a review of glacial geomorphology and chronology in northern spain timing and regional variability during the last glacial cycle abstract in this paper we synthesize the research in glacial geomorphology and geochronology in northern spain with special attention to the evidence of local glacier maximum extent earlier than the global lgm of mis 2 18 21 ka bp more accurate models of glacier evolution have been defined based on limnogeological geochronological and geomorphological data in the pyrenees osl optically stimulated luminescence surface exposure and radiocarbon dating techniques have identified end moraines and fluvial terraces corresponding to mis 6 about 170 ka and even to mis 8 about 260 ka and also established the timing of the last local glacial maxima as prior to global lgm mis 4 ca 50 70 ka during the global lgm a smaller re advance occurred but glaciers reached different extents in the central and the eastern pyrenees in nw iberia radiocarbon and osl techniques point to local glacial maximum prior to ca 26 ka 38 ka and probably synchronous with 45 ka although some bias might have been introduced by the dating procedures this review demonstrates that in both regions the local maximum extent occurred prior to the global lgm the asynchronies between the glacial maxima chronologies in the different mountain ranges of northern spain suggest that local climate factors exert a strong control on mountain glacier dynamics

doppler profiler and radar observations of boundary layer variability during the landfall of tropical storm gabrielle abstract detailed observations of boundary layer structure were acquired on 14 september 2001 prior to and during the landfall of tropical storm gabrielle the mobile integrated profiling system mips and the shared mobile atmospheric research and teaching radar smart r were collocated at the western florida coastline near venice very close to the wind center at landfall prior to landfall the boundary layer was rendered weakly stable by a long period of evaporational cooling and mesoscale downdrafts within extensive stratiform precipitation that started 18 h before landfall the cool air mass was expansive with an area within the 23 c surface isotherm of about 50 000 km2 east northeasterly surface flow transported this cool air off the west coast of florida toward the convergent warm core of the gabrielle and promoted the development of shallow warm and cold fronts that were prominent during the landfall phase airflow properties of the boundary layer around the coastal zone are examined using

emplacement of the cuera and picos de europa imbricate system at the core of the iberian armorican arc cantabrian zone north spain new precisions concerning the timing of arc closure the final stages of the variscan orogeny mostly carboniferous in the western european variscan belt involved the development of the iberian armorican arc which is cored by the cantabrian zone nw iberia the cantabrian zone is the foreland of the western european variscan belt and it is interpreted to record the waning stages of the closure of the rheic ocean the distalmost tectonic units within the cantabrian zone the cuera unit and the picos de europa province were the last tectonic units emplaced at the core of the western european variscan belt orocline together they form an imbricate system and associated wedge top basins that are key to understanding the development of the orocline the emplacement of the cuera unit and the picos de europa province occurred in the latest pennsylvanian between moscovian and gzhelian times new detailed mapping together with stratigraphic sedimentologic and biostratigraphic data analysis of syntectonic successions and structural information constrain the timing and evolution of this imbricate system our analysis indicates that the thrust sheets were emplaced roughly perpendicular to previous tectonic units of the cantabrian variscan foreland fold and thrust belt most probably during the oroclinal bending of the sw european variscan belt that formed the iberian armorican arc the n s directed imbricate system was characterized by a shallow dip of the topographic surface 150 15 km and complex structure of the orogenic wedge are thought to result from the progressive increase in the dip of the basal decollement during bending of the underlying gondwana lithosphere and may reflect the closure of the iberian armorican arc

quaternary environmental evolution in the south carpathians reconstructed from glaciokarst geomorphology and sedimentary archives abstract the carpathian island type glaciokarst has a great potential of preserving signals of past environments archived in cave deposits like speleothems and clastic infills we present here the geomorphology and structural control of several relict alpine caves and the surrounding glaciated marble karst in the f g ra mountains four truncated and partially unroofed caves remained on the ridge top of mu eteica mountain above the glacial cirque while a ponor cave that developed on the cirque bottom could be related to the last glacial period structural measurements and cave morphology showed that the conduits formed at the intersection of foliation planes and tectonic fractures on the ne sw and nw se directions cave development reflects three speleogenetic stages 1 texture and fabric controlled dissolution and distension 2 structurally controlled breakdown and 3 truncation unroofing and cave infilling with sediments slow diffuse dissolution was typical for the ridge top caves whereas m1 cave developed by pressure flow further we report the first u th speleothem ages related to the evolution of alpine caves and island glaciokarst in the south carpathians during the middle and late pleistocene dating results show a minimum estimated age of 560 ka for the ridge top caves and that speleothem deposition met optimal conditions only during warmer periods largely corresponding to interglacials stable carbon isotope values in speleothems range between 9 96 and 4 11 indicating the presence of plant and soil organic activity at the time of deposition in total five speleothem growth phases were distinguished during the last 560 ka we excavated the sediment infill of a ridge top doline down to a 2 m depth radiocarbon dating revealed that it was deposited during the late holocene and preliminary pollen analysis identified a plant assemblage dominated by grasses using the relationships between karst development glaciation and cave sedimentary archives we present a time slice chronology of alpine landscape evolution at 560 ka 400 ka 330 ka the last glacial period 70 12 ka and the late holocene our geomorphological isotopic and geochronological results also support the existing hypothesis that the south carpathians may have experienced at least two glacial phases during the pleistocene glacial erosion rate during the last glacial period and most likely during the penultimate glaciation averages around 0 6 mm yr 1

morphometric analysis of three dimensional networks of karst conduits the main idiosyncrasy of a typical karst system is the presence of a three dimensional network of conduits behaving as drains in the system and being responsible of both the quick response of karst springs to rainfall events and the complex distribution of solutes in the system a morphometric analysis of the three dimensional geometry of conduits provides quantitative measures that can be used in a range of applications these morphometric parameters can be used as descriptors of the underground geomorphology they provide information on speleogenesis processes they can be correlated with karst denudation ratios they can be used to control the simulation of realistic stochastic karst networks of conduits and they can be correlated with hydrogeologic behaviour of the karst system the main purpose of this paper is to define describe and illustrate a range of morphometric indexes and morphometric functions that can be calculated nowadays because the availability of three dimensional topographies provided by speleological work and the availability of the computational and graphical power provided by modern computers some of the morphometric parameters describe the existence of preferential directions of karstification others describe the kartification along the vertical and the possible presence of inception horizons other indexes describe the shape complexity of the karstic network whilst other indexes describe spatial variability of the conduit geometry and other parameters give account of the connectivity of the three dimensional network the morphometric analysis is illustrated with a three dimensional karstic network in southern france

wind profiles in tropical cyclone stratiform rainbands over land abstractobservations of 14 stratiform periods in outer tropical cyclone rainbands are used to evaluate wind structure using a velocity azimuth display vad technique applied to kamx miami weather surveillance radar 1988 doppler wsr 88d data these 14 cases occurred over land in southern florida from tropical storm fay and hurricanes gustav and ike during 2008 profiles show a maximum horizontal wind speed between 1000 and 1500 m in height with occasional evidence of a secondary horizontal wind maximum near 3500 5000 m storm relative wind components are calculated and radial wind profiles show a mean transition from radial inflow at low levels to radial outflow around 2500 3000 m altitude the radial inflow maximum is around 500 m while maximum outflow is more variable these profile characteristics are consistent with previous wind observations in rainbands over land and water changes in wind structure within one 4 h period are examined with changes seen linked to the environmental influence on

