87sr 86sr isotope composition of bottled british mineral waters for environmental and forensic purposes mineral waters in britain show a wide range of 87 sr 86 sr isotope compositions ranging between 8 7 sr 86 sr 0 7059 from carboniferous volcanic rock sources in dunbartonshire scotland to 87 sr 86 sr 0 7207 in the dalradian aquifer of aberdeenshire scotland the 87 sr 86 sr composition of the waters shows a general correlation with the aquifer rocks resulting in the waters from older rocks having a more radiogenic signature than those from younger rocks this wide range of values means that the sr isotope composition of mineral water has applications in a number of types of studies in the modern commercial context it provides a way of fingerprinting the various mineral waters and hence provides a method for recognising and reducing fraud from an environmental perspective it provides the first spatial distribution of bio available 87 sr 86 sr in britain that can be used in modern historical and archaeological studies

first observations of polar mesosphere summer echoes in antarctica a 25 kw peak power 50 mhz radar was installed at the peruvian base on king george island antarctica 62 s in early 1993 a search for polar mesospheric summer echoes pmses was made during late january and early february of the first year of operation with negative results these results have been reported in the literature balsley et al 1993 1995 we report here results obtained during the austral summer of the second year 1994 of operation observations during the second year were begun earlier i e closer to the austral summer solstice pmses were observed during this period albeit the echoes were much weaker than what one would expect based on earlier poker flat radar results at a comparable latitude 65 n in the northern hemisphere a large and measurable asymmetry in pmse strength in the two hemispheres therefore exists we explain this asymmetry by postulating a difference in summer mesopause temperatures between the two hemispheres of 7 5 k this difference has been estimated using an empirical relationship between the variations of the poker flat pmse power as a function of temperature given by the mass spectrometer incoherent scatter extended msise 90 model

rock avalanches caused by earthquakes source characteristics study of a worldwide sample of historical earthquakes showed that slopes most susceptible to catastrophic rock avalanches were higher than 150 meters and steeper than 25 degrees the slopes were undercut by fluvial or glacial erosion were composed of intensely fractured rock and exhibited at least one other indicator of low strength or potential instability

the trollheim alluvial fan and facies model revisited widely held fundamental alluvial fan facies concepts generated in past literature based on the trollheim fan deep springs valley california are inconsistent with the actual characteristics of this fan previous publications have established mostly without field study that the trollheim fan consists of debris flow sieve lobe sheetflood and channel facies debris flow and sieve deposits comprise the proximal area giving way to channel or sheetflood deposits distally contrary to these views clayey and gravelly matrix supported debris flow deposits dominate all parts of the trollheim exposures suggesting that this fan has been built almost exclusively by mass wasting events channel fill deposits constitute only a small component of the fan and most are restricted to the proximal area where they have an inset relationship with debris flow sequences the channel facies consists of laterally restricted clast supported gravel lenses formed primarily through the winnowing of debris flow fines by streamflow the most widespread facies on the surface of the fan is a mantle of varnished matrix free pebbles cobbles and boulders that commonly are distributed in radially oriented lobes or levees characteristic of debris flow deposits this mantle was produced by the surficial winnowing of the fine fraction from debris flow deposits primarily by overland water flow in contrast to previous conclusions sheetflood and sieve deposits were not identified anywhere on the fan additionally many of the facies depicted in the widely cited trollheim vertical profile including ripple bedded sand cross bedded sand and overbank mud are not present on or in stratigraphic cuts of the fan after which the profile was named

persistent alluvial fanhead trenching resulting from large infrequent sediment inputs we present laboratory and field evidence that in mountainous catchment fan systems persistent alluvial fanhead aggradation and trenching may result from infrequent large sediment inputs we suggest that the river fan systems along the fault bounded range front of the western southern alps new zealand are likely to be in a dynamic equilibrium on 103 yr timescales superimposed on which their fanheads undergo long term cumulative episodic aggradation these fanheads are active only in rare events do not take part in the usual behaviour of the catchment fan system and require much longer to exhibit dynamic equilibrium than the rest of the fan these findings 1 increase our knowledge of the effects of extreme events on alluvial fan morphodynamics in humid climates 2 question the general applicability of inferring past climatic or tectonic regimes from alluvial fan morphology and stratigraphy and 3 provide a conceptual basis for hazard zonation on alluvial fans copyright 2006 john wiley sons ltd

