desert agricultural systems at eba jawa jordan integrating archaeological and paleoenvironmental records located in the arid basalt desert of northeastern jordan the settlement of jawa is by far the largest and best preserved archaeological site in the region the early bronze age eba settlement phase of jawa 3500 3000 bce is characterized by a highly sophisticated water storage system made of a series of pools dams and canals in addition recent archaeological and geoarchaeological surveys have uncovered agricultural terrace systems in the nearby vicinity in this study four of these runoff terrace systems were investigated by detailed mapping additionally thirteen sediment profiles from inside and outside the terrace systems were recorded and sampled the examined samples were analyzed for bulk chemistry texture phytoliths diatoms and dung spherulites to supply information on the environmental and depositional conditions the terrace systems were dated using optically stimulated luminescence osl ancient terrace agriculture was practiced on slopes small plateaus and valleys close to jawa through the use of surface canals which collected and diverted floodwater from nearby wadis or runoff from adjacent slopes the terraced fields were usually arranged in cascades and comprised a system of risers canals and spillways the terrace fills investigated yield osl ages of around 3300 bce indicating that the terraces were constructed in the early bronze age the terrace fill sequences are composed of mixed unstratified fine sediments of local origin reflecting low energy fluvial deposition regimes the phytolith record is dominated by pooid grasses that include the most common near eastern cereals such as wheat and barley increased phytolith concentrations in terrace fill sediments as compared to samples from non terrace deposits nearby suggest increased plant growth and water availability within the terraces whether the terrace systems were used for growing food crops only or whether they were additionally used for grazing cannot be ascertained overall quantitative phytolith analyses in arid environments are well suited to investigate temporal and spatial distributions of plant microfossil concentrations and their relation to human activity or paleoenvironmental conditions

direct measurements of ocean surface velocity from space interpretation and validation the median doppler shift of radar echoes is analyzed in measurements by envisat s advanced synthetic aperture radar asar over the ocean this doppler centroid differs from a predicted signal based on the predicted motion of the satellite and earth this anomaly converted to a surface doppler velocity u d appears to be of geophysical origin two wide swath images over the gulf stream around cape hatteras suggest that u d contains high resolution information on surface currents while on a global scale u d is found to vary with the wind speed in the range direction a simple quantitative forward model is proposed based on a practical two scale decomposition of the surface geometry and kinematics the model represents the effect of the wind through the wave spectrum and gives u d u 10 u c with u 10 and u c as the 10 m wind speed and quasi eulerian current in the line of sight of the radar projected on the sea surface respectively and as a coefficient function of the wind speed wave development and radar geometry it is found that for an incidence angle of 23 0 3 for moderate winds and fully developed seas this model is validated with a global data set of asar wave mode observations with colocated model winds acquired over the global ocean during the years 2003 and 2004 the doppler signal therefore provides the signed parameter u d that can be used to reduce the wind direction ambiguity in the inversion of high resolution wind fields from sar imagery a qualitative validation of current effects is shown for the english channel where tidal currents dominate thus it should be possible to combine this previously ignored geophysical doppler signal with traditional information on sea surface roughness in order to provide very high resolution wind and current fields

phytolith rich layers from the late bronze and iron ages at tel dor israel mode of formation and archaeological significance the presence of many phytolith rich layers in late bronze and iron age deposits at tel dor israel are indicative of specific locations where plants were concentrated detailed studies of six of these phytolith rich layers and associated sediments from tel dor show that the phytoliths were derived mainly from wild and domestic grasses the most common domestic grass was the cereal triticum aestivum bread wheat three of these layers have a microlaminated microstructure associated dung spherulites and phosphate nodules characteristics that all point to the phytolith rich layers having formed from dung in animal enclosures in two of the layers the microlaminated structure is absent while dung spherulites and phosphate nodules are present suggesting that these too originate from dung that was not deposited in an enclosure the sixth layer is microlaminated but does not contain spherulites we thus cannot suggest a parsimonious explanation of its observed properties concentrations of burnt phytoliths are present in three locations implying that dung was either burnt in situ or the ashes from burnt dung were redeposited the transformation of dung accumulations into phytolith rich layers involves a loss of organic material and hence a significant reduction in sediment volume which is clearly apparent in the stratigraphy of some of the locations examined the volume reduction can be observed in the macrostratigraphy and has important implications with regard to macrostratigraphic interpretation the presence of abundant phytolith rich layers on the tell has significant implications for the concept of urbanism during these periods 2007 elsevier ltd all rights reserved

estimating advective near surface currents from ocean color satellite images abstract improved maximum cross correlation mcc techniques are used to retrieve ocean surface currents from the sequential ocean color imagery provided by multiple newer generations of satellite sensors on hourly scales in the yellow sea and the u s east and gulf coasts the mcc calculation is validated in a series of bio optical forecasting biocast experiments with predetermined synthetic velocities and its products are evaluated by examining the errors and biases with respect to the high frequency radar hfradar measurements the root mean square rms errors in our best current products derived from the overlap of satellite sensor swath between the viirs sequential orbits are less than 0 17 m s 1 in the evaluation area outside of the chesapeake bay the most accurate current products are those derived from the imagery data of r rs 551 b b 551 and c 551 while the image sequences of b b 551 and z eu lee are identified as the most suited products for the retrieval of currents because of their best production capacities of valid velocity vectors mechanisms between the advective processes and the dynamic changes of bio optical properties are discussed regarding the performances of various color products on the retrieval of currents similarities of velocity distribution in the retrieved vector arrays are collected across different mcc products derived from ocean color datasets that are of different types and derived from different spectral channels of satellite overpasses the inter product similarities themselves can be used to characterize the near surface advection as well and usually have smaller errors than each of the individual mcc currents moreover efforts are also under way to improve the ocean color derived currents by merging several of the mcc products with similarities to increase the total spatial coverage this study not only seeks the image derived products best representing the sea surface current structures in coastal areas but also exploits how these currents can be improved or optimized to support the ocean forecasts

