migrating and nonmigrating semidiurnal tides in the upper atmosphere excited by tropospheric latent heat release migrating and nonmigrating semidiurnal tides

critical slip surface and landslide volume of a soil slope under random earthquake ground motions finding the critical slip surface and estimating the landslide volume are of primary importance for slope seismic design however this may be difficult due to the uncertainty of ground motions to address this problem a new method for calculating uncertainties is recommended in this paper especially for the critical slip surface and landslide volume under random earthquake ground motions firstly a series of intensity frequency nonstationary random earthquake ground motions were generated based on an improved orthogonal expansion method a given number of potential slip surfaces were set in a soil slope subsequently the factor of safety fos of each slip surface for all ground motions was calculated and the minimum fos curves were obtained it was found that the critical slip surfaces and failure times are uncertain under different earthquakes the monte carlo method was used to verify the accuracy of probability density evolution method pdem and the results of the pdem and the monte carlo method are consistent meaning that the pedm has higher computational efficiency moreover the distributions of earthquake triggered landslide volume and landslide depth were analyzed by considering equivalent extreme events both landslide volume and depth exhibit a normal distribution for a homogeneous soil slope the framework of this study is meaningful for slope seismic design in engineering for example the location of critical slip surface can be used for slope reinforcement and the distribution of sliding volume can be used for disaster assessment

observations of ionospheric heating during the passage of solar coronal hole fast streams 1 using ionospheric temperature measurements made continuously by the poker flat incoherent scatter radar pfisr and eiscat svalbard radar esr during the international polar year ipy we provide evidence for directly driven ionospheric heating associated with the solar wind corotating interaction region cir both esr and pfisr operated almost continuously during the ipy which began on 1 march 2007 during this period 55 cir events occurred and when isr observations were available during these events ionospheric heating was observed this study is the first comprehensive observation of ionospheric heating by cirs demonstrated through case study comparisons and statistically over the 1 year ipy period these multiple day heating events are present in both the auroral and polar regions the quantitative one to one correlation between ace cir observations and isr ionosphere observations leads to a database that will enable the ionospheric heating efficiency of cir events to be determined

effects of near fault seismic loadings on run out of large scale landslide a case study this study presents the run out analysis of the daguangbao landslides subjected to near fault multi direction earthquake forces using discontinuous deformation analysis dda the daguangbao landslide is the largest landslide induced by the 2008 wenchuan earthquake in order to investigate the effects of near fault seismic force on landslide run out kinematic behavior of sliding mass is simulated by a dynamic discrete numerical analysis method called dda in this simulation based on the shape of failure surface and the feature of slope geology the whole slope is divided into three parts base block upper sliding mass and lower sliding mass then two sliding masses are divided into the smaller discrete deformable blocks based on pre existing discontinuities size effect of the huge landslide is also considered baseline corrected real horizontal and vertical ground motions are taken as volume force acting to the base block the results show that seismic force has a significant influence on the landslide progression sliding distance and shape of post failure results of the horizontal and vertical situation are in good agreement with those obtained from post earthquake field investigation remote sensing image and description from the survivors

the arcuate shape of the umbria marche sabina apennines central italy abstract the umbria marche belt constitutes the most southern and external portion of the northern apennine arc typically convex to the northeast within this the central part the umbria marche sabina apennines is the most elevated and is characterized by a locally more pronounced curvature the umbria marche belt is a thrust belt built mainly by thrust faults affecting a multilayer sedimentary series characterized by levels with markedly different competence the main thrust the m sibillini thrust produced the tectonic superposition of the umbria marche sabina apennines over the most external units represented by the lazio abruzzi platform to the south and the marche abruzzi domain to the north farther north it joins the thrusts buried under the po plain the most important of the more internal thrusts is that of the valnerina the pronounced local curvature of the umbria marche sabina apennines may be due to accentuation of an original arcuate shape this accentuation is probably caused by differential displacement along the two main thrusts during the initial stage of the evolution of the belt late messinian early pliocene at that time this displacement was more important in the northern part where the thrust fronts show a nw se trend than in the southern portion where they are n s trending on account of the lazio abruzzi carbonate platform which perhaps represented a local obstacle to thrusting as for the initial curvature we think that this is determined by older discontinuities which controlled thrust development the final arcuate shape was not substantially changed during the subsequent compressional history of the belt early pliocene middle pliocene

distribution pattern of earthquake induced landslides triggered by the 12 may 2008 wenchuan earthquake abstract this paper presents the preliminary results of an extensive study of the mapping the distribution of landslides triggered by the wenchuan earthquake in sichuan province china on 12 may 2008 an extensive landslide interpretation was carried out using a large set of optical high resolution satellite images e g aster alos cartosat 1 spot 5 and ikonos as well as air photos for both the pre and post earthquake situation landslide scarps were mapped as points using multi temporal visual image interpretation taking into account shape tone texture pattern elevation and ridge and valley orientation nearly 60 000 individual landslide scarps were mapped the landslide distribution map was compared with the inventory map that was prepared directly after the earthquake which contains about 11 000 individual landslide points through the calculation of normalized landslide isopleths maps remarkable differences were observed as the earlier inventory mapping did not consider the pre earthquake situation and did not consider all individual landslides as part of the landslide inventory landslides were identified that had blocked the drainage and had formed landslide dams the landslide distribution was compared with a number of aspects such as the seismic parameters distance to epicenter distance to fault rupture co seismic fault geometry and co seismic slip distribution and geology the most remarkable correlation found was with the co seismic slip distribution and the fault geometry landslide distribution in the section of the fault that had mainly a thrust component with low angle fault plane was found to be much higher than the sections that had steeper fault angles and a major strike slip component

empirical models of storm time equatorial zonal electric fields ionospheric plasma drifts often show highly complex and variable signatures during geomagnetically active periods due to the effects of different disturbance processes we describe initially a methodology for the study of storm time dependent ionospheric electric fields we present empirical models of equatorial disturbance zonal electric fields obtained using extensive f region vertical plasma drift measurements from the jicamarca observatory and auroral electrojet indices these models determine the plasma drift perturbations due to the combined effects of short lived prompt penetration and longer lasting disturbance dynamo electric fields we show that the prompt penetration drifts obtained from a high time resolution empirical model are in excellent agreement with results from the rice convection model for comparable changes in the polar cap potential drop we also present several case studies comparing observations with results obtained by adding model disturbance drifts and season and solar cycle dependent average quiet time drift patterns when the disturbance drifts are largely due to changes in magnetospheric convection and to disturbance dynamo effects the measured and modeled drift velocities are generally in good agreement however our results indicate that the equatorial disturbance electric field pattern can be strongly affected by variations in the shielding efficiency and in the high latitude potential and energy deposition patterns which are not accounted for in the model these case studies and earlier results also suggest the possible importance of additional sources of plasmaspheric disturbance electric fields

coupling basin infill history and mammal biochronology in a pleistocene intramontane basin the case of western l aquila basin central apennines italy the western l aquila basin recorded in quaternary times two well distinguished phases of intramontane basin fill concomitant with uplift of central apennines and characterized by diverse large mammal assemblages the first phase was dominated by alluvial fan and lacustrine palustrine sedimentation respectively gelasian and calabrian in age that took place within an internally drained fault controlled hydrographic system a late villafranchian earliest galerian large mammal assemblage approximately 1 3e1 1 ma pertains to this phase and includes mammuthus meridionalis stephanorhinus etruscus and the large cervid arvernoceros aff a giulii the second phase of filling middle pleistocene to holocene in age is dominated by fluvial sedimentation which is related to a through going fluvial system developed after the emptying of the former lake a middle galerian large mammal assemblage approximately 600 ka comes from the oldest deposits of this phase biochronological data help date steps of geological and morphological evolution in an intramontane setting and permit to temporally constrain the major change in local hydrography and sedimentation at the early middle pleistocene transition this change was likely forced by an increment of uplift rates which is well recorded along the axial range and peripheral belts of the apennines 2011 elsevier ltd and inqua

multisatellite observations of an intensified equatorial ionization anomaly in relation to the northern sumatra earthquake of march 2005 here we report multisatellite observations of ionospheric disturbances in relation to the occurrence of the m8 7 northern sumatra earthquake of 28 march 2005 the demeter detection of electro magnetic emissions transmitted from earthquake regions and champ challenging minisatellite payload satellite data were investigated to find possible precursory and postevent phenomena it was found that eia equatorial ionization anomaly strength expressed in the apex height derived from the champ plasma density profile was intensified along the orbits whose longitudes were close to the epicenter within about a week before and after occurrence of the earthquake increases in electron and o density along the orbits close to the epicenter were also observed in the demeter measurements the normalized equatorial plasma density derived from the demeter measurements showed intensification about a week before and after the earthquake reaching maximum the day after the shock and afterward disappearing in addition similar behavior of the eia enhancements related to the m8 0 pisco earthquake of 15 august 2007 was observed surveys of space weather and geomagnetic activities excluded the possibility that these fluctuations were caused by changes in space weather or by a geomagnetic storm statistical analyses of the longitudinal variation revealed that the eia was enhanced in the west of the epicenter and reduced in the east of the epicenter and this fits the increased conductivity model based on these observations we proposed a revised view of seismo ionospheric coupling in the region of the geomagnetic equator to explain the eia features observed in this study