late quaternary activity along the lone pine fault eastern california the lone pine fault is a north trending secondary break of the owens valley fault zone 1 4 km west of lone pine california this fault forms an east facing scarp as much as 6 5 m high across an abandoned outwash fan of the tioga latest pleistocene glaciation the fault experienced large right lateral and smaller vertical displacement during the 1872 owens valley earthquake knowledge of the character and amount of slip at this site in and before 1872 is necessary for evaluations of earthquake hazard near owens valley and may help us to understand earthquakes along other parts of the eastern front of the sierra nevada and in the great basin scarp profiles indicate a 1 to 2 m component of dip slip in 1872 thus three 1872 type earthquakes could have created the scarp this number of events is also indicated by desert varnish patterns on boulders in the fault scarp by scarp morphology and by sediments near the fault horizontal offset of a relict channel on the fan is 12 to 18 m 3 earthquakes horizontal offset of a younger debris flow is 10 to 12 m apparently 2 earthquakes average horizontal offset for each earthquake including that of 1872 is 4 to 6 m the age of the fan surface is bracketed by a 21 ka shoreline of former lake owens and by the time of abandonment of the fan about 10 ka an average recurrence interval for 3 earthquakes is 5 000 to 10 500 yr the average recurrence interval combined with the average oblique offset for each event of 4 3 to 6 3 m gives an average late quaternary slip rate of 0 4 to 1 3 mm yr for the lone pine fault if we add the average horizontal slip component for the lone pine fault to the 1872 horizontal slip reported for the adjacent main owens valley trace of 2 7 to 4 9 m the combined 1872 horizontal slip component for the owens valley fault zone is approximately between 7 and 11 m a large value the associated horizontal slip rate for the owens vallev fault zone is 0 7 to 2 2 mm yr

two day wave observations of uars microwave limb sounder mesospheric water vapor and temperature 1 a two day wave disturbance is observed in the mesospheric temperature and water vapor on the basis of new version data from the upper atmosphere research satellite microwave limb sounder using two data segments during the austral summers january february of 1992 and 1993 and the asynoptic mapping method a strong wave signal is identified as having zonal wave number 3 and a westward period of about 2 1 days the wave amplitudes are located near the core of the summer easterly jet with strongest wave amplitudes as large as 11 k and 0 35 part per million by volume near the mesopause the temperature and water vapor wave strengths are highly correlated in time but their peaks are almost longitudinally out of phase poleward heat flux associated with upward wave energy propagation in the southern hemisphere points to baroclinic instability as the cause for the wave appearance a growing wave signature in water vapor is observed in regions of strong meridional gradient of water vapor near the mesopause wave breaking is suggested as moist polar air is displaced into the much drier subtropics and wave amplitude decays

southern hemisphere pmse where are they we report a surprising absence of pmse polar mesospheric summer echoes in vhf radar observations of the southern summer high latitude mesosphere our observations cover about twenty days during january february 1993 from king george island antarctica

the importance of earthquake induced landslides to long term slope erosion and slope failure hazards in seismically active regions abstract this paper describes a general method for determining the amount of earthquake induced landsliding that occurs in a seismically active region over time this determination can be used as a quantitative measure of the long term hazard from seismically triggered landslides as well as a measure of the importance of this process to regional slope erosion rates and landscape evolution the method uses data from historical earthquakes to relate total volume of landslide material dislodged by an earthquake to the magnitude m and seismic moment m0 of the earthquake from worldwide data a linear regression relation between landslide volume v and m0 is determined as v m0 1018 9 0 13 where v is measured in m3 and m0 is in dyn cm to determine the amount of earthquake generated landsliding over time this relation is combined with data on seismic moment release for a particular region which may be derived from either earthquake history or fault slip data the form of the m0 v relation allows the rate of production of earthquake induced landslides over time to be determined from total rate of seismic moment release without regard to the distribution of individual events thus simplifying and generalizing the determination application of the method to twelve seismically active regions with areas ranging from 13 275 to 2 308 000 km2 shows that erosion rates from earthquake induced landslides vary significantly from region to region of the regions studied the highest rates were determined for the island of hawaii new zealand western new guinea and the san francisco bay region of california significantly lower rates were determined for iran tibet the sierra nevada great basin region of california and central japan for the time period from 715 ad to the present intermediate rates were determined for peru southern california onshore california turkey and central japan for the time period from 1586 ad to the present to determine the relative long term importance of seismically triggered landslides these erosion rates are compared to erosion rates calculated for other slope processes and to rates calculated from fluvial sediment discharge comparisons with other slope processes indicate that earthquake induced landslides are the predominant agents of slope erosion on the island of hawaii in the san francisco bay region and in western new guinea for hawaii the san francisco bay region and sierra nevada great basin region of california the erosion rates calculated for earthquake induced landslides also exceed the regional erosion rates calculated from fluvial sediment discharge

