temporal variability in currents and the benthic boundary layer at an abyssal station off central california abstract current meter records from seven sequential moorings were collected during 1993 1996 at an abyssal station off central california sta m 4100 m depth the entire 2 1 4 yr time series of the flow at 600 50 and 2 5 m above bottom above near the top of and within the benthic boundary layer were analyzed for mean flow statistics and subtidal and tidal variability the mean current vectors at each altitude were southward at profiles of light transmission and potential temperature collected intermittently during the 2 1 4 yr period showed that the benthic mixed layer at sta m extended on average 40 m above bottom range 15 80 mab evidence for local resuspension of recently deposited detritus came from time lapse photographs of the sea floor that showed a period of near bottom turbidity that corresponded to a period of high near bottom flow however rough estimates of friction velocity indicated that the bed stress usually was too low at sta m to cause local resuspension of sediments we hypothesize that the observed benthic mixed layers contained suspended particles advected from more energetic areas to the north of sta m

the chronostratigraphy of a quaternary sequence at the distal part of the nile littoral cell haifa bay israel the current detailed chronostratigraphic framework of the last 1 ma of an eastern mediterranean sequence haifa bay israel aims to examine the relative roles of sea level changes climate and tectonics seven continuous marine cores up to 120 m long were recovered from shallow water depths the cores were dated by optically stimulated luminescence 14 c magnetostratigraphy 230 th 234 u 26 al 10 be occurrence of index fossils and correlated to the global sea level curve and marine isotope stages mis the sedimentary sequence accumulated during the last ca 1 0 ma consists of 21 transgression regression units with hiatuses between them five marine terrestrial cycles which occur in the lower part of the sequence are attributed to the jaramillo subchron and the brunhes matuyama boundary and correspond to mis 29 21 the top 50 m includes three sedimentary cycles deposited in the last ca 400 ka the regressive phases during this interval correspond to glacial mis 8 6 and 2 while the transgressions correspond to interglacial mis 11 7 5 and 1 thus for the first time this study documents the longest quaternary succession dated so far in a key area of the levant sensitive to global history of sea level changes and glacial interglacial fluctuations copyright 2012 john wiley sons ltd

measurement of porosity in natural sand desposits the proposed technique enables porosity measurement to be made on undisturbed samples taken from sand deposits it is based on the impregnation and hardening of sand in the field and the preparation of small cube samples which are tested in the laboratory the method proved successful in both dry and wet sand its application is demonstrated in the study of porosity variations in a dune the internal structure of the dune was studied by means of replicas or peels which reveal in detail the layering of the dune sand a definite relationship was established between porosity and relative density of the sand and its internal structure and mode of deposition very high densities were found in sand deposited by accretion on the dune s back relative densities in accretion deposits approach and even exceed 100 percent

directional wave measurement at haifa israel and sediment transport along the nile littoral cell abstract results of three years of directional wave measurement at the eastern mediterranean coast of haifa israel are presented the wave height and energy flux distributions reveal a moderately high energy coast with a bimodal annual cycle the rate of wave induced longshore sediment transport is estimated from the directional energy flux distributions it describes an annual cycle with a maximum northward transport of 75 14 10 3 m 3 month in midwinter and a southward transport of 26 5 10 3 m 3 month in summer the net annual transport is northward and computed at 110 100 10 3 m 3 yr we show that a wave induced transport is sufficient in explaining the apparent transport of sediments in the nile littoral cell from the nile delta source to the haifa bay sink

sediment flux dynamics over the shallow 25 m depth shelf of the mediterranean sea along the israeli coast abstract in order to study the dynamics of sediment fluxes at the northern end of the nile littoral cell sediment traps were deployed for one year over the shallow shelf of the mediterranean sea offshore israel the sediment traps replaced monthly were suspended on a mooring line two kilometers offshore of the hadera power station 10 m above a 25 m deep seafloor sea state conditions near the traps were measured by an acoustic doppler profiler that provided the bottom water temperature wave heights and current s velocities and direction the measured sediment fluxes greatly varied between sampling periods with a minimum value of 1 8 g m 2 d 1 in autumn and a maximum value of 83 g m 2 d 1 in winter this variation was mostly effected by wave induced resuspension of sediment a strong correlation r2 0 97 was found between integrated wave heights that exceeded 1 5 m and the measured sediment fluxes based on the sea state conditions and sediment trap data we conclude that the direction of sand transport at the study area was strictly northwards and that almost all of the annual sand transport occurred during several high energy events in the winter fine particles that consisted the majority of the mass flux were absent in the underlying 25 m deep seafloor suggesting that they are very effectively winnowed off beyond the sand strip

morphological patterns of southeastern mediterranean river mouths the topographic setting of the beach as a forcing factor abstract israeli mediterranean river mouths are characterized by an extremely dynamic morphology as their channels tend to migrate hundreds of meters north and south along the shoreline this study aims to characterize the impact of the topographic setting of the beach on the dynamic morphology of seven of these river mouths this was achieved by morphologically mapping and monitoring the natural channel dynamics of each mouth over time recognizing their spatial and temporal migration and avulsion patterns describing generalizing and classifying the different types of river mouths present on the coast and investigating the influence of the adjacent topography on their morphology detailed geomorphologic mapping was achieved using remote sensing and gis techniques utilizing more than 300 aerial photographs taken between 1918 and 2005 this study revealed a number of typical differences in these patterns attributed to differences in the topographic setting of the beach in the vicinity of the mouths elongated strip topography coasts demonstrate a uniform slope beach with equally spaced elevation contours forming a narrow sandy strip between the shoreline and the back berm funnel topography coasts exhibit a non uniform slope with a funnel shaped topographic depression adjacent to the river mouth similarities were found between the spatial and the temporal morphological patterns of river mouths flowing in each of these two topographical settings elongated strip mouths are deflected alongshore a barrier and demonstrate high migration distances and little temporal change the morphology of funnel mouths was found to be highly temporally variable yet less spatially dynamic as these mouths channels are restricted by their funnel topography this study concludes that the topographic setting of the beach a constant element in the temporal scale of this study is a primary factor influencing the morphology of the studied mouths

middle and late holocene sea levels along the israel mediterranean coast evidence from ancient water wells during the course of a study of historical water wells along the israeli shore which has been in progress since 1984 an innovative method for investigating sea level fluctuations was developed eighteen ancient water wells were re dug 14 by the author and four by archaeologists most of the re dug wells are found at archaeological sites located a very short distance inland from the present shoreline evidence of ancient ground water levels found in the wells directly reflects on historic eustatic sea level changes and the rate at which the end of the post glacial transgression advanced a critical question concerns the durability and life span of these wells as the true age is very important for the accurate reconstruction of a sea level curve the pre pottery neolithic well of atlit yam which is the oldest known well in the world ca 8000 yr old enabled the most accurate sea level reconstruction for early holocene times sea level rise during that period of the atlit yam site was of the order of 20 mm yr 1 at the beginning slowing to 6 8 mm yr 1 at the abandonment of this site at ca 7 5 ka bp when it was flooded by the advancing and rising sea after reaching its present level sea level fluctuations for the past 2 5 millennia were not greater than 1 5 to 2 m 1997 john wiley sons ltd

holocene sea level changes along the mediterranean coast of israel based on archaeological observations and numerical model local sea level curves reflect global eustatic changes regional isostatic adjustments of the crust to changing ice and ocean volumes and tectonically controlled crustal movements in this study we evaluate the relative contribution of each of these factors to the holocene sea level curve of the mediterranean coast of israel we use archaeological data as constraints on palaeo sea levels and we then compare the observational limits with isostatic models for sea level change across the region the isostatic model includes the contribution arising from the relative minor increase in ocean volumes for the past 6000 years due to residual melting of ice sheets the effect of the changing shape of the ocean basin the time dependence of shorelines as sealevel changes and the changing surface area occupied by ice sheets differences if significant between the observed and predicted change are interpreted as being of tectonic origin the archaeological observations and the model sea level curve along the mediterranean coast of israel were found to be generally consistent and any discrepancies lie within the uncertainties of both values our model predicted that 8000 years ago sea level at the israel coast was at about 213 5 2 m whereas the archaeological data place it at 216 5 1 m by 7000 bp the predicted level has risen to about 27 1 m consistent with the archaeological evidences according to both observations and predictions sea level was still lower than 2 3t o24 5 m at 6000 bp and remained below its present level until about 3000 2000 bp the comparison between the model sea level curve and the archaeological observations also enable to conclude that the average rate of vertical tectonic movement for the last 8000 years at the carmel coast israel has been less than 0 2 mm year q 2001 elsevier science b v all rights reserved

deglacial sea level record from tahiti corals and the timing of global meltwater discharge the timing of the last deglaciation is important to our understanding of the dynamics of large ice sheets1 and their effects on the earth s surface2 3 moreover the disappearance of the glacial ice sheets was responsible for dramatic increases in freshwater fluxes to the oceans which probably disturbed the ocean s thermohaline circulation and hence global climate4 7 sea level increases bear witness to the melting of continental ice sheets but only two such records from barbados8 9 and new guinea10 11 corals have been accurately dated but these corals overlie active subduction zones where tectonic movements are large and often discontinuous especially in new guinea so the apparent sea level records may be contaminated by a complex tectonic component here we date fossil corals from tahiti which is far from plate boundaries and thus is likely to be tectonically relatively stable and remote from the locations of large former ice sheets the resulting record indicates a large sea level jump shortly before 13 800 calendar years bp which corresponds to meltwater pulse 1a in the barbados coral records8 9 the timing of this event is more accurately constrained in the tahiti record revealing that the meltwater pulse coincides with a short and intense climate cooling event12 15 that followed the initiation of the bolling allerod warm period12 16 but preceded the younger dryas cold event by about 1 000 years

