composition of modern sand and cretaceous sandstone derived from the sierra nevada california usa with implications for cenozoic and mesozoic uplift and dissection abstract the california sierra nevada represents the roots of a primarily cretaceous magmatic arc that is presently being dissected extensively in the south and to a lesser degree in the north where it is covered by cenozoic volcanic rocks the cenozoic magmatic arc built on top of the cretaceous arc has been dissected concurrently with northward migration of the mendocino triple junction south of which the magmatic arc is inactive a north to south transect from the modern cascade arc along the sierra nevada therefore acts as a proxy for evolution from an active undissected magmatic arc to a transitional arc to a dissected arc to intensely uplifted basement discriminant analysis of cascade and sierra nevada modern alluvial sand defines four compositional groups and clearly distinguishes volcaniclastic undissected arc and plutoniclastic uplifted basement end members two intermediate compositional groups are primarily volcaniplutoniclastic and metamorphiplutoniclastic the former group represents dickinson s 1985 transitional arc the latter represents dissected arc sand composition in the southern sierra nevada reflects significant uplift resulting from a combination of latest cretaceous paleogene uplift and late cenozoic basin and range extension footwall uplift of the western rift shoulder possibly enhanced by mantle lithosphere delamination high concentrations of quartz and feldspar and near absence of aphanitic lithic fragments are typical of the southern sierra nevada and are characteristic of dickinson s basement uplift cretaceous sandstone petrofacies of the great valley group gvg of western california document dissection of the cretaceous magmatic arc as well as erosion of residual orogenic highlands analogous to modern taiwan formed during latest jurassic arc continent collision nevadan orogeny when cretaceous petrofacies data are entered into the modern sand discriminant analysis as unknowns they are classified into the modern cascade sierra nevada groups and a group from taiwan the results confirm that the lowest gvg petrofacies represent erosion of the nevadan suture belt and the undissected post nevadan arc increasing dissection of the arc occurred during the cretaceous but most samples represent transitional arc indicating that even by the latest cretaceous laramide cessation of arc activity in california dissection of the magmatic arc was less than what we see today in the central and southern sierra nevada no cretaceous samples have compositions equivalent to the basement uplift of the southern sierra nevada the application of actualistic sand stone petrofacies in this study provides important constraints on models for the cretaceous to modern history of the sierra nevada as well as implications for arc evolution in general

equatorial inertia gravity waves observed in topex poseidon sea surface heights we report an evaluation of the ability of the topex poseidon altimeter to observe equatorial inertia gravity waves in the central pacific aliasing problems limit us to examining meridional mode two but this mode is an energetic one in the pacific basin these estimates of the temporal potential energy modulations are compared with estimates from tide gauges in the tropical pacific and we find that the time series obtained at these points show good agreement

chromium and nickel as indicators of source to sink sediment transfer in a holocene alluvial and coastal system po plain italy abstract a reliable quantitative estimate of changes in source to sink sediment transfer requires that high resolution stratigraphic studies be coupled with accurate reconstructions of spatial and temporal variability of the sediment routing system through time source to sink patterns from the contributing upland river catchments to the deltaic and coastal system are reconstructed from the holocene succession of the po plain on the basis of selected geochemical indicators sediment supplied to the delta area by the major trunk river the po exhibits naturally high cr and ni values which invariably exceed the maximum permissible concentrations for unpolluted sites this anomaly reflects remarkable sediment contribution from ultramafic ophiolitic parent rocks cropping out in the po drainage basin western alps and nw apennines in contrast alluvial and coastal plain deposits supplied by ophiolite free apenninic catchments invariably display lower cr and ni contents for constant sediment provenance domain cr and ni distribution is observed to be controlled primarily by hydraulic sorting clay silt deposits floodplain swamp and lagoon bay facies associations invariably show higher metal concentrations than their sandy counterparts fluvial channel distributary channel and beach ridge facies associations from a stratigraphic perspective in sedimentary basins characterized by strong differences in sediment composition geochemical fingerprinting of individual facies associations framed by surfaces of chronostratigraphic significance is proposed as an invaluable approach towards an accurate quantitative assessment of sediment storage in alluvial and coastal depositional systems as opposed to volumetric reconstructions based on lithologic or geometric criteria alone

contributions of wind forcing waves and surface heating to sea surface height observations in the pacific ocean the dominant processes affecting sea surface height ssh variability observed by the topex poseidon altimeter vary regionally in the pacific baroclinic rossby waves equatorially trapped kelvin waves steric response to seasonal heating and the response to wind stress curl forcing are all important the steric response to surface heating dominates seasonal ssh variability in the subpolar gyre and the eastern subtropical gyre south of the kuroshio extension and south of 20 n in the eastern pacific the dominant contribution to ssh is from near annual period rossby waves to quantify the wave energy observed ssh was assimilated into a kinematic model of westward propagating waves these waves account for 70 of ssh variance between 10 s and 10 n but only 30 between 10 n and 30 n although wave energy in the eastern pacific is correlated with ssh anomalies at the equator the much larger wave energy in the western pacific is correlated with wind stress curl suggesting that the rossby waves there are locally forced in addition to these planetary waves the ocean response to wind forcing via ekman pumping is observed in several places specifically in the north equatorial current a quasi steady topographic sverdrup balance is detectable over most of the north pacific at latitudes as low as 10 15 n as well as in the south pacific where it is seen north of 50 s the decomposition of the ssh signal into propagating waves an ekman pumping response and sverdrup transport is consistent with the results from an isopycnal numerical model

inferring tectonic provenance of siliciclastic rocks from their chemical compositions a dissent abstract chemical compositions of siliciclastic sedimentary rocks are commonly used to infer their tectonic provenance we have tested the universal applicability of the underlying principle in a small but controlled study expecting 100 confirmation of the practice a comparison is made between the chemical composition of the 1480 ma butler hill granite in an uplifted cratonic block of the st francois mountain igneous complex and that of a small 1 m thick regolith body a weathered granite sample and the basal quartz arenites of the 520 ma lamotte formation immediately above the regolith the results show that in plots of k 2 o na 2 o vs sio 2 al 2 o 3 the regolith and sandstone samples correctly plot in the passive margin field although the weathered granite plots in the arc field in plots of th sc zr 10 and la th sc the results plot in the passive and active continental margins and their extensions in other common plots to discriminate tectonic provenance e g sio 2 vs k 2 o na 2 o fe 2 o 3 mgo vs al 2 o 3 sio 2 fe 2 o 3 mgo vs tio 2 sc cr vs la y a few points plot in the passive margin field but scatter into and outside of other fields of tectonic provenances the chondrite normalized ree distributions show variable degrees of negative eu anomalies with flat hree conforming to a felsic source the lree distributions show both positive and negative ce anomalies that can be ascribed to the variability of redox conditions during weathering and diagenesis of the original siliciclastic sediments the variability of the eu anomaly was likely affected by post erosion processes in addition to whatever was inherited from the parent rocks we conclude that chemical compositions can provide good clues but are neither strong indicators nor unique identifiers of their tectonic provenance rather they indicate a dominantly felsic or dominantly mafic or a mixed set of source rocks

modal variability in the southeast pacific basin energetics of the 2009 event abstract we study the barotropic variability in the southeast pacific basin in particular focusing on the extreme event during the fourth quarter of 2009 a 3 year integration of a barotropic shallow water model forced with wind stress anomalies generates localized variability that is similar in spatial extent and amplitude as the observed anomalous event an eigenmode analysis of the same model shows the presence of several free modes in the southeast pacific but projection of the modal patterns on the model output shows that their amplitudes are low instead the mode is interpreted as an almost free mode the modal excitation accounts for a considerable fraction 23 on average of the kinetic energy input by the wind stress in the southeast pacific basin increasing to 38 for the anomalous event in 2009 surprisingly a similar but weaker event during the third quarter of 2008 appears to have been more significant from an energetics point of view with almost 50 of the energy being input into the mode key areas of energetic dissipation appear to be the eltanin fracture zone the crest of the east pacific rise and the chile rise east pacific rise intersection

influence of granitoid textural parameters on sediment composition implications for sediment generation the aim of this study is to determine and characterise the control exerted by parent rock texture on sand composition as a function of grain size the sands investigated were generated from granitoid parent rocks by the rhone damma and sidelen glaciers which drain the aar massif in the central alps switzerland and were deposited in glacial and fluvio glacial settings mechanical erosion comminution crystal breakdown and abrasion and hydraulic sorting are the most important processes controlling the generation of sediments in this environment whereas chemical and or biochemical weathering plays a negligible role by using a gis based microscopic information system mis five samples from the glacier drained portions of the aar basement have been analysed to determine textural parameters such as modal composition crystal size distribution and mineral interfaces types and lengths petrographic data of analysed sands include traditional point counts gazzi dickinson method minimum of 300 points as well as textural counts to determine interface types frequency and polycrystallinity in phaneritic rock fragments according to pettijohn s classification grain size dependent compositions vary from feldspathic litharenite 0 fraction via lithic arkose 1 and 2 to arkose 3 and 4 compositional differences among our data set were compared to modern plutoniclastic sands from the iberian massif spain and the st gabriel mts california usa which allowed us to assess the role exerted by glaciers in generating sediments by combining data from the mis with those from petrographic analysis we outlined the evolution of mineral interfaces from the parent rocks to the sediments

modal decay in the australia antarctic basin abstract the barotropic intraseasonal variability in the australia antarctic basin aab is studied in terms of the excitation and decay of topographically trapped barotropic modes the main objective is to reconcile two widely differing estimates of the decay rate of sea surface height ssh anomalies in the aab that are assumed to be related to barotropic modes first an empirical orthogonal function eof analysis is applied to almost 15 years of altimeter data the analysis suggests that several modes are involved in the variability of the aab each related to distinct areas with almost closed contours of potential vorticity second the dominant normal modes of the aab are determined in a barotropic shallow water sw model these stationary modes are confined by the closed contours of potential vorticity that surround the eastern aab and the crest of the southeast indian ridge for reasonable values of horizontal eddy viscosity and bottom friction their decay time scale is on the order of sever