microtremor recordings in northern mississippi abstract this paper presents the results of 305 single point microtremor recordings covering northern mississippi that is situated within the upper mississippi embayment area both long and short term recordings were obtained by a le 3d 20s seismometer over a large network of points where the unconsolidated sediment thickness ust varies from zero to 1400 m applying the nakamura method the recordings were processed to determine predominant frequency f0 and its relation to ust initial results of wind influence on the frequency spectra particularly in low frequency band 0 05 0 2 hz and dominant vibration direction are also presented it is shown that analysis of systematic microtremor recordings can provide a stable and reliable estimation of the predominant frequency from which estimates of average shear wave velocity of overall sediment profile can be derived predominant frequency and average shear wave velocity is reasonably well correlated with ust wind and human activities are found to produce peaks over the low frequency band

longitudinal variations of positive dayside ionospheric storms related to recurrent geomagnetic storms 1 we have performed an analysis of case events and statistics of positive ionospheric storms in the dayside region of the equatorial ionization anomaly during recurrent geomagnetic storms rgss which dominate in geomagnetic and ionospheric conditions on the declining phase of solar activity in 2004 to 2008 it is shown that total electron content tec has a tendency to minimize before the beginning of rgss and to peak 3 to 4 days after i e on the rgs recovery phase produced by high intensity long duration continuous auroral activity the maximum of tec coincides with the maximum of solar wind velocity within high speed solar wind streams an analysis of electron content vertical profiles derived from two independent methods using ionosondes and constellation observing system for meteorology ionosphere and climate formosa satellite mission 3 radio occultation showed that in the maximum of an ionospheric storm on 28 march 2008 the f2 layer thickens nmf2 increases by 50 and hmf2 elevates by a few tens of kilometers the response of positive ionospheric storms to solar heliospheric and geomagnetic drivers reveals a prominent longitudinal asymmetry in the longitudinal range from 90 to 90 the solar illumination plays a major role and in the range from 90 to 120 the influence of heliospheric and geomagnetic drivers becomes significant the highest correlations of the tec enhancements with the heliospheric and geomagnetic drivers were found during december february r increased from 0 3 to 0 5 we speculate that the dynamics controlling this might result from an effect of solar zenith angle storm time effects of thermospheric o n2 enhancement and penetrating electric fields of interplanetary and magnetospheric origin

paleomagnetic research on black sea quaternary sediments abstract the paper reports the first paleomagnetic study of a black sea quaternary sediment core made by a bulgarian research group the experimental results show an important difference in magnetic behaviour between the samples from the holocene part and those from the pleistocene part of the core suggestions are made for the character of the remanent magnetization and the main carriers of it the presence of greigite fe 3 s 4 and pyrite fes 2 is discussed a rough correlation is established between the variation of inclination for the holocene part of the sediment and for the bulgarian archeomagnetic curve on the basis of the comparison of inclination data obtained from the pleistocene part of the core and previously studied black sea core related to the absolute time scale it is suggested that the lower boundary of the pleistocene part is 16000 years old bp

large and small mammal distribution patterns and chronostratigraphic boundaries from the late pliocene to the middle pleistocene of the italian peninsula abstract over the last 50 years the studies on terrestrial mammals of the italian peninsula have provided a large volume of data and a more detailed knowledge of faunal events during the late pliocene and quaternary moreover geological sedimentological palynological and magnetostratigraphical investigations on the pliocene pleistocene continental sedimentary basins have yielded the possibility of a detailed calibration of the faunal successions thus palaeontologists have been able to reconstruct faunal sequences and to propose biochronological scales based on large and small mammals respectively in the present contribution an integration of the two biochronological scales is proposed and the successions of bioevents are carefully compared this integrated approach allows the constraint of the sequence of large and small mammal events in a more reliable way and therefore it results in a more detailed and consistent chronological use of mammalian assemblages particular attention is paid to the faunal changes that correspond to the middle late pliocene 2 6 ma pliocene pleistocene 1 8 ma and early middle pleistocene gauss matuyama transition chronostratigraphical boundaries

magnetostratigraphic dating of an intensification of glacial activity in the southern italian alps during marine isotope stage 22 abstract we applied magnetostratigraphy and mammal biostratigraphy to date climate sensitive pollen cycles and lithostratigraphic units of the pliocene pleistocene leffe sedimentary succession from the southern alps italy the leffe section was correlated to additional sections casnigo fornaci di ranica and pianengo to construct a stratigraphic network along a common fluviatile system the serio river sourced in the southern alps and flowing southward into the po river basin we obtained a coherent scenario of climate variability for the last 2 myr at leffe lacustrine deposition commenced during the olduvai normal subchron 1 94 1 78 ma and lasted up to a chronologic level compatible with marine isotope stage mis 22 0 87 ma pollen analysis revealed that climate varied cyclically from warm temperate to cool during this time interval but never as cold as during glacial intervals at around mis 22 climate cooled globally gravels attributed to high energy braided river systems fed locally by alluvial fans prograded from the serio river catchment area over the leffe basin and toward the po plain in response to a generalized event of vegetation withdrawal and enhanced physical erosion at this time alpine valley glaciers reached their first maximum southward expansion with glacier fronts located at only 5 km upstream from leffe

pleistocene debris flow deposition of the hippopotamus bearing collecurti bonebed macerata central italy taphonomic and paleoenvironmental analysis abstract an integrated taphonomic sedimentological study provides insight into the origin preservation biases and paleobiological significance of the latest early earliest middle pleistocene bonebed of collecurti near colfiorito macerata central italy which represents an important benchmark in the european biochronological scale sedimentological evidence indicates that the bonebed is hosted in a debris flow deposit which was emplaced in a shallow lacustrine setting geologic and geomorphic controls on sedimentation in the intermontane colfiorito basin provided an ideal setting for the development of cohesive mass flows due to high relief and poorly integrated catchments along the basin margin and the abundance of detrital fines yielded by mesozoic sedimentary rocks of the local basement the fossil assemblage includes 496 bones with a minimum of 24 individuals representing 9 species and 8 genera dominated by hippopotamus antiquus the hippopotamus remains include partially articulated carcass parts as well as closely associated elements few disarticulated elements which are bones that can be more easily transported hydraulically were involved in pre debris flow winnowing and sorting and then entrained by the debris flows in nearby uplands transported a short distance down into a shallow pond or lake margin where the flow buried hippopotamus carcasses that had accumulated in the pond lake the hippopotamus carcasses were in an advanced state of decomposition when the debris flow entrained them their bones show no evidence of weathering trampling scavenging sorting or transportation prior to debris flow reworking which indicates that the animals were probably lying on the bottom of the pond where they lived or were already partially buried in mud previous palynological investigations have shown that the strata of interest at collecurti were deposited during a climatic trend toward ever increasing cooler conditions the low richness of the fauna confirms long exposure to harsh climatic and environmental conditions two are the plausible causes of the death of the collecurti animals i e severe cold and or drought taphonomic attributes rule out drought indicating that the assemblage accumulated in a short time as the result of a mass mortality event possibly due to a cold snap there are no other reported examples of quaternary debris flow hosted bonebeds in europe probably because this agent of taphonomic accumulation is rarely investigated in high energy paleogeomorphic settings it is likely that more such sedimentary events took place in the area and that similar fossil sites await to be discovered

a petromagnetic study of miocene rocks bearing micro organic material and the magnetic mineral greigite sokolov and cheb basins czechoslovakia abstract the middle miocene sediments of the cypris series from the sokolov and cheb brown coal basins western bohemia were subjected to petromagnetic investigation during the laboratory thermal treatment at a temperature of 350 400 c the samples rich in micro organic material changed into carbonified samples which exhibited similar physical and technological properties to coal samples collected from the underlying coal seam the experimental results may have a bearing on several problems concerning the origin of fossil fuels and highlight specific rock properties which may have potential for identifying the micro organic content a strongly magnetic mineral greigite fe 3 s 4 was identified in magnetic zones above the coal seam the authigenic mineral greigite occurs in strata of greater thickness and it was found that a reducing environment generated by the presence of organic matter was required for the formation of the greigite metastable properties and the low coercivity spectra of this mineral are adverse for palaeomagnetic investigations

landslide seismic signal recognition and mobility for an earthquake induced rockslide in tsaoling taiwan abstract landslide seismic signal processing and the newmark s sliding block analysis are used in this research to analyze the initiation time and mobility of the tsaoling rockslide triggered by the 1999 chi chi earthquake in central taiwan a new technique the time frequency spectrum analysis is employed to identify the rockslide initiation and landing times from four real time seismic records of strong ground motion stations the results suggest that higher frequencies ranging from 30 to 70 hz correspond to the rockslide initiation and sliding process which are opposed to the low signal frequency of earthquake the landslide began at 32 5 s the sliding block sped up at 37 5 s and impacted on the opposite riverbank at 76 s on the seismic time record the mobile scenario of tsaoling rockslide induced by chi chi earthquake is simulated using newmark s sliding block analysis the maximum sliding velocity reaches approximately 75 1 m s despite being a simple conceptual model the newmark s sliding block analysis provides consistent results with the real time seismic signal analysis and details of the rockslide kinematics

