rock surface modeling as a tool to assess the morphology of inland notches mount carmel israel abstract inland notches are elongated c shape indentations carved into hard dense carbonate rocks of the mediterranean climate zone in recent years these unique features became of particular interest as geoindicators of denudation and slope erosion processes the study goals are to learn the processes acting upon the notches cavity by 1 examining the micromorphology of the backwall 2 identifying and classifying zones of erosion 3 learning the surface flow pattern and 4 proposing an erosion mechanism induced by exfoliation to this end a machine learning algorithm was designed using the microstructure texture streamlines formation and potential focal flow the workflow uses data from terrestrial laser scanning applies high resolution textural and curvature analyses and trains an artificial neural network to the different segments of the notch the reconstructed surface model shows division into three distinct belts within the cavity surface 1 the spalled belt sb 2 the transition zone belt tz and 3 the deposition belt db each belt owes its distinct microtopography implying on different geomorphic processes the newly developed methodology improves the recognition of streamline networks along the cavity backwall which mimic alluvial networks the organization of the reconstructed micro channels is similar to drainage basin systems where first order channels developed upstream converge into larger ones and diverge as distributaries as the gradient decreases depositing tufa along the notches base

seismicity normal faulting and the geomorphological development of the gulf of corinth greece the corinth earthquakes of february and march 1981 three major destructive earthquakes of m s 6 7 6 4 6 4 occurred in the eastern part of the gulf of corinth in february and march 1981 associated normal faulting was observed on both the north and the south sides of the gulf examination of teleseismic local seismic surface faulting and geomorpbological data suggests that the first and second of these shocks activated major north dipping normal faults these faults control the topography and bathymetry and are related to the recent uplift and subsidence of the coastline it is probable that the first earthquake occurred on a faultwhich outcrops underwater and the second on a fault which is visible on land it appears that the third shock activated an antithetic normal fault dipping southwards on the north side of the gulf and that the overall structure of the gulf of corinth graben is asymmetric the northern antithetic fault clearly demonstrates the geomorphological changes associated with developing young normal faulting in addition we suggest that observations of recent coastline movement provide a powerful tool for identifying major active fault systems and predicting their historical role in the paleogeography of an area

uplift deformation and fluid involvement within an active normal fault zone in the gulf of corinth greece the active pisia fault zone is exposed close to the crest of a rotated carbonate fault block that forms part of the southern margin to the gulf of corinth half graben in central greece the crest of the fault block lies above sea level whilst in the hanging wall a marine basin exists as a result the diagenetic and structural characteristics of the fault zone record complex fluid involvement both early phreatic carbonate syn kinematic cements characterized by drusy fabrics baroque dolomites and crack seal textures and late vadose carbonate syn kinematic cements characterized by flowstones containing cave collapse debris exist in the uplifted footwall to the fault downward percolation of vadose meteoric waters and the upwelling of pore waters with elevated temperatures produced the diagenetic features observed within the fault zone the co existence of early phreatic and late vadose cements within the fault zone is related to footwall uplift across the water table and subsequent erosional unroofing the present day elevation of phreatic cements to c 650m above current sea level provides a minimum estimate of footwall uplift along the fault the wider implication is that temporal changes in deformation and fluid flow may typify fault block evolution

the sparta fault southern greece from segmentation and tectonic geomorphology to seismic hazard mapping and time dependent probabilities the sparta fault system is a major structure approximately 64 km long that bounds the eastern flank of the taygetos mountain front 2407 m and shapes the present day sparta basin it was activated in 464 b c devastating the city of sparta this fault is examined and described in terms of its geometry segmentation drainage pattern and post glacial throw emphasising how these parameters vary along strike qualitative analysis of long profile catchments shows a significant difference in longitudinal convexity between the central and both the south and north parts of the fault system leading to the conclusion of varying uplift rate along strike catchments are sensitive in differential uplift as it is observed by the calculated differences of the steepness index ksn between the outer ksn 83 and central parts 121 ksn 138 of the sparta fault along strike the fault system based on fault throw rates and the bedrock geology a seismic hazard map has been constructed that extracts a locality specific long term earthquake recurrence record based on this map the town of sparta would experience a destructive event similar to that in 464 b c approximately every 1792 458 years since no other major earthquake m 7 0 has been generated by this system since 464 b c a future event could be imminent as a result not only time independent but also time dependent probabilities which incorporate the concept of the seismic cycle have been calculated for the town of sparta showing a considerably higher time dependent probability of 3 0 1 5 over the next 30 years compared to the time independent probability of 1 66 half of the hanging wall area of the sparta fault can experience intensities ix but belongs to the lowest category of seismic risk of the national seismic building code on view of these relatively high calculated probabilities a reassessment of the building code might be necessary

on two interacting creeping vertical surface breaking strike slip faults in a two layer model of the lithosphere abstract two aseismically creeping long vertical surface breaking parallel strike slip faults are taken to be situated in an elastic layer resting on and in welded contact with a visco elastic halfspace representing the lithosphere asthenosphere system solutions are obtained for the displacements stresses and strains using a technique involving the use of green s functions and integral transforms for three possible cases the case of the absence of any fault creep the case in which one fault is creeping and the other is locked and the case in which both faults are creeping taking into account the displacements and stresses present initially and assuming that the tectonic forces maintain a shear strain far away from the faults the types of fault creep for which the displacements stresses and strains are finite everywhere in the model near the faults are identified and the conditions satisfied by these types of fault creep are determined in a simple form fault creep across a fault is generally found to reduce the rate of accumulation of shear stress near the fault the effect of aseismic creep across one fault on the shear stress near the other fault is found to depend on the distance dimensions relative position and other characteristics of the two faults fault creep across one fault is generally found to reduce the rate of shear stress accumulation near the neighbouring fault in the theoretical model considered under suitable circumstances aseismic creep across one of the faults is found to result in aseismic release of shear stress near both faults thus reducing progressively the possibility of a sudden fault movement generating an earthquake the influence of one creeping fault on another is found to decrease rapidly with increase in the distance between the faults the possible uses of the model in the study of the interaction between neighbouring strike slip faults in a layered model representing the lithosphere asthenosphere system and in the estimation of return times of earthquakes is examined

monitoring aseismic surface creep along the north anatolian fault turkey using ground based lidar abstract we studied the surface creep along the north anatolian fault naf one of the most seismically active structures of the eastern mediterranean by using a ground based light detection and ranging lidar system at the ismetpasa and destek sections aseismic surface creep has been known to exist at ismetpasa since the 1970s but it has not been previously reported for the destek site three manmade walls across the fault were monitored for 3 yrs between june 2007 and november 2009 using lidar the surveys revealed that a significant amount of aseismic strain is being continuously released along these sections of the naf 6 8 10 0 4 0 mm yr and 9 1 10 1 4 0 mm yr at two sites near ismetpasa and 6 0 7 2 4 0 mm yr at destek despite this these fault segments are still capable of generating large earthquakes since 50 70 of the yearly slip i e 20 25 mm yr still accumulates on the fault as was demonstrated by the well known 20th century earthquake sequence of 1939 1999

