total engineering geology approach applied to motorway construction and widening in the netherlands part i a pragmatic approach abstract the current practice of site investigation for motorways in soft soil areas like the western netherlands can be described as an engineering approach rather than an engineering geology approach after a highlight of the engineering geological concerns related to building line infrastructures on soft soils the dutch practice of site investigation is critically reviewed then a new pragmatic methodology is suggested it combines 1 50 000 lithostratigraphical models of the subsurface archived geological and geotechnical data airborne laser surface altimetry data walk over survey observations and low cost geoelectric and electromagnetic data in that order a conceptual model is produced that breaks down the subsurface into terrain units formations members and types and highlights expected heterogeneities ground heterogeneities are then classified based on their mapped geology and geomorphology surface altimetry and geophysical signatures cone penetration tests are ordered to map a limited set of representative heterogeneities the complete profile of all heterogenieties is obtained by matching geological geophysical and altimetry signatures with the reference set in a companion paper this new methodology is applied to motorway widening on the tidal deposits of the western netherlands

frequency characteristics of acoustic emission in rocks under uniaxial compression and its relation to the fracturing process to failure acoustic emission generated during the uniaxial compression of brittle rocks were counted after band pass filtering throughout the whole process from application of load to failure the count rate monitored through a low pass window was compared statistically with the monitored through a high passs window the emission rate monitored through a low pas window increases more rapidly than that monitored through a high pass window as rock approaches failure two possible explanations for this effect are 1 generation of larger cracks or coalescence of cracks into larger sizes and 2 the relative attenuation of higher frequency wave components this finding is consistent with past observations i e the relative number of large amplitude events increases i e a decrease in b value as rock approaches failure we suggest that larger cracks tend to generate events with larger amplitudes and containing lower frequency components the frequency characteristics of acoustic emissions are used to characterize the microfracturing processes leading to failure the beginning of a sequence of acoustic emission activity is discussed in relation to the stress strain curve and the onset of dilatancy the present observations may be utilized in understanding structural instability of a region where rockbursts or earthquakes can potentially occur if a sizable microseismicmore population is observed through sensors placed near the fault then a potential exists for predicting major earthquakes less

characteristic variations of sea surface temperature with multiple time scales in the north pacific abstract temporal evolution and spectral structure of sea surface temperature sst anomalies in the north pacific over the last 37 years are investigated on the three characteristic time scales shorter than 24 months hf 24 60 months es and longer than 60 months dc the leading empirical orthogonal function eof for the dc time scale is characterized by a zonally elongated monopole centered at around 40 n 180 the leading eof for the hf time scale is somewhat similar to that for the dc time scale although there are two centers of action with the same polarity at the mid and western pacific the leading eof for the es time scale however exhibits a different pattern whose center of action at the mid pacific is located farther southeastward in the time evolution of the sst anomalies associated with the leading eof of the dc time scale several anomaly periods can be identified that last five years or longer the transition from a persistent period to another with the opposite polarity is gene

geological and industrial implications of extensive dilatancy anisotropy extensive dilatancy anisotropy is the hypothesized distribution of stress aligned fluid filled microcracks pervading most rocks in the earth s crust the geometry of the cracks and the aligning stress field can be monitored by analysing the waveforms of shear waves propagating through the rockmass the ability to estimate some of the parameters of the crack and stress geometry by analysing shear wave particle displacements has widespread implications

attenuation of explosion generated pulse in rock masses recordings were made of seismic pulses by explosive sources in rock underground at mount isa mine queensland australia analysis of the experimental results in light of the theory of kjartansson 1979 indicates that the simple rise time law tau tau sub 0 ct q is inadequate for describing the attenuation of seismic pulses generated by a realistic source the rise time law makes no allowance for the spectral characteristics of the source except by assigning a value of tau sub 0 to each source and is an oversimplification of the process of source propagation through rocks consequently the constant c is source dependent an alternative method of estimating pulse attenuation is presented which overcomes the difficulties inherent in the rise time law

