vegetation and environmental changes in northern anatolia between 134 and 119 ka recorded in black sea sediments this multiproxy study on se black sea sediments provides the first detailed reconstruction of vegetation and environmental history of northern anatolia between 134 and 119 ka here the glacial interglacial transition is characterized by several short lived alternating cold and warm events preceding a meltwater pulse 130 4 131 7 ka the latter is reconstructed as a cold arid period correlated to heinrich event 11 the initial warming is evidenced at 130 4 ka by increased primary productivity in the black sea disappearance of ice rafted detritus and spreading of oaks in anatolia a younger dryas type event is not identifiable the eemian vegetation succession corresponds to the main climatic phases in europe i the quercus juniperus phase 128 7 126 4 ka indicates a dry continental climate ii the ostrya corylus quercus carpinus phase 126 4 122 9 ka suggests warm summers mild winters and high year round precipitation iii the fagus carpinus phase 122 9 119 5 ka indicates cooling and high precipitation and iv increasing pinus at 121 ka marks the onset of cooler drier conditions generally pollen reconstructions suggest altitudinal latitudinal migrations of vegetation belts in northern anatolia during the eemian caused by increased transport of moisture the evidence for the wide distribution of fagus around the black sea contrasts with the european records and is likely related to climatic and genetic factors

holocene climate variability in the levant from the dead sea pollen record abstract the dead sea located at the deepest place on continent and between the subtropical mediterranean zone and the desert reflects in its water composition and levels and sedimentary records the hydrological conditions in the southern levant region temporal variations in rainfall and temperatures of the holocene levant are reconstructed here from pollen data recovered from a sediment core drilled at the ein gedi shore applying a novel biome model based on bayesian statistics our results suggest that the region was arid and warm in the early holocene period 10 6 5 ka cal bp wetter and colder in the mid holocene 6 3 3 3 ka cal bp and drier and warmer in the late holocene 3 2 ka cal bp to present these periods comprise multi centennial climate cycles that are characterized by rapid changes in temperature and precipitation reflecting sea surface temperature sst and atmospheric conditions over the atlantic ocean the pollen record responds within a short time interval to the climate conditions and marks rapid shifts from mediterranean to desert environmental conditions and back in the southern levant region we also evaluate our results in the light of possible disturbances of the natural vegetation e g the possibility of forest decrease since the neolithic

reconstructing biomes from palaeoecological data a general method and its application to european pollen data at 0 and 6 ka biome models allow the results of experiments with atmospheric general circulation models to be translated into global maps of potential natural vegetation the use of biome models as a diagnostic tool for palaeoclimate simulations can yield maps that are directly comparable with palaeoecological pollen and plant macrofossil records provided these records are biomized i e assigned to biomes in a consistent way this article describes a method for the objective biomization of pollen samples based on fuzzy logic pollen types taxa are assigned to one or more plant functional types pfts then affinity scores are calculated for each biome in turn based on its list of characteristic pfts the pollen sample is assigned to the biome to which it has the highest affinity subject to a tie breaking rule modern pollen data from surface samples reflecting present vegetation across europe are used to validate the method pollen data from dated sediment cores are then used to reconstruct european vegetation patterns for 6 ka the reconstruction shows systematic differences from present that are consistent with previous interpretations the method has proved robust with respect to human impacts on vegetation and provides a rational way to interpret combinations of pollen types that do not have present day analogs the method demands minimal prior information and is therefore equally suitable for use in other regions with richer floras and or lower densities of available modern and fossil pollen samples than europe

insolation values for the climate of the last 10 million years new values for the astronomical parameters of the earth s orbit and rotation eccentricity obliquity and precession are proposed for paleoclimatic research related to the late miocene the pliocene and the quaternary they have been obtained from a numerical solution of the lagrangian system of the planetary point masses and from an analytical solution of the poisson equations of the earth moon system the analytical expansion allows the direct determination of the main frequencies with their phase and amplitude numerical and analytical comparisons with the former astronomical solution ber78 are performed so that the accuracy and the interval of time over which the new solution is valid can be estimated the corresponding insolation values have also been computed this analysis leads to the conclusion that the new values are expected to be reliable over the last 5 ma in the time domain and at least over the last 10 ma in the frequency domain

calcareous nannofossil response to late cretaceous climate change in the eastern tethys zagros basin iran abstract coniacian to maastrichtian changes in calcareous nannofossil assemblages have been investigated in the eastern tethyan shahneshin section central zagros basin iran the nannofossil assemblages are mainly composed of watznaueria spp avg 54 retecapsa spp avg 7 9 cribrosphaerella ehrenbergii avg 7 7 and micula spp avg 5 7 throughout the late campanian there is a trend to lower abundances in watznaueria spp together with increasing abundances of c ehrenbergii and arkhangelskiella cymbiformis which are considered in this basin as the main cool water taxa our results reveal that despite a diagenetic impact on calcareous nannoflora a number of primary paleoecological trends are preserved which depict well features of the progressive late cretaceous cooling the first pronounced cooling episode occurs across the late campanian to early maastrichtian the onset of pronounced cooling in the eastern tethys appears to occur prior to the campanian maastrichtian boundary event cmbe 13c negative excursion in contrast with the boreal realm where pronounced cooling only occurs in the early maastrichtian postdating the onset of the cmbe the coincidence of this earlier cooling in the zagros basin with an interval characterized by a significant increase in benthic foraminifera suggests an amplified response of the assemblage due to a change to shallower environments hence the late campanian calcareous nannofossil assemblage turnover in central zagros is either a response to an early cooling trend in the eastern tethys or to sea level fall or both the mid maastrichtian warming and late maastrichtian cooling episodes are also delineated in the nannofossil assemblage of shahneshin and likely correlate with similar episodes in the boreal realm

holocene palaeoecology of the golan heights near east investigation of lacustrine sediments from birkat ram crater lake abstract lacustrine deposits of the crater lake birkat ram located in the northern golan heights have been used as a paleoecological archive preliminary sedimentological and palynological investigations based on a composite profile allow the reconstruction of the environmental history of the last 6500 years fluctuations of the pollen composition trees and shrubs versus herbs values of oak and olive tree correspond to changes in different sediment parameters total organic carbon magnetic susceptibility which can be interpreted as the effects of human impact on the geo biosphere four phases with strong settlement activities can be identified for the northern golan heights 1 during the chalcolithic period early bronze age 2 during the hellenistic roman byzantine periods 3 during the crusader period and finally during modern time these periods were interrupted by wooded regeneration phases with low anthropogenic activities

abrupt changes of temperature and water chemistry in the late pleistocene and early holocene black sea new mg ca sr ca and published stable oxygen isotope and 87sr 86sr data obtained on ostracods from gravity cores located on the northwestern black sea slope were used to infer changes in the black sea hydrology and water chemistry for the period between 30 to 8 ka b p calibrated radiocarbon years the period prior to 16 5 ka b p was characterized by stable conditions in all records until a distinct drop in 18o values combined with a sharp increase in 87sr 86sr occurred between 16 5 and 14 8 ka b p this event is attributed to an increased runoff from the northern drainage area of the black sea between heinrich event 1 and the onset of the bolling warm period while the mg ca and sr ca records remained rather unaffected by this inflow they show an abrupt rise with the onset of the bolling allerod warm period this rise was caused by calcite precipitation in the surface water which led to a sudden increase of the sr ca and mg ca ratios of the black sea water the stable oxygen isotopes also start to increase around 15 ka b p although in a more gradual manner due to isotopically enriched meteoric precipitation while sr ca remains constant during the following interval of the younger dryas cold period a decrease in the mg ca ratio implies that the intermediate water masses of the black sea temporarily cooled by 1 2 c during the younger dryas the 87sr 86sr values drop after the cessation of the water inflow at 15 ka b p to a lower level until the younger dryas where they reach values similar to those observed during the last glacial maximum this might point to a potential outflow to the mediterranean sea via the sea of marmara during this period the inflow of mediterranean water started around 9 3 ka b p which is clearly detectable in the abruptly increasing mg ca sr ca and 87sr 86sr values the accompanying increase in the 18o record is less pronounced and would fit to an inflow lasting 100 a