structural anisotropy of normal fault surfaces abstract precise description of natural fault surfaces is indispensable to understanding the geometry mechanics and fluid transport properties of faults profiles of fault surfaces in the wasatch fault zone and oquirrh mountains utah are measured at 30 increments within the fault plane to determine the directional anisotropy of surface roughness at wavelengths between 10 3 m and 30 m and then compared with profiles of larger scale fault surfaces surface anisotropy and an increasing ratio of surface amplitude to wavelength are consistent with self affine fault topography at wavelengths between 1 mm and approximately 5 km fractal dimension of surface profiles generally decreases systematically as the angle to the slip direction increases directional anisotropy is described by an azimuthal scaling function k sin 0 or af af max 1 sin 1 where and af are the amplitude to wavelength ratio and anisotropy factor respectively at azimuth measured clockwise relative to slip direction within the fault surface and 0 is the amplitude to wavelength ratio parallel to slip direction k 90 0 is an anisotropy coefficient and increases systematically with spatial wavelength on the fault surface characterization of natural fault surfaces provides parameters such as fractal dimension d intercept log c of power spectra profile variance and variation in anisotropy factor af which are needed to generate fractal models of natural fault surfaces using spectral synthesis we generate sample models which illustrate the differences between fault surfaces characterized by constant versus azimuthally varying fractal dimension the latter model surfaces contain low amplitude corrugations superimposed on elongate ridges which parallel slip direction this surface texture resembles that of natural fault surfaces that refract across lithologic layering or are cut by secondary faults such as r and r shears

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

seismic history of a bedrock fault scarp using quantitative morphology together with multiple dating methods a case study of the luoyunshan piedmont fault southwestern shanxi rift china abstract the study of bedrock fault scarps is a useful approach to identify paleo earthquakes and acquire the faulting history in bedrock areas where traditional trench techniques are not applicable here we report a study on the luoyunshan piedmont fault lyspf southwestern shanxi rift china although several studies have analyzed the lyspf its faulting behavior is still under debate for example the tectonic geomorphology fails to determine the frequency of past slips and the elapsed time to address these problems we investigated two bedrock fault surfaces luoyuncun northern segment and weicun southern segment using quantitative morphology analyses together with multiple quaternary dating techniques quantitative morphology analysis shows that both bedrock fault surfaces have the characteristics of vertical segmentation this kind of segmentation indicates that the fault surfaces are exhumed intermittently likely owing to periodic faulting earthquakes therefore earthquake events can be identified as morphological segments and the corresponding co seismic displacement can be determined by the height of these segments according to the results from the quantitative morphology and dating techniques four seismic events with a co seismic vertical displacement of 0 9 m 0 82 m 1 64 to 2 38 m and 2 30 to 2 54 m on the northern segment occurred during the late pleistocene whereas two seismic events with a co seismic vertical displacement of 1 33 m and 1 to 1 08 m are identified on the southern segment occurred during the holocene combined with the results of knickpoint series and trench techniques of the lyspf eight paleo earthquake events were identified since 45 ka with an average recurrence interval of 5 8 kyr the more complete paleo earthquake sequence also showed the possibility that the variation of the slip rate along the lyspf depends on the segment and that the displacement produced by the linfen m 7 earthquake of 649 ce has been recorded at the wc fault surface

roughness of natural fault surfaces the roughness of fault surfaces is important in the mechanics of fault slip and could play a role in determining whether sliding occurs via earthquakes or fault creep we have made preliminary measurements of the power spectral density of several fault surfaces over the wavelength range from 10 5 to 1 m using field and laboratory scale profilimeters the fault surfaces are strongly anisotropic profiles parallel to the slip direction have amplitudes about one order of magnitude lower than those perpendicular to the slip direction over most of the wavelength interval measured fault roughness perpendicular to the slip direction is similar to the roughness of natural joints the greater smoothness in the slip direction presumably represents wear resulting from slip combining our data with previous measurements of the roughness spectrum of the san andreas fault shows that fault surfaces are fractal over nearly eleven orders of magnitude in wavelength

use of small unmanned aerial vehicle suav acquired topography for identifying and characterizing active normal faults along the seerteng shan north china abstract high resolution topographic datasets are being increasingly applied in studies of active tectonics for precise quantification of lateral and vertical offsets of landforms digital elevation models dem acquired by airborne light detection and ranging lidar have also been used for morphological analysis of tectonic scarps to infer the seismic slip history of active faults however the high cost of conducting lidar studies limits its widespread application in contrast the potential applicability of the low cost and portable small unmanned aerial vehicles suav combined with structure from motion sfm techniques to investigate morphological features of fault generated scarps and their paleoseismic implications has not been fully explored here based on suav acquired dems and field observations we present a case study of the morphological features of fault scarps along the seertengshan piedmont fault spf a major boundary fault of the hetao graben north china and discuss their paleoseismic implications the results demonstrate that low angle 2000 years ago the observed 1 8 2 5 m high fault scarps with single slope sections probably represent the most recent incremental displacements associated with surface rupturing earthquake s topographic data acquired by suav are suitable for quantitative morphological analyses of fault generated scarps in actively deforming regions and can contribute to assessments of seismic hazard

relationships between fault geometry slip rate variability and earthquake recurrence in extensional settings field observations and modelling indicate that elastic interaction between active faults can lead to variations in earthquake recurrence intervals measured on timescales of 102 104 yr fault geometry strongly influences the nature of the interaction between adjacent structures as it controls the spatial redistribution of stress when rupture occurs in this paper we use a previously published numerical model for elastic interaction between spontaneously growing faults to investigate the relationships between fault geometry fault slip rate variations and the statistics of earthquake recurrence these relationships develop and become systematic as a long term consequence of stress redistribution in individual rupture events even though on short timescales earthquake activity appears to be stochastic we characterize fault behaviour using the coefficient of variation cv of earthquake recurrence intervals and introduce a new measure slip rate variability srv that takes into account the size and time ordering of slip events cv generally increases when the strain is partitioned on more than one fault but the relationship between long term fault slip rate srmean and cv is poorly defined in contrast srv increases systematically where faulting is more distributed and srmean is lower to first order srv is inversely proportional to srmean we also extract earthquake recurrence statistics and compare these to previously published probability density functions used in earthquake forecasting the histograms of earthquake recurrence vary systematically as a function of fault geometry and are best characterized by a weibull distribution with fitting parameters that vary from site to site along the fault array we explain these phenomena in terms of a time varying geometrical control on stress loading of individual faults arising from the history of elastic interactions and compare our results with published data on srv and earthquake recurrence along normal faults in new zealand and in the italian apennines our results suggest that palaeoseismic data should be collected and analysed with structural geometry in mind and that information on srv cv and srmean should be integrated with data from earthquake catalogues when evaluating seismic hazard

