sand boils induced by the 1993 mississippi river flood could they one day be misinterpreted as earthquake induced liquefaction in areas that are seismically active but lacking clear surficial faulting many paleoearthquake studies depend on the interpretation of ancient liquefaction features sand blows as indicators of prehistoric seismicity sand blows however can be mimicked by nonseismic sand boils formed by water seeping beneath levees during floods we examined sand boils induced by the mississippi river flood of 1993 in order to compare their characteristics with sand blows of the new madrid earthquakes of 1811 1812 we found a number of criteria that allow a distinction between the two types of deposits 1 earthquake induced liquefaction deposits are broadly distributed about an epicentral area whereas flood induced sand boils are limited to a narrow band along a river s levee 2 the conduits of most earthquake induced sand blows are planar dikes whereas the conduits of flood induced sand boils are most commonly tubular 3 depression of the preearthquake ground surface is usual for sand blows not for sand boils 4 flood induced sand boils tend to be better sorted and much finer than sand blow deposits 5 source beds for earthquake induced deposits occur at a wide range of depths whereas the source bed for sand boils is always near surface 6 materials removed from the walls surrounding the vent of a sand blow are seen inside sand blows but are rarely seen inside sand boils in general flood induced sand boils examined are interpreted to represent a less energetic genesis than earthquake induced liquefaction

sedimentary structures tentatively attributed to seismic events abstract fingerprints of earthquakes in the sedimentary record are as yet difficult to identify this is particularly true for failure phenomena dewatering slumping fault graded and turbidite structures that could have been triggered also by other kinds of energy input other promising candidates are strange biostratinomic features convex down stacking of shells current orientation in wave ripple accumulations as well as certain preservational features found in geosynclinal pelagic limestones but in every case verification of the seismic origin is still needed

a slump in the trench tracking the impact of the 2011 tohoku oki earthquake we present differential bathymetry and sediment core data from the japan trench sampled after the 2011 tohoku oki offshore japan earthquake to document that prominent bathymetric and structural changes along the trench axis relate to a large 27 7 km 2 slump in the trench transient geochemical signals in the slump deposit and analysis of diffusive re equilibration of disturbed so 4 2 profiles over time constrain the triggering of the slump to the 2011 earthquake we propose a causal link between earthquake slip to the trench and rotational slumping above a subducting horst structure we conclude that the earthquake triggered slump is a leading agent for accretion of trench sediments into the forearc and hypothesize that forward growth of the prism and seaward advance of the deformation front by more than 2 km can occur episodically during a single event large mega thrust earthquake

interpreting soft sediment deformation and mass transport deposits as seismites in the dead sea depocenter we have studied the history of earthquakes over the past 70 kyr by analyzing disturbed sedimentary layers around the margins of the dead sea however we know little about disturbances in the basin depocenter where water depth is 300 m and accessible only by drilling in this study we compare disturbances from the dead sea depocenter with the contemporaneous earthquake record 56 30 ka that was recovered on the western margin of the lake this comparison allows us to discern the characteristics of disturbance in the different subaqueous environments and identify the source and sedimentary process of mass transport deposits our observations indicate that i the long disturbance sequences in the dead sea depocenter are composed of in situ deformation slump and chaotic deposits ii earthquake triggered kelvin helmholtz instability is a plausible mechanism for the in situ deformation in the lake center iii the slump is slope area sourced iv the unit of chaotic deposits is lakeshore sourced and v earthquake triggered slope instability is a viable mechanism for the slump and chaotic deposits we further suggest that long sequences of disturbance in seismically active lake depocenters can be used to infer earthquake clusters

soft sediment deformation structures induced by cyclic stress of storm waves in tempestites miocene guadalquivir basin spain the identification of triggering agents for soft sedimentation structures is an enigmatic geological problem mainly seismic induced soft sediment structures have been recognized in ancient sediments rather than those resulting from storm waves we analyse soft sediment deformation structures in upper miocene calcarenitic tempestites of the guadalquivir basin southern spain the most common structures are load casts which vary in height and width from 10 centimetres to several metres the structures are always restricted to a small part of the stratigraphic sections in exclusive association with tempestites the analysed soft deformation structures are interpreted to be the result of liquidization processes chiefly from their inferred depositional environment and subordinately from the deformation style we have devised basic criteria to identify the trigger mechanism in these soft sediment deformation structures the liquefaction was triggered by pore pressure changes induced by cyclic and residual stress of storm waves

contribution of radar interferometry to a two step inversion of the kinematic process of the 1992 landers earthquake we study the rupture process of the 1992 landers earthquake to limit the trade off between slip amplitude and rupture time that affects solutions using only seismological data we adopt a two step approach we first constrain the slip distribution and its uncertainty by independent geodetic data to recover in the second step the temporal details of the rupture propagation the first step consists of an inversion of interferometric data and global positioning system measurements both independently and together to constrain slip distribution on a three segment fault model along both strike and dip direction we use a genetic algorithm to test the uniqueness of the solution and a least squares formulation to find the model which best fits the data we conclude from the results of these geodetic inversions that interferometric data are rich enough to access the slip distribution in the case of the landers earthquake since the surface deformations are more sensitive to shallow slip in our configuration the slip amplitude is better resolved near the surface than at depth the resulting slip distribution is in agreement with geological observations at the surface and confirms the heterogeneous nature of the landers earthquake most of the slip occurs at shallow depths on the homestead valley fault second segment with a maximum value of around 7 m another high slip zone is observed on the johnson valley fault first segment at 8 km depth in the second step we invert strong motion data with the a priori final slip amplitude and its uncertainty deduced from geodetic data to constrain the time history of the rupture process this second step emphasizes a strong variation of the temporal development of the earthquake fast rupture front velocities appear within high slip zones and the rupture slows when it encounters a resistance along the fault on average the rupture front propagates with velocities close to the s wave velocity and terminates about 20 s after initiation the large variations in both slip amplitude and rupture velocity suggest that the rupture process is better described by successively breaking asperities than by a pulse propagating with constant velocity

multiarchive paleoseismic record of late pleistocene and holocene strong earthquakes in switzerland a multiarchive approach has been applied to the investigation of the late pleistocene and holocene record of strong earthquakes in switzerland the geological archives used for this study include active faults lake deposits slope instabilities and caves in the basle area eight trenches were opened across the basle reinach fault nearby rockfall deposits were systematically investigated sediment cores were taken from two lakes and nine caves were studied in central switzerland five lakes were investigated by means of high resolution seismic lines and sediment cores furthermore three caves were studied in central switzerland altogether the investigations are based on more than 350 km of high resolution reflection seismic lines 450 m of core samples 260 m of trenches and 245 radiocarbon age determinations the measured co seismic displacements along the basle reinach fault supply independent information for the magnitude of the ad 1356 basle earthquake exclusively based on geological evidence deformation features related to three well documented strong historic earthquake shocks were identified deformation features of the ad 1774 altdorf and ad 1601 unterwalden earthquakes can be used to calibrate paleoseismic evidence in central switzerland altogether traces of 13 earthquakes could be found in the two study areas all of them with magnitudes mw 6 or greater for the first time the earthquake catalogue for switzerland can be extended back beyond historic records into the late pleistocene spanning 15 000 years d 2005 elsevier b v all rights reserved

coseismic crustal deformations of 1994 northridge california earthquake detected by interferometric jers 1 synthetic aperture radar coseismic deformations of the january 17 1994 northridge california earthquake are mapped using interferometric combination of synthetic aperture radar images acquired by the japanese earth resource satellite jers 1 on april 30 1993 and june 14 1994 we make an interferogram in a rectangular area with a size of 18 6 km n s by 29 9 km e w although coherence is not perfect in some areas fringes in flat and inhabited areas clearly show the coseismic movements to remove ambiguity of the fringes due to inaccurate orbital information we use a least squares adjustment to minimize the difference between the radar and the global positioning system gps measurements the difference between the radar and gps measurements is less than 3 5 cm the observed fringe patterns agree with a gps based theoretical fault model within 10 cm we also find a lobed pattern that suggests up to 20 cm of subsidence within a small area the results suggest that the l band 23 5 cm radar used by jers 1 is more robust to spatial and temporal decorrelation than the c band radar used by the ers 1 and radarsat satellites

