problems in identifying the effects of structure and critical state in a soil with a transitional behaviour this work shows that some soils with an intermediate behaviour between clays and sands do not have a unique compression line as has also been pointed out by martins et al it has been shown here that a unique critical state line could not be determined for the remoulded soil although the results shown here are for a reconstituted residual soil similar behaviour in compressibility has been found in silts and mixtures of sand and kaolin however it has been found that the critical state framework can be applied using a family of parallel critical state lines depending on the initial specific volume one of the questions raised by this work is how the effects of structure can be quantified if the intrinsic properties of the remoulded material are not unique the compression and critical state lines of the remoulded material are not only non unique but also of a distinctly different gradient from the natural material

effect of fabric on the behaviour of reservoir sandstones a laboratory investigation was undertaken on the mechanical behaviour of two sandstones that are commonly used as analogous hydrocarbon reservoir sandstones using triaxial apparatuses with a capacity of up to 70 mpa confining pressure both materials are lightly cemented but show a mechanical behaviour at large strains that is similar to that seen in rocks with much stronger cementation at small strains however these materials behave more like uncemented sands in that they show a strong stress dependency of the shear modulus and yield takes places at relatively small strains it is believed that fabric plays a fundamental role in the observed behaviour and this is supported by the experimental evidence so that the concept of strong fabric in sandstones is introduced

oblique slip on the puysegur subduction interface in the 2009 july mw 7 8 dusky sound earthquake from gps and insar observations implications for the tectonics of southwestern new zealand summary the mw 7 8 dusky sound earthquake of 2009 july 15 was the largest earthquake in new zealand in the past 80 yr and is the only major subduction interface earthquake in the new zealand historical record we have estimated the coseismic and early post seismic slip distribution in the earthquake by inversion of gps and differential interferometric synthetic aperture radar dinsar observations we show that slip during the earthquake was highly obliqueandessentiallyintheaustralia pacificrelativeplatemotiondirection failureoccurred onaca 80by50kmpatchofthesubductioninterfacewithmaximumslip5 6m inthisregion the offshore alpine fault carries up to 30 mm yr 1 of slip before terminating at resolution ridge near the southern end of the 2009 slip patch the southernmost part of the alpine fault trace lies near the up dip end of the 2009 slip patch and the fault probably exists only within the crust of the over riding plate in this region terminating at shallow depth where it meets the subduction interface there is no evidence for rupture of the alpine fault during the 2009 event however coulomb stress changes from the subduction earthquake have brought this section of the alpine fault closer to failure in contrast to many subduction zones undergoing oblique subduction where the slip in major earthquakes is partitioned into more or less pure thrustearthquakesonthesubductioninterfaceandstrike slipearthquakesinthebackarc thisis a case where the majority of the subduction interface slip is not partitioned with only a shallow convergence zone west of the strike slip alpine fault undergoing contraction approximately normal to subduction zone strike north of the 2009 earthquake region the alpine fault lies further east relative to the subduction interface and partitioning between strike slip on the alpine fault and trench normal thrusting on the subduction interface takes place in a more typical fashion our results provide the first clear demonstration of non partitioned oblique slip between the australian and pacific plates offshore of southern new zealand

three dimensional surface displacements during the 2016 m w 7 8 kaikōura earthquake new zealand from photogrammetry derived point clouds

the mechanics of an italian silt an example of transitional behaviour by controlling the particle size distribution of an italian silt the influence of grading on its behaviour was investigated as the clay content was reduced the behaviour changed from a typical clay mode to a transitional form between that of clays and sands that had previously been seen only for gap graded soils emphasising that this type of behaviour is possibly much more extensive than previously thought the work has highlighted several features of transitional behaviour and in particular that unique normal compression and critical state lines do not exist that rendulic s principle does not apply and that drained and undrained tests do not reach unique ultimate states

surface rupture during the 2010 mw 7 1 darfield canterbury earthquake implications for fault rupture dynamics and seismic hazard analysis the september 2010 m w 7 1 darfield canterbury earthquake in new zealand is one of the best recorded earthquakes of this magnitude the earthquake occurred on a previously unidentified fault system and generated a 29 5 0 5 km long surface rupture across a low relief agricultural landscape high accuracy measurements of coseismic displacements were obtained at over 100 localities along the greendale fault maximum net displacement d max 5 3 0 5 m and average net displacement d avg 2 5 0 1 m are anomalously large for an earthquake of this m w d max surface rupture length srl and d avg srl ratios are among the largest ever recorded for a continental strike slip earthquake geologically derived estimates of moment magnitude m w g are less than the seismologically derived m w derived using widely employed srl m w scaling regressions m w g is greater than m w using d max and d avg m w regressions the geologically derived static stress drop of 13 9 3 7 mpa provides a context with which to compare this earthquake rupture to interplate and intraplate ruptures of similar m w this data set provides fundamental information on fault rupture processes relevant to seismic hazard modeling in this region and analogous settings globally

the 2002 denali fault earthquake alaska a large magnitude slip partitioned event the mw moment magnitude 7 9 denali fault earthquake on 3 november 2002 was associated with 340 kilometers of surface rupture and was the largest strike slip earthquake in north america in almost 150 years it illuminates earthquake mechanics and hazards of large strike slip faults it began with thrusting on the previously unrecognized susitna glacier fault continued with right slip on the denali fault then took a right step and continued with right slip on the totschunda fault there is good correlation between geologically observed and geophysically inferred moment release the earthquake produced unusually strong distal effects in the rupture propagation direction including triggered seismicity

surface slip and off fault deformation patterns in the 2013 mw 7 7 balochistan pakistan earthquake implications for controls on the distribution of near surface coseismic slip comparison of 398 fault offsets measured by visual analysis of worldview high resolution satellite imagery with deformation maps produced by cosi corr subpixel image correlation of landsat 8 and spot5 imagery reveals significant complexity and distributed deformation along the 2013 mw 7 7 balochistan pakistan earthquake average slip along the main trace of the fault was 4 2 m with local maximum offsets up to 11 4 m comparison of slip measured from offset geomorphic features which record localized slip along the main strand of the fault to the total displacement across the entire width of the surface deformation zone from cosi corr reveals 45 off fault deformation while previous studies have shown that the structural maturity of the fault exerts a primary control on the total percentage of off fault surface deformation large along strike variations in the percentage of strain localization observed in the 2013 rupture imply the influence of important secondary controls one such possible secondary control is the type of near surface material through which the rupture propagated we therefore compared the percentage off fault deformation to the type of material bedrock old alluvium and young alluvium at the surface and the distance of the fault to the nearest bedrock outcrop a proxy for sediment thickness along this hybrid strike slip reverse slip fault we find significantly more off fault deformation in younger and or thicker sediments accounting for and predicting such off fault deformation patterns has important implications for the interpretation of geologic slip rates especially for their use in probabilistic seismic hazard assessments the behavior of near surface materials during coseismic deformation and the future development of microzonation protocols for the built environment

surface slip during large owens valley earthquakes data sets and expanded results contributing to this study are available in the supporting information the earthscope southern and eastern california lidar project available online at http opentopo sdsc edu involved data acquisition and processing for the plate boundary observatory pbo by ncalm http www ncalm org unavco operates the pbo for earthscope http www earthscope org supported by the national science foundation ear 0350028 and ear 0732947 funding for this study was provided by the southern california earthquake center scec project 12140 the geological society of america graduate student research fund the community foundation of san bernardino county and the western washington university geology department we thank g seitz m price and k morgan for assistance in the field and s bacon j arrowsmith r weldon k scharer j unruh c madden madugo and d haddad for helpful discussions constructive reviews by d schwartz r briggs e schermer d clark and one anonymous reviewer substantially improved the paper we also thank the staff at the uc white mountain research center for facilitating this work any use of trade firm or product names is for descriptive purposes only and does not imply endorsement by the u s government

estimation of the compression behaviour of reconstituted clays abstract the void index is a relative quantity measuring the position of the current void ratio of a clay against the void ratios of the clay at two specific vertical effective stresses i e v 100 kpa and v 1000 kpa based on this concept a simple systematic tool is proposed for estimating the compression behaviour of reconstituted clays over a wide range of stresses and water contents following the practice of geotechnical engineering computation the compression behaviour of clays is idealised as linear segments in the iv lnp or the void index and the mean effective stress space considering the variation in the available data there are three related but independent models for describing the compression behaviour of reconstituted clays the accuracy of estimation increases with the level of available data the proposed estimation is used to simulate the behaviour of a variety of reconstituted clays over a wide range of stresses and water contents with different levels of available data the estimation is evaluated on the basis of these simulations the proposed estimation can take maximum use of available data and provide a simple yet practical tool for calculating the compression behaviour of reconstituted clays and a basic parameter for geotechnical engineering computations the compression index an empirical equation for the initial compression index is also suggested and verified

