photogeologic analysis of impact melt rich lithologies in kepler crater that could be sampled by future missions 1 kepler is a 31 km diameter copernican age complex impact crater located on the nearside maria of the moon we used lunar reconnaissance orbiter imagery and topographic data in combination with kaguya terrain camera and other image data sets to construct a new geomorphologic sketch map of the kepler crater with a focus on impact melt rich lithologies most of the interior melt rocks are preserved in smooth and hummocky floor materials smaller volumes of impact melt were deposited in rim veneer interior and exterior ponds and lobe like overlapping flows on the upper crater wall based on shadow lengths typical flows of melt rich material on crater walls and the western rim flank are 1 5 m thick and have yield strengths of 1 10 kpa the melt rock distribution is notably asymmetric with interior and exterior melt rich deposits concentrated north and west of the crater center this melt distribution and the similarly asymmetric ray distribution imply a slightly less than 45 impact trajectory from the southeast the exposed wall of kepler displays distinct layering with individual layers having typical thicknesses of 3 5 m these are interpreted as flows of procellarum mare basalts in the impact target from the point of view of exploration numerous fractures and pits in the melt rich floor materials not only enable detailed studies of melt related processes of impact crater formation but also provide potential shelters for longer duration manned lunar missions

environmental impacts of baltim and ras el bar shore parallel breakwater systems on the nile delta littoral zone egypt this study evaluates the impacts resulting from the construction of two large scale detached breakwater systems on the nile delta coast of egypt at baltim and ras el bar beaches 18 3 km shoreline length the two protective systems were installed in a water depth of between 3 and 4 m and consist of 17 units in total each 250 m long a comprehensive monitoring program spanning the years 1990 to 2002 was implemented and included beach nearshore profiles grain size distribution of seabed sand and information related to the background coastal processes evaluation of these systems concentrates on the physical impacts on coastal morphodynamics mitigation and their design implications the beach and nearshore sedimentation erosion accretion patterns and grain texture of seabed sediment in the study areas have been substantially disrupted due to the interruption of longshore transport by the shore parallel detached breakwaters rate of shoreline and seabed changes as well as alongshore sediment volume have been substantially affected resulting in accretion in the breakwater landward sides tombolo or salient followed by downdrift erosion the preconstruction beach erosion at baltim 5 m year and at ras el bar 6 m year has been replaced respectively by the formation of sand tombolo 35 m year and salient 9 m year on the other hand beach erosion has been substantially increased in the downdrift sides of these protective systems being 20 m year at baltim and 9 m year at ras el bar further seaward the two protective systems at baltim and ras el bar have accumulated seabed sand at maximum rates of 30 and 20 cm year and associated with downdrift erosion of 45 and 20 cm year respectively strong gyres and eddies formed in the breakwater gabs have drastically affected swimmers and subsequently caused a significant number of drownings each summer averaging 35 and 67 victims year at baltim and ras el bar beaches respectively this study provides baseline information needed to help implement mitigation measures for these breakwater systems

vulnerability and fate of a coastal sand dune complex rosetta idku northwestern nile delta egypt types distribution and origin of recent sand dunes between rosetta and idku in the western sector of the nile delta egypt were investigated sand samples from the dunes beach and seafloor were studied for grain size distribution and mineralogical composition it has been found that most of the dunes in the study area have been subjected to deterioration and removal due to the construction of buildings and the international coastal highway the remnant constitutes a damaged belt of foredunes that extends from el bouseily village to the west of idku town the dune s origin is interpreted to be the result of coastal drifting and the subsequent transport of sediments of the former canopic nile branch eastward by the predominant longshore current and by aeolian processes the blown sand grains accumulated to form a belt of coastal sand dunes of original longitudinal and crescentic forms urbanization of the coast has severely altered the landscape the study area is considered vulnerable to the impacts of climate change and the expected rise in sea level the outcome of potential sea level rise is serious erosion problems are expected to be exacerbated and vast areas from land and property would be lost thus protection and preservation the remaining dunes in the study area are vital requirements for shore protection