computing coastal ocean surface currents from infrared and ocean color satellite imagery many previous studies have demonstrated the viability of estimating advective ocean surface currents from sequential infrared satellite imagery using the maximum cross correlation mcc technique when applied to 1 1 km resolution advanced very high resolution radiometer avhrr thermal infrared imagery applied only to infrared imagery cloud cover and undesirable viewing conditions gaps in satellite data and edge of scan distortions limit the spatial and temporal coverage of the resulting velocity fields in addition mcc currents are limited to those represented by the displacements of thermal surface patterns and hence isothermal flow is not detected by the mcc method the possibility of supplementing mcc currents derived from thermal avhrr imagery was examined with currents calculated from 1 1 km resolution moderate resolution imaging spectroradiometer modis and sea viewing wide field of view sensor seawifs ocean color imagery which often have spatial patterns complementary to the thermal infrared patterns statistical comparisons are carried out between yearlong collections of thermal and ocean color derived mcc velocities for the central california current it is found that the image surface patterns and resulting mcc velocities complement one another to reduce the effects of poor viewing conditions and isothermal flow the two velocity products are found to agree quite well with a mean correlation of 0 74 a mean rms difference of 7 4 cm s and a mean bias less than 2 cm s which is considerably smaller than the established absolute error of the mcc method merging the thermal and ocean color mcc velocity fields increases the spatial coverage by approximately 25 for this specific case study

earthquake location accuracies in norway based on a comparison between local and regional networks adetailedstudies of the low to intermediate seismicity in two coastal regions of norway have been used in a comparison between earthquake locations from local high precision networks on the one side and locations using a sparse regional array network on the other side to this end a reference set of 32 low magnitude earthquakes have been located using two local temporary networks in northern and western norway with estimated epicenter accuracies better than 5 and 10 km respectively comparisons are made between the local network solutions and the norsar generalized beamforming gbf system which provides automatic phase association and location estimates using the fennoscandian regional array network the median automatic gbf location error is of the order of 20 30 km when four or more arrays detect the event increasing to about 80 100 km when only two arrays are available and the automatic gbf bulletin is essentially complete down to magnitude ml 2 0 most of the mislocation vectors of the norsar gbf solutions are oriented perpendicular to the norwegian coast and with a tendency to pull the location in a southeasternly direction the gbf performance is clearly better both in terms of accuracy and completeness than the performance of the automatic bulletin of the prototype international data center pidc which uses data from essentially the same network the analyst reviewed norsar and pidc bulletins show not unexpectedly an improvement in location accuracy compared to the automatic solutions and appear to be of similar quality for the few common events with an average mislocation of about 20 km the norsar reviewed bulletin is more complete at low magnitudes compared to pidc and there appears to be a potential for significant improvements in the pidc processing of small seismic events in this region

seismic activity inferred crustal stresses and seismotectonics in the rana region northern norway abstract the seismotectonic significance of the rana region is known both from the fact that this was the location of the largest known earthquake in fennoscandia in recent times the m s 5 8 6 2 earthquake of august 31 1819 and from its relatively high constant seismic activity also in the 20th century in order to study this region in more detail a local seismic network has been in operation there since july 1997 as part of the neonor neotectonics in norway project the network was primarily designed to detect possible activity on the basmoen fault which runs 50 km subparallel to the rana fjord and which shows signs of likely post glacial activity the results have revealed a quite complex spatio temporal distribution of seismic activity and has also shown no activity on the basmoen fault itself during the first 18 months of operation july 1997 january 1999 the network has detected 373 locatable seismic events of which 267 were local earthquakes most of these earthquakes occurred in five groups in the western parts of the network all five groups had similar nnw esw trends in epicenter locations and all have shallow foci 2 12 km similar to what has also been found earlier for other concentrated earthquake zones in northern norway and the magnitude range is between m l 0 1 and 2 8 earthquake focal mechanism solutions within the network reveal a predominance for normal faulting with the tensional stress axis perpendicular do the coastline implying an unusual coast parallel orientation of the principal horizontal compressive stress the earthquakes occur in a region of maximum post glacial uplift gradients which supports deglaciation flexure as a viable explanation for these earthquakes a certain influence from more local factors however tied in general to crustal in homogeneities cannot be ruled out

blame it on the goats desertification in the near east during the holocene the degree to which desertification during the holocene resulted from climatic deterioration or alternatively from overgrazing has puzzled quaternary scientists in many arid regions of the world i

sar observation and numerical modeling of tidal current wakes at the east china sea offshore wind farm a terrasar x ts x synthetic aperture radar sar image acquired at the east china sea offshore wind farm presents distinct wakes at a kilometer scale on the lee of the wind turbines the presumption was that these wakes were caused by wind movement around turbine blades however wind analysis using spaceborne radiometer data numerical weather prediction and in situ measurements suggest that the prevailing wind direction did not align with the wakes by analyzing measurement at the tidal gauge station and modeling of the tidal current field these trailing wakes are interpreted to have formed when a strong tidal current impinged on the cylindrical monopiles of the wind turbines a numerical simulation was further conducted to reproduce the tidal current wake under such conditions comparison of the simulated surface velocity in the wake region with the ts x sea surface backscatter intensity shows a similar trend consequently turbulence intensity t i of the tidal current wakes over multiple piles is studied using the ts x observation it is found that the t i has a logarithmic relation with distance furthermore another case study showing wakes due to wind movement around turbine blades is presented to discuss the differences in the tidal current wakes and wind turbine wakes the conclusion is drawn that small scale wakes formed by interaction of the tidal current and the turbine piles could be also imaged by sar when certain conditions are satisfied the study is anticipated to draw more attentions to the impacts of offshore wind foundations on local hydrodynamic field

computing ocean surface currents over the coastal california current system using 30 min lag sequential sar images as compared with conventional methods for measuring ocean surface currents spaceborne synthetic aperture radar sar offers cloud penetrating ocean current observation capability at high spatial resolution while some studies have shown the potential of sar for studying ocean surface currents through feature tracking they have only analyzed a few images to demonstrate the basic measurement technique and no concise general technique has been developed this paper shows the application of the maximum cross correlation mcc method to generate ocean surface currents from nearly two years of available sequential spaceborne c band sar imagery from the envisat asar and ers 2 advanced microwave instrument sar sensors over the coastal california current system the data processing strategies are discussed in detail and results are compared with hf radar measured currents one dimensional wavenumber spectra of the sar derived surface currents agree with the k 2 power law as predicted by submesoscale resolution models comparisons with hf radar currents show encouraging results with mcc sar vectors oriented slightly counterclockwise relative to hf radar vectors mcc sar surface currents are found to have larger magnitudes than hf radar currents approx 11 cm s which may be due to the fact that sar penetrates only a few centimeters into the ocean surface whereas hf radar currents are averaged over the top 1 m of the ocean surface the larger part of this magnitude difference is contained in the along shore component which can be attributed to higher hf radar accuracy in the direct radial cross shore measurements as compared with along shore components derived from multiple cross shore radial measurements