zonal wave numbers of the summertime 2 day planetary wave observed in the mesosphere by eos aura microwave limb sounder 1 recent observations and theoretical work suggest that the 2 day planetary wave in the summertime mesosphere is composed of multiple superposed zonal wave numbers here we use eos aura microwave limb sounder mls temperature data to determine the component zonal wave numbers of the 2 day wave in the mesosphere at latitudes of 70 s to 70 n from 2004 to 2009 we consider the effect of aliasing between different wave numbers and note that significant aliasing can occur and result in spurious signals particularly at high latitudes in winter the seasonal evolution of the different wave numbers is investigated and found to be very different between the northern and southern hemispheres in both hemispheres the wave is dominated by westward traveling waves of zonal wave number 3 and 4 w3 and w4 however in the southern hemisphere the wave is dominated by the w3 component but in the northern hemisphere the w3 component is smaller and the w4 component is often of similar or larger amplitude a small amplitude westward traveling zonal wave number 2 w2 wave is also evident in both hemispheres in the northern hemisphere the w2 amplitudes never exceed 3 k the w3 amplitudes can reach 3 5 k and the w4 can be the largest component reaching amplitudes of 4 k in the southern hemisphere the w2 amplitudes can reach up to 3 5 k the w3 amplitudes can be much larger reaching 12 k and the w4 amplitudes are smaller than in the northern hemisphere in 4 out of 5 years not exceeding 3 k the northern hemisphere w4 can reach large amplitudes in august when the w3 is small which means that the late summer northern hemisphere quasi 2 day wave is usually a w4 oscillation rather than the familiar w3 in contrast in the southern hemisphere the w3 is often larger than the w4 around the summer solstice and there are no episodes observed where the wave becomes dominated by the w4 for an extended period of time a high degree of interannual variability is evident particularly in the southern hemisphere where the w3 peak amplitudes vary from 12 k in january 2006 to 3 k in january 2009 the height latitude structure of the w4 suggests that this wave is a 4 0 rossby gravity wave

properties of the quasi 16 day wave derived from eos mls observations 1 this paper describes the use of eos microwave limb sounder mls data to observe the field of traveling planetary waves with quasi 16 day periods this study utilizes mls v2 2 temperature and geopotential data between 1 january 2005 and 31 december 2008 in the range 316 hpa to 0 001 hpa approximately 8 to 97 km to examine these waves analysis demonstrates that the quasi 16 day wavefield is made up of a number of components with westward and eastward propagating s 1 and s 2 waves generally dominant in the northern hemisphere the westward and eastward propagating s 1 waves have similar magnitudes and are larger than the other modes while in the southern hemisphere the eastward propagating s 1 and s 2 waves are larger than the westward propagating wave modes all of the modes examined display strong seasonal patterns in the temperature amplitude significant variability in the wave activity from year to year and the presence of strong pulse like patterns in the activity all of the modes also display large median temperature amplitudes poleward of 40 degrees in both hemispheres our analysis also demonstrates that the variability in winter from year to year is larger in the northern hemisphere than the southern hemisphere detailed study also suggests that the exclusion of waves from regions of negative refractive index squared likely forms much of the seasonal pattern observed thus regions of strong westward wind speeds effectively exclude vertically propagating waves as expected from theory the reflection and absorption of waves associated with critical lines is also likely to explain the frequent occurrence of standing wave patterns in the eos mls temperature observations this study highlights the potential of mls observations for observing waves from the upper troposphere to the lower mesosphere