radiocarbon dated sediment sequences from the belgian coastal plain testing the hypothesis of fluctuating or smooth late holocene relative sea level rise the late holocene deposits of the coastal lowlands bordering the southern north sea were formed by a renewed expansion of the tidal environment replacing freshwater peats the sea level history during the last 2500 years inferred from the post peat deposits containing little to no datable organic material is characterized by two conflicting schools of thought the first one supports a smooth sea level curve the second approach underpins fluctuating sea level changes the fluctuating approach also uses facies variations recorded in the post peat deposits to provide a chronostratigraphical subdivision linked to transgressions and regressions this paper examines the controlling factors responsible for the facies variations in the post peat deposits in order to test the approach of the fluctuating sea level the results of sedimentological investigation coupled with radiocarbon dates of intertidal shells from four shallow outcrops located in nearby sand filled late holocene tidal channels in the belgian

quaternary geological mapping of the lowlands of the netherlands a 21st century perspective old borehole descriptions modern lithostratigraphical classification and geostatistics have been combined in recent geological mapping in the netherlands recent developments in geostatistics and the increased computing capacity of personal computers enable three dimensional geological mapping based on already available data the data originate from a mapping programme at the scale of 1 50 000 that was started in the 1950s by the national geological survey rijks geologische dienst although started on a lithostratigraphical basis the increased use of radiocarbon dates since the 1950s influenced the map legend the map units were largely defined by age boundaries that were supposed to coincide with transgressions and regressions more recent research revealed that not only sea level but also regional basin topography sediment supply and regional neo tectonics are important factors controlling coastal development the netherlands institute of applied geoscience tno national geological survey the successor of the rijks geologische dienst recently redefined the classification of holocene coastal and alluvial deposits in a purely lithostratigraphical way the old borehole descriptions contain purely lithological descriptions as well as interpretations that were derived from those descriptions the larger part of the originally defined map units represents boundaries that characterise a change in lithology by returning to the original lithological descriptions the borehole data and the geological maps are applicable in the new lithostratigraphical framework they are now used in modern three dimensional geological mapping modelling of the subsurface these models are very useful for applied geological research 2004 elsevier ltd and inqua all rights reserved

a rotated eof analysis of global sea surface temperature variability with interannual and interdecadal scales abstract spatiotemporal variability of preferred global scale sea surface temperature anomaly patterns is documented applying a varimax rotated empirical orthogonal function r eof analysis to monthly mean sst anomalies the present study focuses especially on the interdecadal variability of leading r eof modes it is first found that temporal variability of r eof1 has a quasi periodicity of 2 5 years and coincides quite well with the occurrence of the enso event hence this mode can be identified with the enso mode and distinguished from the other modes dominated by interdecadal variability the authors find that r eof2 typically shows the dominance of interdecadal variability and signals of the enso phenomenon are removed this mode is characterized by increasing indian ocean sst and decreasing central north pacific sst around 40 50 n in the recent ten or more years a further indication is that both r eof3 and r eof4 which show the dominance of interdecadal variability are fundamentally regarded a

quaternary glaciations of northern europe this paper presents the outcome of a workshop held in berlin in february 2009 concerned with current research on the glacial history of northern europe including the british isles the methodologies presently used to resolve this topic are outlined particular attention is given to new analytical methods deriving from high resolution remote imaging of glacial terrain both on land and on the sea bed key new stratigraphic sections higher resolution results from conventional geochronological methods like radiocarbon and more recently developed technologies such as luminescence and cosmogenic radionuclide dating the relationships between the results derived from these two methods are discussed in further detail along with possible explanations for these differences an outline of a most likely glacial history of the scandinavian and british and irish ice sheets is presented along with possible links to global climate change as represented by the marine isotope mis record tentative evidence for glaciation is identified in mis 22 16 12 10 8 6 4 and 2 and correlations of phases within the last glaciation are also explored for both the scandinavian and british and irish ice sheets the results show that the character and extent of glaciation in different parts of the region are not synchronous and much more geochronological work is required before regional correlations can be established with confidence

