the skaergaard layered series part ii magmatic flow and dynamic layering re examination of textural and structural features of the skaergaard intrusion has clarified the process responsible for various forms of layering two general types are distinguished one produced by magmatic flow and another by non dynamic processes such as compaction and varied nucleation and growth of crystals our concern here is mainly with layering of the first type magmatic flow results in contrasting layers and strong foliation accompanied by a linear orientation of elongated minerals it is associated with slumping and cross bedding in a zone near the margins of the intrusion rocks in the interior of the layered series are foliated and commonly layered but have little or no lineation their layering cannot be due solely to deposition from currents the principal structural elements produced by dynamic processes in the magmatic state foliation lineation shear zones folds and current structures define parallel belts mainly around the western and northern margins their distribution suggests that the strongest component of flow was for the western side and that its strength decreased toward the east shear flow trajectories deduced from lineations and kinematic indicators confirm this asymmetry and point to mass movement toward the southeastern part of the floor

influences of the sierra nevada on intermountain cold front evolution abstractrecent studies indicate that strong cold fronts develop frequently downstream of the sierra nevada over the intermountain west to help ascertain why this paper examines the influence of the sierra nevada on the rapidly developing intermountain cold front of 25 march 2006 comparison of a weather research and forecasting wrf model control simulation with a simulation in which the height of the sierra nevada is restricted to 1500 m roughly the elevation of the valleys and basins of the intermountain west shows that the interaction of southwesterly prefrontal flow with the formidable southern high sierra produces a leeward orographic warm anomaly that enhances the cross front temperature contrast several processes generate this orographic warm anomaly including flow modification by the sierra nevada i e windward blocking of low level pacific air leeward subsidence and increased southerly flow from the mojave desert and lower colorado river basin into the intermountain west diabatic hea

climatology of strong intermountain cold fronts abstract motivated by the intensity and severity of winds and temperature falls that frequently accompany rapidly developing cold fronts in northern utah this paper presents a 25 yr climatology of strong cold frontal passages over the intermountain west and adjoining western united states using conventional surface observations and the north american regional reanalysis strong cold frontal passages are identified based on a temperature fall of 7 c or greater in a 2 3 h period a concurrent pressure rise of 3 hpa or greater and the presence of a large scale 700 hpa temperature gradient of at least 6 c 500 km 1 the number of strong cold frontal passages exhibits a strong continental signature with very few events 10 along the pacific coast and more than 200 events east of the continental divide the number of events increases dramatically from the cascade mountains and sierra nevada to northern utah indicating that the intermountain west is a frequent cold front breeding ground a composite of th

late quaternary terraced marine deposits as tools for wide scale correlation of unconformity bounded units in the volcanic aeolian archipelago southern italy abstract late quaternary raised terraced marine deposits are commonly interlayered with volcanic deposits along the coasts of the aeolian archipelago they mostly reflect the interplay between long term crustal vertical movements and glacio eustatic sea level changes during marine isotope stages mis 5 and 9 key discontinuity surfaces are represented by those bounding terraced marine deposits formed in correspondence of recurrent individual interglacial sea level peaks they are the basal ravinement surface formed during gradual sea level rise at the onset of a sea level peak and the upper surface of subaerial erosion developed during ensuing sea level fall and lowstand the discontinuity surfaces are classified according to their sequence stratigraphic significance field documentation and areal extent mis 5 marine deposits are bounded by the first order ui and uii unconformities the ui unconformity is the ravinement surface formed during mis 5e sea level rise age between 130 and 124 ka the uii unconformity is the surface of subaerial erosion and non deposition developed during sea level lowering after mis 5a age 70 ka unconformities ui and uii are correlated throughout the entire aeolian archipelago thus assuming a regional stratigraphic significance by linking to the global sea level curve they are assigned a relative age and assume a substantial chronostratigraphic significance and potential for dating of volcanic rocks further correlation on most of the aeolian archipelago is provided by the l3 unconformity that is the ravinement surface formed during sea level rise of mis 5c 100 ka moreover the f1 unconformity bounds at the base marine deposits older than the last interglacial i e mis 9 and is ascribed of an inter island stratigraphic outcome these allogenic unconformities driven by sea level fluctuations allow definition of a regional unconformity bounded framework for the aeolian archipelago into which local volcanic successions subdivided by autogenic unconformities of volcanic origin may be arranged

on the use of unconformities in volcanic stratigraphy and mapping insights from the aeolian islands southern italy abstract the approach to volcanic stratigraphy and mapping in the aeolian islands has found the concept of unconformity bounded units ubus extremely useful for purposes of stratigraphic classification and correlation volcanic unconformities erosive and collapse unconformities relative to processes of internal modification of a volcano are classified separately from sea level driven unconformities the erosive unconformities formed during periods of volcanic quiescence are generally characterized by angular relationships and lithological change between the products below and above an unconformity and may be associated with paleosols or epiclastic horizons the collapse unconformities related to calderas and lateral collapses represent surfaces of structural truncation along the collapse borders passing outside of the collapse to erosive unconformities developed during the corresponding repose periods instead the sea level driven unconformities are marine and subaerial erosive surfaces bounding in pairs the depositional cycles relative to sea level highstands which are recorded in raised marine terraces most unconformities can be correlated on a variable scale from local volcanic island to regional inter island by means of careful stratigraphic analysis targeted to identify the corresponding stratigraphic hiatus in the volcanic successions in different points of observation this helps to solve the problems arising from the difficult recognition of the unconformities in the field moving away from the type locality due to their variable features a practical nomenclature scheme for a hierarchy of ubus to be applied in volcanic areas can be established on the basis of the areal magnitude of the bounding unconformities and their importance in the volcano history passing through a slight modification of the international stratigraphic guide s rules combined with lithostratigraphic units mapped rock bodies and lithosomes eruptive centres the ubus provide a useful stratigraphic synthesis of a volcanic area by means of a framework of time stratigraphic unconformable surfaces moreover ubus can be directly interpreted in terms of volcanic activity units with a time stratigraphic significance thus providing the key elements for the eruptive history of a volcano and the definition of its event stratigraphy