alluvial fan and catchment initiation by rock avalanching owens valley california abstract the north long john alluvial fan of the inyo mountains piedmont owens valley ca was catastrophically initiated by a prehistoric early holocene rock avalanche this avalanche resulted from the collapse and disintegration of the central part of a 1 1 2 0 km range front bedrock facet comprising the divide between the catchments of two large adjoining alluvial fans failure rapidly produced and transferred 25 million m 3 of new sediment to the piedmont where it was deposited in the trough between two coalesced fans these deposits are of unstratified angular muddy bouldery and cobbly pebble gravel present in a u shaped form this form consists of lateral levees 10 to 60 m tall that lead 1 6 km from the range front to a 108 m high distal snout the avalanche sediment comprise the initial platform for and still dominate the nascent north long john fan rock avalanche failure also created a 100 m deep concave scar in the range front that now serves as the fan catchment the slopes of this catchment are mantled by colluvial sediment generated from intense shear along the avalanche detachment surface thus the avalanche served as an alluvial fan starter kit by building the fan platform and by creating a range front catchment lined with sediment because of this unique and recent origin the north long john fan and its catchment are in an early stage of development lacking features such as old surfaces and a well developed drainage net typical of the older adjoining alluvial fans and catchments post avalanche fan activity has been dominated by the deposition of 4 million m 3 of sediment by debris flows these flows including one in 1984 were instigated by the concentration of flashy thunderstorm precipitation across the colluvium of the nascent catchment debris flows have built a conical tract that extends 1 km from the fan apex and partially buries the older avalanche deposits the debris flow tract consists of muddy pebbly cobbly boulder gravel in levees 50 200 cm tall in the steep 12 16 upper segment and boulder free lobes in the lower sloping 5 distal segment this tract terminates in a pond behind the avalanche snout where recessional debris flow pebbly mud has been trapped this pond eventually filled and was breached by a deep channel that now transects the snout of the rock avalanche a second debris flow tract 300 m in radius has prograded outward from the end of the avalanche bypass channel the facies of this tract are identical to those of the proximal fan an abundance of colluvial sediment mantling the steep slopes of the catchment indicates that the north long john fan will continue to enlarge by thunderstorm induced debris flows

an eastward propagating two day wave evidence for nonlinear planetary wave and tidal coupling in the mesosphere and lower thermosphere 1 temperature observations from the saber instrument on the timed spacecraft are used to investigate the structure and evolution of an eastward propagating zonal wavenumber 2 disturbance with a period near two days this oscillation obtains a maximum amplitude of nearly 10 k in the southern hemisphere mid latitudes during late january the timing and location of this planetary wave is coincident with the regular quasi two day wave intensification that occurs annually in late january the period wavenumber and spatial structure of the eastward propagating two day wave are consistent with a wave that results from a nonlinear interaction between the quasi two day wave and the migrating diurnal tide the existence of an eastward propagating wave with a period near two days coincident with the westward propagating two day wave will have an impact on the interpretation of ground based observations analysis of the saber temperature observations are utilized to determine the structure and evolution of both this eastward propagating two day wave and the classic westward propagating zonal wavenumber 3 quasi two day wave during january 2005

low latitude 2 day planetary wave impact on austral polar mesopause temperatures revealed by a january diminution in pmse above davis antarctica 1 a new characteristic of the austral summer polar mesopause as revealed by ground based radar and satellite temperature measurements is reported that is linked to inter annual variability of the low latitude easterly wind jet four consecutive seasons of polar mesosphere summer echoes pmse and mesosphere temperature observations above davis antarctica 68 6 s show a mid january diminution in pmse occurrence rate that coincides with a minor mesopause warming of several degrees spectral analyses of pmse aura microwave limb sounder mls temperatures and radar meridional winds show the presence of 4 5 day planetary waves pws throughout the austral summer in the polar upper mesosphere together with enhanced 2 day pw activity from mid january to mid february analysis of mls temperatures show that the 2 day pws have zonal wavenumbers s with both westward s 2 3 and eastward s 2 3 components although displaying some inter annual variation in the peak onset time the mid january mesopause warming coincides with a weakening of the equatorward meridional wind above davis and enhancement of low latitude 2 day pw activity