effects of diagenesis and clays on compressional velocities in rocks experimental results at ultrasonic frequencies in brine or water saturated samples cut perpendicular to bedding demonstrate that compressional velocities vary linearly with porosity and volume fraction clay in detrital silicate rocks characterized by pores with low aspect ratios p wave velocity is more sensitive to porosity than clay content obeying the empirically derived expression vp 2 4c 8 6 5 8 at 800 bars confining pressure and 400 bars pore pressure where the units of vp are kilometers per second is the volume fraction pores and c is the volume fraction clay deviations from this equation are less than 2 with the exception of the high pore aspect ratio st peter sandstone which has a compressional velocity that is 17 higher than the predicted value the equation is insensitive to the chemical compostion of the dominant clay mineral and apparently insensitive to the location of the clay grains with respect to the mineral framework e g in free pore space or in contact zones between mineral grains of lower compressibilities

the relationships between the velocities attenuations and petrophysical properties of reservoir sedimentary rocks1 the authors have measured the velocities and attenuations of compressional and shear waves in 29 water saturated samples of sandstones and shales at a confining pressure of 60 mpa and at frequencies of about 0 85 mhz the measurements were made using a pulse echo method in which the samples diameter 5 cm length 1 5 cm to 2 5 cm were placed between perspex buffer rods inside a high pressure cell the velocity of each seismic wave was determined from the travel time difference of equivalent phase points corrected for diffraction effects of the signals reflected from the top and from the base of each samples attenuation was determined in a similar way by comparison of the diffraction corrected amplitudes of the signals the attenuation data are presented as quality factors q sub p and q sub s for compressional and shear waves respectively and shear waves respectively the results show that qs is strongly correlated with v sub s that q sub p is weakly correlated with v sub p and that q sub p is strongly correlated with q sub s center dot q sub p is strongly dependent on the volume percentage of the assemblage of intra pore minerals whether they are clays or carbonates it is concluded that themore attenuation mechanism is due to the local fluid flow arising from the differential dilation of the solid rock frame and the intra pore mineral assemblage which is a results of their very different elastic moduli less

the high resolution holocene sea level curve for northwest germany global signals local effects or data artefacts a few years ago a new relative sea level curve for northwest germany was constructed for the entire german north sea coast it is characterised by several suspected sea level fluctuations to test this curve for local effects it was broken down into five relative sea level curves representative for five coastal sections the relative sea level curves were corrected for tidal effects and also a rough first correction for compaction was applied the five curves all differ from the original curve and from each other most of the suspected sea level fluctuations in the original curve cannot be supported and are discussed as data artefacts or local effects around ad 800 1000 all curves show stagnation or drop of sea level thus this signal is discussed as of over regional stratigraphic meaning this study is a first step 1 to show that several curves are needed to demonstrate the holocene sea level history of such a big area as the entire german north sea coast and 2 to establish reliable relative sea level curves for the german north sea coast further research is necessary to apply detailed corrections especially with respect to compaction prone data and to improve the individual curves

onshore quaternary geological surveys in the 21st century a perspective from the british geological survey abstract at the turn of the century the british geological survey has embarked on a major programme to construct a 3 dimensional geological model of the uk the reassessment of methodologies used to investigate quaternary deposits and processes forms an important part of this programme surveys of user requirements indicate that the collation of new data and the generation of new output are needed to meet the diverse needs of society such as information on the geometry of sediment bodies their lithologies geotechnical properties and permeability the rockhead surface slope stability land susceptible to flooding coastal sediments contaminated land and artificial deposits these initiatives are driven by the recognition that the dynamic quaternary record reflecting the effects of recent climate and neotectonic change has both short and long term relevance to the use of information on the natural environment in which we live

application of indicator simulation to modelling the lithological properties of a complex confining layer abstract this paper describes a three dimensional simulation of the texture distribution of a complex confining layer indicators are used to characterize statistically the spatial variability of the different texture classes sequential indicator simulation is then used to generate equiprobable realisations of texture classes conditional on the textures found at the drilling sites by successively assigning values for conductivities and porosities to the simulated texture classes fields of conductivities and porosities can be obtained these can in turn be used as input for a groundwater model in a monte carlo analysis a case study is presented to demonstrate the application of sequential indicator simulation to the stochastic modelling of the texture distribution of a complex confining layer in the netherlands the results are validated using the data from a lithological cross section with a very small borehole spacing

