combining local and remote infrasound recordings from the 2009 redoubt volcano eruption abstract the explosive phase of the 2009 redoubt volcano eruption produced predominantly short duration high amplitude infrasound signals recorded up to 4500 km away all 19 numbered explosive events were recorded at a local microphone dfr 12 km as well as at an infrasound array in fairbanks alaska i53us 547 km most with high signal to noise ratios the local microphone provides an estimate of the source parameters and comparison between the two datasets allows the unique opportunity to evaluate acoustic source term estimation at a remote array high waveform similarity between dfr and i53us occurs during much of the explosive phase due to strong stratospheric ducting permitting accurate source constraints inferred from i53us data cross correlation analysis after applying a hilbert transform to the i53us data shows how the acoustic energy has passed through a single caustic as predicted by ray theory similar to previous studies significant low frequency infrasound from redoubt recorded at i53us is coincident with high altitude ash emissions the largest events also produced considerable energy at greater than 50 s periods likely related to the initial oscillations of the volcanic plume or jet many of the explosive events have emergent onsets somewhat unusual for explosive short duration eruptions comparison of the satellite derived so2 emissions with the relative amount of acoustic energy at i53us shows a very high statistically significant correlation this study reiterates the utility of using remote infrasound arrays for detection of hazardous emissions and characterization of large volcanic eruptions and demonstrates how under typical meteorological conditions remote infrasound arrays can provide an accurate representation of the acoustic source

space geodetic tools provide early warnings for earthquakes and volcanic eruptions development of space geodetic techniques such as global navigation satellite system and synthetic aperture radar in last few decades allows us to monitor deformation of earth s surface in unprecedented spatial and temporal resolution these observations combined with fast data transmission and quick data processing enable us to quickly detect and locate earthquakes and volcanic eruptions and assess potential hazards such as strong earthquake shaking tsunamis and volcanic eruptions these techniques thus are key parts of early warning systems help identify some hazards before a cataclysmic event and improve the response to the consequent damage

basin development and syntectonic sedimentation associated with kinematically coupled strike slip and detachment faulting southern nevada a previously unrecognized 12 10 ma clastic sequence is distributed widely south of the las vegas valley shear zone and north of lake mead in southern nevada structural and stratigraphic evidence from these sedimentary and associated volcanic rocks suggests that basin development was kinematically related to movement along the las vegas valley shear zone major movement along the nearby saddle island detachment also occurred within this time interval we suggest that spatially and temporally related basin development sedimentation and stratal tilting reflect kinematically coupled movement along a combined las vegas valley shear zone saddle island detachment fault system

geodetic observations during the 2009 eruption of redoubt volcano alaska abstract in march 2009 redoubt volcano about 160 km to the sw of anchorage alaska began its most recent explosive eruption deformation induced by this event was recorded by a gps campaign network consisting of 14 benchmarks which had been established in 1991 after the previous eruption the network was partially reoccupied in 2001 and 2008 and no volcanic deformation was detected during that period in response to precursory unrest starting in january 2009 the alaska volcano observatory temporarily deployed continuously recording gps instruments at four of the campaign benchmarks only days before the onset of explosive activity in march 2009 the only gps instrument recording continuously during the months prior to the eruption was the plate boundary observatory pbo station ac17 about 28 km northeast of the volcano s summit data from this station reveals subtle motion radially outward from the volcano beginning as early as may 2008 which reversed with the onset of explosive activity using simple analytical models we link the precursory activity to a point source intrusion of 0 0194 0 03400 0092 km3 in volume at 13 50 17 3310 17 km below sea level bsl superscripts and subscripts refer to upper and lower ends of confidence intervals at the 95 level during the explosive phase about 0 05 0 10 028 km3 of magma was evacuated from a prolate spheroid with its centroid at 9 17 15 176 92 km bsl a semimajor axis of 4 50 10 001 25 km length and a semi minor axis of 0 475 4 00 3 km the effusive activity is inferred to come from the same source decreasing in volume by 0 0167 0 02280 0106 km3 including observations from seismology and petrology we hypothesize a mid crustal two reservoir system with material sourced from 20 km flowing in at about 13 5 km depth and reheating residual material in the proposed spheroid the mixture migrated to shallower depth 2 4 5 km bsl and reheated material there as this residual magma erupted it was replaced by the material from the spheroidal reservoir at 7 11 5 km depth which renders the shallow source undetectable for geodetic instruments in addition to long term displacements we investigate sub daily kinematic positioning solutions and find that large short term positioning offsets correlate with large explosive events spikes in phase residuals plotted along the sky tracks of individual satellites can be related to individual plumes given favorable satellite station geometry which may be of use in volcano monitoring

