effect of subtropical mode water on the decadal variability of the subsurface transport through the luzon strait in the western pacific ocean analysis of the 62 year hindcast outputs from an eddy resolving ocean general circulation model shows a good correspondence of the luzon strait subsurface transport to the pacific decadal oscillation pdo index on a decadal time scale with the latter leading by about 5 years the backward particle tracing experiments indicate that the part of the subsurface water in the luzon strait generated by the subduction processes comes from the subtropical mode water stmw the model results also show a strong pdo signal in the subduction rate as well as the subsurface low potential vorticity pv in the formation region of the stmw and these decadal signals can be traced all the way to the luzon strait as pv anomalies follow the subtropical gyre circulation in about 5 years the pv anomalies from the stmw affect the subsurface net transport in the luzon strait through changing the subsurface density structure and then zonal velocity

uranium series ages of travertines and timing of the last glaciation in the northern yellowstone area wyoming montana uranium series age determinations by mass spectrometric methods were done for travertines and associated carbonate veins related to clastic deposits of the last glaciation pinedale in the northern yellowstone area dramatic variations in the hydrologic head are inferred from variations in the elevation of travertine deposition with time and are consistent with the expected hydrologic effects of glaciation we determine the following chronology of the pinedale glaciation with the key assumption that travertine deposits and associated carbonate veins perched high above present thermal springs were deposited when glaciers filled the valley below these perched deposits 1 the early pinedale outlet glacier advanced well downvalley between 47 000 and 34 000 yr b p 2 the outlet glacier receded to an interstadial position between 34 000 and 30 000 yr b p 3 an extensive pinedale ice advance occurred between 30 000 and 22 500 yr b p 4 a major recession occurred between 22 500 and 19 500 yr b p 5 a minor readvance deckard flats culminated after 19 500 yr b p and 6 recession from the deckard flats position was completed before 15 500 yr b p this chronology is consistent with the general trend of climatic changes in the northern hemisphere as revealed by recent high resolution ice core records from the greenland ice sheet

multidecadal oceanographic changes in the western pacific detected through high resolution bomb derived radiocarbon measurements on corals high resolution measurements of radiocarbon 14c in corals can be used to reconstruct past variability in ocean conditions here we report seasonal 14c changes in coral from ishigaki island japan and compare with previously reported data from palau and guam our data clearly indicate a significant increase in 14c from 1947 to 1998 related to atmospheric nuclear bomb testing the three early 14c spikes related to the atmospheric nuclear bomb tests in the us proving grounds at bikini and enewerak atoll conducted in 1954 1956 and 1958 were detected from the ishigaki coral after 1976 variability in the mindanao dome region related to north equatorial current nec bifurcation latitude migration affected the 14c difference between palau and guam whereas the difference between ishigaki and guam was not correlated with the bifurcation latitude the 14c difference between ishigaki and guam may be due to mesoscale eddies in the kuroshio area on the decadal scale the northward shift of nec bifurcation latitude after 1976 the year as known as pacific decadal oscillation regime shift from negative to positive was concurrent with the abundant westward propagating mesoscale eddies in the subtropical countercurrent region and stronger kuroshio transport off the east taiwan which may be represented by a smaller 14c difference between ishigaki and guam after 1976

uranium series dating of pedogenic silica and carbonate crater flat nevada a 230th 234u 238u dating study on pedogenic silica carbonate clast rinds and matrix laminae from alluvium in crater flat nevada was conducted using small sample thermal ionization mass spectrometry tims analyses on a large suite of samples though the 232th content of these soils is not particularly low mostly 0 1 9 ppm the high u content of the silica component mostly 4 26 ppm makes them particularly suitable for 230th u dating on single 10 to 200 mg totally digested samples using tims we observed that 1 both micro within rind and macro stratigraphic mappable deposit order of the 230th u ages were preserved in all cases 2 back calculated initial 234u 238u fall in a restricted range typically 1 67 0 19 so that 234u 238u ages with errors of about 100 kyr 2 could be reliably determined for the oldest 400 to 1000 ka rinds and 3 though 13 of the samples were 350 ka only three showed evidence for an open system history even though the sensitivity of such old samples to isotopic disruption is very high an attempt to use leach residue techniques to separate pedogenic from detrital u and th failed yielding corrupt 230th u ages we conclude that 230th u ages determined from totally dissolved multiple sub mm size subsamples provide more reliable estimates of soil chronology than methods employing larger samples chemical enhancement of 238u 232th or isochrons

multidecadal changes of upper ocean thermal conditions in the tropical northwest pacific ocean versus south china sea during 1960 2015 abstractby analyzing the upper ocean properties of observation based hydrographic data and validated oceanic reanalysis products this study presents multidecadal changes of oceanic surface and sub

u th dating of striated fault planes direct dating of brittle fault activity is of fundamental importance to tectonic reconstructions and paleoseismic studies one way to address this issue is by constraining the timing of fault striations but this requires a better understanding of the striation formation mechanism and associated mineralization we present results from a microstructural geochemical and geochronological study of calcite precipitates associated with striated fault planes from the dead sea fault zone in northern israel we recognize four types of coexisting calcite precipitates including calcite cement in dilation breccia calcite in striated groove morphology calcite gouge associated with hydraulic fracturing and pressure solution and calcite coating of the fault surface carbon oxygen isotopes 87sr 86sr ratios and rare earth element and yttrium rey patterns indicate various precipitation mechanisms associated with formation of syntectonic calcite cement and striations coseismic calcite gouge and interseismic calcite coating precipitates in the fault zone using u th dating of samples from three adjacent fault planes we delineate four welldefined deformation ages in the period from 220 to 60 ka we conclude that these ages constrain the timing of activity along the dead sea fault zone in northern israel and argue that a similar methodological approach could potentially shed light on the timing of deformation in other brittle fault zones

comparison of the quaternary travertine sites in the denizli extensional basin based on their depositional and geochemical data abstract in the denizli basin turkey located in the western anatolian extensional province travertine and tufa deposition has been an ongoing process for at least 600 000 years travertine bodies which are 30 to 75 m thick and each covers areas of 1 to 34 km2 are up to 1 km3 in volume today spring waters in this area have temperatures of 19 to 57 c are of the ca mg hco3 so4 type in the pamukkale kelkaya and pinarbasi areas and the ca mg so4 hco3 type at cukurbag thermal waters along the northern margin of the basin are generally hotter than those in the east southeast and south the 18o and d values of the spring waters indicate a meteoric origin the average temperatures of the hydrothermal systems in the denizli basin appear to have decreased from pleistocene to holocene travertine which formed from the hotter water is more widespread than the tufa that formed in the cooler spring waters deposition of the travertine which formed largely on slopes in depressions and along fissure ridges mostly on northern basin margins was controlled by the interplay between various intrinsic and extrinsic parameters the travertines are formed largely of calcite with only minor amounts of aragonite in some of the vertically banded crystalline crust raft and pisoid travertines found in some of the northern sites the aragonitic samples rich in sr are typically found around the spring orifices and along the central axis of the fissure ridges the stable isotope values of the travertine found in the northwest and southeast parts of the basin are different the 13c values of the northern travertine deposits are more positive 3 7 to 11 7 vpbd than those found in the south southeast areas 4 to 5 8 vpdb in contrast the travertine and tufa in the southeastern areas have higher 18o values 15 2 to 7 8 vpdb than those of the northern areas 16 6 to 4 8 vpdb available evidence indicates that spring activity and associated travertine precipitation in the denizli basin were controlled largely by tectonic activity rather than by climatic conditions