oxygen isotopes and sea level from the time that detailed oxygen isotope records derived from foraminifera living in the constant temperature environment of the abyssal ocean became available there has been a discrepancy between the ice volume record that these records imply and that derived from the altitude of dated coral terraces around the world here we re examine the data and conclude that the temperature of the abyssal ocean has been an actively varying component of the climate system

a short lived cold front in the southwestern united states a cold front developed in arizona in a region of initially small temperature gradient developing to great intensity accompanied by damaging winds over new mexico and then losing strength over the high plains of oklahoma and texas the entire development of frontogenesis and frontolysis occurred in no more than 24 h the initial growth of temperature contrast was attributable mainly to horizontal variation of surface heat flux during the morning with little heating in a region of dense cloud cover and scattered showers in the west and with intense heating in a region of only thin high clouds to the east the accompanying ageostrophic circulation then resulted in a collapse toward discontinuity the frontal zone maintained an approximately steady state for a few hours in early afternoon at this time the westerly component of surface wind just ahead of the zone was not as strong as the eastward motion of the zone the passage of the zone was accompanied by a veering and strengthening of the surface wind so that westerly components were briefly larger than the frontal motion the tendency of the convergent wind field to produce a frontogenesis was evidently balanced by small scale mixing subsequently the pressure trough and surface wind shift propagated eastward more rapidly than the frontal temperature contrast the contrast quickly weakened as the mixing then was unopposed severe convection developed during the evening as the convergent surface wind shift came into contact with humid unstably stratified air

diurnal variation of downslope winds in owens valley during the sierra rotor experiment abstract the impact of diurnal forcing on a downslope wind event that occurred in owens valley in california during the sierra rotors project srp in the spring of 2004 has been examined based on observational analysis and diagnosis of numerical simulations the observations indicate that while the upstream flow was characterized by persistent westerlies at and above the mountaintop level the cross valley winds in owens valley exhibited strong diurnal variation the numerical simulations using the coupled ocean atmosphere mesoscale prediction system coamps capture many of the observed salient features and indicate that the in valley flow evolved among three states during a diurnal cycle before sunrise moderate downslope winds were confined to the western slope of owens valley shallow penetration state surface heating after sunrise weakened the downslope winds and mountain waves and eventually led to the decoupling of the well mixed valley air from the westerlies aloft around local noon decoupled

submarine depositional terraces in the tyrrhenian sea as a proxy for paleo sea level reconstruction problems and perspective abstract in the last decade great effort was put in the study of relative sea level changes on mediterranean coastlines through the integration of geophysical modelling and proxy data of paleo shorelines in this paper we show potential and limitations of using additional marine geomorphic sedimentary markers for earlier and lower sea levels these markers are submarine depositional terraces sdts i e deposits formed by a set of small prograding sedimentary wedges having a terraced shape and found at variable shallow water depths mainly the first 150 m on continental and insular shelves in the tyrrhenian sea the shallowest terraces near shore have their edges at depths between 10 m and 30 m approximating the modern local storm wave base level their formation is thought to be associated with the modern sea level highstand and thus can be used as the modern analogue for deeper terraces formed in the past when the sea level was on the middle and outer shelf mid shelf terraces have their edges at variable depths between 40 m and 90 m and probably formed during the last sea level rise they show a patchy spatial distribution and a large variability in their internal structure so that they are not suitable for correlation on a regional scale shelf edge terraces have their edges at depths between 120 m and 170 m which is close or deeper than the last glacial maximum lgm sea level stand they show a remarkable lateral continuity and a prograding internal structure similar to those at shallower depth and thus represent a proxy for the sea level position at around 20 ka however the position of sdts edges is not a direct measure of paleo sea level positions because their depth depends on a complex interplay of several factors such as the base of the storm wave and its variation in response to coastal physiography as well as the occurrence of subsequent erosional or depositional processes depending on the geophysical and mapping methods used to determine their depth the associated error range can also differ based on the analysis of these complexities and a wide range of physiographic settings of the tyrrhenian sea we discuss these error ranges in order to assess potential and limitation of the sdt for analyses of vertical mobility of an area

life cycle and mesoscale frontal structure of an intermountain cyclone abstract high resolution analyses and mesowest surface observations are used to examine the life cycle and mesoscale frontal structure of the tax day storm an intermountain cyclone that produced the second lowest sea level pressure observed in utah during the instrumented period and the strongest cold frontal passage at the salt lake city international airport in the past 25 years a key mesoscale surface feature contributing to the cyclone s evolution is a confluence zone that extends downstream from the sierra nevada across the great basin strong contraction i e deformation and convergence within this great basin confluence zone gbcz forms an airstream boundary that is initially nonfrontal but becomes the locus for surface frontogenesis as it collects and concentrates baroclinicity from the northern great basin including that accompanying an approaching baroclinic trough evaporative and sublimational cooling from postfrontal precipitation as well as cross front contrasts in surface sensible