quaternary subsurface paleosols in haifa bay israel a new perspective on stratigraphic correlations in coastal settings abstract this study presents the first in depth analysis of properties micromorphology clay mineralogy magnetic susceptibility and general properties of quaternary paleosols from two boreholes in haifa bay subsurface whose chronostratigraphic position was determined previously the current analytical results allowed us to identify the type hydrologic regime polygenesis mode of pedosedimentary evolution and some subsequent alterations of paleosols the analogs of polygenic haplo and rhodo xeralf soils brown mollic and ortho hamra are associated with marine isotope stages mis 3 1 5 4 6 and 8 0 or 7 4 and likely developed in response to a changing climate paleosols prior to mis 12 yet difficult to attribute to specific mis are distinct from hamra soils by striking mottling poor preservation of argillic horizons abundant deformations in microfabric and overprinting processes of gley and calcium carbonate accumulation it is assumed that calcification may have affected the earlier formed clay illuviation and amorphous features and was related with marine coastal groundwater interface the older calcic gleyed paleosols of earlier middle pleistocene likely indicate that coastal paleogeography was characterized by both high discharge of the ancient qishon river and a high water table the thin section micromorphology is particularly valuable for refined paleopedological taxonomy identified pleistocene paleosols including their type hydrology and mode of evolution are proposed to serve additional stratigraphic markers in coastal settings

a new chalcolithic era tsunami event identified in the offshore sedimentary record of jisr al zarka israel abstract tsunami field evidence is a critical resource for determining coastal risk however in many cases there is low potential for long term preservation of such deposits on land a growing body of evidence suggests that tsunami deposits can be present in the shallow offshore realm and may present a largely untapped but important worldwide sedimentological reference set for investigating past tsunami events here different proxies for tsunami sediment identification and differentiation granulometry xrd xrf ft ir were used to determine the presence or absence of such deposits in a core collected offshore at jisr al zarka midway between tel aviv and haifa the study aimed to recognize anomalous deposits and test different analytical methods to define their origins five anomalous sedimentological horizons were identified four of which were interpreted as tsunamigenic by comparison to previously identified poorly sorted shell rich tsunamites found nearby in caesarea and contrast to the fine sand nile derived background sediments the remaining anomaly was distinctive but not determined to be tsunamigenic due to a lack of coarse shell in the matrix the oldest tsunamigenic layer coinciding with the chalcholithic cultural period 5 7 ka is the oldest such deposit identified offshore israel to date and the non tsunamigenic anomalous horizon may correspond with a transitional climatic phase 5 5 ka this research reinforces the importance of offshore investigations as a means of improving tsunami catalogues and identifying environment altering events

sediment transport mechanisms revealed by quantitative analyses of seafloor morphology new evidence from multibeam bathymetry of the israel exclusive economic zone abstract this study synthesizes 15 years 2001 2016 of detailed multibeam hydrographic mapping covering the entire 26 500 km2 of the israeli exclusive economic zone eez multibeam data were collected on board three research vessels across the continental shelf slope and the deep levant basin between water depths of about 15 m to 2100 m single channel 3 5 khz seismic reflection chirp profiles were collected simultaneously with the multibeam surveys in selected parts of the area the new data enabled the first comprehensive quantitative seafloor morphological analysis of the slope and deep basin using gis techniques on the high resolution multibeam data we analyze the spatial distribution and quantitatively describe the seafloor morphologies in detail high resolution chirp seismic profiles demonstrate the underlying shallow structure results indicate that the seabed comprises five main morphologies folds faults sediment waves deepwater channels and sediment fan lobes quantitative morphological analysis and seismic data interpretation were used to derive field relations between these morphologies which along with previously collected multi channel seismic reflection data suggest that a concentric fold geometry formed around the nile outlet during the late pliocene to early pleistocene as part of a general thin skin radial salt tectonic deformation above the messinian mobile unit this radial motion was accompanied by displacement along nne trending strike slip faults in the basin and an extensional component across e w trending strike slip faults along the levant margin while some of these displacements continue to deform the modern seabed across area a others are covered by a wedge of quaternary deposits mainly in the northeastern part of the basin area b areas a and b also differ in grain size distribution as indicated by backscatter analysis of the multibeam data these observations divide the israeli eez into two distinct areas area a nile derived siliciclastic sediments transported directly into the deep basin via confined forming meandering channels and overbank deposits and unconfined flows forming fans and lobes the wedge consisting of area b was fed by erosion products of the nile outlet that were transported northwards along the continental shelf by seafloor currents of the levant jet system and glided down the northern levant continental slope as turbidity currents this supply built at least seven sequences of quaternary sediment waves that form upslope migrating cyclic steps the complete data coverage and quantitative morphological analysis presented here introduce new spatial and temporal constraints that call for a reexamination of previous seabed sampling locations not accounting for detailed bathymetry and to augment future seabed sampling efforts understanding the sediment supply paths across the basin and the geomorphological footprint of salt tectonics processes

particle fluxes induced by benthic storms during the 2012 dense shelf water cascading and open sea convection period in the northwestern mediterranean basin abstract the effects of deep dense shelf water cascading and open sea convection on the sediment dynamics of the northwestern mediterranean basin were studied by near bottom moored instruments recording trapped particle fluxes suspended particle fluxes water properties and hydrodynamics from november 2011 to july 2012 during this period near bottom currents induced by winter dense water formation generated benthic storms that caused resuspension at 2450 m water depth increasing by more than one order of magnitude the ambient suspended sediment concentrations the trapped particle fluxes and the suspended sediment fluxes during the preconditioning phase of the open sea convection from december 2011 to mid february 2012 currents 1 10 cm s 1 suspended sediment concentrations

ancient coastal wells of caesarea maritima israel an indicator for relative sea level changes during the last 2000 years abstract during the detailed excavations of ancient caesarea israel east mediterranean 64 coastal water wells have been examined that date from the early roman period with the oldest occurring in the 1st century ad up to the end of the crusader period mid 13th century ad the depths of these coastal water wells establish the position of the ancient water table and therefore the position of sea level for the first century ad up to 1300 ad the connection between the coastal water table and changes in sea level has been established from modern observations in several wells on time scales of days and months and this is used to reconstruct sea level during historical time the results indicate that during the byzantine period sea level at caesarea was higher by about 30 cm than today the late moslem and crusader data shows greater fluctuations but the data sets are also much smaller than for the earlier periods the consistency of the data indicates that the near coastal well data from caesarea provides a reliable indicator of sea level change with an accuracy of about 10 15 cm these results are consistent with observations for earlier periods and with comparisons to model predicted glacio hydro isostatic sea level change indicate that ocean volumes have been constant for much of the past 2000 years the well data is also consistent with an absence of significant vertical tectonic movement of the coast at caesarea over about 2000 years

longshore sand transport estimates along the mediterranean coast of israel in the holocene abstract the nile littoral cell one of the world s longest runs 650 km along the southeastern mediterranean from abu quir bay near alexandria egypt to haifa bay on the northern israeli coast haifa bay constitutes the northernmost final depositional sink of nile derived quartz sand transported from the nile delta by longshore currents generated by approaching breaking waves the northward net sand transport along the mediterranean coast of israel results from larger waves approaching from west south west and south west compared to their counterparts from west north west and north west this study utilizes an extensive new database gathered from sediment drill cores marine geophysical maps and field observations to measure the volume of sand deposited in haifa bay and the adjacent zevulun plain during the holocene it then compares this volume to recent data including measurements of sand accumulation along haifa port s main breakwater constructed in the southern entrance of the bay as well as longshore sand transport estimates along the northern carmel coast research findings estimate the annual average quantity of sand transported to haifa bay throughout the period at 80 000 90 000 m3 the findings further conclude that this amount has not changed appreciably over the past 75 years evaluating calculated values over the long term it is suggested that the characteristics of longshore sand transport along the coast of israel have not changed significantly during the past 7900 8500 years it is obvious that this conjecture should be treated with reservations

reconstructing saharan dust transport to the eastern mediterranean sea during the last 180 ka using endmember modelling of grain size data endmember modelling on the terrigenous silt fraction of nine marine sediment cores spanning up to 180 000 years reveals the influx of north african dust into the eastern mediterranean sea the dust grain size modes decrease with transport distance from 50 m off the african coast to ca 30 m in the aegean sea the dust signal is strongly influenced by hydrological changes in northern africa changes from arid to humid periods are documented in the grain size data of all cores the climatic signal gets weaker with growing distance from the source and close to large fluvial sediment sources such as the nile frequency and wavelet analyses show a strong orbital precession signal that is known to trigger the migration of the monsoonal rain belt in northern africa the influence of climate changes on suborbital time scales on dust influx is less distinct but dansgaard oeschger interstadials and heinrich like events are documented in some cores in the sediment core closest to the source three endmembers represent one or more dust sources in northern africa with growing distance from the source the three modes cannot be separated anymore and appear as one multimodal dust endmember