palaeoenvironmental and climatic inferences from the late early pleistocene lacustrine deposits in the eastern tiberino basin central italy within the neogene quaternary evolution of the mediterranean intermountain basins the eastern tiberino basin provides new multifaceted chronological biostratigraphic palaeoecological and palaeoenvironmental information appreciably improving the knowledge of palaeoenvironmental and climate conditions during the middle late matuyama chron late early pleistocene shallow to relatively deep lacustrine deposits and alluvial plain deposits magnetostratigraphically calibrated hold malacofaunas ostracofaunas and carpological remains as well as a pollen record palaeocarpological remains widely originated from the local azonal vegetation of waterlogged environments nonetheless some taxa show transitional morphology between possibly extinct pliocene pleistocene forms and living taxa the pollen record highlights a conifer dominated forest phase indicating a temperate wet interglacial period well aligned inside the schemes for the same latitudinal band the abundance of tree taxa currently absent from the italian peninsula points to pre jaramillo late early pleistocene biostratigraphical characters here compared to other sections from central italy and contributes to a better definition of modes and timing of their disappearance in southern europe malacofaunas and ostracods still with late early pleistocene features together with charophyte mark repeated fluctuations in energy temperature and chemical composition of water the overall record identifies an incipient diachronous cooling trend for the first time recognized in southern europe

quiet time equatorial f region vertical plasma drift model derived from rocsat 1 observations 1 we have used five years of measurements on board the rocsat 1 satellite to develop a detailed quiet time global empirical model for equatorial f region vertical plasma drifts this model describes the local time seasonal and longitudinal dependence of the vertical drifts for an altitude of 600 km under moderate and high solar flux conditions the model results are in excellent agreement with measurements from the jicamarca radar and also from other ground based and in situ probes we show that the longitudinal dependence of the daytime and nighttime vertical drifts is much stronger than reported earlier especially during december and june solstice the late night downward drift velocities are larger in the eastern than in the western hemisphere at all seasons the morning and afternoon december solstice drifts have significantly different longitudinal dependence and the daytime upward drifts have strong wave number four signatures during equinox and june solstice the largest evening upward drifts occur during equinox and december solstice near the american sector the longitudinal variations of the evening prereversal velocity peaks during december and june solstice are anti correlated which further indicates the importance of conductivity effects on the electrodynamics of the equatorial ionosphere

landslide dam deformation analysis under aftershocks using large scale shaking table tests measured by videogrammetric technique abstract the ms 8 0 wenchuan earthquake triggered at least 257 landslide dams more than 849 aftershocks with magnitudes higher than ms 4 0 occurred after the wenchuan earthquake by 12 march 2012 shen et al 2013 which might largely influence the structure and soil properties of these dams this paper aims to study the dynamic deformation of landslide dams under aftershocks through larger scale shaking table tests videogrammetric technique was applied to measure the dynamic deformation of the model dams two groups of shaking table tests were conducted with two types of landslide dam materials one with quartz sands containing 10 kaolin dam i and the other with only quartz sands dam ii the dam deformation and its influencing factors were analyzed with the results measured by videogrammetric technique the deformations were generally higher on the surface of the dams either on the crest or on the both upstream and downstream slopes higher peak ground acceleration pga resulted in larger dam deformations due to higher seismic force the deformations under the combination of x and z directional shakings were larger than those under x directional shaking for sufficient vibratory compaction water rising led to the increase of dam deformations because that the water seepage reduced the effective soil stress especially reduced the matric suction the settlements of the dam composed of more fine particles were larger than that composed of large particle size because that the soil pores in the former were filled more sufficiently with fine particles the aftershocks may not directly trigger the failures of landslide dams but accelerate the overtopping failures by lowering the dam crest with settlement and cracking

response of high strength rock slope to seismic waves in a shaking table test studies on landslides by the 2008 wenchuan earthquake showed that the topography is of great importance in amplifying the seismic shaking the present study carried out experiments on rock slopes by means of a shaking table the recorded wenchuan earthquake waves are scaled to excite the model slopes measurements from accelerometers installed on free surface of the model slope simulating high strength rocks are analyzed with much effort on acceleration responses to both horizontal and vertical components of seismic shaking it is found that the amplification factor of peak horizontal acceleration pha is increasing with elevation of the model slope though the upper and lower halves of the slope exhibit different increasing patterns the amplification factor of peak vertical acceleration pva exhibits a lying s shaped changing trend with the elevation indicating attenuations of pvas at the toe and top of a slope in addition the xz direction shaking produces a horizontal and vertical response stronger than x direction and z direction shaking alone both pha and pva increase with the excitation intensity however the corresponding amplification factors generally decrease indicating the acceleration response of a slope weakens with the excitation intensity of shaking finally the statistic of ratio of pva to pha indicates that 85 of the slope height especially the upper middle part is likely subject to pvas greater than or equal to 2 3 of pha and 32 of the slope height to pvas greater than or equal to pha this indicates the nonignorable role of pva in responses of a slope to an earthquake and necessity of considering during design work

satellite studies of mid and low latitude ionospheric disturbance zonal plasma drifts we use low and mid latitude zonal ion drift observations from the de 2 satellite and auroral electrojet indices to study the temporal and latitudinal variations of f region perturbation drifts during magnetically disturbed conditions these perturbation drifts are driven by magnetospheric and ionospheric disturbance dynamo electric fields with time constants from less than one to several hours we determine initially the drift patterns due to the prompt penetration of magnetospheric electric fields and of longer lasting disturbances in this study we concentrate on the properties of the longer lasting perturbations which occur with latitude dependent time delays after enhancements in the high latitude ionospheric currents these perturbation drifts are predominantly westward at all latitudes with largest amplitudes in the midnight sector and smallest near noon the daily variation of these disturbance drifts derived from the satellite data is in good agreement with results from incoherent scatter radar observations our results indicate that these longer lasting perturbations are due to the combined effects of ionospheric disturbance dynamo electric fields and leakage of high latitude steady state electric fields to lower latitudes

high speed stream impacts on the equatorial ionization anomaly region during the deep solar minimum year 2008 1 to demonstrate high speed stream effects during the recent deep solar minimum year 2008 we have analyzed manually scaledfof2 and hmf2 at jicamarca and total electron content tec in the equatorial ionization anomaly eia region over the america longitudinal sector our results reveal that a prominent 9 day oscillation appears in the hmf2 and fof2 at the dip equator the 9 day oscillation amplitudes of fof2are not always positively correlated with tec in the equatorial ionosphere and they show nonlinear dependence on the intensity of geomagnetic disturbances with the outputs of fejer and scherliess s 1997 empirical model we found that this periodicity is also present in equatorial vertical drifts caused by disturbance dynamoelectric field ddef but absent in the drifts due to prompt penetration electric field ppef ddef effects on the equatorial periodic variations alone are not sufficient to explain the observed phenomena other mechanisms such as thermal expansion contraction and neutral composition changes are also the plausible causes of the periodic oscillation in the equatorial ionosphere further the complicated patterns appear in the 9 day band pass filtered tec perturbations in the eia region and they are quite different from the patterns of global coherent thermospheric oscillations triggered by high speed streams we also found that the latitudinal variations of band passed filtered tec present different behaviors involving tilt latitudinal configuration antiphased correlation between the crests and trough and south north asymmetry which vary as a function of season local time or even from event to event

a late early pleistocene pollen record from fontana ranuccio central italy a pollen record from a sediment core drilled underneath the acheulian site of fontana ranuccio provides new data on the vegetation characters in central italy during the late early pleistocene in a forest phase possibly corresponding to a substage of marine isotope stage 21 a number of tree taxa nowadays extinct in europe cathaya tsuga taxodium type carya and pterocarya are present at fontana ranuccio in a temperate phase characterised by dense forest conditions dominated by alnus and pterocarya the comparison of the fontana ranuccio record with other dated sites distributed along the italian peninsula indicates that the floristic and vegetational characters of the mid pleistocene revolution present a rather distinct succession of biostratigraphic events compared to other early pleistocene pollen records from southern europe the italian peninsula shows greater floristic similarities with the eastern mediterranean regions than with the iberian peninsula copyright 2011 john wiley sons ltd

simplified procedure for estimating earthquake induced deviatoric slope displacements a simplified semiempirical predictive relationship for estimating permanent displacements due to earthquake induced deviatoric deformations is presented it utilizes a nonlinear fully coupled stick slip sliding block model to capture the dynamic performance of an earth dam natural slope compacted earth fill or municipal solid waste landfill the primary source of uncertainty in assessing the likely performance of an earth waste system during an earthquake is the input ground motion hence a comprehensive database containing 688 recorded ground motions is used to compute seismic displacements a seismic displacement model is developed that captures the primary influence of the system s yield coefficient ky its initial fundamental period ts and the ground motion s spectral acceleration at a degraded period equal to 1 5 ts the model separates the probability of zero displacement i e 1 cm occurring from the distribution of nonzero displacement so that very low values of calculated