evidence of lateglacial and holocene climatic change and human impact in eastern anatolia high resolution pollen charcoal isotopic and geochemical records from the laminated sediments of lake van turkey annually laminated sediments from lake van spanning about 13000 varve years were sampled for stable isotopic geochemical pollen and charcoal analyses in order to find evidence of past regional climatic changes and human impact in the semi arid region of eastern anatolia turkey the lateglacial period was cold and dry with steppe vegetation and saline lake water during the younger dryas the lake level dropped dramatically and the vegetation turned to a semi desert geochemical and isotopic records indicate a strong increase in moisture at the onset of the holocene and artemisia chenopod steppes were partly replaced by grass steppe and pistachio scrub a delay of about 3000 years in the expansion of deciduous oak woodlands and high steppe fire frequencies suggest dry spring and summer weather during the early holocene at 8200 yr bp a shift in the regional climate regime facilitated the transport of more moisture into the interior areas of the taurus mountains and caused a change in the seasonal distribution of precipitation the steppe forests dominated by quercus advanced and reached their maximum extention at about 6200 yr bp all the proxy data indicate optimum climatic conditions low water salinity and high lake level between 6200 and 4000 yr bp after 4000 yr bp aridity increased again and the modern climatic situation was established human impact in the catchment of lake van started at 3800 yr bp and was intensified during the last 600 years

vegetation and environmental dynamics in the southern black sea region since 18 kyr bp derived from the marine core 22 gc3 abstract sediments from the black sea a region historically dominated by forests and steppe landscapes are a valuable source of detailed information on the changes in regional terrestrial and aquatic environments at decadal to millennial scales here we present multi proxy environmental records pollen dinoflagellate cysts ca ti and oxygen isotope data from the uppermost 305 cm of the core 22 gc3 42 13 53 n 36 29 55 e collected from a water depth of 838 m in the southern part of the black sea in 2007 the records span the last 18 kyr all ages are given in cal kyr bp the pollen data reveal the dominance of the artemisia steppe in the region suggesting rather dry cold environments 18 14 5 kyr bp warming humidity increase during melt water pulses 16 1 14 5 kyr bp indicated by 18o records from the 22 gc3 core sediment and from the sofular cave stalagmite is expressed in more negative 13c values from the sofular cave usually interpreted as the spreading of c3 plants the records representing the interstadial complex 14 5 12 9 kyr bp show an increase in temperature and moisture indicated by forest development increased primary productivity and reduced surface run off whereas the switch from primary terrigenous to primary authigenic ca origin occurs 500 yr later the younger dryas cooling is clearly demonstrated by more negative 13c values from the sofular cave and a reduction of pines the early holocene 11 7 8 5 kyr bp interval reveals relatively dry conditions compared to the mostly moist and warm middle holocene 8 5 5 kyr bp which is characterized by the establishment of the species rich warm mixed and temperate deciduous forests in the low elevation belt temperate deciduous beech hornbeam forests in the middle and cool conifer forest in upper mountain belt the border between the early and middle holocene in the vegetation records coincides with the opening of the mediterranean corridor at 8 3 kyr bp as indicated by a marked change in the dinocyst assemblages and in the sediment lithology changes in the pollen assemblages indicate a reduction in forest cover after 5 kyr bp which was likely caused by increased anthropogenic pressure on the regional vegetation

origin and consequences of cyclic ice rafting in the northeast atlantic ocean during the past 130 000 years deep sea sediment cores recovered from the northeast atlantic ocean were examined in order to elucidate the influence of the earth s orbital parameters on major ice rafting analyses of coarse grained ice rafted debris and planktonic foraminifers revealed a strong reaction to the precession signal since 130 000 yr b p dropstone layers have been deposited each half period of a precessional cycle 11 000 1000 yr ice rafting occurs during times of winter minimum summer maximum insolation and summer minimum winter maximum insolation in the first case high summer insolation forces meltwater discharge from the ice sheets into the polar seas which subsequently enhances formation of sea ice during the winter in the second case growth of continental ice enhances iceberg production which also leads to a salinity reduction of surface seawater both situations result in a southward penetration of polar water thus the marine record of dropstones documents ice rafting not only during weichselian stades but also during cold events within interstades the regularity of ice rafting yields a useful framework to calibrate and elucidate climatic changes not only in the region of the north atlantic ocean but also in remote areas such as the pacific ocean and the antarctic

two step deglaciation at the oxygen isotope stage 6 5e transition the zeifen kattegat climate oscillation comparison of marine lacustrine and terrestrial records from twenty four sites suggests the existence of a younger dryas type climate oscillation just prior to the oxygen isotope stage 6 5e boundary these records include results from biostratigraphic pedostratigraphic and speleothem studies as well as analyses of stable isotope compositions of marine records and ice cores the climate oscillation is named after the warm zeifen interstadial and the cold kattegat stadial the zeifen interstadial may be related to a major meltwater pulse in the baffin bay labrador sea norwegian sea region the climate oscillation is presumably in part a result of a variation in ocean circulation especially in the strength of the north atlantic drift but changes in the atmospheric circulation also played an important role the geographically widespread distribution of the oscillation suggests that the two step deglaciation influenced both the northern and southern hemispheres c 1996 elsevier science ltd

late quaternary paleoclimate in the eastern mediterranean region from stable isotope analysis of speleothems at soreq cave israel abstract the eastern mediterranean continental paleoclimate during the past 25 000 years was determined by a high resolution petrographic stable isotopic and age study of speleothems from soreq cave israel 18o 13c trends indicate that all speleothems older than 7000 yr formed under conditions that differ from those of today the period from 25 000 to 17 000 yr b p was characterized by the highest 18o and 13c values which indicate deposition at temperatures of 12 16 c annual rainfall of 300 450 mm and vegetation typical of a mixed c3 c4type from 17 000 to 10 000 yr b p deglaciation in northern europe 18o values dropped progressively correlative with warming 2 3 c and a gradual increase in precipitation a simultaneous decrease in 13c gives a range expected for c3 type vegetation this period also shows significant 18o and 13c spikes which are correlatable with global events e g heinrich events and the younger dryas stade the speleothems that grew between 10 000 and 7000 yr b p have a unique petrography showing irregular thin laminae of various colors and much detritus they have the lowest 18o corresponding to 1000 mm rain coupled with the highest 13c caused by flooding events which stripped the soil cover from 7000 to 1000 yr b p conditions became closer to those of today this study demonstrates that global events which were recognized in northern europe and north africa are also evident in the eastern mediterranean and are reflected principally by large changes in the rainfall rate

the sea of marmara during marine isotope stages 5 and 6 abstract multi proxy analyses and lithology of two cores mrs cs18 and mrs cs27 from the imrali basin of the sea of marmara som provide novel information on environmental conditions relative sea level and sill depths of the straits of bosporus and dardanelles during the marine isotope stages mis 5 and 6 the fossil and multi proxy geochemical records show that lacustrine conditions prevailed in the som during most of mis 6 from 171 to 134 ka bp and that the transition to marine conditions during termination ii took place at 134 06 1 10 ka bp mis 5 interstadials a c and e witnessed the formation of three sapropels msap 2 msap 3 and msap 4 under suboxic to anoxic marine conditions whereas during stadials mis 5b 94 86 and mis 5d 112 105 ka bp lacustrine and marine conditions with deposition of sediments having relatively low toc contents the som geochemical proxy records correlate well with the regional terrestrial and marine records and the ngrip oxygen isotope record with its stadial and interstadial phases showing the common effect of the north atlantic climatic events triggered by the perturbations in the atlantic meridional overturning circulation however the amplitude of the oscillations recorded in the som during mis 6 penultimate glacial period is relatively small compared to the mis 4 to mis 2 last glacial period

heinrich events massive late pleistocene detritus layers of the north atlantic and their global climate imprint 1 millennial climate oscillations of the glacial interval are interrupted by extreme events the so called heinrich events of the north atlantic their near global footprint is a testament to coherent interactions among earth s atmosphere oceans and cryosphere on millennial timescales heinrich detritus appears to have been derived from the region around hudson strait it was deposited over approximately 500 250 years several mechanisms have been proposed for the origin of the layers binge purge cycle of the laurentide ice sheet jokulhlaup activity from a hudson bay lake and an ice shelf buildup collapse fed by hudson strait to determine the origin of the heinrich events i recommend 1 further studies of the timing and duration of the events 2 further sedimentology study near the hudson strait and 3 greater spatial and temporal resolution studies of the layers as well as their precursory intervals studies of previous glacial intervals may also provide important constraints