a detrital heavy mineral viewpoint on sediment provenance and tropical weathering in se asia abstract understanding heavy mineral preservation is important for interpreting generation pathways provenance and geochemistry of sediments despite this many assumptions about heavy mineral stability are based on ancient strata and few studies consider modern sediments particularly those in tectonically active tropical areas such as se asia we report new heavy mineral data on 69 river sand samples from the malay peninsula and sumatra in which one aim was to find provenance indicators specific to these areas identifications were performed using optical microscopy and confirmed with sem eds in the malay peninsula heavy minerals record granitic and contact metamorphic provenance variable amounts of zircon tourmaline hornblende andalusite epidote monazite rutile and titanite and minor amounts of pyroxene apatite anatase garnet diaspore colourless spinel cassiterite and allanite are typical of this source area the composition of assemblages from sumatra indicates contributions from two major sources the modern volcanic arc i and the basement ii abundant pyroxene particularly hypersthene up to 70 is diagnostic of the volcanic arc source vesuvianite garnet andalusite tourmaline chrome spinel rutile anatase and corundum are present only in small amounts

interannual bottom pressure signals in the australian antarctic and bellingshausen basins abstractanalyses of large scale 750 km ocean bottom pressure pb fields derived from the gravity recovery and climate experiment grace and from an estimating the circulation climate of the ocean ecco state estimate reveal enhanced interannual variability partially connected to the antarctic oscillation in regions of the australian antarctic basin and the bellingshausen basin with pb magnitudes comparable to those of sea level and good correlation between the grace and ecco pb series consistent with the theory of gill and niiler the patterns of stronger pb variability are partly related to enhanced local wind curl forcing and weakened gradients in h f where h is ocean depth and f is the coriolis parameter despite weaker h f gradients motions against them are sufficiently strong to play a role in balancing the local wind input topographic effects are as or more important than changes in f additionally and contrary to the dominance of barotropic processes at subannual time scales barocl

coseismic slip distribution of the 2011 off the pacific coast of tohoku earthquake m9 0 refined by means of seafloor geodetic data 1 on 11 march 2011 the devastating m9 0 tohoku earthquake occurred on the interface of the subducting pacific plate and was followed by a huge tsunami that killed about 20 000 people several geophysical studies have already suggested that the very shallow portion of the plate interface might have played an important role in producing such a large earthquake and tsunami however the sparsity of seafloor observations leads to insufficient spatial resolution of the fault slip on such a shallow plate interface for this reason the location and degree of the slip has not yet been estimated accurately enough to assess future seismic risks thus we estimated the coseismic slip distribution based on terrestrial gps observations and all available seafloor geodetic data that significantly improve the spatial resolution at the shallow portion of the plate interface the results reveal that an extremely large greater than 50 m slip occurred in a small about 40 km in width and 120 km in length area near the japan trench and generated the huge tsunami the estimated slip distribution and a comparison of it with the coupling coefficient distribution deduced from the analysis of the small repeating earthquakes suggest that the 2011 tohoku earthquake released strain energy that had accumulated over the past 1000 years probably since the jogan earthquake in 869 the accurate assessments of seismic risks on very shallow plate interfaces in subduction zones throughout the world can be obtained by improving the quality and quantity of seafloor geodetic observations

on the wind forcing of bottom pressure variability at amsterdam and kerguelen islands southern indian ocean 1 bottom pressure records from amsterdam and kerguelen islands southern indian ocean were collected between 1986 and 1989 and interpreted previously in terms of volume transport fluctuations between the islands vassie et al 1994 since a substantial portion of the mean transport of the antarctic circumpolar current acc flows between the islands it was assumed that acc transport variability was the predominant signal being measured and comparisons with acc variability at other longitudes were made here we examine the relationship between atmospheric forcing and observed bottom pressure variability we find that kerguelen bottom pressure is forced predominantly by wind stress curl over the kerguelen plateau for periods between around 5 days and 1 year a weaker correlation with circumpolar eastward winds is observed but is seen not to be causal amsterdam pressure shows a similar local response to curl for high frequencies 5 10 days but at longer periods is sensitive to curl over the sub basin between kerguelen plateau the southeast indian ridge and antarctica this is the region of long wavelength sea level variability observed by chao and fu 1995 and interpreted in terms of a geostrophic resonance by webb and de cuevas 2002a altimetric studies confirm the usefulness of the amsterdam location in monitoring this mode we conclude that the amsterdam kerguelen pressure difference is not a useful measure of acc transport variability and that previous agreement found between variability observed here and other locations is largely fortuitous instead the series separately reflect different important dynamical modes in the southern indian ocean

high frequency barotropic ocean variability observed by grace and satellite altimetry 1 previous theoretical and model based studies of the relationship between ocean bottom pressure pb and sea level suggest primarily barotropic variability at mid to high latitudes for scales greater than a few hundred kilometers and periods less than a few months we use 7 day grace solutions and equivalent satellite altimetry maps spatially smoothed over 750 km to investigate the relation between pb and the observed fields are significantly coherent at high latitudes for periods of 14 180 days and mid latitudes for periods of 30 100 days the admittance amplitude between observed pb and is close to 1 for higher frequencies and drops off for lower frequencies the results provide for the first time global observational evidence for the barotropic nature of large scale ocean variability at mid and high latitudes we also demonstrate that grace data contain significant information over the oceans at periods 60 days i e shorter than the nominal monthly time resolution

quantitative provenance analysis of sediments review and outlook provenance analysis of sediments is aimed at reconstructing the parent rock assemblages of sediments and the climaticphysiographic conditions under which sediments formed inferring sediment provenance from the final product a basin fill is anything but straightforward because the detrital spectrum evolves as the sediment is transported along the pathway from source to basin successful provenance analysis requires that the nature and extent of compositional and textural modifications to the detrital spectrum be recognised if not quantified the history of quantification in sediment provenance studies is summarised and illustrated by tracking two fundamental ideas the concept of the sediment petrological province or petrofacies and the relation between sandstone composition and plate tectonic environment progress in sedimentary provenance analysis has been closely linked with advancements in measurement technology a brief survey of modern data acquisition tools illustrates the possibilities and limitations of modern provenance research an operational definition of quantitative provenance analysis qpa is presented in which the central role of mass balance is acknowledged extension of this definition to include quantitative predictions obtained by forward modelling computer simulation of sediment production as well as methodological improvements in data acquisition and processing is needed to cover likely future developments in qpa the contributions to the special issue quantitative provenance analysis of sediments illustrate the intrinsic multidisciplinarity and rapid expansion of qpa d 2004 elsevier b v all rights reserved

flux and fate of yangtze river sediment delivered to the east china sea numerous cores and dating show the yangtze river has accumulated about 1 16 x 10 12 t sediment in its delta plain and proximal subaqueous delta during holocene high resolution seismic profiling and coring in the southern east china sea during 2003 and 2004 cruises has revealed an elongated similar to 800 km distal subaqueous mud wedge extending from the yangtze river mouth southward off the zhejiang and fujian coasts into the taiwan strait overlying what appears to be a transgressive sand layer this distal clinoform thins offshore from similar to 40 in thickness between the 20 and 30 m water depth to 1 2 in between 60 and 90 m water depth corresponding to an across shelf distance of less than 100 km total volume of this distal mud wedge is about 4 5 x 10 11 m 3 equivalent to similar to 5 4 x 10 11 t of sediment most of the sediment in this mud wedge comes from the yangtze river with some input presumably coming from local smaller rivers thus the total yangtze derived sediments accumulated in its deltaic system and east china sea inner shelf have amounted to about 1 7 x 10 12 t preliminary analyses suggest this longshore and across shelf transported clinoform mainly formed in the past 7000 yrs after postglacial sea level reached its mid holocene highstand and after re intensification of the chinese longshore current system sedimentation accumulation apparently increased around 2000 yrs bp reflecting the evolution of the yangtze estuary and increased land erosion due to human activities such as fanning and deforestation the southward flowing china coastal current the northward flowing taiwan warm current and the kuroshio current appear to have played critical roles in transporting and trapping most of yangtze derived materials in the inner shelf and hence preventing the sediment escape into the deep ocean c 2006 elsevier b v all rights reserved

historical tsunami and storm deposits during the last five centuries on the sanriku coast japan abstract nine event deposits in a small alluvial valley along the sanriku coast japan were correlated with historical tsunamis and storms that have been recorded in this region since the 15th century we identified nine sandy layers in 15 geo slices collected at distances ranging from 140 to 260 m from the coast in a lowland back marsh protected from the sea by a high sandy ridge based on their sedimentary characteristics grain size distribution and marine microfossil assemblages namely coccoliths these event layers which were well preserved in their order of deposition were probably either tsunami or storm deposits diatom analysis revealed four stages of paleo environmental change from tidal marsh to wetland the uppermost event layer covering the ground surface is probably the deposit from the 2011 tohoku oki tsunami ages for other event deposits were radiometrically dated using 14 c 137 cs and 210 pb with bayesian estimation the second event layers can be correlated with the 1960 chilean or 1968 aomori oki earthquake tsunamis the candidates for the third event layer are the 1947 catherine and 1948 ione typhoons as well as the candidates for the second event layer the fourth and fifth event layers are likely associated with the 1933 and 1896 sanriku oki earthquake tsunamis four lower event layers can be correlated with historical tsunamis and storms that occurred during the 15th to 18th centuries such as the 1611 sanriku oki earthquake tsunami

provenance of sand on the poverty bay shelf the link between source and sink sectors of the waipaoa river sedimentary system abstract the poverty shelf north island new zealand is a segment of the waipaoa sedimentary system wss a margins source to sink focus site our petrographic analysis of sand from shelf core samples indicates that the sand fraction is mainly derived from intra and potentially extrabasinal sources but surprisingly the major fluvial system that drains into poverty bay the waipaoa river mean qfl xqyfzl is not the dominant source only one vibracore at the mouth of poverty bay contained sand qfl xqyfzl potentially derived from the waipaoa river the shelf sand mean qfl xqyfzl more strongly resembles beach sand mean qfl xqyfzl collected along the coast which is likely sourced from pervasive local cliff erosion of miocene pliocene sedimentary units that exhibit similar sandstone detrital modes mean qfl xqyfzl texturally coarser more poorly sorted and more angular sand is located along the outer shelf while finer well sorted sand characterizes the mid shelf these findings suggest a shorter transport history for the material near the outer shelf bathymetric high areas and this observation along with the composition data suggests that they were sourced by erosion of locally exposed miocene pliocene units a potential extrabasinal source of shelf sediment is indicated by anomalous prolate and equant shaped greywacke torlesse and minor red chert pebbles collected in two outer shelf box cores on the lachlan anticline these are not lithologies found within the terrestrial segment of the wss or strata comprising the outer shelf highs the clast shapes are also distinctly different from the oblate shaped pebble sized greywacke gravel clasts on beaches in hawke bay rather these sediments are more similar to torlesse stream gravel seismic and multibeam data support the possibility that during the most recent sea level lowstand the hawke bay fluvial system flowed into poverty canyon bringing these unique gravels onto what is now the poverty outer shelf the presence of the torlesse gravel is significant in that it highlights how the wss was not a closed sedimentary system in the past just as recent sedimentary research has shown in the case today