infrasonic tremor in the diffraction zone 1 volcanic tremor signals recorded by an infrasound array 12 5 km from the active vent of k lauea volcano show clear diurnal amplitude variations and originate from a well defined direction pointing to the active pu u crater complex spectral amplitudes between 0 02 0 3 hz a proxy for wind speed increase when the wind speeds increase during the daytime spectral amplitudes between 0 5 3 hz where infrasonic tremor is concentrated increase when the wind speeds decrease at night power spectrum analysis shows that when ambient noise levels drop infrasonic tremor amplitudes rise array processing confirms this relationship and reveals tremor detections and amplitudes decrease during the day these changes in infrasonic tremor spectral amplitude and coherence are most likely due to diurnal variations in atmospheric boundary layers affecting infrasonic propagation within the diffraction zone recognition of these regional atmospheric patterns is necessary to permit robust infrasonic remote sensing of volcanic processes

modelling facies belt distribution in fan deltas coupling sequence stratigraphy and geostatistics the eocene sant llorenc del munt example ebro foreland basin ne spain abstract the eocene sant llorenc del munt fan delta complex developed in the ebro foreland basin the stratigraphy of this succession about 1000 m thick has been described as made up of several transgressive regressive composite sequences each composed of a stack of fundamental sequences in turn made up of a transgressive systems tract and an overlying regressive systems tract systems tracts are composed of several facies belts proximal alluvial fan distal alluvial fan fan delta front carbonate platform and fan delta slope and prodelta a 3d facies model of a 130 m thick stratigraphic succession was built using outcrop data from one of the composite sequences the modelling followed a hierarchical approach a deterministic method was used to reconstruct the surfaces bounding fundamental sequences and their constituent systems tracts data input was outcrop traces digitized on photorealistic terrain models the stacking trend and interfingering of adjacent facies belts within each systems tract was added by means of a geostatistical algorithm and was conditioned to measured stratigraphic logs the analysis of the resultant 3d facies distributions allows revising the architectural interpretation of the studied interval leading to the conclusion that the observed arrangements are accommodation not supply driven furthermore the 3d models were flow simulated in two injector producer scenarios up depositional and down depositional dip waterflooding flow simulation results show that the depositional architecture of the studied succession controls potential recovery efficiencies in that a considerable proportion of moveable oil is trapped at the dead ends in depositional pinch outs of the main potential reservoir fan delta front deposits also that up dip waterflooding predicts better recovery efficiencies than down dip the dataset methods and results herein make the sant llorenc del munt complex a ready for application analogue for marine transitional reservoirs

detection of plumes at redoubt and etna volcanoes using the gps snr method abstract detection and characterization of volcanic eruptions is important both for public health and aircraft safety a variety of ground sensors are used to monitor volcanic eruptions data from these ground sensors are subsequently incorporated into models that predict the movement of ash here a method to detect volcanic plumes using gps signals is described rather than carrier phase data used by geodesists the method takes advantage of attenuations in signal to noise ratio snr data two datasets are evaluated the 2009 redoubt volcano eruptions and the 2013 2015 eruptions at mt etna snr based eruption durations are compared with previously published seismic infrasonic and radar studies at redoubt volcano snr based plume detections from mt etna are compared with l band radar and tremor observations to place these snr observations from redoubt and etna in context a model of the propagation of gps signals through both water water vapor and tephra is developed neither water nor fine ash particles will produce the observed attenuation of gps signals while scattering caused by particles 1 cm in diameter potentially could

strike slip faulting and block rotation in the lake mead fault system strike slip faults in the basin and range province have often been considered passive boundaries between differentially extended domains of tilted normal faults and are thus considered secondary in accommodating regional horizontal deformation paleomagnotic investigation of late miocene age volcanic rocks displaced by the left lateral fault system of lake mead nevada shows 1 that these rocks have not been affected by significant structural tilt the difference between observed and expected inclinations being only 0 6 14 9 and 2 a significant horizontal counterclockwise rotation of 29 4 8 5 about a vertical axis this rotation was accommodated by slip on northwest trending right lateral strike slip faults this implies significant west northwest elongation results of the investigation indicate that strike slip faulting is the primary process accommodating crustal deformation along the lake mead fault system and that tilting in response to normal faulting is secondary

the 2001 adana landslide and its destructive effects turkey the current study deals with a catastrophic landslide that occurred due to heavy rainfall in adana southern turkey in 2001 the research area which is one of the largest populated districts in adana and one of the most tropical places between the middle east and southern europe has about 25 000 people on the basis of geological and geotechnical surveys the landslide phenomena and the effects of landslide are examined to understand the slide mechanism of the landslide ground reconnaissance laboratory and in situ tests are conducted it is observed that the clayey and silty layers of the site are heavily saturated due to extreme rainfall in winter and consequently sheared the landslide consists of a block sliding in the upper portions and a debris flow soil flow component around the margins of the sliding blocks in the middle parts and at the toe although there was no loss of human life it has caused significant economic losses besides it is determined that if precautions are not taken around the landslide area larger landslides could definitely occur in the future

