erosional control on the geometry and kinematics of thrust belt development in the central andes long term erosion rates in the central andes may have influenced not only mean elevation and relief but also the regional geometry and kinematic history of the orogenic belt a drastic along strike erosional gradient exists in the modern central andes from a high erosion region directly north of the 17 5 s bend in the andes to a low erosion region south of the bend this gradient has existed since 10 15 ma based on fission track analyses of middle miocene to holocene denudation and qualitative evaluations of the preservation potential of middle late tertiary volcanic edifices and synorogenic sediment global positioning system velocity data indicate conflicting patterns of active surface shortening north and south of the 17 5 s bend whereas present day shortening in the thrust belt north of the bend is distributed over much of the width of the belt south of the bend it is concentrated near the eastern frontal margin structural data suggest a similar kinematic situation during late miocene to holocene shortening an out of sequence chronology of thrusting in the narrow 200 km wide thrust belt to the north versus a forward breaking sequence of thrusting in the relatively wide 350 km wide thrust belt to the south the long term internal deformation and limited width of the thrust belt north of the bend are attributed to prolonged subcritical thrust wedge conditions induced by rapid erosion rates since 10 15 ma such conditions inhibit thrust front advance and favor distributed deformation within the thrust belt interior in the thrust belt south of the bend a progressive eastward migration of thrusting is interpreted to be the result of long term critical thrust wedge conditions promoted by extremely low rates of denudation since middle miocene time

high resolution sar interferometry estimation of local frequencies in the context of alpine glaciers synthetic aperture radar sar interferometric data offer the opportunity to measure temperate glacier surface topography and displacement the increase of the resolution provided by the most recent sar systems has some critical implications for instance a reliable estimate of the phase gradient can only be achieved by using interferogram local frequencies in this paper an original two step method for estimating local frequencies is proposed the 2 d phase signal is considered to have two deterministic components corresponding to low resolution lr fringes and high resolution hr patterns due to the local microrelief respectively the first step of the proposed algorithm consists in the lr phase flattening in the second step the local hr frequencies are estimated from the phase 2 d autocorrelation function computed on adaptive neighborhoods this neighborhood is the set of connected pixels belonging to the same hr spatial feature and respecting the ldquolocal stationarityrdquo hypothesis results with both simulated terrasar x interferograms and real airborne e sar images are presented to illustrate the potential of the proposed method

propagation and mechanism of decadal upper ocean variability in the north pacific n n two types of anomaly pathways associated with decadal thermocline variability in the north pacific ocean are identified on constant density surfaces isopycnals one westward and the other southwestward around the subtropical gyre a theory based on two baroclinic planetary wave modes in the thermocline is proposed to account for the observed variability pattern the variability along the westward wave path is ascribed to the non doppler shift ist mode and seems to be forced mainly by wind stress forcing the anomaly along the southwestward subduction path is associated with the advective nature of the 2nd mode and could be excited mainly by surface buoyancy anomalies this study may provide a dynamically unified three dimensional picture of decadal thermocline variability in the north pacific ocean

combining airborne photographs and spaceborne sar data to monitor temperate glaciers potentials and limits monitoring temperate glacier activity has become more and more necessary for economical and security reasons and as an indicator of the local effects of global climate change remote sensing data provide useful information on such complex geophysical objects but they require specific processing techniques to cope with the difficult context of moving and changing features in high relief areas this paper presents the first results of a project involving four laboratories developing and combining specific methods to extract information from optical and synthetic aperture radar sar data two different information sources are processed namely 1 airborne photography and 2 spaceborne c band sar interferometry the difficulties and limitations of their processing in the context of alpine glaciers are discussed and illustrated on two glaciers located in the mont blanc area the results obtained by aerial triangulation techniques provide digital terrain models with an accuracy that is better than 30 cm which is compatible with the computation of volume balance and useful for precise georeferencing and slope measurement updating the results obtained by sar differential interferometry using european remote sensing satellite images show that it is possible to measure temperate glacier surface velocity fields from october to april in one day interferograms with approximately 20 m ground sampling this allows to derive ice surface strain rate fields required to model the glacier flow these different measurements are complementary to results obtained during the summer from satellite optical data and ground measurements that are available only in few accessible points

composition changes in an ash flow cooling unit during k metasomatism west central arizona a variably altered rhyolitic ash flow cooling unit in west central arizona was sampled and analyzed to gain a better understanding of compositional changes that took place during tertiary k metasomatism mn cu zn and other metals of economic importance were removed from the k metasomatized rocks during alteration making them a likely source for these metals in vein and stratiform mn deposits and base metal ores related to detachment faults in western arizona using a single cooling unit to understand the compositional changes during k metasomatism reduces the primary chemical variability inherent in the sampling of multiple units a problem with most previous studies the least altered samples group 1 experienced a moderate degree of k metasomatism having k 2 o na 2 o ratios of 3 1 to 5 5 compared to likely igneous values of 2 the most altered samples group 2 were severely k metasomatized with k 2 o na 2 o ratios of 17 9 to 29 5 k 2 o p 2 o 5 and ba increased in concentration substantially during k metasomatism and mno na 2 o cu zn sr mo and cs decreased all immobile elements decreased in concentration by approximately 9 percent which is attributed to a dilution effect caused by net mass gain in the group 2 rocks principally as k 2 o and sio 2 mineralogical zoning in small late veins seen in thin section is quartz or k feldspar or calcite from vein wall to center the strong covariance in cao and loss on ignition l o i with observed calcite in thin section and the lack of correlation of cao and l o i with other components indicates that their variability is unrelated to k metasomatism calculations indicate that the loss of mn cu zn and other metals from k metasomatized volcanics is easily large enough to account for middle tertiary mn and detachment related cu and zn ore deposits in west central arizona

insar elevation bias caused by penetration into uniform volumes natural media like cold land ice vegetation and dry sand are subject to a substantial penetration at microwave frequencies for such media the synthetic aperture radar sar phase center is located below the surface and consequently the surface elevation determined with sar interferometry insar is biased downward for infinitely deep uniform volumes the elevation bias is often equated with the penetration depth but in this paper it is shown that the two quantities generally differ the interferometric bias is approximately equal to the two way power penetration depth if the latter is small compared to the ambiguity height but for increasing penetration depth the bias approaches one quarter of the ambiguity height consequently no phase wrapping results even if the penetration depth exceeds the ambiguity height the ratio of the insar elevation bias to the ambiguity height depends only on the ratio of the penetration depth to the ambiguity height and the bias can be expressed in terms of the insar coherence magnitude which makes it possible to correct the insar surface elevation for the bias the volume depth can be considered infinite if it exceeds the penetration depth by a factor of two to five and if the surface scattering from the top and the bottom of the volume is negligible