the interannual variability of the north atlantic ocean revealed by combined data from topex poseidon and jason altimetric measurements 1 a decade long record of sea surface height from combined altimeter data taken by the topex poseidon and jason satellites was analyzed for studying the interannual variability of the north atlantic ocean on time scales of 5 6 years variations of sea surface height have maximum amplitudes in three areas the subpolar gyre the gulf stream gyre the gulf stream and its recirculation and the subtropical region the variation of the subpolar gyre is 180 degrees out of phase with that of the gulf stream gyre at its eastern end the variation of the gulf stream gyre at its western end is connected to that of the subtropical region exhibiting phase propagation from the subtropics all the way to the eastern end of the gulf stream gyre the patterns of phase change suggest possible roles of rossby waves in the dynamics of the basin wide variability

impact of atmospheric intraseasonal oscillations on the indian ocean dipole during the 1990s abstract effects of atmospheric intraseasonal oscillations isos on the indian ocean zonal dipole mode iozdm are investigated by analyzing available observations and a suite of solutions to an ocean general circulation model namely the hybrid coordinate ocean model hycom data and model solutions for the period 1991 2000 are analyzed a period that includes two strong iozdm events during 1994 and 1997 and a weak one in 1991 both the data analysis and model results suggest that atmospheric isos play a significant role in causing irregularity of the two strong iozdm events and the premature termination of the weak one of particular interest is a basinwide wind driven oceanic resonance with a period near 90 days involving the propagation of equatorial kelvin and first meridional mode rossby waves across the basin before the onset of the strong 1997 dipole wind variability had significant power near 90 days and the resonance was strongly excited associated with the resonance was a deepened t

vertical tectonic crustal movements along the japanese coastlines inferred from late quaternary and recent relative sea level changes abstract observed relative sea level rsl changes during the past 130 kyr make it possible to evaluate the vertical crustal movement due to several tectonic processes such as the subduction of oceanic plates here we infer average rates of tectonic crustal movement along the japanese coastlines on three typical timescales of 50 yr 6 kyr and 125 kyr based on tide gauge and holocene rsl observations and the altitudes of marine terraces formed at the last interglacial lig phase at 125 ka the rates on a timescale of 50 yr are derived from tide gauge data thermosteric sea level changes due to thermal expansion of the oceans and predictions due to the glacio hydro isostatic adjustment gia for the last deglaciation and also recent melting of the mountain glaciers and greenland and antarctic ice sheets those for 6 kyr and 125 kyr are based on the rsl observations and the predictions by gia modelling considering uncertainties for temporal changes in eustatic sea level for the mid to late holocene and lig phase the inferred rates for 50 yr are significantly different from those for 125 kyr in most sites particularly for sites along the coastline from eastern hokkaido to northeastern japan shikoku and south kyushu facing the pacific ocean in these regions the rates for 125 kyr and 50 yr are positive uplift and negative subsidence respectively also the observed rsl changes at 6 ka are consistent with the inferred rsl changes using the rates for 125 kyr and gia predictions in many sites but inconsistent with those for 50 yr in most sites except for a few sites these results suggest that the rates on a timescale of 50 yr are not representative of the tectonic crustal movements for timescales longer than 6 kyr in most sites along the japanese coastlines however the inferred rates on these timescales may be useful in discussing the recurrence of megathrust earthquake with its interval of 1 kyr such as the 2011 earthquake off the pacific coast of tohoku

from gullies to mountain belts a review of sediment budgets at various scales this paper reviews the state of the art in the concept as well as in the application of sediment budgets in sedimentary research sediments are a product of mass dispersal at the earth surface and take part in global cycles sediment budgets aim at quantifying this mass transfer based on the principle of mass conservation and are the key to determine ancient fluxes of solid matter at the earth surface this involves fundamental questions about the interplay of uplift climate and denudation in mountain belts and transfer of sediments from the continents to the oceans as well as applied issues such as soil and gully erosion reservoir siltation and coastal protection first after introducing basic concepts relevant scales and methodologies the different components of quaternary routing systems from erosion in headwaters river systems glacial and paraglacial systems lakes deltas estuaries coasts shelves epicontinental seas and deep sea fans are discussed in terms of their sediment budget most suitable are sedimentologically closed or semi closed depositional environments e g alluvial fans lakes deltas and deep sea fans in a second step the dynamics of passive active and collisional tectonic settings and sediment budgets in related sedimentary basins are explored and new concepts of sediment portioning at large geodynamic scales are introduced ancient routing systems are more or less incomplete and may be intensively fragmented or destroyed in active tectonic settings in terms of sedimentary basin types rifts intracontinental and epicontinental settings are preferred objects of sediment budgets because of their persistence and relatively simple overall sedimentary architecture however closing basins such as foreland forearc retroarc piggy back and wedge top basins may provide excellent snapshots of orogenic sediment fluxes in a third step the large long lived routing systems of the amazon the ganges brahmaputra and the rhine are reviewed for each system estimates of either sediment volumes mass or sediment fluxes of continental and marine subsystems have been compiled in order to receive a complete routing in terms of mass conservation for specific time periods since the late glacial maximum as well as the cenozoic following lessons can be taken from these case studies i depositional centers and fluxes show strong shifts in space and time and call for caution when simply looking at subsystems ii the response times of these large systems are within the milankovich time interval thus lower than predicted from diffusion models iii cyclic routing of sediments in continental basins is much more dominated by climate human control than by eustacy and iv at long time scales ultimate sinks win over intermittent storage it is concluded from this review that the quantitative understanding of global sediment cycling over historic and geologic time and its response to allogenic forcing is still in its infancy and further research is needed towards a holistic view of sediment routing systems at various temporal and spatial scales and their coupling with global biogeochemical cycles this includes i to better determine response times of large routing systems by linking quaternary with cenozoic sediment budgets and continental with marine sub systems ii to combine advanced provenance techniques with sediment budgets in order to reconstruct ancient systems iii to study sediment partitioning at the basin scale iv to reconcile continental supply dominated sequence stratigraphy with the eustatic dominated marine concept and iv to account for non actualism of ancient systems with respect to their erosion and transport mode in particular during glaciations and pronounced arid intervals glacial and eolian sediment routing may cross over hydrologic boundaries of drainage basins thus challenging the principle of mass conservation

incised valley fill succession affected by rapid tectonic uplifts an example from the uppermost pleistocene to holocene of the isumi river lowland central boso peninsula japan abstract the burial history of the isumi river lowland was reconstructed based on a facies analysis of borehole and geoslicer samples undisturbed sediment samples collected by 4 0 m long 0 35 m wide and 0 01 to 0 05 m deep wedge shaped steel case together with an analysis of molluscan shell assemblages for environmental assessment and 14c age measurements the borehole successions constitute a part of a depositional sequence in a fluvial and wave dominated incised valley the facies succession and age data suggest that the lower part of the succession before 7 0 calendar kilo years before present cal ky bp has in a broad scale an aggradational to retrogradational stacking pattern although a short period of sediment progradation occurred during 9 0 8 5 cal ky bp the upper part 7 0 cal ky bp present is a prograding succession of beach shoreface and bayhead delta sediments deposited in an enclosed bay environment ca 3 5 cal ky bp the facies changes from an open to an enclosed marine environment resulted from barrier formation age measurements indicate that the choja and izumi terrace surfaces formed some time after 6 5 cal ky bp and around 3 5 cal ky bp respectively the temporary progradation during 9 0 8 5 cal ky bp was probably associated with several meters of tectonic uplift which resulted in an increase in the sediment supply owing to intensified fluvial and marine erosion after a tectonic uplift at about 6 4 ky bp a wide strand plain started to form along the bay shore as a result of sediment transport from both north and south of the bay by longshore currents however a barrier developed about 3 5 cal ky bp after the izumi surface was uplifted subsequently this uplift transported sediments probably bypassed the southern part of the lowland and accumulated near the mouth of the bay to form this barrier as is indicated by the poor strand plain development after this time strand plain progradation might have been prevented by strong wave influences from the pacific ocean and longshore currents resulting from both the recession of the sea cliffs south and north of the lowland and from the uplift which shifted the shoreline seaward and changed the shoreline environment from an enclosed bay into a more open marine environment

recurrence of postseismic coastal uplift kuril subduction zone japan 1 coastal stratigraphy of eastern hokkaido indicates that decimeters of coastal uplift occurred repeatedly in the late holocene employing radiocarbon dating and tephrochronology we identify along a 100 km length of the kuril subduction zone six uplift events since 2 800 years b p uplift events occur at the same frequency as unusually high tsunamis each coastal uplift event which occurs on average every 500 years is the product of decade long post seismic deep slip on the down dip extension of the seismogenic plate boundary following an offshore multi segment earthquake that generates unusually high tsunamis

subsidence along the central to southern sanriku coast northeast japan near the source region of the 2011 tohoku oki earthquake estimated from the holocene sedimentary succession along a ria coast abstract along the sanriku coast northeast japan discrepancies in crustal movement have been reported between uplift on a scale of 105 years versus subsidence on a scale of 101 102 years well dated holocene incised valley fill sediments provide records of millennial scale vertical crustal movement which is key to understanding the tectonic history in this area previous studies of the age and distribution of early holocene intertidal deposits in incised valleys reported that the southern sanriku coast has subsided during the holocene at an average rate of about 1 mm yr here we studied three sediment cores tgi1 tgi2 and tgi3 collected from the tsugaruishi plain on the central sanriku coast and recognized a holocene deltaic sediment succession in all three cores in core tgi3 from the farthest inland site the intertidal sediment facies deposited from 7500 to 7000 cal bp and the overlying 6 m thick floodplain facies deposited from 7000 to 5000 cal bp are both below the present sea level because a sea level highstand due to hydroisostatic uplift around japan occurred in the mid holocene we inferred that the tsugaruishi plain subsided during the holocene and the estimated subsidence rate 1 1 1 9 mm yr at maximum is consistent with the recently reported subsidence rate along the southern sanriku coast the results of this study confirm that the central to southern sanriku coast is subsiding in contrast to an interpretation based on the study of marine terraces that this part of the coast is uplifting the empirical data presented here will be useful for constructing an earthquake cycle model related to plate subduction

a note on the barotropic response of sea level to time dependent wind forcing this study examines the extent to which sea level variations at periods between 30 days and 1 year and spatial scales greater than 1000 km can be described by the wind driven linear barotropic vorticity dynamics the topex poseidon altimetric observations of sea level and the wind products of the national meteorological center are used as the database for the study each term of the linear barotropic vorticity equation was evaluated by averaging over regions of 10 10 in most of the open ocean the result of the analysis suggests that the sea level variabilities at the scales considered cannot be fully described by the equation the apparent net vorticity change is more than what can be explained by the local wind stress curl in the few regions where the wind stress curl is strong enough to balance the vorticity budget predominantly in the northeast pacific and the southeast pacific the balance is basically achieved in terms of the time dependent topographic sverdrup relation namely the balance between the advection of the planetary vorticity plus the topography induced vorticity and the forcing by the wind stress curl