a micromorphological view through a namaqualand termitaria heuweltjie a mima like mound heuweltjies occur throughout namaqualand and the western and southern cape coasts broad low relief termitaria of the harvester termite microhodotermes viator which show different vegetation patterns to the surrounding soils distinguishable even in satellite images there is a direct relationship between soil hardpan occurrence and the heuweltjies characteristically in the semi arid areas the hardpans grade outwards from a central sepiolitic petrocalcic horizon laterally through petro sepiolitic palygorskitic variable in the degree of cementation to the petroduric horizon on the edges in a landscape in which these hardpans are otherwise absent the aim of the study was to investigate the genesis of these hardpans associated with the heuweltjie mound with a particular focus on the build up of calcite and sepiolite the micromorphological study examined a transect through a representative sepiolite bearing heuweltjie on the coast near the olifants river mouth and revealed evidence of termite activity in the central petro calcic part of the mound this concentration of calcite and mg rich clay in the centre can be explained by termite foraging as the regionally characteristic ca and mg rich foliage is moved into the centre of the mound facilitating the precipitation of calcite and sepiolite as bacterial decomposition and subsequent leaching modify the soil solution in the mound the increase in coarse fine ratio from the centre outward showed that accumulation of calcite and sepiolite displaced the original sand matrix by a greater degree than the silica accumulation consistent with the topographically raised surface in the centre limpid yellow low birefringent nodules some with pseudo negative uniaxial interference figures showed a fibrous nature under esem and their low ca and molar mg si ratios of 0 64 to 0 68 esem edx were consistent with sepiolite the presence of the sepiolite with its mg rich composition and hydrophilic character together with organic acids generated from the vegetation collected by the termites is considered to be an explanation for the formation of ooids radial calcite crystals associated with a core of sepiolite colourless non calcareous pseudo uniaxial negative spherulites were present in fresh termite excrement from an active heuweltjie near stellenbosch these were either produced in the termite gut itself or had been ingested along with herbivore dung by the termites the presence of faecal spherulites in termite excrement is significant since it shows that faecal spherulites can be distributed over a wider area than that directly associated with mammalian herbivores

origins of carbonate spherulites implications for brazilian aptian pre salt reservoir abstract spherulites spherical to elliptical allochems composed of crystals radiating from a common core investigated from a variety of depositional settings e g hot springs ambient water temperature geyser tufa and caliche are all composed of a fine grained nucleus made up of carbonate encrusted bacterial bodies biofilms and or eps and surrounded by a cortex of radiating crystals of either aragonite or calcite the microbes and their by products in the nucleus induced the precipitation of carbonate overcoming the inhibition to initiate crystal formation the enveloping radiating crystals comprising aragonitic cortices tended to grow abiotically producing well formed euhedral crystals with a paucity of included bacterial fossils whereas those cortical crystals made up of calcite commonly contained bacterial fossils indicating that the bacterial colonies contributed to the calcitic cortical crystal precipitation similar spherulites form a thick widespread accumulation in the aptian pre salt lacustrine deposits in the campos basin offshore brazil as with the travertine tufa and caliche spherulites the pre salt spherulites most likely initiated carbonate precipitation around bacterial colonies and or their bioproducts probably while afloat in a lacustrine water column before settling to the water sediment interface absence of inter spherulite sediment and the spherulite to spherulite compaction indicate that cortical crystal growth continued while the spherulites were at the sediment water interface rather than displacively within a sediment

measurement of surface currents using sequential synthetic aperture radar images of slick patterns near the edge of the gulf stream two dimensional surface currents are estimated over an area of 100 km2 near the inshore edge of the gulf stream by correlating the surface slick patterns observed on two synthetic aperture radar sar images collected about 20 min apart the currents obtained from this analysis are found to agree well with shipboard acoustic doppler current profiler adcp measurements at 10 to 20 m depths the orientations of the long linear slicks observed in this region differ from the mean current direction by about 16 but coincide with the direction of maximum radial deformation or strain as calculated from the observed current field the calculated current gradients indicate a mean surface convergence of about 2 10 5 s 1 and a cyclonic vorticity of about 1 10 4 s 1 values which fall within the range of previous estimates in the study area these results suggest that slick patterns may be used to infer surface current magnitude and direction from a time sequence of sar images but that care must be exercised in inferring current directions from the orientations of slick patterns within a single image

seismotectonics of the norwegian continental margin the norwegian continental margin and surrounding areas are seismically less active than some other passive margins worldwide indicating a potential earthquake deficit the adjacent oceanic crust is mostly aseismic except for parts of the lofoten and norway basins which have experienced rapid deposition of glacial sediments the excess load has enhanced the local stress field and in turn the seismic activity the marginal highs along the continent ocean transition and the part of the more and voring basins which experienced crustal extension prior to the early tertiary breakup are practically aseismic this region is also underlain by high velocity lower crust emplaced during breakup suggesting crustal strengthening which also may increase the return periods for the largest events farther landward a spatial correlation of seismic activity and the glacial sediment wedge suggests a causal relationship expressed through preferential rejuvenation of late jurassic early cretaceous faults the locally high seismic activity in the coastal region occurs in areas where the continental crust is relatively thick 25 30 km but still thinner than in the shield area farther east 45 50 km although stress relations are complex we suggest that increased stress due to appreciable postglacial rebound gradients in the coastal region may be a contributing factor while the stress field along the margin complies in general with the ridge push force we infer that regional and local stress enhancement factors are not only present in this region but also necessary for explaining the earthquake activity the relative importance of local stress sources is supported by several cases of 90 stress rotations relative to the ridge push direction the superposition of regional and local stress together with the existence of weakness zones and faults yields potentials for earthquakes primarily through structural reactivation

sea surface velocities in shallow seas extracted from sequential coastal zone color scanner satellite data sequential images of visible wavelength reflectance from channel 3 540 560 nm of the coastal zone color scanner czcs have been used for computing advective velocities in the eastern english channel using the maximum cross correlation technique the computation method known as matched filtering is widely used by meteorologists and has recently been applied by oceanographers to detect sea surface motion from satellite infrared images provided accurate coregistration of images is achieved by matching ground control points significant correlation is obtained when the technique is applied to czcs data and coherent velocity distributions are obtained for united kingdom shelf waters the residual circulation patterns for the english channel are found to be consistent with previous studies and recent observations