multicentennial scale hydrological changes in the black sea and northern red sea during the holocene and the arctic north atlantic oscillation 1 paleoenvironmental proxy data for ocean properties eolian sediment input and continental rainfall based on high resolution analyses of sediment cores from the southwestern black sea and the northernmost gulf of aqaba were used to infer hydroclimatic changes in northern anatolia and the northern red sea region during the last 7500 years pronounced and coherent multicentennial variations in these records reveal patterns that strongly resemble modern temperature and rainfall anomalies related to the arctic oscillation north atlantic oscillation ao nao these patterns suggest a prominent role of ao nao like atmospheric variability during the holocene beyond interannual to interdecadal timescales most likely originating from solar output changes

first high resolution marinopalynological stratigraphy of late quaternary sediments from the central part of the bulgarian black sea area abstract spores pollen and dinoflagellate cysts of late pleistocene and holocene sediments were analyzed from giant gravity core 18 from the black sea continental slope recovered from a water depth of 971 m the investigated length of the core is 203 5 cm it includes 3 lithological units light grey clay sapropels and coccolith bearing ooze the core was sampled at 5 10 cm intervals sampling of the interval 141 5 126 cm was carried out at every cm ams radiocarbon dating of bulk organic carbon was performed on 18 selected sediment layers this chronological data allowed the first high resolution pollen stratigraphy of late quaternary sediments from the western black sea area to be presented the percentage spore pollen diagram is divided into 6 local pollen assemblage zones the trends in the vegetation dynamics and climate changes and the early history of migration of the majority of the arboreal taxa that nowadays occur in the eastern balkan range were traced out the palynological record suggests that open oak forests were spread in the eastern balkan range at the beginning of the holocene and shows early migration of the major temperate arboreal species such as quercus ulmus tilia and carpinus betulus this vegetation palaeosuccession continues with the spreading of mixed oak forests from 8950 until 2620 cal bp 8650 40 until 3120 35 14c bp followed by destructive changes due to human impact and climate deterioration a cooling of holocene climate that is well known in the north atlantic region as the 8200 yrs cold event is identified for the first time in marine records from the bulgarian black sea area the assemblages of dinoflagellate cysts and acritarchs were investigated to provide a reconstruction of surface seawater salinity and surface seawater temperature changes two main dinoflagellate cyst assemblages one dominated by fresh to brackish water species such as spiniferites cruciformis and pyxidinopsis psilata and a subsequent one that is characterized by euryhaline marine mediterranean species such as lingulodinium machaerophorum spiniferites belerius spiniferites bentorii operculodinium centrocarpum and acritarchs cymatiosphaera globulosa testified a change in sss from low salinity

comparison of quantification methods to measure fire derived black elemental carbon in soils and sediments using reference materials from soil water sediment and the atmosphere black carbon bc the product of incomplete combustion of fossil fuels and biomass called elemental carbon ec in atmospheric sciences was quantified in 12 different materials by 17 laboratories from different disciplines using seven different methods the materials were divided into three classes 1 potentially interfering materials 2 laboratory produced bc rich materials and 3 bc containing environmental matrices from soil water sediment and atmosphere this is the first comprehensive intercomparison of this type multimethod multilab and multisample focusing mainly on methods used for soil and sediment bc studies results for the potentially interfering materials which by definition contained no fire derived organic carbon highlighted situations where individual methods may overestimate bc concentrations results for the bc rich materials one soot and two chars showed that some of the methods identified most of the carbon in all three materials as bc whereas other methods identified only soot carbon as bc the different methods also gave widely different bc contents for the environmental matrices however these variations could be understood in the light of the findings for the other two groups of materials i e that some methods incorrectly identify non bc carbon as bc and that the detection efficiency of each technique varies across the bc continuum we found that atmospheric bc quantification methods are not ideal for soil and sediment studies as in their methodology these incorporate the definition of bc as light absorbing material irrespective of its origin leading to biases when applied to terrestrial and sedimentary materials this study shows that any attempt to merge data generated via different methods must consider the different operationally defined analytical windows of the bc continuum detected by each technique as well as the limitations and potential biases of each technique a major goal of this ring trial was to provide a basis on which to choose between the different bc quantification methods in soil and sediment studies in this paper we summarize the advantages and disadvantages of each method in future studies we strongly recommend the evaluation of all methods analyzing for bc in soils and sediments against the set of bc reference materials analyzed here

holocene environmental change and its impact on sediment dynamics in the eastern mediterranean abstract investigators have studied past environmental change in the eastern mediterranean region from a number of perspectives while climate reconstructions and palynological research have focused on forces that drive the geomorphologic system many researchers have attempted to use sediment archive studies to identify periods of change in sediment dynamics due to the large variability in environmental parameters and the variety of landscapes present in the eastern mediterranean region research has focused on sediment archives ranging from small colluvial sites to deltas of large rivers on the mediterranean coast as the cultural record for the region is extremely rich the main goal of palaeo environmental research in the eastern mediterranean has been to identify the relative importance of human impact on the landscape nevertheless sediment archives have significant limitations chronological control for many palaeo environmental records is highly uncertain and rates of landscape change are oftentimes difficult to assess most palaeo environmental research has been conducted on or near archeological sites where direct human impact may obscure the indirect impact on sediment dynamics through land use changes quantification and modeling of sediment dynamics in the eastern mediterranean environment offer one solution when erosion and sediment transport rate analyses are incorporated periods of relatively important change can be identified using multiple approaches the relative importance of the main driving forces climate and land use become distinguishable since field based data from the actual sediment archives remain vital an overview of numerous studies in the eastern mediterranean is provided in order to draw a general picture for different time periods and the relative scale of regional landscape development during the holocene a comparison of sediment dynamics with the record of driving forces indicates that while climate was the main driver of the geomorphic system during the early holocene at some point human impact became widespread and began to dictate sediment dynamics to a large extent from the byzantine period onward soil properties seem to play an increasingly important role as the hillslope soil reservoir in the eastern mediterranean was progressively depleted during the late holocene

simulating arctic climate warmth and icefield retreat in the last interglaciation in the future arctic warming and the melting of polar glaciers will be considerable but the magnitude of both is uncertain we used a global climate model a dynamic ice sheet model and paleoclimatic data to evaluate northern hemisphere high latitude warming and its impact on arctic icefields during the last interglaciation our simulated climate matches paleoclimatic observations of past warming and the combination of physically based climate and ice sheet modeling with ice core constraints indicate that the greenland ice sheet and other circum arctic ice fields likely contributed 2 2 to 3 4 meters of sea level rise during the last interglaciation

timing and hydrological conditions of sapropel events in the eastern mediterranean as evident from speleothems soreq cave israel this paper explores the connection between the timing of sapropel events in the eastern mediterranean sea and the time of low 18o events in speleothems of the soreq cave israel a new well dated 18o and 13c profile of the soreq cave speleothems for the last 140 kyr reveals five prominent low 18o events dated at 124 to 119 kyr with the main peak at 122 kyr event v 108 to 100 kyr with peaks at 107 and 102 kyr event iv 85 to 79 kyr with peak at 80 kyr event iii 55 to 52 kyr with a peak at 54 kyr event ii and 8 5 to 7 kyr with peaks at 8 5 and 7 kyr event i these events are characteristic of period of enhanced rainfall in the eastern mediterranean area particularly so for events v and i where the marked decrease in 18o and the correspondingly marked increase in 13c indicate very wet conditions the chronology of the low 18o events v iv iii and i match the ages estimated for the formation of sapropels s5 s4 s3 and s1 which are also associated with high hydrological activity thus it is suggested that the low 18o events in the soreq cave speleothems constrain the maximum duration of the sapropel formation pollen data from the sapropel layers and the isotopic pattern of the speleothems indicate that sapropels s5 and s1 were deposited during very wet periods when there were major decrease in the sea surface salinity coupled with frost free winters and drought free summers sapropels s4 and s3 were formed during periods of increased precipitation but ones in which the general climate was mediterranean semi arid