an analytical model for the underwater sound pressure waveforms radiated when an offshore pile is drivena an analytical model has been developed for the pile vibration and consequent sound pressure and particle velocity radiated underwater when an offshore cylindrical pile is struck by a drop hammer the model which is based on the coupled equations of motion for axial and radial vibration of a thin cylindrical shell yields frequency dependent phase velocity and attenuation of these vibrations the amplitude of the pulse of axial and radial displacement that travels down a pile following an axial impact is described in terms of the hammer properties solutions are obtained for the radiated sound pressure and particle velocity using junger and feit s transform formulation of the pressure field of cylindrical radiators acoustical society of america new york 1993 p 216 the model is applied to published data on radiated noise from offshore driving of a steel pile the modeled pressure waveforms at 12 m horizontal range and at 9 hydrophone depths correlate significantly with the measured waveforms the modeled pressures of the initial positive peaks appropriately low pass filtered agree with data to within 1 db the initial negative peaks however exceed the data by up to 7 db and as hydrophone depth increases the model negative peaks have a maximum at 7 m whereas the data have a maximum at 9 m

fault slip distribution and fault roughness summary we present analysis of the spatial correlations of seismological slip maps and fault topography roughness illuminating their identical self affine exponent though the complexity of the coseismic spatial slip distribution can be intuitively associated with geometrical or stress heterogeneities along the fault surface this has never been demonstrated based on new measurements of fault surface topography and on statistical analyses of kinematic inversions of slip maps we propose a model which quantitatively characterizes the link between slip distribution and fault surface roughness our approach can be divided into two complementary steps i using a numerical computation we estimate the influence of fault roughness on the frictional strength pre stress we model a fault as a rough interface where elastic asperities are squeezed the hurst exponent h characterizing the self affinity of the frictional strength field approaches h h 1 where h is the roughness exponent of the fault surface in the direction of slip ii using a quasi static model of fault propagation which includes the effect of long range elastic interactions and spatial correlations in the frictional strength the spatial slip correlation is observed to scale as hs h 1 where hs represents the hurst exponent of the slip distribution under the assumption that the origin of the spatial fluctuations in frictional strength along faults is the elastic squeeze of fault asperities we show that self affine geometrical properties of fault surface roughness control slip correlations and that hs h given that h 0 6 for a wide range of faults various accumulated displacement host rock and slip movement we predict that hs 0 6 even if our quasi static fault model is more relevant for creeping faults the spatial slip correlations observed are consistent with those of seismological slip maps a consequence is that the self affinity property of slip roughness may be explained by fault geometry without considering dynamical effects produced during an earthquake

innovative tidal notch detection using tls and fuzzy logic implications for palaeo shorelines from compressional crete and extensional gulf of corinth tectonic settings abstract tidal notches are a generally accepted sea level marker and maintain particular interest for palaeoseismic studies since coastal seismic activity potentially displaces them from their genetic position the result of subsequent seismic events is a notch sequence reflecting the cumulative coastal uplift in order to evaluate preserved notch sequences an innovative and interdisciplinary workflow is presented that accurately highlights evidence for palaeo sea level markers the workflow uses data from terrestrial laser scanning and iteratively combines high resolution curvature analysis high performance edge detection and feature extraction based on the assumptions that remnants such as the roof of tidal notches form convex patterns edge detection is performed on principal curvature images in addition a standard algorithm is compared to edge detection results from a custom fuzzy logic approach the results pass through a hough transform in order to extract continuous line features of an almost horizontal orientation the workflow was initially developed on a single distinct and sheltered exposure in southern crete and afterwards successfully tested on laser scans of different coastal cliffs from the perachora peninsula this approach allows a detailed examination of otherwise inaccessible locations and the evaluation of lateral and 3d geometries thus evidence for previously unrecognised sea level markers can be identified even when poorly developed high resolution laser scans of entire cliff exposures allow local variations to be quantified edge detection aims to reduce information on the surface curvature and hough transform limits the results towards orientation and continuity thus the presented objective methodology enhances the recognition of tidal notches and supports palaeoseismic studies by contributing spatial information and accurate measurements of horizontal movements beyond that recognised during traditional surveys this is especially useful for the identification of palaeo shorelines in extensional tectonic environments where coseismic footwall uplift only 1 2 to 1 4 of net slip per event is unlikely to raise an entire notch above the tidal range

introduction to special section paleoseismology a proverb of confucius states study the past if you would divine the future if we could learn about the past history of earthquakes on a specific fault then we could serve society well by better forecasting the future earthquake behavior of that fault for most of the world the period of historical records is short about 200 years in california and less than that in new zealand oregon and other parts of the world and even where the historical record is thousands of years long such as in north central china or the eastern mediterranean region it is commonly difficult to correlate a major historical earthquake with a specific active fault even if this correlation could be made without ambiguity the recurrence intervals for many faults are longer than even a historical record of several thousand years for these reasons the history of large earthquakes on faults must for the most part be learned from the geological record

weathering history of an exposed bedrock fault surface interpreted from its topography abstract morphologic features of bedrock fault scarps are underutilized in studying faulting and weathering history partly because of a lack of accurate quantitative parameters for topography the study employs ground based lidar to measure five patches at different levels on the same fault surface and then calculates roughness in the form of power spectral density in directions parallel and perpendicular to the slip the power spectral density and spatial frequency typically follow a power law for each fault patch showing approximately linear relationships in a log log plot however due to additional power introduced by weathering all spectral curves especially those parallel to the slip can be divided into two segments lower frequency wavelengths of several centimeters several meters and higher frequency wavelengths of several centimeters and below domains this shows that the topographic features at different spatial scales are dominated by different mechanical processes faulting abrasion in the lower frequency domain and the weathering process in the higher frequency domain moreover we develop two parameters to quantify the degree of weathering of a fault outcrop which is significant to describe the evolution of the fault scarp and infer the date of faulting under calibration

quantitative morphology of bedrock fault surfaces and identification of paleo earthquakes the quantitative analysis of morphologic characteristics of bedrock fault surfaces may be a useful approach to study faulting history and identify paleo earthquakes it is an effective complement to trenching techniques especially to identify paleo earthquakes in a bedrock area where trenching technique cannot be applied in this paper we calculate the 2d fractal dimension of three bedrock fault surfaces on the huoshan piedmont fault in the shanxi graben china using the isotropic empirical variogram we show that the fractal dimension varies systematically with height above the base of the fault surface exposures indicating a segmentation of the fault surface morphology we interpret this segmentation as being due to different exposure duration of parallel fault surface bands caused by periodical earthquakes and discontinuous weathering we take the average of fractal dimensions of each band as a characteristic value to describe its surface morphology which can be used to estimate the exposure duration of the fault surface band and then the occurrence time of the earthquake that exposed the band combined with previous trenching results we fit an empirical relationship between the exposure duration and the morphological characteristic value on the fault d 0 049 t 2 246 the average width of those fault surface bands can also be regarded as an approximate vertical coseismic displacement of characteristic earthquake similar to the hongdong m8 earthquake of 1303 based on the segmentation of quantitative morphology of the three fault surfaces on the huoshan piedmont fault we identify three earthquake events the coseismic vertical displacement of the characteristic earthquake on the huoshan piedmont fault is estimated to be 3 4 m the average width of these fault surface bands gaps with a width of 0 1 0 3 m between two adjacent bands in which the fractal value increases gradually with fault surface height are inferred to be caused by weathering between two earthquakes or interseismic slip on the fault