geodetic inversion for the fault model of the 1994 shikotan earthquake the fault parameters of the 1994 shikotan earthquake were determined by inverting all available geodetic data using an iterative linearized least squares method a one fault inversion shows that a shallow dip fault plane model does not reproduce the minor deformation observed on shikotan island while a steep dip model can fit all the data well multifault inversion shows that a fault plane divided into two subfaults lengthwise is the best fitting model based on akaike s information criteria aic for shallow dip faulting mechanism this model yields a very high stress drop 40 mpa on the deeper subfault for a steep dip model a fault plane divided into two subfaults sideways gives the minimum aic all the computations for models consisting of two to eight subfaults show that the chi square values of the shallow dip models are about 10 higher than those of the steep dip models considering the high stress drop the larger chi square value and the requirements of a complex subfault system for the shallow dip model we reach the conclusion that the steep dip model is more suitable to explain the geodetic observations

surface displacement of the march 26 1997 kagoshima ken hokuseibu earthquake in japan from synthetic aperture radar interferometry a jers 1 differential l band synthetic aperture radar sar interferogram of the march 26 1997 kagoshima ken hokuseibu earthquake mw 6 1 in southwestern japan shows about 9 cm peak to peak coseismic surface displacement in the radar line of sight los direction a permanent gps array detected 1 to 2 cm horizontal displacements from this earthquake by inverting the sar and gps data together we estimated a fault mechanism without any seismological data a theoretical radar los displacement pattern from a single fault model of the earthquake motion matches the sar and gps observations closely the model assumes left lateral slip of 0 46 cm with rake angle of 19 on a rectangular fault plane of dimensions 11 km width by 12 km length we demonstrate that l band sar interferometry can describe several cm surface displacement in detail and construct a fault model however despite the acquisitions being during the cold season there are apparent water vapor signatures in the interferogram with equivalent path delays of up to 1 5 cm

the structure of the dead sea basin abstract the dead sea basin is located along the left lateral transform boundary between the arabian and sinai plates its structure and history are known from surface geology drilling seismic reflection and other geophysical data the basin comprises a large pull apart almost 150 km long and mostly 8 10 km wide which is flanked by a few kilometres wide zones of normal faulting the basin formed at about 15 ma or earlier close to the beginning of the transform motion and it reached about half its present length before the end of the miocene a strong negative gravity anomaly records a thick sediment basin fill 5 km under half its length reaching a maximum of 10 km the fill includes a few km of salt ca 6 4 ma which forms several diapirs at any one time large parts of the basin subsided simultaneously but the site of fastest subsidence seems to have shifted northward sedimentation rates reached at least hundreds of metres per million years or more in the miocene and 1 km myr in later periods the basin structure is dominated by longitudinal faults intrabasinal faults which delimit the pull apart and which are the extensions of the major strike slip faults north and south of the basin and normal faults which extend along the basin margins the latter faults express a small component of extension across the basin whereas the pull apart resulted from the much larger lateral motion along the basin in addition transverse faults divide the pull apart into several segments with somewhat different histories the pull apart grew by becoming longer parallel to the transform motion at shallow levels this was probably achieved by normal slip on transverse listric faults while the fill between them was little deformed the crust under the basin was stretched and thinned during basin lengthening which caused its subsidence basin formation was accompanied by uplifting of its flanks by 1 km sparse igneous activity occurred along the basin and its flanks its presence suggests a thermal anomaly in the lower lithosphere beneath the basin and adjacent parts of the transform

soft sediment deformation within seismogenic slumps of the dead sea basin abstract the late pleistocene lisan formation preserved next to the dead sea provides exceptional 3 d exposures of folds and faults generated during soft sediment slumping and deformation it is possible to generate a range of four different scenarios associated with overprinting in a single slump event the progressive evolution of slump systems may be broadly categorised into initiation translation cessation relaxation and compaction phases thrust packages typically define piggyback sequences during slump translation with back steepening of imbricate faults leading to collapse of folds back up the regional palaeoslope detailed evaluation of slumped horizons may also permit structures to be traced across apparently separate and distinct slumped units the recognition that slumps may be reworked by younger seismically triggered events suggests that in some cases the seismic recurrence interval may be shorter than previously anticipated

intrabasin paleoearthquake and quiescence correlation of the late holocene dead sea 1 a comprehensive multisite paleoseismic archive of the late holocene dead sea basin past 2500 years is established by constructing two age depth chronological models of two sedimentary sections exposed at the retreating shores of the modern dead sea two new paleoseismic study sites studied are the ein feshkha nature reserve outcrop located at the northern part of the basin and close to an active underwater transverse fault and the east ze elim gully outcrop at the southern part of the basin age depth regression models are calculated for these sections based on atmospheric radiocarbon ages of short lived organic debris calibrated with a bayesian model the uncertainties on individual model ages are smaller than 100 years the new chronological records are compared to a laminae counting study of the ein gedi core migowski et al 2004 located at the central dead sea basin the ein feshkha outcrop yielded the largest number of seismites in the studied time interval n 52 while lower numbers of seismites are recovered from the ze elim outcrop and ein gedi core n 15 and 36 respectively the seismites show no strong dependence on the limnological sedimentological conditions in the particular sampling sites they coappear in both shallow and deep water environments and in different sedimentary facies during time intervals when the chronologies are comparable it appears that the number of seismites is significantly larger in the northern part of the basin ein gedi and ein feshkha seismic quiescence intervals are apparent at all three sites from 2nd 4th century a d and at 500 150 b c at ze elim and ein gedi several synchronous seismites appear in all sections termed here the intrabasin seismites ibs among them 1927 1293 1202 1212 749 551 419 and 33 a d and 31 and mid 2nd century b c the recurrence time of the ibs from the 2nd century b c to the 14th century a d is 200 years compared with 100 years for all earthquakes on a diagram of epicentral distance versus magnitude historic earthquakes that are correlated with ibs plot in a field of high local intensity the farther and stronger ibs earthquakes require lower local intensities to be recorded this study demonstrates that a painstaking effort is still needed for unraveling the seismic history of the dead sea basin the results also indicate that such a study will likely be highly rewarding

global compilation of interferometric synthetic aperture radar earthquake source models 1 comparisons with seismic catalogs 1 while many earthquakes have now been studied using interferometric synthetic aperture radar insar data a full assessment of the quality and additional value of insar source parameters compared to seismological techniques is still lacking we compile a catalog of source models obtained using insar and estimate the corresponding centroid moment tensor cmt parameters we refer to this compilation as the icmt archive we compare source parameters from over 70 insar studies of 57 global earthquakes with those in the global cmt gcmt international seismological centre isc and engdahl hilst buland ehb seismic catalogs we find an overall good agreement between fault strike dip and rake values in the gcmt and icmt archives likewise the differences in seismic moment between these two archives are relatively small and we do not find support for previously suggested trends of insar leading to larger moments than seismic data however epicentral locations show substantial discrepancies which are larger for the gcmt median differences of 21 km than for the ehb and isc catalogs median differences of 10 km since insar data have a high spatial resolution and thus should map epicentral locations accurately this allows us to obtain a first independent estimate of epicentral location errors in the seismic catalogs earthquake depths from insar are systematically shallower than those in the ehb catalog with a median of differences of 5 km while this trend may be partly due to unmodeled crustal complexity it is also compatible with the observation that the rupture of crustal earthquakes tends to propagate upward in the seismogenic layer