25 day period large scale oscillations in the argentine basin revealed by the topex poseidon altimeter the measurement of the global sea surface height made by the topex poseidon satellite has provided the first synoptic view of large scale oceanic variability at intraseasonal scales from weeks to months areas of significant intraseasonal variability were found primarily in the tropics and the high latitude oceans the southern ocean in particular the focus of the paper is the finding of large scale oscillations at a period of 25 days in the argentine basin of the south atlantic ocean these oscillations exhibit a dipole pattern of counterclockwise rotational propagation centered at 458s 3178e over the zapiola rise the scale of the dipole is about 1000 km the peak to trough amplitude is on the order of 10 cm the amplitude of these oscillations has large seasonalto interannual variations these oscillations are shown to be associated with a free barotropic mode of the basin as a solution to a linearized barotropic vorticity equation closed f h contours provide a mechanism for the confinement of the waves to the topographic feature of the zapiola rise results from a numerical model simulation reproduced the patterns of the observed oscillations the resultant mass transport variability is on the order of 50 sv sv 106 m3 s21 deep current meters in the argentine basin reveal signals consistent with the altimetry observations

decadal variability in the large scale sea surface height field of the south pacific ocean observations and causes large scale sea surface height ssh changes in the extraequatorial south pacific ocean are investigated using satellite altimetry data of the past 12 yr the decadal ssh signals in the 1990s were dominated by an increasing trend in the 30 50 s band and a decreasing trend in the central south pacific ocean poleward of 50 s in recent years since 2002 there has been a reversal in both of these trends spatially varying low frequency ssh signals are also found in the tropical region of 10 25 s where the decadal ssh trend is negative in the eastern basin but positive in the western basin to clarify the causes for these observed spatially varying ssh signals a 11u2 layer reduced gravity model that includes the wind driven baroclinic rossby wave dynamics and the responses forced by ssh changes along the south american coast was adopted the model hindcasts the spatially varying decadal trends in the midlatitude and the eastern tropical regions well accumulation of the wind forced ssh anomalies along rossby wave characteristics is found to be important for both previously reported long term trends and their reversals in recent years the boundary forcing associated with the time varying ssh signals along the south american coast is crucial for understanding the observed ssh signals of all time scales in the eastern tropical south pacific basin but it has little impact upon the midlatitude interior ssh signals

the intraseasonal oscillation in eastern pacific sea levels how is it forced abstract daily sea level and surface winds at eastern pacific shore locations and equatorial islands together with gridded five day averages of 850 mb winds have been analyzed for the 1979 84 period to determine how the 40 60 day intraseasonal oscillation of eastern pacific sea levels is forced as described by spillane et al for 1971 75 the oscillation was also present in 1980 84 from callao peru to san francisco with maximum energy near 52 57 days and band limits of 43 and 65 days during 1980 84 there was no evidence for forcing of the large scale oscillation in the eastern pacific although a local contribution of forcing was superimposed on the remote signal at the california stations interannual fluctuations in amplitude were evident in the sea level time series consistent with those of the corresponding wind oscillation in the western equatorial pacific the oscillation was best developed in both variables in 1980 82 and became weak or nonexistent during the recovery phase of the 1982 83 e

coseismic and pre seismic subsidence associated with great earthquakes in alaska abstract alternating beds of peat and mud in sediment sequences on the south central alaskan coast record coseismic and inter seismic relative land and sea level movements caused by repeated great earthquakes on the alaska aleutian subduction zone during the ad 1964 mw 9 2 earthquake tidal marshes and wetlands around upper cook inlet experienced up to 2 m of subsidence burying peat forming communities with intertidal mud here we use quantitative analyses of fossil diatoms within peat mud couplets to reconstruct land sea level changes for the 1964 and five earlier great earthquakes during the past 3300 years in contrast to geodetic observations that are limited to the present post seismic phase we quantify varying spatial patterns of uplift and subsidence through complete earthquake cycles relative land uplift characterises most of the inter seismic phase of each cycle at our sites whereas each great earthquake was preceded by a short period of pre seismic relative land subsidence

composition and provenance of late pleistocene holocene alluvial sediments of the eastern andean piedmont between 33 and 34 s mendoza province argentina abstract the andean cordillera and its piedmont in the central western argentina has been long considered as one of the main source areas of detritus for the chaco pampean plain sand dune fields and loess loess like deposits of central argentina the main goal of this study is to evaluate the composition of the late pleistocene holocene alluvial deposits of the andes cordillera piedmont from 33 to 34 s the results are interpreted in the context of the regional geology tectonic setting of the study area and its implications in the continent wide perspective of modern alluvial sands proposed by potter 1994 sampling was conducted at the alluvial stratigraphic sequences of four study sites along three andean piedmont arroyos modal mineralogy in the very fine sand fraction 3 phi to 4 phi was determined using standard petrographic microscope methods q f lf average compositions indicate that the late pleistocene holocene very fine grained alluvial sands of the cordillera frontal piedmont reflects the modern lithic arenites of the argentine association reported by potter 1994 the results show two geologically distinct sources in the catchment areas volcaniclastic and metamorphic rocks high concentrations of mica and volcanic glass are likely related to particle morphologies and to the deposition sedimentary environment recorded in the alluvial sequences floodplains the overabundance of micas over the volcanic glass in the mid late holocene alluvial sequence indicates the drainage of a metamorphic area at the expense of other lithological sources source areas are located mainly in the frontal cordillera and to a lesser extent in the piedmont tertiary deposits another likely source for the analyzed quaternary alluvial sediments the mineralogical signature of the late pleistocene and holocene alluvial sequences is in agreement with the composition of the southern pampean sand mantles loess and loess like deposits mainly formed by a volcanic mineral assemblage with source areas placed at the headwaters of the main andean rivers

ocean dynamics associated with rapid j2 fluctuations importance of circumpolar modes and identification of a coherent arctic mode 1 fluctuations of the earth s dynamic oblateness j2 are a measure of global redistributions of mass between equatorial and polar regions sensitive to the component which is symmetric about the equator cox and chao recently published a time series of monthly values of j2 based on satellite orbit determination which showed rapid fluctuations from month to month as well as a large change in j2 in 1997 1998 we here investigate the ocean dynamics associated with these rapid fluctuations using a barotropic ocean model forced by atmospheric wind stress and pressure we find that the model has significant skill in reproducing the observations though not the change in 1997 1998 much of the model variability is related to coherent circumpolar fluctuations in arctic and antarctic bottom pressure which despite their apparent symmetry are forced by quite different mechanisms the antarctic mode is forced by circumpolar winds whereas the arctic mode is forced by northward winds over the entrances to the polar sea comparison with in situ observations shows that the model has skill in reproducing the polar modes arctic tide gauge records confirm the presence of a coherent mode at short periods and at long periods over at least the eurasian arctic shelf if barotropic and representative of the whole arctic this would be large enough to make a major contribution to measured j2 fluctuations but does not account for the 1997 1998 event

de aliasing of global high frequency barotropic motions in altimeter observations theexistenceofhighfrequency periodsshorter than 10 days energetic barotropic motions in the ocean is shown to lead to a large aliasing error in satellite altimetric observations this error is most easily seen in the tracki ness of 10 day altimetric maps and commonly attributed to orbit error fortunately existing ocean general circula tion models when driven with twice daily windstresselds have considerable skill in predicting these motions with improved forcing and models we can expect that in the fu ture the alias can be largely suppressed by subtracting the model generated high frequency elds

secular and earthquake related vertical crustal movements in japan as deduced from tidal records 1951 1981 abstract monthly tidal records for the last 31 years from about 100 tidal stations are used to delineate vertical crustal movements in japan a new computer aided processing system was created for this purpose its principle is differential use of tidal records in a region so that the oceanographic disturbances of common causes may be eliminated from the sea level data this method enables us to observe nearly absolute vertical land movement at tidal stations with a precision of a few centimeters the japanese islands are divided into nine regions taking oceanographic conditions into account general discussion on recent vertical movements has yielded several notable features and trends as follows 1 1 rapid and stationary subsidence in the northeastern part of japan presumably of tectonic origin 2 2 a complex pattern of uplift and subsidence in the southwestern part of japan which seems to reflect subduction of the philippine sea plate against the honshu block 3 3 relatively stable land on the japan sea side of honshu movements related to the earthquakes during the period 1951 1981 are also discussed although few of the cases show clear cut premonitory movements if abnormal movements in a coastal area appeared with an amplitude exceeding 2 or 3 cm we could detect them by the present system

the 2011 tohoku oki earthquake displacement reaching the trench axis we detected and measured coseismic displacement caused by the 11 march 2011 tohoku oki earthquake moment magnitude mw 9 0 by using multibeam bathymetric surveys the difference between bathymetric data acquired before and after the earthquake revealed that the displacement extended out to the axis of the japan trench suggesting that the fault rupture reached the trench axis the sea floor on the outermost landward area moved about 50 meters horizontally east southeast and 10 meters upward the large horizontal displacement lifted the sea floor by up to 16 meters on the landward slope in addition to the vertical displacement