image processing and roughness analysis of exposed bedrock fault planes as a tool for paleoseismological analysis results from the campo felice fault central apennines italy abstract morphologic investigations along the campo felice cf fault central apennines italy have been made in order to develop a procedure for the paleoseismological analysis of bedrock fault scarps the cf fault has been responsible for the formation of an impressive limestone fault scarp geomorphologic work on the cf basin and related fault indicated that the scarp originated from tectonic fault displacements three morphologic units have been distinguished along the fault scarp and defined as morphosome m1 lowest part of the scarp m2 and m3 the uppermost part these units display different karstic features which are the result of their different duration of exposure to weathering micromorphologic analyses focused on the morphosome m1 along which the cf fault plane is exposed for a height ranging between 4 and 7 m these analyses were aimed at defining differently weathered bands located at various heights and parallel to the fault scarp top and base the presence of these bands suggests repeated fault movements the exposed fault surface displays a low grade biokarstic weathering due to the action of epilithic and endolithic organisms the biokarst distribution is however inhomogeneous and conditioned by the presence of nourishing elements moisture and by light intensity an area preferentially affected by the biokarstic processes develops as a band at the bedrock soil contact at the base of the scarp roughness and colour analyses were made to identify uplifted bands which previously formed at the bedrock soil contact the roughness analysis was made using a microroughness meter along 20 cm long horizontal transects repeated each 20 cm of fault height for the entire morphosome m1 at various sites along the scarp the roughness variance data plotted vs the fault height failed to identify differently weathered bands of paleoseismological interest this result is probably due to the complex distribution of biokarst along the investigated fault plane more reliable results have been obtained by areal analysis of the variation of the colour rendering of the rocks exposed along the fault plane at different sites photographic images of large portions of fault surfaces have been processed with standard graphic computer programs the variations of colour indicated the presence of bands at various heights along the fault plane two uplifted bands have been recognised at all the investigated sites suggesting two displacement events e1 and e2 a preliminary chronological framework for these two events the youngest of which affected the cf fault can be derived from the paleoseismological data available for the southernmost branch of the regional fault system that includes the cf fault according to these data e1 may have occurred between 860 and 1300 ad while e2 may have occurred at about 1900 bc work is in progress to define surface exposure ages of different parts of the fault plane by means of in situ produced cosmogenic 36 cl this procedure will give further chronological constraints for the age of e1 and e2 and will also permit to test the validity of the micromorphologic analysis of bedrock fault scarps for paleoseismological aims

slip vector analysis with high resolution t lidar scanning abstract a palaeostress analysis of an active bedrock normal fault scarp based on kinematic indicators is reconstructed using terrestrial laser scanning tls for this purpose three key elements are necessary for a defined region i the orientation of the fault plane ii the orientation of the slickenside lineation or other kinematic indicators and iii the sense of motion of the hanging wall the paper specifies a workflow in order to obtain stress data from point cloud data using terrestrial laser scanning tls in an active tectonic environment the entire analysis was performed on a continuous limestone bedrock normal fault scarp on the island of crete greece at four different locations along the wnw ese striking spili fault at each location we collected data with the terrestrial light detection and ranging system t lidar we then validated the calculated three dimensional stress results at three of the locations by comparison with conventional methods using data obtained manually with a compass clinometer numerous kinematic indicators for normal faulting were discovered on the fault plane surface using t lidar data when comparing all reconstructed stress data obtained from t lidar to that obtained through manual compass measurements the degree of fault plane orientation divergence is 005 03 for dip direction and dip the degree of slickenside lineation divergence is 003 03 for dip direction and dip therefore the percentage threshold error of the individual vector angle at each investigation site is lower than 3 for the dip direction and dip for planes and lower than 6 for the strike the maximum mean variation of the complete calculated stress tensors is 005 03

ages of prehistoric earthquakes revealed by cosmogenic chlorine 36 in a bedrock fault scarp at hebgen lake cosmogenic chlorine 36 reveals dates of the multiple prehistoric earthquakes that have produced a scarp on the hebgen lake fault apparent chlorine 36 ages are stratigraphically correct follow a predicted theoretical pattern and produce geologically reasonable model ages of 24 20 7 0 2 6 1 7 and 0 4 thousand years ago this result demonstrates the feasibility of using cosmogenic chlorine 36 to extract paleoearthquake records from bedrock fault scarps

localization of quaternary slip rates in an active rift in 105 years an example from central greece constrained by 234u 230th coral dates from uplifted paleoshorelines mapping dating and modeling of paleoshorelines uplifted in the footwall of the 1981 gulf of corinth earthquake fault greece ms 6 9 6 7 are used to assess its slip rate history relative to other normal faults in the area and study strain localization the 234u 230th coral ages from cladocora caespitosa date uplifted shoreface sediments and paleoshorelines from glacioeustatic sea level highstands at 76 possibly 100 125 175 200 216 240 and 340 ka uplifted quaternary and holocene paleoshorelines decrease in elevation toward the western tip of the fault exhibiting larger tilt angles with age showing that uplift is due to progressive fault slip since 125 ka uplift rates varied from 0 25 to 0 52 mm yr over a distance of 5 km away from the fault tip tilting was also occurring prior to 125 ka but uplift rates were lower because the 125 ka paleoshoreline is at 77 of the elevation of the 240 ka paleoshoreline despite being nearly half its age comparison of paleoshoreline elevations and sedimentology with the quaternary sea level curve shows that slip rates increased by a factor of 3 2 0 2 at 175 75 ka synchronous with cessation of activity on a neighboring normal fault at 382 112 ka we suggest that the rapid localization of up to 10 15 mm yr of extension into the narrow gulf 30 km wide resulted from synchronous fault activity on neighboring faults followed by localization rather than sequential faulting with consequences for the mechanism controlling localization of extension

first direct observation of coseismic slip and seafloor rupture along a submarine normal fault and implications for fault slip history properly assessing the extent and magnitude of fault ruptures associated with large earthquakes is critical for understanding fault behavior and associated hazard submarine faults can trigger tsunamis whose characteristics are defined by the geometry of seafloor displacement studied primarily through indirect observations e g seismic event parameters seismic profiles shipboard bathymetry coring rather than direct ones using deep sea vehicles we identify for the first time a marker of coseismic slip on a submarine fault plane along the roseau fault lesser antilles and measure its vertical displacement of 0 9 m in situ we also map recent fissuring and faulting of sediments on the hangingwall along 3 km of rupture in close proximity to the fault s base and document the reactivation of erosion and sedimentation within and downslope of the scarp these deformation structures were caused by the 2004 m w 6 3 les saintes earthquake which triggered a subsequent tsunami their characterization informs estimates of earthquake recurrence on this fault and provides new constraints on the geometry of fault rupture which is both shorter and displays locally larger coseismic displacements than available model predictions that lack field constraints this methodology of detailed field observations coupled with near bottom geophysical surveying can be readily applied to numerous submarine fault systems and should prove useful in evaluating seismic and tsunamigenic hazard in all geodynamic contexts