first analysis of terrasar x along track insar derived current fields we present the first analysis of surface current fields derived from terrasar x along track interferometric synthetic aperture radar along track insar ati data the images were acquired over the mouth of the elbe river germany during six satellite overpasses in spring and summer 2008 using the experimental aperture switching mode of terrasar x in this mode the phased array synthetic aperture radar sar antenna is split into two halves for receiving but in contrast to the dual receive antenna mode which uses two independent receivers in parallel a single receiver is multiplexed to process signals from the two antenna halves in an alternating manner at a doubled pulse repetition frequency the effective ati baseline is on the order of 0 8 m the sar ati raw data processing is described in another paper in this issue this paper focuses on the conversion of the basic interferograms into line of sight surface current fields which includes an elimination of ship signatures identification and correction as far as possible of imaging artifacts additional filtering and smoothing and a subtraction of contributions of wave motions to detected velocities according to a theoretical model we evaluate the quality of the results by comparison with current fields from a numerical flow model and with available in situ data the ati performance of terrasar x is found to be basically consistent with theoretical expectations after applying the same data processing algorithms to all six images mean differences between terrasar x derived currents and reference currents in our main test area range from 0 11 to 0 08 m s in five of the six cases with one outlier at 0 42 m s the spatial current variations within the terrasar x derived current fields are consistent with the model in three cases but unrealistically strong variations across the images are found in the other three cases we attribute this to shortcomings of our preliminary raw data processing algorithms which can probably be fixed after some more detailed analysis and testing the results obtained so far encourage us to believe that our internal performance goal of a typical current measuring accuracy of 0 1 m s at an effective spatial resolution better than 1 km can be met

the micromorphological identification of faecal spherulites from archaeological and modern materials abstract microscopic calcium carbonate spherulites from animal dung are now regularly found in archaeological micromorphology samples they have a particular set of morphological and optical characteristics including a fixed cross of extinction which is always pseudo uniaxial negative this paper gives details of these characteristics and provides methodologies for using them to distinguish faecal spherulites from similar materials e g coccoliths and related biominerals such as plant derived calcium oxalate druses and avian reptilian uric acid spheres simple predictions are made concerning the effect of thin section versus liquid mount preparations on maximum retardation diameter plots these are confirmed by the pattern of the real data but a discrepancy remains between the measured birefringence of the spherulite material and the expected birefringence from radial calcite using morse donnay s 1932 american journal of science 23 421 461 calculation possible reasons for this discrepancy are discussed

an objective method for computing advective surface velocities from sequential infrared satellite images using cross correlations between sequential infrared satellite images an objective technique is developed to compute advective sea surface velocities cross correlations are computed in 32 x 32 pixel search second image and 22 x 22 template first image windows from gradients of sea surface temperature computed from the satellite images velocity vectors computed from sequential images of the british columbia coastal ocean generally appear coherent and consistent with the seasonal surface current in the region during periods of strong wind forcing as indicated by maps of sea level pressure the image advective velocities are stronger and more coherent spatially and appear to cross surface temperature gradients when winds are weaker the advective velocities correspond better with the infrared temperature patterns suggesting the increased contribution of the geostrophic current to the surface flow velocities determined from coincident near surface drogued 5 10 m buoys positioned every half hour by internal loran c units in mid june show excellent agreement with the image advective velocities in addition conductivity temperature and depth ctd measurements taken during the buoy tracking confirm the homogeneity of the upper 10 m and ctd derived geostrophic currents are consistent with

subsistence practices in an arid environment a geoarchaeological investigation in an iron age site the negev highlands israel the negev highlands southern israel is an arid zone characterized by settlement oscillations one settlement peak occurred in the early iron age iia late 10th and early 9th centuries bc the most conspicuous structure in many sites of this period is an oval compound comprised of an internal courtyard surrounded by rooms two hypotheses for the function of these oval compounds are that they served as israelite fortresses which guarded the southern border and routes of the solomonic kingdom or that they represent local agro pastoral groups in order to gather more information regarding the subsistence practices conducted in these oval compounds we carried out a small scale excavation at the site of atar haroa we focused on sediment sampling and used several geoarchaeological as well as isotopic techniques in order to identify macroscopic and microscopic remains related to animal husbandry and crop agriculture the remains identified from the archaeological sediments were compared with modern reference materials collected from abandoned bedouin camps the excavation included two half rooms and several test pits in the courtyard of the oval compound featuring one iron age occupation level composed of gray sediments and relatively small amounts of pottery bones and macro botanical charred remains micromorphological mineralogical dung spherulite and isotopic analyses carried out on the gray occupational sediments from the rooms show that they originate from wood ash and dung both used as fuel similar analyses of the gray sediments in the courtyard show that they originate only from degraded livestock dung phytolith analyses show that the gray anthropogenic sediments have similar concentrations of phytoliths as in control yellowish sediments and in the dung of winter free grazing desert livestock and lichen grazing black dwarf bedouin goats phytoliths indicative of cereal crops are completely absent in the archaeological dung remains indicating that cereal crops were not processed by the site inhabitants based on ethnographic and archaeological parallels and on the presence of grinding stones and absence of sickle blades in the excavated rooms we infer that the inhabitants at the oval compound at atar haroa subsisted on livestock herding and bought or exchanged cereal grains our results support the hypothesis that the inhabitants at the oval compound at atar haroa were desert adapted pastoralists rather than garrisoned soldiers

seismicity and seismotectonics of norway and nearby continental shelf areas the earthquake activity of norway and nearby offshore areas is low to intermediate with few events above magnitude 5 recent significant improvements in instrumental coverage in parallel with a better utilization of older including historical data have shown that the seismicity in the south is predominantly confined to the coastal areas and to the viking graben while from the northern north sea to svalbard the earthquakes in a broad sense follow the continental margin fifty one focal mechanism solutions from these areas about half of them new reveal stress directions that clearly indicate a connection to the plate tectonic ridge push force at least for the areas at a minimum distance from the continental margin along the margin stress directions also indicate a possible connection to postglacial uplift as well as to lithospheric loading effects a dominance of normal faulting on the landward side and reverse faulting on the oceanic side agrees with this interpretation on a regional level the seismicity in these areas correlate quite well with geologic features such as grabens fault zones fault complexes fracture zones and the margin itself indicating that these structures act in a general sense as weakness zones in the presence of a regionally more stable stress field in the northern north sea however an area with quite anomalous stress orientations with strike slip faulting is found in a region transitional between normal and reverse faulting most of the earthquake foci are confined to the presumably brittle parts of the crust but many events are also located quite close to and on both sides of the moho discontinuity