intracontinental rift related deposits a review of key models abstract mineral systems associated with extensional fault systems in continental environments and not related to magmatic activity involve various deposit models that can be grouped into a single system which would plausibly explain the source and chemical composition of fluids the formation depth the source of heat and the structural history within a common geologic setting mineral deposits related to this tectonic setting are those described within the detachment related model including massive replacements stockworks and veins of cu and fe oxides with or without au polymetallic sulfide veins barite and or fluorite veins and stratabound and vein mn deposits this paper reviews the abovementioned deposits as well as others related to this tectonic setting such as se rich polymetallic deposits almaden type hg deposits u ni co as ag polymetallic deposits with subordinated bi cu pb zn five element deposits simple polymetallic pb ag zn deposits and the members of the iocg clan including the au ag detachment related deposits involved in the cu fe au model deposits all these mineral deposits are the result of fluid motion unrelated to magmatism in areas of thermal anomalies these fluids collect certain elements producing a district mineralogical specialization with inhomogeneities in the distribution of mineralization types along the region affected by rifting fluid homogenization temperatures and salinities range between 60 and 430 c and 0 and 27 equivalent wt nacl respectively the o s and d isotope composition is consistent with basinal poral fluids derived from meteoric waters under different p t conditions in an active faults environment pb isotopes suggest that pb derives from a mixture of rocks with a long period of residence in the upper crust and rocks deformed along repeated orogenic cycles with a contribution of pb from the lower crust and even the mantle fluid flow along fault planes leads to different types of hydrothermal alterations depending on p t conditions particularly propylitization and low temperature potassium metasomatism all such deposits can be found in two different geotectonic environments of metallogenic interest involving extensional faults associated with detachment zones in depth i e 1 continental extension in a back arc environment and 2 extension with rift development and generation of oceanic crust in a passive continental margin although the economic importance of this group of deposits is mainly related to industrial minerals non magmatic iocg deposits could significantly augment the economic potential of this setting the rift setting itself without relation to detachments is favorable for concentrating metals in stratabound deposits such as sedex ores additionally the development of deposits directly related to magmatic activity contributes to the economic interest of this environment

simulation of heat storages and associated heat budgets in the pacific ocean 2 interdecadal timescale we use a primitive equation isopycnal model of the pacific ocean to simulate and diagnose the anomalous heat balance on interdecadal timescales associated with heat storage changes observed from 1970 1988 in the expendable bathythermograph xbt data set given the smallness of the interdecadal signals compared to the el nino southern oscillation enso signal the agreement between model and observations is remarkably good the total anomalous heat balance is made up of two parts the diabatic part from the model temperature equation and the adiabatic part from the model mass conservation equation due to thermocline heave we therefore describe our analysis of both the total and diabatic anomalous heat balances in four areas of the tropical and subtropical north pacific ocean in the upper 400 m the interdecadal total diabatic plus adiabatic heat balance in the north pacific ocean is characterized by a complicated interplay of different physical processes especially revealed in basin scale averages of the heat budget components that have comparable amounts of variance in smaller subregions simpler balances hold for example in the western equatorial pacific area 1 the total heat content tendency term is nearly zero so that a simple balance exists between surface heat flux vertical heat transport and horizontal mixing in the western subtropical pacific the total heat content tendency balances the three dimensional divergence of the heat flux we speculate that this complexity is indicative of multiple physical mechanisms involved in the generation of north pacific interdecadal variability the diabatic heat balance north of 24 n a region of special interest to the world ocean circulation experiment woce can be simplified to a balance between the tendency term surface heat flux and meridional advection the last term dominated by anomalous advection of mean temperature gradients for the western equatorial region the diabatic heat content tendency is nearly zero and the steady balance involves simply horizontal advection and the surface heat flux which at these latitudes has a damping role in the model an important finding of this study is the identification of two interdecadal timescales roughly 10 and 20 years both similar to those reported by other investigators in recent years tourre et al 1998 latif and barnett 1994 robertson 1995 white et al 1997 gu and philander 1997 jacobs et al 1994 the 20 year timescale is only present in diabatic heat budget components while the 10 year timescale is present in both diabatic and adiabatic components the 10 year timescale can also be seen in the surface heat flux time series but it occurs in the ocean adiabatic components which demonstrates the importance of oceanic adjustment through rossby wave dynamics on decadal timescales

patterns of mineral transformations in clay gouge with examples from low angle normal fault rocks in the western usa abstract neoformed minerals in shallow fault rocks are increasingly recognized as key to the behavior of faults in the elasto frictional regime but neither the conditions nor the processes which wall rock is transformed into clay minerals are well understood yet understanding of these mineral transformations is required to predict the mechanical and seismogenic behavior of faults we therefore present a systematic study of clay gouge mineralogy from 30 outcrops of 17 low angle normal faults lanf s in the american cordillera to demonstrate the range and type of clay transformations in natural fault gouges the sampled faults juxtapose a wide and representative range of wall rock types including sedimentary metamorphic and igneous rocks under shallow crustal conditions clay mineral transformations were observed in all but one of 28 faults one fault contains only mechanically derived clay rich gouge which formed entirely by cataclasis clay mineral transformations observed in gouges show four general patterns 1 growth of authigenic 1m d illite either by transformation of fragmental 2m 1 illite or muscovite or growth after the dissolution of k feldspar illitization of fragmental illite smectite is observed in lanf gouges but is less common than reported from faults with sedimentary wall rocks 2 retrograde diagenesis of an early mechanically derived chlorite rich gouge to authigenic chlorite smectite and saponite mg rich tri octahedral smectite 3 reaction of mechanically derived chlorite rich gouges with mg rich fluids at low temperatures 50 150 c to produce localized lenses of one of two assemblages sepiolite saponite talc lizardite or palygorskite chlorite quartz and 4 growth of authigenic di octahedral smectite from alteration of acidic volcanic wall rocks these transformation groups are consistent with patterns observed in fault rocks elsewhere the main controls for the type of neoformed clay in gouge appear to be wall rock chemistry and fluid chemistry and temperatures in the range of 60 180 c