middle and late holocene avulsion history of the river rhine rhine meuse delta netherlands at present little evidence is available on avulsion rates avulsion frequencies and interavulsion periods of aggrading fluvial systems over time scales of millenia the large number of high quality 14c ages from the holocene rhine meuse delta central netherlands enables a detailed assessment of such avulsion parameters and an evaluation of the factors controlling avulsion frequency 14c histogram analysis indicates that instantaneous avulsion coexistence of successive channel belts for less than a few centuries has dominated in this area interavulsion periods were typically 1000 yr although values of 500 or 5000 yr have also been found avulsion frequency was especially large prior to 4300 cal yr b p indicating a strong control by aggradation rate in turn controlled by sea level rise in addition periods with high avulsion frequency appear to correlate with time intervals characterized by large scale transgressive tendencies the time interval with the largest number of coexisting distributaries corresponds to the period with dominance of anastomosing fluvial style

experimental comparison between spectral ratio and rise time techniques for attenuation measurement two techniques for the measurement of attenuation spectral ratio and rise time techniques were tested and compared in the laboratory the spectral ratio technique proved to be reliable and easy to implement for intermediate values 5 50 and high attenuations the spectral ratio technique is inaccurate calculating the rise time on simulated signals we found a relation between rise time and the ratio travel time to quality factor t q which could be approximated in intervals by the linear relation c t q the constants and c depend on the absolute value of t q and on the initial source signal the rise time technique performed on the first quarter period of the signal enables high attenuations q 5 to be measured the determination of the relation between and t q is possible if one knows the initial source we theoretically approximate this relation through a simulation using a realistic propagation model with laboratory measurements made on fontainebleau sandstone we show that the rise time technique using the theoretical relation t q gives comparable values of q to those obtained from the spectral ratio technique in borehole seismics where it is often difficult to remove undesired signals the rise time technique applied with the right t q relation is the best method to use

coupled pattern analysis of sea surface temperature and topex poseidon sea surface height abstract though thermal effects dominate steric changes in sea level the long period contribution of thermal expansion to sea level is uncertain nerem et al found that a global map of sea surface temperature sst trends and a corresponding map of topex poseidon derived sea surface height ssh trends were strongly correlated this result is explored with a coupled pattern analysis cpa between five years of global sst and ssh which allows for matching of modes of common temporal variability the dominant mode found is an annual cycle that accounts for nearly all 95 3 of the covariance between the fields and has a strong sst ssh spatial correlation 0 68 the spatial correlation is strong in both the atlantic 0 80 and the pacific 0 70 good temporal and spatial agreement between the ssh and sst fields for the primary seasonal mode suggests that a robust regression between fields may have some physical significance with respect to thermal expansion and that the regression coefficient might be

enso like interdecadal variability 1900 93 a number of recent studies have reported an enso like eof mode in the global sea surface temperature sst field whose time variability is marked by an abrupt change toward a warmer tropical eastern pacific and a colder extratropical central north pacific in 1976 77 the present study compares this pattern with the structure of the interannual variability associated with the enso cycle and documents its time history back to 1900 the analysis is primarily based on the leading eofs of the sst anomaly and anomaly deviation fields in various domains and the associated expansion coefficient or principal component time series which are used to construct global regression maps of sst sea level pressure slp and a number of related variables the use of anomaly deviations i e departures of local sst anomalies from the concurrent global mean sst anomaly reduces the influence of global mean sst trends upon the structure of the eofs and their expansion coefficient time series an important auxiliary time series used in this study is a southern oscillation index based on marine surface observations by means of several different analysis techniques the time variability of the leading eof of the global sst field is separated into two components one identified with the enso cycle related variability on the interannual timescale and the other a linearly independent residual comprising all the interdecadal variability in the record the two components exhibit rather similar spatial signatures in the global sst slp and wind stress fields the sst signature in the residual variability is less equatorially confined in the eastern pacific and it is relatively more prominent over the extratropical north pacific the corresponding slp signature is also stronger over the extratropical north pacific and its counterpart in the cold season 500 mb height field more closely resembles the pna pattern the amplitude time series of the enso like pattern in the residual variability reflects the above mentioned shift in 1976 77 as well as a number of other prominent features including a shift of opposite polarity during the 1940s