discrete frontal propagation over the sierra cascade mountains and intermountain west abstract on 25 march 2006 a complex frontal system moved across the sierra cascade mountains and intensified rapidly over the intermountain west where it produced one of the strongest cold frontal passages observed in salt lake city utah during the past 25 yr observational analyses and numerical simulations by the weather research and forecast wrf model illustrate that the frontal system propagated discretely across the sierra cascade mountains and western nevada this discrete propagation occurs in a synoptic environment that features a mobile upper level cyclonic potential vorticity pv anomaly that is coupled initially with a landfalling pacific cyclone and attendant occluded front the eastward migration of the upper level cyclonic pv anomaly ultimately encourages the development of a new surface based cold front ahead of the landfalling occlusion as troughing confluence and convergence downstream of the sierra nevada intensify preexisting baroclinity over nevada trajectories show that the n

moist dynamics and orographic precipitation in northern and central california during the new year s flood of 1997 abstract the dynamics of moist orographic flows during the january 1997 floods in northern and central california are investigated using numerical simulations computed with the fifth generation pennsylvania state university national center for atmospheric research psu ncar mesoscale model mm5 early in the event 31 december 1996 1 january 1997 the low level winds offshore of california s central coast were blocked by the topography of the santa lucia range and the low level winds in the central valley were blocked by the topography of the central sierra nevada range in contrast moisture laden winds along the northern coast ranges and the northern sierra nevada flowed over topographic barriers as the core of humid air migrated to the south over 24 h the low level barrier jets weakened as the atmospheric stability decreased bringing heavy rainfall to the central and southern sierra nevada at the end of the event the heavy precipitation during this event was largely controlled by the interactio

orographic precipitation and air mass transformation an alpine example a case of orographic precipitation in the alps on 20 september 1999 was studied using several models along with rain gauge and radar data the objective of the study is to describe the orographic transformation of an air mass including multi scale aspects several new and some conventional diagnostic quantities are estimated including drying ratio precipitation efficiency buoyancy work condensed water residence time parcel changes in heat moisture and altitude and dominant space and time scales for the case considered the drying ratio was about 35 precipitation efficiency values are ambiguous due to repeated ascent and descent over small scale terrain the sign of buoyancy work changed during the event indicating a shift from stratiform orographic to weak convective clouds cloud water residence times are different for the two mesoscale models 400 compared to 1000 s due to different cloud physical formulations the two mesoscale models agree that the dominant spatial scale of lifting and precipitation is about 10 km smaller than the scale of the main alpine massif trajectory analysis of air crossing the alps casts doubt on the classic model of fohn few parcels exhibit classic pattern of moist ascent followed by dry descent parcels that gain latent heat descend only briefly before rising into the middle troposphere parcels that descend along the lee slope originate in the middle troposphere and gain little or even lose latent heat during the transit as parcels seek their proper buoyancy level downstream a surprising scrambling of the air mass occurs radar data confirm the model prediction that the rainfall field is tightly controlled by local terrain on scales as small as 10 km rather than the full 100 km cross alpine scale a curious pulsing of the precipitation is seen indicating either drifting moisture anomalies or weak convection copyright 2003 royal meteorological society

terrain influences on synoptic storm structure and mesoscale precipitation distribution during ipex iop3 abstract the influence of topography on the evolution of a winter storm over the western united states and distribution of precipitation over northern utah are examined using data collected during the third intensive observing period iop3 of the intermountain precipitation experiment ipex the analysis is based on high density surface observations collected by the mesowest cooperative networks special radiosonde observations wind profiler observations next generation weather radar nexrad data and conventional data a complex storm evolution was observed beginning with frontal distortion and low level frontolysis as a surface occluded front approached the sierra nevada as the low level occluded front weakened the associated upper level trough moved over the sierra nevada and overtook a lee trough the upper level trough which was forward sloping and featured more dramatic moisture than temperature gradients then moved across nevada with a weak surface reflection as a pressure trough over no

sea level history during the last interglacial complex on san nicolas island california implications for glacial isostatic adjustment processes paleozoogeography and tectonics abstract san nicolas island california has one of the best records of fossiliferous quaternary marine terraces in north america with at least fourteen terraces rising to an elevation of 270 m above present day sea level in our studies of the lowest terraces we identified platforms at 38 36 m terrace 2a 33 28 m terrace 2b and 13 8 m terrace 1 uranium series dating of solitary corals from these terraces yields three clusters of ages 120 ka on terrace 2a marine isotope stage mis 5 5 120 and 100 ka on terrace 2b mis 5 5 and 5 3 and 80 ka mis 5 1 on terrace 1 we conclude that corals on terrace 2b that date to 120 ka were reworked from a formerly broader terrace 2a during the 100 ka sea stand fossil faunas differ on the three terraces isolated fragments of terrace 2a have a fauna similar to that of modern waters surrounding san nicolas island a mix of extralimital southern and extralimital northern species is found on terrace 2b and extralimital northern species are on terrace 1 on terrace 2b with its mixed faunas extralimital southern species indicating warmer than present waters are interpreted to be from the 120 ka high sea stand reworked from terrace 2a the extralimital northern species on terrace 2b indicating cooler than present waters are interpreted to be from the 100 ka sea stand the abundant extralimital northern species on terrace 1 indicate cooler than present waters at 80 ka using the highest elevations of the 120 ka platform of terrace 2a and assuming a paleo sea level of 6 m based on previous studies san nicolas island has experienced late quaternary uplift rates of 0 25 0 27 m ka these uplift rates along with shoreline angle elevations and ages of terrace 2b 100 ka and terrace 1 80 ka yield relative local paleo sea level elevations of 2 to 6 m for the 100 ka sea stand and 11 to 12 m for the 80 ka sea stand these estimates are significantly higher than those reported for the 100 ka and 80 ka sea stands on new guinea and barbados numerical models of the glacial isostatic adjustment gia process presented here demonstrate that these differences in the high stands are expected given the variable geographic distances between the sites and the former laurentide and cordilleran ice sheets moreover the numerical results show that the absolute and differential elevations of the observed high stands provide a potentially important constraint on ice volumes during this time interval and on earth structure