sea level change along the french mediterranean coast for the past 30 000 years abstract observational evidence for sea level change along the french mediterranean coast has been examined and compared with glacio hydro isostatic models to predict the spatial and temporal patterns of change for about the past 30 000 14c years these predictions are pertinent to discussions of changing ocean volumes during this interval the tectonic stability or otherwise of the coastal areas mantle rheology and the timing of possible human occupation of the now submerged coastal plain and caves such as cosquer cave near marseille the principal results from the analysis are i sea levels along this section of the coast have risen continually since the time of the last glacial maximum lgm and at no time during the holocene has the mean sea level been higher than that of today ii the coast has been tectonically stable between marseille and nice as well as further to the west in roussillon western corsica may have experienced a slow tectonic uplift of between 0 15 0 3 mm year for the past 3000 years but northernmost corsica appears to have been stable during this same interval iii during the lgm sea levels along the coast and immediate off shore areas stood at between 105 115 m below present level the range reflecting the importance of the isostatic contributions during oxygen isotope stage 3 sea levels do not appear to have risen locally above about 60 m iv the rebound parameters describing the mantle rheology and ice sheets required to match the limited observational evidence are consistent with the results of similar analyses carried out for other parts of europe because of its distance from the former northern ice sheets the isostatic factors are particularly sensitive to the value of the lower mantle viscosity v the model predictions for sea level change at the cosquer cave site and for its immediate environments indicate that the cave was last readily accessible before about 10 700 500 14c years about 12 500 500 cal years bp and that the cave entrance was completely flooded by 9000 200 radiocarbon years bp between about 9800 and 10 300 calibrated years bp the cave was above sea level throughout the oxygen isotope stage 3

compressional velocity structure and anisotropy in the uppermost mantle beneath italy and surrounding regions travel times of about 39 000 pn arrivals recorded from regional earthquakes by the italian telemetered seismic network and by stations of nearby countries are inverted to image lateral variations of seismic velocity and anisotropy at subcrustal depth in italy and surrounding regions this method allows simultaneous imaging of variations of pn velocity and anisotropy as well as crustal thickness variations the po plain the adriatic sea and the ionian sea have normal to high pn velocities in contrast lower velocities 7 9 8 0 kin s are imaged in italy beneath the western alps the northern apennines and eastern sicily and nearby calabria as well as in northern albania and beneath the pannonian basin low pn velocities beneath the northern apennines correlate with present day extension and may have resulted from thermal anomalies in the uppermost mantle possibly due to delamination processes low velocities are consistent with the high attenuation zone inferred in the uppermost mantle beneath the internal apennine units and the tyrrhenian margin of the peninsula by mele et al 1996 1997 on the contrary low velocities beneath the western alps may be an apparent effect due to the abrupt thickening of the crustal roots pn velocity is anisotropic in the study area with a maximum amplitude of 0 2 km s the largest anisotropic velocity anomalies are observed along the major arc structures of italy i e the northern apennines and the calabrian arc indicating that these features are controlled by uppermost mantle processes the anisotropy anomaly along the calabrian arc extends as far as albania but ends abruptly north of this area suggesting that a lithospheric discontinuity is present along the northern albanian border

the relationship of low frequency deep variability near the hebble site to gulf stream fluctuations abstract current meter measurements from two recent moored array experiments on the continental rise and in the gulf stream south of nova scotia are examined to determine horizontal and vertical structures of energetic time variable motions the intent being to put the so called abyssal storms observed at the hebble site into the context of the larger scale energetics of the region empirical orthogonal functions are used to examine characteristics of the motions as a function of frequency one array spanned the continental rise and the stream in many low frequency bands motions exhibit properties of nearly barotropic topographic rossby waves and are coherent over the array phase propagation of the waves is to the southwest indicating onshore energy propagation data from a second current meter array within the stream are examined to determine source region structure and relationship to rise variability in most frequency bands stream motions are too complex to be clearly separable into empirical modes but a significant mode does exist in the band centered at 30 days westward propagation is observed in the meridional component of the velocity at 4000 m depth and the associated zonal wavenumber matches that observed on the rise the hypothesis that westward propagating meanders can directly excite far field motions is explored and found to be consistent with observations in the 30 day band

heat flow and depth versus age for the mesozoic northwest atlantic ocean results from the sohm abyssal plain and implications for the bermuda rise abstract heat flow in the sohm abyssal plain is measured to be 53 mw m 2 at an age of 163 ma this is 25 higher than predicted by conductive cooling models even though the sediment corrected basement depth of 6 5 km at this location is normal for its age an analysis of existing heat flow depth and geoid anomalies in the northwest atlantic shows that there is little correlation between heat flow and depth throughout the entire region depth and geoid are clearly related to the bermuda swell while the associated heat flow anomaly once adjusted for variations with age is limited to 5 mw m 2 and only decays to the south this means that the bermuda swell is probably not caused by extensive thermal reheating within the lithosphere but instead by dynamic uplift at its lower boundary due to the convective upwelling of a mantle plume the regionally high heat flow in the northwest atlantic may be a thermal remanent of previous plumes which passed beneath this region early in its history therefore depth and heat flow anomalies from this region cannot be used to provide constraints on steady state parameters of the lithosphere such as the presence or absence of a long term boundary layer at its base

sediment dispersal along northern israel coast during the early holocene geological and archaeological evidence abstract combined geological and archaeological study of finds at atlit yam a pre pottery neolithic settlement submerged off the carmel coast of northern israel provides new information on sediment provenance and dispersal in the southern levant clay mineral analyses of mud rich samples collected in a water well ca 8100 7550 yrs b p at this site are useful for determining the early holocene circulation pattern along this margin analyses record the predominance of fluvial sediment from proximal carmel highland sources to the east as indicated by illite and of marine sediment from the north and northeast as indicated by kaolinite this north to south coastal transport is in marked contrast to the present south to north dispersal pattern where smectite rich nile material is derived from distal sources and carried hundreds of kilometers to the carmel margin the interpreted coastal circulation pattern indicates that although the modern nile delta major source of sediment in the eastern mediterranean had begun to form about 8000 7500 yrs ago it had not yet begun to supply substantial amounts of sediment to as far north as the carmel coast by the time the water well was abandoned the atlit yam site serves as a unique geochronologic gauge valuable for interpreting climatic oceanographic and sedimentologic conditions in the se mediterranean which as recently as 7500 yrs ago were markedly different than those prevailing at present

holocene sea level changes based on submerged archaeological sites off the northern carmel coast in israel abstract a series of submerged archaeological sites found on the continental shelf between haifa and atlit indicate a continuous marine transgression between 8000 and 1500 yr b p the sites are embedded in the upper part of a marshy clay that fills the trough between the coastal aeolianite kurkar ridge and a ridge now submerged some 1000 to 1500 m to the west the submerged prehistoric sites belong to two main chronological units prepottery neolithic b 8000 yr b p and late neolithic ca 6500 yr b p these were found at depths of 12 to 8 m and 5 to 0 m respectively bronze age and byzantine anchors were found at depths of 5 to 3 m and 4 to 1 8 m respectively as the archaeological materials are firmly dated we can reconstruct the rate of marine transgression from 8000 yr b p to the present and the eastward movement of settlements through time as related to the transgression

characterization of deep sea storms abstract to describe and quantify the physical forcing of sediment transport events at the hebble site velocity stress and sediment concentration data were obtained during a year long deployment through the year a variety of intense sediment transporting events were recorded careful analysis of these events reveals that only a small proportion of the peaks in suspended sediment concentration correspond to local erosion most sediment events were clouds of fine suspended material advected into the region analysis of progressive vector diagrams reveal that these advected clouds were bounded by regions with concentration gradients as high as 200 g 1 1 km 1 the high gradients suggest streams of sediment bearing water with sharp fronts of sediment concentration along their sidewalls were veering across the region the largest concentrations of suspended sediment were observed during local suspension events the growth and decay of the sediment clouds during the local events did not exactly track the boundary shear stress rapid erosion occurred as the stress exceeded a critical shear stress maximum suspended concentrations occurred shortly after erosion began indicating a source limited erosion process the depositional period lasted for several weeks whereas the erosion occurred in only a few days photographs of the bottom reveal depositional features crag and tail dunes which are aligned with the post storm flow not the erosional flow direction

absorption of internal waves by the benthic boundary layer abstract the interaction of near inertial velocities with the benthic boundary layer above a flat bottom is investigated using a diagnostic model and a 3 month time series of velocity from a fixed array of current meters the observed near inertial motions are assumed to be due to internal waves and diurnal tides if the vertical wavelength of the internal waves is much larger than the boundary layer thickness the turbulent stresses acting on the near inertial motions and the work done by the stresses on these motions can be computed the boundary layer is estimated to absorb 0 003 to 0 024 erg cm 2 s 1 from the near inertial motions with one third coming from the k1 diurnal tide and the rest from the internal wave field this is far less than estimated by leaman 1976 and suggests that the benthic boundary layer on a flat bottom plays a minor role in dissipating internal wave energy this is also much less than the total energy dissipation in the boundary layer suggesting that the boundary layer is