strength of weakly cemented sands from drained multistage triaxial tests characterizing the strength of weakly cemented and sensitive soils in the laboratory is difficult because of the difficulty in obtaining high quality replicate samples necessary for defining the failure envelope multistage triaxial tests have long been used to reduce the variability caused by testing multiple samples however traditional criteria used for transitioning from one loading stage to another often lead to destructuring or failure in sensitive or structured soils the objective of this paper is to present a methodology for conducting multistage drained triaxial tests on weakly cemented sands and estimating the resulting shear strength parameters both multistage and single stage drained triaxial tests were performed on artificially cemented samples of a silty sand at two levels of densities and cementation the use of dev dea 0 as a termination criterion to move on to the next stage of loading and ev 0 as the failure criterion for the final stage of the shear resulted in an average error of 6

the mechanics of uncemented carbonate sands the mechanical behaviour of a typical biogenic carbonate sand was investigated using triaxial testing at standard and also at high pressures up to 8 mpa the test results show that despite the particle breakage which is characteristic of these soils their behaviour is still qualitatively similar to that observed for more commonly encountered soils and is consistent with the principle features of critical state soil mechanics the higher stresses used in these tests were an order of magnitude greater than are generally used in soils testing and the values of some individual soil parameters were found to be outside the range of normal experience micrographic and gradings analyses were used to examine the influence of isotropic and shear stresses on particle breakage triaxial test results illustrate the influence of this breakage on the mechanical behaviour of the soil le comportement mecanique d un sable carbonate biogenique typique a ete etudie par des essais triaxiaux a pression normale et aussi a d

high resolution relocation of aftershocks of the mw 7 1 darfield new zealand earthquake and implications for fault activity 1 low slip rate regions often represent under recognized hazards and understanding the progression of seismicity when faults in such areas rupture will help us to better understand earthquake rupture patterns the 3 september 2010 utc mw 7 1 darfield earthquake revealed a formerly unrecognized set of faults in the canterbury region of new zealand an area that had previously been mapped as one of the lower hazard areas in the country in this study we analyze the first four months of its aftershock sequence to identify active faults and temporal changes in seismicity along them we jointly invert for three dimensional p wave and s wave velocities and hypocentral locations using data for 2840 aftershocks recorded at 36 temporary and permanent seismic stations within 70 km of the main shock epicenter these relocations delineate eight individual faults active prior to the 22 february 2011 mw 6 3 christchurch earthquake the largest aftershock of the darfield earthquake two of these faults are in the christchurch region one of which corresponds to geodetically determined rupture planes of the christchurch earthquake using focal mechanisms calculated from first motion polarities we find mainly strike slip faulting events with some reverse and normal faulting events as well we compare the orientations of these faults to the prevailing regional stress directions to identify which faults may have been active prior to the darfield earthquake and which may be newly developed

influence of grading on the mechanical behaviour of stava tailings tailings dams can be fragile structures and too often they are subject to liquefaction the material they are composed of is rather peculiar having a man made origin and their behaviour is still not very well understood the soil from the stava tailings dams structures that were subject to liquefaction in 1985 causing extensive destruction was investigated in this study as an example of tailings two main aspects of their behaviour have been examined the influence of the percentage of silt and sand that compose the soil on its mechanical behaviour and the susceptibility to liquefaction analysing the behaviour within a critical state framework in this paper it is shown that as the quantity of silt increases the slope and intercept of the normal compression line and critical state line at higher pressures decrease until an inversion of behaviour is observed while at lower stress levels the critical state line changes its position but not its slope this means that the effect of adding silt on the

the undrained cyclic behaviour of a carbonate sand a series of undrained cyclic triaxial tests was carried out on a carbonate sand that had previously been the subject of extensive research for monotonic loading it was found that the generation of

surface rupture and slip distribution along the karadere segment of the 17 august 1999 izmit and the western section of the 12 november 1999 duzce turkey earthquakes on 17 august 1999 the mw 7 5 i zmit turkey earthquake produced surface rupture in excess of 120 km and perhaps as much as 200 km with up to 5 m of dextral slip along a western portion of the north anatolian fault zone the 12 november 1999 mw 7 1 duzce turkey earthquake produced a 40 km long sur face rupture including 9 km of rupture overlap with the eastern end of the august event our mapping focused on the 40 km long karadere rupture segment the east ernmost segment of the august event as well as on the western 20 km of the no vember rupture maximum dextral slip along the karadere segment is approximately 1 5 m and the average slip on this segment is close to 1 m although slip along the karadere segment is considerably less than that on segments to the west this segment is of particular interest for three reasons 1 the western boundary of the karadere segment is defined by the most striking structural discontinuity along the entire au gust surface rupture i e a 5 km wide zone of no surface rupture as well as a 25 change in trend from e w to ene and such a discontinuity may have important implications for rupture dynamics 2 surface rupture terminates at the east end of the karadere rupture segment at a 1 5 to 3 km wide extensional step over at eften lake and 3 the 12 november 1999 duzce earthquake reruptured the easternmost 9 km of the karadere segment raising interesting questions about rupture dynamics and interactions between events on adjacent fault segments the details of the 17 august 1999 and l2 november 1999 surface rupture traces suggest that rupture may have partially propagated across the eften lake extensional step over although this step over seems to have acted as an effective barrier to rupture propagation

near field deformation from the el mayor cucapah earthquake revealed by differential lidar large moment magnitude m w 7 continental earthquakes often generate complex multifault ruptures linked by enigmatic zones of distributed deformation here we report the collection and results of a high resolution nine returns per square meter airborne light detection and ranging lidar topographic survey of the 2010 m w 7 2 el mayor cucapah earthquake that produced a 120 kilometer long multifault rupture through northernmost baja california mexico this differential lidar survey completely captures an earthquake surface rupture in a sparsely vegetated region with pre earthquake lower resolution 5 meter pixel lidar data the postevent survey reveals numerous surface ruptures including previously undocumented blind faults within thick sediments of the colorado river delta differential elevation changes show distributed kilometer scale bending strains as large as 10 3 microstrains in response to slip along discontinuous faults cutting crystalline bedrock of the sierra cucapah

ground based and uav based photogrammetry a multi scale high resolution mapping tool for structural geology and paleoseismology this contribution reviews the use of modern 3d photo based surface reconstruction techniques for high fidelity surveys of trenches rock exposures and hand specimens to highlight their potential for paleoseismology and structural geology we outline the general approach to data acquisition and processing using ground based photographs acquired from standard dslr cameras and illustrate the use of similar processing approaches on imagery from unmanned aerial vehicles uavs it is shown that digital map and trench data can be acquired at ultra high resolution and in much shorter time intervals than would be normally achievable through conventional grid mapping the resulting point clouds and textured models are inherently multidimensional x y z point orientation colour texture archival and easily transformed into orthorectified photomosaics or digital elevation models dems we provide some examples for the use of such techniques in structural geology and paleoseismology while pointing the interested reader to free and commercial software packages for data processing visualization and 3d interpretation photogrammetric models serve to act as an ideal electronic repository for critical outcrops and observations similar to the electronic lab book approach employed in the biosciences this paper also highlights future possibilities for rapid semi automatic to automatic interpretation of the data and advances in technology

step over and bend structures along the 1999 duzce earthquake surface rupture north anatolian fault turkey the 12 november 1999 duzce earthquake m w 7 1 which occurred on the duzce fault of the north anatolian fault zone formed a 40 km long surface rupture which extended between golyaka in the west and kaynasli in the east the earthquake nucleated close to the beykoy step over a 0 8 km wide and 1 8 km long pressure ridge with bilateral rupture propagation both to the west and the east the beykoy kaynasli and cevizlik step overs through which the 1999 duzce rupture propagated are less than 2 5 km wide the eften and bakacak step overs where the rupture was arrested are more than 4 km wide these exceptional dimensions of step overs associated with the 1999 duzce rupture were investigated for their influ ence on rupture propagation the earthquake broke three distinct geometric segments from west to east the eften dagdibi and kaynasli fault segments separated by left restraining step overs at beykoy and kaynasli to the west of the main shock 3 5 m of average slip on the eften fault segment propagated into the 2 km wide cevizlik releasing double bend where it was largely arrested with smaller 0 5 m slip continuing westward on the golyaka intervening segment west of lake eften this is similar to the ter mination of slip observed on the karadere fault segment in the 1999 izmit earthquake where 1 5 m of slip was largely terminated by a releasing double bend at the golyaka intervening segment with minor slip continuing eastward near lake eften to the east of the main shock 5 m of slip decreased along the dagdibi fault segment to about 3 5 m at the 1 km wide kaynasli step over from here to the east the 2 5 m of average slip on the kaynasli fault segment continued to decrease reaching zero at the releasing step overs to the elmalik fault the terminations of the 1999 duzce surface rupture are defined by distinct struc tural complexities the rupture was arrested in the west at the 4 km wide eften releasing double bend where the eastern termination of the 1999 izmit rupture also occurred to the east the rupture terminated at the 4 to 5 km wide bakacak releasing double step overs both eastern and western ends of the duzce rupture have short fault segments that experienced minor rupture during the 1999 duzce earthquake the golyaka intervening segment experienced minor rupture during both the 1999 izmit and duzce earthquakes the duzce rupture propagated across 0 8 to 2 km wide step overs but it was arrested at step overs 4 km wide or wider these results agree with the observations on ratios between step over width in kilometers and strike slip displacement in meters collected along strike slip faults worldwide let tis et al 2002