the skaergaard layered series part vii sr and nd isotopes the initial isotopic ratios of strontium and neodymium in the skaergaard layered series vary both vertically and laterally on every scale from the intrusion as a whole down to coexisting minerals in a single rock the magma that filled the skaergaard chamber was contaminated to various degrees with the metamorphic rocks through which it rose and was never completely homogenized after being intruded the contamination was most pronounced in contact zones and aureoles around rare xenoliths the greater concentrations of lithophile trace elements in the upper border series was previously attributed to assimilation of buoyant fragments of gneiss that collected under the roof but most of the rocks of the upper border series are isotopically indistinguishablefromthoseofthelayeredseries itisdoubtful therefore that this part of the intrusion assimilated much more of the metamorphic basement than did the rest of the magma similarly the marked increase in the concentrations of excluded elements in the upper part of the layered series is not matched by a change in the isotopic character of the rocks and cannot be attributed to a later influx of new magma analyses of minerals separated from rocks with exceptionally mafic or felsic modal compositions revealed marked inhomogeneities in the isotopic compositions of their constituent minerals for example coexisting plagioclase and pyroxene from closely associated anorthosites and pyroxenites have very different initial isotopic ratios of both strontium and neodymium the same is true of mafic and felsic layers in modally graded gabbros these differences are unrelated to the low temperature alteration shown by oxygenisotopes they must have been introduced when the original gabbro was largely crystallized and underwent local metasomatic replacement by nearly mono mineralic mafic and felsic assemblages

late quaternary ancient shorelines at lipari aeolian islands stratigraphical constraints to reconstruct geological evolution and vertical movements indicators of three fossil shorelines located at elevations of 43 45 m asl i order 23 27 m ii order and about 12 m iii order are recognized on the island of lipari detailed evaluation of the stratigraphic relationships to the volcanic substratum allows their correlation with late quaternary eustatic highstands of tyrrhenian age corresponding to marine oxygen isotope substages 5e 124 ka 5c 100 ka and 5a 81 ka marine deposits related to the ancient shorelines represent useful stratigraphic markers as related unconformities constrain the geological evolution of lipari this is interpreted as a result of two main stages of volcanic activity pre and post tyrrhenian spaced out by one stage characterized by prevalent marine erosional episodes tyrrhenian chronological and altimetrical data concerning the ancient shorelines have been used to estimate the vertical mobility of the volcanic edifice of lipari which is characterized by a continuous uplift at an average rate of 0 34 mm a during the last 125 ka this estimation is fully concordant with the values obtained during the same time period from the nearby islands of filicudi 0 31 mm a and salina 0 36 mm a suggesting a similar uplift trend induced by the prevalence of regional tectonic processes

late quaternary deformation history of the volcanic edifice of panarea aeolian arc italy a series of raised palaeoshorelines is documented along the emergent coastal slopes of panarea and surrounding islets at elevations of 115 palaeoshoreline ia and 100 m a s l ib 62 5 m ii 35 m iii 12 m iv 10 12 va and 5 m vb according to stratigraphic constraints and cross cutting relationships these palaeoshorelines are correlated with discrete high sea level stillstands during marine oxygen isotope stages mis 5e 5c 5a and 3 coastal elevation changes suggest the occurrence of a long term sustained uplift trend of the volcanic edifice since the last interglacial last 124 ka the uplift rates are not constant but display a progressive deceleration from maximum values of 1 5 1 58 m ka in the period between 124 and 100 ka down to the lowest values of 0 66 0 69 m ka which tend to be constant starting from 81 ka bp the long term deformation pattern of panarea suggests that a transitory volcano related component of uplift interplayed with the regional tectonic component affecting the sub volcanic basement which has undergone a persistent and widespread uplift since the mid pleistocene the volcano related component of uplift prevailing between 124 and 100 81 ka is interpreted as the result of visco elastic deformation mechanisms which characterize the progressive re equilibration of the shallow magmatic system following the incoming quiescence of the volcanic edifice the long term uplift values at panarea are higher than in the main portion of the western central aeolian arc where a mean uplift rate of 0 34 m ka was estimated since the last interglacial last 124 ka such a pattern of deformation on a regional scale may be a response to active deformation processes connected with the southeastward rollback of the subducting ionian slab which is still active only in correspondence with the eastern sector of the aeolian arc including panarea in the short term a localized submergence trend has been documented at the nearby islet of basiluzzo for the last 2 000 years likely connected to neo tectonic movements along main ne sw trending faults