seafloor fault ruptures along the north anatolia fault in the marmara sea turkey link with the adjacent basin turbidite record abstract the relation between seafloor fault ruptures and the generation of turbidity currents was investigated to better understand the structural growth of tectonic basins with direct implications for earthquake hazard assessment this study focuses on the holocene earthquake record of transtensional basins in the marmara sea turkey that are associated with the north anatolian fault system the physical and chemical composition of three 10 m long cores recovered from the central basin was studied at high resolution and turbidite homogenite units were identified turbidite homogenite units t h units are complex deposits that consist of a sharp basal contact and multiple fining upward beds of sand to coarse silt above all are capped by a 25 cm to 75 cm thick layer of medium to fine silt a chronology developed from radiocarbon and short lived radioisotopes allowed the correlation of these t h units to the historical record of earthquakes that in turkey goes back 2000 years we found that the best location to recover the most complete sedimentation record is in the deepest part of a basin or depocenter where t h units constitute 80 of the sediments a very good correlation was established between t h units in central basin and proximal inferred historic epicentres along the central marmara segment of the north anatolia fault that occurred in 1343 860 740 and 557 ad and two more distal earthquakes that occurred in 268 and 1963 or possibly1964 these sedimentation events can then be referred to as seismo turbidites the results when compared to findings from other transform basins in marmara sea reveal a very good correlation between t h units and historic ruptures most importantly there is a strong correlation between the inferred locations of historical earthquakes and the preservation of turbidite homogenite units in the basin adjacent to the inferred rupture the 740 ad earthquake correlates with t h units in izmit gulf and central basin and could represent a multi segment rupture of the naf generally t h units appear to be clustered through the holocene sections suggesting temporal earthquake clustering in the marmara sea region such clustering may account for the lack of t h units and hence large ruptures through the central basin since 1343

prehistoric earthquake history revealed by lacustrine slump deposits five strong paleoseismic events were recorded in the past 15 k y in a series of slump deposits in the subsurface of lake lucerne central switzerland revealing for the first time the paleoseismic history of one of the most seismically active areas in central europe although many slump deposits in marine and lacustrine environments were previously attributed to historic earthquakes the lack of detailed three dimensional stratigraphic correlation in combination with accurate dating hampered the use of multiple slump deposits as paleoseismic indicators this study investigated the fingerprint of the well described a d 1601 earthquake i vii viii mw 6 2 in the sediments of lake lucerne the earthquake triggered numerous synchronous slumps and megaturbidites within different subbasins of the lake producing a characteristic pattern that can be used to assign a seismic triggering mechanism to prehistoric slump events for each seismic event horizon the slump synchronicity was established by seismic stratigraphic correlation between individual slump deposits through a quasi three dimensional high resolution seismic survey grid four prehistoric events dated by accelerator mass spectrometry 14c measurements and tephrochronology on a series of long gravity cores occurred at 2420 9770 13 910 and 14 560 calendar yr ago these recurrence times are essential factors for assessing seismic hazard in the area the seismic hazard for lakeshore communities is additionally amplified by slump induced tsunami and seiche waves numerical modeling of such tsunami waves revealed wave heights to 3 m indicating tsunami risk in lacustrine environments

the 1999 hector mine earthquake southern california vector near field displacements from ers insar two components of fault slip are uniquely determined from two line of sight los radar interferograms by assuming that the fault normal component of displacement is zero we use this approach with ascending and descending interferograms from the ers satellites to estimate surface slip along the hector mine earthquake rupture the los displacement is determined by visually counting fringes to within 1 km of the outboard ruptures these los estimates and uncertainties are then transformed into strike and dip slip estimates and uncertainties the transformation is singular for a n s oriented fault and optimal for an e w oriented fault in contrast to our previous strike slip estimates which were based only on a descending interferogram we now find good agreement with the geological measurements except at the ends of the rupture the ascending interferogram reveals significant west side down dip slip 1 0 m which reduces the strike slip estimates by 1 to 2 m especially along the northern half of the rupture a spike in the strike slip displacement of 6 m is observed in central part of the rupture this large offset is confirmed by subpixel cross correlation of features in the before and after amplitude images in addition to strike slip and dip slip we identify uplift and subsidence along the fault related to the restraining and releasing bends in the fault trace respectively our main conclusion is that at least two look directions are required for accurate estimates of surface slip even along a pure strike slip fault models and results based only on a single look direction could have major errors our new estimates of strike slip and dip slip along the rupture provide a boundary condition for dislocation modeling a simple model which has uniform slip to a depth of 12 km shows good agreement with the observed ascending and descending interferograms

submarine earthquake geology along the north anatolia fault in the marmara sea turkey a model for transform basin sedimentation abstract the submerged portions of the north anatolia fault system beneath the marmara sea were studied with high resolution multibeam bathymetry subbottom profiling and sediment cores the major objectives were to learn about the seismic and tectonic history of the fault from the stratigraphic record at a scale similar to paleoseismic studies on land and to develop tools for submarine earthquake geology that can be applied to fault controlled basins in general we focused on holocene sediment in several marmara sea basins of different sizes the approach was to test whether 1 the depocenters of the larger basins contain a record of all historic ms 7 earthquakes within the marmara sea region 2 the small transform basins record earthquakes that rupture through them 3 vertical and strike slip holocene deformation can be quantified and 4 the effects of an earthquake generally includes both primary structural features due to rupture of the sea floor such as strata offset scarps and tilting as well as secondary effects due to shaking such as mass wasting and gravitational flows we found evidence of earthquakes that we correlate with historic events in 181 ad 740 ad 1063 ad 1343 ad 1509 ad 1766 ad 1894 ad and 1912 ad the geologic evidence is primarily from those basins adjacent to the rupture as inferred from historic data this suggests that coseismic deformation of the sea floor along the rupture is a critical factor in the sedimentary record we propose a qualitative sedimentation model that relates this coseismic deformation to mass wasting of the slope scour of the basin floor seiche motions and homogenite deposition frequent earthquake activity sheds sediments from the flanks contributes to the much thicker sediment on the basin floor and decreases the likelihood of sediment failures in response to normal marine gravity driven processes the surveying techniques and approaches used have therefore the potential of documenting earthquake ruptures of fault segments and to extend the earthquake record far before the known history thus improving hazard evaluations and the fundamental understanding of earthquake process

impacts of abrupt climate changes in the levant from last glacial dead sea levels abstract a new detailed lake level curve for lake lisan the last glacial dead sea reveals a high frequency of abrupt fluctuations during marine isotope stage 3 mis3 compared to the relatively high stand characterizing mis2 and the significantly lower holocene lake the lake level fluctuations reflect the hydrological conditions in the large watershed of the lake which in turn reflects the hydro climatic conditions in the central levant region the new curve shows that the fluctuations coincide on millennial timescales with temperature variations recorded in greenland four patterns of correlation are observed through the last ice age 1 maximum lake elevations were reached during mis2 the coldest interval 2 abrupt lake level drops to the lowest elevations coincided with the occurrence of heinrich h events 3 the lake returned to higher stand conditions along with warming in greenland that followed h events 4 significant lake level fluctuations coincided with virtually every greenland stadial interstadial cycle over glacial interglacial time scales northern hemisphere glacial cooling induces extreme wetness in the levant with high lake levels reaching 160 m below mean sea level mbmsl approximately 240 m above typical holocene levels of 400 mbmsl these orbital time scale shifts are driven by expansions of the european ice sheet which deflect westerly storm tracks southward to the eastern mediterranean resulting in increased sea air temperature gradients that invoke increased cyclogenesis and enhanced moisture delivery to the levant the millennial scale lake level drops associated with greenland stadials are most extreme during heinrich stadials and reflect abrupt cooling of the eastern mediterranean atmosphere and sea surface which weaken the cyclogenic rain engine and cause extreme levant droughts during the recovery from the effect of heinrich stadials the regional climate configuration resumed typical glacial conditions with enhanced levant precipitation and a rise in lake lisan levels similar cyclicity in the transfer of moisture to the levant affected lake levels during all of the non heinrich stadial interstadial cycles