revealing coseismic displacement and displacement partitioning at the northern end of the 1999 chi chi earthquake central taiwan using digital cadastral data abstract the 1999 chi chi taiwan earthquake m w 7 6 was the largest earthquake to strike taiwan in the twentieth century its surface rupture extends more than 100 km in a north south trend however the northern end of this surface deformation abruptly terminates at an area between the tachia river and the taan river where a broad pop up structure with east to northeast strike quite different from the north south striking main thrust is found this pop up structure is composed of several regions of parallel thrusts and back thrusts and total shortening reaches about 9 m in order to reveal the displacement field in the pop up structure and slip vectors of branch faults we use a digital cadastral system with about 17 000 control points to calculate coseismic displacement around the shihkang area the digital cadastral system was originally conceived to survey land and building boundaries the cadastral system affords high density control points that reach about 2800 points km 2 and the accuracy is to within 11 cm outside of the pop up structure the horizontal displacements vectors are 8 9 m in about 330 340 changing as they pass through the surface rupture the azimuth of horizontal displacement shows large variation with the azimuth from 360 to 315 and displacement amounts from about 4 8 m inside the pop up structure in addition according to these cadastral data we found surface ruptures that had not been observed in previous studies that could be of importance to future disaster assessment

developing sub 5 m lidar dems for forested sections of the alpine and hope faults south island new zealand implications for structural interpretations abstract kilometre wide airborne light detection and ranging lidar surveys were collected along portions of the alpine and hope faults in new zealand to assess the potential for generating sub 5 m bare earth digital elevation models dems from ground return data in areas of dense rainforest bush cover as an aid to mapping these faults the 34 km long franz whataroa lidar survey was flown along the densely vegetated central most portion of the transpressive alpine fault six closely spaced flight lines 200 m apart yielded survey coverage with double overlap of swath collection which was considered necessary due to the low density of ground returns 0 16 m 2 or a point every 6 m2 under mature west coast podocarp broadleaf rainforest this average point spacing 2 5 m allowed for the generation of a robust high quality 3 m bare earth dem the dem confirmed the zigzagged form of the surface trace of the alpine fault in this area originally recognised by norris and cooper 1995 norris and cooper 1997 and highlights that the surface strike variations are more variant than previously mapped the 29 km long hurunui hope lidar survey was flown east of the main divide of the southern alps along the dextral slip hope fault where the terrain is characterised by lower rainfall and more open beech forest flight line spacings of 275 m were used to generate a dem from the ground return data the average ground return values under beech forest were 0 27 m 2 and yielded an estimated cell size suitable for a 2 m dem in both cases the lidar revealed unprecedented views of the surface geomorphology of these active faults lessons learned from our survey methodologies can be employed to plan cost effective high gain airborne surveys to yield bare earth dems underneath vegetated terrain and multi storeyed canopies from densely forested environments across new zealand and worldwide

liquefaction of crushable soils crushable soils when sheared in a dense state have stress paths which are similar to those for loose hard grained sands however because of their angular nature they do not liquefy as easily under cyclic loading in the hyogo ken nambu 1995 earthquake there was widespread liquefaction of land areas reclaimed from the sea using a crushable highly angular decomposed granite soil masado which was previously regarded as a high quality fill material with little risk of liquefaction in earthquakes results are presented from monotonic and cyclic triaxial tests on three types of crushable soil namely masado shirasu volcanic sand and dogs bay carbonate sand together with standard silica toyoura sand to establish liquefaction criteria which can be applied not only to hard grained silica sands but also to more angular crushable sands in monotonic triaxial testing the stress paths passed through a point of phase transformation with each material exhibiting large strains after this point normalization

dynamic role of a westerly wind burst in triggering an equatorial pacific warm event abstract dynamical impacts of a strong westerly wind burst wwb are studied using an ocean atmosphere coupled simulation in which an intense westerly wind burst is introduced the ocean response includes local and remote components with the development of a zonal surface jet and the appearance of positive sea surface temperature anomalies in the eastern pacific as observed during the triggering of the 1997 98 el nino remote warming results from the eastward propagation of a subsurface temperature anomaly generated in the western pacific a detailed heat budget helps to describe and understand the major mechanisms taking part to the formation of the subsurface temperature anomaly in the western pacific contributing to its eastward propagation and leading to the surface warming simulated in the eastern pacific advective contributions are proved to be widely predominant in the heat budget further decomposition of advective terms into linear and nonlinear parts allows insights into the role of mean stat

defining fault avoidance zones and associated geotechnical properties using masw a case study on the springfield fault new zealand abstract the springfield thrust fault at dalethorpe west canterbury new zealand provides a test case to explore the correlation between shear wave velocities at a range of scales and direct field observations of distributed deformation and outcrop properties the springfield fault ruptures to the surface through hard torlesse greywacke overlain on a flight of late quaternary glacio fluvial terraces by 5 m of gravel fault slip has displaced all but the lowest terraces revealing the geometry and location of faulting we used multi channel analysis of surface waves and meter scale cross hole measurements to map shear wave velocities below the lowest apparently undisplaced terrace we correlated these surveys with geotechnical parameters measured at outcrops and investigated relationships in the laboratory both field and laboratory results indicate that the shear wave velocity of torlesse greywacke declines sharply with increasing fracture density field surveys further indicate that relatively unweathered high velocity greywacke is being exhumed in a bivergent wedge between two opposite facing thrusts the fracturing and low shear wave velocities are focused in a wide low velocity damage zone that has developed in the hanging wall of the main thrust and a smaller but similar feature in the hanging wall of the backthrust this is consistent with the geomorphology of the site our correlations of geomorphic indicators of deformation with fault zone velocity structure provide a useful method with which to characterize the distribution of cumulative strain this type of analysis has utility for land use planning on or close to active faults especially where they are obscured by fluvial deposits

fault kinematics and surface deformation across a releasing bend during the 2010 mw 7 1 darfield new zealand earthquake revealed by differential lidar and cadastral surveying dextral slip at the western end of the east west striking greendale fault during the 2010 m w 7 1 darfield earthquake transferred onto a northwest trending segment across an apparent transtensional zone here named the waterford releasing bend we used detailed surface mapping differential analysis of pre and postearthquake light detection and ranging lidar and property boundary cadastral resurveying to produce high resolution centimeter scale estimates of coseismic ground surface displacements across the waterford releasing bend our results indicate that the change in orientation on the greendale fault incorporates elements of a large scale releasing bend from the viewpoint of westward motion on the south side of the fault as well as a smaller scale restraining stepover from the viewpoint of southeastward motion on the north side of the fault these factors result in the waterford releasing bend exhibiting a decrease in displacement to near zero at the change in strike and the presence within the overall releasing bend of a nested localized restraining stepover with contractional bulging the exceptional detail of surface deformation and kinematics obtained from this contemporary surface rupture event illustrates the value of multimethod investigations our data provide insights into strike slip fault bend kinematics and into the potentially subtle but important structures that may be present at bends on historic and prehistoric rupture traces

the evolution of the sciara del fuoco subaerial slope during the 2007 stromboli eruption relation between deformation processes and effusive activity abstract focusing on the island of stromboli this research investigates whether airborne remote sensing systems such as those based on digital photogrammetry and laser scanner sensors can be adopted to monitor slope deformation and lava emplacement processes in active volcanic areas thanks to the capability of extracting accurate topographic data and working on flexible time schedules these methods can be used to constrain the regular and more frequent measurements derived from satellite observations this work is dedicated to the monitoring of stromboli s volcanic edifice which is beneficial when obtaining quantitative data on the geometry of deformation features and the displaced failures and landslides and emplaced lava flows volumes in particular we focus on the capability of extracting average effusion rates from volume measurements that can be used to validate or integrate satellite derived estimates since 2001 a number of airborne remote sensing surveys namely digital photogrammetry dp and airborne laser scanning als have been carried out on stromboli s volcano to obtain high resolution digital elevation models dem and orthophotos with sub meter spatial resolution and a time schedule suitable for monitoring the morphological evolution of the surface during the quiescent phases during the last two effusive eruptions 2002 2003 and 2007 the surface modifications created on the sciara del fuoco slope and on the crater area as a consequence of effusive activity were quantified and monitored using the same methodologies this work which is based on the results obtained from the multi temporal quantitative analysis of the data collected from 2001 to 2007 mainly focuses on the 2007 eruption but also accounts for analogies and differences regarding the 2002 2003 event the 2007 eruption on the sciara del fuoco slope from 27 february until 2 april produced a compound lava field including a lava delta on the shoreline discharging most of the lava into the sea the comparison of the 2007 dems with a pre eruption surface 2006 lidar survey allowed for the evaluation of the total lava volume that accumulated on the subaerial slope while two syn eruption dems were used to calculate the average effusion rates during the eruption since the evolution of a lava field produced during an eruption can be seen as a proxy for the magma intrusion mechanism hypotheses are formulated on the connection between the lava discharge and the instabilities suffered by the slope