a spatio temporal landslide inventory for the nw of spain bapa database abstract a landslide database has been created for the principality of asturias nw spain the bapa base de datos de argayos del principado de asturias principality of asturias landslide database data collection is mainly performed through searching local newspaper archives moreover a bapa app and a bapa website http geol uniovi es bapa have been developed to obtain additional information from citizens and institutions presently the dataset covers the period 1980 2015 recording 2063 individual landslides the use of free cartographic servers such as google maps google street view and iberpix government of spain combined with the spatial descriptions and pictures contained in the press news makes it possible to assess different levels of spatial accuracy in the database 59 of the records show an exact spatial location and 51 of the records provided accurate dates showing the usefulness of press archives as temporal records thus 32 of the landslides show the highest spatial and temporal accuracy levels the database also gathers information about the type and characteristics of the landslides the triggering factors and the damage and costs caused field work was conducted to validate the methodology used in assessing the spatial location temporal occurrence and characteristics of the landslides

numerical study on the development of asymmetric convection and vertical wind shear during tropical cyclone landfall idealized simulations on an f plane of tropical cyclone tc landfall under a quiescent environment in the southern hemisphere are performed to investigate the effects of land sea surface contrast on precipitation in the control simulation with realistic roughness and moisture over land to the south of the tc the simulated vortex moves toward land due to a land induced steering flow the abrupt decrease increase of tangential wind at the surface leads to convergence divergence on the onshore offshore flow side enhanced convergence at the top of the planetary boundary layer is found on both onshore and offshore sides and is caused by advection from the surface and the enhanced offshore radial wind the boundary layer top convergence pattern is consistent with the rainfall distribution vertical wind shear develops during the landfall process associated with the low and upper level asymmetric flows across the model domain the wavenumber 1 like low level asymmetric flow is introduced by an asymmetric geopotential height field that is generated by the large area of frictionally induced convergence on the onshore side and divergence on the offshore side the upper level asymmetric flow is attributed to asymmetric convection and associated diabatic heating after landfall most rainfall is found in the down shear right quadrant which is consistent with previous studies that focused on the effect of environmental shear although the existence of feedback from the vertical wind shear to rainfall remains an open question the relation between maximum rainfall and vertical wind shear is robust especially when the shear magnitude is large after landfall

northern iberian abrupt climate change dynamics during the last glacial cycle a view from lacustrine sediments abstract we present a palaeoclimatic reconstruction of the last glacial cycle in iberia ca 120 000 11 600 cal yrs bp based on multi proxy reconstructions from lake sediments with robust chronologies and with a particular focus on abrupt climate changes the selected lake sequences provide an integrated approach from northern iberia exploring temperature conditions humidity variations and land sea comparisons during the most relevant climate transitions of the last glacial period thus we present evidence that demonstrates i cold but relatively humid conditions during the transition from mis 5 to mis 4 which prevailed until ca 60 000 cal yrs bp in northern iberia ii a general tendency towards greater aridity during mis 4 and mis 3 ca 60 000 to 23 500 cal yrs bp punctuated by abrupt climate changes related to heinrich events he iii a complex highly variable climate during mis 2 23 500 to 14 600 cal yrs bp with the mystery interval mi 18 500 to 14 600 cal yrs bp and not the global last glacial maximum lgm 23 000 to 19 000 cal yrs bp as the coldest and most arid period the last glacial transition starts in synchrony with greenland ice records at 14 600 cal yrs bp but the temperature increase was not so abrupt in the iberian records and the highest humidity was attained during the allerod gi 1a to gi 1c and not during the bolling gi 1e period the younger dryas event gs 1 is discernible in northern iberian lake records as a cold and dry interval although iberian vegetation records present a geographically variable signal for this interval perhaps related to vegetation resilience

asymmetric structures in a simulated landfalling hurricane abstract highly asymmetric structures in a landfalling hurricane can lead to the formation of heavy rains wind gusts and tornados at prefered locations relative to the center of the hurricane in this study the development of asymmetric structures in an explicitly simulated idealized hurricane during landfall was investigated it was found that the boundary layer friction and its associated convection produce a low level positive potential vorticity pv band ahead of the hurricane the interaction between the pv band and the eyewall pv ring leads to a temporary weakening and reintensifying cycle asymmetric structures arise from the near discontinuity of the surface friction and the latent heat flux the breaking of the eyewall in the rear quadrants is favorable for the intrusion of the low moist entropy air into the core consequently pv increases significantly in the core in and just above the boundary layer due to the stabilization after the hurricane makes landfall the diabatic heating in the

interaction of two successive alpine deformation fronts constraints from low temperature thermochronology and structural mapping nw iberian peninsula the lateral termination of the alpine pyrenean orogen relief onshore is located in the nw iberian peninsula it overlies a variscan basement iberian massif where the sedimentary record of the alpine tectonic is very scarce thus the characterisation of the tectonic evolution of the lateral termination is difficult and timing and geometries of the main tectonic structures remain unclear combining the tectonothermal histories obtained by modelling of the apatite fission track data aft with structural mapping allows for a comparative study of the different tectonic scenarios and deformation transfer in the lateral termination of an orogen aft ages for the studied area vary from 53 5 12 9 and 222 12 ma from late triassic to early eocene the beginning of the cenozoic cooling episodes is in agreement with the infilling of the tertiary basins late eocene or oligocene calculated uplift for the alpine orogeny is around 2 400 m the cantabrian mountains were uplifted and emplaced southwards and the main period of exhumation began in the palaeogene at rates of 0 02 mm a and continued during the neogene at rates of 0 06 mm a however the galaico leoneses mountains located to the south of the studied area were uplifted and emplaced northwards during the neogene showing more rapid uplift rates of 0 08 mm a suggesting that the western termination of the alpine pyrenean orogen relief is the result of the successive interaction of two alpine deformation fronts

the transition of the hurricane frederic boundary layer wind field from the open gulf of mexico to landfall abstract numerous aircraft ship buoy and land nation data were composited with respect to the center of hurricane frederic for two time periods a 24 h period corresponding to the storm s position in the open gulf of mexico on 12 september 1979 and an 8 h period corresponding to the landfall of frederic near 0400 gmt on 13 september comparison of wind analyses for the two periods indicated a rotation of maximum inflow angles from the southeast to northeast quadrants and a strong frictional decrease of wind speed over land them and other features of the landfall analysis were compared with a model landfall study by moss and jones 1978 the landfall composite wind field was compared with the fujita damage vector analysis to determine the damage time interval and mean wind speed range damage vector directions were found to be well correlated with the surface streamlines with the most severe damage being associated with frederic s northern eyewall ten meter level wind speed data over water vo and

role of sediment in speleogenesis sedimentation and paragenesis although the effects of sedimentation in caves have been recognised for many years its role in speleogenesis is frequently overlooked influxes of sediment into a cave system fundamentally alter the way cave passages develop either by alluviation in a vadose environment forcing lateral corrosion and the development of notches or by upwards dissolution in a phreatic environment through a process known as paragenesis sediment influxes affect the hydrological functioning of a karst aquifer by changing the way conduits behave and subsequently develop both in plan and long section here we give an overview of the mechanisms of cave sedimentation and describe how the process of alluviation and paragenesis affect speleogenesis a characteristic suite of meso and micro scale dissolutional features can be used to recognise paragenetic development which is reviewed here in a vadose environment these include alluvial notches whilst in a phreatic environment half tubes anastomoses and pendants bedrock fins and paragenetic dissolution ramps result using these to identify phases of sedimentation and paragenesis is crucial for reconstructing denudation chronologies from cave deposits we suggest that sedimentation and paragenesis are most likely to occur in certain geomorphological situations such as ice marginal and periglacial environments beneath thick residual soils and where rivers can transport fluvial sediment into a cave either via stream sinks or back flooding