ground vibrations produced by rock motions and debris flows 1 in this study we compare ground vibrations generated by various rocks and debris flows at the same channel to explore the origin of ground vibrations caused by debris flows in field experiments we identified the ground vibrations caused by motions of individual rocks ground vibrations were detected by geophones and analyzed in the time frequency domains we found that ground vibrations caused by individual rocks were 10 150 hz and that larger stones generate ground vibrations with lower peak frequencies a sphere packing model of granular rocks was used to estimate the propagation speed of ground vibrations this was found to be underestimated when compared with our experimental data the signal decay rate was obtained under the assumption that ground vibrations propagate as exponentially attenuating cylindrical waves ground vibrations produced by a debris flow at ai yu zi creek nan tou taiwan on 2 july 2004 revealed that the debris flow forefront produced vibrations lower than 50 hz and ranged between 50 and 100 hz after the front had passed when the main front was closest to the sensor the frequency spectrum covered a wide range from 10 to 250 hz the mean velocity of the debris flow front was 13 3 m s frequencies of ground vibrations caused by individual rocks are within the frequency range of ground vibrations captured during the debris flow confirming that one of the main sources of ground vibration caused by debris flows is the interaction of rocks or boulders with the channel bed

magnetic properties and metastability of greigite smythite mineralization in brown coal basins of the krusne hory piedmont bohemia finely dispersed forms of greigite or greigite smythite mineralization were found in layers a hundred and more metres thick in the miocene strata of the krusne hory erzgebirge piedmont brown coal basins under laboratory thermal treatment a pronounced instability of greigite or greigite smythite mineralization was revealed by the magnetic parameters conditioned by mineralogical metastability thermal treatment in oxidation conditions caused the most pronounced changes in magnetic parameters in a temperature range of 320 380 c in which a laboratory process of self reversal of remanence was observed the products obtained during thermal treatment were identified with the aid of x ray diffractographs co radiation fe filter when they were heated to 250 c no substantial changes were found while at 300 c the intensities of greigite became weaker and pyrite and marcasite originated to its detriment hexagonal pyrrhotite was generated in addition to pyrite and marcasite a total decomposition of bisulphides took place at temperatures above 400 c accompanied by the formation of various modifications of fe2o3 until finally at higher temperatures only fe2o3 was formed laboratory tests suggested self reversal of remanence in relation to the formation of pyrrhotite so far greigite or greigite smythite mineralization has been proven to exist in the bohemian massif solely in connection with miocene rocks containing fossil micro organic matter products of thermal alteration pyrite marcasite pyrrhotite and fe2o3 or fe3o4 depending on redox conditions may be expected in rocks of similar genesis but partly or completely carbonified as a result of a process of pyrolysis of the micro organic matter

seasonal and longitudinal dependence of equatorial disturbance vertical plasma drifts 1 we used equatorial measurements from the rocsat 1 satellite to determine the seasonal and longitudinal dependent equatorial f region disturbance vertical plasma drifts following sudden increases in geomagnetic activity the prompt penetration vertical drifts are upward during the day and downward at night and have strong local time dependence at all seasons the largest prompt penetration drifts near dusk and dawn occur during june solstice the daytime disturbance dynamo drifts are small at all seasons they are downward near dusk with largest smallest values during equinox june solstice the nighttime drifts are upward with the largest magnitudes in the postmidnight sector during december solstice during equinox the downward disturbance dynamo drifts near sunset are largest in the eastern hemisphere while the late night upward drifts are largest in the western hemisphere the longitudinal dependence of the disturbance dynamo drifts is in good agreement with results from simulation studies

cesi an early middle pleistocene site in the colfiorito basin umbro marchean apennine central italy near the village of cesi at the head of the chienti river in the colfiorito basin umbro marchean apennines central italy fluvio lacustrine deposits have yielded mammal fossil remains the results of a multidisciplinary investigation indicate that the vertebrate bearing sediments date about 700 ka and accordingly provide a fossil assemblage for the middle late galerian palynological investigations carried out from sediments underlying the fossiliferous level suggest predominantly cold and dry conditions whereas the fauna suggests a slight climatic amelioration towards cool and moist conditions in the uppermost part of the sequence 1997 john wiley sons ltd

the colle curti mammal site in the colfiorito area umbria marchean apennine italy geomorphology stratigraphy paleomagnetism and palynology abstract an approximately 90 m thick sequence has been studied in the colle curti basin colfiorito area umbria marchean apennine it was deposited in a drainage system characterized by a mature landscape without a clear watershed separating the adriatic and tyrrhenian sides close to the end of the early pleistocene this landscape was dismembered by the activation of extensional faults linked to an uplifting of the chain that reached its greatest magnitude at the beginning of the middle pleistocene from a sedimentological point of view the sequence can be roughly divided into three parts with gravel deposition in a braidplain environment dominating the lower and upper parts and a phase of clay deposition in a lacustrine environment separating these an ar ar analysis on the sanidine contained in a vertisol in the upper part of the sequence gave an age not older than 427 ka an early galerian fauna was collected in clay layers where the jaramillo paleomagnetic event was recognized cold periods are documented in the lower and upper part of the sequence although in the latter the intense weathering caused by the development of a soil with tropical features precludes further investigations the palynological data supported by sedimentological and palaeomagnetic evidence indicate that the sequence can be related to a large part of the bavelian and part of the menapian in the middle part where clay layers outcrop two cool and humid phases are followed by colder and drier periods biological and geological evidence suggests that around 1 my the basin of colle curti was probably located at an elevation of about 600 m

interactions between mantle upwelling drainage evolution and active normal faulting an example from the central apennines italy summary in this paper we show that the processes that have shaped the quaternary surface development of the apennines in central italy are all consequences of a single subcrustal process the upwelling of the mantle the relationship between gravity and topography shows that mantle convection is responsible for a long wavelength 150 200 km topographic bulge over the central apennines and stratigraphic evidence suggests this bulge developed in the quaternary active normal faulting is localized at the crest of this bulge and produces internally draining fault bounded basins these basins have been progressively captured by the aggressive headward erosion of major streams that cut down to the sea on the flanks of the regional bulge the only surviving closed basins are those on the apennine watershed most distant from the marine base level where continued normal faulting is still able to provide local subsidence that defeats their capture by the regional drainage network understanding the competition between regional capture and local fault related subsidence of intermontane basins is crucial for recognizing potentially hazardous active faults in the landscape and also for interpreting the sediment supply to adjacent offshore regions central italy provides a good modern analogue for processes that are probably common in the geological record particularly on rifted margins and intracontinental rifts but may not have been fully appreciated

insights on the opening of the galerian mammal migration pathway from magnetostratigraphy of the pleistocene marine continental transition in the arda river section northern italy abstract we investigated the magnetostratigraphy of the arda river section northern italy where the transition from marine to continental sedimentation occurring in the po river basin during the pleistocene is registered four magnetic polarity reversals were used to construct an age model of sedimentation aided by marine biostratigraphy and tied to a standard 18o curve from the literature the section spans from the olduvai subchron 1 94 1 78 ma across the jaramillo subchron 1 07 0 99 ma up to the brunhes matuyama boundary 0 78 ma the onset of continental deposition occurred during marine isotope stage mis 30 at 1 04 ma an association of villafranchian and early galerian mammals including sus strozzii and ursus dolinensis has been found in the continental sediments dated to mis 29 27 0 99 ma above follows a prominent fluvial conglomerate attributed to the first major lowstand of the pleistocene culminating with mis 22 at 0 9 ma during the late early pleistocene climate turnover ept these and other data from the literature are used to reconstruct the onset of continental deposition in the greater po basin and shed light on the opening of the migration pathway that brought far traveled galerian mammal immigrants to enter europe for the first time during the ept

revisiting the esr chronology of the early pleistocene hominin occupation at vallparadis barcelona spain abstract esr dating was applied to fossil teeth and optically bleached quartz grain samples from two units of the sequence at vallparadis barcelona spain weighted mean esr age estimates of 858 87 ka and 849 48 ka were obtained for evt 7 which includes the archaeological level 10 and evt 8 respectively these results are in good agreement with the existing magneto biostratigraphic framework that constrain these deposits between 780 and 990 ka and indicate that vallparadis evt 7 has a chronology very close to that of atapuerca gran dolina td 6 spain

an early pleistocene interglacial record from an intermontane basin of central italy scoppito l aquila abstract interdisciplinary investigations in the early pleistocene site of madonna della strada near scoppito l aquila central italy are presented complementing the information on large mammal remains recovered in the 1950s mammuthus meridionalis rhinoceros hippopotamus suid and small deer new fragmentary remains of an old rhinoceros individual are examined and discussed pollen analysis documents an interglacial forest phase with considerable frequencies of taxa presently extinct in the italian peninsula tsuga carya pterocarya and zelkova starting with an expansion of conifers progressively replaced by a mixed deciduous forest followed by an increase of mediterranean vegetation the abundance of extinct elements suggests an early pleistocene age older than the jaramillo subchron 1 07 ma the scarcity of picea and cedrus and the absence of liquidambar suggest that the record should be younger than mis 40 approx 1 3 ma this chronological setting indicates that hippopotamus antiquus was already present in italy before the jaramillo palaeomagnetic inversion