dinoflagellate cysts as indicators of climatic and oceanographic changes during the past 40 kyr in the santa barbara basin southern california 1 the dinoflagellate cyst record from ocean drilling program hole 893a santa barbara basin southern california is examined at millennial scale resolution for the past 40 kyr changes in cyst abundance composition of cyst assemblages and their diversity reflect major shifts in climate and ocean circulation in the region over this time interval throughout the sequence dinoflagellate cyst assemblages are dominated by heterotrophic dinoflagellates brigantedinium spp and other upwelling related taxa such as echinidinium and protoperidinium americanum are abundant indicating the continued influence of coastal upwelling on the basin during the late quaternary a significant increase in cyst accumulation rates is seen during the holocene and to a lesser extent during shorter warming events such as bolling allerod and dansgaard oeschger interstadials implying enhanced marine productivity during these periods cyst diversity is high during the holocene an increase in abundance of cysts produced by autotrophic dinoflagellates in the late holocene suggests enhanced input of warm nutrient rich waters in contrast cyst assemblages from the last glacial maximum exhibit a relatively low diversity and an increase in the cysts of heterotrophic dinoflagellates in particular selenopemphix nephroides the presence of this taxon in association with brigantedinium spp implies substantial cooling of surface waters in the santa barbara basin at that time

a late pleistocene long pollen record from lake urmia nw iran abstract a palynological study based on two 100 m long cores from lake urmia in northwestern iran provides a vegetation record spanning 200 ka the longest pollen record for the continental interior of the near east during both penultimate and last glaciations a steppe of artemisia and poaceae dominated the upland vegetation with a high proportion of chenopodiaceae in both upland and lowland saline ecosystems while juniperus and deciduous quercus trees were extremely rare and restricted to some refugia hippophae rhamnoides constituted an important phanerophyte particularly during the late last glacial period a pronounced expansion in ephedra shrub steppe occurred at the end of the penultimate late glacial period but was followed by extreme aridity that favoured an artemisia steppe very high lake levels registered by both pollen and sedimentary markers occurred during the middle of the last glaciation and late part of the penultimate glaciation the late glacial to early holocene transition is represented by a succession of hippophae ephedra betula pistacia and finally juniperus and quercus the last interglacial period eemian slightly warmer and moister than the holocene was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern european pollen sequences

sea land oxygen isotopic relationships from planktonic foraminifera and speleothems in the eastern mediterranean region and their implication for paleorainfall during interglacial intervals the oxygen and carbon stable isotope compositions of cave speleothems provide a powerful method for understanding continental climate change here we examine the question of the regionality of this isotopic record and its linkage with the marine isotopic record in the eastern mediterranean em region the study presents a new accurately dated 250 kyr 18o and 13c record determined from speleothems of the peqiin cave northern israel its comparison with the continuous 185 kyr isotopic record of the soreq cave speleothems from central israel reveals striking similarities thus a strong regional climatic signal brought about by variations in temperature and rainfall amount is reflected in both cave records low 18o minima in the peqiin profile for the last 250 to 185 kyr period interglacial marine isotopic stage 7 match the timing of sapropels 9 to 7 and are indicative of high rainfall in the em region at these times the combined soreq and peqiin 18o record for the last 250 kyr excellently matches the published globigerinoides ruber g ruber marine 18o record for the em sea with the isotopic compositional difference g ruber speleothems remaining relatively constant at 5 6 0 7 thus establishing for the first time a robust exploitable link between the land and the marine isotopic records the correspondence of low 18o speleothem values and high cave water stands with low g ruber 18o values during interglacial sapropel events indicates that these periods were characterized by enhanced rainfall in the em land and sea regions by use of sea surface temperatures derived from alkenone data as a proxy for land temperatures at the soreq cave we calculate the paleorainfall 18o values and its amounts maximum rainfall and lowest temperature conditions occurred at the beginning of the sapropel events and were followed by decrease in rainfall and increase in temperatures leading to arid conditions the record for the last 7000 yr shows a trend toward increasing aridity and agrees well with climatic and archeological data from north africa and the middle east

multiproxy climate reconstructions for the eemian and early weichselian palaeobotanical coleopteran and periglacial data from 106 sites across northwestern europe have been analysed in order to reconstruct palaeoclimatic conditions during the eemian and early weichselian three time slices in the eemian and four in the early weichselian have been considered in the pinus quercetum mixtum corylus phase of the eemian summer temperatures were probably at their highest and the botanic evidence suggests a southeast to northwest gradient for both the warmest and coldest month coleoptera indicate that the summers in southern england were several degrees warmer than those of present day the climate during thecarpinus picea phase was uniform and oceanic without obvious gradients in the final time slice of the eemian the pinus picea abies phase temperatures of the warmest month seem to drop slightly with some indication of a shift towards a more boreal and suboceanic climate the reconstruction of the palaeoclimate in the herning stadial and rederstall stadial is hampered by the limited number of sites but botanical evidence suggests a gradient in temperature of the coldest month from east to west coleoptera from the herning stadial in central england and eastern germany suggest similarly cold and continental climates during the brorup interstadial and the odderade interstadial the botanical evidence suggests that the minimum mean july temperatures rose to 15 16 c but during the coldest month these temperatures show a gradient between 13 c in the east and 5 c in the west 1998 john wiley sons ltd

evolution of the late pleistocene holocene dead sea basin from sequence statigraphy of fan deltas and lake level reconstruction patterns of sediment transport to the dead sea basin during late pleistocene and holocene times were evaluated by comparing previously established lake levels with patterns of transgressions and regressions in fan deltas at the lake margins while the lake level history reflects the hydrological regime in the drainage basin the transgression regression patterns reflect the response of the clastic sediment transport to the regional hydrology and morphology of the basin by using the two techniques we are able to demonstrate the time relationship between the factors controlling the deposition six sequences are exposed at the western margins of the basin their chronology was obtained by u th radiocarbon and luminescence ages on aragonite and quartz sand from the samra lisan and ze elim formations which cover the past 160 ka our data shows a lag between periods of high water inflow and clastic sediment flux to the basin during highstands the sediments were stored in deep 100 200 m long estuaries that formed in incised canyons into the east and west bounding escarpments during lake level falls the stored sediments were flushed out forming prograding lowstand fan deltas this leads to a high sediment flux during early stages of arid conditions following extreme high lake levels

eemian and holocene sea surface conditions in the southern black sea organic walled dinoflagellate cyst record from core 22 gc3 in order to compare the sea surface conditions in the black sea during the holocene and eemian sapropelic parts of marine core 22 gc3 42 13 53 n 36 29 55 e 838 m water depth were studied for organic walled dinoflagellate cyst content the record shows a change from freshwater brackish assemblages pyxidinopsis psilata spiniferites cruciformis and caspidinium rugosum to more marine assemblages lingulodinium machaerophorum and spiniferites ramosus complex during each interglacial due to the inflow of saline mediterranean water the lacustrine marine transitions in 22 gc3 occurred at 8 3 cal kyr bp during the early holocene and 128 kyr bp during the early eemian slightly later compared to the onset of interglacial conditions on the adjacent land dinoflagellate cyst assemblages reveal higher sea surface salinity 28 30 e g spiniferites pachydermus bitectatodinium tepikiense and spiniferites mirabilis around 126 5 121 kyr bp in comparison to the holocene 15 20 as well as relatively high sea surface temperature e g tuberculodinium vancampoae s pachydermus and s mirabilis especially at 127 6 125 3 kyr bp establishment of high sea surface salinity during the eemian correlates very well with reconstructed relatively high global sea level and is explained as a combined effect of increased mediterranean supply and high temperatures at the beginning of the last interglacial the observed changes in the dinocyst record highlight the importance of nutrients for the composition of the eemian and holocene dinocyst assemblages

timing and climatic impact of greenland interstadials recorded in stalagmites from northern turkey a 50 kyr long exceptionally well dated and highly resolved stalagmite oxygen 18o and carbon 13c isotope record from sofular cave in northwestern turkey helps to further improve the dating of greenland interstadials gi 1 and 3 12 timing of most gi in the sofular record is consistent within 10 to 300 years with the iconic hulu cave record larger divergences 500 years between sofular and hulu are only observed for gi 4 and 7 the sofular record differs from the most recent ngrip chronology by up to several centuries whereas age offsets do not increase systematically with depth the sofular record also reveals a rapid and sensitive climate and ecosystem response in the eastern mediterranean to gi whereas a phase lag of 100 years between climate and full ecosystem response is evident finally results of spectral analyses of the sofular isotope records do not support a 1 470 year pacing of gi