the influence of mesoscale orography on a coastal jet and rainband abstract the role of mesoscale orography along the central california coast in the development and evolution of a coastal jet and rainband is investigated using a high resolution triply nested nonhydrostatic numerical model comparison of the model simulations which use horizontal grid increments of 5 and 2 km on the inner computational meshes with a coastal mesoscale observation network indicates that the finescale structure of the jet and rainband dynamics are adequately simulated although phase and orientation errors occur the observed and simulated near surface winds have maximum speeds that exceed 22 m s 1 and a direction nearly parallel to the coastline and topography force balance analysis indicates that blocking in the lowest 500 m and flow over the coastal range above this layer contribute to mesoscale pressure perturbations including pressure ridging upstream of the coastal mountains which forces the ageostrophic dynamics of the coastal jet pressure perturbations associated with the to

new insights on the subsidence of lipari island aeolian islands southern italy from the submerged roman age pier at marina lunga abstract lipari island belongs to the aeolian archipelago located in the southern tyrrhenian sea italy which is one of the most active volcanic areas of the mediterranean basin although this region has been settled since prehistory only during roman times were coastal installations built in these islands in this study we present and discuss data on the relative sea level change estimated from a submerged pier of roman age dated 2100 100 bp this structure about 140 60 m is located along the coast of marina lunga corresponding to the present location of the main harbor of lipari island this pier which was accidentally discovered in 2008 during preliminary excavations for the construction of a new pier is a valuable indicator of relative sea level changes and vertical land movements its top surface is presently located at 9 1 0 05 m while the foundations at the outer end of the pier are at 11 6 0 05 m above a shoreline placed at 13 0 0 05 m we studied this site through direct archaeological investigations and ultra high resolution multibeam bathymetry the current submergence of this pier can be explained by the cumulative effect of the relative sea level changes caused by the regional glacio hydro isostatic signal active since the end of the last glacial maximum and the local volcano tectonic land subsidence from our investigations a relative sea level change at 12 3 0 7 m with a subsidence rate at 5 79 0 01 mm y 1 and an average value of volcano tectonic contribution at 5 17 0 01 m y 1 for the last 2100 100 years bp is estimated from comparison against the latest predicted sea level model for the southern tyrrhenian sea these rates of relative sea level change led to the disuse of the harbor after around the fourth century ad in agreement with archaeological interpretations our results provide new insights on the recent evolution of this active volcanic area

an observational and numerical study of a cold front interacting with the olympic mountains during coast iop5 abstract this paper documents the three dimensional flow and precipitation structures associated with a weak cold front interacting with the olympic mountains and the subsequent development of a puget sound convergence zone this study utilizes data collected during coast iop5 the fifth intensive observing period of the coastal observation and simulation with topography field experiment that took place on 11 12 december 1993 one of the most important data sources was a noaa p 3 aircraft which provided flight level data radar reflectivity and doppler winds as it circumnavigated the olympics initially frontal passage along the western foothills of the olympics was accompanied by a 2 3 c temperature drop a rapid wind shift to northwesterlies and an intense line of precipitation 35 45 dbz however the wind shift and associated precipitation structures attenuated when the front began to ascend the windward slopes of the olympics surface and p 3 observations document the deformation of the front

evidence of active subsidence at basiluzzo island aeolian islands southern italy inferred from a roman age wharf abstract the aeolian arc southern tyrrhenian sea italy is one of the most active volcanic areas of the mediterranean basin affected by volcanic hydrothermal and seismic activity ancient populations settled this region since historical times building coastal installations which currently are valuable archaeological indicators of relative sea level changes and vertical land movements in this study we show and discuss data on the relative sea level change estimated from a submerged wharf of roman age dated between 50 b c and 50 a d located at basiluzzo island this structure has been studied through marine surveys and archaeological interpretations and is presently located at a corrected depth of 4 10 0 2 m we explain this submergence by a cumulative effect of the relative sea level change caused by the regional glacio hydro isostatic signal active since the end of the last glacial maximum and the local volcano tectonic land subsidence finally a total subsidence rate of 2 05 0 1 mm yr 1 with a volcano tectonic contribution of 1 43 0 1 mm yr 1 for the last 2 ka bp is inferred from the comparison against the latest predicted sea level curve for the southern tyrrhenian sea suggesting new evaluations of the volcano tectonic hazard for this area of the aeolian islands

the papal front of 3 may 1987 a remarkable example of frontogenesis near the alps all available routinely collected surface data are used to document the development of the papal front which crossed southern germany on 3 may 1987 causing casualities and damage objective analyses on isentropic surfaces initialized with the european aerological data indicate that the development of the violent mesoscale front which exhibited squall line characteristics began when a distinct mid troposopheric anomaly of potential vorticity reached the north western rim of the alpine arc the forced uplift ahead of the associated shortwave trough combined with ageostrophic motions due to a jet streak at higher levels apparently provided a trigger for deep convection as was observed over the alpine foreland numerical simulations with a dry hydrostatic model indicate the relative importance of the synoptic scale forcing and the alpine orography for the generation of the papal front a westerly orographic jet over the foreland below crest height only develops in the simulation with full alps and is corroborated by the few mountain wind observations that are available a comparison with studies of frontal propagation along other mountain ranges reveals that the routine network in the alpine region and its surroundings is at least of similar density but so far hardly used for frontal case studies it is concluded that a series of routine data case studies could help to determine the variability of frontal progression along the alps and thus provide guidance when assessing the significance of single events particularly those sampled during special observation programmes