long term seismicity of istanbul and of the marmara sea region we examine the long term seismicity of the marmara sea region in turkey over a period of twenty centuries to attempt to answer two questions 1 how well recorded in history is the earthquake activity of this region and 2 does seismicity over this long period of time differ from that over the present century we study this densely populated and fast developing region because it is one of the most tectonically active regions on the continents that appears today to be relatively quiescent

topex poseidon derived space time variations of the kuroshio current applications of a gravimetric geoid and wavelet analysis summary using topex poseidon t p altimeter data and a gravimetric geoid we derived 7 year time series of kuroshio s volume transport axis velocity width and axis locations northeast and southeast of taiwan for northeastern and southeastern taiwan the mean volume transports are 19 and 26 sv the mean widths are 112 and 96 km and the mean axis velocities are 50 and 82 cm s 1 respectively the t p derived volume transports agree well with in situ result drifter d21160 almost passes through the t p derived axes of the kuroshio the time series show intraseasonal semi annual annual and interannual variations but the frequency characteristics at the two locations are different owing to monsoon bottom topography and other factors wavelet analyses show that the amplitudes and phases of the frequency components vary with time a biennial component is found in almost all time series and may be excited by the tropical quasi biennial oscillation of the atmosphere the volume transport northeast of taiwan has a positive correlation 0 6 with enso with a 1 month lag and both the volume transport and velocity southeast of taiwan have a negative correlation 0 6 with enso with a 9 10 months lead

morphotectonic evidence from the southern branch of the north anatolian fault naf and basins of the south marmara sub region nw turkey this study investigated the morphotectonic evidence from the southern branch of the north anatolian fault naf and the south marmara sub region nw turkey the south marmara sub region has two uplifts located in the south and north and a depression between these uplifts the uplifts are bounded by the southern branch of the naf the southern branch is divided into the yenice gonen ygfz manyas mustafakemalpasa mmf uluabat ufz and bursa bfz faults the relation between the active tectonics and recent morphology were evaluated by using the geomorphic indices gis af asymmetry factor t topographic symmetry factor sl river length gradient index smf mountain front sinuosity gis were used to define the effects of tectonism on morphology and were used to calculate the relative tectonic activity index iat the values obtained through the gis indicate a young tectonism in the study area the study area morphometrically presented two iat classes class 1 high relative tectonic activity and class 2 moderate relative tectonic activity the present gps data and iat classes of the southern branch faults of the nafz were correlated all of the calculations and field data reveal that the southern branch of the naf is the main tectonic element forming the geomorphology of the south marmara sub region

regulation of south china sea throughflow by pressure difference sea surface height ssh data from the european centre for medium range weather forecasts ocean reanalysis system 4 ecmwf oras4 are used to determine the pressure difference in connection with variability of the south china sea throughflow scstf from 1958 to 2007 two branches of scstf the karimata sunda strait throughflow ksstf and the mindoro strait throughflow mstf are examined using the ensemble empirical mode decomposition method eemd time series of pressure difference and volume transport are decomposed into intrinsic mode functions and trend functions with the corresponding variability on different time scales pressure difference agrees with the ksstf volume transport on decadal time scale while for the mstf pressure difference varies similarly with volume transport on interannual time scale separating the dynamic height difference into the thermal and haline terms for the ksstf more than half of the dynamic height difference 32 cm is due to the thermal contributions while the remaining dynamic height difference 23 cm is due to the haline contributions for the mstf the dynamic height difference 29 cm is primarily due to the thermal contribution 26 cm

age determination for segments of the north anatolian fault naf northern branch by 234u 230th dating of sogucak yalova range front travertines south marmara turkey abstract the sogucak travertine occurrences developed along north segment of the north anatolian fault naf in yalova province marmara region turkey the range front type travertines outcropping over an approximately 1 km2 area with 20 40 m thickness are middle thick bedded and back tilted southward or horizontally lithology of the travertines includes physolite stalactites stalagmites cave pearls sharp pebble carbonate nodules spherical roller intricate shapes and laminated banded travertines geochemical analysis was performed on six samples of the travertines the samples showed high calcite composition averagely 98 and mg carbonite content varying from 0 87 to 1 33 the travertines were deposited by means of normal faults as indicated by structural and morphological relationship with active tectonics 234u 230th dating of the travertines provided an age range from 61 318 3 091 to 231 944 141 902 ka findings show that the travertine deposition and deployment of faults in the region occurred approximately at 231 ka corresponding to middle pleistocene therefore the age of both travertines and naf was determined as middle pleistocene

modulation of rossby waves on the pacific north equatorial current bifurcation associated with the 1976 climate regime shift simulated current velocity and long term reanalysis wind data are used to investigate interannual variations in the bifurcation of the pacific north equatorial current nec after the 1976 climate regime shift wind stress curl anomaly wsca in the region of 10 n 15 n and 160 e 170 e generates rossby waves and affects the nec bifurcation along the philippine coast from 1976 to 1992 following a regime shift to the positive pacific decadal oscillation pdo phase pdo and el nino southern oscillation enso match each other in strength and have a neutralized effect on the wsca from 1993 to 2009 wsca matches pdo well and its correlation with enso is lower using a linear regression model we show that the influence of pdo has nearly 13 times weight over that of enso prior to the 1976 regime shift wsca is closely related to enso from 1961 to 1975 and it does not correlate significantly with pdo our analysis results show that rossby waves are preferentially generated in either the negative pdo phase when the enso signal dominates or in the positive pdo phase when the enso signal is overshadowed in the phase when the positive pdo counteracts with the enso signal neither enso nor pdo has a significant influence on rossby wave generations through the wsca

influence of an island on hysteresis of a western boundary current flowing across a gap abstractwe investigate impact of an island on hysteresis of a western boundary current wbc flowing across a gap using a nonlinear 1 5 layer ocean model the results of hysteresis curves show the

morphologic features of the marmara sea from multi beam data abstract the bathymetrical image of the marmara sea nw of turkey was prepared using data from mainly multi beam surveys and from various other sources the marmara sea presents a unique and complicated morphological system which is mainly controlled by the active tectonic regime of the north anatolian fault zone nafz the sub bottom morphology of the marmara sea consists of a wide shelf area 55 of the total area and the marmara trough which includes the slopes ridges and deep basins the four basins separated by ridges constitute the e w trending marmara trough in an elliptical form submarine canyons and landslides constitute the secondary morphological units of the marmara sea the angle and the shape of the slopes are variable in different parts of the marmara sea the linear shaped slopes bounding the cinarcik basin eastern extremity of the marmara sea and off the ganos mountain system west of marmara sea are characteristic with their high gradient and resulted from strike slip fault the curve shaped slopes with low angles are considered to be associated with normal fault e w aligned lineaments are morphological expressions of strike slip faults and can be traced from the ganos mountain system through cinarcik basin cutting through the basins and ridges in the western marmara trough and bounding the cinarcik basin at the slope basin transitions these lineaments reflect a new rupture of nafz and must have occurred after the formation of the marmara trough

interannual to decadal variability and trends of sea level in the south china sea interannual to decadal variability and trends of sea level in the south china sea scs are studied using altimetric data during 1993 2012 and reconstructed sea level data from 1950 2009 the interannual variability shows a strong seasonality surface wind anomalies associated with el nino southern oscillation explain the sea level anomaly pattern in the interior scs while rossby waves radiated from the eastern boundary dominate the sea level variability in the eastern scs decadal variability of sea level in the scs follows that in the western tropical pacific with large variance found west of luzon island local atmospheric forcing makes a negative contribution to decadal variability in the central scs and rossby waves radiated from the eastern boundary appear to be important during 1993 2012 decadal sea level averaged in the scs is significantly correlated with the pacific decadal oscillation pdo r 0 96 the decadal variability associated with the pdo accounts for most part of sea level trends in the scs in the last two decades