role of lichens in weathering of granodiorite in the sila uplands calabria southern italy this paper explores the role of five recurrent epilithic lichen species aspicilia intermutans nyl arnold xanthoparmelia pulla ach o blanco a crespo elix d hawksw lumbsch rhizocarpon lecanorinum anders tephromela atra huds hafellner and lecanora bolcana pollini poelt which encrust granodiorite spheroidal boulders exposed in the sila uplands calabria southern italy in weathering of plutonic rocks in a typical mountainous mediterranean environment a detailed investigation was carried out on the lichen rock interface of each species by comparing them mutually and with lichen free granodiorite samples for this purpose the lichen species were sampled together with the encrusted rock surface for detailed mineral petrographic analyses performed in thin and ultra thin sections optical and scanning electron microscopy of these sections and of bulk samples permitted us to highlight the peculiar modes of physical and chemical attacks of lichen thalli and hyphae on and into the substratum for each species crack systems often parallel to the outer rock surface appear often intruded by hyphae which cause rupture of primary minerals with detachment and progressive incorporation of their fragments into the thallus in particular the species l bolcana and t atra revealed an unexpected partly endolithic behavior presumably enhanced by the presence of rock fractures earlier generated by other physical breakage processes already affecting the spheroidal boulders in the sila mountains dissolution features often affect primary minerals even quartz that may show very peculiar patterns which are suggestive of a biologically induced control various phyllosilicate clay minerals were identified using sem eds microprobe analyses and ft ir spectroscopy which also enabled the identification of possible amorphous silica or quartz micrograins rhizocarpic acid and carotenoid at the encrusted granodiorite interface in contrast neither oxalic acids nor oxalates were detected

introduction to the special issue actualistic models of sediment generation conceptual models in sedimentary petrology that relate verticaland lateral compositional signatures during the lling of sedimentarybasins to their internal and external control factors have beendeveloped in the 80 ies and 90 ies of the last century althoughre ned petrographic and geochemical analyses have focussed ondeciphering complex events in time and space such as tectonic evo lution of source terranes changes in sediment dispersal patterns orpalaeoclimate uctuations quantitativemodelsarestillintheirinfancy despite a long history of research one reason for this state of affairs isthe strong interdisciplinary nature of the subject matter another isthe lack of appropriate modelling tools capable of dealing with thecomplex nature of sediment properties the recent proliferation ofquantitative data acquisition techniques coupled with progress indata processing and modelling approaches has led to the emergenceof a new eld of study aimed at solving the fundamental problem ofreconstructing mass transfer from source areas to sedimentary basins the term sediment generation acts as a convenient umbrella for thecomplex web of processes acting between source and sink quantitative models of sediment generation aim at providing anassessment of the type amount and rateof supplyof detritalmaterialfrom identi able parent rock assemblages to a basin ll in order toful l this objective two key questions must be addressed i how much sediment is being delivered ii what are the compositional and textural characteristics of thesediment the rst question is intimately connected to sediment budget as sessments and their derivative with respect to time i e erosion ordenudation and sedimentation rates the second one refers to the

great earthquake paleogeodesy and tsunamis of the past 2000 years at alsea bay central oregon coast usa the width of plate boundary fault rupture at the cascadia subduction zone a dimension related to earthquake magnitude remains uncertain because of the lack of quantitative information about land level movements during past great earthquake deformation cycles beneath a marsh at alsea bay on the central oregon coast four sheets of tsunami deposited sand blanket contacts between tidal mud and peat radiocarbon ages for the sheets match ages for similar evidence of regional coseismic subsidence and tsunamis during four of cascadia s great earthquakes barring rapid unrecorded postseismic uplift reconstruction of changes in land level from core samples using diatom and foraminiferal transfer functions includes modest coseismic subsidence 0 470 2 m during the four earthquakes interpretation is complicated however by the 30 38 of potentially unreliable transfer function values from samples with poor analogs in modern diatom and foraminiferal assemblages reconstructions of coseismic subsidence using good analog samples range from 0 4670 12 to 0 0970 20 m showing greater variability than implied by sample specific errors from apparent high rates of land uplift following subsidence and tsunamis we infer that postseismic rebound caused by slip on deep parts of the plate boundary and or viscoelastic stress relaxation in the upper plate may be almost as large as coseismic subsidence modest coseismic subsidence 100 km landward of the deformation front implies that plate boundary ruptures in central oregon were largely offshore ruptures may have been long and narrow during earthquakes near magnitude 9 as suggested for the ad 1700 earthquake or of smaller and more variable dimensions and magnitudes r 2008 elsevier ltd all rights reserved

paleogeodetic records of seismic and aseismic subduction from central sumatran microatolls indonesia we utilize coral microatolls in western sumatra to document vertical deformation associated with subduction microatolls are very sensitive to fluctuations in sea level and thus act as natural tide gauges they record not only the magnitude of vertical deformation associated with earthquakes paleoseismic data but also continuously track the long term aseismic deformation that occurs during the intervals between earthquakes paleogeodetic data this paper focuses on the twentieth century paleogeodetic history of the equatorial region our coral paleogeodetic record of the 1935 event reveals a classical example of deformations produced by seismic rupture of a shallow subduction interface the site closest to the trench rose 90 cm whereas sites further east sank by as much as 35 cm our model reproduces these paleogeodetic data with a 2 3 m slip event on the interface 88 to 125 km from the trench axis our coral paleogeodetic data reveal slow submergence during the decades before and after the event in the areas of coseismic emergence likewise interseismic emergence occurred before and after the 1935 event in areas of coseismic submergence among the interesting phenomenon we have discovered in the coral record is evidence of a large aseismic slip or silent event in 1962 27 years after the 1935 event paleogeodetic deformation rates in the decades before after and between the 1935 and 1962 events have varied both temporally and spatially during the 25 years following the 1935 event submergence rates were dramatically greater than in prior decades during the past four decades however rates have been lower than in the preceding decades but are still higher than they were prior to 1935 these paleogeodetic records enable us to model the kinematics of the subduction interface throughout the twentieth century

wind forced intraseasonal sea level variability of the extratropical oceans abstract seven years worth of sea level observations from the topex poseidon altimeters and wind observations from the european remote sensing satellites ers 1 2 scatterometers were used to investigate the dynamics of large scale intraseasonal sea level variability at mid and high latitudes coherent patterns of sea level variability with spatial scales of 1000 km and timescales of 20 days to 1 year are identified in three particular regions the bellingshausen basin west of drake passage the australian antarctic basin and the central north pacific ocean 30 50 n near the date line significant coherence is found between wind stress curl and the sea level variability a simple barotropic vorticity equation in which the time rate of relative vorticity variation is balanced by the wind stress curl and a damping term is used to simulate the sea level anomalies with a significant degree of correlation with the observations although the coherence between the simulation and the observation is signifi

the role of vorticity fluxes in the dynamics of the zapiola anticyclone 1 the argentine basin in the south atlantic ocean is one of the most energetic regions in the ocean with complicated dynamics which plays an important role in the global climate a number of observations have discovered an intense anticyclonic gyre of barotropic circulation around the zapiola rise in the center of the basin theoretical studies have shown that the zapiola anticyclone represents an eddy driven flow controlled by bottom friction recent advances in high resolution global ocean data syntheses performed using nasa supercomputing facilities provide realistic simulations of the circulation and the variability in the argentine basin using these simulations and satellite altimeter observations we analyzed the vorticity balance of the zapiola anticyclone our results suggest the dominance of vorticity fluxes and the advection of the potential vorticity over a nonuniform bottom topography in determining the variability of the gyre while the impact of the local wind stress is small the divergence of the relative vorticity anomaly advection by eddies is found to be the most important contributor to the relative vorticity flux divergence influencing the variability of the zapiola anticyclone our results demonstrate that the relative vorticity influencing the variability of the anticyclone is mainly advected from the south where the northern branch of the antarctic circumpolar current at the subpolar front is located

fragmentary evidence of great earthquake subsidence during holocene emergence valdivia estuary south central chile a reconnaissance of holocene stratigraphy beneath fringing marshes of the valdivia estuary where an m 9 5 earthquake caused 1 2 m of regional coseismic subsidence in 1960 shows only fragmentary evidence of prehistoric coseismic sub sidence in most of the 150 hand driven cores that were examined a distinct uncon formity separates 0 5 1 5 m of late holocene tidal and floodplain mud peat and sand from underlying middle holocene subtidal mud and sand at the las coloradas site where stratigraphy is best preserved two a horizons of marsh and meadow soils abruptly overlain by sand and mud probably record coseismic subsidence shortly fol lowed by tsunamis the amount of subsidence during the earthquakes proved difficult to reconstruct with a diatom transfer function because of differences between modern and fossil diatom assemblages maximum 14 c ages on macrofossils from the two a horizons at the las coloradas site of 1 7 1 3 ka and 2 7 1 7 ka allow correlation of the younger horizon with either of two of six 14 c dated a horizons buried by tsunami sand or post tsunami tidal sand 200 km to the south at maullin and with a lake wide mass wasting event in lago puyehue 100 km to the southeast tidal records of prehistoric coseismic subsidence at valdivia are scarce because of a sea level fall of 3 8 m over the past 6000 years erosion of marsh and meadow soils during subsidence induced flooding of the estuary and largely complete land level recovery during cycles of coseismic subsidence and postseismic uplift online material diatom species data from the las coloradas site valdivia estuary

dynamics of sea surface temperature anomalies in the southern ocean diagnosed from a 2d mixed layer model we analyze the processes responsible for the generation and evolution of sea surface temperature anomalies observed in the southern ocean during a decade based on a 2d diagnostic mixed layer model in which geostrophic advection is prescribed from altimetry anomalous air sea heat flux is the dominant term of the heat budget over most of the domain while anomalous ekman heat fluxes account for 20 40 of the variance in the latitude band 40 60 s in the acc pathway lateral fluxes of heat associated with anomalous geostrophic currents are a major contributor dominating downstream of several topographic features reflecting the influence of eddies and frontal migrations a significant fraction of the variability of large scale sst anomalies is correlated with either enso or the sam each mode contributing roughly equally the relation between the heat budget terms and these climate modes is investigated showing in particular that anomalous ekman and air sea heat fluxes have a co operating effect with regional exceptions hence the large sst response associated with each mode it is further shown that enso or sam locked anomalous geostrophic currents generate substantial heat fluxes in all three basins with magnitude comparable with that of atmospheric forcings for enso and smaller for the sam except for limited areas enso locked forcings generate sst anomalies along the acc pathway and advection by mean flows is found to be a non negligible contribution to the heat budget exhibiting a wavenumber two zonal structure characteristic of the antarctic circumpolar wave by contrast sam related forcings are predominantly zonally uniform along the acc hence smaller zonal sst gradients and a lesser role of mean advection except in the southwest atlantic while modeled sst anomalies are significantly correlated with observations over most of the southern ocean the analysis of the data model discrepancies suggests that vertical ocean physics may play a significant role in the nonseasonal heat budget especially in some key regions for mode water formation