age and petrology of the late pleistocene brown tuffs on lipari italy late pleistocene volcanic products on lipari consist mainly of pyroclastic surge deposits monte guardia sequence and fine grained brown tuffs radiometric age determination on carbon from thin soils at the top of the tuffs indicate that they have several ages of emplacement ranging from more than 35 000 to 16 800 years ago chemical and microprobe data on glass and mineral fragments from these tuffs show that they belong to a shoshonite or high k series this composition is compatible with an origin related to the magma system of vulcano but not with the magma system on lipari

volcanic history of lipari aeolian islands italy during the last 10 000 years abstract examination of the volcanic stratigraphy of deposits younger than 10 000 years on lipari indicates four principal periods of volcanic activity related to specific centers the products from each different volcanic center are defined as volcano stratigraphic unit vsu from the oldest these are the canneto dentro gabellotto fiume bianco forgia vecchia and monte pilato rocche rosse vsus the study of textures and dispersal of the deposits permitted the vents to be localized and the recent volcanic history of lipari to be reconstructed the oldest event formed a small explosion breccia cone with a final obsidian lava in the canneto dentro area immediately afterward a complex series of explosions produced the widespread dry surge deposits of the gabellotto fiume bianco sequence this activity ended with the extrusion of a domical lava flow the renewal of activity occurred in the pirrera area with an explosive eruption that produced explosion breccia deposits the last eruptions from this vent were coeval with the first eruption of m pilato the rim of the explosion breccia cone was partially destroyed by the forgia vecchia lava flow m pilato cone grew in a very short period of time due to a continuous swarm of explosive events after a short repose time a series of more energetic and superficial explosions occurred through a vent slightly to the south the extrusion of the rocche rosse lava flow about 729 a d ended this cycle of activity all the volcanic centers follow a quite similar stochastic pattern starting with a fall or surge eruption and ending with effusion of viscous rhyolitic lavas the four centers are aligned along either nw se or ne sw fault systems according to the structural pattern of the island they can be placed into two groups the canneto dentro gabellotto centers and the forgia vecchia m pilato centers a long quiescence 3 500 years separates the activity of these two groups while inside of each the activities were nearly contemporaneous or in rapid succession

deformation of the 125 ka marine terrace in italy tectonic implications in peninsular italy marine terraces and shorelines created during oxygenisotope substage 5e known historically as the tyrrhenian highstand provide a reliable and homogeneous datum of vertical motions during the past 125 000 years published accounts of 121 locations on the tyrrhenian inner edge were reinterpreted and used to calculate both local and regional uplift rates the data show arching of southern italy between the tyrrhenian and the adriatic coasts and of the calabrian arc between the sangineto and the longi taormina tectonic lineaments at rates of up to 1 2 mm yr for the past 125 ka they also suggest that the present configuration of the southern apennines is the product of post early pleistocene regional uplift superimposed on tortonian to early pleistocene thrusting uplift patterns are characterised by different wavelength in different geodynamic settings suggesting a close link with the depth of the causative tectonic sources

evolution of the southern tyrrhenian slab tear and active tectonics along the western edge of the tyrrhenian subducted slab abstract the evolution of the southern tyrrhenian subduction has been possibly controlled by distinct episodes of slab break off as indicated by a critical review of the geological literature and by the analysis of purposely acquired multichannel seismic profiles within the proposed interpretation the first episode occurred from 8 5 to 4 0 ma and affected the segment of the slab located in the sardinia channel causing the abandonment of the adventure thrust front in western sicily the second episode occurred between 2 5 and 1 6 ma affecting the segment of slab located north of sicily and was preceeded by rifting in the strait of sicily the space and time location of these episodes appear controlled by discontinuities pre existing within the subducted african plate that trend at high angle to the advancing subduction front these discontinuities delimit segment of subducted slab that can be affected by slab break off and can act as wayouts for magma and mantle derived he the major of these discontinuities the malta escarpment has been reactivated in the quaternary as a trench perpendicular tear step faults ultimately the hierarchy in strength of these trench perpendicular features could have affected the timing and amount of trench retreat and backarc opening

late quaternary relative sea level changes and vertical movements at lipari aeolian islands indicators of former sea levels are recognised on the emergent portion of lipari aeolian islands they correlate with three raised shorelines located at elevations of 43 45 m above present sea level i 23 27 m ii and about 12 m iii according to stratigraphical constraints these shorelines correlate with the sea level highstands corresponding to marine oxygen isotope substages 5e 124 ka 5c 100 ka and 5a 81 ka respectively the correlation of the shoreline i with substage 5e is supported by a u th age 119 6 ka obtained from corals chronological and height data relevant to the fossil shorelines indicate that lipari was affected by uplift with an average rate of 0 34 mm yr 1 during the past 125 ka this uplift rate accords with the average uplift rates obtained during the same time period from the nearby islands of filicudi 0 31 mm yr 1 and salina 0 36 mm yr 1 combined these data suggest a similar uplift trend related to regional tectonic processes in contrast to the long term uplift a localised submergence trend documented especially for the last century affects the eastern coast of lipari this subsidence is related to neo and or volcano tectonic processes copyright 2002 john wiley sons ltd