control of alongshore oriented sand spits on the dynamics of a wave dominated coastal system holocene deposits northern gulf of lions france article the maguelone shore extends along the northern coast of the gulf of lions west of the rhone delta and east of high gradient coastal streams that have provided most of the clastic sediments to the gulf of lions margin since the early miocene this 10 km wide area is constituted by a small coastal watershed 15 km long in low lying carbonate hills a kilometre wide marsh a sandy beach barrier and a shoreface experiencing local low sedimentation rates this onshore offshore transition zone is a key area to understand the relationships between erosion by pass deposition and preservation processes unlike the neighbouring rhone deposits that display numerous thick deltaic sequences related to a continuous sediment flux the maguelone shore exhibits peculiar sedimentary bodies the analysis of about 250 km of new vhr seismic profiles acquired over the study area 9 short cores and outcrops data allowed us to determine the three dimensional high resolution geometry of the coastal system tracts from quaternary to present day this revealed dominant denudation processes in the upstream catchments associated with the formation of incised valleys during quaternary lowstands in addition this study investigates the erosion and deposition mechanisms controlled by littoral hydrodynamics that have been taken place on this shore since the last transgression in particular metre high and hundreds of metre long sandy bodies constructed by alongshore hydrodynamics were identified and their effect on the morphodynamics of the whole littoral system is discussed the maguelone shore can be used as an experimental study for onshore offshore dynamics under the influence of microtidal wave current hydrodynamics and very low river derived sediment flux during a eustatic cycle geometry of system tracts across flood plain to shoreface is usually considered to be controlled by relative sea level changes and is successfully analysed with 2d sequence stratigraphy cross shore models it is observed that in areas like the maguelone shore traditional sequence stratigraphy methods might not be fully relevant and need to integrate alongshore hydrodynamical processes

late quaternary stratigraphy and paleogeography of the eastern nile delta egypt abstract a petrological study of numerous sediment borings identifies the late pleistocene and holocene lithofacies in the northeastern nile delta of egypt a coarsening upward sequence characterizes the major holocene depocenters located along the northern margin of the present delta stratigraphic correlation of radiocarbon dated sections and mapping of key facies such as delta front mud reveal the locations of four major holocene delta lobes related to former distributary branches of the nile river mendesian pelusiac tanitic and pre modern damietta these lobes formed primarily of marine prodelta and delta front deposits interfinger geographically but radiocarbon dating indicates that their bases are not synchronous lobes developed for the most part since 8000 years b p i e as the rate of eustatic sea level rise began to decrease climatic and sediment discharge fluctuations lateral migrations of distributaries and isostatic subsidence of land are additional factors that affected the temporal and spatial distributions of the lobes paleogeographic maps reveal the changes with time in the distributions of different lobes and deltaic plain environments marsh lagoons and concomitant displacement of the coastline holocene sediment accumulation rates to 500 cm per 1000 years are calculated this is 10 times greater than that on the nile cone and 50 times greater than on the egyptian continental shelf the delta coastal margin in the study area migrated northward by as much as 50 km during the past 5000 years an average progradational rate of up to 10 m per year the general configuration of the present delta developed during the past millennium the major changes recently induced by man in this region coupled with a series of continuing natural phenomena slow rise in sea level coastal erosion subsidence have markedly affected the evolution of the delta petrological study of the nile delta sediments provides baseline reference information to help recognize changes in the recent geological past to help identify those taking place at present and possibly to help predict those likely to occur in this region in the future

a description of the bottom boundary layer at the hebble site low frequency forcing bottom stress and temperature structure abstract a preliminary description of the bottom flow at the hebble site 4800 m is presented based on bottom tripod measurements in the lower 5 m of the bottom mixed layer extending to within 30 cm of the seabed and thermistor measurements extending through the mixed layer up to 110 m two different deployment periods are described covering approximately 4 days in april of 1983 and 80 days from june to september 1983 the near bottom flow during the 80 day period is composed of low frequency motions with fluctuations of 20 days or greater with less energetic fluctuations of tidal and inertial periods riding on the flow the speed at 1 m during the long deployment varies from 0 to 17 cm s 1 suggesting that the boundary layer depth should also be modulated at low frequency direct reynolds stress estimates during times of moderate flow indicate the local boundary layer height is reasonably estimated using a simple drag law and classical scaling u f the mixed layer depths observed at the site are 30 70 m corresponding to boundary layer thicknesses estimated for the strongest flows observed and are typically more than five times the estimated boundary layer thickness for moderate flows two flow events observed during the 80 day record correspond to weak and moderate benthic storms during which significant sediment resuspension occurs one event has eastward flow and the other westward the potential importance of the role of superposition of fluid motions of several frequencies in determining the magnitude of such storms is demonstrated by comparing these two events

origin of the sinai negev erg egypt and israel mineralogical and geochemical evidence for the importance of the nile and sea level history abstract the sinai negev erg occupies an area of 13 000 km 2 in the deserts of egypt and israel aeolian sand of this erg has been proposed to be derived from the nile delta but empirical data supporting this view are lacking an alternative source sediment is sand from the large wadi el arish drainage system in central and northern sinai mineralogy of the negev and sinai dunes shows that they are high in quartz with much smaller amounts of k feldspar and plagioclase both nile delta sands and sinai wadi sands upstream of the dunes also have high amounts of quartz relative to k feldspar and plagioclase however sinai wadi sands have abundant calcite whereas nile delta sands have little or no calcite overall the mineralogical data suggest that the dunes are derived dominantly from the nile delta with sinai wadi sands being a minor contributor geochemical data that proxy for both the light mineral fraction sio 2 10 al 2 o 3 na 2 o k 2 o cao and heavy mineral fraction fe 2 o 3 mgo tio 2 also indicate a dominant nile delta source for the dunes thus we report here the first empirical evidence that the sinai negev dunes are derived dominantly from the nile delta linkage of the sinai negev erg to the nile delta as a source is consistent with the distribution of osl ages of negev dunes in recent studies stratigraphic studies show that during the last glacial period when dune incursions in the sinai negev erg began what is now the nile delta area was characterized by a broad sandy minimally vegetated plain with seasonally dry anastomosing channels such conditions were ideal for providing a ready source of sand for aeolian transport under what were probably much stronger glacial age winds with the post glacial rise in sea level the nile river began to aggrade post glacial sedimentation has been dominated by fine grained silts and clays thus sea level along with favorable climatic conditions emerges as a major influence on the timing of dune activity in the sinai negev erg through its control on the supply of sand from the nile delta the mineralogy of the sinai negev dunes is also consistent with a proposed hypothesis that these sediments are an important source of loess in israel

the interplay between relative sea level rise and sediment supply at the distal part of the nile littoral cell during holocene sea level rise coastal areas became transitional environments as marine incursion covered the land changing conditions resulted in dynamic depositional environments that recorded the migration and stabilization of modern shorelines these processes are viewed in the zevulun plain haifa bay israel record located in the northern edge of the nile littoral cell sedimentological and palaeontological analyses combined with dating enabled the reconstruction of the holocene chrono stratigraphical frame the results reveal an unconformity representing a long period of exposure and erosion during the last glacial the interplay between relative sea level rise and sediment supply was first set out by the deposition of alluvial sediments evidence of the hydrological system reactivation and base level landward migration sea flooding of the zevulun plain started about 7 8 cal ka bp and the coastline was pushed eastward nile driven sands transported by longshore currents formed dunes that blocke

morphology and dynamic sedimentology of the eastern nile delta shelf coleman j m roberts h h murray s p and salama m 1981 morphology and dynamic sedimentology of the eastern nile delta shelf mar geol 42 301 326 some 13 000 km of bathymetry and overlapping side scan sonar data were collected over a 4450 km2 area of the eastern nile river shelf these data coupled with more detailed surveys of selected areas including bottom sampling and current measurements contribute to the understanding of shelf morphology lithofacies relationships and sediment transport processes four morphologic zones were defined zone 1 smooth bottomed flocculated clays and silty clays extending from the shore line 40 km seaward to the 25 m contour zone 2 a sand belt 5 20 km wide extending eastward from the damietta mouth and curving toward the coast at the boundary of the study area dominant bottom features were migratory bedforms of various dimensions superimposed on linear sand ridges zone 3 smooth clay to silty clay bottom topography punctuated with distinct algal mounds the mounds up to 10 m relief are composed of living coralline algae which contribute coarse debris to the surrounding sediments zone 4 mud diapirs and shelf edge slumps characterize this distal part of the shelf and the upper slope sand on the inner shelf is actively migrating and probably does not represent a relict deposit the damietta distributary causes a large scale perturbation in the mean easterly drift along the egyptian coast unusually strong currents capable of transporting and reworking large volumes of sand are associated with an eddy trapped behind this feature the directionality of these currents and the curvature of the eddy axis correspond well to the distribution pattern of sand on the inner shelf

the effect of ductile lithic sand grains and quartz cement on porosity and permeability in oligocene and lower miocene clastics south china sea prediction of reservoir quality ductile clay rich sand grains control porosity and permeability in the fluvio deltaic oligocene and lower miocene sandstones of the south china sea ductile grains account for between approximately 5 and 50 of the original sand grain population there is a pronounced loss of porosity with increasing burial depth in the basin at depths of less than 3000 m this is due solely to ductile grain compaction where the rate of porosity loss with depth increases with increasing ductile grain content at depths greater than 3000 m the steep porosity loss with depth is due to combined ductile grain compaction and quartz cementation the amount of quartz cement increases with increasing burial depth however cleaner sandstones tend to have greater amounts of quartz cement at any given depth below 3000 m this leads to convergence of porosity evolution for the clean and ductile rich sandstones below 3000 m there is a rapid loss of permeability with decreasing porosity because compaction of ductile grains smears them between rigid quartzose grains leading to blocked pore throats a consequence of this process is that the lowest permeabilities are found in sandstones with the highest ductile grain contents quartz cement does not have a clear and discernible control on permeability the pronounced loss of porosity with increasing depth and permeability with decreasing porosity leads to low permeability at relatively shallow burial depths reservoir quality is thus controlled by the nature of the primary sand and depth of burial the sediment supply system led to systematic changes in ductile grain content across the basin with ductile content increasing into the more distal part of the sediment system the consequence is that depth of economic basement in terms of porosity or permeability can be predicted as a function of ductile grain content and burial depth for prospects across the basin