the active main marmara fault abstract this paper presents selections from and a synthesis of a high resolution bathymetric sparker and deep towed seismic reflection data set recently acquired by the french ifremer r v le suroit in an e w deep trough that forms the northern half of the sea of marmara in nw turkey it includes the first high resolution complete bathymetric map of this area a single throughgoing dextral strike slip fault system which is the western continuation of the northern branch of the north anatolian fault cuts this trough lengthwise and joins the 1999 8 17 kocaeli earthquake fault with the 1912 8 09 arkoy murefte earthquake fault both of which display strike slip offset in its eastern one fourth the structure follows closely the northern margin of the deep trough whereas in the west it hugs its southern margin the eastern one fourth of the structure has a minor component of its displacement distributed across the deep trough owing to a possible original bend in the course of the dextral structure the present course of the north anatolian fault in the sea of marmara originated some 2 105 a ago by cutting across the older basin fabric generated by a dominant nne ssw extension before it began taking up major motion in the pliocene

topex poseidon observations of mesoscale eddies over the subtropical countercurrent kinematic characteristics of an anticyclonic eddy and a cyclonic eddy 1 relative dynamic heights and geostrophic fields were derived from topex poseidon altimetry data and then used to track mesoscale eddies over the subtropical countercurrent stcc the radii centers vorticities shearing deformation rates stretching deformation rates divergences and center velocities of all identified eddies over the stcc were determined using a model that assumes constant velocity gradients most eddies are concentrated in a zonal band near 22 n and there is an interannual variation in the number of eddies a case study was made for a cyclonic eddy and an anticyclonic eddy with time series of eddy kinematic parameters computed both eddies survive for 220 days and propagate westward along over 22 n 24 n to reach the kuroshio current east coast of taiwan where the eddies were dissipated and in turn affected the kuroshio current in many ways sea surface temperature data and drifter data confirm the existence of these two eddies the radii of both eddies vary and their shapes are mostly elliptical during propagation the anticyclonic eddy propagated almost westward with oscillating north south components and the mean speed is 8 3 km day the cyclonic eddy moved southwestward before reaching 130 e and then moved northwestward with a mean speed of 7 6 km day the propagations of these two eddies are basically consistent with the standard theory of eddy propagation but with larger speeds the propagating direction could be altered while passing steep bottom topography or merging with the other eddies index terms 4520 oceanography physical eddies and mesoscale processes 4576 oceanography physical western boundary currents 4512 oceanography physical currents 4594 oceanography physical instruments and techniques 4556 oceanography physical sea level variations

interannual variability of the south china sea in a data assimilation model 1 sea surface height ssh variations in the south china sea are examined using results from a data assimilation model after the ssh data have had the annual cycle removed principal component analysis illustrates two distinct anomaly patterns the first mode strongest off vietnam would affect the basin wide gyre intensity the second mode consists of a meridional dipole feature with a nodal line around 12 n and is related to the development of the eastward jet and upwelling off vietnam both eof modes have significant interannual variations and are highly correlated to the enso events the leading phase of mode 2 coefficient provides preliminary evidence for the air sea interaction and the pacific east asian teleconnection an innovative mechanism is proposed to describe a weakened upwelling off luzon in winter 1998 an extra strong basin wide warming in summer 1998 persists into fall and winter preventing the formation of winter upwelling off luzon in that year

coral record of variability in the upstream kuroshio current during 1953 2004 the kuroshio current kc one of the most important western boundary currents in the north pacific ocean strongly affects regional hydroclimate in east asia and upper ocean thermal structure limited by few on site observations the responses of the kc to regional and remote climate forcings are still poorly understood here we use monthly coral 18o data to reconstruct a kc transport record with annual to interannual resolution for the interval 1953 2004 the field site is located in southern taiwan on the western flank of the upstream kc increased reduced kc transport would generate strong weak upwelling resulting in relatively high low local coral 18o the upstream kc transport and downstream transport off tatsukushi bay japan covary on interannual and decadal timescales this suggests common forcings such as meridional drift of the north equatorial current bifurcation or zonal climatic oscillations in the pacific the intensities of kc transport off southeastern and northeastern taiwan are in phase before 1990 and anti phase after 1990 this difference may be due to a poleward shift of the subtropical western boundary current as a response to global warming

interannual variability in the mid and low latitude western north pacific abstract twenty two years 1967 88 of hydrographic data collected by the japan meteorological agency along the 137 e meridian and surface wind data compiled by florida state university fsu were analyzed to study the interannual variability in the western north pacific in the midlatitude region north of 22 n the dominant signal in the dynamic height field was the interannual path variations of the kuroshio whereas the eastward transport of the kuroshio itself had no significant changes between the straight path and meander path years the net transport of the kuroshio system including recirculations showed a 30 increase during the meander path years in the straight path years when the net transport was small the kuroshio tended to take a straight path with a strong recirculation developed to the south the interannual path variations of the kuroshio strongly influenced the water mass movement in the midlatitudes during the kuroshio meander years we found that a significant portion of the north p

blocking and westward passage of eddies in the luzon strait satellite observations have shown the abundance of generally westward propagating eddies in the subtropical regions in the north pacific ocean especially north of 10 n eddies transport mass and can significantly impact the circulation as well as the heat salt and nutrient balances of the western pacific marginal seas this paper uses a numerical model to examine the conditions when eddies can or cannot freely propagate westward through the luzon strait into the south china sea scs composite analyses on the 10 year model data show that the fates of eddies depend on the strength and path of the kuroshio in one path that exists mostly during fall and winter the kuroshio loops westward into the scs the potential vorticity pv across the current is weak and eddies are likely to propagate freely through the luzon strait in another path which exists mostly during spring and summer the kuroshio tends to leap directly northward bypassing the scs the pv across it strengthens and eddies are then blocked and are constrained to also follow the northward path nonlinear eddy current interaction and the existence of a cyclone north of the luzon island during the looping phase explain why eddies of both signs can pass through the strait it is shown also that the upstream state of the kuroshio in the western tropical pacific plays an important role in dictating the different paths of the kuroshio the looping leaping path is caused by a weakened stronger kuroshio transport related to the northward southward shift of the north equatorial current in wintertime summertime

decadal oscillation of spring rain in northern taiwan 1 this study found that the spring february april rainfall in northern taiwan has fluctuated concurrently with the pacific decadal oscillation pdo since the early 20th century it is proposed that this fluctuation in spring rain is induced by the tropical sea surface temperature sst anomaly embedded in the pdo which has been known to oscillate in opposite phase to the sst in the extra tropical north pacific when the pdo index is positive negative the sst over the tropical central eastern pacific is warmer colder than normal and a low level anti cyclonic cyclonic anomalous flow is induced over the philippine sea this anomalous anti cyclonic cyclonic flow results in southwesterly northeasterly anomalous winds to the east of taiwan and enhances reduces the trough extending southwestward from southern japan to northern taiwan as a consequence more less spring rain occurs in northern taiwan during the positive negative pdo phases

upper layer circulation in the south china sea abstract upper layer circulation is investigated by using all available historical temperature profiles combined with climatological temperature salinity relationships in the south china sea two cyclonic eddies are revealed one is located east of vietnam called the east vietnam eddy and the other is off northwest luzon called the west luzon eddy both local ekman pumping and remotely forced basin scale circulation are important mechanisms controlling these two eddies the luzon strait transport relative to 400 db is estimated to be of the order 3 0 sv 1 sv 1 106 m3 s 1 in the mean and has a seasonal cycle dominated by the annual signal with a maximum 5 3 sv in january february and a minimum 0 2 sv in june july pressure gradients are also examined to explore the dynamics of the intrusion of waters from the pacific into the south china sea through the luzon strait