radar interferometry and its application to changes in the earth s surface geophysical applications of radar interferometry to measure changes in the earth s surface have exploded in the early 1990s this new geodetic technique calculates the interference pattern caused by the difference in phase between two images acquired by a spaceborne synthetic aperture radar at two distinct times the resulting interferogram is a contour map of the change in distance between the ground and the radar instrument these maps provide an unsurpassed spatial sampling density 100 pixels km 2 a competitive precision 1 cm and a useful observation cadence 1 pass month 1 they record movements in the crust perturbations in the atmosphere dielectric modifications in the soil and relief in the topography they are also sensitive to technical effects such as relative variations in the radar s trajectory or variations in its frequency standard we describe how all these phenomena contribute to an interferogram then a practical summary explains the techniques for calculating and manipulating interferograms from various radar instruments including the four satellites currently in orbit ers 1 ers 2 jers 1 and radarsat the next chapter suggests some guidelines for interpreting an interferogram as a geophysical measurement respecting the limits of the technique assessing its uncertainty recognizing artifacts and discriminating different types of signal we then review the geophysical applications published to date most of which study deformation related to earthquakes volcanoes and glaciers using ers 1 data we also show examples of monitoring natural hazards and environmental alterations related to landslides subsidence and agriculture in addition we consider subtler geophysical signals such as postseismic relaxation tidal loading of coastal areas and interseismic strain accumulation we conclude with our perspectives on the future of radar interferometry the objective of the review is for the reader to develop the physical understanding necessary to calculate an interferogram and the geophysical intuition necessary to interpret it

seismic stratigraphy of lake van eastern turkey more than 1500 km of multi channel seismic reflection profiles combined with icdp international continental scientific drilling program drilling data provide important insights into the stratigraphic evolution of lake van eastern turkey three major basins tatvan northern and the deveboynu basins comprise the main lake basin and are separated by morphological highs ahlat ridge and northern ridge moreover ne sw faults parallel to the general tectonic lineament of the area dominate the entire basin and are in charge of creating graben and half graben structures well developed prograding deltaic sequences on top of the basement were recognized by seismic stratigraphy analysis most likely they formed during the initial flooding of lake van 600 ka the tatvan basin sediments are dominated by mass flow deposits of various origins alternating with undisturbed lacustrine sediments including distinct tephra layers faulting along the tatvan basin margins may have triggered margin wide slope failures ahlat ridge started to form between ca 340 ka 290 ka since then ahlat ridge was sheltered from major mass flows due to its elevation hence slow lacustrine sedimentation has prevailed throughout lake history on ahlat ridge which was the location of the main drill site during the icdp several lake level fluctuations are evident on the eastern slope area but the deep basins were permanently covered by water a significant lake level low stand ca 600 ka bp was found at 610 m below present lake level the setting of the lake changed at about 30 ka tectonic activity appears to have waned significantly as the mass transport deposition decreased across the tatvan basin while normal undisturbed lacustrine sedimentation prevailed a different setting is found in the northern basin from ca 90 ka to present especially due to the strong influx of mostly volcaniclastic turbidites causing sedimentation rates to be about 3 5 times higher drill site 1 than at site 2 ahlat ridge

high resolution geological record of historic earthquakes in the dead sea basin a 2000 year paleoseismic record of the dead sea area was recovered from a lacustrine sedimentary section the section is being exposed at the ze elim terrace on the shores of the dead sea due to the fast retreat of the lake the section consists of laminated detrital and chemical mainly aragonite sediments that were deposited in the holocene paleo dead sea eight layers in the section show deformed sedimentary structures and are identified as seismites their chronology was determined by radiocarbon dating on organic remains the seismite ages are well correlated with the historically documented earthquakes of 64 and 31 b c and 33 363 1212 1293 1834 and 1927 a d the few historically documented earthquakes that have no correlatives in the ze elim seismite record occurred in times of sedimentary hiatuses at this site e g 749 a d based on modern analogues and the association of similar disturbed layers with syndepositional faults the ze elim terrace seismites indicate m 5 5 earthquakes the average recurrence interval is estimated as 100 300 years and represents slip events on different faults in the dead sea area the ze elim section provides a unique opportunity to correlate two independent and extensive data sets the historical and sedimentary records this study opens the way for better understanding of spatial and temporal distribution of earthquakes along the dead sea transform and elsewhere

soft sediment deformation produced by tides in a meizoseismic area turnagain arm alaska turnagain arm is a semidiurnal hypertidal estuary in southeastern alaska with a recorded tidal range of 9 m contorted bedding and flow rolls preserved in tidal sediments within the estuary have previously been interpreted as resulting from the mw 9 2 great alaskan earthquake of 1964 horizons of flow rolls between undeformed beds in sediments and rock strata have been used to infer ancient earthquakes in other areas although many types of soft sediment deformation structures can be formed by earthquakes observations of sedimentation on tidal flats in the inner parts of turnagain arm in the summers of 2003 and 2004 show that a wide range of soft sediment deformation structures similar to those inferred to have been formed by earthquakes can form in macrotidal estuaries in the absence of seismic shock during sedimentation rate measurements in 2004 soft sediment deformation structures were recorded that formed during one day s tide either in response to overpressurization of tidal flats during rapid tidal drawdown or by shear stress exerted on the bed by the passage of a 1 8 m tidal bore structures consisted of flow rolls dish structures flames and small dewatering pipes in a bed 17 cm thick in the future if the flow rolls in turnagain arm were found in isolated outcrops across an area 11 km in length in an estuary known to have been influenced by large magnitude earthquakes would they be interpreted as seismites these examples show that caution is needed when using horizons of flow rolls to infer paleoseismicity in estuarine deposits because many of the mechanisms tidal flux tidal bores slumping flooding that can cause deformation in rapidly deposited unconsolidated silts and sands are orders of magnitude more common than great earthquakes

lithology of the long sediment record recovered by the icdp dead sea deep drilling project dsddp abstract the sedimentary sections that were deposited from the holocene dead sea and its pleistocene precursors are excellent archives of the climatic environmental and seismic history of the levant region yet most of the previous work has been carried out on sequences of lacustrine sediments exposed at the margins of the present day dead sea which were deposited only when the lake surface level rose above these terraces e g during the last glacial period and typically are discontinuous due to major lake level variations in the past continuous sedimentation can only be expected in the deepest part of the basin and therefore a deep drilling has been accomplished in the northern basin of the dead sea during winter of 2010 2011 within the dead sea deep drilling project dsddp in the framework of the icdp program approximately 720 m of sediment cores have been retrieved from two deep and several short boreholes the longest profile 5017 1 revealed at a water depth of 300 m reaches 455 m below the lake floor blf i e to 1175 m below global mean sea level and comprises approximately the last 220 240 ka the record covers the upper part of the amora penultimate glacial the last interglacial samra the last glacial lisan and the holocene ze elim formations and therewith two entire glacial interglacial cycles thereby for the first time consecutive sediments deposited during the mis 6 5 5 4 and 2 1 transitions were recovered from the dead sea basin which are not represented in sediments outcropping on the present day lake shores in this paper we present essential lithological data including continuous magnetic susceptibility and geochemical scanning data and the basic stratigraphy including first chronological data of the long profile 5017 1 from the deep basin the results presented here a focus on the correlation of the deep basin deposits with main on shore stratigraphic units thus providing a unique comprehensive stratigraphic framework for regional paleoenvironmental reconstruction and b highlight the outstanding potential of the dead sea deep sedimentary archive to record hydrological changes during interglacial glacial and transitional intervals