apparent roughness in wave current flow implication for coastal studies high turbulence intensities generated by waves in the wave bottom boundary layer affect the mean current velocity and should be taken into account for calculation of currents in the presence of waves this influence of the wave induced turbulence on the mean current can be schematized by introducing an apparent bed roughness which is larger than the physical bottom roughness apparent bed roughness is defined here as roughness that provides the same depth mean velocity for current alone configuration as for the wave current flow a one dimensional vertical k l turbulence closure model that allows detailed time dependent flow modeling has been applied for apparent roughness computations the domain of variable parameters is chosen according to the israeli near shore conditions an approximate expression for apparent bed roughness calculations as a function of wave and current parameters based on this turbulence closure model is derived simulation of flow patterns on the tel aviv coast using the three

global comparison of benthic nepheloid layers based on 52 years of nephelometer and transmissometer measurements abstract global maps of maximum bottom particle concentration benthic nepheloid layer thickness and integrated particle mass in benthic nepheloid layers bnl based on 2412 global profiles collected using the lamont thorndike nephelometer from 1964 to 1984 are compared with maps of those same properties compiled from 6392 global profiles measured by transmissometers from 1979 to 2016 outputs from both instruments were converted to particulate matter concentration pm the purposes of this paper are to compare global differences and similarities in the location and intensity of bnls measured with these two independent instruments over slightly overlapping decadal time periods to combine the data sets in order to expand the time scale of global in situ measurements of bnls and to gain insight about the factors creating sustaining bnls the similarity between general locations of high and low particle concentration bnls during the two time periods indicates that the driving forces of erosion and resuspension of bottom sediments are spatially persistent during recent decadal time spans though in areas of strong bnls intensity is highly episodic topography and well developed current systems play a role these maps will help to understand deep ocean sediment dynamics linkage with upper ocean dynamics the potential for scavenging of adsorption prone elements near the seafloor and provide a comprehensive comparison of these data sets on a global scale during both time periods bnls are weak or absent in most of the pacific indian and atlantic basins away from continental margins high surface eddy kinetic energy is associated with the kuroshio current east of japan both data sets show weak bnls south of the kuroshio but no transmissometer data have been collected beneath the kuroshio itself sparse nephelometer data show moderate bnls just north of the kuroshio extension but with much lower concentrations than beneath the gulf stream strong bnls are found in areas where eddy kinetic energy in overlying waters mean kinetic energy near bottom and energy dissipation within the bottom boundary layer are high areas of strongest bnls include the western north atlantic argentine basin south atlantic areas around south africa tied to the agulhas current region and somewhat random locations in the antarctic circumpolar current of the southern ocean

a multi proxy shallow marine record for mid to late holocene climate variability thera eruptions and cultural change in the eastern mediterranean abstract the river nile catchment is considered the major source of nutrient rich freshwater and sediment draining into the eastern mediterranean sea thus exceptional high resolution record from the nile littoral cell likely traces changes in the nile outflows related to climatic changes driven by the monsoonal system this study used multi proxy analyses combining sedimentological geochemical and organic stable isotope data along with foraminiferal data in a southeastern levantine inner shelf sedimentary sequence to understand mid to late holocene northeast african climate variability the palynological record is used to reconstruct local scale changes in the regional vegetation related to the mediterranean climate system the analyzed records reveal multi decadal to centennial pacing of paleoceanographic and paleoclimatic changes with most prominent events recorded at 4 28 3 6 and at 2 9 kyr bp these transitional periods characterized by simultaneous high 15n values and low total organic carbon toc suggest drier climatic conditions decrease in nile discharge leading to lower nutrient supply a stable and arid climate during mid late holocene 4 5 3 6 cal kyr bp associated with a weaker monsoon system as well as with a weaker mediterranean climate system is indicated based on high and constant sedimentation rates 400 cm kyr 1 along with relatively stable values and only occasional weak fluctuations documented in all of the proxies this climatic pattern is punctuated by a peak in maximum aridity at 4 28 kyr bp evidenced by low toc value and low arboreal pollen ap and artemisia chenopodiaceae a c pollen ratios and the sharp decline in the abundance of benthic foraminifera cribroelphidium poeyanum and valvulineria bradyana this change corresponds with the well studied 4 2 kyr bp drought event in the middle east mesopotamia and south asia during the late holocene 3 6 2 8 cal kyr bp the climate became unstable characterized by shifts between relatively wetter and drier conditions as evident in considerable fluctuations in all proxies maximum positive excursions of toc values c n ratio along with high dominance of opportunistic foraminiferal species e g ammonia tepida indicate northeast african wetter conditions and increased nile discharge at 3 5 3 3 3 2 and 3 0 kyr bp the distinct and abrupt transition from a stable to an unstable climate regime around 3 6 kyr bp may have been influenced by the thera volcanic eruption thus the sedimentary record investigated in this study may provide evidence for the impacts of this well known volcanic eruption not just on the climate regime in the levant but also on the ancient near east and egypt

global assessment of benthic nepheloid layers and linkage with upper ocean dynamics abstract global maps of the maximum bottom concentration thickness and integrated particle mass in benthic nepheloid layers are published here to support collaborations to understand deep ocean sediment dynamics linkage with upper ocean dynamics and assessing the potential for scavenging of adsorption prone elements near the deep ocean seafloor mapping the intensity of benthic particle concentrations from natural oceanic processes also provides a baseline that will aid in quantifying the industrial impact of current and future deep sea mining benthic nepheloid layers have been mapped using 6 392 full depth profiles made during 64 cruises using our transmissometers mounted on ctds in multiple national international programs including woce save jgofs clivar repeat hydrography and go ship during the last four decades intense benthic nepheloid layers are found in areas where eddy kinetic energy in overlying waters mean kinetic energy 50 m above bottom mab and energy dissipation in the bottom boundary layer are near the highest values in the ocean areas of intense benthic nepheloid layers include the western north atlantic argentine basin in the south atlantic parts of the southern ocean and areas around south africa benthic nepheloid layers are weak or absent in most of the pacific indian and atlantic basins away from continental margins high surface eddy kinetic energy is associated with the kuroshio current east of japan data south of the kuroshio show weak nepheloid layers but no transmissometer data exist beneath the kuroshio a deficiency that should be remedied to increase understanding of eddy dynamics in un sampled and under sampled oceanic areas

late holocene dune mobilizations in the northwestern negev dunefield israel a response to combined anthropogenic activity and short term intensified windiness abstract the study of the effects of past climates on ancient cultures is usually based on geologic records pertaining to rainfall and temperature fluctuations and shifts this study proposes a paradigm of anthropogenic activity and windiness fluctuations to explain aeolian sedimentation and dune mobilization in the northwestern nw negev desert dunefield israel the proposed paradigm contributes a different approach to estimating the effect of climate changes on the unprecedented agricultural and urban settlement expansion during the late roman to early islamic period in the northern and central negev desert this study builds upon the late holocene cluster of luminescence ages coupled with analysis of archaeological finds and historical texts whereas the nw negev dunefield was generally stable during the holocene intermittent dune mobilization during the late holocene at 1 8 ka and mostly 1 4 1 1 ka 600 900 ce are linked to periods of human occupation the idea that the last glacial dune encroachments alone that formed the nw negev dunefield is connected to cold event windy climates that may have intensified east mediterranean cyclonic winter storms cannot explain the late holocene dune mobilizations a conceptual model indicates a connection between late holocene dune mobilization widespread anthropogenic occupation and activity and windiness historic grazing and uprooting shrubs for fuel in the past by nomads and sedentary populations led to decimation of dune stabilizers biogenic soil crusts and vegetation causing dune erodibility and low grade activity short term events of amplified wind power in conjunction with periods of augmented anthropogenic activity that triggered major events of dune mobilization elongation and accretion have been preserved in the dune chronostratigraphy because they were short lived the dune mobilization events corresponding windiness and probable dustiness which were examined affected the northern negev landscape differentially however they cannot be shown to have affected the environment sufficiently to influence the decline of the late byzantine and early islam agricultural establishment this study demonstrates the sensitivity of dunes in arid and semi arid regions to a combination of local and short term fluctuations in windiness at times of widespread grazing anthropogenic activity the results indicate that in similar future scenarios sand mobilization may be similarly retriggered to varying degrees

composition of clays along the continental shelf off israel contribution of the nile versus local sources the eastern mediterranean sedimentary regime is dominated by sediment transport from the nile river and its delta but recent studies have also suggested a certain contribution of clay fraction from streams to the continental shelf and slope off israel in the present study we focused on clay fraction deposition along the inner 40 1000 m water depth shelf of israel in order to substantiate and quantify its different sources for this purpose detailed xrd mineralogical determinations as well as chemical compositions of the clay 2 m fraction of marine and continental sediments were used the clay mineral composition of israeli stream sediments is variable with no distinct spatial or temporal trend but within a limited assemblage this clay assemblage is made up of illite smectite is phases 70 90 kaolinite 5 25 and illite 10 and is similar to that of the nile however it is clearly distinguished by the type of the is phases which are derived mainly from mesozoic outcrops and recent sediments soils and are less expandable than those of the nile which are derived mainly from weathered basalt the nile derived component is depleted in the marine clay fraction along the israel coast evidenced by a decrease of is expandability and the fe2o3 al2o3 ratio and an increase in the k2o al2o3 mgo al2o3 and cao al2o3 ratios the depletion is well pronounced north of tel aviv where the largest coastal plain stream flows to the sea a northward increase of carbonates in the clay fraction and particularly of the bioskeletal component is indicated by the ratios of mgo and sr to cao the contribution of the local streams to the shallow shelf marine clay fraction is estimated to be about 50 a minor contribution of desert dust is identified by the relative increase in kaolinite in the marine sediments south of tel aviv