strengthening kuroshio observed at its origin during november 2010 to october 2012 direct measurements of kuroshio at its origin 18 degrees n east of the luzon island are conducted from november 2010 to october 2012 it is found that the depth averaged kuroshio between 200 and 700 m has increased over 15 cm s 1 during the 2 year observational period and it is accompanied by the pronounced southward shift of the north equatorial current nec bifurcation further analysis indicates that the kuroshio s strengthening is confined to the upstream segment east of the luzon island while the kuroshio decreased as it passed the luzon strait due to a dipole like sea surface height ssh trend between 15 degrees n and 23 degrees n it is demonstrated that the 2 year strengthening of the kuroshio as well as the dipole like ssh trend can be adequately reproduced by a 1 5 layer nonlinear reduced gravity model suggesting an important role of upper ocean response to low frequency wind forcing in the western pacific salinity at 500 m depth is also found to increase during the concurrent 2 years this subthermocline salinity increase is a combined outcome of vertical basin scale isopycnal surface movement and horizontal advections i e strengthened kuroshio due to changes in the large scale wind driven ocean circulation

a new technique for precise uranium series dating of travertine micro samples abstract secondary carbonate formations such as travertine and calcareous tufa deposits are important archives for quaternary continental climate studies and archaeology the extremely complex growth mechanisms result in some serious problems for precise mass spectrometric uranium series dating often detrital and organic particles contaminate the carbonate and large pore volumes yield a great potential for open system behavior we utilized microscopic mineralogical and geochemical methods prior to sample selection to determine the abundance of primary calcite i e micrite and spar furthermore the state of alteration was characterized by cathodoluminescence and trace element analysis we conclude that travertine and calcareous tufa are appropriate for precise u series age determination if a micrite and or spar are the dominant phases b cathodoluminescence of both phases is weak or absent c fe and al levels are low and d sr concentrations are close to the average of the studied site we mapped and sampled solely areas of major micrite spar abundance having minor alteration for accurate u series dating when this new method was applied travertines located in eastern germany sites bad langensalza burgtonna and weimar ehringsdorf gave single 230th 238u ages consistent with the lithological growth sequence and greatly improved compared to previously published chronologies in addition we determined 230th u isochron ages on bulk samples that confirm our single ages in contrast to primary calcite pore cements are homogeneously distributed throughout the travertine fabric and reflect early diagenetic processes and or weathering

observations of inflow of philippine sea surface water into the south china sea through the luzon strait abstract velocity observations near the surface made with argos satellite tracked drifters between 1989 and 2002 provide evidence of seasonal currents entering the south china sea from the philippine sea through the luzon strait the drifters cross the strait and reach the interior of the south china sea only between october and january with ensemble mean speeds of 0 7 0 4 m s 1 and daily mean westward speeds that can exceed 1 65 m s 1 the majority of the drifters that continued to reside in the south china sea made the entry within a westward current system located at 20 n that crossed the prevailing northward kuroshio path in other seasons the drifters looped across the strait within the kuroshio and exited along the south coast of taiwan during one intrusion event satellite altimeters indicated that directly west of the strait anticyclonic and cyclonic eddies resided respectively north and south of the entering drifter track the surface currents measured by the crossing drifters were much

the north anatolian fault a new look dedicated to the memory of three pioneers ihsan ketin sirri erinc and melih tokay and a recent student aykut barka who burnt himself out in pursuit of the mysteries of the north anatolian fault abstract the north anatolian fault naf is a 1200 km long dextral strike slip fault zone that formed by progressive strain localization in a generally westerly widening right lateral keirogen in northern turkey mostly along an interface juxtaposing subduction accretion material to its south and older and stiffer continental basements to its north the naf formed approximately 13 to 11 ma ago in the east and propagated westward it reached the sea of marmara no earlier than 200 ka ago although shear related deformation in a broad zone there had already commenced in the late miocene the fault zone has a very distinct morphological expression and is seismically active since the seventeenth century it has shown cyclical seismic behavior with century long cycles beginning in the east and progressing westwa

the north anatolian fault within the sea of marmara a new interpretation based on multi channel seismic and multi beam bathymetry data abstract we analyze 2200 km of multi channel seismic reflection profiles that have become recently available in the sea of marmara this analysis benefits from the recent acquisition of multi beam bathymetric data covering the axial portion of the northern basins we conclude that the northern sea of marmara is at present cut by an active continuous strike slip fault system that we call the marmara fault it links the 270 izmit portion of the northern branch of the north anatolian fault to the east of the sea to the 245 ganos fault to the west the marmara fault itself consists of two main parts the western one is a single 80 km long fault it follows a 265 direction that differs by 20 from the direction of the ganos fault at its northeastern extremity it turns toward the northern margin of the cinarcik basin this western part of the fault is seismically quite active the eastern part is more complex it extends over 65 km in a 280 direction there is thus a 10 clockwise rotation with respect to the 270 izmit fault strand that should result in a slight extensional component within the eastern cinarcik basin this part of the marmara fault has two parallel branches 10 km apart the northern one near the foot of the northern slope the southern one near the foot of the southern slope a shortening zone occupies the northwestern corner of the cinarcik basin and much of the adjacent eastern central high and separates the northern branch from the western one the southern branch on the other hand may cross the eastern central high along a narrow 280 valley the data we have provide no definitive evidence on which of these two branches carries most of the motion the establishment of the present trace of the fault through the marmara basin is contemporaneous with a recent phase of deposition of deep giant ripples parallel to the bathymetric slope contours and adjacent to the turbidites basin deposits the base of these deep basins sedimentary deposits is marked by a widespread erosional unconformity below which lies a gently folded sedimentary sequence that may consist of shallow thrace basin deposits

mesoscale eddies in the northern south china sea a fine grid resolution model with realistic bathymetry and forcing has been developed to study the characteristics of the mesoscale eddies for the northern south china sea scs the scs model derives its open boundary conditions from a larger scale model which minimizes errors related to the uncertainty of the kuroshio intrusion at the open boundaries the model results are consistent with previous observations model sea surface height anomaly demonstrates that the hydrography and circulation in the northern scs are modulated by westward propagating mesoscale eddies originating in the vicinity of the luzon strait this explains the observed intra seasonal fluctuations at the southeast asian time series study seats station the mesoscale eddies have the same propagation speed as baroclinic rossby waves 0 1 ms 1 the periods of eddy shedding estimated from strouhal number are around 40 50 days in december and 80 120 days in august respectively the seasonal variability of the kuroshio intrusion results in more eddies in winter than in summer r 2007 elsevier ltd all rights reserved

growth of fissure ridge travertines from geothermal springs of denizli basin western turkey fissure ridge travertines grown from geothermal springs of denizli basin southwestern turkey are investigated through stratigraphic structural geochemical and geochronological methods with the aim of understanding the growth of these elongate mound shaped structures two main types of travertine deposits are recognized 1 bedded travertines which grew as flowstone on sloping surfaces and form the bulk of fissure ridges and 2 banded travertines which grew as veins within the bedded travertine chiefly along its central feeding conduit stratigraphic and structural observations shed light on the bedded banded travertine relationships where the banded features grew through successive accretion phases crosscutting the bedded travertine or forming sill like structures the bedded and banded travertines alternated their growth as demonstrated by complicated crosscutting relationships and by the upward suture in places of banded travertine by bedded travertine that was in turn crosscut by younger banded travertine the bedded travertine is often tilted away from the central axis of the fissure ridge thus leaving more room for the central banded travertine to form u series ages confirm the bedded banded travertine temporal relationships and show that the growth of the studied fissure ridges lasted up to several tens of thousands of years during quaternary time the banded travertine was deposited mainly during cold events possibly in coincidence with seismic events that might have triggered the outflow of deep geothermal fluids c and o stable isotope and rare earth element data indicate a shallow feeding circuit for the studied structures with a fluid component deriving from a deeper geothermal circuit a crack and seal mechanism of fissure ridge growth is proposed modulated by the interplay of local and regional influencing factors and mechanisms such as geothermal fluid discharge paleoclimate tectonics and the progressive tilting of bedded travertine limbs over a soft substratum creating the necessary space for the central veins to grow