evidence for last interglacial chronology and environmental change from southern europe establishing phase relationships between earth system components during periods of rapid global change is vital to understanding the underlying processes it requires records of each component with independent and accurate chronologies until now no continental record extending from the present to the penultimate glacial had such a chronology to our knowledge here we present such a record from the annually laminated sediments of lago grande di monticchio southern italy using this record we determine the duration 17 70 0 20 ka and age of onset 127 20 1 60 ka b p of the last interglacial as reflected by terrestrial ecosystems this record also reveals that the transitions at the beginning and end of the interglacial spanned only 100 and 150 years respectively comparison with records of other earth system components reveals complex leads and lags during the penultimate deglaciation phase relationships are similar to those during the most recent deglaciation peaks in antarctic warming and atmospheric methane both leading northern hemisphere terrestrial warming it is notable however that there is no evidence at monticchio of a younger dryas like oscillation during the penultimate deglaciation warming into the first major interstadial event after the last interglacial is characterized by markedly different phase relationships to those of the deglaciations warming at monticchio coinciding with antarctic warming and leading the atmospheric methane increase diachroneity is seen at the end of the interglacial several global proxies indicate progressive cooling after 115 ka b p whereas the main terrestrial response in the mediterranean region is abrupt and occurs at 109 50 1 40 ka b p

fire history and the global charcoal database a new tool for hypothesis testing and data exploration version 1 of the global charcoal database is now available for regional fire history reconstructions data exploration hypothesis testing and evaluation of coupled climate vegetation fire model simulations the charcoal database contains over 400 radiocarbon dated records that document changes in charcoal abundance during the late quaternary the aim of this public database is to stimulate cross disciplinary research in fire sciences targeted at an increased understanding of the controls and impacts of natural and anthropogenic fire regimes on centennial to orbital timescales we describe here the data standardization techniques for comparing multiple types of sedimentary charcoal records version 1 of the global charcoal database has been used to characterize global and regional patterns in fire activity since the last glacial maximum recent studies using the charcoal database have explored the relation between climate and fire during periods of rapid climate change including evidence of fire activity during the younger dryas chronozone and during the past two millennia

high rates of sea level rise during the last interglacial period sea level during the last interglacial stood at least 4 m higher than at present with evidence of short term fluctuations of up to 10 m a new continuous sea level record from the red sea and coral ages suggest that during these fluctuations sea level changes were on the order of 1 6 m per century

pleistocene water intrusions from the mediterranean and caspian seas into the black sea the hydrological balance of the black sea is governed by riverine input and by the exchange with the mediterranean sea a speleothem record from a cave in northern turkey that tracks the isotopic signature of black sea surface water suggests an open connection to the mediterranean sea in at least twelve periods in the past 670 000 years

mineralogy geochemistry and the development of ductile shear zones in the grampian slide zone of the scottish central highlands the grampian slide zone comprises a system of shear zones characterized by strain induced syn tectonic muscovitization growth of porphyroblasts of plagioclase garnet and muscovite concordant quartz veinlets and by later tectonic sillimanite and late to post tectonic kyanite traverses across shear zones in the central highland division show progressive modification of original gneissic fabrics demonstrating that metamorphism and gneissification preceded the shearing event mylonitization involved bulk mobilization of alkalies na ca k and trace elements ba rb sr ni cr zr accompanied by decreasing fe oxidation ratios and increasing shearing progressively changed the mineral chemistry of reversely zoned plagioclase zoned garnet and micas advanced syn shearing blastesis produced a suite of lenticular pegmatitic segregation veinlets in the mylonites a coeval suite of larger intrusive pegmatites represents more mobile material that has migrated through the shear zones the pegmatites and the mylonite matrices yield u pb monazite ages of c 806 ma corresponding to the precambrian knoydartian event in the moine rocks of the northern highlands the shear zones record compressional transport directed towards the nne and in the northern sector of the central highlands were reactivated by later caledonian extensional se directed movement the presence of the c 806 ma event in the grampian group challenges recent proposals that early deformation across the entire dalradian supergroup can be correlated with the c 590 ma tay nappe

circum mediterranean fire activity and climate changes during the mid holocene environmental transition 8500 2500 cal bp a mid to late holocene synthesis of fire activity from the mediterranean basin explores the linkages among fire climate variability and seasonality through several climatic and ecological transitions regional fire histories were created from 36 radiocarbon dated sedimentary charcoal records available from the global charcoal database during the mid holocene thermal maximum around 7500 4500 cal bp charcoal records from the northern mediterranean suggest an increase in fire while records from the southern mediterranean indicate a decrease associated with wetter than present summers a north south partition between 40 and 43 n latitude is apparent in the central and western mediterranean relatively abrupt changes in fire activity are observed c 5500 5000 cal bp records of holocene fire activity appear sensitive to both orbitally forced climate changes and shorter lived excursions which may be related to north atlantic cold events possibly modulated by an nao like climate mechanism in cases wh

last interglacial palaeovegetation palaeoenvironments and chronology a new record from lago grande di monticchio southern italy abstract the sediments of lago grande di monticchio southern italy extend continuously from the present back to the penultimate glacial stage and have an independent lamination based chronology of high precision and accuracy results are presented here from a detailed palynological investigation of that part of the sediment sequence that extends from the last millennia of the penultimate glacial stage to the first stadial following the last interglacial li quantitative palaeovegetation and palaeoclimate reconstructions made from the palynological data are also presented the onset of the li is dated to 127 20 ka bp a date that is consistent with other recent estimates the duration of the li is estimated to have been 17 70 ka the palaeovegetation record indicates a transition period of 3 35 ka at the end of the penultimate glacial stage prior to the onset of the li no younger dryas like oscillation is recorded although the transition was interrupted by a brief event lasting ca 250 years during which pollen of woody taxa was reduced in abundance steppe vegetation dominated during the latter part of the penultimate full glacial stage but was replaced progressively by wooded steppe during the transition although the development of forest cover marked the onset of the li the forests were relatively open or discontinuous during the first 2 65 ka closing progressively thereafter and generally dominating between 123 00 and 109 50 ka bp the end of the li is dated to 109 50 ka bp after which date forest cover became discontinuous and wooded steppe or steppe dominated during the 1 90 ka of the subsequent stadial as might be expected given the location of the lake the composition of the li forests differs markedly from those recorded from northern europe as well as from those recorded at other localities in southern europe the palaeoclimate reconstructions reveal complex changes in seasonality the maximum coldest month mean temperatures being between 125 70 ka bp and 123 00 ka bp whereas maxima for both annual temperature sum and the ratio of actual to potential evapotranspiration were between 120 60 ka bp and 115 80 ka bp reconstructed zonal mean values for all three climatic variables in the zones in which they peak exceed values at the locality today comparison with other palaeovegetation records of the li from europe reveals that forest cover generally opened up north of the alpine region probably ca 115 ka bp coinciding with a marked decrease in sea surface temperatures in the nordic seas this probably corresponds to a marked shift in forest composition at lago grande di monticchio at 115 80 ka bp with an associated reconstructed decrease of ca 5 c in coldest month mean temperature nonetheless forest continued to dominate at lago grande di monticchio until 109 50 ka bp such comparisons also reveal considerable complexity in the geographical and altitudinal patterns of change in palaeovegetation during the li such complexity is to be expected given the parallel complexity of holocene changes systematic comparisons between reconstructions of palaeoclimate are hampered by a lack of consistency in approach and in the variables reconstructed further insight into this complexity of palaeoclimate development during the li requires a synthesis of the available data and application of a consistent reconstruction approach that also provides robust estimates of the uncertainty in the reconstructed values

isotopic paleolimnology of lake kinneret the carbonate organic c and n contents and their respective d 13 c were measured in four cores from lake kinneret israel using these data and the isotopic difference between coexisting carbonate and organic c dd 13 c we attempted to reconstruct the lake s productivity and regional climatic conditions during the late holocene the sedimentary record of the last 120 yr for which climatological data are available demonstrates that during periods of intense productivity organic c content and its d 13 corg are high whereas the dd 13 c values are low during wet periods characterized by intense input of particulates and nutrients from external sources the caco 3 content its d 13 ccar and d 18 ocar and the organic c n ratios are low based on these correlations the longer sedimentary record of the last ca 3 300 yr was divided into five stages which differ in productivity and or climatic characteristics this longer sedimentary record indicates that the primary production in lake kinneret has varied in the past over a range similar to that observed presently but the rate of these changes was much slower the rainiest period recorded in the sediments was from about 200 b c t oa d 200 i e during the roman period when the region was heavily populated the recent decrease in d 13 c of atmospheric co2 that accompanies the global anthropogenic co2 rise seems to be recorded by a commensurate decrease in d 13 ccar of the sediments the concomitant increase in dd 13 c expresses an increase in the isotopic fractionation of the lake s primary producers which may also be related to the atmospheric co2 rise

