compositions end t 0 41 to 2 08 and similar narrow t2dm ranges 2 76 2 91 ga geochemical and nd isotopic data for the high k intrusive complex in conjunction with the regional geological setting suggest that both the 2 41 ga suite and the 2 34 ga a type sub suite might have been produced by partial melting of the archean mafic crust in a continental rift environment the s type sub suite is thought to have formed by partial melting of felsic pelites and or metagreywackes recycled from archean crust ttg gabbro enclaves with positive end t value 2 15 have been found to be intermingling within the 2 34 ga suite ca 2 34 2 36 ga gabbroic dykes and adamellites have previously been documented in eastern tarim these observations indicate that the high k intrusions may reflect the emergence of depleted mantle upwelling beneath the tarim block at that time we suggest a three stages model for the precambrian crustal evolution in the tarim block 1 the formation of proto crust ttg by ca 2 5 ga 2 episodes of felsic magmatism possibly occurring in continental rift environments at ca 2 41 ga and ca 2 34 2 36 ga and 3 ca 1 9 ga metamorphism that may represent the solidification of the precambrian basement of the tarim block

active faulting and seismicity along the siculo calabrian rift zone southern italy abstract southern italy is dominated by extensional tectonics that in the calabrian arc and eastern sicily produced the development of the siculo calabrian rift zone scrz this zone is represented by a 370 km long fault belt consisting of 10 to 50 km long distinct fault segments which extend both offshore and on land being also responsible of the crustal seismicity of this region the geological and morphological observations indicate that the active normal faults of the scrz are characterized by throw rates ranging from 0 7 to 3 1 mm a they accommodate an almost uniform horizontal extension rate of about 3 0 mm a along a wnw ese regional extension direction based on our field observations and following empirical relationships between magnitude and surface rupture length connections between large crustal earthquakes and distinct fault segments of the scrz have been also tentatively tested our data indicate moreover that the magnitudes m of the historical and instrumental earthquakes are consistent with the estimated values and that the geometry and kinematics of the fault segments and the related different crustal features of the scrz control the different seismic behaviours of adjacent portions of the active rift zone

pattern and rate of post 20 ka vertical tectonic motion around the capo vaticano promontory w calabria italy based on offshore geomorphological indicators abstract the magnitude and rate of late pleistocene holocene vertical tectonic movements offshore of the capo vaticano promontory western calabria southern italy have been measured on the basis of the present day depth variations of the edges of submerged depositional terraces and associated abrasion platforms that formed below the storm wave base during the sea level stillstand of the last glacial maximum lgm these depositional features represented by submerged prograding wedges and an associated terrace shaped upper boundary have been identified in high resolution seismic reflection profiles acquired along the continental shelf and the upper slope of the promontory and are referred to in this study as lowstand infralittoral prograding wedges lipws our new data and methods provide evidence that lipws can be used as geomorphological indicators of vertical movements in offshore settings with well controlled uncertainty removal of the non tectonic component of vertical changes using an ice volume equivalent eustatic sea level compilation indicates 11 3 2 m of uplift and 25 3 2 m of subsidence from southwest to northeast along the promontory over a distance of 22 km during the post lgm the resulting uplift and subsidence rates including both regional and local components for the last 20 350 1 35 years are 0 54 0 2 mm y and 1 23 0 25 mm y respectively these results are consistent with longer term estimates based on uplifted 215 82 ka old coastal terraces and late holocene shorelines this integration of offshore and coastal markers indicates a pattern of vertical movements characterized by a marked asymmetry associated with a northeast down tilt of the capo vaticano promontory the calculated tilt rate increases by one order of magnitude during the post lgm in respect to the time interval from 215 to 82 bp displacement associated with the nw se striking normal fault that bound the capo vaticano promontory to the gioia tauro basin ended in the pleistocene and thus does not contribute to the tilt of the promontory at least during the last 215 ka