tertiary uplift and shortening in the basin and range the echo hills southeastern nevada the echo hills is a distinctive area of tectonic uplift and shortening located at a right step in the left lateral bitter spring valley fault of the late tertiary lake mead fault system nevada the fundamental internal structure of the echo hills is an asymmetric anticline disrupted by reverse and oblique faulting an analysis of the stress distribution within the stepover indicates that the interaction between the two segments of the bitter spring valley fault is responsible for the compressive deformation and structural uplift in the echo hills given the number of strike slip faults in the basin and range similar examples of tertiary uplift and shortening probably occur elsewhere within the province

jurassic deep water fans in the neo tethys ocean the kashafrud formation of the kopet dagh basin iran abstract the middle jurassic kashafrud formation of northeast iran was deposited in the kopet dagh basin linked to the neo tethys ocean the 2 km thick succession commences with fluvio marine boulder conglomerates that occupy bedrock valleys but the bulk of the formation comprises a deep water succession of interbedded sandstone and mudstone packages with trace fossils and sparse ammonites neogene collisional events deformed the strata to create the kopet dagh mountains the deep water succession represents channel lobe systems and associated levees and overbank areas on slope to basin floor fans northward paleoflow suggests that rivers drained uplands along the paleo tethys suture zone forming fan deltas on a narrow shelf with associated sediment transport to deeper water coarse sands extrabasinal pebbles and plant fragments are present throughout the formation and a thick boulder conglomerate unit lies within the turbidite succession these observations suggest proximity to terrestrial sources throughout deposition sandstone packages are mainly less than 10 m thick maximum 84 m and numerous lensoid packages of thick bedded sandstone tens of meters thick and up to 200 m wide represent submarine channel fills thick bedded lenses and sheets show a relatively narrow range of paleoflow direction and represent major submarine conduits whereas the more varied paleoflow direction of thin bedded packages suggests that many were deposited on levees the presence in the kashafrud formation of potential source rocks in the form of organic rich mudstones and abundant plant fragments suggests that the formation may have contributed to hydrocarbon fields within overlying formations sandstone sheets and channel fills could form local reservoirs

geophysical constraints on the location and geometry of the las vegas valley shear zone nevada we model the basin configuration beneath las vegas valley nevada on the basis of gravity drillhole and seismic reflection data we locate and characterize the various strands of the las vegas valley shear zone lvvsz by variations in basin thickness beneath the valley the pre tertiary bedrock surface is complex with subbasins buried beneath the flat alluvial surface of the valley we suggest that these basins are formed from transtensional strain subbasins elongated n70 w and n50 w are interpreted as strike slip basins the deepest subbasin is 5 km west of frenchman mountain and strikes n40 e this basin probably formed by combined movement on nonparallel strands of the lvvsz and an earlier episode of normal faulting the basin thickness map constrains the minimum depth of the inferred detachment fault beneath las vegas valley to at least 4 km seismic reflection data do not image a detachment fault in the upper 10 km beneath las vegas valley our results also illustrate the utility of gravity in determining basinal structures and providing a three dimensional perspective in areas with limited seismic reflection control

structural framework and deformation history of the western cyprus arc abstract an extensive grid of high resolution multichannel seismic reflection profiles complemented with wider spaced deep penetrating industry seismic profiles revealed that the pre messinian miocene structural architecture of the antalya basin and its southwestern extension into the florence rise is characterized by a very prominent broadly northwest southeast striking and largely southwest verging fold thrust belt with occasional northeast verging backthrusts during the messinian a number of prominent thrusts remained active however numerous thrusts which were active during the pre messinian miocene became inactive during the uppermost messinian quaternary the stain was partitioned into five broadly northwest southeast trending morphotectonic domains each delineated by a distinctive seafloor morphology a a domain across the inner and western antalya basin is dominated by extensional faults b a domain immediately south of the extensional faults is characterized by contractional structures c a halokinetic zone in southwestern antalya basin north of the foothills of the anaxagoras mountain is characterized by numerous positive flower structures beneath a corrugated seafloor d a domain characterized by fluid escape structures immediately southeast of the halokinetic zone and e a domain across the crestal portion of the florence rise is dominated by prominent inversion structures detailed mapping documented that several of these tectonic domains can be readily correlated with previously mapped tectonic elements in the eastern mediterranean as well as structures mapped across the adjacent landmass the change from ubiquitous pre messinian miocene contraction to partitioned strain of the latest messinian quaternary is likely related to the collision of the eratosthenes with cyprus and the resultant jostling of the tectonic blocks