submarine and coastal sediment failure triggered by the 1995 ms 6 1 r aegion earthquake gulf of corinth greece on june 15th 1995 a locally destructive earthquake of magnitude ms 6 1 on the richter scale occurred offshore 7 5 km nne of the town of aegion in the western gulf of corinth greece an offshore survey using 3 5 khz subbottom profiling system and a remote operated vehicle rov has shown that the earthquake caused small sized subaerial to submarine sediment failure in at least four sites in three fan delta deposits the rododafni the eliki and the tolofonas the fan deltas were located within a radius of about 9 km from the epicentre the areal size of the four sediment failure sites ranged from 2 104 m2 to 6 105 m2 whilst the volume of the failed masses ranged from 4 103 to 3 106 m3 the sediment deformation types identified at the failure sites consist of ground cracking rotational slides elongated slides sediment gravity flows and extrusion of mixtures of water and sand sand boils the sediment failure in the four sites affected the upper 5 6 m of well layered holocene topset and foreset fan delta deposits the failure occurred on slopes ranging from 0 2 to 23 and the slip planes were all bedding planes which have a gradient from 0 2 to 21 the dominant instability mechanism that caused the sediment failure in the rododafni and eliki fan deltas is considered to be liquefaction of a shallow sub surface horizon the liquefaction was caused by elevated pore pressure enhanced perhaps by the presence of gas resulting from the cyclic loading induced by the earthquake the liquefied layer is assumed to have temporarily provided a failure surface for sliding to take place on and caused movement of sand that was ejected onto the surface in the tolofonas fan delta the causative mechanism in the case of the multi block rotational slide is considered to be deformation of the underlying sediments caused by remoulding and or liquefaction while in the case of the elongated slide it is considered to be the result of a combination of shear stress increase and or strength degradation of the unconsolidated sediment both of these conditions could have been generated during the cyclic loading resulting from the aegion earthquake the study of historical documents reveals that sediment failure like those described above have also occurred at least four times during the past 2500 years in the same locations therefore it is suggested that they could be repeated in the future by any earthquake event with a magnitude greater than 6 r depending upon the proximity of the site to the earthquake epicentre

soft sediment deformation by kelvin helmholtz instability a case from dead sea earthquakes abstract the standard explanation for soft sediment deformation is associated with overturn of inverted density gradients however in many cases observations do not support this interpretation here we suggest an alternative in which stably stratified layers undergo a shear instability during relative sliding via the kelvin helmholtz instability khi mechanism triggered by earthquake shaking dead sea sediments have long stood out as a classical and photogenic example for recumbent folding of soft sediment these billow like folds are strikingly similar to khi structures and have been convincingly tied to earthquakes our analysis suggests a threshold for ground acceleration increasing with the thickness of the folded layers the maximum thickness of folded layers order of decimeters corresponds to ground accelerations of up to 1 g such an acceleration occurs during large earthquakes recurring in the dead sea

prehistoric earthquake deformations near masada dead sea graben earthquake inducedfluidizations and suspensions of lake sediments associated with syndepositionalfaults formapaleoseismicrecordinthedeadseagraben theassociation offluidized beds with surface faulting supports the recognition of mixed layers as reliable earthquake indicators and provides a tool for the study of very long term 70 kar seismicity along the dead sea transform the faults compose a fault zone that offsets laminated sediments of the late pleistocene lake lisan they exhibit displacements of as much as 2 m layers of massive mixtures of laminated fragments are interpreted as disturbed beds each formed by an earthquake the undisturbed laminated layers between these mixed layers represent the interseismic interval a typical vertical slip of about 0 5 m per event is separated by several hundred years of quiescence the fault zone lies within the dead sea graben 2 km east of masada where archaeology and historical accounts indicate repeated strong earthquake damage the distribution of strikes in the fault zone resembles that of the faults exposed in and around the graben including the seismogenic ones the excellent exposures over hundreds of metres allow an unprecedented temporal and spatial resolution of slip events on faults

coseismic deformation associated with the november 1995 mw 7 1 nuweiba earthquake gulf of elat aqaba detected by synthetic aperture radar interferometry the november 22 1995 mw 7 1 nuweiba earthquake occurred along one of the left stepping segments of the dead sea transform in the gulf of elat aqaba although it was the largest earthquake along this fault in the last few centuries little is yet known about the geometry of the rupture the slip distribution along it and the nature of postseismic deformation following the main shock in this study we examine the surface deformation pattern during the coseismic phase of the earthquake in an attempt to better elucidate the earthquake rupture process as the entire rupture zone was beneath the waters of the gulf and there is very little global positioning system gps data available in the region for the period spanning the earthquake interferometric synthetic aperture radar insar provides the only source of information of surface deformation associated with this earthquake we chose four synthetic aperture radar sar scenes of about 90 90 km each spanning the rupture area imaged by the ers 1 and ers 2 satellites the coseismic interferograms show contours of equal satellite to ground range changes that correspond to surface displacements due to the earthquake rupture interferograms that span the earthquake by 1 week show similar fringe patterns as those that span the earthquake by 6 months suggesting that postseismic deformation is minor or confined to the first week after the earthquake a high displacement gradient is seen on the western side of the gulf 20 40 km south of elat and aqaba where the total satellite to ground range changes are at least 15 cm the displacement gradient is relatively uniform on the eastern side of the gulf and the range changes are less than 10 cm to interpret these results we compare them to synthetic interferograms generated by elastic dislocation models with a variety of fault parameters although selecting the best fit fault parameters is nonunique we are able to generate a group of simplified model interferograms that provide a reasonable fit to the coseismic interferogram and serve to constrain the location of the fault the present analysis shows that if the rupture reached the gulf bottom surface the mean sinistral slip along the fault is constrained to about 1 4 m if surface rupture did not occur the average sinistral slip is constrained to the range of 1 4 3 m for a fault patch buried 0 4 km below the gulf bottom surface respectively with a minor normal component

synthetic aperture radar interferometry to measure earth s surface topography and its deformation synthetic aperture radar interferometry insar from earth orbiting spacecraft provides a new tool to map global topography and deformation of the earth s surface radar images taken from slightly different viewing directions allow the construction of digital elevation models of meter scale accuracy these data sets aid in the analysis and interpretation of tectonic and volcanic landscapes if the earth s surface deformed between two radar image acquisitions a map of the surface dis placement with tens of meters resolution and subcentimeter accuracy can be con structed this review gives a basic overview of insar for earth scientists and presents a selection of geologic applications that demonstrate the unique capabilities of insar for mapping the topography and deformation of the earth

a comparison of the sedimentary records of the 1960 and 2010 great chilean earthquakes in 17 lakes implications for quantitative lacustrine palaeoseismology seismically induced event deposits embedded in the sedimentary infill of lacustrine basins are highly useful for palaeoseismic reconstructions recent well documented great megathrust earthquakes provide an ideal opportunity to calibrate seismically induced event deposits for lakes with different characteristics and located in different settings this study used 107 short sediment cores to investigate the sedimentary impact of the 1960 mw 9 5 valdivia and the 2010 mw 8 8 maule earthquakes in 17 lakes in south central chile i e lakes negra lo encanado aculeo vichuquen laja villarrica calafquen pullinque pellaifa panguipulli neltume rinihue ranco maihue puyehue rupanco and llanquihue a combination of image analysis magnetic susceptibility and grain size analysis allows identification of five types of seismically induced event deposits i mass transport deposits ii in situ deformations iii lacustrine turbidites with a composition similar to the hemipelagic background sediments lacustrine turbidites type 1 iv lacustrine turbidites with a composition different from the background sediments lacustrine turbidites type 2 and v megaturbidites these seismically induced event deposits were compared to local seismic intensities of the causative earthquakes eyewitness reports post earthquake observations and vegetation and geomorphology of the catchment and the lake megaturbidites occur where lake seiches took place lacustrine turbidites type 2 can be the result of i local near shore mass wasting ii delta collapse iii onshore landslides iv debris flows or mudflows or v fluvial reworking of landslide debris on the contrary lacustrine turbidites type 1 are the result of shallow mass wasting on sublacustrine slopes covered by hemipelagic sediments due to their more constrained origin lacustrine turbidites type 1 are the most reliable type of seismically induced event deposits in quantitative palaeoseismology because they are almost exclusively triggered by earthquake shaking moreover they most sensitively record varying seismic shaking intensities the number of lacustrine turbidites type 1 linearly increases with increasing seismic intensity starting with no lacustrine turbidites type 1 at intensities between v and vi and reaching 100 when intensities are higher than vii combining different types of seismically induced event deposits allows the reconstruction of the complete impact of an earthquake