mesoscale and convective scale characteristics of mature hurricanes part i general observations by research aircraft abstract the analysis of instrumented aircraft data from four recent mature hurricanes reveals common mesoscale and convective scale features the structure and organization of the convection precipitation and wind flow are studied by combining the airborne observations using basic instrumentation with quantitative radar measurements three predominant precipitation features seen are 1 the eyewall 2 a stratiform rain region adjacent to and outside the eyewall and 3 rainbands that contain both convective and stratiform regions the eyewall is so named because it surrounds the rain free eye but several additional features distinguish it from other convective bands in the hurricane in particular the updraft tangential wind maximum and highest rainfall have preferred locations relative to each other with the updraft being radially inward from the rain and wind maxima the 10 dbz radar reflectivity contour indicative of the inner edge slopes substantially outward with height and there is evide

a mid miocene to early pleistocene multi level cave as a gauge for tectonic uplift of the swabian alb southwest germany a recently discovered deep cave laierhohle within a plateau of upper jurassic limestone is the deepest 126 m of the southwest german swabian alb providing a unique gauge for crustal tilting and isostatic uplift of the southwest german crust from late mid miocene to earliest pleistocene horizontal levels are considered a product of a stationary palaeo water table vertical shafts are related to base level fall which in turn may be the result of uplift and or incision we correlate speleogenetic with dated geomorphic features and thus come to a chronology of events the laierhohle records five episodes of long term stability of the karst water table covering the time span from late middle miocene until the pliocene pleistocene transition the first two stable episodes can be dated to the late middle miocene and late miocene horizontal levels 1 and 2a an episode responsible for the formation of level 2b falls within early pliocene time levels 3a and 3b are spatially well separated but must have formed within a relatively short time span towards the end of the pliocene in the working area total depth of penetrative karstification was in the order of 120 m this penetration has been accomplished over a period of approximately 12 ma resulting in an average uplift rate of 0 01 mm a

paleoenvironmental evolution of picos de europa spain during marine isotopic stages 5c to 3 combining glacial reconstruction cave sedimentology and paleontological findings abstract in glaciated areas the environmental evolution before mis 2 is usually poorly constrained mainly due to the later glacial erosion during the global last glacial maximum lgm however in carbonate areas karst caves can preserve records of pre lgm paleoenvironment we studied a cave 1350 m altitude to establish the paleoenvironmental evolution of a glaciated karst area in picos de europa sw europe for this objective a glacial reconstruction cave sedimentology analyses and macro and micromammal remains are com bined with ten u th osl and ams 14c ages the paleo glacial reconstruction indicates glaciers descended down to 810 1040 m of altitude covering an area of 36 18 km2 in the surroundings of covadonga lakes during the glacial local maximum with the equilibrium line altitude located at 1524 36 m the geomorphological study of the cave and the u th and osl dates reveal the presence of three allochthonous alluvial sediment sequences at 132 135 98 60 and ca 36 ka these last two sequences would come from the erosion of fluvioglacial sediments including teeth fragments of pliomys coronensis p lenki an unusual species in high areas of nw spain during the upper pleistocene in addition remains of chamois rupicapra pyrenaica dated in 37 33 cal ka bp constitutes the oldest evidence of chamois above 800 m asl in the region all the presented data indicate the development of alpine glacier free areas covered by fluvioglacial sediments at ca 1450 m altitude at 98 60 and 37 33 ka corresponding to glacial retreat stages

a modeling study of orographic convection and mountain waves in the landfalling typhoon nari 2001 in this study the characteristics of mountain induced gravity waves mgws and orographic convection in typhoon nari 2001 and their impacts on the formation of orographic precipitation as nari moved across taiwan s central mountain range cmr are investigated by analyzing the cloud resolving model simulation results in the distant rain band convective cells were triggered frequently on the steep windward slope of cmr and advected downstream simultaneously mgws could exist on the lee side with stable environmental stratification three phases occurred in the mgws convection interaction including the enhancement of mgws and convection breaking and restoring of mgws when the convective cells and mgws were superposed in out of phase the amplitudes of both mgws and convective cells were increased decreased the vertical wavelength of mgws was also increased during the in phase superposition even inducing the further breaking of mgws for the formation of precipitation on the lee side mgws convection interaction contributes on a smaller scale to offset the reduction effect from the larger scale descending moreover convective cells on the windward slope could contribute a large amount of cloud ice and snow particles aloft to seed hydrometeors over the lee side more cloud water was produced by the mgws convection interaction when their amplitudes were increased during the in phase superposition riming and coalescence processes were responsible not only for the windward slope precipitation enhancement but also the secondary precipitation maximum over the lee side therefore the mgws convection interaction could modify the structure of vertical motion and hydrometeors over the lee side and then affect orographic precipitation when nari passed the cmr as nari s eyewall encountered the northern cmr the terrain generated long lasting strong updrafts at the upslope resulting in a doubled rainfall maximum to that in the no terrain sensitivity experiment the downdraft branch of the mgw produced a rain shadow on the lee side copyright 2011 royal meteorological society

the vorticity method extension to mesoscale vertical velocity and validation for tropical storms the vorticity method infers vertical velocity from vorticity variations in space and in time based on the vorticity equation the viability of the large scale vorticity method has been demonstrated in previous studies based on the quasi geostrophic vorticity equation however the extension of the vorticity method to the mesoscale vorticity equation including the vertical stretching and tilting terms is hindered by inseparable variables when formulated in cartesian coordinates in this study the separation of variables for the mesoscale vorticity method is achieved by formulating the mesoscale vorticity equation in lagrangian coordinates in terms of the characteristic line composed of three nonlinear ordinary differential equations a numerical method based on backward integration is also presented to solve the vertical velocity along the characteristic of the mesoscale vorticity equation observing system simulation experiments were undertaken to quantify both the numerical accuracy of the vorticity method and the sensitivities of the kinematic and vorticity methods to errors present in horizontal wind fields with perfect horizontal winds the vertical velocities derived from the kinematic and vorticity methods are identical to the degree of accuracy governed by the truncational errors when error perturbations are included the vertical motions derived from the vorticity method are less susceptible to errors in horizontal winds than the kinematic method this conclusion is consistent with the analytical analysis and numerical results with the large scale vorticity method shown in previous studies the mesoscale vorticity method with the tilting term is shown to be more accurate than the large scale vorticity method in deriving vertical velocities in tropical storms numerical experiments demonstrate that the mesoscale vorticity method can benefit from high temporal resolution data observed by doppler radars to infer the vertical velocity in tropical storms where the inner circulation is dominated by the rotational winds copyright 2003 royal meteorological society

low level kinematic thermodynamic and reflectivity fields associated with hurricane bonnie 1998 at landfall during 11 h on 26 august 1998 two noaa wp 3d aircraft deployed 85 global positioning system gps dropwindsondes within 2 of latitude of the circulation center of hurricane bonnie as it made landfall in north carolina about 75 of the sondes successfully collected data which were used to create a series of storm relative horizontal maps of kinematic and thermodynamic variables from 10 m to 2 km reflectivity fields were analyzed from the weather surveillance radar 1988 dopplers wsr 88ds located at wilmington and morehead city north carolina and the tail and lower fuselage radars aboard the wp 3ds gps sonde performance and deployment spacing is adequate to identify several aspects of the vortex these include 1 warm dry stable air in the offshore flow that results in reduced equivalent potential temperatures entering the southern portion of the eyewall 2 cooler air collocated with the upwelled water in the right rear quadrant and under the eyewall and 3 an atypical radial wind pattern with strong inflow southwest of the circulation center and outflow northeast of the center the strongly asymmetric structure found at 10 m becomes much more homogeneous by 2 km altitude no intense rainbands developed over land in the onshore flow nor did the bands in the onshore flow undergo any significant changes once they made landfall beyond the eyewall the offshore flow contained much less precipitation than the onshore portion of the storm characteristics beyond the eyewall appear to have been modulated by the proximity to land but hurricane intensity did not vary the authors infer that the lower energy content of the inflow was offset by the contraction of the eyewall