neogene tectonics and plate convergence in the eastern mediterranean new data from southern turkey data reported here demonstrate that the misis complex of southern turkey comprises a major olistostromic body formed prior to the early miocene and tectonically emplaced upon a structurally imbricated pile of deep and shallow marine sediments of early miocene to pliocene age magmatic rocks forming olistoliths in the misis complex have a back arc geochemical signature and variations in the facies paleoenvironments and paleotransport vectors within the associated sediments provide a record of miocene collisional events in southeast turkey the pseudo accretionary imbrication and structural style of the misis complex are attributed to continued collisional over thrusting but there is evidence within the imbricated stack of late sinistral strike slip faulting that relates to post miocene inception of motion along the east anatolian fault system the new data favor these geodynamic models proposed for the neogene evolution of the northeastern mediterranean that involve oblique convergence and associated strike slip adjustments

late cretaceous paleomagnetism of the east ranges island arc complex kamchatka implications for terrane movements and kinematics of the northwest pacific a campanian lower paleocene island arc complex was sampled for paleomagnetic studies at 12 sites in the east ranges tectonic zone of kamchatka after thermal demagnetization a reversed polarity characteristic remanent magnetization chrm was isolated from most volcanoclastic and basaltic units as well as from lava debris from intraformational conglomerates the fold and conglomerate tests are positive and the chrm in the studied rocks is likely primary the formation mean inclination of 66 3 3 7 corresponds to a paleolatitude of 48 7 5 0 n which is about 20 lower than the late cretaceous north american reference values because northward displacement of the studied terrane is indicated by the paleomagnetic data we examine several models of intraoceanic transport with the pacific and or kula plates and coastwise transport after terrane accretion far to the south of the present day position of kamchatka our preferred interpretation is that the studied island arc complex accumulated at about 83 79 ma the island arc to which the studied terrane had originally belonged was active between this time and 65 60 ma according to geological data the docking time nearly coincided with cessation of volcanic activity and northward movement of the island arc took place simultaneously with the volcanic activity the absolute motion of a subduction zone should have the same direction as the overriding plate therefore the subduction zone related to the east ranges island arc is inferred to have moved northward with the kula plate or with the kula and pacific plates successively consuming either the oceanic periphery of a continental plate or some unknown minor oceanic plate this process went on until 65 55 ma when the island arc and related subduction zone approached the continental margin and became extinct the proposed models also place additional constraints on kinematics of the kula pacific transform plate boundary

local seismic and infrasound observations of the 2009 explosive eruptions of redoubt volcano alaska article i nfo local seismic and infrasound data are used to characterize the march april 2009 eruptions of redoubt volca no alaska data are from a network of ten seismic stations ranging from 2 6 to 21 km from the vent and a single infrasound sensor 12 2 km from the vent measurements were made for more than 30 explosive erup tions including the 19 numbered events that were identified during the eruption response more than 30 smaller explosions were also identified measured parameters include onset time duration reduced dis placement dr pressure seismic energy and acoustic energy results were compared with complementary gas and lightning data based on ratios of pressure to dr and acoustic to seismic energy we find that the initial group of explosive eruptions on 23 24 march was relatively stronger seismically and included the four highest dr values we infer that these represent vent enlargement or stronger coupling between the magma and wall rocks one event at 12 31 ut on 23 march had an extremely high pressure of 250 pa for the initial pulse and was likely weakly seismically coupled a second group of explosive eruptions on 27 29 march was relatively stronger acoustically deposits were finer grained and of different lithology with less scoria and more dense clasts these two groups may represent different modes of gas release cumulative acoustic energy as a function of time correlates well with comparable lightning and so2 data suggesting that all three provide insight regarding different factors of gas release for the eruption as a whole the number of events identified depends on criteria measured and depends on the goals of the investigations overall the eruptions were substantially stronger than recent eruptions in alaska with some durations exceeding 1 h and pressures an order of magnitude higher

deformation pattern around the conjoining strike slip fault systems in the basin and range southeast nevada the role of strike slip faulting in basin formation and inversion within the extensional regime of the basin and range strike slip faults create a regional pattern of opposing sense of fault systems the relationship between these faults and other deformational features nearby is enigmatic this paper addresses a diverse assemblage of contractional and extensional structures reflecting local uplift and subsidence respectively at the junction of two large neogene strike slip faults in southeastern nevada the right lateral las vegas valley shear zone and the left lateral bitter spring valley fault of the lake mead fault system first a middle miocene lacustrine carbonate basin the bitter ridge lovell wash carbonate basin formed north of the strike slip faults second the lacustrine basin inverted locally while sediments accumulated south of the strike slip faults third the study area was deformed by north northeast trending high angle oblique faults with normal and left slip components the results both from field observations and numerical modeling of the intersecting strike slip faults show that the las vegas valley shear zone and the bitter spring valley fault may have produced the basin in the north and its intense contractional deformation as well as the southward shift of deposition during the inversion event we conclude that conjoining strike slip fault systems can promote localized vertical tectonics and lead to basin formation and uplift right next to each other subsequent inversion of the earlier basinal deposits however requires a reversal in the sense of slip across the las vegas valley shear zone and a change in the regional stress system