pacific east asian teleconnection how does enso affect east asian climate observational evidence is presented to show a teleconnection between the central pacific and east asia during the extreme phases of enso cycles this pacific east asian teleconnection is confined to the lower troposphere the key system that bridges the warm cold events in the eastern pacific and the weak strong east asian winter monsoons is an anomalous lower tropospheric anticyclone cyclone located in the western north pacific the western north pacific wind anomalies develop rapidly in late fall of the year when a strong warm or cold event matures the anomalies persist until the following spring or early summer causing anomalously wet dry conditions along the east asian polar front stretching from southern china northeastward to the east of japan kuroshio extension using atmospheric general circulation and intermediate models the authors show that the anomalous philippine sea anticyclone results from a rossby wave response to suppressed convective heating which is induced by both the in situ ocean surface cooling and the subsidence forced remotely by the central pacific warming the development of the anticyclone is nearly concurrent with the enhancement of the local sea surface cooling both the anticyclone and the cooling region propagate slowly eastward the development and persistence of the teleconnection is primarily attributed to a positive thermodynamic feedback between the anticyclone and the sea surface cooling in the presence of mean northeasterly trades the rapid establishment of the philippine sea wind and sst anomalies implies the occurrence of extratropical tropical interactions through cold surge induced exchanges of surface buoyancy flux the central pacific warming plays an essential role in the development of the western pacific cooling and the wind anomalies by setting up a favorable environment for the anticyclone sst interaction and midlatitude tropical interaction in the western north pacific

seasonal and interannual changes of the kuroshio intrusion onto the east china sea shelf an advanced artificial neural network classification algorithm is applied to 20 years of multisatellite geostrophic velocity data to study the kuroshio intrusion onto the southern shelf of the east china sea the results suggest that the on shelf intrusion may occur year round but winter intrusion events are more frequent than summer events both stronger intrusion which is closely correlated to surface heat flux gradient and weaker intrusion which is correlated to wind forcing occur during wintertime but the former dominates in late winter while the latter prevails in early winter there is a significant year to year variation of the winter on shelf intrusion although on shelf intrusion is the major characteristic of the region during wintertime seldom intrusion events have been identified in the winters of 1997 1998 and 2002 2003 two conditions are responsible for the cause of the nonintrusion events during the two nonintrusion winters the upstream kuroshio transport anomaly is insignificant the kuroshio is not weakened and no significant winter cooling off northeast taiwan thus the kuroshio tends to flow along the shelf break following the 200 m isobath and on shelf intrusion ceases those two nonintrusion events take place during the winters when both the nino 3 4 index and the pdo index are large and positive

fluctuations of the thermal fronts off northeastern taiwan 1 a high resolution sea surface temperature sst data derived from several satellites is used to investigate the variability of the thermal front off northeastern taiwan hidden by a dominant annual cycle the sst data cannot reveal the thermal front fluctuation in the form of hovmoller diagram an innovative methodology has been applied to the sst satellite imagery to derive the sst standardized index sstsi capable of revealing the frontal variability with multiple time scales principal component analysis shows that the sstsi variation consists mainly of two modes mode 1 represents a strong annual cycle related to the seasonal reversal of the monsoonal winds the temperature gradient is enhanced in winter and a cold dome is observed off northern taiwan in summer mode 2 is highly correlated with the upstream kuroshio variability the shoreward seaward migration of the thermal front takes place when the kuroshio transport weakens strengthens the results are consistent with transports estimated by tidal gauge measurements satellite altimeter based sea level anomaly and surface flow patterns derived from high frequency radars mode 2 is coherent with the kuroshio transport through the east taiwan channel at periods of 120 and 45 d with a time lag of 40 and 11 d respectively this 120 d fluctuation is due to the interaction between westward propagating eddies and the kuroshio east of taiwan while the 45 d signal arises from the kuroshio s self instability the interannual variations of the sst pattern in winter and summer are also discussed

multidecadal variations of the surface kuroshio between 1950s and 2000s and its impacts on surrounding waters based on the analyses of 59 year 1950 2008 surface geostrophic velocities the multidecadal changes of kuroshio from the eastern luzon to the southern japan are investigated result shows that the upstream kuroshio from the east of luzon to southern east china sea suffers much more obvious multidecadal changes except for the decade of 1980 the kuroshio east of luzon possesses a multidecadal tendency opposite to that east of taiwan besides 1980s the multidecadal change of kuroshio bordering taiwan is mainly governed by the eddy activity off the eastern taiwan while the wind stress curl plays a major role in the kuroshio in the east of luzon and in the luzon strait the wind stress induced ekman transport plays a secondary role in regulating the kuroshio east of luzon in addition the multidecadal fluctuation of kuroshio east of luzon also modulates the westward intrusion in the luzon strait instead the ekman transport dominated the whole upstream kuroshio area from the eastern luzon to the vicinity of taiwan during the exceptional decade of 1980 associated changes of water properties in the northern south china sea and southern east china sea are also ascribed to the multidecadal changes of surface kuroshio in the upstream area

spatial structure and temporal variability of the zonal flow in the luzon strait one year long full depth velocity measurements were used to examine the spatial structure and temporal variability of the zonal flow in the luzon strait lszf the observation revealed a renewed mean flow structure in the upper 2000 m layers the lszf was mostly westward in the intermediate layer 500 2000 m it was dominated by an eastward flow in the south but a westward flow in the north the volume transport across the observed section between 19 8 n and 21 2 n exhibited strong seasonal and intraseasonal variability on the seasonal time scale the upper layer transport showed a clear annual cycle strongest in january and weakest in june the intermediate layer transport also showed a semiannual cycle attaining its peaks troughs in january and june april and october on the intraseasonal time scale both the upper layer and intermediate layer transports showed significant energy peaks at about 60 and 10 30 days further analysis indicated that the 60 day variability might be attributed to the impinging mesoscale eddies from the pacific while the 10 30 day variability appeared to obtain its energy from local intraseasonal wind forcing and baroclinic instability of the background current the 10 100 day upper layer and intermediate layer transport variabilities were highly anticorrelated suggesting a baroclinic nature of the intraseasonal variabilities of the lszf

asymmetric slip partitioning in the sea of marmara pull apart a clue to propagation processes of the north anatolian fault between 1939 and 1999 the north anatolian fault naf experienced a westward progression of eight large earthquakes over 800 km of its morphological trace the 2000 km long north anatolian transform fault has also grown by westward propagation through continental lithosphere over a much longer timescale 10 myr the sea of marmara is a large pull apart that appears to have been a geometrical mechanical obstacle encountered by the naf during its propagation the present paper focuses on new high resolution data on the submarine fault system that forms a smaller pull apart beneath the northern sea of marmara between two well known strike slip faults on land izmit and ganos faults the outstandingly clear submarine morphology reveals a segmented fault system including pull apart features at a range of scales which indicate a dominant transtensional tectonic regime there is no evidence for a single continuous purely strike slip fault this result is critical to understanding of the seismic behaviour of this region of the naf close to istanbul additionally morphological and geological evidence is found for a stable kinematics consistent both with the long term displacement field determined for the past 5 myr and with present day anatolia eurasia motion determined with gps however within the sea of marmara region the fault kinematics involves asymmetric slip partitioning that appears to have extended throughout the evolution of the pull apart the loading associated with the westward propagation process of the naf may have provided a favourable initial geometry for such a slip separation