the late quaternary limnological history of lake kinneret sea of galilee israel the freshwater lake kinneret sea of galilee and the hypersaline dead sea are remnant lakes evolved from ancient water bodies that filled the tectonic depressions along the dead sea transform dst during the neogene quartenary periods we reconstructed the limnological history level and composition of lake kinneret during the past 40 000 years and compared it with the history of the contemporaneous lake lisan from the aspect of the regional and global climate history the lake level reconstruction was achieved through a chronological and sedimentological investigation of exposed sedimentary sections in the kinnarot basin trenches and cores drilled at the ohalo ii archeological site shoreline chronology was established by radiocarbon dating of organic remains and of melanopsis shells the major changes in lake kinneret level were synchronous with those of the southern lake lisan both lakes dropped significantly 42 000 30 000 23 800 and 13 000 yr ago and rose 39 000 26 000 5000 and 1600 yr ago between 26 000 and 24 000 yr ago the lakes merged into a unified water body and lake level achieved its maximum stand of 170 m below mean sea level m bsl nevertheless the fresh and saline water properties of lake kinneret and lake lisan respectively have been preserved throughout the 40 000 years studied calcium carbonate was always deposited as calcite in lake kinneret and as aragonite in lake lisan dead sea indicating that the dead sea brine which supports aragonite production never reached or affected lake kinneret even during the period of lake high stand and convergence the synchronous level fluctuation of lakes kinneret lisan and the holocene dead sea is consistent with the dominance of the atlantic mediterranean rain system on the catchment of the basin and the regional hydrology the major drops in lake kinneret lisan levels coincide with the timing of cold spells in the north atlantic that caused a shut down of rains in the east mediterranean and the lakes drainage area d 2004 university of washington all rights reserved

increasing vegetation and climate gradient in western europe over the last glacial inception 122 110 ka data model comparison high resolution terrestrial pollen and marine planktic and benthic isotopes coarse fraction and n pachyderma s analyses have been performed in the marine isotope stage mis 5 interval of images core md99 2331 retrieved in the northwestern iberian margin this study shows the occurrence of a zeifen interstadial stadial succession on land and in the ocean during the first part of mis 5e in northwestern iberia the eemian is marked from 126 to 122 ka by the development of deciduous quercus forest at the same time as mediterranean forest colonised southern iberia and deciduous quercus corylus forest occupied northernmost european regions from 121 to 115 ka carpinus betulus forest developed in nw iberia indicating a winter cooling by 2degreesc on land and an increase in annual precipitation by 100 200 min along with a sea surface temperature sst decreasing trend off iberia a similar cooling has been documented at the same time in northern germany 52degreesn by the replacement of deciduous forest by coniferous abies picea formations implying a southward displacement of the deciduous tree line between similar to60degreesn and 50degreesn as early as 120 ka the southward migration of the tree line between 72degreesn and 58degreesn simulated by the earth model of intermediate complexity mobidic from 122 and 120 ka and considered as a major process to initiate the last glaciation is therefore compatible with data between 115 and 110 ka the substantial ice accumulation in northern high latitudes mis 5e 5d transition was synchronous with successive drops c26 and c25 in northeastern atlantic sst in northwestern iberia abies pinus trees developed at the expense of quercus carpinus forest a tundra like environment occupied northern germany marking the end of the interglacial in northwestern europe at 115 ka and boreal forest likely colonised northeastern france the first displacement of the vegetation belts at 121 ka was enhanced at 115 ka indicating an amplification of the vegetation and climate gradients in northeastern atlantic and european borderlands probably related with the well developed ice caps at that time the comparison between the general trend in the estimated and simulated mobidic winter and summer temperatures for latitudes between 35 and 45degreesn shows that both follow quite straightforwardly the precession signal although the simulated and reconstructed temperatures agree better in the south than north of 40degreesn annual precipitation is exhibiting opposite trend in the data and in the model this contradiction is likely the fact that the zonal climate simulated by the model may not accurately represent the regional climate features as reconstructed from the pollen c 2004 elsevier b v all rights reserved

stable isotope compositions of speleothems from the last interglacial spatial patterns of climate fluctuations in europe abstract studies on the last interglacial lig can provide information on how our environment behaved in a period of slightly higher global temperatures at about 125 4 ka even if it is not the best analogue for the holocene the available lig climate proxy records are usually better preserved and can be studied at a higher resolution than those of the preceding interglacials allowing detailed comparisons this paper presents complex stable hydrogen carbon and oxygen isotope records obtained for carbonate 13 c and 18 o carb and fluid inclusion hosted water d and 18 o w of a stalagmite from the baradla cave system in central europe that covers most of the lig as proven by u th dates comparing its c and o isotope data with records reported for other speleothem cave hosted carbonate deposits from europe revealed the complex behavior of these climate proxies with a concerted relative increase in 18 o of carbonates from 128 to 120 ka and synchronized shifts in the opposite direction after 119 ka the hydrogen isotope analyses of inclusion hosted water extracted from the bar ii stalagmite also correspond to the regional climate proxy records with meaningful deviations from global temperature trends beside following the general paleotemperature pattern from the climate optimum high d values up to 64 around 120 ka to the subsequent cooling starting at about 119 ka low d values down to 90 at about 109 ka a period between 126 5 and 123 ka with low d values down to 81 is detected in the bar ii stalagmite although the isotope shifts are muted in the c o isotope data of carbonate due to competitive fractionation processes the 13 c data show a positive relationship with the d pattern indicating humidity and possibly temperature variations the periods with low d values fit well to temperature and humidity changes inferred from proxy records from western europe to the eastern mediterranean spatial distributions of these variables show that at about 125 2 ka the mediterranean region was characterized by warm humid conditions and enhanced seasonality with elevated winter precipitation the combined interpretation of stable isotope data revealed that the alpine and mediterranean regions behaved differently during greenland stadial 26 gs26 119 to 116 2 ka while the alpine records fluctuated in close agreement with the central greenland ice core 18 o data the bar ii stalagmite show a positive 18 o carb anomaly the baradla data indicate enhanced aridity and seasonality for a part of gs26 with the relative dominance of summer precipitation and mediterranean moisture contribution following the gs26 event the effect of long term global cooling becomes dominant in the baradla isotope records and leads to glacial inception at about 109 ka

controlling factors on a paleo lake oxygen isotope record yammouneh lebanon since the last glacial maximum abstract late quaternary paleoclimatic changes in the levant are difficult to extract from carbonate oxygen isotope records partly because the factors controlling the terrestrial 18 o signals are not fully understood in this region characterized by sharp climatic gradients here we address this purpose by presenting the first 14 c dated isotope record from the northern levant the record is based on oxygen isotopes from ostracod shells from lacustrine palustrine deposits accumulated in a small karstic hydrologically open basin yammouneh located on the eastern flank of mount lebanon we have first constructed a composite isotopic record obtained from three different ostracod taxa this yields an oxygen isotope record of ostracods ost related to the most widespread species ilyocypris inermis and converted to 18 o values coeval with calcite precipitated in equilibrium c with the lake water l as with other records from the mediterranean region the yammouneh profile shows maximum and minimum c values during the lgm and the early holocene respectively and a slight late holocene increase in order to discuss the potential causes of the observed 18 o values fluctuations e g changes in the isotopic composition of the moisture source temperature precipitation minus evaporation p e balance or atmospheric circulation we tentatively reconstruct the lake water isotope composition by correcting the c values for lake water temperature using regional paleotemperature estimates inferred l values were then corrected for the isotopic composition of the eastern mediterranean sea surface water the moisture source derived from planktonic foraminifera 18 o values corrected for alkenone based sea surface temperature our study suggests that holocene l fluctuations are primarily linked to changes in the sea surface water composition source effect amplified by enhanced inland rainfall during the early holocene during the lgm low l values at yammouneh are likely due to the ground temperature effect on the rainfall isotope composition possibly associated with a steeper altitudinal thermal gradient inland and with changes in air mass trajectories over the mediterranean sea