earthquake deformations in the lisan deposits and seismotectonic implications summary earthquake deformations and induced sedimentary structures preserved in quaternary sediments include faults folds fissures slumps sand boils and other effects of liquefaction such deformations and structures are well preserved in the lisan deposits of the dead sea of most importance are the fold type deformations known as decollement structures which are present all along the eastern side of the lisan and seem to decrease gradually westwards to disappear in the middle of the lisan these may indicate that palaeoearthquakes originating along the araba fault have triggered such structures due to shaking of elastoplastic unconsolidated sediments over gentle slopes dipping to the west preliminary results from studies on decollement structures preserved in a section representing some 1733 years of continuous deposition in the uppermost pleistocene in the vicinity of wadi araba indicate that 1 seismic activity has fluctuated with time average recurrence period is about 340 20yr for earthquakes with magnitudes greater than or equal to 6 5 earthquakes with magnitude greater than 7 seem to have occurred along the araba fault 2 deduced earthquake magnitudes conform to the frequency magnitude relationship log n 5 24 0 68m 3 the deduced seismic slip rate along the araba fault seems to be not less than 0 64 0 04 cm yr 1

geodetic teleseismic and strong motion constraints on slip from recent southern peru subduction zone earthquakes we use seismic and geodetic data both jointly and separately to constrain coseismic slip from the 12 november 1996 m w 7 7 and 23 june 2001 m w 8 5 southern peru subduction zone earthquakes as well as two large aftershocks following the 2001 earthquake on 26 june and 7 july 2001 we use all available data in our inversions gps interferometric synthetic aperture radar insar from the ers 1 ers 2 jers and radarsat 1 satellites and seismic data from teleseismic and strong motion stations our two dimensional slip models derived from only teleseismic body waves from south american subduction zone earthquakes with m w 7 5 do not reliably predict available geodetic data in particular we find significant differences in the distribution of slip for the 2001 earthquake from models that use only seismic teleseismic and two strong motion stations or geodetic insar and gps data the differences might be related to postseismic deformation or more likely the different sensitivities of the teleseismic and geodetic data to coseismic rupture properties the earthquakes studied here follow the pattern of earthquake directivity along the coast of western south america north of 5 s earthquakes rupture to the north south of about 12 s directivity is southerly and in between earthquakes are bilateral the predicted deformation at the arequipa gps station from the seismic only slip model for the 7 july 2001 aftershock is not consistent with significant preseismic motion

evidence from lake lisan of solar influence on decadal to centennial scale climate variability during marine oxygen isotope stage 2 documentation of short term climate variability during the glacial period has been limited by the availability of well dated high resolution archives here we present a paleoclimate reconstruction from varved lacustrine sediments of lake lisan dead sea rift for ca 26 2 17 7 calendar ka the age is based on a floating varve chronology anchored to radiometric dates our reconstruction indicates that small ice rafting events a b c and d as well as heinrich events in the north atlantic are associated with the eastern mediterranean arid intervals study of seasonal sublaminae yields evidence of several additional decadal to century scale arid events that correlate with cooler temperatures at higher latitudes analyses in the frequency domain indicate the presence of periodicities centered at 1500 yr 500 yr 192 yr 139 yr 90 yr and 50 60 yr suggesting a solar forcing on climate

fault geometry at the rupture termination of the 1995 hyogo ken nanbu earthquake the source geometry and slip distribution at rupture termination of the 1995 hyogo ken nanbu earthquake were investigated using waveform inversion on the assumption of fault branching in the northeastern part of the rupture model possible branching of the okamoto fault is suggested both by the static displacement distribution and damage extension east of kobe nishinomiya area to exclude data contaminated by the basin edge diffracted wave in the waveform inversion process we examined the spatio temporal variation of its influence and from a comparison with a flat model we determined windows appropriate for the data three subevents were identified as was reported in previous works the largest was in the shallow part on the awaji side whereas the smaller two occurred at great depths 7km on the kobe side we found a smaller subevent in the deep part of the branch total variance reduction was larger and the abic value was smaller when we assumed the branch than when we did not which shows the superiority of the branching fault model resolution checks showed that the slips on proposed branched portions are physical and not caused by random data noise or systematic errors in green s func tions that arise from misestimation of velocity structures calculation of the relative static displacement between two leveling observation stations near the branching fault also showed the greater utility of the branching fault model the effect of slip on the branched fault has been shown in near source ground motion simulation using the 3d finite difference method iwata et al 1999 the characteristic distribution of ground motion in the near source region indicated by the damage distribution is well reproduced by the modeling of both the source process and wave propagation in the realistic 3d velocity structure slip on the branched fault affected the ground motion in eastern kobe nada and higashi nada wards ashiya and nishinomiya cities but its contribution is not dominant even in those regions about 30 to 50 maximum velocity in the frequency range of 0 1 to 1 0 hz we conclude that branching rupture of the okamoto fault during the hyogo ken nanbu earthquake is the preferable interpretation on the source process of this earth quake this supports the idea of a geometrical barrier suggested by geological ob servations

documentation of earthquake induced disturbance of lake sediments using subbottom acoustic profiling subbottom acoustic profiling in lakes on the canadian shield and in the canadian cordillera has revealed disruptions in deltaic and lacustrine sediments that can be attributed to large historical earthquakes the timiskaming earthquake of 1935 magnitude 6 25 and the vancouver island earthquake of 1946 magnitude 7 2 triggered extensive slumping and flow of postglacial sediments in lakes located within a few tens of kilometres of the epicentres of these events there is some evidence in one of the surveyed lakes for in situ mobilization of sediment on relatively gentle slopes with minimal horizontal displacement this may be a product of liquefaction induced by coseismic shaking or displacements along faults beneath the basin in another lake widespread coseismic slumping resuspended large amounts of fine sediment which then settled out onto the lake floor to produce a texturally anomalous layer features similar to those produced by the 1935 and 1946 earthquakes can also result from a variety of non

calibration of the 14c time scale to 40 ka by 234u 230th dating of lake lisan sediments last glacial dead sea a new comparison of 14c dates with 234u 230th ages is presented of aragonites from lake lisan the last glacial dead sea between 20 52 cal ka bp the lisan data are coincident with the coral based 14c calendar age calibration through the continuous portion of the curve to 23 5 cal ka bp and with the additional checkpoints at 30 and 40 cal ka bp the agreement with the corals provides evidence for the accuracy of the u th and 14c ages and indicates that lisan aragonites can potentially be used to generate a nearly continuous record of the atmospheric 14c variations through this crucial time interval the lisan data are compared with other records older than 25 cal ka bp from lake suigetsu japan north atlantic foraminifera south african cave deposits and tufa from spain over some age intervals the records show broad agreement over other intervals they diverge all agree that 14c ages were 2 5 0 5 ka younger than calendar ages between 20 32 cal ka bp for ages 32 cal ka bp the lake suigetsu data indicate small differences between 14c ages and calendar ages of less than 1 5 ka the other records broadly agree that 14c ages are too young by 3 1 ka from 32 39 cal ka bp at 40 cal ka bp the foraminifera show equal 14c and calendar ages while the corals lisan aragonites and the spanish tufa indicate a large age difference of 4 5 ka a recent paleomagnetic study of the lisan formation indicates that the high calendar 14c age difference at 40 cal ka bp may be associated with the laschamp paleomagnetic excursion