eastern european rodent rodentia mammalia faunas from the early middle pleistocene transition abstract the rodent faunas from nine sites on the russian plain and taman peninsula corresponding to the early middle pleistocene transition have been analyzed these localities are situated in the dnieper don dniester and danube drainage basins and in the northern regions of the black and azov seas seven of the sites are associated with the upper part of matuyama reversed polarity chron and located between the beginning of jaramillo event and the brunhes matuyama boundary one of the sites was recovered from the chauda marine deposits of the black sea and referred to the very beginning of brunhes epoch the species composition of the rodent fauna sequence has been established the faunas referred to the jaramillo event 1 1 1 0 ma contain the advanced mimomys steppe lemmings prolagurus pannonicus and lagurodon arankae and allophaiomys pliocaenicus faunas were recovered from korotoyak ostrogozhsk suite roksolany zapadnye kairy and ushkalka localities the more advanced rodent faunas of the morozovian assemblage port katon site include also the first representatives of terricola karai dubina and shamin localities have been found below the brunhes matuyama boundary 0 85 ma including the first representatives of microtus microtus ex gr oeconomus and microtus arvalinus the pitymys like voles microtus stenocranius hintoni steppe lemming p pannonicus and yellow steppe lemming eolagurus argyropuloi compose the core of these faunas the litvin locality located in the deposits of the chauda transgression of the black sea and corresponding to the very beginning of the middle pleistocene contains a rodent fauna closely resembling the shamin one it yielded the remains of mimomys savini advanced a pliocaenicus p pannonicus microtus stenocranius hintoni microtus ex gr oeconomus and mcirotus arvalinus thus numerous data permit elucidation of the history of rodent faunas of the russian plain during early middle pleistocene transitions and reveal the definitive stages in their evolution

the high resolution sequence stratigraphy and the mammal fossil record a test in the middle upper pleistocene deposits of the roman basin latium italy abstract in the campagna romana area pleistocene vertebrate fossil remains are preserved both in continental and marine sedimentary successions this fact favoured the identification of faunal complexes in agreement with the biochronologic setting proposed for the plio pleistocene large mammal faunas of the italian peninsula at the same time the detailed facies and sequence stratigraphic analyses carried out in the last years on such deposits have allowed establishment of a regional and local chronostratigraphic framework which sets some physical and temporal limits to the occurrence of faunal complexes in this light the study of the pleistocene deposits of the roman basin based on sequence stratigraphy and mammal biochronology approach can constitute a significant tool to test the relationships among physical stratigraphic units faunal complexes and faunal units in the examined area the fossiliferous levels are essentially found in transgressive fluvial and fluvio palustrine deposits filling incised valleys tst and in highstand barrier island lagoon deposits hst excluding some cases where bones show a probable exhumation process whole discovered mammal remains are mostly coeval with deposits containing them based on taphonomic considerations and on depositional and physical stratigraphic settings a correlation scheme among roman pleistocene sequence stratigraphic units local faunal complexes and italian mammal biochrons is proposed nevertheless many problems remain to be clarified before either the correlation between events and the geochronological framework or the significance and the biochronological value of each faunal assemblage can be considered as definitive

the umbria marche arcuate fold belt italy abstract in this paper the structural setting of the umbria marche fold belt is briefly described the basement cover relationships and the primary or secondary origin of the arcuate shape are also discussed mainly on the basis of structural data it is suggested that the umbria marche fold belt can hardly be the result of a thin skinned tectonics under little overburden but one or more deep seated detachment levels must have worked thick skinned tectonics during the mio pliocene transpressional phase furthermore an orocline origin for the arcuate shape of the fold belt resulting from a progressive history of oblique right lateral shearing is suggested during the first deformative stage stage 1a late miocene the cover detached from the basement is deformed by a nw se trending linear fold belt whilst the basement is deformed by oblique right lateral shear then stage 1b the linear fold belt is progressively bent by right lateral dragging in correspondence with the deep seated shear zones during the second deformative stage stage 2 early piocene the cover deforms in connection with the basement the northern and the central sectors of umbria marche apennines undergo a prevailing shortening accomodated by nw se nnw sse dip slip thrusting the southern sector undergoes a prevailing right lateral shearing accommodated by nne ssw oblique thrusting

stochastic seismic response of a slope based on large scale shaking table tests abstract slopes should be regarded as stochastic dynamic systems when investigating the uncertainty of ground motions in engineering this involves the propagation and spatial evolution of physical quantities e g acceleration that can be assessed with some probability more specifically stochastic stability and amplification effects are important issues under random seismic inputs in studying the above a large scale shaking table test is carried out to investigate the slope seismic response under random earthquake ground motions where 144 ground motion samples are generated using a time evolution power spectrum model in this test acceleration evolves in a way that its pdf changes with time and space in the time domain the pdf variability first increases and then decreases with the progression of the earthquake in the spatial domain the pdf variability increases upslope indicating that the mean and standard deviation of amplification factors increase with elevation moreover the stability of the upper part of the slope stochastic dynamic system is poor meanwhile the de amplification effect of the slope toe is identified under random seismic inputs finally we discuss different amplification factors and consider applications of the research results in slope engineering

pollen and mammals from the late early pleistocene site of saticula sant agata de goti benevento italy abstract a fluvio lacustrine succession was discovered in 1995 at saticula near sant agata de goti benevento below a thick volcaniclastic deposit sealed by the ignimbrite campana formation 39 ka vertebrate fossil remains and pollen were recovered in the excavated sections pollen analysis allowed recognition of two pollen zones the first being characterised by a quercus carya mixed deciduous forest which was probably present in the plain and on the slopes surrounding the caudina valley basin the following samples record a drastic decrease in carya pollen grains and the contemporary increase in herbs and pinus a more open environment established around the river shores due to a climate shift towards dryer conditions most of the vertebrate remains were found in the upper portion of the succession corresponding to the zone with reduced carya pollen the fossil mammal assemblage includes hippopotamus antiquus axis eurygonos megacerini indet equus suessenbornensis and stephanorhinus cf s hundsheimensis in addition a partial unerupted molar of an elephantid two hyena coprolites and fragments of rodent teeth were identified the high amount of carya at the base of the succession represents the most peculiar feature of the saticula floral record and was used as a reference for its chronological constraint comparison with other italian pollen successions allowed the saticula record to be tentatively ascribed to the late early pleistocene after that period carya was never recorded in such high amounts and gradually disappeared from the italian flora following a heterochronous latitudinal gradient the saticula mammal assemblage is in agreement with the chronological framework suggested by pollen data

landslides induced by the 2008 wenchuan earthquake sichuan china the 2008 wenchuan earthquake with a magnitude of mw 7 9 induced numerous slope movements on the hanging walls of fault surface ruptures and on steep inner valleys along the minjiang river landslide moving directions showed preferred orientations normal to the fault ruptures indicating the effect of the directivity of the seismic wave the most common landslides were of carbonate rocks which are easily dissolved and decrease the contact surfaces the largest non volcanic landslide in history was induced in bedded dolomite by the earthquake and was preceded by gravitational deformation with ridge top depressions valley fill materials were mobilized at 36 locations probably by pore water pressure build up

the lacustrine deposits of fornaci di ranica late early pleistocene italian pre alps stratigraphy palaeoenvironment and geological evolution an interdisciplinary investigation of the pleistocene clay succession of fornaci di ranica italian pre alps aimed to reconstruct the palaeoenvironmental history and its chronostratigraphic position and to consider the implications for the quaternary evolution of the southern alpine borderland near the early middle pleistocene transition a detailed survey of quaternary deposits in boreholes and exposed sections provided a complete record of the basin the most complete core was analyzed for palynology and magnetic properties plant macrofossils were obtained by flotation pollen and spectrometric analysis allowed a precise stratigraphic placement of a moose antler and braincase kept in museum collections the basin originated from fluviatile obstruction of a tributary valley cut into bedrock the basal deposits formed as a terrestrial hydromorphic soil under a dense tsuga forest zone rnc 1 the overlying palustrine gyttja shows a marked forest withdrawal with a climatic signature zone rnc 3 followed by a re establishment of mixed conifer forests zones rnc 4 6 the occurrences of pollen of cold adapted taxa saxifraga oppositifolia type saxifraga stellaris type larix are the oldest so far known south of the alps and suggest that mean summer temperature was near or even below the thermic tree limit high herb diversity partially represented by tall forbs characterizes this zone a further increase of the water table can be assumed in zones rnc 4 and rnc 5 since pollen of aquatic plants increases the find of larix decidua l cones demonstrates the existence of the european larch in the early pleistocene of the alps previously not identified at the species level after the serio river had reached the maximum quaternary aggradation the lake was rapidly filled up with turbiditic sediments the identification of cervalces latifrons johnson 1874 by azzaroli palaeantogr italica 71 1979 48 was confirmed pollen spectra obtained from clay fragments preserved in the braincase allowed us to constrain the stratigraphic position of these fossil remains in the lower palustrine portion of the sequence pollen and moose palaeoecology corroborate the reconstruction of a boreal landscape the succession of fornaci di ranica is attributed to the late early pleistocene on the basis of the following elements i the occurrence of an acme pollen zone of tsuga with carya and pterocarya ii the low representation of cedrus iii the biochronology of cervalces latifrons iv normal fossil magnetic polarity interpreted as part of the jaramillo subchron on the basis of correlations with other studied sections from the same region and finally v indications from the regional geological evolution the basin deposits spanned the final stage of a temperate period and the subsequent transition to a cold phase during the jaramillo subchron or the cobb cryptochron the basin originated by fluvioglacial aggradation triggered by glaciation in the northern part of the serio river catchement the lake succession may represent an episode of marked increase of polar ice volume related to mis 36 30 or 28 the correlation with the leffe sequence also suggests that cold climate conditions inferred for pollen zone rnc 3 did not occur earlier in the early pleistocene of this region