uranium series dating of travertine from suttő implications for reconstruction of environmental change in hungary abstract terrestrial carbonate formations such as travertines speleothems and lake sediments are important archives of terrestrial climate forcing at the sutt section in hungary a complex succession of travertine is covered by a loess palaeosol sequence both are high resolution terrestrial archives of climate and environment change uranium series 230th u dating was carried out to set up a more reliable chronological frame for the travertine as the growth of travertine is very complex pore cements may cause serious problems for precise dating the state of alteration of primary spar and micrite was characterised by microscopic cathodoluminescence and microprobe analyses the travertine from sutt showed homogeneous phases of primary calcite minor micropores and rare pore cements the carbon isotopic composition indicates that the source of carbon was a mixture of atmospheric and soil derived co2 calculated water temperatures based on oxygen isotope data range from 22 c to 31 c an attempt to provide an independent relative dating approach by palaeomagnetic techniques failed 230th u ages were determined applying an isochron approach using the leachate leachate method as the travertine deposits have a dense structure the bulk sampling method was successfully applied in determining uranium series ages with much higher precision than former studies with alpha spectrometry travertines from sutt yielded mid pleistocene ages ranging from the antepenultimate glacial to the penultimate interglacial 310 240 ka these results are in agreement with those from optically stimulated luminescence osl dating and amino acid racemisation aar dating of the overlying sediment indicating at least an mis 7 age for the travertine

evolution of a fault controlled fissure ridge type travertine deposit in the western anatolia extensional province the cukurbag fissure ridge pamukkale turkey in recent decades various interpretations have been proposed to explain the evolution of fissure ridge type travertine deposits in this paper we discuss the relationships between fissure ridges and brittle structures affecting their substratum through a detailed analysis of an inactive fissure ridge near cukurbag located in the pamukkale geothermal area western turkey the cukurbag fissure ridge can be taken as a model as it offers an opportunity to examine its internal structure on the walls of a roman quarry in addition this ridge has been studied by several researchers who have discussed the processes promoting the fissure ridge evolution the cukurbag fissure ridge is composed of irregularly alternating travertine laminated facies bedded travertine crosscut into rather large lithons by subvertical crystalline veins banded travertine the relationships between bedded and banded travertine indicate that the banded veins are diachronous and migrated through time suggesting a progressive fault zone enlargement in the footwall such a fault zone was characterized by polycyclic activity with normal to transtensional kinematics and was active during the latest quaternary we demonstrate that formation of banded veins is coeval with bedded travertine deposition and strictly depends on fault activity therefore highlighting the fundamental role of travertine fissure ridges in reconstructing palaeotectonic activity in a region

the uranium trend dating method principles and application for southern california marine terrace deposits abstract uranium trend dating is an open system method for age estimation of quaternary sediments using disequilibrium in the 238 u 234 u 230 th decay series the technique has been applied to alluvium colluvium loess till and marine sediments in this study we tested the u trend dating method on calcareous marine terrace deposits from the palos verdes hills and san nicolas island california independent age estimates indicate that terraces in these areas range from 80 ka to greater than 1 0 ma two low terraces on san nicolas island yielded u trend plots that have a clustered array of points and the ages of these deposits are indeterminate or highly suspect middle pleistocene terraces and one early pleistocene terrace on san nicolas island and all terraces on the palos verdes hills gave reasonably linear u trend plots and estimated ages that are stratigraphically consistent and in agreement with independent age estimates we conclude that many marine terrace deposits are suitable for u trend dating but u trend plots must be carefully evaluated and u trend ages should be consistent with independent geologic control

the seasonal variation of the intrusion of the philippine sea water into the south china sea the seasonal variation of the intrusion of the philippine sea water into the south china sea was studied by analyzing the historical hydrographic station data in the northern south china sea and the philippine sea water masses at 150 200 and 250 m were classified by discriminant analysis according to their temperature salinity characteristics at each depth most water in the study region was classified into two groups representing the philippine sea water and the south china sea water respectively the geographic distribution of water masses in the south china sea shows that the philippine sea water was present along the continental margin south of china between october and january a westward current in the northern south china sea in winter was inferred from the distribution of the intrusion water

regime shift of the south china sea sst in the late 1990s decadal variability of the south china sea scs sea surface temperature sst during 1982 2014 is investigated using observations and ocean reanalysis datasets the scs sst shows an abrupt transition from a cold to warm regime in the late 1990s based on the long term sst variability two epochs are defined 1982 1996 and 2000 2014 as cold and warm regimes respectively spanning on either side of the 1997 1999 scs warming despite the occurrence of strong el nino induced warming events the sst anomalies tend to be negative in the cold regime conversely during the warm regime the positive sst anomalies have dominated over the la nina driven cooling events the cold warm sst regime is marked by net heat gain loss by the scs the long term variations of net surface heat flux are mainly driven by the latent heat flux anomalies while the short wave flux plays a secondary role low frequency variability of the south china sea throughflow scstf appears to be closely related to the scs sst regime shift the scstf shows reversing trends during the cold and warm epochs the weakened scstf in the warm regime has promoted the scs warming by limiting the outward flow of warm water from the scs meanwhile enhanced scstf during the cold regime acts as a cooling mechanism and lead to persistent negative sst anomalies the change in trend of the scstf and sst regime shift coincides with the switching of pacific decadal oscillation from a warm to cold phase in the late 1990s

the impact of hydrological changes on travertine deposits related to thermal springs in the pamukkale area sw turkey pamukkale thermal waters 35 c exhibiting calcium bicarbonate sulfate composition and high carbon dioxide concentration are of a predominantly meteoric origin the meteoric fluid circulating through faults and fractures is heated by magmatic intrusions at great depth and ascends from deep reservoirs to the surface mixing with relatively cold groundwater in the near surface zone promotes different saturation conditions with respect to calcium carbonate that later precipitates at depth and or the surface dissolution deposition processes of calcium carbonate both at surface and depth environments may help to reconstruct past climate direction in the field during wet climate conditions a high rate of calcium carbonate accumulation would be expected to occur at the surface because thermal fluid would be under saturated with respect to calcium carbonate at depth because of a relatively higher mixing ratio with cold groundwater during dry climate conditions the thermal fluid would be super saturated at depth because of the highly acidic environment hydrometeorological studies reveal that the annual precipitation at the pamukkale hydrothermal field tends to decrease with time this climatic change in the area was also detected from geological records while humid climate conditions prevailed during the late quaternary the area has recently been affected by arid semi arid climate conditions followed by some episodic transitions this study has shown how the system has possibly reacted to different climate conditions since antiquity

seasonal to interannual variations in the intensity and central position of the surface kuroshio east of taiwan 1 seasonal and interannual changes of surface kuroshio intensity and central position east of taiwan during 1993 2012 are investigated by quantitatively analyzing the satellite altimetry product the kuroshio moves inshore offshore off northeast of taiwan in winter summer whereas it has an offshore inshore path off southeast of taiwan in winter summer the seasonal change of heat flux over the east china sea shelf is found to cause the seasonality of the kuroshio central position off northeast of taiwan whereas the seasonal kuroshio movement off southeast of taiwan is found to be induced by the combined effect of the kuroshio changes through the luzon strait and the eastern luzon island in contrast to this y dependent path changes the kuroshio becomes weaker stronger as a whole east of taiwan in winter summer on the interannual time scales the kuroshio throughout the eastern coast of taiwan intensifies and has a concurrent offshore path during the periods of 1995 1997 and 2004 2007 the relative intensity of cyclonic eddies to anticyclonic eddies off eastern taiwan are found to contribute to these interannual kuroshio changes