partitioned postseismic deformation associated with the 2009 mw 6 3 l aquila earthquake surface rupture measured using a terrestrial laser scanner using 3d terrestrial laser scan tls technology we have recorded postseismic deformation on and adjacent to the surface rupture formed during the 6th april 2009 l aquila normal faulting earthquake mw 6 3 using surface modeling techniques and repeated surveys 8 124 days after the earthquake we have produced a 4d dataset of postseismic deformation across a 3 65 m area at high horizontal spatial resolution we detected millimetre scale movements partitioned between discrete surface rupture slip and development of a hangingwall syncline over 10 s of meters we interpret the results as the signal of shallow afterslip in the fault zone we find 52 of the total postseismic hangingwall vertical motion occurs as deformation within 30 m of the surface rupture the total postseismic vertical motions are approximately 50 that of the coseismic we highlight the importance of quantifying partitioned postseismic contributions when applying empirical slip magnitude datasets to infer palaeoearthquake magnitudes

future trends in paleoseismology integrated study of the seismic landscape as a vital tool in seismic hazard analyses this paper forms the introduction to this special issue of tectonophysics devoted to selected scientific research presented during events sponsored by the inqua subcommission on paleoseismicity in the past few years in this note we summarize the contents of the contributed papers and use the issues they raise to review the state of the art in paleoseismology from a quaternary geology perspective in our opinion the evolution of paleoseismological studies in the past decade clearly demonstrates that in order to properly understand the seismic potential of a region and to assess the associated hazards broad based multidisciplinary studies are necessary to take full advantage from the geological evidence of past earthquakes a major challenge in future paleoseismic research is to build detailed empirical relations between various categories of coseismic effects in the natural environment and earthquake magnitude intensity these relations should be compiled in a way that is fully representative of the wide variety of natural environments on earth in terms of climatic settings quaternary tectonic evolution rheological parameters of the seismogenic crust and stress environment for instance available data indicate that between earthquake magnitude and surface faulting parameters different scaling laws exist and they are a function of the local geodynamic setting including style of faulting typical focal depths heat flow in this regard we discuss in some detail the concept of seismic landscape which provides the necessary background for developing paleoseismological research strategies the large amount of paleoseismological data collected in recent years shows that each earthquake source creates a signature on the geology and the geomorphology of an area that is unequivocally related with the order of magnitude of its earthquake potential this signature is defined as the seismic landscape of the area e g serva l vittori e ferreli l michetti a m 1997 geology and seismic hazard in grellet b mohammadioun b hays w eds proceedings of the second france united states workshop on earthquake hazard assessment in intraplate regions central and eastern united states and western europe october 16 1995 nice france 20 24 ouest editions nantes france michetti a m hancock p l 1997 paleoseismology understanding past earthquakes using quaternary geology

review of earth science research using terrestrial laser scanning abstract the application of advanced remote sensing technologies including terrestrial laser scanning tls to the earth sciences has increased rapidly in the last two decades improving the spatial and temporal resolution of data terrestrial laser scanning units have evolved into a common tool in studies of spectral and structural geology seismology natural hazards geomorphology and glaciology special consideration of the advantages and limitations of tls in each of these fields is discussed in depth in the context of important work published in each field the workflow used in a tls survey is crucial to the success of the survey and field specific earth science workflows are therefore also discussed products based on tls data such as triangulated irregular networks tin and digital surface models dsm are commonplace tools throughout the earth sciences and the use of these tools to measure slip distributions fault geometries aeolian transport river bed morphologies and flows and other research problems is expanded on where appropriate the review concludes with a discussion of recent trends in tls instrument development and their potential impact on the use of tls in the earth sciences in the future

paleoseismicity of the 1981 corinth earthquake fault seismic contribution to extensional strain in central greece and implications for seismic hazard we present paleoseismological trenching results for the active skinos fault which ruptured the surface on the alkyonides gulf basin margin in the 1981 gulf of corinth earthquake sequence three trenches expose evidence of up to six previous events which are comparable to the 1981 deformation in terms of size and geometry vertical displacement produced by the 1981 earthquake ranged from 0 45 to 1 3 m at the bambakies fan trench sites decreasing towards the eastern fault tip east of the trenches trench 1 reveals two previous events with vertical displacements between 0 5 and 1 2 m since 390 a d trench 2 reveals five or six previous events but these are not dated trench 3 reveals four previous events since 670 a d vertical displacements associated with interpreted paleoearthquakes at the trench sites are 1 2 m the recurrence interval on the skinos fault is estimated to average 330 years however significant variation in recurrence interval is allowed by the available radiometric dates average vertical displacement rates derived from the trenches are in the range 0 7 2 5 mm yr a similar long term average vertical displacement rate of 1 2 2 3 mm yr is estimated for the lifespan of the basin bounding fault this equates to a horizontal seismic strain contribution of 2 5 mm yr from the skinos fault this local seismic strain rate overlaps within error with geodetically determined velocities across the alkyonides gulf assumed to represent uniform deep crustal strain thus seismic deformation on the basin bounding fault system may take up the major part of extension across the basin and aseismic strain is not necessitated by the data if correct this would imply that geodetically determined strain rates may be used as a proxy for potential seismic moment release in seismic hazard analyses for this region

underwater mach wave radiation from impact pile driving theory and observation the underwater noise from impact pile driving is studied using a finite element model for the sound generation and parabolic equation model for propagation results are compared with measurements using a vertical line array deployed at a marine construction site in puget sound it is shown that the dominant underwater noise from impact driving is from the mach wave associated with the radial expansion of the pile that propagates down the pile after impact at supersonic speed the predictions of vertical arrival angle associated with the mach cone peak pressure level as function of depth and dominant features of the pressure time series compare well with corresponding field observations

high resolution 3d laser scanner measurements of a strike slip fault quantify its morphological anisotropy at all scales 1 the surface roughness of a recently exhumed strike slip fault plane has been measured by three independent 3d portable laser scanners digital elevation models of several fault surface areas from 1 m2 to 600 m2 have been measured at a resolution ranging from 5 mm to 80 mm out of plane height fluctuations are described by non gaussian distribution with exponential long range tails statistical scaling analyses show that the striated fault surface exhibits self affine scaling invariance with a small but significant directional morphological anisotropy that can be described by two scaling roughness exponents h1 0 7 in the direction of slip and h2 0 8 perpendicular to the direction of slip

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

reprint of bedrock fault scarp history insight from t lidar backscatter behaviour and analysis of structure changes abstract this paper provides a research approach and develops a methodology that helps natural weathered bedrock fault scarps to be understood in terms of their structural changes and backscatter behaviour when using terrestrial laser scanning t lidar we tested our approach on the pisia fault in greece that ruptured during the 1981 alkyonides earthquake sequence in corinth gulf the method describes how to correlate fault geometry and structural variations with the backscatter signal of t lidar data from naturally exhumed bedrock fault scarps using this method we are able to reconstruct the past slip history we used t lidar for the analysis of the monochromatic laser beam s backscattered signal to define unsupervised classes of unknown objects on fault surface seven classes were created based on the dendrogram technique using the maximum likelihood method these were used to determine their spatial distribution throughout the scarp height and to calculate the terrain ruggedness index tri in the defined classes the combination of these results shows that i the ruggedness increases with the scarp height and ii the ruggedness and backscattering describe different fault plane conditions we found evidence for past earthquakes on the pisia fault at our study site with average displacements in the range of 30 60 cm with corresponding magnitudes of 6 4 6 6 0 1 ms these results help to reconstruct the recent fault history and potential palaeo events and can also be used i to detect appropriate sample sites on the fault plane for absolute dating and ii as an independent constraint on tracing slip events assisting absolute dating techniques this method can significantly reduce the sampling requirements and costs of cosmogenic absolute dating techniques overall it might be a valuable tool for extracting data regarding the faulting history and slip events for defining seismic hazard parameters