calibration of the c 14 timescale over the past 30 000 years using mass spectrometric u th ages from barbados corals uranium thorium ages obtained by mass spectrometry from corals raised off the island of barbados confirm the high precision of this technique over at least the past 30 000 years comparison of the u th ages with 14c ages obtained on the holocene samples shows that the u th ages are accurate because they accord with the dendrochronological calibration before 9 000 yr bp the 14c ages are systematically younger than the u th ages with a maximum difference of 3 500 yr at 20 000 yrbp the u th technique thus provides a way of calibrating the radiocarbon timescale beyond the range of dendrochronological calibration

reevaluating the tectonic uplift of western mount carmel israel since the middle pleistocene abstract reevaluation of geological and archaeological evidence from western mount carmel constrains its maximal tectonic uplift since the middle pleistocene tabun cave presently 45 m above sea level asl revealed human occupation from about 600 ka to 90 ka before present the 25 m thick archaeological strata at tabun are composed of laminated fine sand silt and clays moreover no marine deposits were found in tabun or nearby caves since sea level in the last 600 ka reached a maximal of 5 to 10 m asl tabun cave could not have been uplifted since then by more than 35 to 40 m that is a maximal average rate of 58 to 67 mm ka

excepftonally strong near bottom flows on the continental rise of nova scotia recent current velocity measurements across the lower continental rise of nova scotia show a deep equatorwardflow with speeds maximum 73 centimeters per second among the highest recorded for the deep sea silicate measurements indicate that this flow usually consists of southern source antarctic bottom water these measurements confirm the existence of a second and deeper western boundary flow that was earlier inferredfrom geological observations

molluscan live and dead assemblages in an anthropogenically stressed shallow shelf levantine margin of israel abstract mismatches between live and dead molluscan assemblages associated with recent rapid anthropogenic changes can be used to track these changes the eastern mediterranean is naturally oligotrophic but recent urbanization of the israeli coastal plain has enriched the littoral environment by injection of large amounts of treated wastewater onto the shelf the largest point source is the dan region wastewater project shafdan taxonomy and species rank order of abundance of modern sediment top death assemblages were compared to live collected mollusk assemblages from two clean control stations pl29 pl64 and a polluted site pl3 near the shafdan sewage sludge outlet at 36 m water depth seasonal variability was captured by dredge and box core sampling in winter january spring may summer july and fall november of 2012 over 11 000 individuals of bivalves and gastropods were collected and analyzed diversity indices and nmds and cluster analysis showed significant differences between live and dead assemblages from all stations and seasons however the rank order of the abundant live and dead species remained similar at each sampling station resulting in high live dead agreement of jaccard chao index and spearman s rho similarity coefficient live dead agreement of molluscan assemblages was preserved in the shafdan area by the naturally high abundance of species that are tolerant to pollution and by the annual dispersion of the sludge by winter storms which prevent development of long term anoxia moreover the high frequency of storms in the winter of 2012 prevented a substantial amount of sludge from accumulating on the seafloor explaining the similarity between the live assemblages of the polluted and the control sampling sites live dead agreement is a test that is too conservative to track the impact of the shafdan sludge on the macrobenthic fauna in the israeli shelf other tests especially the increase in the abundance of deposit feeding pollution tolerant species in the live assemblage show that there is an ongoing impact of the sludge on the benthic community

benthic foraminifera as palaeoenvironmental indicators during the last million years in the eastern mediterranean inner shelf abstract benthic and planktonic foraminifera were studied in inner shelf sedimentary sequences in haifa bay israel three boreholes taken at water depths from 5 to 14 m spanning about the last 1 ma and a set of modern sediment samples used as modern analogue were utilized for reconstructing palaeoenvironments and palaeobathymetry the palaeoenvironmental data were used for assessing tectonic activity of the carmel fault a branch of the dead sea transform that bounds the southern side of the bay quantitative analyses showed four biofacies a fresh to brackish wetland environment and three progressively deepening marine biofacies relative water depth ranges were estimated using changes in benthic foraminiferal assemblages presence or absence of ammonia sp 1 and the percentage of planktonic foraminifera the distribution of the biofacies suggests water depths no deeper than 15 m during most interglacial stages water depths to 15 40 m during short transgressive phases of mis 5 5 7 11 and 13 and water depth reaching 40 80 m in the earliest transgressive phases mis 27 and mis 29 the environmental conditions on both sides of the fault were quite similar along the succession this suggests that the movements of the uplifted and down faulted blocks have more or less coincided since about 1 ma

holocene era submerged notches along the southern levantine coastline punctuated sea level rise abstract the study presented here reports on erosional notches pits and potholes observed at present sea level and submerged at a series of sites along the southern levantine coastline for such submerged features to be formed and preserved there must be a period of relative sea level stagnation followed by drowning this process can occur in response to sea level change tectonic or isostatic offsets the specific coastline hosting these features is not considered tectonically or isostatically affected and therefore for much of the mediterranean is viewed as a eustatic sea level reference point while similar features have been observed elsewhere in the eastern mediterranean confining their ages has been difficult due to the much older ages of the host rocks in many cases encompassing multiple glacial cycles here for the first time they are located in relatively young host rock

holocene evolution of the haifa bay area israel and its influence on ancient tell settlements the geographical evolution of haifa bay and zevulun plain israel from the late pleistocene to the holocene is based on detailed analysis of drilled cores at the beginning of the holocene the bay area was still under terrestrial conditions only about 9500 to 9000 cal yr bp when sea level rose to about 35 30 m below present sea level b s l did nile derived sand start to bypass the carmel headland and haifa bay come into existence as a morphological feature between 8000 and 7150 cal yr bp when sea level was 14 10 m b s l the invading sea crossed the present day coastline at about 6800 to 6600 cal yr bp sea level rose to about 5 m b s l and flooded the zevulun plain up to 2 km inland and the river qishon estuary up to 4 km inland it is still unknown exactly when the sea reached its maximum penetration inland but later about 4000 years ago the coastline in the research area was still east of the present day coast up to 3 km in the zevulun plain and 4 8 km in the river qishon estuary when the coastline started to retreat westward the reclamation was followed by intensive deposition of shallow marine sand and aeolian dunes while to the east different wetland conditions developed the archaeological data indicate that during the early bronze age i and early bronze age ii dated to between 5600 and 4700 cal yr bp and even later during the middle bronze age ii period about 4600 to 3500 cal yr bp the coastline was still east of the present day coast but it never actually reached the bases of most of the tells as has been suggested except for tel akko and tel abu hawam

the origin and disappearance of the late pleistocene early holocene short lived coastal wetlands along the carmel coast israel abstract the formation of short lived backswamps along the carmel coast of israel coincides with the rapid global sea level rise during the late pleistocene early holocene transition the current study shows that the wetland phenomena originated around 10 000 yr ago and dried up shortly before the local pre pottery neolithic humans settled on the wetland dark clay sediments 9430 cal yr bp palaeontological and stable isotope data were used in this study to elucidate previously published sedimentological reconstruction obtained from a core drilled into the western trough of the carmel coastal plain the water body contained typical brackish calcareous fauna with variable numerical abundance and low species richness of ostracods and foraminifera the 18o and 13c of the ostracod cyprideis torosa show close similarity to the present pleistocene coastal aquifer isotopic values this study therefore concludes that the wetlands were shallow water bodies fed by groundwater with no evidence of sea water mixing it seems that they developed as the result of high groundwater levels transportation of sediments landward and deposition of sand bars at the paleo river mouths it is still not fully understood why these wetlands deteriorated abruptly and disappeared within less than 1000 yr

sediment concentration profiling in hebble using a 1 mhz acoustic backscatter system abstract as part of the high energy benthic boundary layer experiment hebble a 1 mhz acoustic backscatter system abss was deployed in 4800 m of water on the nova scotian continental rise the purpose of the instrument was to measure non intrusively a time series of the vertical concentration profile over the course of one year from september 1985 to september 1986 in this paper we discuss the details of the abss instrument the results of the time series data analysis and the implications of the results on sediment transport modeling in hebble the systematic variation in the abss and light transmissometry calibration with changes of particle size distribution caused by environmental variability is discussed a comparison of the abss estimates of particle concentration with those obtained from light transmissometers seems to indicate that the suspended particle size distribution changed surprisingly little throughout the experiment

bottom stress estimates and their prediction on the northern california continental shelf during code 1 the importance of wave current interaction abstract high quality near bottom boundary layer measurements obtained at a midshelf location 90 m water depth in the code region off northern california are described bottom tripod velocity measurements and supporting data obtained during typical spring and early summer conditions june 1981 during code 1 are analyzed to obtain bath velocity profiles and mean bottom stress and bottom roughness estimates during the time period described the mean near bottom 0 997 approximately 30 percent of the time effects induced by unsteadiness from internal waves result in some degradation of the profiles 0 96 r 0 997 the rest of the time mean stress profiles indicate the logarithmic layer is approximately a constant stress layer the near bottom flow field is composed of mean currents and oscillatory currents due to well typing mean u values estimated from measurements greater than 30 cm above the bottom have magnitudes of 0 5 1 0 cm s 1 mean stress valu