a numerical investigation of the subduction process in response to an abrupt intensification of the westerlies abstract a three dimensional ocean general circulation model forced by idealized zonal winds is used to investigate the effect of an abrupt intensification of westerly winds on the subduction process four experiments are carried out 1 a control experiment with standard wind stress forcing 2 an intensified winds experiment with wind stress that is larger in the region of the westerlies than the control 3 an increased surface cooling experiment and 4 an experiment with both intensified wind stress and surface cooling experiments 2 through 4 which contain surface anomalous forcing are run from the steady state obtained in experiment 1 the control experiment the results obtained for each of these runs are compared to the control experiment a subarctic tracer injection experiment is also carried out to verify the differences in the subduction process of each of these experiments in the wind stress intensified experiment an examination of the subsurface temperature field shows that negative t

cathodoluminescence record of k metasomatism in ash flow tuffs grain scale mechanisms and large scale geochemical implications near surface low temperature k metasomatism of rhyolitic to dacitic ash flow tuffs is a volumetrically and petrologically significant feature of the western united states and may be a primary alteration path in arid lands cathodoluminescence cl petrography of k metasomatized ash flow tuffs quickly yields information about the mineralogical changes and reaction mechanisms that take place during alteration for large sample suites and links these properties to geochemical changes tertiary volcanic rocks from creede colorado socorro new mexico and the harcuvar mountains arizona were altered in different geologic settings yet have very similar cl textures and chemistry original igneous feldspars were replaced by adularia primarily by dissolution and crystallization that occurred preferentially along preexisting fractures surfaces compositional zoning features and cleavages fluid flow was primarily along grain boundaries but was in some cases inhomogeneous at the thin section scale

sr isotopic evidence for late neoproterozoic rifting in the adelaide geosyncline at 586 ma implications for a cu ore forming fluid flux abstract analyses of shales and basalts from all stratigraphic levels below the wonoka formation in the neoproterozoic adelaide geosyncline combine to define a 586 30 ma rb sr isochron with an initial 87sr 86sr value of 0 7180 the sr isotopic composition of most carbonate units deposited in this basin before this time are also altered and have sr isotopic compositions that fall between their primary contemporary seawater values and those of the clastic basin fill by contrast the neoproterozoic carbonates from strata including and younger than the late vendian wonoka formation conform to internationally correlated chemostratigraphic variations for both 87sr 86sr and 13c these data together with s and sr isotopic evidence from barite veins which cut late marinoan shales are interpreted to indicate that the adelaidean succession experienced a phase of intrabasinal fluid flow the fluid had an 87sr 86sr value of 0 7180 when convective circulation was terminated at 586 ma this timing is synchronous with down cutting of basin fill to form canyons beneath the wonoka formation and also coincides with the production of rift affiliated alkaline lavas to the east of the curnamona craton in western nsw the interpreted changed fluid flux regime together with the other geological features listed may indicate the onset of a new phase of extension and rifting of east gondwana s eastern margin at 586 30 ma contributing to a growing body of evidence that suggests that the main phase of proto pacific opening may have been vendian rather than sturtian in age the proposed basinal fluid flow event is of economic importance as it mobilised cu and other base metals and may have carried them to depositional sites in the thin platformal western marginal succession of the basin on the stuart shelf

hematite and mn oxide u th he dates from the buckskin rawhide detachment system western arizona gaining insights into hematite u th he systematics

influence of extratropical thermal and wind forcings on equatorial thermocline in an ocean gcm the equatorial thermocline variability in the pacific in response to the extratropical thermal and wind forcings is investigated with an ocean general circulation model modular ocean model version 3 mom3 sensitivity experiments show that the extratropical wind forcing and thermal forcing contribute equally to the equatorial variability the wind induced response is attributed to the off equatorial wind within 30 8 of the equator the thermal induced response can be traced to higher latitudes the thermal forcing affects the equator mainly through the equatorward transport of the perturbation temperature by mean subduction flow the wind forcing affects the equator by changing the strength of meridional overturning circulations it is also found that the southern hemisphere contributes more to the equatorial variability than the northern hemisphere under both external forcings

silver lead zinc veins and crustal hydrology during eocene extension southeastern british columbia canada abstract the kokanee range southeastern british columbia canada contains more than 370 ag pb zn vein and replacement deposits hosted by the middle jurassic nelson batholith and surrounding cambrian to triassic metasedimentary rocks all deposits are in the hanging wall of the slocan lake fault an east dipping low angle normal fault that reaches the moho and along which the valhalla metamorphic core complex has been unroofed during the eocene fluid inclusions in sphalerite quartz or siderite indicate a temperature and pressure of trapping of approximately 300 c and 0 17 gpa the fluid inclusions display a large range of salinities from 0 to 18 wt nacl eq assuming lithostatic pressure at the time of mineralization the depth of mineralization was 6 3 km 34ssulfide values display a 20 range and a regional zonation that correlates with the distribution of sulfur isotopic compositions of host rocks in contrast gd13csiderite values are homogeneous 7 1 0 5 over an area of 1200 km2 it is concluded that s was derived from local country rocks whereas c was derived from mantle co2 degassing the 18osiderite and 18orock values display regional zonations revealing fluid flow paths of a large ancient hydrothermal system three different fluids are identified from salinity 18o and d values 1 1 a high salinity deep seated and isotopically crust equilibrated fluid 2 2 a low salinity upper crustal fluid of evolved meteoric origin 3 3 meteoric water mixing between thermally similar fluids having different salinities is proposed to have been the dominant mineralizing process regional isotopic zonations are controlled by the slocan lake fault which channelled deep seated hydrothermal fluids and mantle co2 to higher crustal levels where mixing occurred with upper crustal fluids that leached local sulfur meteoric water invaded the fracture network in the waning stages of the hydrothermal system

global ocean response to orbital forcing in the holocene 1 global upper ocean evolution in the holocene is studied in two coupled ocean atmosphere models under orbital forcing conditions at 3 6 8 and 11 ka the annual mean sea surface temperature sst changes in the early to mid holocene are found to be forced mainly by the annual mean insolation forcing with an overall symmetric response of colder equator 1 c in the arctic this sst change is consistent with a synthesis of mid holocene paleo sst records in contrast the temperature response in the thermocline is dominated by an antisymmetric pattern with a cooling warming in the northern southern hemisphere midlatitudes the thermocline response is determined predominantly by surface water subduction and ultimately the insolation forcing in local late winter