a rough guide to limestone fault scarps abstract the surface roughness of limestone fault scarps in central greece is examined with the aim of relating variations in rock weathering to palaeoseismic activity the study employs a micro roughness meter mrm and a carpenter s profile gauge to collect field measurements of scarp roughness presenting the results in terms of roughness indices which permit comparison between different height levels of a scarp the study confirms the increasing degradation of scarps with height thereby inferring the time dependent evolution of fault scarp roughness in addition roughness indices are found to discriminate between fault surfaces exposed during the 1981 corinth earthquakes and those emergent prior to this event

beam forming of the underwater sound field from impact pile driving observations of underwater noise from impact pile driving were made with a vertical line array previous studies reinhall and dahl j acoust soc am 130 1209 1216 2011 show that the dominant underwater noise from impact driving is from the mach wave associated with the radial expansion of the pile that propagates down the pile at supersonic speed after impact here precise estimates of the vertical arrival angles associated with the down and up going mach wave are made via beam forming and the energy budget of the arrival structure is quantified

characterization of fault roughness at various scales implications of three dimensional high resolution topography measurements accurate description of the topography of active fault surfaces represents an important geophysical issue because this topography is strongly related to the stress distribution along fault planes and therefore to processes implicated in earthquake nucleation propagation and arrest to date due to technical limitations studies of natural fault roughness either performed using laboratory of field profilometers were obtained mainly from 1 d profiles with the recent development of light detection and ranging lidar apparatus it is now possible to measure accurately the 3 d topography of rough surfaces with a comparable resolution in all directions both at field and laboratory scales in the present study we have investigated the scaling properties including possible anisotropy properties of several outcrops of two natural fault surfaces vuache strike slip fault france and magnola normal fault italy in limestones at the field scale digital elevation models of the fault roughness were obtained over surfaces of 0 25 m2 to 600 m2 with a height resolution ranging from 0 5 mm to 20 mm at the laboratory scale the 3 d geometry was measured on two slip planes using a laser profilometer with a spatial resolution of 20 m and a height resolution less than 1 m

normal faulting and crustal deformation alkyonides gulf and perachora peninsula eastern gulf of corinth rift greece geophysical structural geochronological and geomorphological data indicate that the psatha east alkyonides skinos and pisia faults are holocene active structures whereas the status of the west alkyonides strava perachora and loutraki faults is less certain we see no evidence for significant lateral surface fault growth new data for late pleistocene footwall uplift of the psatha fault are comparable with previously estimated holocene rates pre holocene stratigraphic sequences in the alkyonides gulf allow calculation of vertical displacement on the skinos fault of 1 42 1 60 km over a period of 0 6 ma previous palaeoseismological studies indicate comparable displacement rates extrapolated to 0 61 2 20 ma whereas extrapolation of previous geodetic data indicate a range of 0 17 0 46 ma the latter is too short given the evidence of the stratigraphic record signifying either that these data may not be representative of longer term rates or that significant deformation has taken place elsewhere for example on offshore antithetic faults a case is established for uniform late quaternary post mis 7 uplift of the perachora peninsula at rates of c 0 2 0 3 mm a 1 the lack of regional tilting over perachora corinth isthmia is in marked contrast to the situation in the alkyonides megara basins to the east

non planarity scale dependent roughness and kinematic properties of the pidima active normal fault scarp messinia greece using high resolution terrestrial lidar data abstract terrestrial lidar tls photogrammetric and field data were collected during the years 2014 2015 and 2017 at a 20 m long limestone scarp locality along the n s striking 70 west dipping active pidima fault messinia sw peloponnese greece this locality presents an artificially exhumed portion of an active fault plane thus providing a unique opportunity to study kinematics and limestone scarp morphology including its curvature and roughness the survey of 2015 offered a high density point cloud of the fault scarp with 6 mm working resolution creating a very close to real life representation 3d model we found that scarp geometry is non planar with increasing convexity up dip and increasing northwesterly dip directions from north towards south along strike non planarity is also recorded from the morphological data along strike with the appearance of several slip parallel troughs and ridges with a mean distance half wavelength of 0 75 m the fault plane roughness absolute values is scale dependent the roughness configuration attains a slip parallel pattern for observation scales above 1 cm at observations scales less than 1 cm a slip normal pattern is weakly visible the obtained tls results agree with field data manual compass measurements and macroscopic observations we infer an earthquake magnitude of 6 2 0 2 for the last event along the pidima fault based on the measured thickness of the smooth stripe that was imaged by t lidar along the non exhumed surface of the scarp

slip history of the magnola fault apennines central italy from 36cl surface exposure dating evidence for strong earthquakes over the holocene to better understand the mechanics of deformation in the mediterranean and the role that the convergence between africa and europe plays it is necessary to know the deformation field at different time scales here we use in situ 36 cl surface exposure dating of exposed bedrock fault scarps to determine earthquake time slip histories and to quantify slip rates over the last several thousand years this information allows us to delineate the seismic history of normal faulting within the mediterranean area over that time period we have studied the limestone scarp produced by the magnola fault in the central apennines italy the magnola fault in the fucino area is an active 15 km long normal fault striking wnw and dipping ssw the range front morphology characterised by steep triangular facets separated by v shaped valleys and wine glass canyons suggests that the magnola fault has been active for at least the last several hundred thousand years at the base of the facets the fault cuts limestone bedrock to produce a well preserved normal fault scarp 10 to 12 m high the distribution of 36 cl concentration versus the height along that scarp is best explained by a minimum of five and a maximum of seven successive earthquake exhumations with slips varying between 1 5 and 3 m an age of 5 ka at the base of the scarp and of 12 ka at the top yields a slip rate of 0 8 mm year the absence of any event on this fault during the last 5000 years suggests either that a future event is imminent on the magnola fault or that the fault has entered a quiescent period with

the underwater sound field from vibratory pile driving underwater noise from vibratory pile driving was observed using a vertical line array placed at range 16 m from the pile source water depth 7 5 m and using single hydrophones at range 417 m on one transect and range 207 and 436 m on another transect running approximately parallel to a sloping shoreline the dominant spectral features of the underwater noise are related to the frequency of the vibratory pile driving hammer typically 15 35 hz producing spectral lines at intervals of this frequency the mean square pressure versus depth is subsequently studied in third octave bands depth and frequency variations of this quantity observed at the vertical line array are well modeled by a field consisting of an incoherent sum of sources distributed over the water column adiabatic mode theory is used to propagate this field to greater ranges and model the observations made along the two depth varying transects the effect of shear in the seabed although small is also included bathymetric refraction on the transect parallel to the shoreline reduced mean square pressure levels at the 436 m measurement site