tectonics of strike slip restraining and releasing bends restraining and releasing bends are common but enigmatic features of strike slip fault systems occurring in all crustal environments and at regional to microscopic scales of observation regional scale restraining bends are sites of mountain building transpressional deformation and basement exhumation whereas releasing bends are sites of topographic subsidence transtensional deformation basin sedimentation and possible volcanism and economic mineralization because restraining and releasing bends often occur as singular self contained domains of complex deformation they are appealing natural laboratories for earth scientists to study fault processes earthquake seismology active faulting and sedimentation fault and fluid flow relationships links between tectonics and topography tectonic and erosional controls on exhumation and tectonic geomorphology this volume addresses the tectonic complexity and diversity of strike slip restraining and releasing bends with 18 contributions divided into four thematic sections 1 a topical review of fault bends and their global distribution 2 bends sedimentary basins and earthquake hazards 3 restraining bends transpressional deformation and basement controls on development 4 releasing bends transtensional deformation and fluid flow

particle obstruction and crushing of dredged calcareous soil in the nansha islands south china sea abstract the bearing capacity of the dredged calcareous soil in the nansha islands south china sea typically exceeds that of terrigenous dredger fill furthermore the shear strength of calcareous soil exceeds that of siliceous sand under identical conditions it is mainly caused by the interparticle obstruction between calcareous soil particles to explore the obstruction mechanism of calcareous soil particles a series of triaxial tests were performed on calcareous soils under both consolidated undrained cu and consolidated drained cd conditions respectively particle shape characteristics and particle crushing were also investigated to study the formation mechanism of obstruction force test results indicate that irregular particle shape is the prerequisite for the emergence of particle obstruction in calcareous soils a simple obstruction dilatation model was developed to describe the relationship among particle obstruction dilation and particle crushing the obstruction force varies greatly during the shearing process which is mainly influenced by particle size and stress level under low confining pressure particle obstruction results in dilatation and increases internal friction angle in contrast obstruction causes particle breakage increases the apparent cohesion and ultimately decreases the effective internal friction angle under high confining pressures the particle obstruction of calcareous soil noticeably improves shear strength therefore the effect of particle obstruction on strength should be considered in coral reef engineering design work

evolution and progressive geomorphic manifestation of surface faulting a comparison of the wairau and awatere faults south island new zealand comment it is well known that continuum deformation of media with strain weakening rheology causes deformation zones to progressively decrease in width and structural complexity as shear strain is localized ben zion and sammis 2003 strain localization occurs on faults at seismogenic depth e g chester and chester 1998 boulton et al 2012 and at the surface as evidenced from detailed mapping of surface ruptures and analogue experiments in granular media tchalenko 1970 in geology zinke et al 2015 hypothesize that large differences in accumulated strike slip displacement on the wairau 460 km and awatere 20 km faults in new zealand have resulted in narrower and less complex off fault deformation zones ofd along the wairau fault despite similar slip rates lithologies and tectonic settings their hypothesis is not supported by the data they present because 1 the compared sites are structurally and topographically dissimilar and these differences may independently account for the observed rupture patterns 2 large along strike variations in the width and complexity of surface rupture zones occur along other nearby analogous faults with uniform structural maturity 3 wide and structurally complex ofd zones are common features along faults with more accumulated slip and greater structural maturity and 4 strain localization in granular media with simple boundary conditions occurs at low shear strain implying that a factor other than structural maturity may be responsible for variations in ofd width and complexity the saxton river site sr is located at a restraining bend along the awatere fault where the fault strike averaged over a distance of 15 km along the surface trace in both directions changes 12 from 64 1 ne of sr to 76 5 0 5 sw of sr the trace of the wairau fault either side of the branch river br site is comparably straight ne 67 0 5 sw 61 0 5 with the possibility of a slight 6 releasing divergence in fault strike on the nearby hope fault khajavi et al 2014 showed increases in ofd width and complexity correspond with deviations in fault strike of 10 20 restraining bends on strike slip faults are commonly associated with an increase in the width and complexity of surface ruptures e g duffy et al 2014 the sr and br sites are also topographically distinct topographic relief on the awatere fault trace exceeds 250 m within 6 km of the sr site whereas the wairau fault trace is largely confined to the wairau river valley with 400 m where it is manifested as a structurally complex mosaic of faults and folds along strike lengths of 400 km of lateral displacement sutherland 1999 and is one of earth s most structurally mature active faults are kinematically partitioned and notoriously complex with surface rupture zones commonly exceeding 300 m barth et al 2012 clearly structural maturity is not a primary control of ofd complexity and width variations along these faults strain localization onto structurally simple continuous strike slip faults at the surface occurs at low finite shear strains in quasihomogeneous granular materials with simple boundary conditions e g steep underlying fault low topographic relief shear localization occurred after lateral surface displacements of 3m in the dasht e bayaz earthquake tchalenko and ambraseys 1970 and 2 3 m in the darfield earthquake van dissen et al 2013 perhaps other controls on surface rupture morphology including near surface strain localization independent of fault maturity and variations in material properties of faulted media depth to basement near fault topography and fault strike need to be more carefully considered in future analyses

the effects of weathering on the physical and mechanical properties of igneous and metamorphic saprolites abstract the present paper presents three extensive datasets of laboratory testing on weathered geomaterials which are emblematic of soil types widely found worldwide the overall dataset includes soils originating from igneous and metamorphic rocks either coarse or fine grained and having either felsic or mafic minerals in particular the data are interpreted to highlight the effects that weathering has on the physical and mechanical properties of these natural geomaterials comparing them with published data with the aim to provide a general framework of interpretation that takes into account this geological process and links soil mechanics to engineering geology generally weathering induces a reduction in the grain size both due to physical actions e g opening of grain contacts and to the chemical decomposition of minerals resulting in the formation of clay minerals as weathering proceeds and the soil becomes finer the in situ specific volume and the location of the normal compression and critical state lines move upwards in the volumetric plane on the other hand the clay minerals cause its angle of shearing resistance to reduce when analysing the behaviour of the intact soil in all cases positive effects of structure albeit small compared to some sedimentary soils were observed and these reduced as a consequence of weathering

revealing surface deformation of the 1999 chi chi earthquake using high density cadastral control points in the taichung area central taiwan the 1999 chi chi earthquake m w 7 6 ruptured a major thrust fault along the western foothills of the central mountain range of taiwan here we use cadastral control points to detect horizontal displacement in taichung central taiwan the cadastral control points were used to identify the coordinates of buildings and acreage the coordinates of each point are measured by total station and connected to global positioning system gps control points the density of these control points is nearly 36 points km2 and the accuracy of each point is within less than 2 3 cm the government of taiwan measured cadastral control points before and after the chi chi earthquake in the taichung area northern end of the chelungpu fault 1269 control points were measured over a 35 km2 area with most control points being located on the hanging wall of the chelungpu fault on the footwall the displacement is about 1 1 1 2 m toward 123 to 128 which is consistent with gps data at the hanging wall the displacement direction concentrates at 326 to 330 in the eastern section the displacement is from 7 5 to 8 m which is consistent with gps and strong motion data but in the western part displacement changes from 8 m to 4 6 m and then increases again to 8 m along the 326 trending we conclude that the changes in displacements were controlled by the geometry of the fault plane online material horizontal displacement of cadastral control points