micromorphology and formation of pedogenic ooids in calcic soils and petrocalcic horizons abstract ooids pisoids nodules concretions and a host of other terms are used to describe concentrically zoned pedogenic carbonate phyllosilicates silica and other minerals in calcic and petrocalcic horizons worldwide the pedogenic and paleoenvironmental significance of such features is not always easy to interpret because variations in size structure composition and soil geomorphic context have been used to infer distinct modes of genesis for features that appear similar using both optical and scanning electron microscopy petrocalcic soil samples from the jornada la mesa geomorphic surface in new mexico and the mormon mesa geomorphic surface in nevada were studied to reconsider the formation of pedogenic ooids in this paper ooids are 2 mm in diameter and have a range of internal morphologies ooids were especially common within features including clast pendant laminae pisoids and laminar horizons or laminar horizon caps we propose a possible new mode of ooid genesis suggesting that crystal growth can move ooids tiny incremental distances over time and that phyllosilicates are an important genetic component ooids are interpreted to form via 1 mineralization during the evaporation of solutions held by surface tension around mineral grains clasts or petrocalcic fragments with or without the presence of organic matter 2 hydration and plastic behavior of pervasive pedogenic fibrous phyllosilicates that co precipitate with pedogenic calcite and 3 tiny successive movements caused by the crystallization pressure of pedogenic carbonate and other minerals during soil solution evaporation spheroidal morphology is initially promoted by chemical precipitation from evaporating solutions around grains next crystallization pressures from the surrounding matrix displace grains non uniformly promoting stochastic contacts or knocking of ooids against one another and against the soil matrix over long time spans this micrometer scale episodic translocation and rotation in tandem with the plastic behavior of fibrous phyllosilicates enhances the spherical shape of ooids the model described here does not preclude possible biological contributions to ooid genesis nor refute the role of other processes in producing similar features in the same soil finally ooid size is limited by physical and hydrological thresholds pisoids as larger features are more complex and are more likely to involve erosion they do not form in the same manner as ooids this study has implications for paleoenvironmental interpretations of calcic and petrocalcic horizons and for the selection of pedogenic features for isotopic analysis

earthquake swarm in steigen northern norway an unusual example of intraplate seismicity on the first of january 1992 unusual earthquake activity started in steigen northern norway by 31 december 1992 a total of 207 events had been recorded in several pulses among these several events with magnitudes larger than 3 0 mc were also felt by the people the epicentral distribution of these events seems to suggest that they all are concentrated in a small region approximately 10 km in diameter in the brennvika bay 67 8 n 14 9 e between leinesfjorden in the north and nordfolda in the south the distribution of events in time is characteristic of a swarm in which no dear evidence of a mainshock aftershock sequence was observed macroseismic intensity surveys as well as synthetic modelling indicate shallow focal depths in the range 5 8 km based on a composite focal mechanism indicating an oblique slip fault striking ne with a normal component dipping nw combined with an observed ne trend in the epicentres and the focal depths these events correlate with a previously proposed fault zone along nordfolda the ne trend has been dominant in the area throughout geological time starting from the caledonian orogeny to the post caledonian basin developments as well as the post glacial and neotectonic structural features at present the deep seated structural anomaly underneath the lofoten ridge seems to be the major factor controlling the structural trends in the area the activity along the nordfolda fault zone could be related to this large scale structure although the causes of the stresses that would create the seismic activity are not very clear as there are several possible stress generating mechanisms involved such as post glacial uplift of the land masses the ridge push effect from mohn s ridge and vertical stresses generated by the sediment loading in the adjacent basins

earthen mound formation in the uruguayan lowlands south america micromorphological analyses of the pago lindo archaeological complex the stratigraphic excavation of the pago lindo archaeological complex in central eastern uruguay la plata basin helped to propose an alternative model for mound formation that expresses the intrinsic complexity of prehistoric earthen architecture this model known as the spatial temporal discontinuous model sees mound complexes as multi functional areas with diverse earth works occupied and abandoned intermittently since earthen mound sediments are homogeneous resemble natural soils and show evidences of intense bioturbation soil micromorphology was used to confirm refute and further investigate issues raised during field work related with the prime material used for mound construction detection of major episodes of mound building identification of activity areas and taphonomic processes in this paper we present the results of the micromorphological analyses of two different earth works from the pago lindo archaeological complex a mound and a micro relief analyses proved the recurrent use of surface horizons for mound and micro relief building throughout the entire period of site occupation it also demonstrated the difficulty in identifying discrete depositional episodes and occupation surfaces because of the intense bioturbation two activity areas where recognized a domestic hut built over a platform ca 1600 yrs bp and an area of plant residue accumulation over a platform raised almost 800 hundred year after the domestic hut the practice of cleaning the occupation surfaces was interpreted from the complete absence of bioarchaeological remains bones and micro charcoal the use of micromorphology as a complementary tool in the stratigraphic excavation of pago lindo unraveled evidences that corroborate a newly proposed model for mound growth

identification of pastoral sites using stable nitrogen and carbon isotopes from bulk sediment samples a case study in modern and archaeological pastoral settlements in kenya abstract the identification of pastoral sites in the east african archaeological record is problematic recently a method for the identification of degraded livestock enclosure sediments had been developed that takes into account the geoarchaeological indicators of micromorphology phytolith concentrations and the mineral assemblages this suite of indicators may not always be present in degraded livestock enclosure sediments this study presents an additional indicator by which degraded livestock enclosure sediments may be identified namely the isotopic composition of organic nitrogen measured on bulk sediment samples we studied a highly controlled ethnoarchaeological sequence of abandoned maasai livestock enclosure sediments sampled in rombo area southern kenya the results were compared to archaeological sediments from the elmenteitan pastoral neolithic site of sugenya southwestern kenya radiocarbon dated to ca 2000 bp uncalibrated the sediments from both sites were studied using all four types of analyses i e micromorphology mineralogy phytolith concentrations and stable carbon and nitrogen isotopic compositions on bulk sediment samples the results show that in abandoned livestock enclosure sediments of known ages a significant enrichment in the heavy nitrogen isotope 15 n occurs and that carbon isotopic compositions may be useful for differentiating cattle from caprine enclosures following their dietary preferences i e grazers vs browsers a similar pattern of 15 n enrichment is observed in sediments sampled within the site of sugenya while sediments sampled outside the site s perimeter are generally depleted in 15 n the micromorphological mineralogical and phytolith analyses support the conclusion that the sediments from within the site of sugenya represent degraded livestock enclosure sediments the carbon isotopic composition from the degraded dung deposits strongly suggests that livestock kept at sugenya were cattle overall this study presents new empirical data that can be used for the identification of livestock enclosures and shows that the isotopic signatures and geoarchaeological indicators can preserve for at least two millennia