miocene recent evolution of the western antalya basin and its linkage with the isparta angle eastern mediterranean abstract interpretation of 9500 km of multichannel seismic reflection profiles showed the presence of two major tectonic histories in western antalya basin spanning from the miocene or older to the pliocene quaternary a prominent fold thrust belt affects the miocene succession in the offshore the thrusts swing from a nw se strike with sw vergence in the northeast of the mapped area to a more northerly strike with westerly vergence at the western shelf edge of the deep basin the miocene deformation appears to continue offshore from the westerly directed thrusting seen onshore that characterizes the eastern edge of the isparta angle the contraction is consistent with the counterclockwise miocene rotation of the western side of the isparta angle determined from paleomagnetic studies the thrust belt forms the western extremity of the wider regional aksu kyrenia misis oroclinal culmination the tectonic activity experienced a period of relative quiescence across the western antalya basin during the messinian a major kinematic change occurred in the pliocene when the regional strain was partitioned into three spatially localized tectonic domains an extensional domain confined to the pliocene quaternary unit 1 occupied the northeastern portion of the study area a predominantly extensional domain with a few re activated pre existing miocene contractional structures occupied the southern and central portion of the study area and an extensional and or transtensional domain occupied the continental shelf and slope in the westernmost antalya basin these complexities relate to strike slip motions as the crustal block within the isparta angle moved northwards relative to the blocks to the north

sounding the plume of the 18 august 2000 eruption of miyakejima volcano japan using gps 1 we processed 79 days of gps data collected at four stations on miyakejima volcano japan before and during its eruption in 2000 this period includes a strong seismic swarm 27 june to 8 july followed by five eruptions 8 and 14 15 july 10 18 and 29 august surface motion is strong during the seismic swarm then remains almost steady during eruptions however during each eruption we found anomalous values of the lc ionosphere free double differences especially on 18 august with a peak of 0 6 cycles i e an apparent 290 mm increase of the satellite station range we cannot explain these anomalies by temporary ground displacements during the events instead we propose that they are due to path delay effects in the hot volcanic plume by adapting a seismic tomography algorithm the refractivity anomaly and the inferred temperature in the plume is mapped in time and space

the pliocene quaternary tectonic evolution of the cilicia and adana basins eastern mediterranean special reference to the development of the kozan fault zone abstract a grid of high resolution multi channel seismic reflection profiles allows the detailed mapping of the kozan fault zone in the cilicia and adana basins the zone is delineated by an arcuate zone consisting of several ene wsw and nne ssw striking closely spaced high angle extensional faults which define an 300 km long and 15 20 km wide lazy s shaped structure along the southeastern fringes of the taurus mountain and along the northwestern margins of the cilicia and adana basins in the cilicia basin the zone consists of several high angle faults which exhibit small dip separations on the m reflector and have tip points situated mainly in the lower and middle portion of the pliocene quaternary succession in the adana basin a family of northeast striking and southeast dipping extensional faults occurs along the western and northwestern margin of the basin the faults cut down with relatively steep dip into the 700 ms thick tortonian and older miocene successions multi channel seismic reflection profiles show that three prominent seismic markers divide the uppermost messinian recent successions in the cilicia and adana basins into three subunits the uppermost messinian lower pliocene subunit 1c between the m and a reflectors the upper pliocene subunit 1b between the a and p reflectors and the quaternary subunit 1a between the p reflector and the seafloor prominent delta lobes are identified in the seismic profiles that are correlated with the ancestral goksu river isopach maps constructed using depth converted seismic reflection profiles show clear temporal and spatial variations of the delta lobes of the goksu river during the latest messinian recent the uppermost messinian lower pliocene delta lobe is situated furthest to the northeast whereas the youngest quaternary lobe is situated furthest to the southwest with 20 35 km displacement along a northeast southwest line which suggests a conservative estimate of 0 43 0 75 cm yr sinistral slip for the kozan fault zone