the use of scenarios to evaluate the tsunami impact in southern italy this paper outlines the main contributions to the definition and evaluation of tsunami hazard and risk resulting from studies undertaken in italy in recent years and emphasises that adopting characteristic cases or scenarios is a very useful and advantageous technique three main cases are given as valuable examples that is the 1627 gargano tsunami the 1693 eastern sicily tsunami and the 1908 messina straits tsunami since 1 they characterise three distinct tsunamigenic regions 2 they are instances of destructive events and 3 they have been extensively studied in the last decade the paper elucidates the state of the art of the research on these events clarifies the chief points of agreement and disagreement among scientists and illustrates the main issues that are to be addressed by future research to provide reliable assessment of tsunami risk and to implement efficient countermeasures to defend the life of people coastal structures and the coastal environment against the attacks of tsunamis

the 1905 calabria southern italy earthquake hypocenter location causative process and stress changes induced in the area of the 1908 messina straits earthquake

numerical modelling of the september 8 1905 calabrian southern italy tsunami summary this paper presents a study of the tsunami following the disastrous earthquake that occurred on the 8th of september 1905 in calabria southern italy the shock caused devastation in many towns and villages leading to more than 500 victims according to coeval sources the tsunami was not catastrophic but was large enough to inundate low lying lands in several coastal segments and to affect boats no specific study was ever devoted to this tsunami in the literature our analysis is carried out by means of numerical modelling and aims at filling this gap since the source fault of the earthquake has not yet been identified we study three tsunamis produced by likely potential sources according to macroseismic data and the seismotectonic knowledge of the region namely the capo vaticano cv fault the vibo valentia vv fault and the lamezia la fault we compute tsunami waves under the hypotheses that the sea floor deformation is caused by a shear double couple dislocation taking place over a rectangular fault and that sea waves propagate according to the shallow water approximation the three tsunamis cause either a pure initial depression vv and la or a predominant initial depression cv of the sea surface in the gulf of st eufemia one very relevant finding is that tsunami energy is trapped within a narrow channel along the calabrian coast to the north of the source with the consequence that wave amplitudes computed here are much larger than the values expected in the case of an ordinary energy decay law with distance energy trapping along southern coastal segments is less efficient only a small fraction of tsunami energy penetrates the straits of messina to the south propagation to the west is affected by the aeolian islands that produce a quasi shadow zone on the side opposite to the tsunami impact the la tsunami is found to be too weak to be compatible with observations a sensitivity analysis concerning some parameters of the faults namely length width and slip magnitude has been performed in order to explore their influence on the tsunami features the main result of this paper is that we cannot discriminate between the cv and vv sources both are in agreement with some historical observations whilst they do not match others we believe that a better tuning of the source mechanism over these faults can improve the agreement between model computations and historical observations

webgis for italian tsunami a useful tool for coastal planners abstract ritmare is the italian contribution to a sea research program promoted by the european commission aiming to create an integrated maritime policy in this context a geodatabase about tsunami events recorded along the italian coasts as reported in recent scientific papers has been realized each scientific paper occurring in the geodatabase is linked to its area of interest by means of a geographical information system gis the geodatabase is available on the ritmare website www ritmare it through a map server

paleozoic multiple accretionary and collisional processes of the beishan orogenic collage in the paper by xiao and others american journal of science v 310 p 1553 1594 1 please substitute figure 16 reproduced here for figure 16 that appears between pages 1573 and 1574 the original figure 16 2 was printed at an improper size figure 3 1 lookup volpage 310

constraints on the timing of uplift of the yanshan fold and thrust belt north china this paper reports in situ u pb ages and hf isotopic data on detrital zircons from paleozoic to late mesozoic strata in the xishan area near beijing that provide important constraints on the evolution and paleogeography of the northern part of the north china craton ncc zircons from carboniferous to late mesozoic sandstones are characterized by three major groups of u pb ages 2 5 2 3 ga 1 9 1 7 ga and late phanerozoic ages the neoarchean and paleoproterozoic zircons and some phanerozoic zircons have negative ehf t values similar to igneous zircons from intrusive rocks known from the ncc indicating that the source of the sandstones was locally derived however late triassic to late jurassic 205 158 ma sandstones contain a group of phanerozoic zircons with positive ehf t values distinct from known igneous zircons in the ncc suggesting an exotic source the nearest potential source is the xing meng orogenic belt xmob to the north of the ncc where considerable amounts of juvenile crustal materials exist it is concluded that there are two sudden shifts in source provenances of the xishan sediments from the ncc before the late triassic to a mixed source from the ncc and xmob during the late triassic to late jurassic and then from the ncc again during the late jurassic 158 ma the first shift in source resulted from the exhumation and denudation of rocks due to uplift of the xmob which coincided with post collisional extension in the late triassic and intraplate extension of the ncc in the middle to late jurassic the second source shift resulted from the uplift of the yanshan fold and thrust belt thus constraining the timing of this to the late jurassic