interferometric radar measurement of ocean surface currents we describe a new method of measuring surface currents using an interferometric synthetic aperture radar an airborne implementation has been tested over the san francisco bay near the time of maximum tidal flow resulting in a map of the east west component of the current only the line of sight component of velocity is measured by this technique where the signal to noise ratio was strongest statistical fluctuations of less than 4 cm s 1 were observed for ocean patches of 60 60 m

mapping the agulhas current from space an assessment of asar surface current velocities 1 over 2 years of surface current information collected in the agulhas current region and derived from the doppler centroid anomalies of envisat s advanced synthetic aperture radar asar are examined the sources of errors and potential use of asar surface current velocities for oceanographic research are assessed asar surface current velocities are compared to surface drifter data and merged altimetry observations maps of sea surface temperature are used to establish the asar s capacity to capture the synoptic circulation discrepancies between observed and predicted asar velocities result predominantly from inadequate wind corrections combined with radar incidence angles below 30 occasionally observed wind induced outliers cause a bias in the estimated asar velocities but do not affect the ability of the asar to systematically image regions of strong surface current flow and shear time averaged maps of asar derived surface current velocity seem able to accurately capture the position as well as the intensity of the agulhas current the ability of the asar to pick up the smaller features of the circulation along the shelf break also shows that variability along the agulhas bank is of the same order of magnitude as that observed in the agulhas retroflection asar surface current velocities offer a very good complement to altimetry in regions where the mean dynamic topography is poorly resolved the quasi synoptic nature of asar acquisitions combined with the relatively high resolution of asar surface current velocities also make it attractive for studies of submesoscale processes and western boundary current dynamics

calcitic dung spherulites and the potential for rapid identification of degraded animal dung at archaeological sites using ftir spectroscopy abstract animal dung is increasingly a valuable resource for reconstructing ancient activity in archaeology one of the most common archaeological indicators of dung in caves and arid environments are calcitic dung spherulites that form in the digestive system of a variety of animals although many aspects of their formation and taphonomy are understood details of their mineralogy remain poorly defined using the fourier transform infrared ftir grinding curve method we report here that archaeological sediments containing large amounts of dung spherulites can be differentiated from sediments composed of other forms of geogenic and pyrogenic calcites we propose that this attribute can be used to rapidly identify well preserved degraded dung deposits at archaeological sites with routine laboratory or on site field ftir analysis this observation at a 5000 year old open air site suggests that the grinding curve method also has potential to be used for assessing preservation of dung spherulites for future radiocarbon or stable isotope investigations

taphonomy of phytoliths and macroplants in different soils from olduvai gorge tanzania and the application to plio pleistocene palaeoanthropological samples the abundance and types of phytoliths in the fossil record are taphonomically biased and do not correspond with the macroplant record to better understand the bias and improve the interpretation of samples from olduvai gorge tanzania we analysed the phytoliths from three sample sets modern grasses sedges palm and dicots in the area modern soils in the area and the fossil soils from the eastern palaeolake margin in lowermost bed ii fourier transform infrared spectrometry analyses were performed in parallel to compare the mineral composition of both modern soils and fossil soils we found that the abundance of phytoliths is greatly reduced in soil samples compared with modern plant material but the morphotypes can be reliably interpreted dicotyledonous wood bark phytoliths appear to be over represented in the soil types grass phytoliths and sedges to a lesser degree are preserved in the soils but in lower abundances resulting in these groups being under represented the macroplant fossils are fragments of grass and sedge aerial culms and dicotyledonous stems that are preserved in fluvial and lacustrine deposits it is suggested that phytoliths represent the continuous flora whereas macroplant fossils represent the more robust tissues of selected plants preserved under more catastrophic conditions a post depositional model is proposed and the palaeovegetation is reinterpreted as being richer and more complex than indicated by other fossil data

geoarchaeology in an urban context the uses of space in a phoenician monumental building at tel dor israel abstract interpretation of past urban societies in the near east whose settlements are known mostly as tell sites is largely based on macro stratigraphy and on the association of architecture with macroscopic artifacts analyses of sediments common in prehistoric sites are rare in tell sites here we show the results of a detailed geoarchaeological study of the micro stratigraphy of a sedimentary sequence associated with early iron age phoenician monumental architecture the study involves mineralogical micromorphological and phytolith analyses and provides new insights into the stratigraphic sequence and the use of architectural spaces the sedimentary sequence examined comprises alternating layers of gray fill deposits and white floors we show that floors made from local calcareous sandstone in the lower part of the sedimentary sequence were heated and are thus in effect plaster floors a concentration of micro laminated trampled fish remains above the most elaborate of these plaster floors indicates activities related to fish processing fine white layers in the upper part of the sedimentary sequence that were considered as plaster based on macroscopic examination are in fact composed almost entirely of opaline grass phytoliths the phytoliths appear in an undulating micro laminated structure and are associated with dung spherulites and phosphate nodules thus probably reflecting livestock penning the formation of phytolith floors involves extensive volume reduction due to the degradation of the organic material and this may result in floor subsidence a phenomenon that is often observed in archaeological sites most fill deposits include macroscopic and microscopic remains of wood ash bones phytoliths charcoal ceramics plaster and mollusk shells reflecting the debris produced from household activities this study shows how a combination of macro stratigraphy with microscopic and mineralogical analyses of the sediments within architectural spaces can provide information on the varying ways in which the space was used through time and also contributes to solving macro stratigraphic problems

ocean surface currents from avhrr imagery comparison with land based hf radar measurements we focus on inverting the surface temperature or heat equation to obtain the surface velocity field in the coastal ocean and compare the results with those from the maximum cross correlation mcc technique and with the in situ velocity fields measured by the rutgers university coastal ocean dynamics radar codar when compared with codar fields velocities from the heat equation and mcc have comparable accuracies but the heat equation technique better resolves the finer scale flow features we use the results to directly calculate the surface divergence and vorticity this is possible because we convert the traditionally underdetermined heat inversion problem to an overdetermined one without constraining the velocity field with divergence vorticity or energy statements because no a priori assumptions are made about the vorticity it can be calculated directly from the velocity results the derived vorticity field has typical open ocean magnitudes 5 times 10 5 s and exhibits several structures a warm core ring gulf stream filament and a diverging flow consistent with the types of flows required to kinematically deform the sea surface temperature patterns into the observed configurations