a long pollen record from laghi di monticchio southern italy a preiminary account a pollen diagram from lake monticchio a volcanic crater lake in s central italy east of naples shows a long vegetation record for the holocene and the later portion of the last weichselian glacial period the upper 735 cm of a 2550 cm core is assigned to the holocene it begins with expansion of betula birch and quercus oak followed by fagus beech tilia lime and other mesic trees in the next phase the flora is dominated by oak with an increase in herb pollen in the later holocene the flora is again diversified by the appearance of abies fir curpinus hornbeam and other trees in the latest pleistocene portion of the core the vegetation is dominated by grasses artemisia sage brush and chenopods indicating a treeless environment the base of the core shows continued dominance by steppe like vegetation with 9interstadial9 episodes in which trees especially oak beech and fir were abundant the climatic interpretation is that the late pleistocene was very dry at least in the summer growing season and probably although not necessarily colder than now in the holocene increased precipitation favoured expansion of tree populations for a brief period there was a return of water stress in the growing season marked by a loss of tree species diversity and an increase in herbs in the later holocene a progressive diversification of tree species indicates a return to a more humid and perhaps cooler climate the vegetation history and climatic inferences are closely similar to records available from greece the available radiocarbon dates which show a consistent pattern indicate that the core is much older than 40000 years at the base but not old enough to include the major post eemian interstadials the 9holocene9 birch expansion began nearly 20000 years ago these dates appear to be systematically too old in the light of present knowledge the preliminary character of the study is emphasized further radiocarbon dates especially of the 9holocene9 section are needed as are more detailed studies of sedimentation processes and tephra occurrences

mid and low latitude prompt penetration ionospheric zonal plasma drifts we have used ion drift observations from the de 2 satellite to determine the latitudinal variation and the temporal evolution of mid and low latitude prompt penetration zonal plasma drifts driven by magnetospheric electric fields our results indicate that sudden increases in convection lead to predominantly westward perturbation drifts which decrease equartorwards and have largest amplitudes in the dusk midnight sector the diurnal perturbation drift patterns shift to later local times with increasing storm time and decay to new quasi equilibrium values in about 2 hours as the ring current readjusts to the new polar cap potential the daily and latitudinal variations and temporal evolution of the de 2 prompt penetration drifts are generally in good agreement with predictions from the rice convection model although the experimental results show larger amplitudes and longer shielding time constants

reconstructing the palaeoenvironments of the early pleistocene mammal faunas from the pollen preserved on fossil bones abstract we carried out a systematic investigation on the pollen content of sediment adhering to skeletal elements of large mammals which originate from the long lacustrine record of leffe early pleistocene of the italian alps three local faunas were discovered during mining activities along the intermediate part spanning from 1 5 to 0 95 ma of the basin succession the excellent pollen preservation allowed testing the reproducibility of the pollen signal from single skeletons a clear palaeoenvironmental patterning consistent with the ecological preferences of the considered mammal species emerged from the canonical correspondence analysis of pollen types diagnostic for vegetation communities edaphic factors related to seasonal river activity changes and to the development of swamp forests in the riverbanks are significantly associated to the occurrences of hippopotamus cf antiquus whereas finds of mammuthus meridionalis belong to fully forested landscapes dominated by conifer or mixed forests of oceanic warm to cool temperate climate rhinoceros habitats include variable forest cover under different climate states distinct cool temperate partially open vegetation could be recognized for large deer included cervalces cf carnutorum a palynostratigraphic correlation between individual spectra and a reference palynostratigraphic record allowed assignment of many fossil remains to a precise stratigraphic position this procedure also shown that the leffe local faunas include specimens accumulated under different environmental and climate states as a consequence of high frequency climate changes characterizing the late villafranchian early pleistocene

electrodynamic response of the ionosphere to high speed solar wind streams 1 a combination of dawn and dusk observations from the dmsp f13 satellite and output from the thermosphere ionosphere electrodynamics general circulation model tie gcm are used to study the electrodynamic response of the ionosphere to quasi 9 day recurrent geomagnetic activity driven by solar wind high speed streams during 2005 superposed epoch analysis of the zonal and vertical plasma drifts reveal that significant electrodynamic perturbations occur in response to the high speed streams during 2005 the peak response occurs around 0 5 days after the high speed stream interface and the drift perturbations slowly relax back to quiet levels over 4 6 days the observed and modeled zonal drift perturbations are in good agreement near dusk however the amplitude of the zonal drift perturbations at dawn slightly differ at low and midlatitudes the modeled drift perturbations are westward at all local times with the largest westward drifts occurring near midnight at dawn the dmsp observations at low and midlatitudes reveal 20 m s 1 eastward drift perturbations while the tie gcm simulates weaker eastward drifts at midlatitudes and westward drifts in the equatorial region at dusk the low and midlatitude perturbation drifts are 10 20 m s 1 westward in both the dmsp observations and tie gcm simulations owing to equatorial expansion and strengthening of the high latitude two cell convection pattern the high latitude zonal drift perturbations are eastward in the morning and westward in the afternoon and evening less agreement is present between the simulated and observed vertical drift perturbations near dawn at all latitudes upward drift perturbations are revealed by both the tie gcm simulation 5 m s 1 and dmsp observations 10 15 m s 1 however at dusk the dmsp observes an upward drift perturbation on the order of 25 35 m s 1 while the tie gcm simulates vertical drift perturbations less than 10 m s 1 the disagreement may be related to errors in the dmsp observations or deficiencies in the model based on the results presented we conclude that the disturbance dynamo mechanism is an important mechanism for driving the electrodynamic response at dawn and dusk to recurrent geomagnetic activity driven by solar wind high speed streams

shaking table tests and stability analysis of steep nailed slopes shaking table tests were performed on five model slopes to examine the effects of the angle and length of the nails and the frequency of excitation on the seismic resistance and failure mechanism of the slopes seismic excitation was also applied to slopes at various angles experimental results showed that nails markedly improved the seismic resistance of all model steep slopes additionally nailed slopes exhibit characteristics of ductility under strong excitation the angle of the nails influences the deformation of the slope but only slightly affects seismic resistance an increase in the length of the nails increased the seismic resistance of the slope and reduced the displacement of the facing only when subjected to strong excitation the slope at an angle of 90 to the horizontal has a markedly lower seismic resistance than that at 80 the rocking of the model slope was strong for the slope with inclined nails and the slope at 90 to the horizontal the failure surface of the soil mass is approxi

comparison between reprocessed seismic profiles seismologic and geologic data a case study of the colfiorito earthquake area seismic reflection data are used to reconstruct the subsurface geologic structures below the umbria marche region in italy a highly seismogenic area with a recent history of seismic activity the 1997 1998 colfiorito sequence we reprocess three vibroseis seismic profiles acquired in the early 1980s for hydrocarbon exploration whose stacked sections were optimized for relatively deep oil targets on the reprocessed seismic profile closest to the epicentral area we construct the main reflectors to a depth of about 4 s two way time and compare this interpretation with the available hypocenters of the 1997 earthquakes the improvements in visualizing the shallow and deep reflections provide a better correlation between the reflectors and the observed surface structures as well as a better delineation of the basement rock geometry we find that part of the colfiorito sequence is localized around some of the reflectors in the reflection profile which we interpret as related to the active normal faults