approaching the seismogenic source of the calabria 8 september 1905 earthquake new geophysical geological and biochemical data from the s eufemia gulf s italy abstract recognizing the seismogenic source of major historical earthquakes particularly when these have occurred offshore is a long standing issue across the mediterranean sea and elsewhere the destructive earthquake m 7 that struck western calabria southern italy on the night of 8 september 1905 is one such case having various authors proposed a seismogenic source with apparently diverse hypotheses and without achieving a unique solution to gain novel insight into the crustal volume where the 1905 earthquake took place and to seek a more robust solution for the seismogenic source associated with this destructive event we carried out a well targeted multidisciplinary survey within the gulf of s eufemia se tyrrhenian sea collecting geophysical data oceanographic measurements and biological chemical and sedimentary samples we identified three main tectonic features affecting the sedimentary basin in the gulf of s eufemia 1 a ne sw striking ca 13 km long normal fault here named s eufemia fault 2 a wnw striking polyphased fault system and 3 a likely e w trending lineament among these the normal fault shows evidence of activity witnessed by the deformed recent sediments and by its seabed rupture along which locally fluid leakage occurs features in agreement with the anomalous distribution of prokaryotic abundance and biopolymeric c content resulted from the shallow sediment analyses the numerous seismogenic sources proposed in the literature during the past 15 yr make up a composite framework of this sector of western calabria that we tested against a the geological evidence from the newly acquired dataset and b the regional seismotectonic models such assessment allows us to propose the ne sw striking normal fault as the most probable candidate for the seismogenic source of the 1905 earthquake reappraising a major historical earthquake as the 1905 one enhances the seismotectonic picture of western calabria further understanding of the region and better constraining the location of the seismogenic source may be attained through integrated interpretation of our data together with a on land field evidence and b seismological modeling

paleoproterozoic multiphase magmatism and metamorphism recorded in metamorphic basement rocks of the northern altyn tagh southeastern tarim craton abstract the paleoproterozoic is a pivotal time for understanding the geochronological framework of the tarim craton located at the southeastern margin of the tarim craton the northern altyn tagh is the main region of exposed paleoproterozoic magmatic and metamorphic rocks these rocks are diverse diachronous and modified by multiphase tectonothermal events in this study we performed systematic analyses on the amphibolite felsic gneisses and metasedimentary rocks in the aketashitage area southeastern tarim craton including petrography mineral chemistry and whole rock geochemistry as well as in situ zircon u pb ages and hf isotopes to examine the paleoproterozoic magmatic metamorphic events in the northern altyn tagh results from our study indicate that geochemically the amphibolite and felsic gneisses in the aketashitage area resemble the typical bimodal associations of mafic and acidic volcanic rocks in addition felsic gneisses are characterized by high sr and low y contents high sr y and la yb n ratios and indistinctive eu anomalies closely resembling high sio2 adakites derived from subducted basaltic slab melt the palimpsest textures and geochemical features of the aketashitage metasedimentary rocks suggest that their protoliths are argillaceous rocks the amphibolite from the study area has a metamorphic age of 1 96 ga and the felsic gneisses yield crystallization ages of 2 54 2 52 ga the major age peaks of metasedimentary rocks in the aketashitage area namely 2 72 ga 2 05 ga and 1 97 ga are remarkably consistent with the magmatic and or metamorphic events in the same area furthermore the minimum age peak of the studied metasedimentary rocks suggests a depositional age no earlier than 1 97 ga geochemical and geochronological evidence from the exposed rock associations in the aketashitage area suggest a subduction related tectonic setting during the paleoproterozoic our new data combined with the findings of previous studies indicate that paleoproterozoic magmatism and metamorphism in the northern altyn tagh area are nearly synchronous and that both are likely related to oceanic subduction