comparison of surface slip and focal mechanism slip data along normal faults an example from the eastern gulf of corinth greece abstract focal mechanism and surface slip data are used to investigate whether kinematics are similar at depth and at the surface along an active normal fault in the gulf of corinth greece we present a new database of slip data from the lateral termination of the south alkyonides fault segment safs and the en echelon stepover between it and an adjacent fault and use published data on surface slip and focal mechanism data pertaining to slip at depth during the 1981 alkyonides earthquake sequence the focal mechanisms exhibit similar fault plane orientations and kinematics to those measured at the surface within the stepover both data sets show that contemporaneous c n s and c e w extension is being accommodated by c e w and c n s oriented normal faults and the overall deformation is distributed oblate vertical flattening the deviation of the surface slip direction from 350 increases with distance from the centre of the safs the deviation of the focal mechanism t axes from 350 fit well with the surface data implying that the coseismic slip on the safs at depths of 7 10 km exhibits a similar kinematic pattern as that observed at the surface our results imply that it is critical to know the along strike position of data on a fault if either focal mechanisms or surface slip are to be used to infer regional strain and stress trajectories

a fault scarp in an urban area identified by lidar survey a case study on the itoigawa shizuoka tectonic line central japan abstract a light detection and ranging lidar survey was conducted in a densely built up area to generate a high resolution digital elevation model dem to look for active faults the urban district of matsumoto city in central japan is located in a 3 km 2 basin along the itoigawa shizuoka tectonic line active fault system one of japanese onshore fault systems with the highest earthquake probability a high resolution dem at a 0 5 m grid interval was obtained after removing the effects of laser returns from buildings clouds and vegetation it revealed a continuous scarp up to 2 m in height borehole data and archaeological studies indicate the scarp was formed during the most recent faulting event associated with historical earthquakes in addition the fault scarp strongly supports that the urban district is in a pull apart basin related to a fault step over between two left lateral strike slip faults consequently accurate interpretation of fault geometry is crucial to provide estimates of future surface deformation and to allow modeling of basin structure and strong ground motion thus the lidar mapping survey in urban districts is effective for detailed active fault mapping in order to constrain basin structure and to forecast the exact location of surface rupturing associated with large earthquakes

segment linkage process at the origin of slip surface roughness evidence from the dixie valley fault the dynamics and geometry of slip along a fault govern the distribution of heterogeneities and inturn these heterogeneities organize slip some of these heterogeneities are morphological and are fossilized in the topography of the fault plane i e its roughness in the present study our goal is to gain a better understanding of the processes involved during the creation and destruction of fault roughness our analysis is focused on the dixie valley nevada normal fault which has a particular outcrop that offers the opportunity to characterize the relationship between fault surface geometry and fault zone internal architecture the fault morphology was measured in the field using a light detection and ranging lidar apparatus the data indicate that the fault surface topography is self affine and characterized by two power law exponents one parallel h 0 6 and one perpendicular ht 0 8 to the slip direction accordingly self affinity implies that the fault surface appears smoother as the spatial scale increases more precisely this self affine property indicates that the standard deviation of the roughness amplitude scales as l 0 6 where l is the distance along the fault in the slip direction we propose that fault roughness generation is dominated by damage processes that leave an imprint on fault geometry in the form of elongated lenses indeed the fault zone displays a network of anastomosed discrete slip surfaces that bound bumpy lenses of damaged rock elongated in the direction of slip and that give the fault a rough topography such lenses are also observed in many other faults worldwide symmetry axis measurements of the lenses found in the dixie valley fault reveal that their geometry is scale dependent the maximum thickness t of the lenses scales with their length l measured in the slip direction as tfl 0 6 based on previous experimental studies on the fault growth process we suggest that the multiscale aggregation of lenses explains why the standard deviation of the roughness amplitude of the fault surface scales as l 0 6 we propose that elastic interactions related to the linkage of many discrete slip surfaces controlling the generation of multi scale bumpy lenses are one of the physical processes at the

motion on the kaparelli fault greece prior to the 1981 earthquake sequence determined from 36cl cosmogenic dating in february and march 1981 three successive destructive earthquakes occurred at the eastern end of the gulf of corinth the third shock march 4 ms 6 4 ruptured the kaparelli fault about 40 cm of a limestone fault scarp was exhumed by the earthquake each major prehistoric earthquake has added new surface to this cumulative scarp exposing fresh material to cosmic ray bombardment using 36cl cosmic ray exposure dating we have obtained the continuous exposure history for this 4 5 m high limestone surface at two sites about 50 m apart the results suggest that the kaparelli fault has ruptured three times prior to 1981 at 20 3 ka 14 5 0 5 ka and 10 5 0 5 ka with slip amplitudes between 0 6 m and 2 1 m the kaparelli fault appears to have been inactive for 10 thousand years prior to the 1981 event

palaeoseismology historical and prehistorical records of earthquake ground effects for seismic hazard assessment given the tremendous toll in human lives and attendant economic losses it is appropriate that scientists are working hard to understand better earthquakes with the aim of forecasting and ultimately predicting them in the last decades increasing attention has been paid to the coseismic effects on the natural environment creating a solid base of empirical data for the estimation of source parameters of strong earthquakes based on geological observations the recently introduced inqua scale environmental seismic intensity esi 2007 scale of macroseismic intensity clearly shows how the systematic study of earthquake surface faulting coseismic liquefaction tsunami deposits and other primary and secondary ground effects can be integrated with traditional seismological and tectonic information to provide a better understanding of the seismicity level of an area and the associated hazards at the moment this is the only scientific means of equating the seismic records to the seismic cycle time spans extending the seismic catalogues even to tens of thousands of years improving future seismic hazard analyses this special publication covers some of the latest multidisciplinary work undertaken to achieve that aim eighteen papers from research groups from all continents address a wide range of topics related both to palaeoseismological studies and assessment of macroseismic intensity based only on the natural phenomena associated with an earthquake

the tectonic geomorphology of bedrock scarps on active normal faults in the italian apennines mapped using combined ground penetrating radar and terrestrial laser scanning using combined datasets from ground penetrating radar gpr and terrestrial laser scanning tls we document the variety of tectono geomorphic features that contribute to the morphology of bedrock scarps associated with active extensional faulting in central italy measurement of faulted offsets across such scarps can provide important fault slip rate data relevant to seismic hazard analysis if ages can be established for offset features however interpretation of these offsets is challenging when geomorphic processes as well as fault slip contribute to exhumation of the bedrock during scarp development through the integration of surface tls and subsurface gpr datasets we show that the surface expression of three bedrock scarps results from the interaction between footwall incision hangingwall sedimentation channel incision and landsliding as well as fault slip and fault linkage we further illustrate how these processes can be differentiated to identify locations suitable for determining fault slip rates the identification of such features has important implications for our understanding of the relationship between bedrock faulting and geomorphic processes in turn contributing to improved assessment of fault slip rates in the central apennines the use of combined gpr and tls datasets here has shown that the tectono geomorphic features of the studied scarps vary greatly over short distances and we emphasise the need for detailed scarp analysis to elucidate the processes responsible for bedrock exhumation before estimating the rates of fault slip over the timescale of scarp formation