polarimetric radar observations of the persistently asymmetric structure of tropical cyclone ingrid abstract tropical cyclone ingrid had a distinctly asymmetric reflectivity structure with an offshore maximum as it passed parallel to and over an extended coastline near a polarimetric weather radar located near darwin northern australia for the first time in a tropical cyclone polarimetric weather radar microphysical analyses are used to identify extensive graupel and rain hail mixtures in the eyewall the overall microphysical structure was similar to that seen in some other asymmetric storms that have been sampled by research aircraft both environmental shear and the land sea interface contributed significantly to the asymmetry but their relative contributions were not determined the storm also underwent very rapid changes in tangential wind speed as it moved over a narrow region of open ocean between a peninsula and the tiwi islands the time scale for changes of 10 m s 1 was of the order of 1 h there were also two distinct types of rainbands observed large scale principal bands with embedded d

a pennsylvanian microbial boundstone dominated carbonate shelf in a distal foreland margin picos de europa province nw spain abstract a pennsylvanian bashkirian moscovian high rising microbial boundstone dominated carbonate platform 12 000 km2 developed in the external margin of a variscan foreland basin intensely studied in the northern domain cuera area the stratigraphy and sedimentology of the southern domain the picos de europa province is here revisited distribution of the bashkirian facies valdeteja formation defines a ramp low angle platform with an internal zone central and eastern sectors of the picos de europa province consisting of huge amounts of massive cement rich microbial boundstones surrounded by an external zone comprising lower slope boundstone derived breccias and basinal lime mudstones from the bashkirian moscovian transition to the early kasimovian picos de europa formation the carbonate platform moderately aggraded acquiring a high rising and flat topped geometry and then prograded rapidly into the external zone where platform derived carbonate sediment and clay sourced from the orogen were deposited seismic scale exposures of the western margin of the shelf show angular bedding relationship between basin toe of slope slope and platform top stratal domains with slope inclination up to 32 and a topographic relief of 550 m the platform evolution above described for the picos de europa province significantly differs with respect to the cuera area where platform mostly prograded during the bashkirian and subsequently aggraded during early moscovian the evolutionary differences between these two carbonate domains which are geographically close are interpreted as changes in tectonic subsidence distribution acting as the major factor controlling the large scale platform geometries in the active foreland basin context finally the tectonic overload due to the emplacement of the cuera thrust sheets during the moscovian kasimovian transition changed the platform growth style from progradational to aggradational and consequently the stacking pattern of the platform top cycles in the picos de europa province

modeling the effects of land sea roughness contrast on tropical cyclone winds abstract the fifth generation pennsylvania state university national center for atmospheric research psu ncar mesoscale model mm5 is used to simulate tropical cyclone tc wind distribution near landfall on an f plane at 15 n the effects of the different surface roughness between the land and sea on the wind asymmetry is examined under a strong constraint of a dry atmosphere and time invariant axisymmetric mass fields the winds are found to adjust toward a steady state for prelandfall 50 100 and 150 km offshore landfall and postlandfall 50 100 and 150 km inland tc positions the tc core is asymmetric even when it lies completely offshore or inland the surface 10 m wind asymmetry at the core for pre post landfall position is apparently related to the acceleration deceleration of the flow that has just moved over the sea land as a response to the sudden change of surface friction for prelandfall tc positions the resulted strong surface inflow to the left and front left relative

age and significance of the quaternary cemented deposits of the duje valley picos de europa northern spain abstract cemented calcareous breccias appear in the picos de europa cantabrian mountains spain resting on glacially abraded surfaces and covered by moraines u th dating of the calcite coating the clasts was successful in two samples the oldest one indicating that the breccias accumulated during or prior to marine isotope stage mis 11 and the youngest indicating later cementation during mis 8 the former introduces a limit for the age of the glaciation preceding the breccias which cannot correspond to an event younger than mis 12 this is the oldest absolute age so far obtained for intercalated glacial interglacial deposits of the iberian peninsula

mountain glaciation and paleoclimate reconstruction in the picos de europa iberian peninsula sw europe abstract geomorphic mapping and stratigraphic analysis of a lake core document the late quaternary glacial history of the central and eastern massifs of the picos de europa northwestern spain the distribution of glacial deposits indicates that at their most advanced positions glaciers occupied 9 1 km2 extended as far as 7 km down valley and had an estimated equilibrium line altitude ela ranging between 1666 and 1722 m radiocarbon dating of sediment deposited in a lake dammed by moraines of this advance show that the maximum glacial extent was prior to 35 280 440 cal yr bp this advance was followed by two subsequent but less extensive late pleistocene advances recorded by multiple moraines flanking both massifs and sedimentary characteristics in the lake deposits the last recognized glacial episode is the 19th century maximum extent of small little ice age glaciers in the highest cirques above 2200 m

accessory chromium spinels their coexistence and alteration in serpentinites abstract accessory chromium spinel occurring in serpentinites is usually altered the extent of this alteration and its relationship to alteration processes such as serpentinization and metamorphism is not defined complicating the use of altered spinel as a petrogenetic indicator here the relationship between different alteration processes and spinel alteration is evaluated in terms of accessory chromium spinel occurring in serpentinites of progressive metamorphism in the eastern central alps two coexisting cr spinels were identified i e an altered fe rich cr spinel i with cr al and an fe poor cr spinel ii with al cr which exsolved a cr fe 3 phase and which resisted alteration alteration of cr spinel i is evident from decreasing al mg and cr values with a trend leading to ferrite chromite trend a an enrichment in cr trend b related to co 2 in the serpentinizing fluid indicated by the presence of carbonate talc or tremolite is superimposed to a alteration is a decomposition of the spinel structure caused by the dissolution of mg al and cr during serpentinization dissolution of cr is favored in a reduced environment whereas reprecipitation occurs under locally oxidizing conditions indicated by the presence of co 2 sio 2 detected in spinel is a relative measure of the degree of alteration metamorphism up to amphibolite facies recrystallized and homogenized preexisting spinel phases to various degrees whether or not and to what extent a spinel alters depends on its fe content fe 2 stabilized in the octahedral site high cfse is responsible for an inverse and less stable spinel structure fe rich spinels cr spinel i are therefore readily subjected to alteration whereas fe poor spinels cr spinel ii are resistant to alteration during the serpentinization processes