cordierite formation during the experimental reaction of plagioclase with mg rich aqueous solutions the reaction between plagioclase labradorite and oligoclase and mg rich aqueous solutions was studied experimentally at hydrothermal conditions 600 700 c 2 kbar during the experiments plagioclase grains were readily converted to cordierite and quartz within 4 days the cordierite crystals had well developed polyhedral shapes but showed skeletal internal morphologies suggesting that the initial growth occurred fast under high driving force conditions in pure mgcl2 solutions 0 5 5 m plagioclase dissolution and cordierite precipitation were spatially uncoupled indicating that al was to some extent mobile in the fluid cordierite crystals formed at 700 c showed orthorhombic symmetry whereas those formed at 600 c dominantly persisted in the metastable hexagonal form suggesting a strong increase in al si ordering speed between 600 and 700 c the thermodynamic evolution of the fluid solid system ultimately resulted in stabilization of ca rich plagioclase as demonstrated by partial anorthitization of unreacted plagioclase grains cordierite was also observed to form when mg was added to a potentially albitizing na silicate bearing solution in that case cordierite precipitation appeared to be more closely coupled to plagioclase dissolution and secondary alteration of remnant plagioclase grains did not occur most likely due to armoring of the plagioclase by the cordierite overgrowth the fast reaction rates observed in our experimental study have potential implications for mg metasomatism as a rock forming process

radar interferometry and its application to changes in the earth s surface geophysical applications of radar interferometry to measure changes in the earth s surface have exploded in the early 1990s this new geodetic technique calculates the interference pattern caused by the difference in phase between two images acquired by a spaceborne synthetic aperture radar at two distinct times the resulting interferogram is a contour map of the change in distance between the ground and the radar instrument these maps provide an unsurpassed spatial sampling density 100 pixels km 2 a competitive precision 1 cm and a useful observation cadence 1 pass month 1 they record movements in the crust perturbations in the atmosphere dielectric modifications in the soil and relief in the topography they are also sensitive to technical effects such as relative variations in the radar s trajectory or variations in its frequency standard we describe how all these phenomena contribute to an interferogram then a practical summary explains the techniques for calculating and manipulating interferograms from various radar instruments including the four satellites currently in orbit ers 1 ers 2 jers 1 and radarsat the next chapter suggests some guidelines for interpreting an interferogram as a geophysical measurement respecting the limits of the technique assessing its uncertainty recognizing artifacts and discriminating different types of signal we then review the geophysical applications published to date most of which study deformation related to earthquakes volcanoes and glaciers using ers 1 data we also show examples of monitoring natural hazards and environmental alterations related to landslides subsidence and agriculture in addition we consider subtler geophysical signals such as postseismic relaxation tidal loading of coastal areas and interseismic strain accumulation we conclude with our perspectives on the future of radar interferometry the objective of the review is for the reader to develop the physical understanding necessary to calculate an interferogram and the geophysical intuition necessary to interpret it

k metasomatism and detachment related mineralization harcuvar mountains arizona the bullard detachment fault a regional low angle normal fault exposed in the harcuvar mountains of west central arizona separates lower plate mylonitic rocks and chloritic breccia from upper plate volcanic and sedimentary rocks areally extensive k metasomatism has converted upper plate mafic flows and felsic ash flow tuffs into rocks with 8 to 12 wt k 2 o 2 o and a simple k feldspar hematite quartz mineralogy the secondary k feldspar is very pure or 95 to 99 5 monoclinic and structurally similar to orthoclase differences in 18 o values between secondary k feldspar replacing sanidine phenocrysts 9 to 11 and k feldspar replacing groundmass 11 to 14 in the tuffs imply differential o exchange with migrating fluids whole rock 18 o values for tuffs 10 to 14 and mafic flows 6 to 9 do not therefore represent primary igneous values the rocks apparently became k metasomatized and 18 o enriched while interacting with low to moderate temperature neutral to alkaline oxidizing brines that accumulated in an extensional basin above the detachment fault cu au ag mineralization is concentrated in faults and fissures in metasomatized mafic flows above the detachment fault fluid inclusion studies show that mineralizing fluids had minimum temperatures of 290 to 330 c along the detachment fault 240 to 290 c in mafic flows above the detachment fault and 100 to 130 c in barite calcite mn oxide veins farther from the detachment fault the predominant mineralizing fluids near the detachment fault and in the mafic flows were saline brines with 13 to 17 equivalent wt naci more dilute brines with 6 to 12 equivalent wt naci formed the barite calcite mn oxide veins inferred 18 o values of the mineralizing fluids range from 3 for high temperature quartz sulfide veins to 5 for lower temperature barite calcite mn oxide veins the high salinities oxygen isotope compositions and geologic setting indicate that the mineralizing fluids were basinal brines the mineralizing fluids apparently evolved from early deep level reducing basin brines to a later stage marked by the influx of higher level oxidizing basin brines relatively minor amounts of less evolved lower 18 o meteoric water entered the system during the very late stages of mineralization paragenetic relations and geochemical and isotopic data indicate that mineralization was superimposed on previously k metasomatized rocks mineralization and k metasomatism may be indirectly linked however because both occurred during detachment faulting and both involved basinal brines specifically k metasomatism of upper plate units liberated elements such as cu pb zn mn sr and na that were incorporated into the mineralizing basin brines multiple fluid regimes during detachment faulting are indicated because basin brine dominated mineralization overprinted lower plate mylonitic rocks and breccia that had probably previously equilibrated with igneous or metamorphic fluids at deeper levels of the detachment system

estimating volume change of mountain glaciers using srtm and map based topographic data this paper describes a method for estimating the volume change of mountain glaciers using the shuttle radar topography mission srtm c band data 2000 and a digital elevation model dem generated from topographic maps this approach was developed with srtm data and topographic maps of 1 25 000 scale 1977 from the akshiirak glaciers tien shan central asia the dem for 1977 was generated using 10 m contour lines from 18 map sheets covering the akshiirak massif and surrounding area the nominal vertical accuracy of the maps is 3 3 m the standard deviation of the differences between the map derived dem and the srtm data on glacier free areas of less than 25deg is 6 3 m a single localized region in the western periphery of the study area with systematic error in the srtm data from 20 to 12 m on a 30 km spatial scale was found and excluded from the error analysis assuming a 10 m map error on the upper snow covered glacier areas the estimated root mean square error of the glacier surface change is 8 2 m from 1977 to 1999 the average glacier surface thinning is 15 1 m and the estimated volume loss is 6 15 km3 the rate of the akshiirak glacier volume loss has increased by 2 7 times compared with historical data from 1943 to 1977 the srtm data show an opportunity for quantifying climatic and dynamic surface elevation changes in mountain glaciers ice cloud and land elevation satellite icesat laser altimetry and srtm data could also be used for the estimation of short term surface changes of mountain glaciers