the influence of pore distribution on the hydraulic conductivity of some swedish tills abstract the relationship between pore size distribution and hydraulic conductivity was studied on 42 undisturbed till samples the results show a random pattern in the relationship between the total porosity and the hydraulic conductivity a significant positive correlation was obtained between the hydraulic conductivity and the porosity in the interval 95 30 m whereas no such relationship could be established between the hydraulic conductivity and coarser pores this could be explained by the fissility structure in the till matrix which forms continuous micro fissures about 50 100 m in width whereas the coarser pores are more or less isolated

kuroshio intrusion into the south china sea a review the kuroshio carrying the northwestern pacific water intrudes into the south china sea scs through the luzon strait significantly affecting the temperature salinity circulation and eddy generation in the scs thus the kuroshio intrusion makes important contributions to the momentum heat and salt budgets in the scs in the past decades much work has been done on the kuroshio intrusion this paper reviews past efforts and summarizes our current understanding of the kuroshio intruding processes from observational evidence laboratory results theoretical analyses and a range of numerical model simulations in addition discrepancies between results simulated by models as well as those between simulations and observations are presented specifically this paper addresses the following topics 1 different types of the kuroshio intrusion into the scs and their identification 2 vertical structure of the kuroshio in the luzon strait 3 an overview of the luzon strait transport resulting from observations and numerical model simulations 4 seasonal and interannual variations of the kuroshio intrusion as well as eddy generation due to the kuroshio path variation and 5 dynamical mechanisms e g wind forcing interbasin pressure gradient beta effect and hysteresis potential vorticity eddy activity controlling the kuroshio intrusion into the scs finally several future research topics for gaining a better understanding of the kuroshio intruding processes are suggested c 2014 the authors published by elsevier ltd

neotectonics of the sw marmara region nw anatolia turkey this study reports on the geometric and structural characteristics of the north anatolian fault zone in the southwest marmara region the geometric and kinematic features of the faults in the region are described based on field observations in addition the neogene and quaternary basin fill which occupies large areas in the region has been determined and the tectonic regimes controlling these basins are explained the neotectonic regime is also explained considering different deformation phases affecting the region the n s extension and e w strike slip have affected the region possibly since the latest pliocene quaternary field observations show that these extensional tectonics around the south marmara region are related to right strike slip on the e w north anatolian fault zone and the n s aegean extensional system the faults in this zone trend approximately e w in the eastern part of the region and ne sw towards the west of the region indicating that they accommodate rotation in addition to differential movement between adjacent blocks

travertines depositional morphology and the bacterially constructed constituents abstract investigation of travertine accumulations throughout central italy and the west central u s has shown that the carbonate is precipitated in response to both inorganic and organic processes individual deposits range up to 85 m thick and hundreds of square kilometers in areal extent all of the carbonate is low magnesian calcite water chemistry temperature and morphology of the accumulation greatly influence the constituents comprising these deposits harsh environmental situations favor inorganic deposits while increasingly more moderate conditions result in the formation of a greater abundance of organically precipitated material morphological variations of travertine deposits recognized include 1 waterfall or cascade 2 lake fill 3 sloping mound fan or cone 4 terraced ound and 5 fissure ridge gross morphology internal stratification and constituents comprising these deposits vary systematically depending upon the type of accumulation and chemistry of the waters bacterially precipitated calcite forms a large percentage of the carbonate in many travertine accumulations exceeding 90 of the framework grains comprising some of the lake fill deposits bacteria are among the first taxa to inhabit and reproduce in harsh spring environments and produce a variety of fascinating constituents the bacteria are primarily rods generally 0 2 m in diameter and less than 1 0 m in length the rods readily decay resulting in calcite crystals loaded with micropores the basic building block of bacterially constructed travertine is a clump of bacteria averaging 20 m in diameter enclosed in a single crystal of calcite aggregates of these crystals produce a variety of deposits including 1 crudely laminated carbonate mud 2 finely laminat d layers of mud 3 intraclasts 4 foam rock and 5 shrubs the shrubs are most striking commonly forming layers 1 3 cm thick but also producing bacterial pisoids at some locales bacterial stromatolites composed of layers of shrubs alternating with finely laminated layers of bacterial mud comprise essentially the entire deposit the shrub layers are the result of flourishing summer growth of bacteria and furthermore show remarkable daily laminae 0 1 0 5 mm thick the importance of bacteria in the formation of travertine and their universally recognized abundance in modern sediments provides an impetus for a reexamination of the role of bacteria in the origin of other types of ancient deposits

u series analyses of the lower travertine at ehringsdorf ddr abstract u series analyses have been made of travertine samples from the archaeological site at ehringsdorf weimar the lower travertine in which hominid remains were found yields apparent ages from 350 000 to 200 000 yr correlation between isotope ratios yields an age of about 230 000 yr one sample of the upper travertine gives and age of 111 000 47 000 yr both upper and lower travertines contain fauna and flora indicative of interglacial conditions the lower travertine was deposited during isotope stage 7 while the upper travertine may have been formed during isotope stage 5 this contradicts most earlier biostratigraphic studies which assigned both lower and upper travertines to stages of the eem interglaciation correlative with isotope stage 5 the fauna and flora of the lower travertine are significantly different from those of the upper travertine however and in some respects are transitional to those of the travertines of bilzingsleben which appear to be older yet

interannual variability of the north pacific subtropical countercurrent and its associated mesoscale eddy field interannual changes in the mesoscale eddy field along the subtropical countercurrent stcc band of 188 258n in the western north pacific ocean are investigated with 16 yr of satellite altimeter data enhanced eddy activities were observed in 1996 98 and 2003 08 whereas the eddy activities were below average in 1993 95 and 1999 2002 analysis of repeat hydrographic data along 1378e reveals that the vertical shear between the surface eastward flowing stcc and the subsurface westward flowing north equatorial current nec was larger in the eddy rich years than in the eddy weak years by adopting a 2 layer reduced gravity model it is shown that the increased eddy kinetic energy level in 1996 98 and 2003 08 is because of enhanced baroclinic instability resulting from the larger vertical shear in the stcc nec s background flow the cause for the stcc nec s interannually varying vertical shear can be sought in the forcing by surface ekman

interannual to decadal variability in the bifurcation of the north equatorial current off the philippines satellite altimeter sea surface height ssh data from the past 17 yr are used to investigate the interannualto decadal changes in the bifurcation of the north equatorial current nec along the philippine coast the nec bifurcation latitude migrated quasi decadally between 108 and 158n with northerly bifurcations observed in late 1992 1997 98 and 2003 04 and southerly bifurcations in 1999 2000 and 2008 09 the observed necbifurcationlatitudecanbeapproximatedwellbythesshanomaliesinthe128 148nand1278 1308ebox east of the mean nec bifurcation point using a 1 layer reduced gravity model forced by the ecmwf reanalysis wind stress data the authors find that the ssh anomalies in this box can be simulated favorably to serve as a proxy for the observed nec bifurcation with the availability of the long term reanalysis wind stress data this helps to lengthen the nec bifurcation time series back to 1962 although quasi decadal variability was prominent in the last two decades the nec bifurcation was dominated by changes with a 3 5 yr period during the 1980s and had low variance prior to the 1970s these interdecadalmodulationsin the characteristics of the nec bifurcation reflect similar interdecadal modulations in the wind forcing field over the western tropical north pacific ocean although the nec bifurcation on interannual and longer time