total engineering geology approach applied to motorway construction and widening in the netherlands part ii pilot site in tidal deposits the total engineering geology approach is applied to a roadway pilot project in the tidal deposits of the western netherlands its benefit as compared to the conventional geotechnical site investigation is demonstrated combining laser scanner altimetry data that is readily available to low cost gem 2 electromagnetic surveys allows for the refinement of the local geological model small and large scale heterogeneities have been detected in this study their existence has been confirmed by a line of closely spaced cpts on the basis of laser altimetry and gem 2 signature the identified heterogeneities are classified only a limited set of heterogeneities representative of the different classes requires a further detailed investigation aspects of feasibility accuracy and cost effectiveness have a need for further research

the streif classification system a tribute to an alternative system for organising and mapping holocene coastal deposits the classification system for organising and mapping holocene coastal deposits as introduced by streif is highlighted with respect to mapping requirements apart from the requirements such as a user friendly legend and map the linkage of the classification system with the history of deposition is demonstrated for the tide dominated lowlands of the southern north sea and english channel the linkage becomes obvious when considering the effect of the changes in the rate of relative sea level rise the difficulties that surrounded the lithostratigraphy of holocene coastal deposits and the principles of the classification system which eventually made an end to the well known and long standing debate about the lithostratigraphy are briefly recalled

sea surface temperature and sea surface height variability in the north pacific ocean from 1993 to 1999 1 correlations between advanced very high resolution radiometer pathfinder sea surface temperature sst and topex sea surface height ssh anomalies are calculated for the 7 year period 1993 1999 in the equatorial and north pacific these correlations provide measures of ssh and sst covariability and are obtained using an empirical orthogonal function analysis separately on the two fields and a singular value decomposition svd method on both fields simultaneously these correlations reveal distinct sst ssh states a warm elevated period from january 1993 to december 1994 a cooler lower phase spanning january 1995 through december 1996 and the strongly variable el nino southern oscillation enso period spanning 1997 1999 the relationships between these sst ssh states and the dominant interannual and interdecadal modes of pacific variability are investigated through correlations with indices for the southern oscillation pacific north american pna pattern and pacific decadal oscillation pdo when including the tropics significant correlations between the first svd mode of the sst ssh covariability and the interannual enso pattern and interdecadal pdo pattern are evident restricting the focus to the extratropical north pacific reveals significant correlations with only the interdecadal pdo pattern while the first mode reveals connections to the enso and pdo patterns the second svd mode indicates significant correlations to the pna pattern for both the tropical and extratropical pacific

successive cracking steps of a limestone highlighted by ultrasonic wave propagation a number of laboratory tests uniaxial triaxial and hydrostatic have been conducted on a dry porous limestone a conceptual model is proposed to correlate deformation and damage fields including acoustic emission activity with the variation of ultrasonic velocities quality factors and energies as measures of attenuation this correlation is presented in a stress deviator versus confining pressure diagram in this way the successive steps occurring in the damage process of this rock are well described in particular the quality factor of s waves distinguishes clearly the onset of the initially stable cracking while the velocity of s waves and strain measurements are sensitive to dilatancy which appears later in the damage process of the limestone studied

is climate variability over the north pacific a linear response to enso abstract indices of the dominant spatial patterns of wintertime northern hemisphere 500 mb height and north pacific sea surface temperature are strongly correlated with one another on interannual and interdecadal timescales and both am correlated with indices of the el nin southern oscillation one possible interpretation of these relationships is that the tropical sst anomalies associated with enso force the atmospheric circulation over the north pacific and these atmospheric anomalies in turn give rise to the observed sst anomalies over the extratropical north pacific in this study linear relationships between enso and extratropical variables are examined in two different ways first the component of the observed extratropical variability that is linearly dependent upon enso is removed the dominant spatial patterns in the residual variability of 500 mb height and sst anomalies over the north pacific are shown to be similar to their counterparts in the total fields and remain strongly coupled on