connecting seismically active normal faults with quaternary geological structures in a complex extensional environment the colfiorito 1997 case history northern apennines italy 1 the northern apennines of italy are characterized by a complex tertiary tectonic history where superposed compressional and extensional deformation occurred in such regions characterized by low active extensional strain rate the coseismic surface ruptures are rare and often a matter of much debate resulting in a difficult connection between geological faults i e faults which can be mapped at the surface and seismological faults i e faults which actually generate earthquakes the availability of detailed geological mapping and high resolution seismological data for the colfiorito area struck in 1997 by a sequence of six 5 mw 6 normal faulting earthquakes allow us to compare and verify the existence of geometric and kinematic correspondence between the mapped geological quaternary faults and the activated structures in map view the earthquakes distribution reflects the fault pattern mapped at the surface the length of activated and mapped faults is quite similar 7 10 km the coseismic subsided region imaged by interferometric synthetic aperture radar data is located in the hanging wall of the mapped normal faults that bound the quaternary basins in section view there is a geometric connection between mapped normal faults and the aftershock alignments used to image fault geometry at depth comparison of striated fault planes and aftershock focal mechanism solutions show a strong kinematic consistency this study points out that the quaternary tectonosedimentary evolution and the present day geological and geomorphologic setting of the colfiorito area can be interpreted as the result of repeated extensional earthquakes similar to the 1997 events occurring on nw se trending normal faults our data also show that the main shocks of the colfiorito sequence nucleated close to the intersections between the normal faults and the preexisting compressional transpressional structures which in 1997 acted as lateral barriers to rupture propagation and consequently constrained the fault size

quaternary basin evolution and present tectonic regime in the area of the 1997 1998 umbria marche seismic sequence central italy abstract geological and geomorphological surveys have been performed in the area affected by the 1997 1998 umbria marche seismic sequence m max 6 0 aimed at defining the quaternary tectonic history and the characteristics of the present tectonic regime data have been collected from 1 the analysis of the remnant landsurfaces by means of aerial photos and field surveys 2 geological surveys in the cesi san martino basin and in the easternmost sector of the colfiorito basin in order to identify deformative features affecting the quaternary deposits 3 the analysis of boreholes and geo electrical data derived from previous surveys performed in the 1960s in order to reconstruct the top of the pre quaternary substratum in the colfiorito basin two different successions of remnant landsurfaces have been identified along the faults bounding the basins to the east in the hangingwall and the footwall respectively the difference accounts for a fault controlled evolution of the landscape at least during the upper pliocene early pleistocene the deformation affecting the quaternary deposits and landforms in the investigated basins indicates a decreasing tectonic activity along the master faults since the middle pleistocene surface deformation due to tectonics is faint and displayed by gentle warping of the landforms during the late quaternary as for the basin geometry subsurface data show that two minor depressions formed in the colfiorito basin during the quaternary the oldest one close to the fault bounding the basin while the youngest and deepest formed in the inner portion of the basin therefore the present geometry is different from that of other fault bounded quaternary depressions of the central apennines typically half graben basins showing the maximum depth of the substratum in the area close to the master fault tectonic history may be summarised as follows 1 origin of the quaternary fault bounded colfiorito and cesi san martino basins 2 evolution of the basins with a half graben style 3 significant reduction of tectonic activity since the middle pleistocene during the third phase the evolution of the basins is no longer related to a half graben style in the case of the colfiorito basin a new depression is superimposed to on the previous half graben whose evolution is related to the lowering of the inner portion of the basin through warping moreover present activity does not result in fault related surficial displacements but only in continuous deformation spread over the basins these conclusions have fundamental implications for the seismotectonic framework of the 1997 1998 earthquake sequence this deformation style is indeed in agreement with the coseismic deformation modelled by means of the sar interferometry analyses carried out by other institutions during the seismic sequence and with the lack of evident surface faulting related to the mentioned events in the investigated area this evidence indicates that the evolution of the investigated area since the middle pleistocene resulted from the summation of deformative episodes similar to that which occurred during the recent seismic sequence as a consequence no earthquakes with magnitude larger than 6 are expected in the area

the gubbio normal fault central italy geometry displacement distribution and tectonic evolution abstract normal faults within orogenic belts can be pre syn or post orogenic features we studied the gubbio normal fault central italy which is an example of a pre orogenic fault reactivated in a post orogenic stage the gubbio fault is a 22 km long fault bordering a quaternary basin and part of an active faults system in the umbria marche region central italy the interpretation of a set of seismic profiles enables us to reconstruct the fault geometry in detail and to measure displacement and throw distributions along the fault strike seismic data indicate that the gubbio fault represents an example of multiple reactivation at least a portion of the fault was active in the miocene and only a part of the total displacement was achieved in the quaternary the reconstruction of the fault geometry at depth shows that the fault is characterised by listric geometry the fault is also characterised by a bend along strike and structure contours show that this geometry is maintained at depth as the fault is commonly addressed as presently active the maximum fault dimensions are correlated to the maximum expected earthquake and the presence of the fault bend is discussed as a possible barrier to seismic ruptures propagation

performance of piles with different configurations subjected to slope deformation induced by seismic liquefaction abstract liquefaction induced lateral ground deformation has been a common observation during many past earthquakes piles are widely used in liquefaction prone areas and their performance under such circumstances has become an important issue for researchers and engineers previous studies on this issue have focused primarily on piles located behind quay walls or in level ground conditions which have considerably different boundary conditions compared to those of an inclined sloping ground condition that is more common for waterfront structures this study presents a series of shaking table tests modeling the performance of piles subjected to liquefaction induced slope deformation different pile configurations including single piles piles aligned in one row parallel to the direction of the slope piles aligned in one row perpendicular to the direction of the slope and piles in a 3 3 configuration were tested several aspects regarding the behaviors of excess generation of pore water pressure pile bending moment and lateral slope deformation under different pile configurations were revealed and discussed the results obtained in this study can be used for validation of related numerical approaches or as benchmarks that can further facilitate performance based pile designs in liquefaction prone areas

climatology of f region zonal plasma drifts over jicamarca 1 we use extensive incoherent scatter radar observations made at the jicamarca radio observatory between 1970 and 2003 to study and model empirically the equatorial zonal plasma drifts near the f region peak using bernstein polynomials as base functions our quiet time model results confirm that the daytime drifts are westward and are nearly season and solar cycle independent the nighttime drifts are eastward have larger magnitudes and increase strongly with solar flux particularly near equinox and december solstice enhanced geomagnetic activity drives small eastward perturbation drifts during the day and much larger westward disturbance drifts at night the nighttime drift perturbations are largest near midnight and increase strongly with solar flux near equinox and december solstice but are essentially absent near june solstice the jicamarca zonal disturbance drifts can be largely accounted for by disturbance dynamo electric fields with a dominant time delay of about 3 15 hours following enhanced geomagnetic activity in the postmidnight sector there are also smaller westward disturbance drifts associated with time delays of about 15 24 hours and perhaps even longer our results strongly suggest that the longitudinal dependence of both the quiet and disturbed equatorial nighttime zonal drifts varies with season

radar and satellite global equatorial f region vertical drift model we present the first global empirical model for the quiet time f region equatorial vertical drifts based on combined incoherent scatter radar observations at jicamarca and ion drift meter observations on board the atmospheric explorer e satellite this analytical model based on products of cubic b splines and with nearly conservative electric fields describes the diurnal and seasonal variations of the equatorial vertical drifts for a continuous range of all longitudes and solar flux values our results indicate that during solar minimum the evening prereversal velocity enhancement exhibits only small longitudinal variations during equinox with amplitudes of about 15 20 m s is observed only in the american sector during december solstice with amplitudes of about 5 10 m s and is absent at all longitudes during june solstice the solar minimum evening reversal times are fairly independent of longitude except during december solstice during solar maximum the evening upward vertical drifts and reversal times exhibit large longitudinal variations particularly during the solstices in this case for a solar flux index of 180 the june solstice evening peak drifts maximize in the pacific region with drift amplitudes of up to 35 m s whereas the december solstice velocities maximize in the american sector with comparable magnitudes the equinoctial peak velocities vary between about 35 and 45 m s the morning reversal times and the daytime drifts exhibit only small variations with the phase of the solar cycle the daytime drifts have largest amplitudes between about 0900 and 1100 lt with typical values of 25 30 m s we also show that our model results are in good agreement with other equatorial ground based observations over india brazil and kwajalein

biochronology and biochron boundaries a real dilemma or a false problem an example based on the pleistocene large mammalian faunas from italy abstract reconstructing the neogene quaternary biostratigraphy in continental environments and recognising boundaries between successive mammalian faunal complexes is a problematic task the definition and application of biochronology has been often tainted by references to and inferences from biostratigraphy actually the discontinuities in the continental sedimentary record environmental conditions taphonomic and sampling biases are responsible for the fact that the stratigraphical order of the lowest and highest occurrences of fossil remains stratigraphic datum does not necessarily reflect the temporal order of actual first last appearances of taxa palaeobiological events in time nonetheless the first last appearance bioevents recorded by lowest highest occurrences of fossil remains in fossiliferous levels of different continental stratigraphical successions have been the principal foundation for establishing the biochronological setting of continental mammal faunas therefore from a theoretical point of view boundaries should be defined by the oldest and or youngest historical occurrence of one or more taxa what about an operational approach some examples of the italian faunas are presented focusing on the transition from the villafranchian to the galerian and from the galerian to the aurelian land mammal ages the results obtained indicate the difficulty of defining a stable scheme that can be applied for correlation by the international scientific community