evolution and progressive geomorphic manifestation of surface faulting a comparison of the wairau and awatere faults south island new zealand comment zinke et al 2015 documented a flight of saxton river terraces deformed by the awatere fault south island new zealand they concluded that the manifestation of off fault deformation ofd is a cumulative effect and therefore may not be immediately apparent on younger terraces with implications for slip rate determinations i argue that they did not adequately consider the detailed structural setting of elements of ofd within the saxton river releasing bend on the awatere fault the surface deformation at saxton river is probably controlled by the coincidence of terraces with structural zones within the bend and i contest the authors conclusion that off plane deformation is simply hidden in younger terraces the influence of structural complexity on the width and geometry of ofd is well established e g milliner et al 2015 zinke et al s figure dr2 in gsa data repository 2015341 shows that ofd along the awetere fault occurs at bends or steps in the fault plane including at saxton river where the fault bends right relative to the main trace by 5 10 50 m east of the t2 t3 riser this gives rise to a graben t1 tread and two pressure ridges t2 tread and bedrock spur that define and bound an overall 150 m wide releasing bend mason et al 2006 figs 1a and 1b the paired pressure ridge and graben geometry is predicted when the wall rocks on either side of a strike slip fault approach and interact with a fault bend during an earthquake sibson 1989 and has been reported on the hope cowan 1990 and greendale duffy et al 2013 faults in new zealand and the san andreas fault in california ben zion et al 2012 among others

anisotropy of small strain stiffness in ticino sand comprehensive tests performed in a large calibration chamber and consisting of the propagation of seismic body waves in dry ticino silica sand are presented by virtue of the fact that both shear and constrained compression waves have been propagated in vertical horizontal and oblique directions five independent constants of the cross anisotropic elasticity model of the test have been established the tests have also made it possible to evaluate the influence of the structural inherent and stress induced anisotropy on the velocity of the propagated seismic body waves the influence of the principal effective stresses on the velocity of these waves is also described de nombreux essais realises dans une grande chambre d etalonnage et consistant en la propagation d ondes sismiques dans des sables siliceux et sec de ticino sont presentes les ondes de cisaillement et de compression ayant w emises dans des directions verticales horizontales et obliques les 5 constantes independantes du modele eastique

sea level comparison between topex poseidon altimetric data and a global ocean general circulation model from an assimilation perspective the topex poseidon altimetric sea level observations during 1993 are used to validate a simulation made by the laboratoire d oceanographie dynamique et de climatologie ocean general circulation model ogcm at global scales the forcing fields are provided by the european centre for medium range weather forecasts reanalysis project the ogcm is a coarse horizontal resolution model 2 longitude by 1 5 latitude with 31 levels in the vertical mainly used for climate studies horizontal mixing is done along isopycnal surfaces whereas the parameterization of vertical mixing is based on a local estimate of the turbulent kinetic energy the comparison is quantitative in the sense that topex poseidon observations are interpolated onto the model grid by an objective interpolation in view of the assimilation case the model simulation is compared to the observations at large spatial scales of 500 km or more the basic features of the variability are simulated well by the model in particular with respect to the annual cycle major discrepancies are found in the vicinity of western boundary currents and in the southern ocean due in part to the inadequate horizontal resolution in anticipation of a future assimilation of the observed sea level a decomposition of the model sea level into baroclinic barotropic components diagnosed with some dynamical variables of the model is then examined it is shown that the baroclinic component explains the large seasonal variations confined in the upper layers whereas the barotropic component is associated with intraseasonal variability the results of the present study confirm that the model sea level is consistent with the observed large scale variability providing a basis for future assimilation of the data into the ogcm to improve the representation of the ocean state

the mechanics of cemented carbonate sands the behaviour of artificially cemented carbonate sand was investigated in triaxial tests at confining pressures of up to 9 mpa the results show that an important effect of cementing is a reduction in specific volume resulting from the increase in fines content this influences both the stress strain behaviour and the peak strength at strains beyond those required to fracture the cement bonding comparisons between the behaviour of cemented and uncemented soils should therefore be carried out on samples with the same gradings for cemented samples it is possible to identify a yield curve outside the state boundary surface of the uncemented soil a framework for the behaviour has been defined which depends on the relative magnitudes of the confining pressure and cement bond strength the behaviour of a natural cal carenite agreed well with this framework which is also likely to be applicable to other cemented soils le comportement d un sable carbonate artificiellement cimente a ete etudie a l aide d essa

an elastic rebound model for normal fault earthquakes a viscoelastic finite element method is used to formulate an elastic rebound model for normal fault earthquake cycles model generated displacements correlate well with geodetic survey data collected before and after the 1954 m 7 1 fairview peak nevada and the 1959 m 7 1 hebgen lake montana earthquakes model coseismic deformation results in an uplift of the footwall block and a depression of the hanging wall block as has been reported by savage and hastie 1966 the interseismic phase of the deformation is characterized by a regional doming of the crust in the vicinity of the modeled normal faults doming observed before and after and adjacent to the faults which ruptured during the hebgen lake earthquake indicate that areas which are experiencing doming may be the future sites of normal fault earthquakes two areas which are presently experiencing crustal doming and are in the vicinity of a normal fault are the socorro new mexico and diablo plateau texas brown et al 1978 regions the interseismic doming will not occur if the modeled fault ruptures through the entire lithosphere if a single normal fault is active then model generated coseismic and interseismic deformations result in sum to a tilt block topography if two normal faults are active one master fault and a minor fault which dips toward the master fault then the resultant deformation is a horst and graben type of topography the rate at which the doming proceeds is primarily a function of the seismic stress drop and the effective viscosity of the asthenosphere doming rates following the hebgen lake earthquake indicate an asthenospheric viscosity of about 2 1021 p model recurrence intervals for the fairview peak and hebgen lake earthquakes are on the order of 103 yr

evidence from coseismic slip gradients for dynamic control on rupture propagation and arrest through stepovers received 30 july 2008 revised 14 november 2008 accepted 18 december 2008 published 27 february 2009 1 analysis of historic slip distributions from large magnitude continental strike slip earthquake ruptures reveals a pronounced correlation between the distance over which slip decreases as a rupture approaches a structural step in the fault and the ability of the rupture to propagate through the step our analysis of coseismic slip gradients near these stepovers indicates that in earthquakes in which slip decreases gradually toward a step rupture will not continue on the next segment conversely in earthquakes in which slip decreases abruptly rupture commonly renucleates on the next segment the fact that ruptures that stopped had low slip gradients near stepovers relative to those that continued indicates that rupture dynamics control the propagation of rupture through stepovers these results corroborate dynamic rupture models that show that ruptures in which slip decreases abruptly at a step generate strong seismic waves that serve to renucleate rupture on the opposite side of the structural step there are several potential causes for gradual decrease of displacement as rupture approaches a stepover including transference of deformation onto subsidiary structures rheological contrasts that could dictate favored rupture propagation directions the existence of stress shadows from previous earthquakes within the system or other material or frictional heterogeneities all of these are potentially observable and if mapped systematically could provide the basis for a strong constraint on the likely end points of future earthquakes inasmuch as earthquake magnitude is strongly dependent on the size of the rupture such predictions would be of great utility as a basic component of scenario based earthquake rupture forecasts

small strain stiffness of carbonate kenya sand abstract in this paper results of a series of tests performed in a large calibration chamber cc consisting in the propagation of seismic shear and compression waves in dry carbonate oolitic sand from kenya are presented and analysed the tests were aimed at assessing how the state parameters affect the small strain shear and constrained moduli the tested sand was characterised by the determination of the index properties its mineralogy and grain crushing the latter investigated by oedometer tests the calibration chamber houses a cylindrical specimen 1 2 m diameter and 1 5 m high within the specimens reconstituted by dry pluviation at relative densities of 30 and 85 were embedded arrays of three miniaturised geophones used alternatively as source and receiver of seismic body waves shear and compression waves were propagated along the vertical horizontal and inclined planes by assuming a cross anisotropic medium with a vertical axis of symmetry the seismic tests allowed the assessment of the elastic parameters the effects of the fabric of the stress induced anisotropy as well as the stress history on the velocity of propagated seismic body waves are quantified and described in details semi empirical correlations are calibrated they can be used in engineering practice to analyse body wave velocity profiles measured in situ and to evaluate the state parameters and anisotropy properties of carbonate sand deposits

surface rupture and slip distribution of the 12 november 1999 duzce earthquake m 7 1 north anatolian fault bolu turkey the 12 november 1999 earthquake m 7 1 occurred on the duzce fault a splay of the north anatolian fault in the bolu basin approximately three months after the 17 august 1999 m 7 4 earthquake the surface rupture was 40 km long and the maximum right lateral offset was 500 5 cm averaging 300 cm the 9 km of the westernmost part of the rupture along the southern margin of the eften lake had a 350 cm maximum vertical displacement normal faulting some of which was already ruptured during the 17 august 1999 event with few tens of centimeters the surface rupture has a generally simple narrow deformation zone of 0 5 5 m however in some places it widens to 50 m transtensional and transpressional structures were observed within releasing and restraining step over areas respectively the larger dextral offsets on some streams indicate previous events the dextral slip measurements along the rupture reflect a symmetric distribution the eastern connection of this rupture zone with the main trace of north anatolian fault remains unclear because the bakacak and elmalik fault which are connecting faults had no surface rupture manuscript received 14 november 2000