fossils from quaternary fluvial archives sources of biostratigraphical biogeographical and palaeoclimatic evidence fluvial sedimentary archives have the potential to preserve a wide variety of palaeontological evidence ranging from robust bones and teeth found in coarse gravel aggradations to delicate insect remains and plant macrofossils from fine grained deposits over the last decade advances in quaternary biostratigraphy based on vertebrate and invertebrate fossils primarily mammals and molluscs have been made in many parts of the world resulting in improved relative chronologies for fluviatile sequences complementary fossil groups such as insects ostracods and plant macrofossils are also increasingly used in multi proxy palaeoclimatic and palaeoenvironmental reconstructions allowing direct comparison of the climates and environments that prevailed at different times across widely separated regions this paper reviews these topics on a regional basis with an emphasis on the latest published information and represents an update to the 2007 review compiled by the flag inspired igcp 449 biostratigraphy subgroup disparities in the level of detail available for different regions can largely be attributed to varying potential for preservation of fossil material which is especially poor in areas of non calcareous bedrock but to some extent also reflect research priorities in different parts of the world recognition of the value of biostratigraphical and palaeoclimatic frameworks which have been refined over many decades in the core regions for such research particularly for the late middle and late pleistocene of nw europe has focussed attention on the need to accumulate similar palaeontological datasets in areas lacking such long research histories although the emerging datasets from these understudied regions currently allow only tentative conclusions to be drawn they represent an important stage in the development of independent biostratigraphical and palaeoenvironmental schemes which can then be compared and contrasted

significance of the record provided by pleistocene fluvial deposits and their included molluscan faunas for palaeoenvironmental reconstruction and stratigraphy case studies from the english midlands abstract the vast majority of pleistocene fluvial deposits in northwest europe are of cold climate origin with the most important sediment type being coarse sands and gravels formed under nival regimes less commonly sands and silts of interglacial deposition are preserved in the lower levels of major aggradations or in channels preserved beneath them molluscan faunas are common in both types of deposit although the fine grained temperate sediments show the best preservation and the most diverse assemblages this paper will discuss the types of molluscan faunas found in fluvial deposits and assess their suitability for both climatic reconstruction and stratigraphic studies while it has been clear for many years that reliable local environmental reconstructions can be made using mollusca they have been less used for regional climatic assessment work in england over the past thirty years shows that faunas obtained from fluvial sediments particularly if they contain both freshwater and terrestrial species can provide a basis for regional climatic reconstruction mollusca may also allow the separation from each other of interglacials and interstadials and permit these episodes to be more precisely defined than is allowed by other means such as palynology molluscan faunas may offer potential for the identification of temperature episodes which may have the same climatic status as interglacials but which are not recognised as such by other palaeontological evidence such as pollen the use of molluscan faunas for biostratigraphy has been firmly rejected by previous authors however recent work concentrating on sites of similar facies within single catchments has shown that both presence and absence of individual species particularly those now exotic to the british isles e g belgrandia marginata michaud and corbicula fluminalis muller can be a useful guide to relative age examples illustrating the significance of these faunas in the stratigraphic record are largely taken from the fluvial deposits of the major rivers of the english midlands warwickshire avon great ouse nene but reference is also made to other studies on the deposits of the thames the ages of the faunas described range from the cromerian interglacial to the devensian glacial stage and includes data from sites in integlacials identified in the stratigraphic record but so far not formally named

alexandria nile delta coast egypt update and future projection of relative sea level rise previous studies have indicated that the nile river deltaic plain is vulnerable to a number of aspects including beach erosion inundation and relatively high rates of land subsidence this issue motivates an update and analysis of new tide gauge records from which relative sea level changes can be obtained estimated rates from five tide gauges are variable in terms of magnitude and temporal trend of rising sea level analysis of historical records obtained from tide gauges at alexandria rosetta burullus damietta and port said show a continuous rise in mean sea level fluctuating between 1 8 and 4 9 mm year the smaller rate occurs at the alexandria harbor while the higher one at the rosetta promontory these uneven spatial and temporal trends of the estimated relative sea level rise rslr are interpreted with reference to local geological factors in particular holocene sediment thickness subsidence rate and tectonism are correlated with the estimated rates of relative sea level change from the relatively weak correlation between them we presume that tectonic setting and earthquakes both recent and historical ones contribute more to accelerated rslr than that of dewatering and compression dewatering of holocene mud underlying the nile delta plain as a result large areas of the coastal plain have been subsided but some sectors have been uplifted in response to tectonic activities of thick underlying older strata projection of averaged sea level rise trend reveals that not all the coastal plain of the nile delta and alexandria is vulnerable to accelerated sea level rise at the same level due to wide variability of the land topography that includes low lying areas high elevated coastal ridges and sand dunes accretionary beaches and artificially protective structures interaction of all aspects tectonic regime topography geomorphology erosion rate and rslr rate permitted to define risk areas much vulnerable to impacts of sea incursion due to accelerated sea level rise