the forcing mechanism leading to the kuroshio intrusion into the south china sea 1 we use a high resolution numerical model to examine the forcing mechanism responsible for kuroshio intrusion into the south china sea scs the collective wisdom is that variations in kuroshio intrusion are closely related to the wind inside or outside the scs a series of experiments was performed to identify the wind related forcing regulating the intrusion the experiments demonstrated that the importance of wind inside the scs is greater than that outside the scs furthermore the northwestward ekman drift due to northeasterly wind in winter intensifies the upstream kuroshio in the luzon strait enhancing the kuroshio intrusion into the scs in particular the wind stress curl wsc off southwest taiwan is chiefly responsible for the kuroshio intrusion both the wsc and intrusion show both seasonal and intraseasonal variation as the negative wsc off southwest taiwan becomes stronger it contributes to anticyclonic circulation the enhanced anticyclonic circulation helps the development of the kuroshio intrusion the consistency between wsc variability and the intrusion suggests that the wsc off southwest taiwan is essential to the kuroshio intrusion variability

interannual modulation of the pacific decadal oscillation pdo on the low latitude western north pacific to investigate the interannual variability in the northwestern pacific an empirical mode decomposition emd was applied to 17 year absolute dynamic topography adt data west of luzon island the philippines the mean sea surface height in this area is an appropriate index for the kuroshio intrusion into the south china sea scs significant interannual fluctuations were extracted by the emd the interannual variability was strongly correlated with the pacific decadal oscillation pdo index but not the el nino southern oscillation enso this indicated the potential impact of the pdo on the circulation in the area in the warm phase of the pdo positive index a southerly anomalous wind off the philippines causes a northward shift of the north equatorial current bifurcation latitude necbl this leads to a weakened kuroshio off luzon favoring kuroshio intrusion into the scs the northward migration of the necbl also results in a weakened kuroshio off southeast taiwan and a larger kuroshio transport off northeast taiwan the abundant westward propagating eddies impinging on the kuroshio in the subtropical countercurrent region increases this transport although the enso has little effect on monsoonal winds during the warm pdo phase it has a strong impact on the monsoon and meridional migration of the necbl during the cold phase of the pdo therefore necbl variations only show a close correspondence with the enso during the cold pdo phase because the influence of the enso is not stationary the impact of the pdo should be taken into account when examining interannual variability in the low latitude western north pacific

the tug of war between the west philippine sea and south china sea tropical waters and intermediate waters in the okinawa trough kuroshio subsurface waters are the major source of nutrients to the east china sea continental shelf a major fishing ground these subsurface waters are heavily affected by the south china sea scs tropical and intermediate waters which contain more nutrients than the tropical smax and intermediate smin waters from the west philippine sea wps a front was found to separate these waters from the scs and wps the reported front in the okinawa trough however was identified based only on one time data from a single cross section here historical hydrographic data between march 1950 and december 2011 are analyzed a vertical front tilted toward the west is found in all seasons in all years in the okinawa trough in winter the presence of the scs tropical water is the most prominent it is the weakest in autumn as for intermediate waters smin the wps and scs intermediate waters show much weaker seasonality compared with tropical waters although in summer the wps intermediate water contribution is slightly larger than during other times

middle pleistocene extinction process of pull apart basins along the north anatolian fault zone abstract numerous basins that present in northern turkey formed in plio quaternary period by the strike slip tectonics of the north anatolian fault zone these pull apart basins isolated from their surrounding topographies by major scarps of faults along their margins that mapped as active faults but the mapped recent traces in the pull apart basins are in disagreement about these marginal faults and commonly characterized by the faults that pass through basin floors in the cases of surface rupturings in great earthquakes during the last century these faults have migrated from the basin rims to the center of the basins in agreement with the extinction model of pull apart basins here we review observations about numerous basins along the north anatolian fault zone to show that the migration of these faults in middle pleistocene related with the maturity of basins through their evolution

development of the cambazli turgutlu manisa fissure ridge type travertine and relationship with active tectonics gediz graben turkey abstract travertine occurrences in the cambazli village area exist at the western edge of the gediz graben comprising the turgutlu neogene basin the cambazli travertine was classified into two main groups based on physical mineralogical and petrographic properties occurrences of travertine are probably due to faulting between the paleozoic units of menderes massif and the pliocene kanlitepe formation group i travertine is horizontal and oriented ne sw and nw se whereas group ii travertine occurrences are oriented e w direction the cambazli travertine is a fissure ridge type travertine continues to develop both in fissures and on the topographic surface as bedded deposits layered travertine is deposited on both surfaces of fissures it develops either symmetrically or asymmetrically with respect to the centre of the fissure kinematical analyses of listric normal fault measurements demonstrate that nne ssw extension occurred the cambazli travertine in the gediz graben has been deposited by hydrothermal waters rising through fracture systems probably related to an active listric normal fault developed in the north of the study area

the intrusion of water masses into the sea southwest of taiwan characteristics of water masses were analyzed to study the kuroshio intrusion into the sea southwest of taiwan hydrographic data were obtained from ctd conductivity temperature and depth casts during two cruises in may and august 1986 in may remnants of water intruding from the kuroshio were found on the continental slope south of the penghu channel by august these were replaced by water from the south china sea during this period water from the kuroshio also appeared near the southern tip of taiwan the intrusion current reached a depth of at least 500 m and was probably part of a cyclonic circulation in the northern south china sea the results support the hypothesis of a seasonal pattern of the intrusion process intrusion of water from the kuroshio begins in late summer intensifies in winter and ceases by late spring when south china sea waters again enter this region

strike slip deformation and u th dating of travertine deposition examples from north anatolian fault zone bolu and yenicag basins turkey the relation of the travertine deposition outcropping in the bolu and yenicaga basins located to the west of the north anatolian fault system nafs with the faulting of the zone nafz of the system in this part is examined these travertines are dated by u series travertine formations in the bolu and yenicaga basins are deposited in different ways and localities on pressure ridges in the releasing restraining bends of the strike slip faults and around the intersection of faults while the travertines of the uctepeler and belemur hill are deposited on the pressure ridges the travertines deposited in cigdem hill and cepni are deposited in the releasing restraining bends of the faults of the zone and the travertines in golkoy are deposited on the foot wall of the intersecting of the normal faults which encircles the west side of the basin as a result of the dating of the travertines on the study area by u series method the age data range between 52 649 8040 a and 96 308 17 674 a and between 17 962 1671 a and 133 463 76 882 a in the yenicaga and basins respectively information on fault activity is gained as a result of the dating of the travertines deposited due to the strike slip deformation on different segments of the nafz

an updated examination of the luzon strait transport 1 despite numerous previous estimates of luzon strait transport lst we attempt an update using a fine resolution model with these improvements the circulation in and around luzon strait shows up rather realistically intrusion of a kuroshio meander into the south china sea scs is seasonally varying the lst especially in the upper ocean caused by a small difference between the large meander inflow and outflow is also seasonally varying and subject to large standard deviation the annual mean lst is estimated to be westward 4 0 5 1 sv along 120 75 e we have also conducted process of elimination experiments to assess the relative importance of open ocean inflow outflow wind stress and surface heat flux in regulating lst and its seasonality the east asian monsoon winds stand out as the predominant forcing without it the upper ocean lst changes from westward to eastward ranging up to 4 sv and with misaligned seasonality triggering an inflow from the mindoro strait to the scs to replenish the water mass loss discounting monsoon winds sea level in the sulu sea is generally higher because it receives the indonesian throughflow before the scs which causes an inflow from the sulu sea to the scs on the other hand the annual mean wind from the northeast invites outflow from the scs to the sulu sea or inflow from the luzon strait weighing the two competing factors together we see the cessation of northeast monsoon as a condition favorable for the luzon strait outflow or the mindoro strait inflow