state of stress and modern deformation of the northern basin and range province constraints on the current stress regime of the actively extending northern basin and range province are provided by deformation data focal mechanisms and fault slip studies hydraulic fracturing in situ stress measurements borehole elongation breakouts analyses and alignment of young volcanic vents the integrated data indicate significant variations both in principal stress orientations and magnitudes an approximately e w least principal stress direction appears to characterize both the eastern and western margins of the basin and range province whereas in the active interior parts of the province extension occurs in response to a least principal stress oriented nw to n60 w the contrast in stress orientations between the province boundaries and in the interior suggests that along the margins the least principal stress direction may be locally controlled by the generally northerly trending profound lithospheric discontinuities associated with these margins active deformation along the southeastern and western province margins is characterized by a combination of strike slip and normal faulting focal mechanisms along northeastern province margin wasatch front and in central nevada indicate a combination of normal and oblique normal faulting temporal regional and depth dependent variations in the relative magnitudes of the vertical and maximum horizontal stresses can explain much of the observed variations in deformation styles however some depth variation in faulting style inferred from focal mechanisms may be apparent and simply a function of the attitude of fault planes being reactivated evidence for significant temporal variation or multiple cycles of variation in relative stress magnitude comes from the sierran front basin and range boundary region where recent earthquakes are predominantly strike slip whereas the profound relative vertical relief across the sierra frontal fault zone in the last 9 10 m y implies a normal faulting stress regime using the best data on stress orientation relative stress magnitudes are constrained from slip vectors of major earthquakes and young fault displacements analysis of well constrained slip vectors in the owens valley california area indicate that large temporal variations in the magnitude of the approximately n s oriented maximum horizontal stress are required to explain dominantly dip slip and strike slip offsets on subparallel faults similar faulting relations are observed throughout much of the boundary zone between the basin and range sierra nevada including the walker lane belt along the eastern province margin in the wasatch front area in utah available data suggest that the maximum and minimum horizontal stresses may be approximately equal at depths of 4 5 km earthquake focal mechanisms in this area suggest more variability in relative magnitude of the two horizontal stresses with depth furthermore superimposed sets of young fault striae along a segment of the wasatch fault also indicate temporal variations of relative stress magnitudes sources of regional and temporal variations in the stress field may be linked to variable shear tractions applied to the base of the brittle crust related to intrusion thermally induced flow and the influence of the san andreas plate boundary although difficult to date accurately the fault slip data suggest that the temporal variations in relative magnitudes stress may occur on the time scale of both a single major earthquake cycle 1000 5000 years and multiple earthquake cycles 10 000 years

sedimentary architecture of a canyon style fairway feeding a deep water clastic system the miocene cingoz formation southern turkey significance for reservoir characterisation and modelling abstract the sedimentary architecture of a submarine canyon fill supplying sediment to a deep water fan system in the adana basin southern turkey is described and quantified the canyon is at least 9 km long 3 4 km wide asymmetric in cross section and has an exposed fill 360 m thick consisting of sands and gravels deposited in sheets across the entire width of the canyon normal graded and nongraded pebbly sandstones reflecting deposition from both waning and waxing high density turbidity currents dominate these deposits facies are identified and correlated between closely spaced sedimentary logs a hierarchy of bedding scales is recognised ranging from individual beds and their sedimentary structures through 3 21 m thick packages of beds to 100 m thick major units this hierarchy provides the framework for computer generated 3d models where sandstone bodies and facies are stochastically modelled to provide a better understanding of the internal sedimentary architecture within similar types of canyons in subsurface or in areas of poor exposure

detecting complex eruption sequence and directionality from high rate geodetic observations the august 6 2012 te maari eruption tongariro new zealand abstract the tongariro te maari crater new zealand erupted for the first time in over 80 years on august 6 2012 because it occurred at night the short lived eruption prevented direct visual observations hence presenting some challenges for understanding the complex eruptive sequence and reach of the various explosions using 1 hz global positioning system gps data from the local volcano monitoring network we computed the gps lc phase residuals and snr data at the time of the eruption and show that several processes successively affected the signal at the closest gps station firstly the signal from one of the satellites shows two successive drops of snr caused by the presence of two distinct dense ash laden plumes near the vent produced successively by the second and last of the main eruption pulses secondly we show that a gas charged debris avalanche and a lateral blast successively entrained hot and or humid air over 3 km away from the vent atop the vgkr gps station while the limited amount of data prevents fully quantitative analyses and estimates of temperature or humidity in the lateral air flow our results document the first recorded detection of a small scale lateral plume by gps technology they highlight the potential of gps data analysis for improving our understanding of eruptive sequences when visual observations are limited

detection of ground motions using high rate gps time series monitoring surface deformation in real time help at planning and protecting infrastructures and populations manage sensitive production i e seveso type and mitigate long term consequences of modifications implemented we present rt shake an algorithm developed to detect ground motions associated with landslides sub surface collapses subsidences earthquakes or rock falls rt shake detects first transient changes in individual gps time series before investigating for spatial correlation s of observations made at neighbouring gps sites and eventually issue a motion warning in order to assess our algorithm on fast seconds to minute large from 1cm to meters and spatially consistent surface motions we use the 1hz geonet gnss network data of the tohoku oki mw9 0 2011 as a test scenario we show the delay of detection of seismic wave arrival by gps records is of 10 seconds with respect to an identical analysis based on strong motion data and this time delay depends on the level of the time variable noise nevertheless based on the analysis of the gps network noise level and ground motion stochastic model we show that rt shake can narrow the range of earthquake magnitude by setting a lower threshold of detected earthquakes to mw6 5 7 if associated with a real time automatic earthquake location system