temporal evolution of a three component system the island of lipari aeolian arc southern italy the volcanic products from lipari define an evolutionary trend with a high gradient of k enrichment similar to the calc alkaline to potassic volcanism of other islands in the aeolian arc stratigraphic reconstruction of the island based on field and geochronological data indicate that the volcanic activity can be subdivided in two stages the first stage from 223 to 42 ka consists of six eruptive cycles and is characterized by basalts and basalt andesites showing progressive increase in both sio2 and k2o contents with time the second stage consists of four cycles erupted since 42 ka and is marked by an apparent rejuvenation of the geochemical system with the appearance of the first rhyolitic products fractional crystallization assimilation and mixing models suggest that the geochemistry of lipari volcanism evolved with time by a complex interplay between two mantle derived components one sub alkaline and the other alkaline in addition to crustal melts and or crustally derived materials a petrogenetic model in which fractional crystallization was subordinate to mixing best fits the geochemical data and petrographic observations of macro and microscopic features melts from the crustal and mantle end members are almost always present in the system but the relative proportions appear to vary with time the sub alkaline mantle component source of tyrrhenian tholeiites is an important contributor to the early evolution of the volcanism in lipari input from the alkaline mantle component source of the roman comagmatic province increases with time and the crustal component becomes dominant in the later activity the preferred petrogenetic model for the temporal evolution of the volcanic system in lipari involves melting initially caused by an increase in the thermal input related to the opening of the tyrrhenian sea and or to subduction processes the quick rise of the isotherms and almost contemporaneous melting of source materials with different compositions favored complex mixing during ascent of the melts

comment to volcanic geomorphology and tectonics of the aeolian archipelago southern italy based on integrated dem data by favalli et al bull volcanol 68 157 170 2005 doi 10 1007 s00445 005 0429 3

airborne doppler observations of a landfalling cold front upstream of steep coastal orography abstract this study uses airborne doppler radar observations to describe the mesoscale structure and evolution of a cold frontal system as it made landfall on the mountainous coast of oregon and northern california on 1 december 1995 during the coastal observations and simulations with topography experiment this section of coastline constitutes a steep approximately two dimensional north south oriented orographic barrier the front exhibited a northeast southwest orientation and thus intersected the axis of high terrain at an acute angle the along barrier pressure gradient and low level winds increased with time along the coastal zone and reached a maximum as the front made landfall stably stratified prefrontal flow was strongly blocked by the orography resulting in a confluent transition from pervasive southwesterly winds offshore to a narrow zone of accelerated south southwesterly flow near the coast where wind speeds approached 30 m s 1 at a height of 750 m above mean sea level postfrontal flow

meteorological tower measurements of a surface cold front abstract measurements from the boulder atmospheric observatory meteorological research tower are used to describe the structure and physical processes of a strong surface cold front analysis reveals that the horizontal gradients in temperature and wind velocity at the front are concentrated within a 200 m distance and measured vertical velocities exceed 5 m s 1 at the leading edge of the front calculations with the miller frontogenesis equation show the magnitude and relative importance of cross frontal confluence versus differential vertical motion tilting in forcing frontogenesis

pattern of deformation around the central aeolian islands evidence from multichannel seismics and gps data the tectonics of the central aeolian islands which are located within the tyrrhenian backarc basin has been investigated through a marine seismic reflection survey we find that compressional structures dominate around the islands whereas extensional faults occur only to the north of salina and filicudi towards the marsili basin this pattern of deformation although different from previously reported is in agreement with the strain field and stress regime obtained from gps measurements and seismological data age constraints suggest that contractional deformation was active since middle pleistocene being coeval with the building of the volcanic edifices of the aeolian islands and is superimposed on pre existing extensional deformation compressional and extensional regimes therefore can coexist within a backarc setting seismic profiles show that the tindari letojanni fault considered as a major tectonic element does not extend to the north towards the island of vulcano as a throughgoing fault rather deformation is accommodated in a broader belt displaying greater structural complexity

observations of nonclassical frontal propagation and frontally forced gravity waves adjacent to steep topography through the integrated analysis of remote sensing and in situ data taken along the front range of colorado this study describes the interactions that occurred between a leeside arctic front and topographically modulated flows these interactions resulted in nonclassical frontal behavior and structure across northeastern colorado the shallow arctic front initially advanced southwestward toward the front range foothills before retreating eastward then a secondary surge of arctic air migrated westward into the foothills during its initial southwestward advance the front exhibited obstacle like density current characteristics its initial advance was interrupted by strong downslope northwesterly flow associated with a high amplitude mountain wave downstream of the continental divide and by a temporal decrease in the density contrast across the front due to diurnal heating in the cold air and weak cold advection in the warm air the direction and depth of flow within the arctic air also influenced the frontal propagation the shallow obstacle like front actively generated both vertically propagating and vertically trapped gravity waves as it advanced into the downslope northwesterly flow resulting in midtropospheric lenticular wave clouds aloft that tracked with the front because the front entered a region where strong downslope winds and mountain waves extended downstream over the high plains the wave field in northeastern colorado included both frontally forced and true mountain forced gravity waves a sequence of scorer parameter profiles calculated from hourly observations reveals a sharp contrast between the prefrontal and postfrontal wave environments consequently analytic resonant wave mode calculations based on the scorer parameter profiles reveal that the waves supported in the postfrontal regime differed markedly from those supported in the prefrontal environment this result is consistent with wind profiler observations that showed the amplitude of vertical motions decreasing substantially through 16 km above mean sea level msl after the shallow frontal passage