new evidence for complex climate change in mis 11 from hoxne suffolk uk the climatic signal of marine isotope stage mis 11 is well documented in marine and ice sheet isotopic records and is known to comprise at least two major warm episodes with an intervening cool phase terrestrial records of mis 11 though of high resolution are often fragmentary and their chronology is poorly constrained however some notable exceptions include sequences from the maar lakes in france and tenaghi philippon in greece in the uk the hoxnian interglacial has been considered to correlate with mis 11 new investigations at hoxne suffolk provide an opportunity to re evaluate the terrestrial record of mis 11 at hoxne the type hoxnian interglacial sediments are overlain by a post hoxnian cold temperate sequence the interglacial sediments and the later temperate phase are separated by the so called arctic bed from which cold climate macroscopic plant and beetle remains have been recovered the later temperate phase was deposited during an episode of boreal woodland and is associated with the artefacts a diverse vertebrate fauna and molluscs new amino acid geochronological data and biostratigraphical considerations suggest that the post hoxnian sequence correlates with late substages of mis 11 the paper further investigates the correlation of the sequence at hoxne with the palynological sequences found elsewhere in europe and adjacent offshore areas

variation of the lunar highland surface roughness at baseline 0 15 100 km and the relationship to relative age we report the surface roughness analysis of the lunar highlands for the baseline range 0 15 100 km we use the median differential slope m to investigate the scale dependency of the roughness and derive the global m distribution from selene laser altimeter and terrain camera data while m l versus baseline l km plots vary among different highland types all highlands commonly show a peak at 3 30 km the pre nectarian surface shows a relatively large m 20 30 km our analysis is supported by the simulation of synthetic surface cratering models and crater statistics in our simulation a peak of m 30 km is successfully reproduced the actual crater density shows good correlation with an empirical roughness indicator however a large part of the nectarian surface shows a peak at 6 9 km baseline this peak may be caused by secondary craters and ejecta deposit textures from the nectarian system basins

occurrence and mechanisms of impact melt emplacement at small lunar craters abstract using observations from the lunar reconnaissance orbiter camera lroc we assess the frequency and occurrence of impact melt at simple craters less than 5 km in diameter nine hundred and fifty fresh randomly distributed impact craters were identified for study based on their maturity albedo and preservation state the occurrence frequency and distribution of impact melt deposits associated with these craters particularly ponded melt and lobate flows are diagnostic of melt emplacement mechanisms like larger craters those smaller than a few kilometers in diameter often exhibit ponded melt on the crater floor as well as lobate flows near the crater rim crest the morphologies of these deposits suggest gravity driven flow while the melt was molten impact melt deposits emplaced as veneers and sprays thin layers of ejecta that drape other crater materials indicate deposition late in the cratering process the deposits of fine sprays are particularly sensitive to degradation exterior melt deposits found near the rims of a few dozen craters are distributed asymmetrically around the crater and are rare at craters less than 2 km in diameter pre existing topography plays a role in the occurrence and distribution of these melt deposits particularly for craters smaller than 1 km in diameter but does not account for all observed asymmetries in impact melt distribution the observed relative abundance and frequency of ponded melt and flows in and around simple lunar craters increases with crater diameter as was previously predicted from models however impact melt deposits are found more commonly at simple lunar craters i e those less than a few kilometers in diameter than previously expected ponded melt deposits are observed in roughly 15 of fresh craters smaller than 300 m in diameter and 80 of fresh craters between 600 m and 5 km in diameter furthermore melt deposits are observed at roughly twice as many non mare craters than at mare craters we infer that the distributions and occurrences of impact melt are strongly influenced by impact velocity and angle target porosity pre existing topography and degradation additionally areally small and volumetrically thin melt deposits are sensitive to mixing with solid debris and or burial during the modification stage of impact cratering as well as post cratering degradation thus the production of melt at craters less than 800 m in diameter is likely greater than inferred from the present occurrence of melt deposits which is rapidly affected by ongoing degradation processes