late quaternary slip rates and slip partitioning on the alpine fault new zealand abstract published geological data on late quaternary offsets on the alpine fault new zealand have been assembled into a common format and analysed with respect to uncertainties uncertainties arise mainly from measurement of offset features relating apparent offsets to actual fault slip and dating the offset features despite the considerable uncertainties the data form a coherent set consistent with a relatively constant rate of strike slip of 27 5 mm year between milford sound and hokitika this rate represents 70 75 of the fault parallel interplate motion north of the confluence with the hope fault the rate drops substantially dip slip rates on the other hand show considerable variation along strike rising to a maximum of more than 10 mm year in the central section and decreasing to zero at the southern end partitioning of c 25 of the interplate slip on to structures east of the alpine fault occurs in the central section consistent with predictions from critical wedge models the partitioning of all the fault normal component of displacement on to other structures in the south may be related in part to a doubling in width of the deforming wedge to the east most probably however the fault normal displacement is mainly accommodated by underthrusting of the australian plate offshore due to a change in the nature of the crust from continental to oceanic

interactions between the landers and hector mine california earthquakes from space geodesy boundary element modeling and time dependent friction the m w 7 1 hector mine earthquake happened 7 years after the 1992 m w 7 3 landers earthquake within a system of right lateral strike slip faults comprising the eastern california shear zone because estimates of recurrence intervals of m 7 earthquakes on these faults range anywhere from 1500 to 50 000 years the close temporal spacing of these two earthquakes suggests that there is some interaction between the two current models of simple coulomb static stress interactions between the earthquake ruptures do not predict an obvious cause and effect relationship the interaction between the computed normal and right lateral shear stress reductions induced by the landers earthquake at the hector mine hypocenter is unclear we use a combination of space geodesy boundary element modeling and computer modeling of time dependent fault friction to investigate the interaction between the two earthquakes we compare stress changes on the hector mine rupture plane induced by the landers earthquake with the detailed slip distribution inferred using a combination of gps and insar data the slip distributions of both earthquakes are also used to infer the magnitude of the shear stress drop on each earthquake rupture and the orientation of the remote background stress consistent with these two recent events for each earthquake the azimuth of the remote maximum compressive stress was approximately 17 6 and the magnitude of the shear stress drop was 8 1 mpa on the landers rupture and 10 2 mpa on the hector mine rupture using a simple spring and slider model as a proxy for the rate and state frictional response of the hector mine faults to landers earthquake imposed stress steps we find that while a decrease in normal stress at the hector mine hypocenter would by itself have caused the hector mine earthquake to nucleate immediately the simultaneous decrease in shear stress may have caused a delay in the peak shear loading consideration of an acceptable range of rate and state friction parameters secular strain rates and crustal stiffnesses leads us to conclude that this delay could have been 0 to 40 years

high resolution topography along surface rupture of the 16 october 1999 hector mine california earthquake mw 7 1 from airborne laser swath mapping in order to document surface rupture associated with the hector mine earthquake in particular the area of maximum slip and the deformed surface of lavic lake playa we acquired high resolution data using relatively new topographic mapping methods we performed a raster laser scan of the main surface breaks along the entire rupture zone as well as along an unruptured portion of the bullion fault the image of the ground surface produced by this method is highly detailed comparable to that obtained when geologists make particularly detailed site maps for geomorphic or paleoseismic studies in this case however for the first time after a surface rupturing earthquake the detailed mapping is along the entire fault zone rather than being confined to selected sites these data are geodetically referenced using the global positioning system thus enabling more accurate mapping of the rupture traces in addition digital photographs taken along the same flight lines can be overlaid onto the precise topographic data improving terrain visualization we demonstrate the potential of these techniques for measuring fault slip vectors

paleoseismology of the 2010 mw 7 1 darfield canterbury earthquake source greendale fault new zealand abstract the previously unknown greendale fault ruptured in the september 2010 moment magnitude mw 7 1 darfield earthquake surface rupture fracture patterns and displacements along the fault were measured with high precision using real time kinematic rtk gps tape and compass airborne light detection and ranging lidar and aerial photos no geomorphic evidence of a penultimate surface rupture was revealed from pre 2010 imagery the fault zone is up to 300 m wide and comprises both distributed folding and discrete faulting deformation dominated by right lateral displacement surface fracturing accommodates 30 of the total right lateral displacement in the central fault zone the remainder is accommodated by distributed deformation ground penetrating radar and trenching investigations conducted across the central greendale fault reveal that most surface fractures are undetectable at depths exceeding 1 m however large discrete riedel shears continue to depths exceeding 3 m and displace interbedded gravels and sand filled paleochannels at one trench site a riedel shear displaces surface agricultural markers e g fences and plow lines and a subsurface 0 6 m deep paleo channel by 60 cm right laterally and 10 cm vertically indicating the paleochannel has been displaced only in the darfield earthquake optically stimulated luminescence osl dating of the displaced paleochannel yields an age of 21 6 1 5 ka two additional paleochannels at 2 5 m depth with osl ages of 28 4 2 4 ka and 33 2 ka have been displaced 120 cm right laterally and 20 cm vertically the doubling of displacement at depth is interpreted to indicate that in the central section of the greendale fault the penultimate surface rupturing event occurred between ca 20 and 30 ka the greendale fault remained undetected prior to the darfield earthquake because the penultimate fault scarp was eroded and buried during late pleistocene alluvial activity similar active faults with low slip rates i e lower than sedimentation erosion rates are likely to be concealed in alluvial settings globally

locating distributed faulting contributions from insar imaging to probabilistic fault displacement hazard analysis pfdha abstract prediction of location and amount of slip for distributed faulting associated to strong earthquakes is a recently explored issue with major implications in terms of hazard assessment currently the best practice involves the applications of probabilistic fault displacement hazard analysis pfdha whose results fit sufficiently well real data in the near range of the primary fault but show considerable inaccuracies in the far range we believe that this inaccuracy descends from the biased earthquake databases used for regression analysis whose data relative to old earthquakes were largely collected only by field surveys focused close to the primary fault i e near range remotely sensed data i e interferometric radar imaging insar offer the opportunity to precisely measure the surface deformation induced by strong earthquakes and thus to explore its possible relation with distributed faulting we analyze the l aquila earthquake case study 29th april 2009 mw 6 3 and explore the correlation between location and slip on distributed faulting and insar derived deformation field we find a significant correlation between occurrence of distributed faulting and profile curvature of the dislocation field in spite of the distance from the primary fault moreover distributed faults tend to occur within the area deformed by the earthquake as imaged by insar data and whose extent is directly proportional to the earthquake magnitude mw according to a dataset of 30 recent earthquakes we then propose that these observations have to be incorporated into the present pfdha practice as limit boundaries to possible scenarios of probabilistic analysis and that an integrated use of field based and remotely data collection have to be implemented following strong earthquakes

how well do surface slip measurements track slip at depth in large strike slip earthquakes the importance of fault structural maturity in controlling on fault slip versus off fault surface deformation abstract comparisons of observed surface displacements with geodetically inferred slip at depth in six large m w 7 1 strike slip earthquakes reveal a correlation between the structural maturity of the fault and the ratio of deep slip to surface slip that occurs on localized zones of surface rupture specifically structurally immature faults 25 km of total displacement manifest only 50 60 of total slip on narrow fault surface traces versus 85 95 for structurally mature faults 85 km total slip the same pattern holds when structurally simple parts of a surface rupture are analyzed separately from parts that exhibit obvious structural complexity e g discontinuous or multiple traces or significant dip slip these results imply that geologic measurements of surface slip along structurally immature faults are likely to significantly underestimate the true slip at depth in large earthquakes this observation has implications for a number of important problems including determination of fault slip rates which are based on surface offsets earthquake probability assessments which are based on geologic fault slip rates comparisons of geologic and geodetic rate data in the search for strain transients the structural evolution of fault zones estimation of paleo earthquake magnitudes based on geomorphic offsets analyses of the relative importance of faulting vs distributed deformation in accommodating relative plate motions in continental crust the design and construction of infrastructure built near active faults and possibly for the prediction of strong ground motions which may at least partially depend on the degree of slip localization to the surface