the evolution of hurricane danny 1997 at landfall doppler observed eyewall replacement vortex contraction intensification and low level wind maxima danny made landfall as a minimal hurricane on the alabama coast on 19 july 1997 after drifting over mobile bay for over 10 h danny s unusually close proximity to the doppler radar wsr 88d in mobile provided an unprecedented view of the storm s complex and dramatic evolution during a prolonged landfall event over a 1 day period base reflectivity and velocity products were combined with aircraft reconnaissance information to detail the formation of concentric eyewalls and complete evolution of an eyewall replacement cycle this highly symmetric hurricane then underwent a rapid asymmetric transition in mobile bay during which a small eyewall mesovortex developed adjacent to intense convection in the western eyewall radar estimated rainfall increased dramatically during the asymmetric phase rates exceeded 100 mm h21 for nine consecutive hours west of the center while precipitation nearly vanished to the east changes in the distribution of precipitation corresponded with changes in the low level wind velocity structure a 25 h temporal composite of wsr 88d base velocities displayed axisymmetric intensification and contraction of danny s core during the eyewall replacement cycle later the asymmetric phase was dominated by further contraction and intensification on the west side only in the western eyewall a persistent boundary layer wind maximum evolved and contracted to a radius of only 10 13 km from the center concurrently eastside boundary layer winds diminished as the maximum winds rose to 1 1 5 km altitude and the radius expanded danny reached maximum intensity during this asymmetric phase in mobile bay with base velocities 44 m s21 85 kt at 600 m elevation eyewall contraction in the meandering storm combined with climatologically elevated ssts in shallow mobile bay probably played significant roles in danny s continued intensification there discrepancies arose in determining danny s structural patterns intensity and evolution during landfall interpretation varied depending on the type of platform used to observe the storm the continual sampling of the storm by the nearby wsr 88d provided detail not available from aircraft data alone doppler base velocities in the intense westside convection were much stronger than measured at flight level yet the opposite was true in the storm s drier east side doppler radar showed that the westside base velocity maxima were confined to the boundary layer 600 700 m and represented a slightly conservative estimate of maximum surface gusts recorded at dauphin island during the passage of danny s convective eyewall thus winds probably were even stronger at boundary layer levels below the wsr 88d s lowest scan elevation the shallowness and persistence of danny s boundary layer velocity maxima stressed the need for accurate wind information in the lowest few hundred meters of a tropical cyclone s eyewall for a better indication of the storm s true intensity and near surface wind velocities

electrical conductivity of olivine a dunite and the mantle laboratory studies of the electrical conductivity of rocks and minerals are vital to the interpretation of electromagnetic soundings of the earth s mantle to date the most reliable data have been collected from single crystals we have extended these studies with electrical conductivity measurements on a dunite from north carolina in the temperature range of 600 1200 c and under controlled oxygen fugacity observations of conductivity as a function of oxygen fugacity and temperature demonstrate that conduction in the dunite is indistinguishable from conduction in single olivine crystals thus the common practice of exaggerating the single crystal conductivities to account for conduction by grain boundary phases in the mantle is unnecessary because the dunite conductivity is consistent with that published for single crystals under similar conditions we have made a combined analysis of these data conductivity as a function of temperature between 600 and 1450 c displays three conduction mechanisms whose activation energies may be recovered by nonlinear least squares fitting yielding activation energies of 0 21 2 56 10 19 j 0 13 1 60 ev below 720 c 2 56 0 02 10 19 j 1 60 0 01 ev between 720 c and 1500 c and 11 46 0 90 10 19 j 7 16 0 56 ev above 1500 c the behavior of conductivity as a function of oxygen fugacity is well explained by a model in which an o2 independent population of charge carriers is supplemented at high oxygen fugacities with a population that is proportional to o20 3 this parametrization produces a clear correlation of the o2 dependent term with iron content which is otherwise obscured by variations in conductivity among olivines

a piecewise potential vorticity inversion algorithm and its application to hurricane inner core anomalies in this study a piecewise potential vorticity pv inversion algorithm for an arbitrary number of pv pieces is developed by extending wang and zhang s pv inversion scheme and then the nonlinear responses to various types and magnitudes of axisymmetric pv anomalies pvas in hurricane vortices are investigated results show that the upper and lower level pvas in the eye help enhance cyclonic flows in the eyewall but with weak vertical interactions between them the balanced flows corresponding to the pvas in the eyewall appear to account for a substantial portion of the warm core and the minimum pressure in the eye however the lower level pva in the eye inversionlayer is more effective in contributing to the hurricane intensitythan that at the upper levels results also show that the radius of the balanced response of pvas is more sensitive tothemeanvortexintensitythantheverticalpenetration theweakerthemeanvortexintensity thelargerthe radius of the influence will be similar behaviors are also observed for the quasi balanced secondary circulations thatis givenadiabaticheatingprofilein theeyewall theweakerthebackgroundvortexor thepvas the stronger the secondary circulations will be it is found that the development of an outer eyewall or spiral rainbands could be inimical to the inner eyewall in several ways such as by 1 adding an anticyclonic flow inside to offset the cyclonic rotation of the inner eyewall 2 enhancing a ring of a lower pressure zone underneath to broaden the inner core lower pressureregion 3 inducingan inward outward radialflowoutside inside in thepbl upperlevel to block the energy supply to outflow of the inner eyewall and 4 generating subsidence between the two eyewalls to suppress the development of deep convection in the inner eyewall

abrupt glacial valley incision at 0 8 ma dated from cave deposits in switzerland glacial erosion dramatically alters mountain landscapes but the pace at which glaciers carve a previously fluvial landscape remains poorly defined because long term valley incision rates are difficult to measure here we reconstruct the lowering history of the aare valley switzerland over the past 4 m y by dating cave sediments with cosmogenic 26al and 10be incision accelerated from 120 m m y to 1200 m m y at 0 8 1 0 ma at least 1 m y after the onset of local glaciation rapid incision may have been triggered by lowering of the equilibrium line altitude at the mid pleistocene climate transition

the influence of terrestrial run off on marine biotic communities an example from a thrust top carbonate ramp upper pennsylvanian foreland basin picos de europa nw spain article i nfo high diversity marine biotic communities characterize the lower kasimovian upper pennsylvanian carbonates of the las llacerias formation in the andara massif picos de europa province cantabrian mountains spain the carbonates accumulated on a small thrust top ramp system within the shallow low energy and euphotic realms biotic communities were characterized by abundant photozoans calcareous algae and cyanobacteria and heterozoans including filter and suspension feeders calcareous and siliceous sponges bryozoans brachiopods crinoids diverse other metazoans rugose solitary and colonial corals tabulate corals bivalves gastropods and echinoids benthic foraminifers including very abundant small incrusting tubiforms and conspicuous swarms of cement filled spheres calcispheres or penella small sized buildups of chaetetid sponges syringoporids branching rugose corals anthracoporella and phylloid algae commonly developed in these shallow water environments meanwhile mud mounds formed at greater water depths mostly below the lower limit of the phothic zone the occurrence of such diverse biotic communities and the grain composition of the shallow water deposits not recorded in the platform top successions of the antecedent bashkirian moscovian carbonate shelf valdeteja and picos de europa formations are interpreted as linked to increased nutrient levels mesotrophic to mildly eutrophic conditions in the actual sea surface water the nutrients are inferred to have resulted from land derived fluxes from the rivers draining the adjacent growing variscan orogenic chain nutrients were subsequently transported into the narrowed marine shallowing foreland basin located in the eastern side of pangea within the palaeoequatorial humid belt comparison to the pennsylvanian auernig group in the carnic alps allows the discrimination between the influence of land derived versus upwelling derived nutrients providing a useful tool in the interpretation of biotic assemblages in the fossil rock record