levant jet system effect of post lgm seafloor currents on nile sediment transport in the eastern mediterranean abstract sedimentary development of a continental margin is directly related to seafloor current dynamics yet the linkage between the processes remains vague due to the different time scales they represent to narrow this gap we focus on the thoroughly studied distribution system of nile derived sediments across the levant continental margin eastern mediterranean these sediments dominate the late quaternary stratigraphy of the entire margin their mobilization has been explained exclusively by longshore transport while oceanographic evidence from the basin and margin are not incorporated in the known mechanism new data indicates that longshore mechanism is part of a much larger system based on integrated interpretation of multibeam bathymetry high resolution single channel seismic reflection and oceanographic temperature salinity and chlorophyll data we suggest a jet current system mobilizes the levant surface water lsw levant intermediate water liw and atlantic water aw northwards along the margin between 0 and 400 m water depths on the seafloor contourite currents form elongated along strike morphologies below 400 m along dip gravity flows dominate sediment transport to down the slope below the eastern mediterranean deep water emdw initiation of this mechanism during the pleistocene holocene transition and not at the end of the last glacial maximum lgm indicates a gradual recovery of the thermo haline circulation current intensification in the early holocene may have also increased water stratification this comprehensive mechanism explains sediment transport along the entire depth range of the continental margin while integrating seafloor currents morphology as well as their relation to sea level rise and stratigraphy of water masses in the levant basin since the lgm given the consistency of seafloor currents throughout the holocene we propose to address them as the levant jet system

aeolian beach ridges and their significance for climate and sea level concept and insight from the levant coast east mediterranean abstract relict beach ridges of aeolian origin and associated soils are often used for inferring relative sea level and climate with contrasting results most studies link the aeolian coastal deposits to regressive phases some to high sea level stands and a few to intermediate relative sea level positions we interpret the apparent contradictions as indicating the lack of an over arching concept and the inconsistent usage of sea level related terms in this paper we present an integrated morpho sedimentological concept for a microtidal mid latitudinal coast and review existing data from the levant east mediterranean coast to evaluate the concept and to eliminate nomenclatural confusion a coastal depositional environment in a semi arid environment consists of shallow marine aeolian and alluvial facies which together form an aeolian beach ridge complex as a package of strata which respond simultaneously to sea level change a transgressive complex forms through reworking or overstepping of the coastal foredune and a regressive complex forms by downstepping under transgression the aeolian beach ridge represents the highstand deposit and its adjacent shallow marine sediment is the transgressive deposit under regression the complex represents the falling stage and the associated downdip surface marks the lowstand on the levant coast we find chronologically well constrained offlapping aeolian beach ridges as parts of six downstepping beach ridge complexes formed between 200 ka and 10 ka the complexes represent the falling stage systems tract fsst of a short lived 5th order depositional sequence when the shoreline shifted from a position close to the modern coastline to the shelf or below the shelf edge three of these fssts and their up dip and down dip super bounding surface together form the 4th order 100 ka sequence of the last interglacial glacial cycle the absence of transgressive highstand and lowstand systems tract is explained by the poor preservation potential due to the small sediment budget of the complex the falling stage complex has a high preservation potential because sediment source area increases while the sand drift potential remains above the local threshold on the levant coast sand delivery to the backshore continued during relative sea level falls for distances of up to 10 km between dune and coastline which is unprecedented in most modern analogues the significance of the dune soil succession for climate is limited because the dunes are governed by relative sea level change the vegetation response to changes in precipitation is non linear and the dune dynamics are characterised by low resilience and hysteresis

late pleistocene evolution of the continental shelf of central israel a case study from hadera abstract sea level fluctuations are a dominant mechanism that control coastal environmental changes through time this is especially the case for the successive regressions and transgressions over the last interglacial cycle which have shaped the deposition preservation and erosion patterns of unconsolidated sediments currently submerged on continental shelves the current study focuses on creating an integrated marine and terrestrial geophysical and litho stratigraphic framework of the coastal zone of hadera north central israel this research presents a case study investigating the changing sedimentological units in the study area analysis suggest these represent various coastal environments and were deposited during times of lower than present sea level and during the later stages of the holocene transgression a multi disciplinary approach was applied by compiling existing elevation raster grids bathymetric charts one hundred lithological borehole data sets and a 110 km long sub bottom geophysical survey based on seismic stratigraphic analysis observed geometries and reflective appearances six bounding surfaces and seven seismic units were identified and characterized these seismic units have been correlated with the available borehole data to produce a chronologically constrained lithostratigraphy for the area this approach allowed us to propose a relationship between the lithological units and sea level change and thus enable the reconstruction of hadera coastal evolution over the last 100 ka this reconstruction suggests that the stratigraphy is dominated by lowstand aeolian and fluvial terrestrial environments subsequently transgressed during the holocene the results of this study provide a valuable framework for future national strategic shallow water infrastructure construction and also for the possible locations of past human settlements in relation to coastal evolution through time

estimates of winter currents on the israeli continental shelf a simplified analytical model for continental shelf wind driven currents is adopted the calculated results compare favorably with extensive field measurements from two separate sources the model is used to hindcast the current climatology on the israeli continental shelf the maximum northward southward alongshore currents at 10 m water depth with a return period of 100 years are found to be 1 28 and 0 53 m s respectively

morphodynamic implications for shoreline management of the western mediterranean sector of egypt although the western mediterranean coast of egypt between sallum and alexandria 550 km long has maintained a considerable equilibrium throughout history developers have built traditional protective structures in an effort to form sheltered recreational beaches without taking into consideration its geomorphologic characteristics coastal processes and their harmful impact on the coastal environment and human safety the improper practices in this environmentally valuable region have induced us to undertake an initiative to carry out a morphodynamic analysis to provide a framework for understanding the relationship between coastal morphology and the prevailing dynamic forces based on the degree of natural protection or wave sheltering the study shoreline can be categorized into four distinct morphotypical stretches 1 high energy wave exposed shores and the outer margins of the rocky headlands 2 moderate to high wave energy beaches along semi exposed embayments and bays mostly downdrift of the rocky headlands 3 low wave energy at semi exposed headland lee sided and pocket beaches and 4 calm wave sheltered enclosing water basins for safe anchorages moorings and recreation beaches the results deducted will have practical applications for shoreline management initiatives regarding sustained sites suitable for future beachfront development such as safe swimming conditions sport facilities water intakes and sheltered areas for vessels in addition benefits realized by the understanding of the morphodynamic processes would enhance our awareness of the significance of the role of western coast morphodynamics in supporting sustainable development via shoreline management as far as sustainability is concerned the selection of appropriate sites would help avoiding or minimizing the formation of the hard structures needed for creating safe recreation beaches on a national scale results reached could provide reliable database for information that can be used in establishing a sustainable shoreline management plan which is in turn an essential part when implementing an integrated coastal zone management plan for this region of attraction

rates of particle scavenging sediment reworking and longitudinal ripple formation at the hebble site based on measurements of 234th and 210pb between 1982 and 1986 seabed and water column samples were collected on five cruises to the hebble site two particle reactive radionuclides 234th and 210pb have been used to examine rates of particle scavenging in bottom waters sediment reworking in the surface seabed and formation of longitudinal ripples settling particles at the hebble site which have been resuspended by strong bottom currents and benthic storm activity scavenge approximately 60 of the 234th half life of 24 days produced in the bottom 100 m of the water column corresponding to removal of 15 dpm cm2 234th inventories from cores collected during a single cruise show substantial variability e g 1 18 dpm cm2 over the 8 km2 study area indicating that resuspended particles are not deposited uniformly across the seabed after storm events the activity of benthic fauna and non uniform deposition over a topographically variable seabed are important processes affecting boundary layer sedimentation and the development of radionuclide inventories in surface sediments the mean 234th seabed inventory from individual cruises to the hebble area varies to a greater extent 2 to 38 dpm cm2 than the mean 210pb inventory 47 to 82 dpm cm2 because 234th inventories are dominated by sedimentary processes associated with an individual storm event whereas 210pb inventories integrate these processes over several cycles of deposition and erosion sediments at the hebble site are biologically reworked very rapidly on a 100 day time scale with 234th mixing coefficients db 1 to 33 cm2 yr comparable to values observed in nearshore environments on time scales of months to years 210pb data indicate that strong currents and benthic storm activity have eroded and redeposited the upper 5 10 cm in 17 of the 20 cores examined reoccupying field sites during the 4 year field program provided the unique opportunity to evaluate steady state models commonly used to determine rates of sediment reworking 210pb profiles and inventories showed significant temporal variations at hebble sites occupied between 1982 and 1986 steady state models should not be used to evaluate profiles of 210pb or other tracers with comparable half life in a dynamic environment like the hebble area because steady state assumptions are not justified and rates of sediment reworking can be underestimated by nearly an order of magnitude 234th and 210pb analyses of core samples from two longitudinal ripples suggest that these sedimentary features form on a time scale of months and consist of a mixture of recently deposited material from the water column and older sediment from depth the absence of 234th activity in one of the ripples indicates that these bedforms may be stable for periods of months without significant growth