pollen record from colle curti and cesi early and middle pleistocene mammal sites in the umbro marchean apennine mountains central italy the palynological record from the colle curti and cesi continental deposits has been examined in order to identify the main palaeofloristic and vegetational changes between 0 99 and 0 6 0 7 ma these data show a progressive increase in aridity as well as a progressive decrease in temperature which are associated with the transition in dominance from the 41 to 100 ka cyclicity in the milankovitch orbital record during the middle pleistocene the disappearance of tsuga recorded during the lower part of the brunhes chron also has been related to a shift in global aridity during the successive open vegetational phases glacials chenopodiaceae and artemisia progressively increase whereas cyperaceae decrease forest phases interglacials are successively dominated by tsuga abies with picea and finally pinus but all lack significant expansion of broad leaved deciduous taxa palynological and sedimentological data in addition to taphonomic interpretations demonstrate the occurrence of several hiatuses in the lower parts of the interglacials these hiatuses are considered to represent the palaeoenvironmental response to climatic changes affecting local sedimentological and geomorphological conditions copyright 2000 john wiley sons ltd

statistical seismic landslide hazard analysis an example from taiwan abstract following the work of lee et al 2008a a statistical approach is applied to seismic landslide hazard analysis for the whole of taiwan all the work is done using new data sets which include a new and carefully mapped chi chi earthquake induced landslide inventory a 5 m dem and a new version of the 1 50 000 scale geologic map of taiwan landslide causative factors used in the susceptibility analysis include the slope gradient slope aspect terrain roughness slope roughness total curvature total slope height and lithology the corrected arias intensity taking topographic amplification into consideration is used as a triggering factor firstly a susceptibility model is built using the 1999 chi chi shallow landslides as a training data set and multivariate logistic regression as the analytical tool this model is validated by using the 1998 jueili earthquake induced landslide data then a probability of failure curve is established by comparing the chi chi landslide data and the susceptibility values after which the spatial probability of landslide occurrence is drawn the temporal probability may be accounted for with the triggering factor the hazard level of the arias intensity which was obtained through regular probabilistic seismic hazard analysis finally the susceptibility model and the probability of failure curve are applied to the whole of taiwan using the topographically corrected 475 year arias intensity as a triggering factor to complete a seismic shallow landslide probability map for ground motions having a 475 year return period

analysis on mechanism of landslides under ground shaking a typical landslide in the wenchuan earthquake a high steep rock hill with two side slopes near national road 213 is used as a prototype in this paper the full process from initial deformation to sliding of the slope during ground shaking is simulated by a new discrete element method continuum based discrete element method then the seismic responses of a high steep rock hill with two side slopes are researched from the base of time frequency and joint time frequency domain using hilbert huang transform and fourier transform the findings are first the stress concentration phenomenon occurs at the top of the sliding mass and then some tension and shear failure points appear which expand from the top toward the toe of the sliding mass along the structural plane at the same time the number of tension failure points gradually increases then the toe of the sliding mass fails and shears out from its toe which results in the landslide if the material parameters are under the same conditions the landslide in the middle of the slope occurs before that at the foot of slope and the starting time of landslide and the arrival time of the peak ground acceleration are synchronous or the former slightly lags behind the latter the difference of distribution and dissipation of earthquake energy in the sliding body and sliding bed is the major influence factor to induce the landslide when the accelerations are small the instantaneous frequency of accelerations between sliding bed and sliding body is generally consistent the energy transmittance coefficients of the sliding structural plane and the controlled frequency band of the energy all range in a limitation with the increase of the seismic intensity the instantaneous frequency and the energy transmittance coefficients gradually decrease and then they are steady within the lower limitation at the same time the controlled frequency band also shifts gradually from high frequency band to the lower one based on the input seismic wave the peak acceleration amplifies as the increase of elevation regardless of the monitoring points on the steep slope gentle slope side or inside of the slope generally speaking amplification of the vertical peak acceleration is stronger than that of the horizontal peak acceleration and amplification of the peak acceleration on a steep slope is stronger than that on a gentle slope and that of inside of the slope is the weakest amplification

empirical high latitude electric field models electric field measurements from the dynamics explorer 2 satellite have been analyzed to extend the empirical models previously developed from dawn dusk ogo 6 measurements j p heppner 1977 the analysis embraces large quantities of data from polar crossings entering and exiting the high latitudes in all magnetic local time zones paralleling the previous analysis the modeling is based on the distinctly different polar cap and dayside convective patterns that occur as a function of the sign of the y component of the interplanetary magnetic field the objective which is to represent the typical distributions of convective electric fields with a minimum number of characteristic patterns is met by deriving one pattern model bc for the northern hemisphere with a y interplanetary magnetic field imf and southern hemisphere with a y imf and two patterns models a and de for the northern hemisphere with a y imf and southern hemisphere with a y imf the most significant large scale revisions of the ogo 6 models are 1 on the dayside where the latitudinal overlap of morning and evening convection cells reverses with the sign of the imf y component 2 on the nightside where a westward flow region poleward from the harang discontinuity appears under model bc conditions and 3 magnetic local time shifts in the positions of the convection cell foci the modeling above was followed by a detailed examination of cases where the imf z component was clearly positive northward neglecting the seasonally dependent cases where irregularities obscure pattern recognition the observations range from reasonable agreement with the new bc and de models to cases where different characteristics appeared primarily at dayside high latitudes the analysis of these differences for strong bz conditions using passes through different mlt zones led to finding that the deviations from both the bc and de models could be modeled by extending the evening cell foci toward and beyond noon with a deformation that roughly resembles a rotational twist of the extended evening cell the morning cell accommodation to the model bc deformation produces a narrow tongue of eastward convection near 75 invariant latitude on the dayside the model de deformation compresses the morning cell toward the night hours such that the sunward convection in the morning cell is diverted to polar latitudes in the 0400 to 0700 mlt sector in both cases the deformations of the two cell patterns lead to sunward convection in dayside polar regions while maintaining the integrity of the nightside convection pattern thus the nightside dilemmas that plague three and four cell models designed to explain sunward convection in polar regions under bz conditions do not appear

reassessing the sedimentary deposits and vertebrate assemblages from ponte galeria area rome central italy an archive for the middle pleistocene faunas of europe abstract the ponte galeria area is part of the larger campagna romana and hosted the inner delta of the tiber river since the beginning of the middle pleistocene allowing the deposition of a series of glacio eustatically controlled fluvial lacustrine sedimentary successions very rich in fossil mammal remains due to its richness of fossiliferous sites this area represents an exceptional archive for the study and understanding of the biochronological paleobiogeographical and paleoenvironmental evolution during the middle pleistocene in europe a series of recent studies using the 40 ar 39 ar ages of tephra intercalated within the sedimentary deposits provided a large amount of geochronological data linking these aggradational successions to the different marine isotopic stages in the present paper we present a complete review of the faunal assemblages identified so far in the ponte galeria area and we constrain the ages of the faunal units by placing them within the new chronostratigraphic scheme by means of this interdisciplinary approach we re calibrate the mammal assemblages collected in this area and reconstruct a new biochronological and paleobiogeographic framework for the italian peninsula during the middle pleistocene in particular we distinguish six well defined biochronological units slivia ponte galeria isernia fontana ranuccio torre in pietra and vitinia in the studied area covering a time span of ca 0 6 myr from the early to middle pleistocene transition to at least marine isotope stage 7 this period is characterized in europe by the mid pleistocene revolution global climate change and by the transition at first between villafranchian and galerian taxa and later between the galerian and aurelian ones according to the reviewed data the persistence of villafranchian taxa is recorded in italy at the beginning of the middle pleistocene probably due to favorable climatic conditions or delay in dispersal of competitive species while the faunal turnover between the villafranchian and galerian species was completed around 0 6 0 5 ma during this time bos primigenius and other temperate warm taxa were widespread in the peninsula earlier than in western europe in contrast typical aurelian taxa usually related with temperate cold climatic conditions ursus spelaeus megaloceros giganteus occurred later in italy than in other western european areas

effect of sudden stratospheric warming on lunar tidal modulation of the equatorial electrojet 1 using the equatorial electrojet eej peak current intensity as deduced from champ magnetic observations from the years 2001 through 2009 we investigated the relationship between sudden stratospheric warming ssw and lunitidal signatures in the tropical ionosphere there is a practically one to one correspondence between midwinter ssw periods and the strongest 13 day modulation of the eej strength as observed by champ that is all the midwinter ssw periods from december 2001 to august 2009 were accompanied by an enhanced 13 day modulation of the eej strength no other geophysical phenomenon brought about as strong a 13 day modulation as those of the midwinter ssw periods during each midwinter ssw period the amplified 13 day modulation of the eej strengths starts roughly within 1 week around the first peak in stratospheric temperature difference an oscillation with a period of 13 26 days is predicted by the lunitidal equation when considering the precession of the champ orbit when fitting the lunitidal equation to the eej modulations during the midwinter ssw periods consistent phase delays of 4 4 0 3 days of the tidal signal emerge for all the cases the results suggest that the pronounced 13 day modulation of the eej strength is related to an enhancement of the lunar tide in the ionosphere by the ssw effect