revealing coseismic displacements and the deformation zones of the 1999 chi chi earthquake in the tsaotung area central taiwan using digital cadastral data 1 the 1999 chi chi taiwan earthquake mw 7 6 was the largest earthquake to strike taiwan in the twentieth century this earthquake is associated with a 100 km long surface rupture in order to reveal the details of displacement near the surface rupture we use a digital cadastral system to calculate coseismic displacement around the tsaotung area central taiwan the digital cadastral system was originally conceived to survey land and building boundaries in the tsaotung area taiwan authorities have taken digital cadastral measurements before and after the chi chi earthquake the cadastral system affords high density control points that reach 1421 points km2 a system denser than that of the gps accuracy is to within 11 cm a level that is higher than spot imaging and one that allows us to study surface deformation in detail coseismic displacement is 4 3 4 6 m at distance from the surface rupture and decreases to 3 4 m near the surface rupture the azimuth of horizontal displacements is 310 315 and rotates to 280 305 near the surface rupture this produced a compression left lateral deformation zone with 10 3 compression strain near the surface rupture coseismic displacement of the footwall is 1 1 2 m in 110 which is similar to that from using gps data in the tsaotung thrust slice we observed that the azimuth of horizontal displacement rotates from a nw trend to a south trend as a result of slip partitioning and gravity slide effect

rupture process of the 1999 mw 7 1 duzce earthquake from joint analysis of spot gps insar strong motion and teleseismic data a supershear rupture with variable rupture velocity we analyze the rupture process of the 1999 m w 7 1 duzce earthquake using seismological remote sensing and geodetic data ground deformation measured from the subpixel cross correlation of satellite pour l observation de la terre spot images reveals a 55 km long fault trace and smooth surface slip distribution peaking at 3 5 4 m the westernmost segment overlaps for over 10 km with ruptures from the m w 7 4 izmit earthquake the 15 km long easternmost segment which cuts across mountainous topography had not been reported previously we determine a well constrained source model using a four segment fault geometry using constraints on surface fault slip and inverting global positioning system and interferometric synthetic aperture radar data along with strong motion records our results show that some variability of the rupture velocity and an eastward supershear velocity are required to fit the strong motion data the rise time up to 6 sec correlates with cumulative slip suggesting a sliding velocity of about 1 m sec the source model predicts teleseismic waveforms well although early by 2 sec this time shift is probably due to the weak beginning of the earthquake that is not observable at teleseismic distances strong motion records are relatively well predicted from a source model derived from the teleseismic data using the fault geometry derived from the satellite images this study demonstrates the benefit of using accurate fault geometries to determine finite fault source models

vertically propagating annual and interannual variability in an ogcm simulation of the tropical pacific ocean in 1985 94 abstract the annual and interannual variability in the subthermocline equatorial pacific is studied in a simulation of the tropical pacific for the 1985 94 decade using a primitive equation high resolution model the study focuses on temperature variability and vertical energy fluxes similar to the observations made by w s kessler and j p mccreary the annual harmonic of vertical isotherm displacements presents phase lines sloping downward from east to west with off equatorial maxima estimates of zonal and vertical phase speeds the location of the maxima of isotherm displacements and an analysis of ernergy fluxes suggest the presence of l 1 rossby waves the simulated field is somewhat more trapped toward the equator than the observations a linear simulation is carried out for the vertical standing modes with characteristics derived from the ogcm simulation in the linear simulation high order meridional mode rossby waves are more prominent than in the ogcm simulation however the l 1 ros

fault slip distribution of the 1999 mw 7 1 hector mine earthquake california estimated from postearthquake airborne lidar data the 16 october 1999 hector mine earthquake m w 7 1 was the first large earthquake for which postearthquake airborne light detection and ranging lidar data were collected to image the fault surface rupture in this work we present measurements of both vertical and horizontal slip along the entire surface rupture of this earthquake based on airborne lidar data acquired in april 2000 we examine the details of the along fault slip distribution of this earthquake based on 255 horizontal and 85 vertical displacements using a 0 5 m digital elevation model derived from the lidar imagery the slip measurements based on the lidar dataset are highest in the epicentral region and taper in both directions consistent with earlier findings by other works the maximum dextral displacement measured from lidar imagery is 6 60 1 10 m located about 700 m south of the highest field measurement 5 25 0 85 m our results also illustrate the difficulty in resolving displacements smaller than 1 m using lidar imagery alone we analyze slip variation to see if it is affected by rock type and whether variations are statistically significant this study demonstrates that a postearthquake airborne lidar survey can produce an along fault horizontal and vertical offset distribution plot of a quality comparable to a reconnaissance field survey although lidar data can provide a higher sampling density and enable rapid data analysis for documenting slip distributions we find that relative to field methods it has a limited ability to resolve slip that is distributed over several fault strands across a zone we recommend a combined approach that merges field observation with lidar analysis so that the best attributes of both quantitative topographic and geological insight are utilized in concert to make best estimates of offsets and their uncertainties

stress triggering and the canterbury earthquake sequence the canterbury earthquake sequence which includes the devastating christchurch event of 2011 february has to date led to losses of around 40 billion nz dollars the location and severity of the earthquakes was a surprise to most inhabitants as the seismic hazard model was dominated by an expected mw 8 earthquake on the alpine fault and an mw 7 5 earthquake on the porters pass fault 150 and 80 km to the west of christchurch the sequence to date has included an mw 7 1 earthquake and 3 mw 5 9 events which migrated from west to east here we investigate whether the later events are consistent with stress triggering and whether a simple stress map produced shortly after the first earthquake would have accurately indicated the regions where the subsequent activity occurred we find that 100 per cent of m 5 5 earthquakes occurred in positive stress areas computed using a slip model for the first event that was available within 10 d of its occurrence we further find that the stress changes at the starting points of major slip patches of post darfield main events are consistent with triggering although this is not always true at the hypocentral locations our results suggest that coulomb stress changes contributed to the evolution of the canterbury sequence and we note additional areas of increased stress in the christchurch region and on the porters pass fault

recurrent liquefaction in christchurch new zealand during the canterbury earthquake sequence continuous observational monitoring of a study site in eastern christchurch new zealand following the 2010 m w 7 1 darfi eld earthquake has recorded ten distinct liquefaction episodes in the mainshock aftershock sequence three nearby accelerometers allow calibration between the geological expressions of liquefaction and the intensity of earthquake induced surface ground motion at the site sand blow formation was generated by m w 5 2 7 1 earthquakes with m w 7 5 normalized peak ground accelerations pga 7 5 of 0 057 g acceleration due to gravity silt drapes between successive sand blow deposits provide markers for delineating distinct liquefaction inducing earthquakes in the geologic record however erosion quickly modifi es the surface of sand blows into alluvial and aeolian forms that complicate geologic diagnosis the two feeder dike generations identifi ed in subsurface investigations signifi cantly underrepresent the number of liquefaction inducing earthquakes due to extensive dike reactivation new constitutive equations enable pga 7 5 variations to be estimated from the thickness and areal extent of sand blows

isotropic yielding in an artificially cemented soil cured under stress the work simulates in the laboratory the formation of a cemented sedimentary deposit in which cement bonding occurs after burial and under geostatic stresses isotropic compression tests were carried out on artificially cemented specimens made with variable cement contents after consolidating the samples to the uncemented normal compression line the specimens were allowed to cure for 48 h before testing the curing confining stresses ranged from 50 to 2000 kpa and were intended to represent soil elements at different depths in the fictitious sedimentary deposit when the cementing occurred the contribution of the cement bonds to soil compression and the changes in the isotropic yield stress as a function of void ratio and cement content were analysed the results showed the importance of the void ratio during the formation of cement bonds and also of the degree of cementation for the compressive behaviour of the cemented soil and demonstrated that the variation in yield stress with void ratio and ce

deformation characteristics of two cemented calcareous soils the effect of cementation on the deformation characteristics of two cemented calcareous soils was investigated through a series of undrained triaxial tests performed under both monotonic and cyclic

speculations on the geometry of the initiation and termination processes of earthquake rupture and its relation to morphology and geological structure earthquake initiation and termination processes are commonly described in terms of barriers and asperities barriers fall into two classes geometric barriers are associated with places where the orientation of a failure surface changes and relaxation barriers where stress is low because aseismic creep processes outpace tectonic loading geometric barriers fall into conservative and nonconservative subgroups according to whether finite fault motion can proceed without the creation of new structures or whether it demands the creation of new faulting or void space the multiple faulting or fragmentation associated with some nonconservative barriers can disrupt fault planes and form asperities by means of selected examples it is shown that a description in terms of these barriers can help one to visualise the processes of earthquake rupture and its relation to the geological environment

arc parallel extrusion of the timor sector of the banda arc continent collision structural studies of synorogenic basins in timor using field and remote sensing techniques provide new structural and geomorphic evidence for syn collisional extension in the converging plate boun