extracting damages caused by the 2008 ms 8 0 wenchuan earthquake from sar remote sensing data abstract bad weather conditions usually limit the acquisition of optical remote sensing images while all day and all weather synthetic aperture radar sar shows the ability of providing timely remote sensing data for emergency response and rescue works after earthquake because sar is sensitive to the surface changes caused by earthquake the modified electromagnetic behaviour by geological disasters and the collapse of buildings can be recorded in sar images as backscattering intensity changes absolute radiometric calibration was performed to sar products to derive backscattering coefficient sigma nought from image digital number dn based on change detection methods advanced land observing satellite alos phased array type l band synthetic aperture radar palsar data and terrasar x data acquired for the ms 8 0 wenchuan earthquake were used to extract earthquake damage information this study revealed that landslides showed stronger backscattering and barrier lakes showed lower backscattering in post earthquake 10 m alos palsar images comparing to pre earthquake and collapsed buildings showed lower backscattering compared to un collapsed buildings in 1 m terrasar x image results showed that sar data with different spatial resolutions are useful for different earthquake damage information extraction medium spatial resolution sar data e g 10 m alos palsar data were efficient for secondary geological disaster extraction high resolution sar data e g 1 m terrasar x data with the help of ancillary gis data or high resolution optical data could be used to extract building collapse information in urban areas this study indicates that sar remote sensing data can provide earthquake damage information at early emergency stage and assist the field surveying further damage assessment and post earthquake reconstruction

soft sediment deformation structures interpreted as seismites in middle late pleistocene aeolian deposits apulian foreland southern italy abstract soft sediment deformation structures in middle late pleistocene deposits of torre san gennaro brindisi southern italy have been analysed from a morphologic point of view the deformational structures are represented by deformed cross bedding and large injection structures they are restricted to aeolian sediments and the mechanism of deformation is related to liquefaction and or fluidization processes the liquefaction and or fluidization processes have been interpreted as seismic induced after consideration of all other possible trigger agents the discussion about the possible source areas of the palaeoseismic event was carried out through the analysis both of the general magnitude distance relations and the main structural features of the study zone in conclusion we consider the key criteria for trigger mechanism interpretation of soft sediment deformation structures in aeolian deposits and the actual feasibility of using aeolian sediments for the palaeoseismic studies

offshore sedimentary effects of the 12 january 2010 haiti earthquake although the 12 january 2010 haiti earthquake was one of the deadliest earthquakes in history it left no clear geological evidence of rupture on land as a tectonic event the earthquake was complex even the faults involved remain unclear using geophysical and coring data we document direct evidence of the sedimentation generated by the catastrophic 12 january 2010 earthquake offshore these studies document submarine paleoseismology methods that can be used for assessing seismic risk in this and other tectonic settings such as the california san andreas fault where deeper buried blind thrusts may exist shaking by the 12 january main shock triggered sediment failures and turbidity currents from coastal sources to deep water sinks an 0 05 km 3 turbidite was deposited in the canal du sud basin 1750 m water depth over 50 km 2 almost 2 months after the main shock a 600 m thick sediment plume was still present in the lowermost water column at this location the turbidite was time correlated to the 12 january earthquake by the excess 234 th in the sediments with a half life of 24 days its presence documents an infl ux of terrigenous sediment mixing with marine sources derived from the basin slopes this turbidite and older ones observed beneath it displays complex cross bedded and fi ning upward stratigraphy indicative of long waves and seiche oscillations that are consistent with locally reported tsunamis this 12 january sedimentary record highlights the potential for submarine paleoseismology to unravel the seismic history of continental transform boundaries such as the enriquillo plantain garden fault in the dominican republic haiti and jamaica as well as other tectonic settings where no clear land based evidence for a rupture exists

synthetic aperture radar interferogram of the 1995 kobe earthquake and its geodetic inversion crustal deformation from the mw 6 9 january 17 jst 1995 kobe japan earthquake was detected by synthetic aperture radar interferometry sar more than four fringes with ellipsoidal shape were observed surrounding the nojima fault on northern awaji island suggesting a shortening in the range of more than 11 75 4 cm on the east side of this fault the sar sensor shows ellipsoidal fringes with an uplift zone in the rokko mountain range and sharp subsidence around the kobe area in addition to sar interferometry leveling and gps surveys were conducted by the geographical survey institute of japan gsi the permanent gps observation sites of the gsi monitored ground displacements from this earthquake with daily updates based on these geodetic data we estimated the faulting mechanism of the earthquake the analytical procedure was an iterative linearized least squares method a multi fault system consisting of six subfaults was constructed the locations of the estimated model faults were close to those of the active faults in this area running from the nojima fault on awaji island to the rokko faults in the kobe area with a change in strike angle near the ohtsuki fault in the kobe area the slip vectors of the nojima fault on awaji island had a large component of reverse dip slip of about 2 m and strike slip of about 2 m in the kobe area the amount of slip ranged from 0 3 to 1 2 m and was small compared with the slip on the nojima fault the results of these slip vectors agreed well with the results of other seismic geodetic and field studies

joint inversion of insar gps teleseismic and strong motion data for the spatial and temporal distribution of earthquake slip application to the 1999 izmit mainshock the space time distribution of slip of the 17 august 1999 izmit earthquake is investigated by inverting synthetic aperture radar sar interferometry and global positioning system gps data together with teleseismic broadband and near field strong motion records surface offsets are used as an added constraint special emphasis is given to analysis of the resolution of the different data sets we use a four segment finite fault model and a nonlinear inversion scheme allowing slip to vary in amplitude direction and duration as well as variable rupture velocity from the inversion of synthetic data we find that the best spatial resolution can be expected in the upper half of the fault model above 12 km where coverage of the interferometric sar data is good western half of the rupture and near the gps and strong motion stations teleseismic data are found to have a lower resolution that is more evenly distributed over the fault model the joint inversion of all the data sets has an increased resolving power compared with the separate inversions and gives a more robust description of the space and time distribution of slip our study shows the importance of resolution tests in evaluating the reliability of earthquake kinematic models and it confirms that an excellent fit of a single kind of data does not necessarily imply a good retrieval of the kinematic properties of an earthquake the izmit rupture which is almost pure right lateral strike slip faulting is dominated by the bilateral breaking of a central asperity located between 29 7 e about 10 km west of the city of golcuk and 30 4 e eastern margin of sapanka lake with slip reaching 6 8 m in the depth range 6 12 km the western termination of the rupture is found near the city of yalova but large slip ends around 29 7 e about 10 km east of hersek delta a second area of large slip is required by all the data sets further east toward the city of duzce between 30 7 e and 31 1 e karadere and duzce faults this eastern slip zone which is separated from the main central asperity by an area of greatly reduced slip is less well constrained by the data however a strong motion station near the city of duzce helps to locate a high slip patch near 31 1 e in the depth range 6 12 km the total seismic moment resulting from the joint inversion is 2 4 1027 dyne cm most of the energy release occurred in a short time less than 15 sec corresponding to the bilateral breaking of the central asperity rupture propagation is relatively uniform and fast toward the west with a rupture velocity close to 3 5 km sec propagation of large slip toward the east is initially slower but it accelerates during a short time interval about 10 sec after rupture nucleation eastward progression then slows down to less than 2 km sec after 15 sec and rupture almost vanishes in amplitude ca 20 sec after initiation rupture propagation then proceeds on the easternmost karadere and duzce fault segments east of 30 7 e from 22 to ca 50 sec supershear rupture propagation is not required for modeling the waveforms considered in this study the hypocenter of the duzce earthquake which occurred 3 months later 12 november 1999 m w 7 2 is located in the immediate vicinity of the easternmost slip patch of the izmit earthquake manuscript received 28 july 2000