constraints on alpine speleogenesis from cave morphology a case study from the eastern totes gebirge northern calcareous alps austria abstract the totes gebirge is the largest karst massif in the northern calcareous alps nca this paper focuses on the eastern part where two major multiphase alpine cave systems burgunderschacht cave system and dof sonnenleiter cave system are described with respect to morphology hydrology and sediments the caves consist of upper miocene galleries of epi phreatic genesis and younger vadose canyon shaft systems morphometrical analyses were used to determine the relevance of 1 cave levels horizontal accumulations of galleries 2 slightly inclined palaeo water tables of speleogenetic phases 3 initial fissures and 4 inception horizons on the development of the cave systems epi phreatic cave conduits developed preferentially along vertical faults and along only a restricted number of bedding planes which conforms to the inception horizon hypothesis for at least one of the systems a development under epiphreatic conditions is certain and a hydrological behaviour in the filling overflow manner is likely observations in further major cave systems in the totes gebirge identify palaeo water tables of speleogenetic phases that show inclinations of 1 5 1 analyses of cave levels reveal distinct peaks for each cave but it is hardly possible to correlate these elevation levels between caves of different parts of the karst massif therefore we conclude that cave levels strictly horizontal indicate speleogenetic phases or palaeo water tables respectively but they cannot be correlated with palaeo base levels or on regional scale an exact correlation between cave development and palaeo base levels at the surface is only possible with inclined palaeo water tables of speleogenetic phases for the totes gebirge the inclination directions of the speleogenetic phases imply that palaeo drainage was radial and recharge was autogenic which is in contrast to observations from other plateaus in the nca differences in fracture properties seem to be the reason for the development of divergent types according to the four state model a simplified model for cave genesis and surface development in this area since the upper miocene is presented

a multi method approach for speleogenetic research on alpine karst caves torca la texa shaft picos de europa spain abstract speleogenetic research on alpine caves has advanced significantly during the last decades these investigations require techniques from different geoscience disciplines that must be adapted to the methodological constraints of working in deep caves the picos de europa mountains are one of the most important alpine karsts including 14 of the world s deepest caves caves with more than 1 km depth a speleogenetic research is currently being developed in selected caves in these mountains one of them named torca la texa shaft is the main goal of this article for this purpose we have proposed both an optimized multi method approach for speleogenetic research in alpine caves and a speleogenetic model of the torca la texa shaft the methodology includes cave surveying dye tracing cave geometry analyses cave geomorphological mapping uranium series dating 234u 230th and geomorphological structural and stratigraphical studies of the cave surroundings the speleodisc method was employed to establish the structural control of the cavity torca la texa 2653 m length 215 m depth is an alpine cave formed by two cave levels vadose canyons and shafts soutirage conduits and gravity modified passages the cave was formed prior to the middle pleistocene and its development was controlled by the drop of the base level producing the development of the two cave levels coevally to the cave levels formation soutirage conduits originated connecting phreatic and epiphreatic conduits and vadose canyons and shafts were formed most of the shafts were created before the local glacial maximum 43 45 ka and only two cave passages are related to dolines developed in recent times the cave development is strongly related to the structure locating the cave in the core of a gentle fold with the conduits geometry and orientation controlled by the bedding and five families of joints

morphometry and distribution of isolated caves as a guide for phreatic and confined paleohydrological conditions isolated caves are a special cave type common in most karst terrains formed by prolonged slow water flow where aggressivity is locally boosted the morphometry and distribution of isolated caves are used here to reconstruct the paleohydrology of a karstic mountain range within a homogenous karstic rock sequence two main types of isolated caves are distinguished and each is associated with a special hydrogeologic setting maze caves form by rising water in the confined zone of the aquifer under the mt scopus group israel confinement while chamber caves are formed in phreatic conditions apparently by lateral flow mixing with a vadose input from above

concentric eye walls secondary wind maxima and the evolution of the hurricane vortex abstract research aircraft observations in recent hurricanes support the model of shapiro and willoughby 1982 for the tropical cyclone s response to circularly symmetric convective heat sources convective rings in both nature and the numerical model the tangential wind commonly increases rapidly just inside the radius of maximum wind and decreases inside the eye near the central axis of the vortex thus both secondary outer wind maxima and eyewall wind maxima often contract as they intensify this response is independent of the horizontal spatial scale of the maximum an outer maximum is frequently observed to constrict about a pre existing eye and replace it this chain of events often coincides with a weakening or at least a pause in intensification of the vortex as a whole the concentric eye phenomenon is a common but by no means universal feature of tropical cyclones it is most frequently observed in intense highly symmetric systems

speleodisc a 3 d quantitative approach to define the structural control of endokarst an application to deep cave systems from the picos de europa spain abstract the influence of geological structure on endokarst can be studied by establishing the relationships between discontinuities faults joints and bedding with a cave survey the cave survey elaborated by speleologists represents the directions and inclinations of the cave conduits and can be compared to the strike and dip of the discontinuities of a karst massif this paper proposes a methodology the speleodisc method which is effective in defining the structural control of the endokarst the method has been designed and applied in a pilot area from the alpine karst massif of the picos de europa where long and deep cave systems are well developed including more than 360 km of conduits in its entirety the method is based on the projection of cave surveys on geological maps and cross sections and the comparison between the direction and inclination of the cave survey data and the geometry of the massif discontinuities in three spatial dimensions 3 d the speleodisc method includes 1 collection and management of topographic information 2 collection and management of cave data 3 definition of the groups of conduits 4 elaboration of geological maps and cross sections 5 collection of discontinuity data bedding faults and joints 6 definition of groups of discontinuities and 7 comparison between the cave conduit groups and the families of discontinuities the speleodisc method allows us define the influence of the major and minor structures on the caves geometry estimating percentage of caves forced by each group of massif discontinuities and their intersections in 3 d nevertheless the speleodisc approach is mainly controlled by 1 the amount and quality of the cave survey data and 2 the abundance of cave deposits covering the conduit which can mask the original geometry

estimating vertical velocity and radial flow from doppler radar observations of tropical cyclones the mesoscale vorticity method mvm is used in conjunction with the ground based velocity track display gbvtd to derive the inner core vertical velocity from doppler radar observations of tropical cyclone tc danny 1997 mvm derives the vertical velocity from vorticity variations in space and in time based on the mesoscale vorticity equation the use of mvm and gbvtd allows us to derive good correlations among the eye wall maximum wind bow shaped updraught and echo east of the eye wall in danny furthermore we demonstrate the dynamically consistent radial flow can be derived from the vertical velocity obtained from mvm using the wind decomposition technique that solves the poisson equations over a limited area domain with the wind decomposition we combine the rotational wind which is obtained from doppler radar wind observations and the divergent wind which is inferred dynamically from the rotational wind to form the balanced horizontal wind in tc inner cores where rotational wind dominates the divergent wind in this study we show a realistic horizontal and vertical structure of the vertical velocity and the induced radial flow in danny s inner core in the horizontal the main eye wall updraught draws in significant surrounding air converging at the strongest echo where the maximum updraught is located in the vertical the main updraught tilts vertically outwards corresponding very well with the outward tilting eye wall the maximum updraught is located at the inner edge of the eye wall clouds while downward motions are found at the outer edge this study demonstrates that the mesoscale vorticity method can use high temporal resolution data observed by doppler radars to derive realistic vertical velocity and the radial flow of tcs the vorticity temporal variations crucial to the accuracy of the vorticity method have to be derived from a high temporal frequency observing system such as state of the art doppler radars copyright 2006 royal meteorological society

development of a deep karst system within a transpressional structure of the dolomites in north east italy abstract the piani eterni karst system is one of the longest and deepest caves of italy situated in the southern sector of the dolomiti mountain range the area where the cave was formed displays peculiar structural settings confined in a tectonic transpressive corridor between two regional thrusts belluno and valsugana during miocene uplift of the range the inheritance of mesozoic structures led to the formation of a deep and wide upward branching flower or palm tree structure cutting the carbonate sequence and exposing the surrounding surface to karst processes after erosion the relative lowering of the hydrologic base level due both to the uplift of the area and then to the carving of deep glacial valleys in the quaternary allowed the formation of paleo phreatic conduits at subsequently deeper levels interconnected by vadose shafts and canyons this work gives a detailed tectonic interpretation of the transpressive structure and picks out the tectonic features most favorable to the karst development a detailed statistical analysis of the distribution and orientation of the karst conduits was performed using 31 km of 3d surveys showing that the development of the cave was strictly guided by a few favorable surfaces of stratigraphic and tectonic origin these features are known in the literature as inception horizons and tectonic inception features respectively cave levels are usually related to lithologic favorable conditions associated with standings of the paleo water table here we suggest that some tectonic surface geometries could have led to the opening of voids in the active tectonic phase leading to the formation of the original proto conduit network different types of tectonic inception features identified in the cave were described in terms of geometry and kinematics tensional fractures as well as fault plane undulations and flexural slip surfaces between beds are described as the most favorable tectonic surfaces for the development of the conduits finally we discuss why transpressional settings and related flower structures in soluble rocks can enhance the karst process allowing the formation of huge and deep karst systems