archaeology a major tool in the reconstruction of the coastal evolution of westergo northern netherlands abstract westergo is the name of the coastal area in the northern netherlands between the former tidal systems of marne and middelzee the area silted up and changed into a salt marsh area during the subatlantic 1000 bc 500 ad the history of seaward migration of the salt marshes in the area has been reconstructed with the help of the archaeologically dated settlements on dwelling mounds terps terps were constructed on the salt marshes when the process of silting had reached the stage of the middle marsh this zone is flooded less frequently than ca 50 days per year the construction of terps during the middle stage of marsh development is indicated by the thickness of the salt marsh deposits on which terps were built and by the diatoms found in these marsh deposits the oldest phase of terp settlement on the marshes of westergo is dated between the late bronze age and early iron age ca 600 bc and is found in the southern part of westergo the old land during the next period 500 bc 500 ad the funnel shaped tidal basin in the northern part silted up to the supratidal level the middle marsh zone in the funnel shaped basin expanded during this period 1000 years by ca 5 km at the western and eastern sides of the basin and by ca 10 km in the central part this implies a mean marsh extension in this former tidal basin of ca 5 10 m per year in this paper a reappraisal of the nature and genesis of the salt marsh ridges of the northern netherlands is presented

towards an integrated land sea stratigraphy of the netherlands abstract the classification of rocks and sediments may be based on many types of stratigraphy e g litho bio seismo chrono chemostratigraphy and others the boundaries of the various types of stratigraphy need not at all or seldom coincide it is especially this last consideration that may cause problems since this discrepancy in boundaries is very difficult to understand for those not professionally trained as geologists since tno nitg as the dutch geological survey is an organisation for applied geosciences it is necessary that full notice is taken of this problem a complete revision of the existing late tertiary and quaternary lithostratigraphy of the onshore part of the netherlands which was a mixture of various types of stratigraphies was undertaken starting in 1997 at the same time the opportunity was taken to integrate this new scheme with the two other operational stratigraphies used by tno nitg important solutions in resolving some of the integration problems are outlined an example of the relation between some of the newly established lithostratigraphic units with some of the seismostratigraphic ones used in the offshore part of the netherlands is given finally an example of the implications of the new approach for the existing geological model is presented

application of autocorrelation analysis for interpreting acoustic emission in rock the statistical properties of acoustic emission from rock samples were studied as a function of applied uniaxial load it was found that the parameters of the autocorrelation function of the acoustic emission event series change significantly near failure an increase in the values of the autocorrelation coefficients and a tendency to a linear decrease with time were observed we propose that the increasing autocorrelation of the acoustic emission series is an evidence of the increased affect that the individual acoustic emission sources have on one another this mutual effect of acoustic events arises as a result of the redistribution of stress in the sample during the fracturing process at higher loads more than 95 of ultimate strength the results support the possibility of using autocorrelation analysis as a failure warning sign or even to predict the sample s total failure different rock materials and various loading patterns were used to generalise the results obtained

factors controlling the holocene avulsion history of the rhine meuse delta the netherlands abstract the avulsion history of the holocene rhine meuse delta the netherlands was reconstructed on a timescale of millenia using detailed paleogeographic maps based on approximately 200 000 lithological borehole descriptions over 1150 14c ages and 36 000 archaeological artifacts gradient lines were constructed for all channel belts these allowed determination of gradients paleo flow direction relative age of channel belts and time correlation of undated channel belt fragments avulsion sites were inferred from the paleogeographic reconstruction at least 91 avulsions occurred over the past 10 000 years of which 82 could be dated with an accuracy of 200 14c years the location and shifting of holocene avulsion sites in the rhine meuse delta in space and time are related to 1 relative sealevel rise in the early holocene avulsions could not take place because rivers were still incised around 7500 yr bp avulsions occurred in the western part of the present delta as a result of backfilling of the late weichselian valley between 7500 and 3700 yr bp the zone where avulsions occurred shifted inland as a result of relative sealevel rise 2 neotectonics between 4900 and 1700 yr bp the location of avulsion sites seems to have been influenced by neotectonic movements of the upthrown peel horst four out of six avulsion nodes in the rhine meuse delta were located in the peel horst fault zones 3 increased discharge and or within channel sedimentation from 2800 until about 1500 yr bp avulsion sites were located all over the delta during this time the number of channels was high and avulsion frequency reached a maximum at a time when aggradation rate decreased with a reduction in the rate of sealevel rise after 2000 yr bp meander wavelength of alluvial channels increased considerably the increased meander wavelength and the high avulsion frequency are attributed to increased bankfull discharge or within channel sedimentation leading to channel widening or both 4 human influence between 1000 and 650 yr bp all the rivers were embanked and avulsions could no longer take place the few that occurred were induced by humans