the importance of symbiont bearing benthic foraminifera for west pacific carbonate beach environments abstract in the tropical central and west pacific as well as in the east indian ocean symbiont bearing benthic foraminifera often are the main producers of calcium carbonate grains deposited at beaches the proportion of foraminiferal tests in medium sized to coarse sand grains may range from 20 to 95 this depends on two factors productivity and transport because foraminifers do not live on or in the sandy bottom near the beaches but prefer firm substrate in high energy environments close to the front of coral reefs foraminiferal tests are produced in extreme numbers on the reef crest of sesoko island okinawa japan 0 6 kg m 2 year 1 which is covered by macroalgae or in the transition zone between the crest and the reef moat 1 3 kg m 2 year 1 empty tests released by reproduction or death are entrained at the reef crest by waves and transported by currents this transport depends on the direction and intensity of currents connecting the habitat reef crest and transition to moat with the deposition area central moat lagoon beach habitat destruction and or the interruption or diversion of water flow hinders the accumulation of foraminiferal tests at the beach where deepening the moat intensifies beach parallel currents supply to and deposition at the beach are reduced while the remaining sand is eroded by tropical cyclones understanding the ecology especially population dynamics of larger foraminifera in combination with factors influencing the transport of empty tests is essential to preserve the balance between deposition and removal of sand at carbonate beaches in the west pacific and east indian ocean

pollen analytical biostratigraphy of the last five climatic cycles from a long continental sequence from the velay region massif central france in the volcanic region of velay massif central france lake sediment sequences derived from maar craters situated close to one another ribains praclaux and lac du bouchet have been correlated on the basis of tephrostratigraphical analyses this has enabled the construction of a sequence 2980 pollen spectra that begins during the glaciation preceding the holsteinian and ends in the present this sequence covers the period from 450 ka i e from the end of marine oxygen isotope stage 12 to the present time and includes five climatic cycles the study of a second core from the praclaux site completed the long velay sequence the biostratigraphy of the whole sequence is described in detail and illustrated by a synthetic and simplified pollen diagram thirteen temperate forest episodes interglacials or interstadials and as many cold periods glacials or stadials are defined each temperate episode is characterised by particular forest development and vegetation dynamics and all of them with the exception of the holocene begin and end with a pinus forest the vegetation dynamics observed during the holocene resemble more closely those recorded during the interstadials than during the interglacials copyright 2000 john wiley sons ltd

long term shoreline changes and the concentration of heavy minerals in beach sands of the nile delta egypt abstract analyses have been undertaken of shoreline positions established from beach profile surveys at 65 positions along the coastline of the nile delta spanning the years 1971 to 1990 the analyses identify long term linear trends as well as any cycles in the horizontal movement of shoreline positions the results reveal longshore patterns wherein erosion along a stretch of coast gives way to accretion in an adjacent stretch defining a subcell within the overall littoral system of the delta the rate of shoreline retreat has been greatest along the rosetta promontory 106 m yr and damietta promontory 10 4 m yr significant erosion has also occurred along the central bulge of the delta coast but at a lesser rate 6 5 m yr areas of accretion exist within the saddles or embayments between the promontories with the maximum shoreline advance averaging about 13 m yr the identified patterns of erosion versus accretion along the delta reflect the natural processes of wave induced longshore currents and sediment transport associated with this longshore sediment movement is a selective transport of different minerals according to their densities and grain sizes with the light minerals quartz and feldspar having the highest advection rates and the dense opaque minerals the lowest rates tending to remain behind as a lag within the erosion areas as a result of this longshore grain sorting paralleling the patterns of shoreline erosion versus accretion there are correlations between the rates of shoreline change and the heavy mineral contents and mean grain sizes of the beach sediments these large scale delta wide patterns are affected somewhat by local shoreline changes and mineral variations induced by the construction of jetties or shoreline protection structures

deposition and taphonomy of earthworm granules in relation to their interpretative potential in quaternary stratigraphy calcium carbonate granules up to 2 5 mm in size are commonly found in quaternary soils and sediments but have only rarely been used for any form of interpretation growing interest in recent years has focused on the concentration patterns in stratigraphy containing buried land surfaces and the possibility of dating the granules making sense of either of these approaches requires a basic understanding of granule types together with their modes of accumulation and destruction in stratigraphy details of the formation morphology deposition and post depositional changes are discussed along with the necessary ecological and pedological information on earthworm behaviour and effects then summarised into a framework for interpretations copyright 2006 john wiley sons ltd