airborne dual doppler observations of an intense frontal system approaching the pacific northwest coast airborne doppler radar data collected off the pacific northwest coast by a noaa wp 3d orion aircraft over an 8 h period on 8 december 1993 during the coastal observations and simulations with topography experiment reveal the mesoscale structure of an intense frontal system while it was well offshore and as it approached within 20 km of the oregon coastline during the offshore stage a portion of the narrow coldfrontal rainband was characterized by deep convective cores pseudo dual doppler analyses characterize the kinematic and precipitation structure of the deep convection pseudo dual doppler analyses describe the subsequent evolution of the narrow cold frontal rainband as it approached to within 20 km of the oregon coast deformation of the frontal zone appeared to cause the dissipation of one of three precipitation cores contained within the dual doppler area the precipitation cores and the strong convergence zone associated with the front conformed to some degree to the shape of the coastline near cape blanco oregon as the front neared the coast changes in the prefrontal flow that occurred as the front approached the coast were qualitatively consistent with theoretical and numerical studies of upstream orographic influence comparison of pseudo dual doppler derived velocity profiles with idealized numerical model calculations suggests that the nearshore evolution of the frontal rainband was significantly affected by an upstream influence of the coastal orography

a strontium isotopic study of newberry volcano central oregon structural and thermal implications abstract ratios of 87 sr 86 sr were determined in twenty seven basaltic rocks from newberry these ratios range from 0 70330 to 0 70414 most fall between 0 7035 and 0 7038 covariance of al 2 o 3 feo ratio tio 2 content and th content with 87 sr 86 sr suggests that some isotopic ratios reflect shallow crustal contamination but the data also suggest that two mantle sources a prominent one at 0 7036 and a less prominent one at 0 7033 or less are represented the hypothesis of crustal contamination is supported by variations in 87 sr 86 sr ratios with locations of the vents from which these rocks erupted sr tends to be more radiogenic in rocks from vents either close to a silicic complex such as the caldera of the volcano or the amota butte sugar pine ridge complex or close to axes of the fault zones that underlie the edifice presumably local heating of the upper crust facilitates contamination of basaltic magma rising through it

numerical study of convection observed during the winter monsoon experiment using a mesoscale two dimensional model abstract a two dimensional version of the pennsylvania state university mesoscale model has been applied to winter monsoon experiment data in order to simulate the diurnally occurring convection observed over the south china sea the domain includes a representation of part of borneo as well as the sea so that the model can simulate the initiation of convection also included in the model are parameterizations of mesoscale ice phase and moisture processes and longwave and shortwave radiation with a diurnal cycle this allows use of the model to test the relative importance of various heating mechanisms to the stratiform cloud deck which typically occupies several hundred kilometers of the domain frank and cohen s cumulus parameterization scheme is employed to represent vital unresolved vertical transports in the convective area the major conclusions are ice phase processes are important in determining the level of maximum large scale heating and vertical motion because there is a strong anvil componen

flooding scenarios due to land subsidence and sea level rise a case study for lipari island italy archaeological and instrumental data indicate that the southern sector of the volcanic island of lipari has been subsiding for the last 2100 years due to isostatic and tectonic factors at variable rates of up to 11 mm yr based on this data a detailed marine flooding scenario for 2100 a d is provided for the bay of marina lunga in the eastern part of the island from i an ultra high resolution digital terrain and marine model dtmm generated from multibeam bathymetry mb and unmanned aerial vehicles uav ii the rate of land subsidence from gps data and iii the regional sea level projections of the international panel on climate change ipcc when land subsidence is considered the upper bound of sea level rise is estimated at 1 36 m and 1 60 m for rcp4 5 and rcp8 5 climate change scenarios respectively here we show the expected impact of marine flooding at lipari for the next 85 years and discuss the hazard implications for the population living along the shore this article is protected by copyright all rights reserved

numerical simulations of a landfalling cold front observed during coast rapid evolution and responsible mechanisms abstract this paper identifies mechanisms that led to the observed rapid evolution of a landfalling weak cold front along the steep mountainous northern california coast on 1 december 1995 this event was simulated down to 3 km horizontal grid spacing using the pennsylvania state university ncar mesoscale model version 5 mm5 the mm5 simulation reproduced the basic features such as the timing location and orientation of the cold front and associated precipitation evolution as well as the tendency for enhanced precipitation to extend 50 100 km upwind of the coastal barrier with the heaviest amounts occurring over the windward slopes 0 20 km inland locally however the model underestimated the magnitude of the prefrontal terrain enhanced flow by as much as 30 since the simulated low level static stability was weaker than observed the mm5 simulations illustrate the complex thermal wind and precipitation structures in the coastal zone upstream flow blocking by the steep coastal terrain led to

reconciliation of late quaternary sea levels derived from coral terraces at huon peninsula with deep sea oxygen isotope records a major discrepancy between the late quaternary sea level changes derived from raised coral reef terraces at the huon peninsula in papua new guinea and from oxygen isotopes in deep sea cores is resolved the two methods agree closely from 120 ka to 80 ka and from 20 ka to 0 ka ka 1000 yr before present but between 70 and 30 ka the isotopic sea levels are 20 40 m lower than the huon peninsula sea levels derived in earlier studies new high precision u series age measurements and revised stratigraphic data for huon peninsula terraces aged between 30 and 70 ka now give similar sea levels to those based on deep sea oxygen isotope data planktonic and benthic 18o data using the sea level and deep sea isotopic data oxygen isotope ratios are calculated for the northern continental ice sheets through the last glacial cycle and are consistent with results from greenland ice cores the record of ice volume changes through the last glacial cycle now appears to be reasonably complete