holocene evolution of the coast of holland abstract the holocene evolution of the coast of holland was controlled by the complex interaction of such diverse parameters as wave and tidal climate the rate of sea level rise and the morphology of the pre transgressional surface the latter in combination with the rate of sea level rise mainly determines the location of sediments sources and sinks while the hydrodynamic parameters mainly determine the rate and direction of sediment transport in the early holocene the low sea level in the shallow southern north sea strongly affected wave climate and tidal regime however the barrier and back barrier sedimentary record since 5000 14c yrs b p gives us no reason to assume major changes in these parameters since then so we conclude that breaks in barrier development are due to variations in rate of sea level rise inl combination with the morphology of the pre transgressional surface the transformation from an open tide dominated to a closed wave dominated coast which occurred in the subboreal period and the concomitant change in barrier movement from transgressive to regressive around 5000 yrs b p are the main events in the development of the coast of holland up to the middle ages the morphology of the pre transgressional surface gives a shoreline in the late atlantic which consists of two protruding headlands separated by a large tidal basin the southern headland is the alluvial plain of the rhine and the meuse the northern headland constitutes the moraines of the texel high the tidal basin in between is connected to the north sea by a large number of inlets the rate of sea level rise at that time 1 m century outran the supply of sediment to the tidal basin after 6000 yrs b p the rate of sea level rise decreased gradually whereas the rate of sediment supply remained constant this led to a gradual decrease in the tidal prisms of the inlets as the tidal basin was filled in with sediment shortly before 5000 yrs b p the first channels silted up and closed the last tidal channel disappeared around 3300 yrs b p leaving two inlets along the coast which were both connected to the river rhine the closure of the first inlets occurred at the same time as the barrier began prograding because 1 the rate of sea level rise diminished considerably 2 not all the sand supplied by longshore and cross shore transport disappeared into the tidal basin but instead could be used for barrier progradation and 3 ebb tidal deltas of the closed inlets provided major sand sources the prograding barrier sequence enclosed between the two headlands roughly forms a closed system using the relationships between tidal prism cross sectional area of inlets and volume of the ebb tidal delta and the results of modelling of longshore transport along the subboreal coast under present day wave conditions a simple sand budget for the coast of holland is given which shows that a large part of the sand now stored in the barrier sequence was obtained by cross shore transport from the north sea

late quaternary sea level change and isostatic and tectonic land movements along the belgian dutch north sea coast geological data and model results early and middle holocene sea level data from belgium plot ca 2 m above data from the western netherlands reflecting differential tectonic and isostatic movements the total uplift rate of belgium relative to the western netherlands decays gradually from 0 66 m kyr 1 at 7500 cal yr bp to less than 0 25 m kyr 1 since 5000 cal yr bp the tectonic component of this relative movement inferred from eemian sea level data is in the order of 0 06 to 0 16 m kyr 1 the isostatic component of the uplift is related to the last phase of the collapse of a peripheral bulge under the netherlands and the dutch and german sectors of the north sea and to hydroisostatic subsidence of the north sea basin caused by water loading as sea level rose comparisons with isostatic rebound models show that they predict well the holocene isostatic movement between belgium and the western netherlands and that the predictions are improved when the tectonic component is removed from the observations preliminary evaluation of sea level data from the dutch sector of the north sea shows that glacio hydroisostatic subsidence relative to belgium was significantly greater than for the western netherlands coastal area and spatially highly variable copyright 2002 john wiley sons ltd