evaluation of tsunami flooding using geomorphologic evidence abstract whatever the generating mechanism of a tsunami may be this event can discharge destructive energy along coastal areas and produce widespread inundation the presence of large boulders along rocky coasts could be a useful indicator to understand the extent of the impact of past tsunami floods a detailed study of the deposited boulder features size shape and rock density and their initial position prior to the transport is extremely important when reconstructing the possible morphodynamic scenario s applying the appropriate equations is important when aiming to assess the maximum extent of flooding the integration of morphological and hydrodynamic data allows for an estimation of the water level during the tsunami event responsible for boulder transport moreover it is possible to calculate how far the impacting wave flooded inland this is a function of the wave parameters and of the degree of roughness of the flooded terrain that is expressed by the manning number to evaluate its probable average value experimental data computer simulations and post tsunami surveys have been performed in two sectors of the southern apulia coastline characterised by the presence of tsunami boulder fields and or ridges the surveys in each site have allowed for the calculation of the boulder sizes the estimation of their pre transport location and the extent of inland flooding data have been processed using a geographic information system gis as a result a flooding map useful in planning future possible actions for coastal area use has been produced

shaking scenarios from multiple source models shed light on the 8 september 1905 mw 7 calabria earthquake southern italy project istege indagine sismotettonica del terremoto dell 8 settembre 1905 mw 7 4 nel golfo di sant eufemia offshore tirrenico calabrese supported by ogs istituto nazionale di oceanografia e di geofisica sperimentale project ritmare funded by dipartimento della protezione civile italy s national civil protection

the capo vaticano calabria coastal terraces and the 1905 m7 earthquake the geomorphological signature of regional uplift and coseismic slip in southern italy terra nova 22 378 389 2010 abstract the elevation of the capo vaticano coastal terraces tyrrhenian coast central calabria is the result of a combination of regional uplift and repeated coseismic displacement we subtract the regional uplift from the total uplift maximum average uplift rates 0 81 0 97 mm a 1 since c 0 7 ma and obtain the residual fault related displacement then we model the residual displacement to provide constraints on the location and geometry of the seismogenic source of the 1905 m7 earthquake the strongest and still poorly understood earthquake of the instrumental era in this area we try four different potential sources for the dislocation modelling and find that 1 three sources are not compatible with the displacement observed along the terraces and 2 the only source consistent with the local deformation is the 100 striking coccorino fault we calculate average long term vertical slip rates of 0 2 0 3 mm a 1 on the coccorino fault and estimate an average recurrence time of one millennium for a 1905 type earthquake

seismicity and p wave velocity image of the southern tyrrhenian subduction zone summary this paper focuses on the deep earth structure and earthquake distribution within the southern tyrrhenian subduction zone we discuss seismological observations which provide insight into the mechanics of subduction processes for an unusual compressional margin the motivation for this work derives from the recognition that little is known about one of the most intriguing geodynamic features of the italian peninsula and the fact that a large amount of information can be extracted from data collected by the istituto nazionale di geofisica national seismic network we show that the hypocentres of intermediate and deep earthquakes that have occurred since 1988 image a nw dipping plane continuous from the ionian sea to the tyrrhenian down to 450 km depth we also present a 3 d model of the deep structure beneath southern italy derived using deep earthquake seismic tomography tomographic images reveal a high velocity body dipping from the apulian and iblean forelands towards the tyrrhenian basin in the crust and upper mantle at least down to 320 km depth this high velocity body may be related to the cold subducted ionian lithosphere earthquake hypocentres are confined within the high velocity body delineating the subduction beneath the calabrian arc