characterization of space weathering from lunar reconnaissance orbiter camera ultraviolet observations of the moon we investigate the effects of space weathering at ultraviolet wavelengths using a near global seven band 321 689 nm mosaic from the lunar reconnaissance orbiter camera lroc wide angle camera wac we confirm that for moderate to high iron compositions 5 wt feo the steeply positive uv slope at wavelengths 415 nm shallows with increasing exposure to space weathering we measure these differences in lroc wac data as variations in the 321 415 nm ratio which has low values for fresh craters in the mare and moderate iron highlands for low iron highland compositions the break in slope occurs at shorter wavelengths and it is instead the 321 360 nm ratio that increases with exposure to the space weathering environment whereas the 321 415 nm ratio appears to be largely controlled by the degree of shock experienced during the impact the effects of shock may be more important at highland craters because modest shock pressures result in the solid state transformation of plagioclase to its glass equivalent maskelynite and can help distinguish between primary shocked ejecta and locally exposed fresh material in rays while all of the fresh craters we examined have uv spectral properties consistent with substantial alteration due to space weathering the uv spectra of lunar swirls magnetically shielded from the solar wind are consistent with exposure of immature crystalline material together these results suggest that lunar space weathering is dominated by the solar wind and saturates in the uv at is feo values of 40 submature

patterns of beach sand sorting and shoreline erosion on the nile delta abstract rapid erosion has occurred on the beaches of the nile delta in response to dam construction that has cut off the river sediment supply this erosion is greatest adjacent to the two distributary mouths with shoreline retreat rates up to 60 m per year the eroded sand is carried alongshore away from the river mouths and deposited in areas of shoreline accretion these patterns of shoreline erosion and deposition are reflected in the mineralogy of the beach sands on a delta wide scale high density opaques garnet and zircon are concentrated in the erosion areas to form black sand placers lower density hornblende as well as quartz and feldspars are preferentially transported out of the erosion areas and deposited in the stretches of accreting shoreline a detailed analysis of these sorting patterns has been undertaken with beach samples from abu quir bay at the western end of the delta concentrations of opaques zircon rutile and garnet decrease exponentially with longshore distance from the river mouth while augite and hornblende increase exponentially the coefficients in the exponential equations are found to be a function of mineral density demonstrating the importance of this grain property in mineral sorting leading to the observed compositional variations along the shores of the nile delta

geology of the king crater region new insights into impact melt dynamics on the moon 1 new geologic sketch maps and digital elevation models for king crater and the surrounding lunar farside highlands were created from lunar reconnaissance orbiter camera lroc wide angle camera wac and narrow angle camera nac images nac images reveal that high volume impact melt accumulations exhibit evidence of dynamic processes during and following emplacement that resulted in downwarped zones and other morphologic anomalies visible at the 50 cm pixel scale among the most significant of these forms are negative relief features some of which may represent evidence for near surface caverns offering points of access to subsurface environments and possible shelter from surface hazards other negative relief features may represent regions of extension and separation in response to possible subsurface drainage together with isostatic readjustments contraction and or compaction in the cooling impact melt crater counts on the continuous ejecta blanket suggest a late eratosthenian to copernican age for king crater which is older than the estimate of young 1977 but consistent with those of others

new insight into lunar impact melt mobility from the lro camera 1 the lunar reconnaissance orbiter camera lroc is systematically imaging impact melt deposits in and around lunar craters at meter and sub meter scales these images reveal that lunar impact melts although morphologically similar to terrestrial lava flows of similar size exhibit distinctive features e g erosional channels although generated in a single rapid event the post impact mobility and morphology of lunar impact melts is surprisingly complex we present evidence for multi stage influx of impact melt into flow lobes and crater floor ponds our volume and cooling time estimates for the post emplacement melt movements noted in lroc images suggest that new flows can emerge from melt ponds an extended time period after the impact event

differentiation of the british late middle pleistocene interglacials the evidence from mammalian biostratigraphy abstract acknowledgement of the climatic complexities of the marine oxygen isotope 18o record has inspired fresh investigations into methods of identifying and separating interglacial deposits on land biostratigraphical analysis of fossil mammalian assemblages particularly those from long fluvial sequences has proved to be a uniquely valuable technique in the differentiation of the various temperate episodes of the late middle pleistocene in britain thereby enabling a sequence of diagnostic mammalian assemblage zones to be established the scheme has provided an important means of correlation between geographically distant localities and between different types of depositional environment using mammalian biostratigraphical information this paper explores the evidence for three post anglian interglacials prior to the last ipswichian interglacial correlated with stages 11 9 and 7 of the oxygen isotope record and presents the case for the recognition of much smaller scale environmental and climatic oscillations within these interglacials possibly corresponding to marine isotopic substages