validation of alpine glacier velocity measurements using ers tandem mission sar data five ascending and four descending ers 1 2 tandem mode synthetic aperture radar sar interferometry insar data pairs with useful scene coherence are used to measure the surface flow field of an alpine glacier in the canadian rocky mountains the topographic component of the interferogram phase is calculated by using a digital elevation model dem of the terrain and precise orbit data to reconstruct the ers insar imaging geometry the dem is derived from the canada centre for remote sensing ccrs convair 580 airborne sar interferometer as dual line of sight los measurements are not sufficient to completely resolve the three dimensional 3d surface flow field several different assumptions for determining the missing variables are considered and the 3d surface flow field is estimated by using single and dual los measurements the insar results agree with historic and coincident displacement measurements made using traditional point surveying techniques

measurement of glacier geophysical properties from insar wrapped phase a method is presented for calculating longitudinal glacier strain rates directly from the wrapped phase of an interferometric synthetic aperture radar insar interferogram assuming the ice flow path is known this technique enables strain rates to be calculated for scenes lacking any velocity control points or areas within a scene where the phase is not continuously unwrappable from a velocity control point the contributions to the error in the estimate of the strain rate are evaluated and recommendations for appropriate sar and insar parameters are presented an example using radarsat 1 insar data of an east antarctic ice stream demonstrates the technique for calculating longitudinal strain rate profiles and estimating tensile strength of ice 186 215 kpa from locations of crevasse initiation the strain rate error was found to be 17 corresponding to a tensile strength of ice error of 5 3

surface ocean density gradients during the last glacial maximum we have compiled published planktonic foraminiferal oxygen isotope values from the tropical to subtropical atlantic and pacific for the late holocene and last glacial maximum lgm we interpret the spatial distribution of 18o values in terms of meridional density gradients in the lgm surface ocean and discuss implications on tropical ocean thermocline structure in both oceans glacial 18o values display a pattern of interhemispheric asymmetry evidenced by increasingly higher glacial 18o values toward northern latitudes the 18o derived density estimates suggest that the northern subtropical surface ocean density was higher during the lgm than today which has significant implications on lgm thermocline ventilation in the atlantic steeper density gradients in the northern subtropics during the lgm are consistent with a more compressed subtropical gyre and thermocline water formation farther south than today in the pacific the steeper density gradients suggest a significant reduction in freshwater fluxes to the northern tropical and subtropical regions which raises the possibility of a more significant component of northern hemisphere source waters to the tropical pacific thermocline these predictions could be tested with numerical ocean models that assess the structure of the tropical thermocline in the glacial ocean

linear response of a ventilated thermocline to periodic wind forcing abstractthis article presents a solution for the linear response of a 2 layer ventilated thermocline to large scale periodic wind forcing with a fixed outcrop latitude at the eastern boundary a rossby wave whose vertical structure is similar to the first baroclinic mode is generated and propagates westward in the shadow zone meanwhile the wave is unstable and amplified westward in the southern region in the ventilated zone in addition to the first mode rossby wave generated at the eastern boundary two waves with second mode like vertical structures are generated one wave is generated directly by the wind over the outcrop this wave has a zero zonal wavenumber and southwestward group velocity such that the eastern edge of the wave migrates westward as it propagates southward the other wave is generated by interaction between the westward propagating first mode rossby wave and the outcrop the zonal wavenumber is the same as that of the first mode at the outcrop and the phase of the wave propa

implications of low temperature cooling history on a transect across the colorado plateau basin and range boundary west central arizona fission track ages of apatite and zircon from metamorphic plutonic and sedimentary rocks along a 80 km transect across the colorado plateau basin and range boundary in west central arizona show differences in the low temperature cooling histories between the provinces the transect extends from cypress mountain in the colorado plateau transition zone to the eastern buckskin mountains in the basin and range along the northeast margin of the basin and range province metamorphic rocks exposed in the footwall of a major detachment fault system yield zircon and apatite fission track ages of 16 10 ma these ages are similar to k ar fusion ages of biotite and age minima of k feldspar on 40ar 39ar age spectra and collectively indicate rapid cooling one k feldspar age spectrum has an age maximum of about 22 8 ma an age minimum of 11 8 ma and a spectrum whose shape is suggestive of reheating possibly in middle miocene time the heating event was probably related to hydrothermal activity during emplacement of cu and mn deposits in and above the detachment fault zone effects of this heating are only locally detected in rocks above the detachment fault in the poachie range fission track ages of apatite and zircon are 60 50 and 80 70 ma respectively the disparity between the apatite and zircon ages indicates that the rocks cooled slowly in late cretaceous and early tertiary time probably due to gradual uplift and erosion total uplift and denudation in the area of the poachie range since cretaceous time is 6 km or more to the northeast of the range fission track ages of apatite and zircon increase and diverge indicating that apparent uplift decreased in that direction the apatite ages from the poachie range are concordant with early tertiary hornblende ages determined in other studies of lower plate rocks near the southwest end of the transect the ages represent cooling of crystalline rocks after cretaceous regional metamorphism and magmatism near bagdad 20 km northeast of the poachie range 2 km or less of erosion has occurred since intrusion of high level plutons and dikes and caldera formation in late cretaceous time remnants of an erosion surface that developed in middle tertiary time are preserved in the transition zone volcanic and sedimentary rocks at least as old as early miocene were deposited on the erosion surface and filled valleys cut into it dissection of these deposits began about 8 ma we interpret these data combined with those from other studies to indicate that in cretaceous time southward thrusting and later extensive magmatism in the middle crust led to thickening and heating of the crust the cretaceous igneous rocks at bagdad are high level manifestations of this magmatism uplift and slow cooling occurred in late cretaceous and early tertiary time in late oligocene and early miocene time during northeast southwest extension middle crustal rocks moved southwest put from beneath the southwest margin of the transition zone tectonic denudation rapidly exposed the crust that had been brought up from a depth of 10 km or more and rapidly cooled in the eastern buckskin and harcuvar mountains middle miocene reheating occurred locally in the lower plate along the detachment and in nearby parts of the upper plate