the record of historic earthquakes in lake sediments of central switzerland deformation structures in lake sediments in central switzerland can be attributed to strong historic earthquakes the type and spatial distribution of the deformation structures reflect the historically documented macroseismic intensities thus providing a useful calibration tool for paleoseismic investigations in prehistoric lake sediments the swiss historical earthquake catalogue shows four moderate to strong earthquakes with moment magnitudes of mw 5 7 to mw 6 9 and epicentral intensities of i0 vii to i0 ix that affected the area of central switzerland during the last 1000 years these are the 1964 alpnach 1774 altdorf 1601 unterwalden and 1356 basel earthquakes in order to understand the effect of these earthquakes on lacustrine sediments four lakes in central switzerland sarner see lungerer see baldegger see and seelisberg seeli were investigated using high resolution seismic data and sediment cores the sediments consist of organicand carbonate rich clayey to sandy silts that display fine bedding on the centimeter to millimeter scale the sediments are dated by historic climate and environmental records 137 cs activity and radiocarbon ages deformation structures occur within distinct zones and include large scale slumps and rockfalls as well as small scale features like disturbed and contorted lamination and liquefaction structures these deformations are attributed to three of the abovementioned earthquakes the spatial distribution of deformation structures in the different lakes clearly reflects the historical macroseismic dataset lake sediments are only affected if they are situated within an area that underwent groundshaking not smaller than intensity vi to vii we estimate earthquake size by relating the epicentral distance of the farthest liquefaction structure to earthquake magnitude this relationship is in agreement with earthquake size estimations based on the historical dataset d 2004 elsevier b v all rights reserved

long term earthquake clustering a 50 000 year paleoseismic record in the dead sea graben the temporal distribution of earthquakes in the dead sea graben is studied through a 50 000 year paleoseismic record recovered in laminated sediments of the late pleistocene lake lisan paleo dead sea the lisan represents more than 10 times the 4000 years of historical earthquake records it is the longest and most complete paleoseismic record along the dead sea transform and possibly the longest continuous record on earth it includes unique exposures of seismite beds earthquake induced structures associated with slip events on syndepositional faults the seismites are layers consisting of mixtures of fragmented and pulverized laminae the places where the seismites abut syndepositional faults are interpreted as evidence for their formation at the sediment water interface during slip events on these faults thicker sediment accumulation above the seismites in the downthrown blocks indicates that a seismite formed at the water sediment interface on both sides of the fault scarps modern analogs and the association with surface ruptures suggest that each seismite formed during a m l 5 5 earthquake the 230 th 234 u ages of a columnar section obtained by thermal ionization mass spectrometry give a mean recurrence time of 1600 years of m l 5 5 earthquakes in the dead sea graben the earthquakes cluster in 10 000 year periods separated by quiet periods of similar length this distribution implies that a long term behavior of the dead sea transform should be represented by a mean recurrence of at least 20 000 year record this observation has ramifications for seismic hazard assessment based on shorter records

u th dating of lake lisan late pleistocene dead sea aragonite and implications for glacial east mediterranean climate change u series dating can be an effective means to obtain accurate and precise ages on quaternary carbonates however most samples require a correction for u and th in admixed detritus this complication is often addressed through generation of u th isochrons requiring analyses of several coeval samples in addition presence of water derived hydrogenous th in the carbonate can cause inaccuracies in isochron ages this study reports a high resolution u series chronology of sediments deposited by lake lisan the last glacial precursor of the dead sea the strategy employed combines multiple measurements from a few stratigraphic heights and fewer analyses from many heights in a single described and measured section the resulting chronology is based on ages at 22 heights in a 40 m thick section covering the interval of 70 14 calendar ka bp the effects of admixed detritus are evaluated using trace elements nearly pure aragonite samples indicated by very low abundances of insoluble elements such as nb and zr were found to contain hydrogenous th which causes the uncorrected u 230th age of a modern sample to be 2 5 ka nevertheless accurate ages have been obtained by correcting for the detrital and aqueous interferences the resulting ages are in stratigraphic order and their accuracy is evidenced by consistency of lisan formation u series and 14c ages with the coral based calendar radiocarbon age calibration the u th ages provide a context to unravel the limnological history of lake lisan boundaries between the lower middle and upper stratigraphic units correspond to the mis 4 3 and 3 2 transitions respectively during mis 2 and 4 the lake generally showed a stable two layer configuration and a positive fresh water balance reflected by deposition of laminated aragonite detritus dry intervals during mis 2 and 4 are indicated by thick gypsum layers and an inferred depositional hiatus which are temporally associated with heinrich events h1 at 17 ka and h6 at 65 ka respectively during mis 3 the lake level was unstable with intermittent dry periods indicated by abundant clastic layers and a significant hiatus between 43 49 ka clastic layers are associated with dansgaard oeschger events during mis 3 and indicate lake level declines during abrupt northern hemisphere warmings overall the climate of the eastern mediterranean region shows a strong linkage to the northern hemisphere climate with increasing lake size and stability during cold periods and fluctuations and dessication during warmings and heinrich events

giant earthquakes in south central chile revealed by holocene mass wasting events in lake puyehue abstract very high resolution reflection seismic profiling 3 5 khz revealed nine holocene mass wasting events in lake puyehue south central chile these events are made up of numerous coeval mass wasting deposits and some homogenites which are radiocarbon dated the two youngest mass wasting events could be attributed to the giant ad 1960 and ad 1575 valdivia earthquakes the most extensive event took place around 1660 cal yr bp evaluation of all possible slope failure processes led us to infer that giant earthquakes roughly comparable to the ad 1960 valdivia earthquake mw 9 5 are the most likely trigger mechanisms of all mass wasting events in lake puyehue these occurred with a mean recurrence rate of 1000 yr although relatively aperiodically ranging between 500 and 2000 yr quantitative comparison of mass wasting events related to historically reported earthquakes ad 1960 and ad 1575 showed significant differences although these earthquakes are assumed to have had a comparable strength a lowered background sedimentation rate could be responsible for this variable earthquake recording which highlights the importance of a thorough assessment of the depositional history before using lacustrine records for quantitative paleoseismic analysis

recurrence pattern of holocene earthquakes along the dead sea transform revealed by varve counting and radiocarbon dating of lacustrine sediments abstract a high resolution holocene seismic history of the dead sea transform dst is established from laminated sedimentary cores recovered at the shores of the dead sea radiocarbon dating and annual laminae counting yield excellent agreement between disturbed sedimentary structures identified as seismites and the historical earthquake record all recent and historical strong events of the area were identified including the major earthquakes of a d 1927 1837 1212 1033 749 and 31 b c the total of 53 seismites recognized along the entire holocene profile indicate varying recurrence intervals of seismic activity between a few and 1000 years with a conspicuous minimum rate at 2100 31 b c and a noticeable maximum during the past six to eight centuries most of the epicenters of the correlated earthquakes are situated very close to the dead sea within 150 km or up to 400 km north of it along the dst between 1000 b c and a d 1063 and from a d 1600 to recent time the epicenters are all located on the northern segment of the dst whereas prior to 1000 b c and between a d 1000 and 1600 they appear to scatter along several segments of the dst we establish how the local intensity exerts a control on the formation of seismites at historically estimated intensities greater than vii all well documented earthquakes are correlated whereas at intensities smaller than vi none are matching the periods with enhanced earthquake rate along the dst correlate with those along the north anatolian fault as opposed to the intervening east anatolian fault this may indicate some elastic coupling on plate boundary scale that may also underlie escape and extrusion tectonics typical of continental collision