erosion and accretion rates and their associated sediment characters along ras el bar coast northeast nile delta egypt beach profile data covering the coast of ras el bar northeast nile delta collected during the years from 1990 to 2002 combined with landsat images for the area and sedimentological investigation have been used to identify beach and nearshore seafloor sediment changes along the coast of ras el bar two accretion sectors and one of erosion have been recognized the first accretion sector is located west of damietta harbour where the harbour jetties have halted the littoral transport while the second one is behind a system of detached breakwaters protecting ras el bar resort both the two sectors are characterized by growing shoreline with maximum rates 15 and 10 m year respectively also they have maximum nearshore seafloor accretion rates of 18 and 22 cm year respectively the erosion sector is located east of damietta port and has a maximum rate of shoreline retreat 10 m year erosion of its nearshore seafloor is indicated recording a maximum rate of 20 cm year the rate of net sediment volume change in the area indicates shifting of the accretion sector ii westward responding to installation of the new breakwaters unit the two accretion sectors are characterized by dominance of moderately sorted fine sands in their shore area which change seaward into less sorting very fine sands beach sands of the eroded sector are poorly sorted medium grain size the dominant constituents of heavy mineral species in beach and sea bottom sands are the characteristic assemblages of the nile deposits the sands of the eroded zone are relatively enriched in monazite zircon tourmaline garnet and rutile

full scale monitoring study of a submerged breakwater palm beach florida usa abstract in an attempt to reduce beach erosion and wave impact on a protective seawall an experimental proprietary submerged breakwater reef of 1 260 m length was installed in a water depth of approximately 3 m off the town of palm beach florida to provide a basis for evaluating the effects of this installation a comprehensive field monitoring program was carried out and included wave measurements beach and offshore profiles settlement of the units local scour data and information related to the background coastal processes the system consists of 330 units 57 of which were installed in the summer of 1992 and the remainder in the summer of 1993 monitoring surveys available up to june 1995 are presented herein the wave height reduction attributable to the reef ranges from 5 for the lower waves and higher tides to 15 for the higher waves and lower tides the profile data documented erosion in the entire monitored area with the greatest erosion landward of the reef changes in profile data were consistent with and are interpreted as due to water conveyed over the submerged breakwater as mass transport a partial ponding of this water due to its return flow being impeded by the presence of the breakwater resulting in a portion being redirected as longshore currents these longshore currents transport sand from landward of the breakwater with deposition occurring near the south end of the system in the direction of the predominant natural transport although these breakwater induced longshore currents were not documented in the monitoring program the mechanisms are supported by the patterns of erosion and deposition by a model study carried out to evaluate installation of a submerged breakwater at a different location and by previous documentation and discussion of the phenomenon in the available literature results obtained here are interpreted in terms of design implications

modelling morphological processes in the vicinity of shore parallel breakwaters abstract a coastal area morphological modelling system is used to investigate the planform development tombolo or salient behind a single surface piercing detached breakwater a quasi three dimensional q3d description of the flow and the sediment transport together with a revised bed level update scheme were incorporated recently in the morphological modelling suite applied in the present investigation the q3d sediment transport formulation used allows simulating beach profile evolution and planform development simultaneously several breakwater layouts were investigated in a series of tests in which the incident wave condition was taken as constant in time the investigation was done for surface piercing shore parallel breakwaters in a non tidal environment the morphological simulation results for the planform shape agree qualitatively with field observations and predictions from empirical rules using the simulation results simple design curves for surface piercing breakwaters are derived the importance of properly accounting for the influence of wave diffraction when modelling sediment transport and morphology in the vicinity of shore parallel structures is also investigated the present paper summarises much of the work performed at dhi water environment over the past 10 years within the field of coastal area morphological modelling

modelling of morphological changes due to coastal structures two different concepts are applicable to model the nearshore morphodynamics the first one takes into account only final consequences of acting mechanisms and is aimed at the prediction of long term trends in beach development another approach implies the modelling of the whole suite of elementary processes responsible for changes in nearshore bottom topography during a given storm and it is the approach used in the present work a coastal area model complex is proposed that allows to reproduce the local morphological changes due to both the natural processes and the influence of coastal structures such as a groin a detached breakwater and a navigable channel underwater trough consisting of a traditional series of basic components the model differs from other ones in essential aspects concerning the treatment of transport mechanisms in particular the determination of wave induced near bed mean flow is based on the hypothesis that the direction and magnitude of bottom drift depend on difference between the actual rate of energy dissipation and its threshold value marking the flow reversal point this hypothesis is shown to explain a general trend of cross shore mean flow distributions observed in the nearshore region besides the influence of the wave breaking process on sediment suspension is taken into account and the contribution of the swash zone to total sediment transport is included examples of computed morphological response are represented to demonstrate the model capability a satisfactory agreement of computations with available data is pointed out