facies and depositional model of alluvial fan dominated by episodic flood events in arid conditions an example from the quaternary poplar fan north western china

recent debris flow processes and resultant form and facies of the dolomite alluvial fan owens valley california abstract a multiphase debris flow triggered by an afternoon thunderstorm was deposited 22 august 1984 on the dolomite alluvial fan of owens valley california two tracts 10 300 cm thick accumulated during this event together covering 68 000 m2 26 of the fan with 50 000 m3 of sediment both tracts consist of numerous paired boulder rich levees 100 300 cm high on the proximal fan and multiple attached lobes 20 100 cm thick on the distal fan each levee lobe pathway was built by an individual surge with flow path switching caused by clogging of the frontal bouldery snout of the ensuing surge the levees consist of clast supported to matrix supported muddy pebbly cobbly boulder gravel displaying a well developed radially aligned a axis clast fabric the lobes mostly consist of matrix supported muddy pebbly cobble gravel the clast supported lobe margins are enriched in cobbles displaying a strongly preferred slope parallel a axis fabric along the sides that changes to a slope perpendicular fabric at the snout the distal ends of most of the clast rich lobes are overlain and offlapped by clast poor debris flow lobes of granular mud 10 30 cm thick the central zones of the levees and most lobes were surficially washed by recessional stage water flows that moved winnowed granules sand and mud off the fan the radial change from levees in the proximal fan to lobes distally is morphologically expressed as two intersecting slope segments the upper one sloping 9 12 and the lower one 3 5 this direct relationship between the constituent forms and slope values also is characteristic of pre 1984 deposits suggesting that the 1984 event is typical of the primary processes constructing the dolomite fan the pronounced radial change from levees to lobes and its manifestation as a slope inflection was caused by the selective loss on the upper fan of most of the boulders from the passing debris flow surges boulders were sorted from the surges because of their greater buoyancy which caused them to be preferentially concentrated in the part of the flow that subsequently was sheared off as levees this selective boulder removal depleted the flow of the clasts that provided lateral support facilitating flow expansion and the onset of lobe development thus the resultant facies assemblage is a function of the specific sediment grain size suite available in the catchment colluvium and the transport characteristics of this mix when transformed into a debris flow by the rapid addition of heavy rainfall during infrequent thunderstorms

differentiating the effect of episodic tectonism and eustatic sea level fluctuations in foreland basins filled by alluvial fans and axial deltaic systems insights from a three dimensional stratigraphic forward model many studies of foreland basins have recognized a hierarchical organization in the stacking of sequences deposited by axial deltaic and alluvial fan systems the hierarchy is often explained in terms of the competing control of eustasy and pulsed tectonic subsidence and the different frequencies at which these processes operate unravelling the relative contributions of tectonic and eustatic controls on the sequence stacking pattern is a fundamental question in foreland basin analysis yet this is difficult because of the lack of independent stratigraphic evidence in this study a three dimensional numerical model is presented which aids in the interpretation of alluvial successions in foreland basins filled by transverse and axial depositional systems under conditions of variable tectonism and eustatic sea level change the tectono sedimentary model is capable of simulating the hierarchical stratigraphic response to both eustatic and tectonic forcing and is of higher resolution than previous models of foreland basin filling numerical results indicate that the onset of tectonic activity is reflected by rapid retrogradation of both depositional systems and by widespread flooding and onlap of carbonate sediments syntectonic fluvial patterns on the axial deltaic plain are dominated by bifurcating channels swiftly relocating in response to the general rise in relative sea level induced by flexural subsidence the resulting surface morphology of the axial delta is convex upwards syntectonic eustatic sea level fluctuations result in parasequence scale packages of retrograding and prograding fan and delta sediments bounded by minor flooding surfaces and type 2 sequence boundaries incised channels are rare within the syntectonic parasequences and are formed only during phases of tectonic quiescence when eustatic falls are no longer compensated by the subsidence component in the rise in relative sea level suites of amalgamating axial channels corresponding to multiple eustatic falls delineate the resulting type 1 unconformities coarse grained incised channel fills are found in the zone between the alluvial fan fringes and the convex upward body of the axial delta as the axial streams tend to migrate towards this zone of maximum accommodation