adjustment of the southern ocean to wind forcing on synoptic time scales abstract this study addresses the response of the southern ocean to high frequency wind forcing focusing on the impact of several barotropic modes on the circumpolar transport a suite of experiments is performed with an unstratified model of the southern ocean forced with a stochastic wind stress that contains a large range of frequencies with synoptic time scales the southern ocean adjustment displays a different character for frequencies below and above 0 2 cpd the low frequency range is dominated by an almost free mode response in the region where contours of f h are obstructed by only a few bathymetric features the truly free mode only plays a minor role topographic form stress rather than friction is the dominant decay mechanism of the southern mode it leads to a spindown time scale on the order of 3 days for the high frequency range the circumpolar transport is dominated by the resonant excitation of oscillatory modes the active response of the ocean leads to strong changes and eve

the 1964 great alaska earthquake present day and cumulative postseismic deformation in the western kenai peninsula abstract global positioning system gps triangulation and leveling data are used to derive models for the present day last 5 years and the 30 year average postseismic deformation on the kenai peninsula alaska following the 1964 alaska earthquake the two datasets are inverted using a three dimensional elastic dislocation model to estimate the magnitude and spatial distribution of slip on the north america pacific plate interface allowing us to examine the time dependence of the processes controlling postseismic deformation we determine that the 30 year average postseismic slip rate beneath the western kenai peninsula was about twice as large as the present day slip rate the observations suggest a time decaying process but are not consistent with a single exponentially decaying relaxation process initiated immediately after the 1964 earthquake we conclude that the postseismic deformation observed on the western kenai peninsula cannot be explained in terms of any single time decaying process either multiple processes acting on different timescales or significant spatial propagation of the postseismic deformation or both must occur in the latter case postseismic deformation would not begin everywhere at the same time and the rate of spatial propagation would affect the timescale inferred for the postseismic processes

modelling the joint variability of grain size and chemical composition in sediments abstract the geochemical composition of siliciclastic sediments correlates strongly with grain size hence geochemical composition may serve as a grain size proxy in the absence of grain size variations geochemical data of siliciclastic sediments may be used to characterise size independent processes i e sediment provenance weathering mixing shape density sorting and diagenesis in general however geochemical data sets contain both types of information in order to formalise interpretation of geochemical data we propose a mathematical method to decompose the total geochemical variability of a series of genetically related specimens into a grain size dependent the shared signal and a grain size independent part the residual signal the former may serve as a proxy for grain size whereas the latter represents geochemical variability that would have been observed if all sediments would have had the same grain size distribution the two data sets are jointly decomposed by means of partial least squares pls and orthogonal projection subsequently the presence of significant grain size independent geochemical variability in the residual signal is determined in a statistically rigorous manner using a 2 test using a synthetic example we show that the residual record effectively reveals an imposed provenance signal which could not have been resolved from the geochemical or grain size data sets individually we analysed the relation between grain size and geochemical composition in three quaternary marine sediment cores located offshore west africa and south america geob7920 2 geob9508 5 and geob7139 2 both sites are characterised by biogenic sediment input in addition to fluvial and aeolian sediment input from the continent it was found that all cores show a strong but different correlation between the mean grain size and the bulk geochemical composition these results demonstrate that geochemical grain size proxies are empirical and site specific it was also found that the geochemical and grain size data in cores geob7920 2 and geob7139 2 do not contain unique information whereas in core geob9508 5 ti varies independently from the grain size this residual ti signal correlates with the transport mechanism as demonstrated by statistically different values of aeolian and fluvial dominated sediments however a unique interpretation of this residual signal in terms of the postulated grain size independent mechanisms could not be provided without additional information we conclude that the proposed model facilitates identification and validation of different element ratios as grain size proxies and more importantly as proxies for size independent processes for this reason the model paves the way for rigorous analysis of multi proxy data which are widely used in palaeoceanographic and palaeoclimatic research

uses and misuses of compositional data in sedimentology this paper serves two goals the first part shows how mass evolution processes of different nature become undistinguishable once we take a size limited noisy sample of its compositional fingerprint processes of exponential decay mass mixture and complementary accumulation are simulated and then samples contaminated with noise are extracted the aim of this exercise is to illustrate the limitations of typical graphical representations and statistical methods when dealing with compositional data i e data in percentages concentrations or proportions the second part presents a series of concepts tools and methods to represent and statistically treat a compositional data set attending to these limitations the aim of this second part is to offer a state of the art compositional data analysis this includes descriptive statistics and graphics the biplot ternary diagrams with confidence regions for the mean regression and analysis of variance models to explain compositional variability and the use of compositional information to predict environmental covariables or discriminate between groups all these tools share a four step algorithm 1 transform compositions with an invertible log ratio transformation 2 apply a statistical method to the transformed scores 3 back transform the results to compositions and 4 interpret results in relative terms using these techniques a data set of sand petrographic composition has been analyzed highlighting that finer sands are richer in single crystal grains in relation to polycrystalline grains and that grain size accounts for almost all compositional variability a stronger water flow river discharge favors mica grains against quartz or rock fragment grains possibly due to hydrodynamic sorting effects a higher relief ratio implies shorter residence times which may favor survival of micas and rock fragments relatively more labile grains

long term and short term vertical velocity profiles across the forearc in the ne japan subduction zone abstract we estimated the long term vertical velocity profile across the northeastern japan forearc by using the height distribution of late quaternary marine and fluvial terraces and we correlated the ages of the two marine terraces with marine isotope stages mis 5 5 and 5 3 or 5 1 by cryptotephra stratigraphy the uplift rate estimated as 0 11 0 19 m ka 1 from the relative heights between the terrace surfaces and eustatic sea levels was nearly equal to or slightly slower than the uplift rate farther inland 0 15 0 19 m ka 1 as determined from the relative heights of fill terrace surfaces in contrast the short term vertical velocity profile obtained from gps observations showed that the forearc is currently subsiding at a maximum rate of 5 4 0 4 mm yr 1 thus the current short term geodetic subsidence does not reflect long term geological tectonic movement short term vertical deformation is probably driven by subduction erosion or elastic deformation caused by interplate coupling or both however long term uplift is probably due not to moment release on the mega thrust but to crustal thickening

large scale variability in the midlatitude subtropical and subpolar north pacific ocean observations and causes abstract altimetric data from the 8 yr topex poseidon t p mission oct 1992 jul 2000 are used to investigate large scale circulation changes in the three current systems of the midlatitude north pacific ocean the north pacific current npc the alaska gyre and the western subarctic gyre wsg to facilitate the understanding of the observed changes a two layer ocean model was adopted that includes first mode baroclinic rossby wave dynamics and barotropic sverdrup dynamics the npc intensified steadily over the t p period from 1992 to 1998 much of this intensification is due to the persistent sea surface height ssh drop on the northern side of the npc a similar ssh trend is also found in the interior of the alaska gyre both of these ssh changes are shown to be the result of surface wind stress curl forcing accumulated along the baroclinic rossby wave characteristics initiated from the eastern boundary in addition to the interior ssh signals the intensity of the alaska gyre is shown to depend

the partition of regional sea level variability abstract the existing altimetric record offers an unprecedented view of sea level variability on a global scale for more than 2 decades optimal inference from the data involves appropriate partition of signal and noise in terms of relevant scales physical processes and forcing mechanisms such partition is achieved here through fitting a general circulation model to altimeter and other datasets to produce a best estimate of variability directly forced by the atmosphere the signal of primary interest here in this context noise comes primarily from instrument errors and meso scale eddies as expected but spatial smoothing effectively reduces this noise a separate constraint is thus formulated to measure the fit to monthly large scale altimetric variability that unlike the daily pointwise constraint shows a high signal to noise ratio the estimate is explored to gain insight into dynamics forcing and other factors controlling variability contributions from thermo steric halo steric and bottom pressure terms are all important depending on region but slopes of steric spectra red and bottom pressure spectra white are nearly invariant with latitude much variability can be represented by a seasonal cycle and linear trend plus a few eofs that can be associated with known modes of climate variability and or with topographic controls both wind and buoyancy forcing are important the response is primarily basin bound in nature but uneven patterns of propagation across basin boundaries are clearly present with the pacific being able to affect large portions of the indian and atlantic basins but the atlantic affecting mostly the arctic

eastern mediterranean tectonics and tsunami hazard inferred from the ad 365 earthquake historical accounts describe an earthquake and tsunami on 21 july ad 365 that destroyed cities and drowned thousands of people in coastal regions from the nile delta to modern day dubrovnik the location and tectonic setting of this earthquake have been uncertain until now here we present evidence from radiocarbon data and field observations that western crete was lifted above sea level by up to 10 m synchronously with the ad 365 earthquake the distribution of uplift combined with observations of present day seismicity suggest that this earthquake occurred not on the subduction interface beneath crete but on a fault dipping at about 30 within the overriding plate calculations of tsunami propagation show that the uplift of the sea floor associated with such an earthquake would have generated a damaging tsunami through much of the eastern mediterranean measurement of the present rate of crustal shortening near crete yields an estimate of 5 000 yr for the repeat time of tsunamigenic events on this single fault in western crete but if the same process takes place along the entire hellenic subduction zone such events may occur approximately once every 800 yr in the year ad 365 an earthquake and tsunami destroyed much of the eastern mediterranean coastal regions the distribution of uplift at the time suggests that the earthquake occurred on a fault within the overriding plate at the subduction zone beneath crete and not on the subduction interface itself