processes reshaping the nile delta promontories of egypt pre and post protection abstract shoreline positions established from beach profile surveys combined with wave data are jointly analyzed as a function of their contribution to coastal processes to investigate the interaction between waves shoreline orientation and coastal structures along the nile delta promontories rosetta burullus and damietta repeated beach profile surveys along the promontory sectors 64 km long in total have been analyzed to determine rates of shoreline changes prior to construction 1971 1990 and after construction of protective structures 1990 2000 the behavior of coastline pre and post construction indicates that coastal erosion fronting protective structures has declined in the case of the seawalls at the tips of the rosetta and damietta promontories or has been partially replaced by sand accumulation in the case of detached breakwaters at baltim east of burullus promontory and at ras el bar west of the damietta promontory as a consequence downdrift erosion has been initiated in local areas adjacent to these structures in the direction of longshore sediment transport the 5 km long seawall protecting the rosetta promontory has stopped the dramatic erosion of this highly eroded area formerly shoreward retreated 88 m year with adverse local erosion at its west and east ends being 3 and 13 m year respectively similarly the 6 km long seawall built on the eastern tip of the damietta promontory still under construction has nearly stopped the severe erosion which was formerly 10 m year the detached breakwaters at both baltim and at ras el bar have accumulated sand at accretion rates of 37 and 14 m year respectively this sand accumulation is associated with downdrift erosion of 25 and 13 m year at baltim and ras el bar respectively results reaffirm that the original erosion accretion patterns along the nile delta promontories have been reshaped due to the massive protective structures built during the last decade this reshaping along the examined promontories is generally controlled by the temporal variability in the intensity and reversibility of wave directions and associated longshore currents coastline orientation and by the existing coastal protection structures

the position and context of middle palaeolithic industries from the ebbsfleet valley kent uk the late middle pleistocene sites in the ebbsfleet valley kent uk have yielded archaeological assemblages critical to understanding the early middle palaeolithic of northwestern europe despite a long history of research the nature and context of these assemblages are still poorly understood this paper clarifies the stratigraphic environmental and archaeological records at ebbsfleet these reflect a cold warm cold sequence of climatic events preserved within part of the taplow mucking formation of the thames marine isotope stage mis 8 7 6 levallois artefacts are shown to be restricted to the lower part of the ebbsfleet channel sequence phases i and ii and are assigned to late mis 8 early mis 7 this material is associated with fauna indicative of open environments during both cool and temperate conditions handaxe assemblages are recorded from higher up the sequence phases iii v but have been redeposited from higher terrace units nearby no primary context archaeology is apparent during these later phases of aggradation this may indicate that humans abandoned the site once available raw material became inaccessible and may also reflect a decline in human presence in britain during the latter part of mis 7 copyright 2010 john wiley sons ltd

human induced changes in the geomorphology of the northeastern coast of the nile delta egypt abstract landsat enhanced thematic mapper imagery etm of 2002 and aerial photography of 1955 combined with published charts and field observations were used to interpret geomorphological changes in the coastal zone between kitchener drain and damietta spit in the northeastern nile delta previously recognized as a vulnerable zone to the effects of any sea level rise resulting from global warming the interpretation resulted in recognition of several changes in nine identified geomorphological land types beach and coastal flat coastal dunes agricultural deltaic land sabkhas fish farms manzala lagoon saltpans marshes and urban centers reclamation of vast areas of the coastal dunes and of manzala lagoon added about 420 km2 to the agricultural deltaic land about 48 km2 of sand dunes marshes sabkhas and salt pans have been converted to productive fish farms the main urban centers have expanded and new urban centers damietta harbor and the new damietta city have been constructed at the expense of vast areas of manzala lagoon coastal dunes and backshore flats as the consequence of human activities the size of manzala lagoon has been reduced to less than 50 short term shoreline changes along the coast of the study area established from beach profile survey spanning the years of 1990 to 2000 reveal longshore patterns of erosion versus accretion the rate of shoreline retreat has increased in the downdrift side of damietta harbor 14 m year whereas areas of accretion exist within the embayment of gamasa and in the shadow of ras el bar detached breakwater system with a maximum shoreline advance of 15 m year a sandy spit 12 km long has developed southeast of damietta promontory these erosion accretion patterns denote the natural processes of wave induced longshore currents and sediment transport in addition the impact of man made coastal protection structures