on the underwater sound field from impact pile driving arrival structure precursor arrivals and energy streamlines underwater noise from impact pile driving is studied through measurements using a vertical line array vla placed at range 120 m from the pile source water depth 7 5 m over which bathymetry varied gradually increasing to depth 12 5 m at the vla the data were modeled assuming the pile impact produces a radial expansion that acts as sound source and propagates along the pile at supersonic speed this leads to the conceptualization of the pile as a discrete vertical line source for which frequency and source depth dependent complex phasing is applied dominant features of the pressure time series versus measurement depth are reproduced in modeled counterparts that are linearly related these observations include precursor arrivals for which arrival timing depends on hydrophone depth and influence of a sediment sound speed gradient on precursor amplitude spatial gradients of model results are taken to obtain estimates of acoustic particle velocity and vector intensity for which active intensity is studied in the time domain evaluation of energy streamlines based on time integrated active intensity and energy path lines based on instantaneous or very short time integrated active intensity reveal interesting structure in the acoustic field including an inference as to the source depth of the precursor

validation of finite element computations for the quantitative prediction of underwater noise from impact pile driving the acoustic radiation from a pile being driven into the sediment by a sequence of hammer strikes is studied with a linear axisymmetric structural acoustic frequency domain finite element model each hammer strike results in an impulsive sound that is emitted from the pile and then propagated in the shallow water waveguide measurements from accelerometers mounted on the head of a test pile and from hydrophones deployed in the water are used to validate the model results transfer functions between the force input at the top of the anvil and field quantities such as acceleration components in the structure or pressure in the fluid are computed with the model these transfer functions are validated using accelerometer or hydrophone measurements to infer the structural forcing a modeled hammer forcing pulse is used in the successive step to produce quantitative predictions of sound exposure at the hydrophones the comparison between the model and the measurements shows that although several simplifying assumptions were made useful predictions of noise levels based on linear structural acoustic models are possible in the final part of the paper the model is used to characterize the pile as an acoustic radiator by analyzing the flow of acoustic energy 2013 acoustical society of america

geomorphology of active faulting and seismic hazard assessment new tools and future challenges by witold zuchiewicz and jerzy zasadni 2012 intended for this volume young tectonics of the outer western carpathians in the light of some morphometric indices in this paper we test the applicability of some morphometric indices commonly used in tectonic geomorphological studies to the area of the outer western carpathians representing an alpine fold and thrust belt this belt was shaped largely in miocene times and shows traces of pliocene quaternary tectonic activity consisting mainly in some remnant folding and faulting this is indicated by scarce examples of faulting within quaternary strata numerous cases of clast fracturing owing to palaeoearthquakes of relatively large magnitudes as well as warping and tilting of pleistocene and holocene strath terraces analysis of selected morphometric indices valley floor width valley height ratio riverbed gradients stream length gradient index basin elongation ratios and others conducted for the entire region and some chosen test areas in the westernmost part of the outer western ac c ep te d m an u sc r ip t accepted manuscript 24 carpathians proved their usefulness in detecting zones showing tendencies to young surface uplift however in the case of the stream length gradient index sl hack s index a word of caution should be added since the index is extremely sensitive to lithologic contrasts in the bedrock and its applicability to young tectonic analysis of fold and thrust belts appears to be strongly limited dr andrzej piotrowski apiot pgi gov pl szczecinie panstwowy instytut geologiczny szczecin poland and dr klaus reicherter rwth aachen university germany

faults smooth gradually as a function of slip abstract geometry and roughness of fault surfaces plays a central role in the dynamics and kinematics of faulting faults smooth with increasing slip but the degree of the smoothing has not previously been well constrained for natural faults we measure the roughness as a function of displacement for a suite of 16 faults with cumulative offsets ranging from 0 1 m to approximately 500 m we find that slip parallel roughness evolves gradually with slip for instance for segments of length 0 5 m h 2 10 3 d 0 1 where h is the rms roughness and d is the displacement on the fault strand with both quantities measured in meters the gradual nature of the smoothing is robust to varying lithology and erosion the weak function implies a decrease in the rate of gouge formation for a model with increasing slip for a model in which gouge is generated by abrading an asperity tip the relatively gradual evolution of roughness could be explained by lubrication by the accumulated gouge that mitigates the abrasional smoothing that occurs during slip and or re roughening processes

heightened odds of large earthquakes near istanbul an interaction based probability calculation we calculate the probability of strong shaking in istanbul an urban center of 10 million people from the description of earthquakes on the north anatolian fault system in the marmara sea during the past 500 years and test the resulting catalog against the frequency of damage in istanbul during the preceding millennium departing from current practice we include the time dependent effect of stress transferred by the 1999 moment magnitude m 7 4 izmit earthquake to faults nearer to istanbul we find a 62 15 probability one standard deviation of strong shaking during the next 30 years and 32 12 during the next decade

spatial and temporal variations in growth rates along active normal fault systems an example from the lazio abruzzo apennines central italy abstract the geometry kinematics and rates of active extension in lazio abruzzo italian apennines have been measured in order to gain a better understanding of the spatial and temporal variations in fault growth rates and seismic hazards associated with active normal fault systems we present fault map traces throws throw rates and slip directions for 17 parallel en echelon or end on active normal faults whose 20 40 km lengths combine to form a soft linked fault array ca 155 km in length and ca 55 km across strike throw rates derived from observations of faulted late glacial features and holocene soils show that both maximum throw rates and throw rate gradients are greater on centrally located faults along the strike of the array total throws and throw gradients show similar spatial variations but with weaker relationships with distance along strike when summed across strike throw rates are increasingly high towards the centre of the array relative to summed throws we interpret the above to suggest that throw rates have changed in the recent past ca 0 7 ma from spatially random fault growth rates initiating at 2 5 3 3 ma to growth rates that are greater on centrally located faults we interpret this as evidence for fault interaction producing throw rate variations that drive throw profile readjustment on these crustal scale soft linked faults the results are used to discuss seismic hazards in the region which are quantified in a second paper in this issue

extensional fault cores in micritic carbonate case studies from the gulf of corinth greece abstract the major pisia and doumena faults of the corinth rift greece are both hosted by micritic carbonate rock their common fault elements are principal slip surfaces layers of fault rocks fault rock and host rock lenses corrugations and smaller shear and tension fractures along planar fault segments a corrugated slip surface with an associated thin fault rock layer is formed well developed down dip corrugations indicate movement along the same surface over many fault increments bends jogs in the faults are sites of complex structural relations hosting frequent lenses more porous fault rocks and dense networks of fractures major jogs in the slip surfaces have both strike and dip oriented undulating curvature that are associated with higher order fracture networks as well as frequent lenses fault core lens shapes of the doumena fault show relationship of length vs width of 3 2 similarly principal slip surfaces of the two faults show undulations with aspect ratios of amplitude vs wavelength 1 19 and 1 14 in strike direction despite a prominent difference in down dip geometry the intrinsic deformation in fault cores of micritic carbonate supports a model in which fluids entered the core by damage zone fractures that are linked to the principal slip surface flow along the fault core was controlled by the fracture system of lenses and thereby lens connectivity but may have been hampered by flow retarding fault rocks the flow potential is especially well developed in fault bends and breached relays due to frequent lenses and well developed fracture networks