vertical and lateral organization of a carbonate deep water slope marginal to a submarine fan system miocene southern turkey organization is recognized in the forereef deep water slope submarine fan system of the burdigalian langhian kaplankaya formation a basinwards transition from a prograding shelfal reef complex through forereef talus deep water slope and laterally encroaching bypass deep water clastic system is described although the deep water slope makes up the bulk of the succession considerable thickness variations occur between the reef and deep water clastic complexes these are controlled by sea floor topography carbonate foreslope gradient and degree of mass wasting off the platform and foreslope the vertical and lateral heterogeneity of the kaplankaya deep water slope system is described from a number of localities along a 40 km long and up to 3 km wide exposed section of the northern margin of the miocene adana basin a foreland basin setting resulting from thrust sheet loading from the north during the tauride orogeny detailed field mapping is supplemented with vertical sedimentary logs photomosaics palaeontological and petrological data to investigate stratal variation diagnostic architectural elements controls on slope progradation differential timing of basinward encroachment of the reefal complex and lateral onlap of the deep water clastic system onto the slope three dimensional models are presented showing the vertical and lateral facies associations in different parts of the deep water slope system and provide a basis for architectural prediction of geometry and relative position in such environments

a revised stratigraphic framework for later cenozoic sequences in the northeastern mediterranean region this study describes the lithostratigraphic character of mid cenozoic oligocene pliocene sequences in different parts of the northeastern mediterranean area and offers a detailed stratigraphic correlation for this region the sequences concerned are drawn from the camardi area south central anatolia the adana basin the misis mountains and the kyrenia range northern cyprus and the submerged florence rise west of cyprus the stratigraphic relationships identified here indicate the following a following the middle eocene lutetian regression there was uplift throughout the entire region b episodes of fluvial and lacustrine deposition in intramontane settings ensued in most of this region during the late eocene early miocene interval c following a regionally extensive phase of tectonic compression major marine transgression commenced in the late oligocene in northern cyprus and in the early miocene in adjacent southern turkey with the exception of the ecemi fault zone where continental deposition continued d these oligo miocene transgressive sequences comprise a broadly diachronous complex of both shallow and deeper marine facies including reefal carbonates littoral clastics basinal shales and fan turbidites e deeper marine miocene facies persisted longer in the misis area and in northern cyprus f a regional regression occurred throughout most of the area during the late serravallian to tortonian interval and is marked by the abrupt locally discordant appearance of extensive shallow marine deltaic and fluvial deposits g continued regression in the messinian led to the formation of significant evaporite deposits in the western and southern parts of the region but localized uplift of the misis area is attested by the initial deformation of the neogene rocks there and the absence of messinian sediments from this area h in the pliocene there was extensive emergence of the northern parts of the region interrupted by brief marine incursions the present day drainage pattern was established at this time i marine conditions persisted longer in northern cyprus where emergence occurred only in the latest pliocene

a new way to detect volcanic plumes 1 detection of volcanic plumes especially ash laden ones is important both for public health and aircraft safety a variety of geophysical tools and satellite data are used to monitor volcanic eruptions and to predict the movement of ash however satellite based methods are restricted by time of day and weather while radars are often unavailable because of cost portability here a method is proposed to detect volcanic plumes using gps signal strength data the strengths and limitations of the method are assessed using gps data collected during the 2008 and 2009 eruptions of the okmok and mt redoubt volcanoes plume detections using this gps technique are consistent with independently collected seismic and radar data