high resolution morpho bathymetric imaging of the messina strait southern italy new insights on the 1908 earthquake and tsunami the 28 december 1908 reggio calabria and messina earthquake named after the two most damaged cities on the coasts of messina strait was one of the strongest mw 7 1 ever to occur in italy and was also followed by a tsunami that severely impacted the coasts of the strait although there is general agreement that its epicentre is located offshore in the messina strait the source fault has never been detected a century long question is therefore pending on the source of both the 1908 earthquake and tsunami within the ongoing debate on this subject little attention has been given so far to morphological insights from high resolution bathymetric multibeam data particularly as regarding the evidence of faults affecting the seafloor and the question of whether a submarine landslide may had been the cause of the tsunami we aim to address this issue by presenting the results of a morpho bathymetric study in the messina strait and surroundings investigated by means of high resolution swath bathymetry the primary morpho structural feature in this area is the axial channel of the messina canyon towards which flow several tributary canyons that incise the steep continental slope on the calabrian and sicilian margins these canyons carve deeply into a very narrow almost lacking continental shelf and merge laterally forming a continuous erosional margin rimming the messina strait this giant composite canyon environment is the locus of intense erosional and depositional processes that superimpose on active tectonic deformation resulting in a complex geomorphology that hinders the distinction between tectonic and sedimentary features seafloor ruptures that may be linked to fault systems compatible with the source of the 1908 earthquake and tsunami could not be identified based from our morpho bathymetric analysis however we provide evidence of several geomorphic features indicative of tectonic deformation in the messina strait define the presence and distribution of submarine landslides and evaluate their possible role as tsunami sources

evidence of vertical tectonic uplift at briatico calabria italy inferred from roman age maritime archaeological indicators abstract calabria is one of the most complex geological regions of the mediterranean basin which experienced large earthquakes and uplift and is still undergoing active tectonics along its coasts are located archaeological sites that can be used as powerful indicators of the relative vertical movements between land and sea since their construction this paper presents and discusses data on the relative sea level change as estimated from maritime archaeological indicators of the last 2 0 ka bp existing along the tyrrhenian coast of briatico these sites still show the remnants of a roman age fish tank and a submerged breakwater about 320 m long the palaeo sea level has been obtained measuring the functional elevation of the significant archaeological markers their elevation was compared against the latest predicted sea level curve for the holocene along the tyrrhenian coast of calabria as this coastal area is affected by significant and continuous vertical tectonic uplift during pleistocene the data show the counterbalance between coastal uplift and relative sea level change caused by the glacio hydro isostasy acting since the construction of these archaeological sites the sum of these movements determined an about null relative sea level change for this location these data are in contrast with other part of the tectonically stable areas of the mediterranean and provide evidence that crustal uplift continued in the last 1806 50 y at a rate of 0 65 mm y

rare earth element patterns in archean high grade metasediments and their tectonic significance abstract metasediments from two contrasting types of archean high grade terrains are interpreted as being derived from distinct tectonic settings the kapuskasing structural zone canada represents the deep roots of a typical greenstone belt whereas the limpopo province southern africa and western gneiss terrain australia mainly consist of shelf sediments deposited on a granitic basement and then buried to the depths required for granulite fades metamorphism upper amphibolite to granulite fades paragneisses from the kapuskasing structural zone have ree patterns similar to those of greenstone belt sediments except where partial melting has occurred forming restites with eu enrichment and melts with eu depletion except in this latter instance metamorphism has not affected the primary ree patterns ree patterns in archean upper amphibolite to granulite facies metasediments from the central limpopo province and western gneiss terrain show wide differences ranging from patterns which resemble those in post archean terrigenous sediments to typical archean sedimentary rock patterns the diversity in ree patterns for these shallow shelf metasediments is interpreted as resulting from derivation from local provenances samples with post archean patterns displaying eu depletion are interpreted as being derived from k rich granitic plutons which were portions of small stable early archean terrains precursors of the widespread late archean proterozoic episode of major cratonic development