settlement and environmental history of a multilayered settlement mound in niederroblingen central germany a multi proxy approach a multi disciplinary palaeoecological approach on a sequence of dated archaeosediments was accomplished the sediments derive from a multilayered prehistoric settlement mound in central germany representing the remnants of a prehistoric village based on the analysis of biological remains and geochemical physical analysis of the settlement layers its environment was reconstructed there is a trend to increasing anthropogenic activities and impact on the environment represented through a rise of indicators for productive surplus from the early neolithic 5300 4900 bc until the roman times 400 ad during the early neolithic shifting flat settlements were situated in a locally opened landscape the immediate surrounding of the floodplain was used by the settlers for their economic requirements e g wood from the riparian forest after a hiatus of ca 1900 years a multilayered settlement mount rose from late neolithic times 3000 bc to roman times since the middle bronze age approximately 1500 bc the riparian forest was obviously replaced by agricultural fields and meadows and henceforward the hinterland used by the settlers probably grew in size the continuing demand of wood was maintained by the acquisition of more distant sources the onset of house constructions substituting wood by loam wattle and daub might be a possible societal response to this shortfall this is reflected in the growing thickness and composition of the settlement layers as well as in the archaeological record e g tumbled wattle and daub house walls the rising of the groundwater table and the start of severe floods of the adjacent river helme during pre roman iron age approx 800 100 bc might reflect a geomorphological response to the increased land use intensity at a regional scale

domestic activities and spatial distribution in ain abū nukhayla wadi rum southern jordan the use of phytoliths and spherulites studies abstract the pre pottery neolithic b site of ayn ab nukhayla wadi rum jordan contains structural installations loci composed of inter connected oval rock walled pithouses questions that arose from their study centered on how to identify possible herding and agricultural activities and to assess any differences in how the loci were used the combined study of phytoliths and spherulites identified from different loci are presented here the results of quantitative morphologic and morphometric analyses of phytoliths and spherulites identified in the different loci are discussed cereal processing is evident in some loci by the concentration of the inflorescent parts of festucoid grass phytoliths associated with the presence of handstones and querns these loci appear to have encompassed specific areas in which domestic activities including the grinding of cereals and the preparation of other plant resources were undertaken in contrast other loci such as locus 20 seem to have been used as pens for herd animals sheep goats as indicated by very high densities of spherulites the results of this study provide new insights on plant uses herding practices and the economic diversity of early neolithic communities in the levant

computing advective velocities from satellite images of sea surface temperature a method of employing sequential satellite images of sea surface temperature sst patterns to estimate surface advective current velocities is described sst images are obtained by processing data received twice daily from the advanced very high resolution radiometer the current velocities are estimated by applying a maximum cross correlation mcc technique on two time lapsed images the mcc technique involves computing matrices of cross correlation coefficients and identifying correlation peaks a two stage multilevel statistical test over two dimensional correlations is developed for determining the relative significance levels of velocity estimates the test also identifies areas where the mcc technique cannot be effective aspects of implementation and limitations of the mcc technique for computing current velocity are also discussed advective velocity fields computed through mcc for the chatham rise area in new zealand extending from 40 5 degrees s 173 5 degrees e to 49 degrees s 178 degrees w show good agreement with the known geostrophic flow patterns in this area

remote sensing of ocean currents a method of remotely measuring near surface ocean currents with a synthetic aperture radar sar is described the apparatus consists of a single sar transmitter and two receiving antennas the phase difference between sar image scenes obtained from the antennas forms an interferogram that is directly proportional to the surface current the first field test of this technique against conventional measurements gives estimates of mean currents accurate to order 20 percent that is root mean square errors of 5 to 10 centimeters per second in mean flows of 27 to 56 centimeters per second if the full potential of the method could be realized with spacecraft then it might be possible to routinely monitor the surface currents of the world s oceans

direct ocean surface velocity measurements from space improved quantitative interpretation of envisat asar observations previous analysis of advanced synthetic aperture radar asar signals collected by esa s envisat has demonstrated a very valuable source of high resolution information namely the line of sight velocity of the moving ocean surface this velocity is estimated from a doppler frequency shift consistently extracted within the asar scenes the doppler shift results from the combined action of near surface wind on shorter waves longer wave motion wave breaking and surface current both kinematic and dynamic properties of the moving ocean surface roughness can therefore be derived from the asar observations the observations are compared to simulations using a radar imaging model extended to include a doppler shift module the results are promising comparisons to coincident altimetry data suggest that regular account of this combined information would advance the use of sar in quantitative studies of ocean currents

comparison of velocity estimates from advanced very high resolution radiometer in the coastal transition zone two methods of estimating surface velocity vectors from advanced very high resolution radiometer avhrr data were applied to the same set of images and the results were compared with in situ and altimeter measurements the first method used an automated feature tracking algorithm and the second method used an inversion of the heat equation the 11 images were from 3 days in july 1988 during the coastal transition zone field program and the in situ data included acoustic doppler current profiler adcp vectors and velocities from near surface drifters the two methods were comparable in their degree of agreement with the in situ data yielding velocity magnitudes that were 30 50 less than drifter and adcp velocities measured at 15 20 m depth with rms directional differences of about 60 these differences compared favorably with a baseline difference estimate between adcp vectors interpolated to drifter locations within a well sampled region high correlations between the avhrr estimates and the coincident geosat geostrophic velocity profiles suggested that the avhrr methods adequately resolved the important flow features the flow field was determined to consist primarily of a meandering southward flowing current interacting with several eddies including a strong anticyclonic eddy to the north of the jet incorporation of sparse altimeter data into the avhrr estimates gave a modest improvement in comparisons with in situ data

three recent larger earthquakes offshore norway three earthquakes of magnitude around 5 occurred offshore western norway on 5th february 1986 on 8th august 1988 and on 23rd january 1989 these earthquakes representing the highest seismic activity level in this area for at least 30 years were all felt by people over most of southern and central norway focal mechanism solutions for these earthquakes indicate thrust faulting along n s to nne ssw striking fault planes in response to nw se compressional stress most probably of plate tectonic origin a number of high quality digital recordings of the ground motions at various distances from these and other recent earthquakes in norway have shown that source spectral as well as wave attenuation characteristics in this area are reasonably consistent with what has been derived from other intraplate areas