velocity structure of the benthic ocean abstract velocity measurements in the outer part of the bottom boundary layer on the hatteras abyssal plain are examined for indicators of boundary layer turbulence velocity fluctuations in two frequency bands near inertial and high frequency 1 4 cph display mixed layer signatures the high frequency velocities measure primarily boundary layer turbulence the turbulence so measured is modulated on inertial and tidal time scales and extends intermittently to the mixed layer top the near inertial velocities are less energetic within the mixed layer than above and for the dominant clockwise component the mixed layer leads the interior following d asaro 1982 this is attributed to turbulent stresses which consequently must fill the mixed layer these observations suggest that the entire bottom mixed layer is at least inter mittently turbulent

periodic resuspension in baltimore canyon by focusing of internal waves high concentrations of particulate matter are frequently reported in submarine canyons this study demonstrates that in baltimore submarine canyon elevated concentrations result from periodic resuspension events the sloping bottom and v shaped topography of submarine canyons could accelerate tidal flows in the canyon axis sufficiently to cause resuspension which occurs predominantly at tidal frequencies however current meter and transmissometer data show that resuspension events are often associated with a borelike intrusion of cold water moving upslope near the canyon head an event that is consistent with the focusing of internal wave energy toward the canyon head at tidal frequencies hydrographic conditions for the focusing of energy are most favorable in late winter and early spring when stratification in the canyon is diminished direct observations reveal that the most pronounced resuspension events occur during those seasons bottom stresses generated in the canyon are sufficient to resuspend sediment along the axis at least between 200 and 800 m with little resuspension occurring deeper along the axis on the canyon walls adjacent slope or shelf during a resuspension event the sediment laden water is forced upcanyon then sloshes back down the canyon until it reaches a layer of higher density water detaches from the canyon floor and moves seaward along a density surface this is a means of transferring sediment and associated pollutants intercepted at the canyon head to deeper water across the shelf slope front over geologic time frequent resuspension and seaward transport may aid in the headward erosion of submarine canyons or at least inhibit their infilling during interglacial times

monitoring changing position of coastlines using thematic mapper imagery an example from the nile delta coastline movement due to erosion and deposition is a major concern for coastal zone management very dynamic coastlines such as sections of the nile delta coast pose considerable hazards to human use and development and rapid replicable techniques are required to update coastline maps of these areas and monitor rates of movement the synoptic capability of landsat thematic mapper imagery enables monitoring of large sections of coastline at relatively coarse 30 m spatial resolution by comparing positions of the nile delta coast in 1984 1987 and 1990 1991 mapped using a region growing image segmentation technique areas of rapid change can be identified and targeted for more detailed monitoring in the field or using higher resolution images rates of erosion and deposition can be estimated crudely and areas where change appears to be accelerating can also be identified areas of severe erosion along the nile delta coast are found to be confined to the promontories of the present day mouths of the nile at rosetta and damietta eroding shorelines are mostly flanked by accreting shorelines showing that some of the eroded material is redistributed along the coast the technique outlined here has potential to augment conventional field based surveying for monitoring shoreline changes over short timescales

holocene hydrological events and human induced environmental changes reflected in a southeastern mediterranean fluvial archive abstract the chronostratigraphy of an eastern mediterranean holocene fluvial sequence reflects global trends climate and sea level local modulations hydrological regime and storm surges and anthropogenic impact two continuous cores retrieved from the tanninim stream estuary on the carmel coast of israel are dated by optically stimulated luminescence osl to span the holocene the sedimentology and faunal assemblages are analyzed for reconstructing environmental conditions despite time gaps recognized in the fluvial successions three main depositional periods provide distinctive archives capturing natural and anthropogenic centennial to millennial changes alternations between enhanced and reduced fluvial activity associated with humid and dry climate conditions characterized the early to mid holocene fluvial record between about 7 8 and 5 7 ka and may match eastern mediterranean climate records the first humid phase from 8 to 6 ka features organic rich fine sediments and proliferating brackish ostracods foraminifera and molluscs the appearance of this biofacies indicates the initiation of seepage from the yarkon tanninim aquifer through the brackish oligohaline enot timsah springs the advancing coastline due to sea level rise starting about 5 8 ka resulted in an increasing supply of quartz sands and marine transported foraminifera relatively fast accumulation of organic rich fine grained sediments with enhanced preservation of brackish fauna during the late holocene is probably associated with maintenance of the tanninim dams during the early arab period 7th 8th centuries ce the last century has been characterized by accelerated sedimentation rates that may be associated with reduced vegetation cover due to modern human activity and by deposition by a high energy surge event this study demonstrates that the lower part of a semi arid southeastern mediterranean estuary responds to periods of climatic and sea level change on a regional scale and to human impact and abrupt past hydrological events on a local scale

quaternary sedimentology and prehistory on the mediterranean coastal plain of israel abstract the coastal plain of israel is composed primarily of nile derived quartz sand carried northward in the nile littoral cell and partly windblown on land occasional clay and gravel deposits originated in the mountains to the east are confined to the eastern end of the plain the windblown sand was subsequently consolidated by caco3 probably supplied mainly by shell fragments carried with the sand intervals between episodes of sand deposition gave sometimes rise to pedogenic process coupled by the influx of atmospheric dust carrying silt clay particles from the west south and east normally mature reddish brown loams hamra soils were formed occasionally immature gray brown sandy soils of the regosol type have formed a few red brown hamra soils contain archaeological remains but cultural remains are absent from all sandy sediments or immature sandy soils the coastal plain consists of two distinct parts the eastern part is made of early and middle pleistocene deposits while the western part contains upper pleistocene and holocene deposits the western part is characterized by several elongated shore parallel aeolianite ridges distributed on and off shore such ridges are absent in the eastern part of the coastal plain on the other hand unconsolidated sands form a considerable volume of the deposits in the eastern part but hardly exist in the western part in the eastern part of the coastal plain there are numerous lower palaeolithic sites dated 1 2 0 2 my the western part includes sites stretching from the middle palaeolithic ca 200 ky ago to the chalcolithic period ca 5 ky ago the mount carmel coast is unique in the preservation of off shore sites dated between the 9th to the 5th millennia bp submerged between 12 m below sea level and the waterline human skeletal remains were not found on the coastal plain except in these submerged sites

unique clay assemblages in the levant basin haifa bay subsurface reflect a land sea transition zone and restricted environments throughout the last 1m y abstract a subsurface sequence in haifa bay the levant basin was studied for its clay mineralogy by x ray diffraction xrd in order to examine the response of clay assemblages to sea level changes and alternating environments over a long period apparently longer than ever recorded before the study was conducted on continuous cores of three boreholes that represent 1 m y of very shallow

long term in situ calculations of kinetic energy and reynolds stress in a deep sea boundary layer long term measurements of reynolds stress and kinetic energy are necessary to characterize the bottom boundary layer during storms which transport sediment in the high energy benthic boundary layer experiment area on the nova scotia rise the benthic acoustic stress sensor current meter system employed an on board microcomputer to process 2 hz velocity vector data into 20 min averages of velocity vectors and the turbulent reynolds stress tensor the data indicate a bottom boundary layer which is usually transitional with bottom roughness scaling between viscous z0 v 9u and rough z0 ks 30 during the periods of transitional flow the logarithmic layer was not a useful indicator of boundary stress direct stress and energy measurements showed that the stress was much less than that indicated by the slope of the transitional mean logarithmic velocity profile several westward high velocity events which were modulated by a significant tidal component were recorded it appears from this data set that the mean westward flow must be accompanied by a train of internal tidal waves to achieve the velocities necessary to be the sediment transport events identified as benthic storms

patterns of nearshore sediment transport along the nile delta egypt abstract the nearshore sediment transport system along the nile delta has been determined from the response of beaches to the construction of engineering structures from the forms of geomorphological shoreline features from large scale changes in shoreline orientations due to erosion and accretion and from longshore variations in beach sand mineralogy and grain sizes the analyses reveal local patterns of erosion and accretion that have resulted from the interruption of the longshore sediment transport by jetties and groins as well as the major erosion of the promontories adjacent to the mouths of the rosetta and damietta branches of the nile river brought about by the cutoff of the supply of river sand by construction of the high aswan dam major zones of shoreline accretion are positioned to the east of the eroding promontories demonstrating that there are strong longshore gradients in the quantities of the eastward sand transport the variation east of the rosetta branch has been quantitatively evaluated from the patterns of erosion and accretion based on sediment continuity considerations a similar delta wide comparison is made between the patterns of longshore sediment movements found in this study and those calculated by others from wave refraction diagrams based on the various lines of evidence for beach erosion longshore sediment transport and shoreline accretion four nearly self contained cells have been identified in the littoral zone of the nile delta abu quir bay the eastern flanks of the rosetta and damietta promontories and the burullus central delta region

sediment contribution from israel s coastal cliffs into the nile s littoral cell and its significance to cliff retreat mitigation efforts abstract we quantify the volumetric erosion of israel s actively retreating mediterranean coastal cliffs between 2006 and 2015 with airborne lidar our results reveal annual sand contribution of 45 000 m3 from the coastal cliffs into the nile s littoral cell nlc which amounts to 50 of the annual long shore sand transport previously measured at the northern termination of the nlc accordingly we find that implementation of cliff retreat mitigation engineering efforts planned for israel s coastline can lead to a sand deficit in the nlc that may result in increased beach erosion