recent and active tectonics in the calabrian arc southern italy normal faulting which has developed since the middle pleistocene with an overall ese wnw extension is the dominant mode of deformation which has characterized the calabrian arc up to the present quaternary normal faults extend for a total length of about 180 km along the inner side of the arc the different normal fault segments which during the pleistocene controlled the evolution of the main marine sedimentary basins are varying in length from 10 to 20 km and have fault escarpments showing a very young morphology which define the fronts of the major mountain ranges of the arc the morphological features of the fault escarpments suggest slip rates of 0 8 1 1 mm yr for the last 700 k y and values of 0 6 0 9 mm yr for the last 120 k y indicating a uniform rate of faulting since the middle pleistocene crustal seismicity and the mesoseismic areas of historical large events 6 5 m 7 1 which occurred in the calabrian arc are located within a narrow belt along the hanging walls of the quaternary normal fault segments this suggests that the normal faults which dissect the inner side of the calabrian arc may be seismically active

tsunami taxonomy and detection from recent mediterranean tide gauge data abstract sea level records collected in digital form with high sampling rate by recently upgraded tide gauges located along the mediterranean coasts are subjected to a posteriori investigation to examine and characterize occurrence of sea level oscillations in the tsunami period range induced by both underwater or coastal earthquakes and by meteorological events after performing a rigorous quality control procedure on the raw sea level time series a wavelet based analysis is applied to 2 h high pass filtered data to identify oscillations generated by earthquakes and a few events are modeled aiming to verify travel time and expected spectral shape seismic tsunami oscillations that are not reported in published catalogues are identified in the sea level records of the period 2010 2014 just after three different earthquake events a method is proposed to detect occurrence of tsunami like oscillations of meteorological origin from the available tidal records based on the distribution of the detided level process over spectral bandwidth parameter and mean period the developed methodology is also the first presented which allows to distinguish sea wave induced harbor seiches from fluctuations of meteorological origin associated with passage of atmospheric disturbances meteotsunamis in sea level time series the results of the analyses show that during the considered period in the mediterranean sea tsunamis of seismic origin are rare and weak meteotsunamis on the contrary are relatively frequent and in critical areas may reach intensities exceeding astronomical tide the availability of the recently acquired high frequency records and the presented approach allow to extend the list of recorded tsunami events of both seismic and meteorological origin the identified event sets may be used for improved hazard analyses and risk assessments along the mediterranean coasts

the generating mechanisms of the august 17 1999 izmit bay turkey tsunami regional tectonic and local mass instabilities causes abstract the m w 7 4 earthquake that affected the northwestern part of turkey on august 17 1999 and in particular the gulf of izmit had dramatic consequences also as regards tsunami generation the main cause of the earthquake was a dextral strike slip rupture that took place along different segments of the western part of the north anatolian fault wnaf the rupture process involved not only a number of distinct strike slip fault segments but also dip slip ancillary faults connecting the main transcurrent segments the general picture was further complicated by the occurrence of subsidence and liquefaction phenomena especially along the coasts of the izmit bay and in the sapanca lake tsunami effects were observed and measured during post event surveys in several places along both the northern and the southern coasts of the bay the run up heights in most places were reported to lie in the interval 1 3 m but in the small town of degirmendere where a local slump occurred carrying underwater buildings and gardens of the waterfront sector eyewitnesses reported water waves higher than 15 m the purpose of this work is to investigate on the causes of the tsunami by means of numerical simulations of the water waves we show that the tsunami was a complex event consisting at least of the combination of a regional event due to tectonic causes and of a local event associated with the mass failure as to the first we are able to demonstrate that the observed tsunami cannot be explained only in terms of the sea bottom dislocation produced by the main right lateral dislocation but that the prominent contribution comes from the displacement associated with the secondary shallow normal faults furthermore the large waves and effects seen in degirmendere can be explained as the consequence of the slump by means of a stability analysis based on an original method making use of the limit equilibrium concept we show that the slump was highly stable before the earthquake and that it was triggered by seismic waves simulation of the tsunami induced by the slump was carried out by a two step numerical code that computes the landslide motion first and then the generated water wave propagation it is shown that the computed local tsunami matches the experimental data