airborne synthetic aperture radar observations of spiral eddy slick patterns in the southern california bight 1 repeat sampling on hourly time scales using an airborne synthetic aperture radar sar is used to investigate the occurrence and evolving characteristics of spiral shaped slick patterns commonly presumed to be indicators of submesoscale ocean eddies in the area around santa catalina island california 33 4 n 118 4 w simultaneous sar imagery and boat survey data are examined over two 5 h long periods spaced 3 days apart in april 2003 the sar imagery reveals several spiral like patterns roughly 5 km in diameter occurring downstream of the western end of catalina we believe that the most likely formation mechanism for these patterns is current wake instability related to the flow of the southern california countercurrent along the north shore of catalina in one case there is an observed cold core eddy and vortex sheet attached to the tip of the island similar to island wake simulations done by dong and mcwilliams 2007 in another case the sar imagery shows a series of slick patterns that at least initially resemble spiral eddies but the data show no clear evidence of actual ocean eddies being present either at depth or through a rotating surface expression a speculation is that such features signify island wake eddies that are relatively weak and dissipate quickly an unexpected finding was how quickly a spiral slick pattern could deteriorate suggesting a time scale for the surface feature of the order of only several hours an implication of this result is that care is needed when interpreting a single satellite sar imagery for evidence of active submesoscale eddies recommendations are made for future field studies

retrieval of sea surface range velocities from envisat asar doppler centroid measurements the processing steps and error corrections needed to retrieve estimates of sea surface range doppler velocities from envisat advanced synthetic aperture radar wide swath medium resolution image products are presented retrieval accuracies based on examination of the corrected doppler shift measurements are assessed the root mean square errors of the doppler shift after bias corrections are found to be 4 7 and 3 9 hz in vv and hh polarizations respectively at 35 incidence angle this corresponds to horizontal doppler velocities of 23 and 19 cm s

settling in sahul investigating environmental and human history interactions through micromorphological analyses in tropical semi arid north west australia the pleistocene continent of sahul was first settled by people who arrived by watercraft from island south east asia about 50 000 years ago some of the oldest archaeological sites in sahul are located in the southern kimberley in northwest australia this area lies within the southern zone of influence of the tropical monsoon and thus has always been highly sensitive to changes in monsoon dynamics over time how these climatic changes have affected the colonisation and occupation of australia is an important research theme in australian archaeology this paper illustrates the contribution and challenges of micromorphology in deciphering palaeoenvironmental and anthropogenic markers in a still largely unexplored australian context micromorphological analysis of two archaeological sequences in the napier range carpenters gap 1 and 3 provides a complementary and comprehensive reconstruction of the human climate history in this area spanning nearly 50 000 years of australian human presence the results demonstrate an opportunistic use of sites by people through time surprisingly independent of local climatic variation suggesting highly flexible subsistence strategies

derivation of sea surface tidal current from spaceborne sar constellation data in this paper we demonstrate an application of spaceborne synthetic aperture radar sar constellation data to derive sea surface tidal current at high spatial resolution the maximum cross correlation mcc method which has been widely applied to optical remote sensing data to derive sea surface velocities is applied to x band sar data from terrasar x tsx and tandem x tdx which were operating in pursuit monostatic mode because of the short temporal interval of tsx and tdx s pursuit acquisitions temporal de correlation is minimized to derive tidal current fields that exhibit significant temporal and spatial variations in addition we combined data from tdx and another x band sar cosmo skymed to obtain a virtual sar constellation data pair which was also analyzed using the mcc method to derive the tidal current field case studies of hangzhou bay in the east china sea and amrum island in the north sea are presented the sar derived tidal current fields were compared to the results of numerical model simulations high frequency hf radar measurements and in situ measurements mcc coefficients that are greater than 0 8 are an appropriate threshold for the further derivation of tidal currents comparisons to finite volume community ocean model hf radar and general estuarine transport model results yield root mean square errors of 0 13 0 06 and 0 05 m s respectively measurements from three field stations were also compared to the mcc sar retrievals yielding differences of 0 3 0 07 and 0 09 m s

an improved composite surface model for the radar backscattering cross section of the ocean surface 2 model response to surface roughness variations and the radar imaging of underwater bottom topography in the companion paper we have presented an improved composite surface model for the calculation of normalized radar backscattering cross sections nrcs of the ocean surface the proposed model accounts for the impact of the full two dimensional ocean wave spectrum on the radar backscatter and was shown to reproduce measured absolute nrcs values for a variety of radar configurations and wind speeds satisfactorily after some reasonable tuning of the input ocean wave spectrum this paper focuses on the modulation of the nrcs in the presence of spatially varying surface currents first the sensitivity of the nrcs to intensity variations of different ocean wave spectral components is investigated then the hydrodynamic modulation of the wave spectrum over underwater bottom topography in tidal waters is computed in different ways and the resulting radar signatures are discussed the composite surface model yields comparable radar signatures at high 10 ghz x band and low 1 ghz l band radar frequencies which is in much better agreement with experimental results than the predictions of a first order bragg scattering model on the other hand measured variations of the nrcs at high radar frequencies appear to be still underestimated in some cases which may be due to shortcomings of our description of the wave current interaction by conventional weak hydrodynamic interaction theory possible improvements of the theory are discussed and requirements for future experiments are formulated

calcium iron phosphate features in archaeological sediments characterization through microfocus synchrotron x ray scattering analyses the occurrence of amorphous calcium ca iron fe phosphate infilling features in thin section samples from archaeological stratigraphies is increasingly being reported and used in the cultural interpretations of sites in some contexts these materials are the product of dissolution and recrystallization of bone material within pores of the soil or sediment matrix this study uses transmitted microfocus x ray scattering to characterize and measure features of known cod fish bone gadus morhua materials and compare them to archaeological samples of amorphous ca fe phosphate infilling material found in thin section from early fishing community sites the analyses characterize the structure of these features for the first time and allow discussion of the diagenetic processes that lead to their formation

velocity observations of the california current derived from satellite imagery 1 this research examines the potential of ocean velocity observations generated from the maximum cross correlation technique mcc applied to thermal infrared imagery to capture the total current at a high sampling rate especially in the nearshore region allowing for a novel view of the california current comparison of 12 years of weekly ocean velocity fields derived from the mcc method with velocity observations from drifting buoys reveals strong correspondence between the data sets the mcc method however is able to produce over 10 times the number of observations comparison of mcc velocities with geostrophic velocities from altimetry demonstrates differences that suggest ageostrophic currents in the mcc observations that are likely wind driven the time averaged mean velocity field from mcc observations reveals strong offshore jet like features that extend off of coastline promontories eddy statistics from the mcc velocity observations indicate dramatically different dynamics in the nearshore and offshore regions differences in spatial statistics derived from the mcc observations compared to previous studies of the region are attributed to wind driven currents in the observations that can dominate the variability of the current in the nearshore region