high resolution palynological record off the iberian margin direct land sea correlation for the last interglacial complex abstract we present high resolution pollen dinocyst and isotopic data for the last interglacial complex from marine core md952042 southwestern margin of the iberian peninsula 37 48 n 10 10 w 3148 m direct land sea correlation from this core indicates that during this period north atlantic sea surface temperatures were in phase with iberian climate our palynological analysis suggests a younger dryas like event at the marine isotope stage mis 6 5 transition the analysis also indicates that the eemian spans from the lightest isotopic values of mis 5e ca 126 ky bp to the heavier isotopic values towards the mis 5e 5d transition therefore the eemian is not entirely equivalent to mis 5e pollen analysis identifies four climatic phases of low amplitude during the eemian a mediterranean climate in southwestern europe is gradually replaced by oceanic conditions the middle of the eemian is characterized by an increase in precipitation on the land and ocean associated with a slight cooling this seems to be the result of a displacement of the polar front as far south as southern europe during this period after the eemian three relatively short climatic phases on land melisey i st germain ia and montaigu cold event occurred contemporaneously with three shifts of sea surface temperatures the montaigu event first identified in terrestrial pollen sequences is therefore also recorded in core md952042 on the basis of pollen dinocyst and planktonic isotopic data our results also show that the warm periods of mis 5 are not characterized by similar climatic conditions on land

charcoal and fly ash particles from lake lucerne sediments central switzerland characterized by image analysis anthropologic stratigraphic and environmental implications abstract in order to link the charcoal record from sedimentary archives with the combustion processes that reflect past anthropogenic activity a novel method based on automated image analysis was developed it allows a detailed quantification and morphological analysis of the combustion derived products that were emitted in the area of lake lucerne central europe throughout the last 7200 years charcoal particle distribution reconstructed from the composite sedimentary record shows that the charcoal input is primarily linked to redistribution of detrital m size charcoal degradation products from surface runoff into the large lake basin however the independent distribution of the coarser charcoal fraction 38 m exhibits four major periods of large scale fire activity around 5500 3300 2400 and 530 cal bp these events are synchronous with major anthropogenic changes lake dwellings land use changes technological innovations although it is possible that these major fire episodes could have been indirectly triggered by climatic deterioration and unfavorable environmental conditions during the late nineteenth century a great increase in slag particles and magnetic spherules of fly ash occurred due to the steamboat navigation on lake lucerne the successive burning of wood after ad 1838 coal after ad 1862 and diesel after ad 1931 by the steamboat traffic produced specific particle shapes providing valuable chronological markers for dating the recent sediments and a proxy for fossil fuel combustion

the last climatic cycle at kopais central greece thick lacustrine sequences from southern europe provide an opportunity to derive continuous records where the chronostratigraphical position of pre holocene stages can be determined with increased confidence here high resolution sediment and pollen analytical results from a 60 m core recovered from the kopais basin central greece spanning the interval from the last interglacial to the early holocene are presented the record shows distinct shifts between open vegetation periods of increased erosion with sediment inwashing and forest periods associated with calcite precipitation in the lake the sequence of major events of the last climatic cycle contained at kopais bears strong similarities to other records in greece but also reveals the presence of high frequency oscillations with higher amplitudes than previously seen at other sites

oceanography of the black sea a review of some recent results abstract a new synthesis of the black sea oceanography is presented primarily based on studies carried out in the southern black sea as well as on some recent work covering the entire basin obtained in a new era of increasing cooperation between the riparian countries a review of the physical environment is given seasonal and interannual climatic variability of the system are discussed in relation to its hydrology water mass variability and formation are studied with emphasis on the inflow of mediterranean waters pycnocline variability shelf and internal mixing and double diffusive convection the general circulation of the basin and the roles of stratification topography and coastline variations in determining the behaviour of the rapid unstable boundary currents and upwelling along the coast are discussed based on hydrographic data and satellite observations impacts of the physical processes on the ecosystem are discussed

fire climate and the origins of agriculture micro charcoal records of biomass burning during the last glacial interglacial transition in southwest asia this study investigates changes in climate vegetation wildfire and human activity in southwest asia during the transition to neolithic agriculture between ca 16 and ca 9 ka in order to trace the fire history of this region we use microscopic charcoal from lake sediment sequences and present two new records one from south central turkey akgol and the other from the southern levant hula these are interpreted primarily as the result of regional scale fire events with the exception of a single large event ca 13 ka at akgol which phytolith analysis shows was the result of burning of the local marsh vegetation comparison between these and other regional micro charcoal stable isotope and pollen records shows that wildfires were least frequent when the climate was cold and dry glacial lateglacial stadial and the vegetation dominated by chenopod artemisia steppe and that they became more frequent and or bigger at times of warmer wetter but seasonally dry climate lateglacial interstadial early holocene warmer and wetter climates caused an increase in biomass availability with woody matter appearing to provide the main fuel source in sites from the levant while grass fires predominated in the interior uplands of anatolia southwest asia s grasslands reached their greatest extent during the early holocene and they were maintained by dry season burning that helped to delay the spread of woodland by up to 3 ka at the same time as neolithic settlement became established across this grass parkland landscape although climatic changes appear to have acted as the principal pacemaker for fire activity through the last glacial interglacial climatic transition lgit human actions may have amplified shifts in biomass burning fire regimes therefore changed markedly during this time period and both influenced and were influenced by the cultural economic transition from hunter foraging to agriculture and village life copyright 2009 john wiley sons ltd

a long pollen record from lac du bouchet massif central france for the period ca 325 to 100 ka bp ois 9c to ois 5e abstract pollen analysis was carried out on sediments older than the wurm pleniglacial ois 4 in two new sequences h and i derived from the centre of lac du bouchet massif central the inferred vegetation history enables for the first time in france five temperate episodes to be defined which pre date the last interglacial these temperate episodes alternate with episodes during which the changes in vegetation are indicative of glacial climates comparison of these climatic episodes with the oceanic isotope record shows that the pollen record of sequences h and i from lac du bouchet spans the time interval from ois 9c ussel interstadial to ois 5e ribains eemian interglacial in the organic sediments from the amargiers interstadial ois 9a a trachytic layer ar ar dated to ca 275 ka enables a correlation to be established with the upper part of a sequence derived from the nearby praclaux crater the lower part of this sequence being of holsteinian age ois 11c the cross dating of the pollen sequences from lac du bouchet cores h i and d and from praclaux provides a complete record from the massif central southern france of successive glacial and interglacial episodes that span the last ca 400 ka that is the interval from the holsteinian to the holocene

the last climatic cycle at la grande pile vosges france a new pollen profile a new pollen diagram has been made from an old unanalyzed core from la grande pile gp xx correlations with the previous work of woillard 1975 1978 leads to the following conclusions the end of the eemian was marked by a minor climatic change prior to the melisey i stadial the ognon ii and ognon iii interstadials are not consistent and correspond to the level of reworking of mesophilous taxa during the last pleniglacial the limitations of the botanical interpretation of pollen spectra from the last pleniglacial are underlined lastly bruckenthalia and larix are identified for the first time at la grande pile the respective roles of these taxa following the eemian are additional arguments for correlating the st germain i and ii with the early weichsel interstadials in the north of middle europe

holocene climate variability and cultural evolution in the near east from the dead sea sedimentary record abstract a comprehensive record of lake level changes in the dead sea has been reconstructed using multiple well dated sediment cores recovered from the dead sea shore interpreting the lake level changes as monitors of precipitation in the dead sea drainage area and the regional eastern mediterranean palaeoclimate we document the presence of two major wet phases 10 8 6 and 5 6 3 5 cal kyr bp and multiple abrupt arid events during the holocene the arid events in the holocene dead sea appear to coincide with major breaks in the near east cultural evolution at 8 6 8 2 4 2 3 5 cal kyr bp wetter periods are marked by the enlargement of smaller settlements and growth of farming communities in desert regions suggesting a parallelism between climate and near east cultural development