effects of hydrothermal alteration on the magnetization of the oligocene carpenter ridge tuff bachelor caldera san juan mountains colorado intracaldera oligocene carpenter ridge tuff fills the bachelor caldera in the central san juan caldera complex and hosts mineral deposits of the creede mineral district the carpenter ridge tuff and unaltered portions of its intracaldera bachelor mountain member have strong high coercivity reverse magnetizations with average magnetic susceptibility ms and natural remanent magnetization nrm of 6 10 3 volume si and 8 a m respectively oxide phenocrysts in these rocks are titanomagnetite and ilmenite however magnetization appears to be controlled by microcrystic titanomaghemite based on thermal demagnetization unblocking temperatures and curie temperatures between 580 c and 620 c much of the intracaldera tuff was affected by potassic metasomatism a type of hydrothermal alteration characterized by addition of k and loss of ca and na between 27 3 ma and 25 1 ma potassic metasomatism resulted in the replacement of original feldspars by potassium feldspar and quartz oxidation of the original oxide phenocrysts to hematite and rutile and consequent suppression of ms and nrm by a factor of 5 also present however are metasomatized rocks that have high magnetizations even though their original oxide phenocrysts were destroyed values of ms and nrm are similar to those of outflow tuff such rocks are suspected of containing secondary magnetite on the basis of 1 curie and thermal unblocking temperatures at and below 580 c indicating that magnetization is carried by magnetite but that primary microcrysts of maghemite were destroyed and 2 observation in one sample of magnetite rimming cores of hematite rutile the presence of secondary magnetite in metasomatized rocks requires a local shift to more reducing fluid chemistry although we are unable to determine whether this shift occurred during potassic metasomatism or during later alteration or ore deposition these altered rocks may record a change from a pervasive alteration by alkaline oxidizing fluids to a vein controlled alteration dominated by more reduced fluids in which magnetite was stable

decadal buoyancy forcing in a simple model of the subtropical gyre the decadal response of the ventilated thermocline to surface buoyancy forcing is investigated using simplified mixed layer thermodynamics and two layer planetary geostrophic dynamics the model is forced by a stationary ekman pumping and a fluctuating sea surface density while the associated surface buoyancy flux is diagnosed from the buoyancy budget of ventilated columns the decadal forcing is represented as a slow modulation of the seasonal cycle rather than a slow periodic forcing as in liu and pedlosky it is found that the amplitude and the degree of nonlinearity of the interior response depend on the anomalies of the yearly averaged surface buoyancy flux but that omitting the seasonal cycle leads to an overestimation of the thermocline variability by a factor of 2 at periods longer than 10 years the interior response becomes linear and frequency independent so that in the presence of stochastic buoyancy forcing the spectrum of potential vorticity or interface displacement is white at low frequency and red at high frequency a statistical signature of the buoyancy forcing is the asymmetric shape of the cross covariance function between sea surface density and interface displacement anomalies in lead and lag conditions

subduction of decadal north pacific temperature anomalies observations and dynamics abstract observations of oceanic temperature in the upper 400 m reveal decadal signals that propagate in the thermocline along lines of constant potential vorticity from the ventilation region in the central north pacific to approximately 18 n in the western pacific the propagation path and speed are well described by the geostrophic mean circulation and by a model of the ventilated thermocline the approximate southward speed of the thermal signal of 7 mm s 1 yields a transit time of approximately eight years the thermal anomalies appear to be forced by perturbations of the mixed layer heat budget in the subduction region of the central north pacific east of the date line a warm pulse was generated in the central north pacific by a series of mild winters from 1973 to 1976 and reached 18 n around 1982 after 1978 a succession of colder winters initiated a cold anomaly in the central north pacific that propagated along a similar path and with a similar speed as the warm anomaly then arrived in the west

decadal thermocline variability in the north pacific ocean two pathways around the subtropical gyre yearly in situ temperature anomaly data in the north pacific ocean for 1961 90 have been analyzed along constant density surfaces isopycnals in order to better describe and understand decadal thermocline variability in the region various empirical orthogonal function analyses are performed on isopycnals to depict the dominant three dimensional patterns the major finding is of two preferential pathways associated with decadal temperature variability around the subtropical gyre a subduction pathway with a large signal in the upper thermocline originates from the north pacific central eastern outcrop regions about 408n 1508w and then basically follows the mean gyre circulation southwestward along isopycnals toward the western tropics a subtropical pathway extends from the eastern subtropical tropical and boundary regions and appears to continue predominantly westward across the southern part of the gyre between 158 and 308n and then along the kuroshio path toward the midlatitudes along these two pathways thermal anomalies show coherent phase relationships to one another in the surface layer and in the thermocline around the gyre with their source regions variability centers being out of phase on decadal timescales two examples of each type of anomaly pattern can be illustrated for the periods analyzed in the 1960s a negative temperature anomaly signal propagated predominantly westward across the subtropics followed by a subducted warm anomaly from the outcrop region in the early 1970s that subsequently moved southwestward along isopycnals toward the western tropics a similar pattern was observed in the late 1970s and in the 1980s but with the opposite sign a westward propagating positive temperature anomaly signal along the subtropics in the late 1970s through the 1980s and a subducted cold anomaly in the early 1980s that also made its way southwestward with the expected gyre circulation to the western tropics in the late 1980s it is suggested that the southwestward subduction pathway provides a mechanism that connects surface anomalies in the outcrop region to thermocline variations in the western subtropics and in the tropics and that the westward subtropical pathway presents a possible link of tropical subtropical variability to surface temperature anomalies around the kuroshio and its extension regions which may further force variations in the overlying atmospheric circulation in the midlatitudes the results provide an observational basis for verification of theoretical studies and model simulations

improvement of satellite radar feature tracking for ice velocity derivation by spatial frequency filtering outlet glaciers of ice sheets are the primary means of transporting ice from the interior to the oceans and their flow velocity is one control that determines the mass balance of ice sheets estimates of ice velocities particularly for remote areas are commonly based on satellite remote sensing data as radar based systems emit energy at frequencies high enough to penetrate clouds they can record backscatter signals from surfaces throughout the year radar data which are collected with repeat pass spaceborne platforms are therefore good for extracting ice velocities using interferometry for slow moving ice and the cross correlation techniques for fast moving ice here we present an improvement on the cross correlation technique that enables independent quality checks and enhances the spatial extent of the derived velocity fields filtering of esa european remote sensing satellite scenes based on a butterworth high pass spatial frequency filter focuses the cross correlation technique on smaller movable surface features instead of large fixed features it also allows a nonregional culling based on the signal to noise ratio of the velocities with the effect of increasing the coverage of robust velocity estimates