responses of ras el bar seafloor characteristics to the protective engineering structures nile delta egypt bathymetry of the seafloor in the area in front of ras el bar coast the characters of the seafloor sediments and the effects of protective structures on seafloor bathymetry were examined seafloor depths in front of ras el bar seawall ranged between 2 and 4 m these depths coupled with wave climate result in waves breaking directly onto the wall and exerting high dynamic pressures on the area at the structure s toe the sandy seafloor in front of the wall has been scoured sea water has undermined the wall causing removal of sediment destabilization of its slope and the whole face of the wall has slipped toe protection in the form of a rocky apron is required to prevent such damage west of the seawall the constructed breakwater system has affected the bathymetry of the seafloor in the area shoaling and submerged spits have been formed in the shadow of each breakwater unit the gaps between the breakwater units have attained deep depths and steep slopes scours and steep slopes adjacent to the head of the breakwater units have been recorded seaward of the breakwater system deeper depths and gentle slopes characterize the seafloor offshore onshore current and sediment movements toward the northeast is inferred from the configuration of the bottom contour lines

natural and anthropogenic influences in the northeastern coast of the nile delta egypt landsat enhanced thematic mapper imagery etm of 2002 and aerial photography of 1955 combined with published charts and field observations were used to interpret coastal changes in the zone between kitchener drain and damietta spit in the northeastern nile delta previously recognized as a vulnerable zone to the effects of any sea level rise resulting from global warming the interpretation resulted in recognition of several changes in nine identified geomorphological land types beach and coastal flat coastal dunes agricultural deltaic land sabkhas fish farms manzala lagoon saltpans marshes and urban centers reclamation of vast areas of the coastal dunes and of manzala lagoon added about 420 km to the agricultural deltaic land about 48 km of backshore flats marshes salt pans and manzala lagoon have been converted to productive fish farms the main urban centers have expanded nearly 12 1 km2 have been added to their areas and new urban centers damietta harbor and the new damietta city with total area reach of 35 3 km2 have been constructed at the expense of vast areas of manzala lagoon coastal dunes and backshore flats as a consequence of human activities the size of manzala lagoon has been reduced to more than 65 shoreline changes have been determined from beach profile survey 1990 2000 and comparison of 1955 aerial photographs and etm satellite image of 2002 reveal alongshore patterns of erosion versus accretion the short term rate of shoreline retreat 1990 2000 has increased in the downdrift side of damietta harbor 14 m year whereas areas of accretion exist within the embayment of gamasa and in the shadow of ras el bar detached breakwaters system with a maximum shoreline advance of 15 m year a sandy spit 12 km long has developed southeast of damietta promontory these erosion accretion patterns denote the natural processes of wave induced longshore currents and sediment transport in addition the impact of man made coastal protection structures

vegetation history of the marine isotope stage 7 interglacial complex at ioannina nw greece abstract a new pollen record of the penultimate interglacial complex corresponding approximately to marine isotope stage mis 7 ca 186 000 245 000 years before present has been generated in core i 284 from the ioannina basin in northwest greece it represents the highest resolution terrestrial record for this interval available to date with a mean sampling interval of 200 years the sequence records four forested intervals correlated with mis 7e 7c 7a and a sub orbital scale event following 7a but within mis 7 the longest and most complete warm stage in terms of vegetational succession is mis 7c while the succession in mis 7e appears to be truncated by a shift to colder drier climatic conditions the results of biomisation suggest that during all of these intervals winter temperatures in nw greece remained lower than during the eemian or holocene while smaller populations of sclerophyllous taxa indicate that summers may have been wetter intervening intervals of open vegetation are correlated with mis 7d 7b and an oscillation following 7a low tree pollen percentages during mis 7d are interpreted as reflecting very cold and dry conditions concomitant with a period of low northern hemisphere insolation which resulted from a rare combination of minimum obliquity and maximum precession higher tree pollen percentages throughout mis 7b by contrast are indicative of relatively mild conditions in agreement with marine temperature and ice volume records sub orbital scale oscillations in tree population extent are also recorded in the new i 284 record suggesting that just as in the last climatic cycle nw greece was affected by rapid climatic oscillations that are associated with changes in the north atlantic