coseismic landsliding during the mw 7 1 darfield canterbury earthquake implications for paleoseismic studies of landslides abstract the head scarp of the harper hills landslide consists of ground cracks with vertical displacement and extension that opened during the 2010 darfield canterbury mw 7 1 earthquake the geomorphology of the cracks regional geology and ground penetrating radar indicate that the landslide formed by bedding controlled translation and joint controlled toppling and suggest incipient deep seated movement crack depth and displacement along the head scarp vary along the ridge maximum values are located where the head scarp is closest to the local ridge line increased seismic shaking due to topographic and geometric amplification of seismic waves is suggested as an explanation for this relationship an excavation across the head scarp revealed no evidence of prior slip events over a time period that is likely to exceed the return period 1000 2500 years of peak ground accelerations experienced at this location in the darfield earthquake we suggest that specific seismologic attributes of the darfield earthquake may have influenced the location of landsliding in this instance studies of paleo landslides must consider crack preservation potential as well as complex source site effects that may complicate estimates of acceleration return periods from the subsurface investigation of individual landslide head scarps

long equatorial waves in a high resolution ogcm simulation of the tropical pacific ocean during the 1985 94 toga period abstract a high resolution oceanic general circulation model ogcm of the three tropical oceans is used to investigate long equatorial wave activity in the pacific ocean during the 1985 94 toga period the arpege atmospheric general circulation model simulated zonal wind stress forcing and the opa ogcm simulated dynamic height are interpreted using techniques previously applied to data long equatorial waves of the first baroclinic mode kelvin and first mode rossby waves are detected propagating in the model outputs during the entire period a seasonal cycle and interannual anomalies are computed for each long equatorial wave in the east pacific basin long equatorial wave coefficients are dominated by seasonal variations while west of the date line they display strong interannual anomalies interannual long wave anomalies are then compared to wave coefficients simulated by a simple wind forced model the results presented here indicate the major role played by wind forcing on interannual timescales

high resolution mapping of near field deformation with airborne earth observation data a comparison study we present an investigation into different approaches for high resolution mapping of near field surface displacement for strike slip earthquakes airborne laser scanning als and optical imagery are two common sources of earth observation data available to geoscientists for earthquake documentation and studies optical image correlation and point cloud differencing techniques are among the most widely used methods for retrieving displacement signals in the near field we compare the performances of these techniques for estimating near field deformation using pre and postevent high resolution als and airborne imagery of the august 24 2014 mw 6 0 napa california earthquake estimates of deformation agree with field observations within a decimeter at the expected accuracy level of the data we show that the correlation of intensity images from als data can unveil the near field deformation successfully and outperforms optical image correlation in vegetated areas as well as in the absence of geodetic markers man made structures furthermore we illustrate that the point clouds generated with structure from motion perform comparably to als point clouds for retrieving the displacement signal in unvegetated areas overall we conclude that als data are generally better than imagery for estimating near field deformation regardless of the estimation methodology and that the iterative closest point algorithm was more effective at recovering the displacement signal

optimization of legacy lidar data sets for measuring near field earthquake displacements airborne lidar light detection and ranging topography acquired before and after an earthquake can provide an estimate of the coseismic surface displacement field by differencing the preevent and postevent lidar point clouds however estimated displacements can be contaminated by the presence of large systematic errors in either of the point clouds we present three dimensional displacements obtained by differencing airborne lidar point clouds collected before and after the el mayor cucapah earthquake a mw 7 2 earthquake that occurred in 2010 the original surface displacement estimates contained large periodic artifacts caused by systematic errors in the preevent lidar data reprocessing the preevent data detailed herein removed a majority of these systematic errors that were largely due to misalignment between the scanning mirror and the outgoing laser beam the methodology presented can be applied to other legacy airborne laser scanning data sets in order to improve change estimates from temporally spaced lidar acquisitions

preliminary geometry displacement and kinematics of fault ruptures in the epicentral region of the 2016 mw 7 8 kaikōura new zealand earthquake

the 2010 2011 canterbury earthquake sequence environmental effects seismic triggering thresholds and geologic legacy abstract seismic shaking and tectonic deformation during strong earthquakes can trigger widespread environmental effects the severity and extent of a given effect relates to the characteristics of the causative earthquake and the intrinsic properties of the affected media documentation of earthquake environmental effects in well instrumented historical earthquakes can enable seismologic triggering thresholds to be estimated across a spectrum of geologic topographic and hydrologic site conditions and implemented into seismic hazard assessments geotechnical engineering designs palaeoseismic interpretations and forecasts of the impacts of future earthquakes the 2010 2011 canterbury earthquake sequence ces including the moment magnitude m w 7 1 darfield earthquake and m w 6 2 6 0 5 9 and 5 8 aftershocks occurred on a suite of previously unidentified primarily blind active faults in the eastern south island of new zealand the ces is one of earth s best recorded historical earthquake sequences the location of the ces proximal to and beneath a major urban centre enabled rapid and detailed collection of vast amounts of field geospatial geotechnical hydrologic biologic and seismologic data and allowed incremental and cumulative environmental responses to seismic forcing to be documented throughout a protracted earthquake sequence the ces caused multiple instances of tectonic surface deformation 3 events surface manifestations of liquefaction 11 events lateral spreading 6 events rockfall 6 events cliff collapse 3 events subsidence 4 events and hydrological 10s of events and biological shifts 3 events the terrestrial area affected by strong shaking e g peak ground acceleration pga 0 1 0 3 g and the maximum distances between earthquake rupture and environmental response r rup both generally increased with increased earthquake m w but were also influenced by earthquake location and source characteristics however the severity of a given environmental response at any given site related predominantly to ground shaking characteristics pga peak ground velocities and site conditions water table depth soil type geomorphic and topographic setting rather than earthquake m w in most cases the most severe liquefaction rockfall cliff collapse subsidence flooding tree damage and biologic habitat changes were triggered by proximal moderate magnitude m w 6 2 earthquakes on blind faults ces environmental effects will be incompletely preserved in the geologic record and variably diagnostic of spatial and temporal earthquake clustering liquefaction feeder dikes in areas of severe and recurrent liquefaction will provide the best preserved and potentially most diagnostic ces features rockfall talus deposits and boulders will be well preserved and potentially diagnostic of the strong intensity of ces shaking but challenging to decipher in terms of single versus multiple events most other phenomena will be transient e g distal groundwater responses not uniquely diagnostic of earthquakes e g flooding or more ambiguous e g biologic changes preliminary palaeoseismic investigations in the ces region indicate recurrence of liquefaction in susceptible sediments of 100 to 300 yr recurrence of severe rockfall event s of ca 6000 to 8000 yr and recurrence of surface rupturing on the largest ces source fault of ca 20 000 to 30 000 yr these data highlight the importance of utilising multiple proxy datasets in palaeoearthquake studies the severity of environmental effects triggered during the strongest ces earthquakes was as great as or equivalent to any historic or prehistoric effects recorded in the geologic record we suggest that the shaking caused by rupture of local blind faults in the ces comprised a worst case seismic shaking scenario for parts of the christchurch urban area moderate m w blind fault earthquakes may contribute the highest proportion of seismic hazard be the most important drivers of landscape evolution and dominate the palaeoseismic record in some locations on earth including locations distal from any identified active faults a high scientific priority should be placed on improving the spatial extent and quality of off fault shaking records of strong earthquakes particularly near major urban centres

localised and distributed deformation in the lithosphere modelling the dead sea region in 3 dimensions article i nfo the earth s lithosphere behaves as a strain softening elasto plastic material in the laboratory such materials are known to deform in a brittle or a ductile manner depending on the applied geometric boundary conditions in the lithosphere however the importance of boundary conditions in controlling the deformation style has been largely ignored under general boundary conditions both laboratory and field scale observations show that only part of the deformation can localise on through going faults while the rest must remain distributed in process zones where spatially varying shear directions inhibit localisation conventional modelling methods finite difference finite or discrete elements use rheologies deduced from laboratory experiments that are not constrained as a function of the geometry of the applied boundary conditions in this paper we propose an alternative modelling method that is based on the use of an appropriate distribution of dislocation sources to create the deformation field this approach because it does not rely on integrating differential equations from more or less well constrained boundary conditions does not require making assumptions on the parameters controlling the level and distribution of stresses within the lithosphere it only supposes that strain accumulates linearly away from the dislocation singularities satisfying the compatibility equations we verify that this model explains important and hitherto unexplained features of the topography of the dead sea region following the idea that strain can only localise under specific conditions as inferred from laboratory and field scale observations we use our model of deformation to predict where deformation can localise and where it has to remain distributed we find that 65 of the deformation in the dead sea region can localise on kinematically stable through going strike slip faults while the remaining 35 has to remain distributed observations suggest that distributed deformation occurs at stress levels that can be ten times greater than that associated with motion on well localised faults thus although only representing a minor part of the total deformation distributed deformation should provide the greatest source of resistance to motion along this part of the levant plate these results can change dramatically our view of the behaviour of this and other plate boundaries if the lithosphere can be regarded as a strain softening elasto plastic material then similar behaviour should occur throughout with important implications not only for its mechanical behaviour but also for heat generation and related issues like metamorphism or magma genesis