lidar observations of persistent gravity waves with periods of 3 10 h in the antarctic middle and upper atmosphere at mcmurdo 77 83 s 166 67 e persistent dominant and large amplitude gravity waves with 3 10 h periods and vertical wavelengths 20 30 km are observed in temperatures from the stratosphere to lower thermosphere with an fe boltzmann lidar at mcmurdo antarctica these waves exhibit characteristics of inertia gravity waves in case studies yet they are extremely persistent and have been present during every lidar observation we characterize these 3 10 h waves in the mesosphere and lower thermosphere using lidar temperature data in june from 2011 to 2015 a new method is applied to identify the major wave events from every lidar run longer than 12 h a continuous 65 h lidar run on 28 30 june 2014 exhibits a 7 5 h wave spanning 60 h and 6 5 h and 3 4 h waves spanning 40 and 45 h respectively over the course of 5 years 323 h of data in june reveal that the major wave periods occur in several groups centered from 3 5 to 7 5 h with vertical phase speeds of 0 8 2 m s these 3 10 h waves possess more than half of the spectral energy for 93 of the time a rigorous prewhitening postcoloring technique is introduced for frequency power spectra investigation the resulting spectral slopes are unusually steep 2 7 below 100 km but gradually become shallower with increasing altitude reaching about 1 6 at 110 km two dimensional fast fourier transform spectra confirm that these waves have a uniform dominant vertical wavelength of 20 30 km across periods of 3 5 10 h these statistical features shed light on the wave source and pave the way for future research

gis analysis of depositional slope change at alluvial fan toes in japan and the american southwest abstract slope change at alluvial fan toes provides a clue to understanding differences between alluvial fans and other depositional landforms this paper analyses topographic data for 430 alluvial fans and their adjacent lowlands in japan and the american southwest asw typical humid and arid regions with abundant alluvial fans arcs showing fan toes were identified and representative areas above and below each arc were then delineated based on a gis buffer analysis the mean slope of the area above sa and below the fan toe sb and the ratio of sa to sb rs were computed overall fan slope so total fan length l and angle of the fan apex af were also measured relationships among these morphometric parameters reflect differences in climate and sedimentary processes fans in the asw tend to have straight profiles with similar values for sa and so indicating that fan gradients from deposition resulted from low frequency high magnitude storms have been preserved well under an arid climate higher rs values result from good preservation of both steep fan surfaces and gentle adjacent lowlands which is also ascribable to infrequent sediment redistribution in japan sa tends to be smaller than so and rs is often close to unity reflecting frequent sediment redistribution on fans and across fan toes under a humid climate rs in both the regions tends to converge into unity with increasing l longer alluvial fans are more strongly dominated by fluvial processes than by mass flows especially at their toes longer fans also tend to have small af leading to fluvial processes similar to those on floodplains sediment re mobilisation at the toes of such fans is more frequent resulting in smaller differences between sa and sb

first southern hemisphere common volume measurements of pmc and pmse 1 using rayleigh lidar and mesosphere stratosphere troposphere radar at davis antarctica 68 6 s during the 2005 2006 austral summer we obtained the first southern hemisphere common volume measurements of polar mesospheric clouds pmc and polar mesosphere summer echoes pmse pmc were observed with 6 probability during 349 hours of lidar observations pmse were simultaneously observed during 70 of the pmc events the mean centroid altitudes of simultaneous pmc and pmse were 83 97 0 10 km and 85 31 0 14 km respectively the altitude difference 1 3 km is comparable to earlier boreal common volume measurements both phenomena show clear diurnal variations in altitude and occurrence pmc had a unimodal local time occurrence distribution which peaked 4 6 hours after solar midnight pmse were most prevalent at this time but had a secondary occurrence peak 6 hours after solar noon when pmc were absent we explain the altitude time distributions of pmc and pmse in terms of the thermal structure of the mesopause region determined using measurements from the aura satellite