origin and age of rift related fluorite and manganese deposits from the san rafael massif argentina abstract the san rafael massif is characterized by widespread fluorite and manganese epithermal ore deposits whose origin has been under debate to the present isotopic sm nd and k ar and geochemical trace elements and ree data of fluorite and manganese ore allowed to establish the age and genesis of the deposits and to propose a regional genetic model the fluorite deposits were formed during the upper triassic lower jurassic as a result of the triassic rifting that launched a hydrothermal activity at regional scale the hydrothermal fluids had low t and high fo2 with fluorine probably derived from a mantle source and ree scavenged from the volcanics of the gondwanan choiyoi magmatic cycle upper section the manganese deposits were formed by oxidizing hydrothermal fluids that collected mn from deep sources and also leached ree from the upper section of the choiyoi magmatic cycle during two mineralization episodes one episode was linked to the rift tectonic setting that remained active up to the upper cretaceous and the other was related to an early miocene back arc extensional geodynamic setting both manganese and fluorite deposits were formed in extensional tectonic settings within an epithermal environment near the surface and can be ascribed to the general model of detachment related deposits

glacier motion estimation using sar offset tracking procedures two image to image patch offset techniques for estimating feature motion between satellite synthetic aperture radar sar images are discussed intensity tracking based on patch intensity cross correlation optimization and coherence tracking based on patch coherence optimization are used to estimate the movement of glacier surfaces between two sar images in both slant range and azimuth direction the accuracy and application range of the two methods are examined in the case of the surge of monacobreen in northern svalbard between 1992 and 1996 offset tracking procedures of sar images are an alternative to differential sar interferometry for the estimation of glacier motion when differential sar interferometry is limited by loss of coherence i e in the case of rapid and incoherent flow and of large acquisition time intervals between the two sar images in addition an offset tracking procedure in the azimuth direction may be combined with differential sar interferometry in the slant range direction in order to retrieve a two dimensional displacement map when sar data of only one orbit configuration are available

from jurassic shores to cretaceous plutons geochemical evidence for paleoalteration environments of metavolcanic rocks eastern california volcanic and plutonic rocks exposed in east central california record a long history of metasomatism and or metamorphism within the mesozoic cordilleran continental arc we use whole rock and mineral elemental compositions along with standard and cathodoluminescence petrography to characterize alteration histories of late triassic to middle jurassic metavolcanic rocks in the ritter range white inyo mountains and alabama hills although alkali metasomatism is widespread and pervasive ratios and abundances of ce th tb and ta suggest that mafic protoliths from the white inyo mountains were shoshonitic whereas those from the ritter range were calc alkaline alkali exchange apparently modified the compositions of many metavolcanic rocks much of this metasomatism may have occurred at low temperature t conditions and attended or shortly postdated deposition of the volcanic protoliths high 18 o values for k rich metatuffs from

thermocline forced by annual and decadal surface temperature variation abstract a two layer thermocline model is modified by adding an essentially passive mixed layer above it the surface temperature variation is simulated by a moving outcrop line it is found that in contrast to a surface wind stress a surface temperature variation causes strong variability in the ventilated zone through subducted water while it affects the shadow zone little two types of buoyancy forced solution are found when the outcrop line moves slowly the solutions are nonentrainment solutions for these solutions the surface beat flux is mainly balanced by the horizontal advection in the permanent thermocline the mixed layer never entrains the time mean thermocline is close to the steady thermocline with the time mean outcrop line when the outcrop line moves southward rapidly during the cooling season the solutions become entrainment solutions now deep vertical convection must occur because the horizontal advection in the permanent thermocline is no longer strong enough to balance the s

kinetically limited isotope exchange in a shallow level normal fault mineral mountains utah we have conducted a stable isotope and geochemical study of the corral canyon fault zone a shallow level low angle normal fault on the west flank of the mineral mountains in southwest utah our stable isotope and geochemical data document the infiltration of local meteoric water during brittle deformation and hydrothermal alteration of the shear zone during tertiary basin and range extensional faulting within the fault zone 18o depletion correlates with progressive hydrothermal alteration and cataclasis demonstrating that the processes of fluid infiltration hydrothermal alteration fracturing comminution of grains and 18o exchange took place concurrently interpretation of our data using a model of combined fluid flow and kinetically limited isotope exchange leads us to conclude that the exposed fault zone was infiltrated by isotopically unevolved fluids from the wall rock adjacent to the fault zone and that an important component of fluid flow in this fault was between the wall rock and the fault zone rather than strictly within the fault plane we propose that the rate of isotopic alteration in shallow level fault zones is enhanced by comminution and recrystallization of grains during deformation so that fluids in the wall rock because of the relatively coarser grain size remain relatively unevolved until they infiltrate the fault zone where they rapidly become isotopically evolved due to exchange with cataclasized grains we present a general model for calculating the duration of isotopic alteration in flow systems characterized by kinetically limited isotope exchange calculated exchange durations for the corral canyon fault zone are short on the order of thousands to a few hundreds of thousands of years compared to the likely duration of deformation of millions of years the geologically short duration of isotope exchange leads us to suggest that the fluid flow responsible for the isotopic alteration was episodic of short duration and possibly related to discrete seismic events this result corroborates diverse lines of evidence that support a model of alternating fluid flow and permeability sealing by hydrothermal precipitation within fault zones

global teleconnections of meridional overturning circulation anomalies there is a wide range of evidence from both models and palaeoclimatic data that indicates the possibility of abrupt changes in the oceanic meridional overturning circulation moc however much of our dynamical understanding of the moc comes from steady state models that rely upon the assumption of thermodynamic equilibrium and are therefore only valid on millennial time scales here a dynamical model for the global teleconnections of moc anomalies on annual to multidecadal time scales is developed it is based on a linear theory for the propagation of zonally integrated meridional transport anomalies in a reduced gravity ocean and allows for multiple ocean basins connected by a circumpolar channel to the south the theory demonstrates that the equator acts as a low pass filter to moc anomalies as a consequence moc anomalies on decadal and shorter time scales are confined to the hemispheric basin in which they are generated and have little impact on the remainder of the global ocean the linear theory is compared with the results of a global nonlinear numerical integration which it reproduces to a good approximation