a steep fronted carboniferous carbonate platform clinoformal geometry and lithofacies picos de europa nw spain a steep margined carbonate platform is developed in the carboniferous synorogenic foreland basin of northern spain dips of 60 90 produced during late carboniferous thrusting enable cross sections of a 4 km wide portion of the marginal area of this platform las llacerias outcrop to be studied in aerial photographs at a seismic scale three stratal domains are observed 1 a horizontal bedded platform 2 a clinoformal bedded margin with a relief of up to 500 m and 3 a low angle toe of slope where slope beds interfinger with basin sediments the slope shows well bedded sigmoidal clinoforms with depositional dips ranging from 15 to 32 based on lithology and stratal patterns four facies groups have been recognized 1 a flat topped platform in which thick algal boundstone skeletal packstone grainstone and peloidal micrite wackestone with a poorly rhythmic character prevail 2 the platform margin and upper slope characterized by microbial boundstone spanning a bathymetric range of 150 m measured from the break of slope 3 a slope predominantly composed of margin derived rudstones and breccias and 4 a toe of slope to basin zone where a cyclic alternation of spiculitic siltstones packstone to grainstone calciturbidites and rudstone breccia is visible five successive stages of platform development are deduced 1 bashkirian flooding of the pre existing serpukhovian platform giving rise to the nucleation of a low angle ramp to the south east of the study area with microbial mud mound accumulations and breccias and calciturbidites on the margins 2 early moscovian an influx of siliciclastic sediment buried part of the platform and reduced the area of carbonate sedimentation 3 moscovian aggradation and progradation of the carbonate system produced an extensive steep margined and flat topped shallow water platform shelf system 4 latest moscovian earliest kasimovian drowning of the platform and 5 kasimovian covering of the platform by marly calcareous ramp sediments

examining polarimetric radar observations of bulk microphysical structures and their relation to vortex kinematics in hurricane arthur 2014 abstractdual polarization radar observations were taken of hurricane arthur prior to and during landfall providing needed insight into the microphysics of tropical cyclone precipitation a total of 30 h of data were composited and analyzed by annuli capturing storm features eyewall inner rainbands and outer rainbands and by azimuth relative to the deep layer environmental wind shear vector polarimetric radar variables displayed distinct signatures indicating a transition from convective to stratiform precipitation in the downshear right to downshear left quadrants which is an organization consistent with the expected kinematic asymmetry of a sheared tropical cyclone in the downshear right quadrant vertical profiles of differential reflectivity zdr and copolar correlation coefficient hv were more vertically stretched within and above the melting layer at all annuli which is attributed to convective processes an analysis of specific differential phase kdp indicated that nonspherical ice particle

karsys hydrogeological 3d modeling of alpine karst aquifers developed in geologically complex areas picos de europa national park spain karst aquifers are valuable groundwater resources whose management requires the use of functioning hydrogeological models the karsys approach provides an explicit 3d conceptual model of the geometry and the functioning of karst aquifers that has been successfully applied in swiss and slovenian aquifers in this work karsys is applied in a complex geological area the picos de europa national park spain the hydrogeological 3d model 500 km2 shows an alpine karst aquifer compartmentalized into 32 groundwater bodies dammed up by subvertical barriers creating elevated saturated zones water tables at 1153 m asl and lower ones water tables at 145 m asl the recharge is through 18 spring catchment areas the groundwater flows to the saturated zones pass through vertical to inclined trajectories and phreatic flows are oriented toward nw ne and n karsys can be applied to any geologically complex area at a regional scale although the geological structure should be simplified and the precision in some places is low nevertheless karsys helps to identify the hydrogeological behavior of karst areas and is a useful guide for future hydrogeological researches

environmental evolution in the picos de europa cantabrian mountains sw europe since the last glaciation abstract the western massif of the picos de europa latitude 43 n longitude 4 5 w includes some of the highest peaks in the cantabrian mountains this massif was heavily glaciated during the last glaciation though the post glacial environmental evolution is still poorly understood using a complementary geomorphological and sedimentological approach we have reconstructed the environmental events occurred in this massif since the last pleistocene glaciation the geomorphological distribution of glacial landforms suggests the occurrence of four main glacial stages maximum glacial advance glacial expansion after the maximum advance late glacial and little ice age moreover a 5 4 m long sedimentary sequence was retrieved from the karstic depression of belbin providing a continuous record of the paleoenvironmental conditions in this area since the last glaciation until nowadays this section suggests that the maximum glacial expansion occurred at a minimum age of 37 2 ka cal bp significantly prior to the global last glacial maximum subsequently periglacial processes prevailed in the mid lands of the massif until glaciers expanded between 22 5 and 18 7 ka cal bp following the melting of the glaciers a shallow lake appeared in the belbin depression lake sediments do not show evidence of a cold stage during the late glacial when moraine systems formed at higher locations the terrestrification of this lake started at 8 ka cal bp and the area turned into grassland at 4 9 ka cal bp the existence of charcoal particles in the sediments of belbin sequence reveals the onset of human occupation in the massif through the use of fire activity for grazing purposes finally the presence of moraines inside the highest northern cirques shows evidence of the last glacial phase that occurred during the little ice age cold event since then the warming climate has led to the melting of these glaciers and periglacial processes prevail in the high lands of the massif

tropical cyclone formation in a sheared environment a case study abstract the development of hurricane danny 1997 from depression to hurricane was examined using cloud to ground lightning data reconnaissance aircraft data and satellite imagery vertical wind shear between 850 and 200 hpa of 5 11 m s 1 produced persistent downshear convective outbreaks that became progressively more intense and closer to the center during the development early in the period the storm intensified steadily in the presence of this downshear convection during the last and most intense outbreak a second vortex appeared to develop within the convection evidence is presented that the new downshear vortex became the dominant vortex and absorbed the original based on these events it is hypothesized that the presence of moderate vertical wind shear accelerated the early development process equivalent potential temperature fields within 500 m of the surface were examined only well after the period of vortex interaction did the characteristic mature tropical cyclone radial profile of eq

asymmetric distribution of convection associated with tropical cyclones making landfall along the south china coast this study examines the convection distribution associated with 18 tcs that made landfall along the south china coast during 1995 and 2005 cloud top temperatures from high resolution satellite imageries of the geosynchronous meteorological satellite 5 are used as proxy of strong convection it is found that convection tends to be enhanced on the western side of the tc as it makes landfall in 10 of the cases in agreement with the conclusion of some previous studies four cases have stronger convection on the eastern side this deviation from the general rule appears to be related to the tcs being more slow moving or their interaction of the tc with another land surface prior to its making landfall along the south china coast for the remaining cases in which no significant asymmetries in convection can be identified the vertical wind shear appears to enhance convection on the east side