weathering and mineralogical evolution in a high alpine soil chronosequence a combined approach using sem edx cathodoluminescence and nomarski dic microscopy abstract physical and chemical weathering of primary minerals of granitic till in the proglacial area of morteratsch switzerland was investigated using cathodoluminescence cl nomarski differential interference contrast dic microscopy and scanning electron microscope sem edx the investigated time span ranges from 0 to 140 years of sediment exposure for the very early stage of weathering or soil formation only little information is available the main aim of our investigation was consequently to see whether weathering of primary minerals can be detected in such a short time span using for the first time for soils well established methods as cl and nomarski dic microscopy in geo and material science such for that purpose the fine earth fraction o si in quartz that start to break and to transform into free radicals k feldspar and plagioclase contain fe when using fe3 as reference point 680 700 nm to standardise the cl spectra the al o al defects of k feldspar exhibit a relative decrease with time this was not the case for plagioclase the cl measurements showed that the investigated apatite contained ree rare earth elements in the crystal structure however none of the other techniques dic sem edx was helpful in detecting any specific weathering features for apatite in the time span of 140 years epidote weathering was evidenced using xrd in a previous investigation and here using dic microscopy morphologic changes several mineral changes could be traced within a very short weathering sequence using the applied techniques these changes include physical e g biotite chemical or crystal structure k feldspar biotite features such an analytical combination is promising therefore for the detection of chemical physical and mineralogical characteristics and changes in very young glacial sediments

observations of wind forced deep ocean currents in the north pacific this study examines the atmospheric response of the deep ocean using 200 instrument years of moored current measurements from across the breadth of the mid latitude north pacific we have found evidence of a seasonal modulation in the ocean eddy kinetic energy beneath the thermocline at several locations north of 35 n this modulation is often in phase with the local atmospheric forcing function at frequencies between 0 1 and 0 01 cpd correlations between the local wind stress curl and the deep currents have been found for a few locations the local forced response is parallel to the potential vorticity gradient f h and consistent in amplitude with a local topographic sverdrup balance nonlocal forcing in the form of flow along isolines of potential vorticity has been estimated and it is comparable to the observed flow at some locations but the modeled flow is not correlated with the observations throughout the mid latitude north pacific the bottom slope tends to enhance the effect this suggests that topography narrows the available bandwidth for forced barotropic rossby waves facilitating a quasi steady topographic sverdrup response over most of the basin however the enhanced effect reduces the magnitude of the ocean s response to wind forcing nonlocally forced sverdrup currents flow along isolines of f h are the dominant component but are only of the order of 1 cm s 1 locally forced sverdrup currents flow across isolines of f h are typically of the order of 0 1 cm s 1 rms and are not commonly measured hence these wind forced variations are a background level signal in the mid latitude eddy kinetic energy in a few isolated areas the bottom slope reduces the effect in these regions the local sverdrup response is amplified and has been observed

refining the eustatic sea level curve since the last glacial maximum using far and intermediate field sites the eustatic component of relative sea level change provides a measure of the amount of ice transferred between the continents and oceans during glacial cycles this has been quantified for the period since the last glacial maximum by correcting observed sea level change for the glacio hydro isostatic contributions using realistic ice distribution and earth models during the last glacial maximum lgm the eustatic sea level was 125 5 m lower than the present day equivalent to a land based ice volume of 4 6 4 9 107 km3 evidence for a non uniform rise in eustatic sea level from the lgm to the end of the deglaciation is examined the initial rate of rise from ca 21 to 17 ka was relatively slow with an average rate of ca 6 m ka 1 followed by an average rate of ca 10 m ka 1 for the next 10 ka significant departures from these average rates may have occurred at the time of the younger dryas and possibly also around 14 ka most of the decay of the large ice sheets was completed by 7 ka but 3 5 m of water has been added to the oceans since that time

bottom pressure variability in the kuroshio extension driven by the atmosphere and ocean instabilities the relative importance of atmospheric forcing on oceanic intraseasonal 7 60 days barotropic variability is investigated in the kuroshio extension region by comparing in situ measurements with two models a wind forced barotropic model and an ocean general circulation model large scale wind stress curl forcing an atmospheric mode becomes successively more influential with decreasing periods at 7 15 day band compared to 15 30 day and 30 60 day bands on the other hand oceanic instabilities an oceanic mode become more important with increasing period at 30 60 day band compared to 15 30 day and 7 15 day bands comparison between the barotropic model and the ocean general circulation model results reveals differences on the broader gyre scale the atmospheric mode exhibits basin mode like spatial patterns with faster phase propagation from east to west whereas the oceanic mode shows eddy like spatial patterns with slower westward propagation the atmospheric mode which has received less attention on the intraseasonal time scale contributes an important fraction to the barotropic variability in the kuroshio extension region

an almost free barotropic mode in the australian antarctic basin 1 the australian antarctic basin aab is known for its high levels of intraseasonal variability sea surface height variability exceeds background values by factors of 2 over thousands of kilometers this paper addresses the hypothesis that this variability is caused by trapping of barotropic energy by the basin geometry analysis of a multi year integration of a shallow water model shows that the variability is dominated by a single large scale statistical mode that is highly coherent over the entire aab the flow associated with this mode is northwestward along the southeast indian ridge southward in the kerguelen abyssal plain and eastward in the southern aab the mode is interpreted as an almost free topographically trapped mode as it is confined by contours of potential vorticity that almost entirely enclose the aab the apex of the wilkes abyssal plain represents the strongest barrier to the modal circulation here velocities are strongest making it a key area for dissipation of kinetic energy through bottom friction and eddy viscosity

quantitative models of sediment generation and provenance state of the art and future developments abstract an overview of quantitative approaches to analysis and modelling of sediment generation and provenance is presented with an emphasis on major framework components as determined by means of petrographic techniques conceptual models of sediment provenance are shown to be consistent with two classes of numerical statistical models i e linear mixing models and compositional linear models these cannot be placed within a common mathematical framework because the former requires that sediment composition is expressed in terms of proportions whereas the latter requires that sediment composition is expressed in terms of log ratios of proportions additivity of proportions a fundamental assumption in linear mixing models cannot be readily expressed in log ratio terms linear mixing models may be used to describe compositional variability in terms of physical and conceptual un mixing models of physical un mixing are appropriate for describing compositional variation within transport invariant subpopulations of grains as a result of varying rates of supply of detritus from multiple sources conceptual un mixing governs the relations among chemical mineralogical and petrographic characteristics of sediments which represent different descriptive levels within a compositional hierarchy compositional linear process models may be used to describe compositional and or textural evolution resulting from selective modifications induced by sediment transport as well as chemical and mechanical weathering current approaches to modelling of surface processes treat the coupled evolution of source areas and sedimentary basins in terms of bulk mass transfer only and do not take into account compositional and textural sediment properties moving from the inverse modelling approach embodied in provenance research to process based forward models of sediment generation which provide detailed predictions of sediment properties meets with considerable albeit not insurmountable problems strategies for developing more advanced parameterizations of sediment properties and for simulating their evolution are proposed and expansion of current data acquisition protocols is discussed in the light of data requirements for such advanced sediment generation models inclusion of sediment generation modules in models of landscape evolution and basin filling will mark a significant step towards full fledged source to sink simulations of earth surface processes

trench normal variation in observed seafloor displacements associated with the 2011 tohoku oki earthquake 1 seafloor geodetic measurements using the gps acoustic technique just above the rupture area of the 2011 tohoku oki earthquake revealed strong trench normal variation in the horizontal crustal displacement associated with the earthquake one set of observations at a site only 50 km away from the trench yielded the most trench ward data ever reported with an accuracy better than 1 m it showed a coseismic displacement of up to 31 m whereas another set of observations 100 km away from the trench showed a 15 m displacement these horizontal data as well as vertical data from pressure gauges and tsunami observations strongly indicate that the seismic slip reached the trench they are also likely to contribute quantitatively to further investigations that reveal the coseismic behavior of the frontal wedge of the overriding plate in the source region along the japan trench

a record high ocean bottom pressure in the south pacific observed by grace in late 2009 to early 2010 the gravity recovery and climate experiment grace satellite pair observed a record increase in ocean bottom pressure obp over a large mid latitude region of the south east pacific its magnitude is substantially larger than other oceanic events in the southern hemisphere found in the entire grace data records 2003 2010 on multi month time scales the obp data help to understand the nature of a similar signal in sea surface height ssh anomaly observed by altimetry the ssh increase is mainly due to mass convergence analysis of the barotropic vorticity equation using scatterometer data atmospheric reanalysis product and grace and altimeter an atmospheric reanalysis product observations suggests that the observed obp ssh signal was primarily caused by wind stress curl associated with a strong and persistent anticyclone in late 2009 in combination with effects of planetary vorticity gradient bottom topography and friction

response of the antarctic circumpolar current to atmospheric variability abstract historical hydrographic profiles combined with recent argo profiles are used to obtain an estimate of the mean geostrophic circulation in the southern ocean thirteen years of altimetric sea level anomaly data are then added to reconstruct the time variable sea level and this new dataset is analyzed to identify and monitor the position of the two main fronts of the antarctic circumpolar current acc during the period 1993 2005 the authors relate their movements to the two main atmospheric climate modes of the southern hemisphere the southern annular mode sam and the el nino southern oscillation enso the study finds that although the fronts are steered by the bathymetry which sets their mean pathway on first order in flat bottom areas the fronts are subject to large meandering because of mesoscale activity and atmospheric forcing while the dominant mode of atmospheric variability in the southern hemisphere sam is relatively symmetric the oceanic response of the fronts is not show

the barotropic response of the subpolar north pacific to stochastic wind forcing in a recent observational study koblinsky et al 1989 attempted to demonstrate that the topographic sverdrup balance can account for mesoscale current fluctuations with periods between 10 and 100 days in the abyssal north pacific however the topographic sverdrup balance proved difficult to verify systematically over the north pacific in this paper the conditions required to obtain the topographic sverdrup balance are investigated through numerical experiments with a stochastically forced barotropic quasi geostrophic numerical model of the subpolar north pacific in the numerical experiments the topographic sverdrup balance emerges from area averages of the terms in the vorticity equation but only for periods longer than about 40 days when the averages are taken over 4 4 region this period increases when averages are taken over progressively smaller regions an examination of vorticity balances at individual points along sections through the model domain indicates that the topographic sverdrup balance is not obtained at individual points even for very long period motions the possibility of verifying topographic sverdrup dynamics with oceanic data is considered it is argued that topographically generated small scales in the velocity field reduce the likelihood that the topographic sverdrup balance can be systematically observed in velocity measurements from individual current meter moorings the results suggest that the vorticity balance is complex and that topographic sverdrup dynamics cannot be expected to provide an adequate explanation for the seasonal modulation of the abyssal eddy kinetic energy that is observed with moored instrumentation in the north pacific