how the harcuvar mountains metamorphic core complex became cool evidence from apatite u th he thermochronometry apatite u th he ahe data from 60 km of exposed footwall in the harcuvar mountains metamorphic core complex arizona reveal a higher precision late stage cooling history than previously reported for this complex and others in the region progressively younger ahe ages recorded with distance along the slip direction show two distinct trends separated by a sharp inflection at structurally shallower levels ages decrease from ca 23 to 15 ma toward the northeast defining an estimated slip rate of 2 6 0 1 0 2 km m y samples from the structurally deepest 35 km of footwall yield concordant ages of ca 15 ma 2 error limits the effects of mineralizing fluids advection of isotherms toward the surface and flexure induced erosion are considered but are unlikely to have influenced the ages therefore it is suggested that the fault slip rate must have increased ca 15 ma to a rate of 30 km m y evidence for an increased slip rate ca 15 ma has also been observed in other metamorphic core complexes nearby and this increase is attributed to the thermal effects of a slab free window on the extending lithosphere

evolution of subduction planetary waves with application to north pacific decadal thermocline variability abstract the evolution of decadal subduction temperature anomalies in the subtropical north pacific is studied using a simple and a complex ocean model it is found that the amplitude of the temperature anomaly decays faster than a passive tracer by about 30 50 the faster decay is caused by the divergence of group velocity of the subduction planetary wave which is contributed to significantly by the divergent sverdrup flow in the subtropical gyre the temperature anomaly also seems to propagate southward slower than the passive tracer or mean ventilation flow this occurs because the mean potential vorticity gradient in the ventilated zone is directed eastward the associated general beta effect produces a northward propagation for the temperature anomaly partially canceling the southward advection by the ventilation flow

buoyancy and wind driven circulation in an extended model of potential vorticity homogenization an analytical model is proposed on the middepth water circulation between the surface wind driven circulation and the deep buoyancy driven circulation the model consists of three and a half layers with the second and third layers being the middepth layers the model includes thermohaline processes by allowing diapycnal flows at interfaces between layers in addition to the potential vorticity homogenization proposed by rhines and young the velocities of diapycnal flow are calculated from the density stratification which can be given solely by a wind driven model as a good approximation the divergence of diapycnal velocity causes a circulation in addition to the wind driven circulation although in pure wind driven theories motion was absent outside the region of homogenized potential vorticity the present model gives significant currents there in particular a prominent eastward flow appears in the third layer along the southern rim of the homogeneous potential vorticity region in the second layer the flow pattern in the present model is consistent with that estimated diagnostically from the climatological density distribution in the north pacific the diagnosed flow field is further supported by the oxygen distribution there

propagation of the subsurface freshening water and its major source in the northwestern pacific previous studies of the exchanges of the subtropical tropical salinity in the north pacific are still not conclusive some studies suggest that surface salinity anomalies formed in the northeastern subtropics can subduct and penetrate to the subsurface of the northwestern pacific whereas others demonstrate that subsurface salinity anomalies in the northwestern pacific cannot be traced back to those of the eastern subtropics this study examined the variability of subsurface salinity in the northwestern pacific with focus on its propagation characteristic and forcing mechanism in its outcrop region it is found that salinity anomalies on 24 5 25 4 kg m 3 isopycnals exhibited a pronounced freshening trend in the northwestern pacific during 2003 2012 this freshening can be traced back to the surface salinity anomalies in the outcrop zone of the northwestern subtropical gyre rather than that of northeastern subtropics the representative transit time from its outcrop region to the eastern luzon strait is about 1 3yr the surface salinity anomalies in the outcrop zone are mainly controlled by air sea freshwater flux change although the contribution of horizontal advection is also important in particular for year to year variation compared to the air sea freshwater flux and horizontal advection the contribution of mixed layer depth to the surface salinity anomalies is smaller and can be neglected in the outcrop zone of the northwestern pacific

variability of the thermocline due to a sudden change in the ekman pumping the thermocline variability caused by a sudden variation of the ekman pumping is studied using a 2 5 layer geostrophic model that represents the ventilated and the shadow zones of a subtropical gyre and baroclinic rossby wave propagation during spinup the propagation of the first baroclinic mode induces a large deepening of the thermocline on a timescale ranging between 2 and 15 yr depending on latitude the propagation is similar throughout the basin and is not influenced by the geostrophic flow save nonlinearly through the variation in layer depth south of the subduction line the adjustment is completed by the second baroclinic mode in the ventilated zone the latter is not very active and there are only smaller by a factor of 5 variations of the thermocline depth primarily linked to a slight imbalance between ekman pumping and vertically averaged meridional advection in the shadow zone the second baroclinic mode plays a more important role since it primarily balances the ekman pumping although the variations of the second layer depth remain smaller than in the ventilated area spindown induces similarly a shoaling of the thermocline but because of nonlinearities lower rossby wave speeds and decreased advection the adjustment is everywhere slower than during spinup

a basinwide estimate of vertical mixing in the upper pycnocline spreading of bomb tritium in the north pacific ocean abstract the vertical diffusivity kv in the upper half kilometer of the north pacific subtropical pycnocline is estimated from observations of the spreading rate of anthropogenic tritium the calculation is based on approximately 300 ocean tritium profiles made since tritium was introduced to the atmosphere via bomb testing in the 1960s the data coverage does not permit detailed mapping of tritium penetration especially in the sparsely sampled western pacific for this reason and to minimize advective effects the spreading rate is averaged within the closed streamlines of the subtropical gyre spanning 5 n to 40 n the result kv 1 5 0 7 10 5 m2 s 1 is consistent with inferences from microstructure and purposefully released tracer measurements in the north atlantic confirming that the spatially averaged rate of mixing in the upper pycnocline is substantially lower than the canonical munk estimate for the lower pycnocline

simple model prediction of horizontal temperature fields in the subtropical subpolar system caused by sudden change in wind stress curl abstract a four level numerical model which is driven by wind stress and surface heat flux is used to study responses of horizontal temperature fields in the subtropical subpolar system to a sudden change in the magnitude of the wind stress curl weakly nonlinear responses to o 1 change in the wind stress curl are examined according to the effects on the ekman pumping convection westward baroclinic wave and advection for this purpose a quasi analytical method that is characteristics associated with effects of both wave propagation and advection is constructed based on a planetary geostrophic model with four level geometry characteristics obtained for the first and second baroclinic modes are used to diagnose steady state and time dependent solutions one feature of time dependent motions predicted by the model is a westward propagation of the first baroclinic mode with a significantly higher speed than the combined speed of the nondispersive first mode baroclinic rossby wave and barotropic ci