radon emanation coefficients of several minerals how they vary with physical and mineralogical properties the escape rates of radon gas from rocks and minerals are of great relevance to many branches of geosciences and it is thus important to understand the physical and mineralogical properties that control radon emanation rates mechanisms of radon loss from minerals have direct bearing on the reliability of u pb and u th he geochronology fourteen minerals from three different mineral groups and with localities spanning three continents were selected for this study the radon emanation coefficients rec for each mineral were measured as a function of grain size temperature 238 u and 232 th activities total absorbed dose density and mineral melting temperature the measured 238 u and 232 th activities ranged from 0 01 to 6487 bq g and from below detection limit to 776 bq g respectively the rec values for unheated pulverized samples ranged from 0 083 to 7 0 which is comparable to previously reported ranges except for zircon an inverse correlation between grain size and rec was observed full annealing of fission tracks resulted in an overall decrease in rec values suggesting that nuclear tracks could possibly act as conduits for radon release while activity dose density and melting temperatures are not strongly correlated with rec values it was observed that minerals with high melting points 1400 c have lower rec values most likely due to inhibition of radon release by compact crystal lattice structures this is the first attempt to our knowledge to correlate rec values with melting temperature and this study reports six minerals for which no rec values have been previously reported

speleogenesis in highly geodynamic contexts the quaternary evolution of monte corchia multi level karst system alpi apuane italy abstract the mt corchia karst system is one of the most important and famous caves in the world different from many other large caves here the geological structure has had only a minor role on the vertical multi level pattern of the cave a detailed geomorphic and morphometric analysis of the cave and a preliminary study of cave sediments along with new datings of speleothems allow us now to depict the multistage evolution of this cave which produced at least three major paleo phreatic levels related to different base level stages the analysis of the directions of cave passages shows that the three main phases have different orientations which can be attributed to the different surface morphology during speleogenesis in former times chronological constraints and geomorphic features suggest that the upper part of mt corchia cave developed during the end of pliocene in a stage of favourable climatic conditions and with a moderate tectonic uplift rate the morphological features and the nature of sediments in the upper paleo phreatic level at 1350 1450 m above present sea level apsl imply the occurrence of a wide allogenic catchment area this drainage pattern persisted also in the following stage during a significant but slow lowering of the base level which allowed the formation and the intense vadose rearrangement of the epi phreatic network around 1100 1250 m apsl an uplift stage in the early pleistocene caused the capture of the basins and the loss of allogenic feeding a third epi phreatic level was formed at around 900 m apsl when the catchment area was reduced to the present extent of carbonate rock more than 1 ma ago the recent evolution is due to rapid uplift and to the progressive incision of surrounding basins which led to the lowering of the local base level and to a readjustment of the cave system in order to adapt to a new equilibrium with the present elevation of the springs

single doppler radar observation of the concentric eyewall in typhoon saomai 2006 near landfall 1 landfalling typhoon saomai 2006 was observed by the cinrad wsr 98d radar on the southeast coast of china this study documents the formation and evolution of a concentric eyewall episode using the axisymmetric circulation derived from the ground based velocity track display technique saomai s outer eyewall formed after reaching its peak intensity 5 hours before landfall updraft tangential wind maximum and shallow low level inflow coincided with the high reflectivity and voriticity ring in both inner and outer eyewalls surrounding a moat region characterized by weak downward motion and lower reflectivity the subsidence and rain free moat region between the two eyewalls was filled with rain and upward motion prior to landfall indicating a breakdown in the outer eyewall which was a barrier to radial inflow meanwhile the outer vorticity maximum flattened and the central pressure dropped 9 hpa the eyewall replacement cycle didn t complete probably due to the landfall

chromite from the blue ridge province of north carolina accessory chromite in dunite shows a variety of textures that indicate alteration one group type a consists of four types of chromite clean chromite lattice chromite in which the invading chlorite occurs along three directions in the 100 plane optically zoned chromite and poikiloblastic chromite most of type a chromites are surrounded by chromian clinochlore the other group type b consists of euhedral to subhedral chromite grains which are included in olivine or pyroxene the accessory chromites define a trend exhibited by chromite from other areas that have undergone metamorphism olivine spinel geothermometry indicates equilibration temperatures near 700 degrees c roughly consistent with mineral assemblages in the host gneisses thus the blue ridge dunites are metamorphic rocks and not primary mantle peridotites modified journal abstract

evidence of inception horizons in karst conduit networks this paper outlines the conclusion from an analysis of 18 large cave systems around the world comprising more than 1500 km of conduits the 3d geometry of complex cave systems have been analysed in relation to their geological context as well as their hydrogeological boundary conditions the methodology allowed for the first time statistical evidence of the inception horizon concept thereby it confirms that the development of karst conduits under phreatic conditions is strongly related to a restricted number of so called inception horizons an inception horizon is a part of a rock succession that is particularly susceptible to the development of karst conduits because of physical lithological or chemical deviation from the predominant carbonate facies within the limestone sequence it passively or actively favours the localisation of dissolutional voids

geomorphic mapping in endorheic catchments in the spanish pyrenees an integrated gis analysis of karstic features abstract digital elevation models dems can be useful tools to assess morphologically and hydrologically active processes this paper presents a method to obtain accurate dems an analysis of dem errors and the benefits of gis techniques for mapping geomorphological features and active processes in the karstic endorheic catchment with three permanent lakes estana lakes in the external ranges of the spanish pyrenees field work revealed the lack of accuracy in the original dem a method was then proposed to obtain a hydrologically correct dem using a total topographic station tts and a global positioning system gps on a regular grid 246 topographic points were recorded with a gps and 237 points were measured with a tts on areas of gentle slope the mean and standard deviation of the error of the corrected dem were 1 5 and 3 2 m respectively by using a combined flow algorithm a flow accumulation map was derived from the corrected dem and the study area was divided into fifteen sub catchments the values of the indices of watershed circularity and elongation have a strong variation and the map of flow length also showed strong asymmetry maps of land use topography and lithology were created in order to establish the basis for mapping main geomorphological features the new dem also provided a basis for calculating the topography factor ls in rusle an empirical soil erosion model a map showing the error of the original dem indicates that the highest error values occur in the main karstic features of the geomorphological map hence the proposed methodology including dem correction is useful for an accurate assessment of topographical and geomorphological features in karstic environments

glacial origin for cave rhythmite during mis 5d c in a glaciokarst landscape picos de europa spain abstract laminated slackwater deposits have been identified in many karst caves related to fluvial and lacustrine sedimentation however sedimentological evidence rarely supports a glacial origin for these deposits which was proposed by previous studies the torca la texa shaft is located in a glaciokarst area that comprises numerous slackwater type deposits piled up in fining upward sequences a basal sandy erosive layer and millimeter sized laminated rhythmite with interbedded flowstone characterize these sequences fining upward layers of carbonate silt clay and minor quartz sand deposited in flooded conduits define the rhythmite lamination the presence of allochthonous minerals indicates that the rhythmite sediment comes from the glacial erosion of nearby carbonate mountains two 234u 230th radiometric ages dated the rhythmite deposits around 109 and 95 ka coinciding with relative cold periods included in the mis 5d c these cold periods were marked by a high annual seasonality immediately after the glacial local maximum extension in agreement with a varve type deposit the combination of these sedimentological mineralogical geomorphological and paleoclimate information indicates that the rhythmite should be introduced into the studied cave during the summer melting of the glaciers which produced the recharge of the karst aquifer triggering cave floods in addition punctual glacier collapses would also have their imprint in the slackwater sequences with thicker coarser and erosive sand deposits and the spring blocking by glaciers may have promoted floods inside the cave therefore the studied rhythmite can be interpreted as glacial varves decanted during the relatively cold climate conditions

the impact of t trec retrieved wind and radial velocity data assimilation using enkf and effects of assimilation window on the analysis and prediction of typhoon jangmi 2008