north atlantic current and european environments during the declining stage of the last interglacial this paper provides a tentative reconstruction of environmental shifts in europe associated with changes of the north atlantic current and related meridional sea surface temperature sst gradients during most of the eemian interglacial ca 126 115 ka the north atlantic current extended far north into the nordic seas and european environments were comparable to those of the holocene however ca 115 ka an sst drop in the nordic seas marked a southward displacement of the north atlantic current this hydrographic shift was associated with substantial cooling in northern europe and drier conditions in the mediterranean region the polar timberline retreated southward from 69 n in northernmost scandinavia to 52 n in central europe and thermophilous deciduous trees became extinct north of the 48th parallel woodlands persisted in southern europe for another 5 k y well into marine isotope substage 5d these conditions indicate steep vegetation and climate gradients at the inception of the last glacial

a 750 year fire history based on lake sediment records in central yellowstone national park usa a 750 year fire history was reconstructed for the central plateau of yellowstone national park from the deep water sediments of five lakes the charcoal record from a large lake provided a chronology of regional fires data from four small lakes were used to study local and extralocal fires the co occurrence of abundant charcoal and high magnetic susceptibility values at the same stratigraphic level was used as evidence of a local catchment fire and a charcoal peak without high magnetic susceptibility was ascribed to an extralocal fire or a local fire without a related erosion event the fire history was compared with the dendrochronologic fire record for the last 450 years and the close agreement provided the justification to extend the chronology back in time large areas of the region burned in ad 1988 c 1700 c 1560 and c 1440 from c 1220 to 1440 and c 1700 to 1987 intermediate to small areas burned the near absence of fires in the twentieth century prior to the large fires of 1988 is evi

a model of pollen source area for an entire lake surface a model of pollen deposition on the surface of an entire basin is developed to estimate pollen source area and results are compared with those for a point at the center of a basin i c prentice 1985 quaternary research 23 76 86 1988 vegetation history pp 17 42 kluwer academic this model is more appropriate for approximating the source area of pollen in lake sediment since mixing in lake water and focusing of sediment redistribute pollen originally deposited over the entire surface in general the pollen source radius for the entire basin surface is 10 30 smaller than the source radius for a point at the center the difference in the source radius is more profound for heavier pollen types such as spruce and sugar maple than for lighter types such as oak and ragweed the average pollen input to the entire surface is more strongly influenced by nearby pollen sources than pollen deposition at the center the pollen record from a lake may therefore provide different spatial resolution than the record from a bog of similar radius

dynamics of the laschamp geomagnetic excursion from black sea sediments abstract investigated sediment cores from the southeastern black sea provide a high resolution record from mid latitudes of the laschamp geomagnetic polarity excursion age constraints are provided by 16 ams 14c ages identification of the campanian ignimbrite tephra 39 28 0 11 ka and by detailed tuning of sedimentologic parameters of the black sea sediments to the oxygen isotope record from the greenland ngrip ice core according to the derived age model virtual geomagnetic pole vgp positions during the laschamp excursion persisted in antarctica for an estimated 440 yr making the laschamp excursion a short lived event with fully reversed polarity directions the reversed phase centred at 41 0 ka is associated with a significant field intensity recovery to 20 of the preceding strong field maximum at 50 ka recorded field reversals of the laschamp excursion lasting only an estimated 250 yr are characterized by low relative paleointensities 5 relative to 50 ka the central fully reversed phase of the laschamp excursion is bracketed by vgp excursions to the sargasso sea 41 9 ka and to the labrador sea 39 6 ka paleomagnetic results from the black sea are in excellent agreement with vgp data from the french type locality which facilitates the chronological ordering of the non superposed lavas that crop out at laschamp olby in addition vgps between 34 and 35 ka reach low northerly to equatorial latitudes during a clockwise loop inferred to be the mono lake excursion

substantial contribution to sea level rise during the last interglacial from the greenland ice sheet during the last interglacial period the eemian global sea level was at least three metres and probably more than five metres higher than at present1 2 complete melting of either the west antarctic ice sheet or the greenland ice sheet would today raise sea levels by 6 7 metres but the high sea levels during the last interglacial period have been proposed to result mainly from disintegration of the west antarctic ice sheet3 with model studies attributing only 1 2 m of sea level rise to meltwater from greenland4 5 this result was considered consistent with ice core evidence4 although earlier work had suggested a much reduced greenland ice sheet during the last interglacial period6 here we reconsider the eemian evolution of the greenland ice sheet by combining numerical modelling with insights obtained from recent central greenland ice core analyses our results suggest that the greenland ice sheet was considerably smaller and steeper during the eemian and plausibly contributed 4 5 5 m to the sea level highstand during that period we conclude that the high sea level during the last interglacial period most probably included a large contribution from greenland meltwater and therefore should not be interpreted as evidence for a significant reduction of the west antarctic ice sheet

north atlantic control on precipitation pattern in the eastern mediterranean black sea region during the last glacial based on proxy records from western black sea cores we provide a comprehensive study of climate change during the last glacial maximum and late glacial period in the black sea region for the first time we present a record of relative changes in precipitation for nw anatolia based on variations in the terrigenous supply expressed as detrital carbonate concentration the good correspondence between reconstructed rainfall intensity in nw anatolia and past western mediterranean sea surface temperatures ssts implies that during the glacial period the precipitation variability was controlled like today by mediterranean cyclonic disturbances periods of reduced precipitation correlate well with low ssts in the mediterranean related to heinrich events h1 and h2 stable oxygen isotopes and lithological and mineralogical data point to a significant modification in the dominant freshwater sediment source concomitant to the meltwater inflow after 16 4 cal ka bp this change implies intensification of the northern sediment source and with other records from the mediterranean region consistently suggests a reorganization of the atmospheric circulation pattern affecting the hydrology of the european continent the early deglacial northward retreat of both atmospheric and oceanic polar fronts was responsible for the warming in the mediterranean region leading simultaneously to more humid conditions in central and northern europe

23 000 yr of vegetation history of the upper lerma a tropical high altitude basin in central mexico abstract pollen analysis on a 9 54 m sediment core from lake chignahuapan in the upper lerma basin the highest intermontane basin in central mexico 2570 m asl documents vegetation and limnological changes over the past 23 000 14c yr the core was drilled near the archaeological site of santa cruz atizapan a site with a long history of human occupation abandoned at the end of the epiclassic period ca 900 ad six radiocarbon ams dates and two well dated volcanic events the upper toluca pumice with an age of 11 600 14c yr b p and the tres cruces tephra of 8500 14c yr b p provide the chronological framework for the lacustrine sequence from ca 23 000 14c yr b p to ca 11 600 14c yr b p the plant communities were woodlands and grasslands based on the pollen data the glacial advances mii 1 and mii 2 correlate with abundant non arboreal pollen mainly grasses from ca 21 000 to 16 000 14c yr b p and at ca 12 600 14c yr b p during the late pleistocene lake chignahuapan was a shallow freshwater lake with a phase of lower level between 19 000 and 16 000 14c yr b p after 10 000 14c yr b p tree cover in the area increased and a more variable lake level is documented late holocene ca 3100 14c yr b p deforestation was concurrent with human population expansion at the beginning of the formative period 1500 b c agriculture and manipulation of the lacustrine environment by human lakeshore populations appear at 1200 14c yr b p 550 a d with the appearance of zea mays pollen and abundant charcoal particles

climate deterioration in the eastern mediterranean as revealed by ion microprobe analysis of a speleothem that grew from 2 2 to 0 9 ka in soreq cave israel abstract analysis of oxygen isotope ratios 18 o by ion microprobe resolves a sub annual climate record for the eastern mediterranean from a soreq cave stalagmite that grew between 2 2 and 0 9 ka in contrast to conventional drill sampling methods that yield a total variation of 1 0 in 18 o calcite values across our sample the methods described here reveal up to 2 15 variation within single annual growth bands values of 18 o measured by ion microprobe vary in a regular saw tooth pattern that correlates with annual fluorescent growth banding where calcite grades from light to dark fluorescence modern records of precipitation and of cave dripwater indicate that variable 18 o calcite values record regular seasonal differences in 18 o rainfall modified by mixing in the vadose zone large differences in 18 o values measured across a single band i e between the dark and light fluorescent calcite or 18 o dark light are interpreted to indicate wetter years while smaller differences represent drier years oxygen isotopes record 1 month scale growth increments 2 changes in 18 o dark light that represent seasonality 3 a systematic long term decrease in maximum 18 o dark light values and 4 an overall increase in average 18 o calcite values through time these results suggest a drying of regional climate that coincides with the decline of the roman and byzantine empires in the levant region