wind forced variability of the deep eastern north pacific observations of seafloor pressure and abyssal currents data from an array of bottom pressure gauges and a string of current meters in the vicinity of 47on 139ow are used to examine the deep ocean variability forced by ocean surface wind stress curl from august 1987 to june 1988 bottom geostrophic currents are computed from the pressure gauge array and these correspond well to the long period directly measured currents at 3000 m the supratidalperiod bottom pressure variations are coherent at 95 confidence with the wind stress curl in period bands of 3 4 days and 15 60 days but removed in distances of 400 and 700 km to the northwest and the southeast respectively a linear two layer hydrodynamic model is used to examine the theoretical forcing produced by random phased surface wind fields for the conditions of the eastern north pacific and the 15 to 60 day period observed response is reproduced credibly to model 3 to 15 day variations more realistic models are required currents are related to surface winds were derived from yearlong current meter records in a cluster of moorings north and east of barbados koblinsky and niiler 1982 showed that significant coherences existed between the 4 to 40 dayperiod east west pulsations of the trade winds r x above barbados and the north south currents v at all depths in the ocean at 15on 54ow the response amplitude of v to r x was depth and period dependent it decreased by a factor of 3 from 150 to 4000 m depths and increased by a factor of 5 from 8 to 40 day periods the interpretation of these data was that the deep ocean forcing was produced by large horizontal scale wind stress curl hereinafter referred to simply as curl due to westward propagating pulses in the trade winds with larger east west than north south scale the amplitude of the deep wind related currents was 1 3 cm s thus deep ocean forcing should be observable in many places where the mesoscale eddy energy is low theoretically wind forced deep ocean motions should depend upon wind stress curl mt iller and frankignoul 1981 using a model of randomly forced linear motions in a stratified infinite flat bottom beta plane ocean computed local coherences and showed that motions across the planetary vorticity gradient should exhibit the strongest coherence with the local wind stress curl niiler and koblinsky 1985 using current meter data demonstrated that such a dynamical link does in fact exist locally at 42on 152ow although at a shorter period than was predicted by milller and frankignoul both the amplitude and the phase of the currents that were forced across the planetary potential vorticity field orf h contours on a 150 km horizontal scale were predicted from the local surface wind stress computed from a similar 150 km scale wind field the 4000 m oscilla

seventeenth century uplift in eastern hokkaido japan shores of eastern hokkaido rose by perhaps i m a few centuries ago the uplifted area extended at least 50km along the southern kuril trench it included the estuaries akkeshi ko and hichirippu on

evidence for wind driven current fluctuations in the western north atlantic two subsurface current meter moorings were deployed for 20 months along 70 w in a low energy portion of the western north atlantic the resulting data were compared with estimates of the wind stress curl in an attempt to seek a relationship between currents below the mixed layer and meteorological forcing at subinertial frequencies currents and temperature tend to be significantly coherent with the curl and are most coherent with the curl at remote locations usually more than 500 km away from the mooring and generally to the east coherences generally decrease with increasing frequency the current response is surface intensified a linear stratified model for stochastically wind forced rossby waves in a flat bottomed ocean is presented as an attempt to rationalize the results the effort was not entirely successful so that it appears that a more realistic model perhaps including bottom topography and mean currents will be needed to rationalize these observations fully

dynamic particle segregation and accumulation processes in time and space revealed in a modern river dominated delta a spatiotemporal record of the kiso river delta central japan abstract the holocene succession of the kiso river delta a sand rich river dominated delta in central japan was analyzed at high temporal and spatial resolution the results demonstrate how the spatiotemporal distribution of sedimentary facies gross sediment accumulation rates and accumulation rates of mud versus sand relate to the geomorphic development of the delta and the post glacial sea level history the centers of peak mud and sand accumulation have migrated seaward in parallel during a regressive stage from 6 5 ka to the present at the rate of 3 9 m y the mud and sand accumulation centers mark the bottom and top respectively of the delta front slope the sediments of the prograding delta show strong sorting and clear upward coarsening because of the steep slope of the delta front such internal topographic control redistributes and separates the coarse and fine fractions of the fluvial input during regression the topographic controlled sedimentary segregation constructs delta front topography in reverse therefore the proportion of sand to mud in the fluvial input controls the stability of the delta front morphology our modeling of the kiso river delta may have implications for prediction of coastal flooding adjacent to deltas in other parts of the world

three forms of variability in argentine basin ocean bottom pressure ocean bottom pressure data are examined from a year long deployment of two bottom pressure recorders separated by 417 km in the argentine basin three forms of variability are found at high frequencies periods shorter than 2 hours the signal appears to be due to gravity wave propagation with the waves preferentially coming from the west at intermediate frequencies periods between 2 hours and 12 days the two records are highly coherent and in phase reflecting large scale coherent fluctuations which are well reproduced in a barotropic ocean model however the dominant mode is at a period of 20 days with a phase lag of about 90 100 degrees between the two records consistent with the a mode of variability previously inferred from satellite altimetry and current meters although the slightly shorter period is consistent with the suggestion that more than one mode contributes to the altimeter observations comparison with altimetry demonstrates that aliasing of higher frequency signals is not a significant source of error and confirms that a previously used altimetry mapping technique reduces the apparent amplitude of the mode the pressure records show a transport change of about 280 sv over one 12 day period and altimetry suggests that regions of higher variability exist the mode is only weakly excited in barotropic models but is strongly excited in a baroclinic model with a realistic eddy field suggesting that it is intrinsically linked to interactions between eddies mean flow and topography

causes of large scale sea level variations in the southern ocean analyses of sea level and a barotropic model 1 we analyze a decade of sea surface height ssh measurements in the southern ocean from the topex poseidon and ers altimeters with a focus on the variability at timescales 2 years among the different processes contributing to large scale ssh variations the barotropic response to the winds dominates poleward of 50 s while thermosteric processes dominate equatorward except for resonant basins for the barotropic modes and regions of intense eddy activity a finite element barotropic model has been developed to analyze the vorticity budget the ssh from the model agrees well with observations the leading barotropic mode which is annular and is confined near antarctica is responsible for most of the barotropic circumpolar transport it is coherent with the zonally integrated eastward wind stress consistent with a free mode response although previously evidenced in bottom pressure data this mode is only partially seen in altimeter data because of ice coverage it nevertheless distinctly appears above the pacific ridges where it expands meridionally up to midlatitudes in the rest of the domain several regions coherent with the local wind stress curl are found these are regions isolated by f h contours mostly deep basins an analysis of the vorticity budget shows that generally topographic sverdrup balance is the leading process for periods 50 days but in some regions resonant basins diffusive and nonstationary terms are important a model experiment shows that transients redistribute energy along f h waveguides contributing to drain resonant regions as was hypothesized in previous works

monthly period oscillations in the pacific north equatorial countercurrent monthly period oscillations in temperature and velocity in the vicinity of the north equatorial countercurrent along 140 w are examined using moored time series data collected during 1988 1989 these oscillations which presumably derive their energy from instability of the large scale shear of the zonal equatorial current system are found to be energetic across a broad band of periods of about 15 50 days along 7 n wavelike motions at these periods propagate westward with a phase speed of about 30 40 cm s 1 and a zonal wavelength of 750 1150 km the oscillations are approximately in geostrophic balance with the thermal field with the velocity vector rotating anticyclonically around westward propagating high sea level centers zonal volume transport variations associated with these waves between 5 and 9 n at 20 180 m depth have a standard deviation of about 4 1 sv with peak to peak changes in some instances approaching 20 sv maximum temperature variance along 140 w occurs between 5 and 7 n at 100 150 m depth in a region of strong mean vertical and meridional temperature gradient associated with a thermocline sloping upward to the north at the surface maximum temperature variability occurs from 2 to 5 n in the vicinity of the strong sea surface temperature front north of the equator analysis of the upper ocean temperature balance at 7 n 140 w reveals that meridional advection is important both in the surface layer and in the thermocline vertical advection estimated using vertical velocity calculated from a simplified linear vorticity balance is also important in the thermocline where it contributes a variance comparable to that of meridional advection zonal advection is likely to be significant in the upper 80 m below which it is probably of secondary importance compared to meridional and vertical advection one consequence of advection in the temperature balance is that variance is shifted toward lower frequencies in temperature vis a vis velocity spectra this red shift may account for the apparent difference between periods for instability waves inferred from near equatorial meridional velocity spectra and slightly longer periods reported for oscillations of the sea surface temperature front north of the equator based on satellite imagery

late quaternary uplift rate inferred from marine terraces muroto peninsula southwest japan forearc deformation in an oblique subduction zone abstract tectonic uplift rates across the muroto peninsula in the southwest japan forearc the overriding plate in the southwest japan oblique subduction zone were estimated by mapping the elevations of the inner edges of marine terrace surfaces the uplift rates inferred from marine terraces m1 and m2 which were correlated by tephrochronology with marine isotope stages mis 5e and 5c respectively include some vertical offset by local faults but generally decrease northwestward from 1 2 1 6 m ky 1 on cape muroto to 0 3 0 7 m ky 1 in the kochi plain the vertical deformation of the muroto peninsula since mis 5e and 5c was interpreted as a combination of regional uplift and folding related to the arc normal offshore muroto misaki fault a regional uplift rate of 0 46 m ky 1 was estimated from terraces on the muroto peninsula and the residual deformation of these terraces was attributed to fault related folding a mass balance calculation yielded a shortening rate of 0 71 0 77 m ky 1 for the muroto peninsula with the muroto misaki fault accounting for 0 60 0 71 m ky 1 but these rates may be overestimated by as much as 10 given variations of several meters in the elevation difference between the buried shoreline angles and terrace inner edges in the study area a thrust fault model with flat 5 10 dip and ramp 60 dip components is proposed to explain the shortening rate and uplift rate of the muroto misaki fault since mis 5e bedrock deformation also indicates that the northern extension of this fault corresponds to the older muroto flexure