the mid cenozoic succession and evolution of the mut basin southern turkey and its regional significance abstract the hitherto poorly known mut basin occupies a position that is critical to our understanding of the later cenozoic history of south central turkey the biostratigraphic and sedimentological study reported here reveals an extended and complex pattern of basin evolution and enables the history of this basin to be compared in detail with that of adjacent south turkish basins the oldest basin fill deposits are demonstrated to be oligocene to earliest miocene in age and comprise alluvial redbeds thick lacustrine deposits and thin lagoonal sediments mainly supplied from northern tauride sources this mainly terrestrial megasequence resulted from an early oligocene phase of crustal extension leading to rapid trap door subsidence and the formation of narrow e w trending troughs this phase was terminated by a minor marine incursion and through reactivation of basement faults during renewed extension in the earliest miocene the overlying miocene succession thus rests with local angular discordance upon tilted and gently deformed oligocene and older rocks subsequent subaerial erosion created an irregular pre burdigalian palaeotopography that strongly influenced the nature thickness and distribution of the early miocene basin fill in palaeotopographic depressions the miocene sequence commences with alluvial fan braidplain and meander belt redbeds formed in river systems that flowed mainly south and southeast these pass up and laterally into more extensive lagoonal and shallow marine mixed clastic carbonate units yielding late burdigalian to early langhian microfaunas marking the inception of the main miocene marine transgression in this area episodic northwards marine advance led to isolation of the northerly source of siliciclastic detritus and resulted in periodic onlap of mid to inner shelf fine grained carbonates with thin clastic intercalations that include isolated coralgal build ups calcarenite mounds and sand waves at the peak of miocene transgression mid serravallian thick reefal limestones were deposited far to the north and also formed on top of basement highs forming the southern and eastern flanks of the basin significant influxes of coarse and fine siliciclastics from the north attest to periodic progradational events that are more conspicuous and protracted in the late serravallian and tortonian however muddy deeper shelf conditions prevailed throughout the middle miocene in the central part of the basin while stronger currents and unstable slopes characterise the constricted marine strait in the southeast of the basin near silifke in terms of their sequential arrangement palaeoenvironmental and tectonic evolution the oligo miocene sediments of the mut basin closely resemble coeval sequences in the adjacent ecemis aktoprak and karsanti northern adana basins and share a similar history involving complex interplay between regional tectonics and eustasism deeper water oligo miocene sequences in the outboard troughs such as the southern adana basin and the kyrenia misis andirin complex yield more subtle signatures of these tectonic and eustatic events the differences between these basins are attributable to the influence of regional kinematic elements generated during the reorganisation of plate boundaries in the northeast mediterranean that followed final suturing of the arabian and anatolide plates in the mid cenozoic

morphology paleogeographic setting and origin of the middle wilcox yoakum canyon texas coastal plain the yoakum canyon is the largest of the gulf coast eocene erosional gorges and is interpreted as a buried submarine channel the canyon can be traced for 67 mi 108 km from the wilcox fault zone which defines the position of the early eocene shelf edge nearly to present outcrop in this paper we expand on previously published descriptions of the canyon and use a more extensive subsurface database decompaction of the canyon shale fill reveals that original depths of the canyon exceeded 3500 ft 1067 m apparent canyon wall slump scarps and a peripheral chaotic zone interpreted as an incipient slump feature are comparable to similar features of the late quaternary mississippi submarine canyon the yoakum canyon formed within the garwood subembayment to the west of and adjacent to the middle wilcox rockdale delta system quantitative mapping of facies adjacent to the yoakum shale indicate the following sequence of events l muddy distal deltaic and shelf facies of the lower middle wilcox subgroup were deposited during a retrogradation 2 a resurgence of progradation deposited upper middle wilcox deltaic facies atop the unconsolidated lower middle wilcox continental margin muds loading the shelf edge and initiating slump failure of the continental margin 3 headward erosion of the canyon across the shelf occurred contemporaneously with a subsidence induced transgression that coincided with a disruption in sediment supply the yoakum canyon was excavated by a combinat on of slumping and current scour 4 the canyon was filled by hemipelagic and prodelta muds of the upper wilcox subgroup

late cenozoic uplift of the amanos mountains and incision of the middle ceyhan river gorge southern turkey ar ar dating of the duzici basalt using the ar ar technique we have obtained the first numerical dates for the pleistocene volcanism along the valley of the river ceyhan in the duzici area of southern turkey in the western foothills of the amanos mountains our six dates indicate a single abrupt episode of volcanism at 270 ka we have identified a staircase of 7 fluvial terraces at altitudes of up to 230 m above the present level of the ceyhan using the disposition of the basalt as an age constraint we assign these terraces to cold climate stages between marine oxygen isotope stages 16 and 2 indicating rates of fluvial incision equated to surface uplift that increase upstream through the western foothills of this mountain range at between 0 25 and 0 4 mm a 1 extrapolation of these uplift rates into the axis of the range suggests that the entire 2300 m of present day relief has developed since the mid pliocene a view that we confirm using numerical modelling since 3 7 ma the amanos mountains have formed a transpressive stepover along the northern part of the dead sea fault zone where crustal shortening is required by the geometry using a physics based technique we have modelled the overall isostatic response to the combination of processes occurring including crustal thickening caused by the shortening erosion caused by orographic precipitation and the resulting outward flow of mobile lower crustal material in order to predict the resulting history of surface uplift this modelling suggests that the effective viscosity of the lower crust in this region is in the range 1 2 1019 pa s consistent with a moho temperature of 590 10 c the latter value being in agreement with heat flow data this modelling shows that the nature of the active crustal deformation is now understood to first order at least in this key locality within the boundary zone between the african and arabian plates the structure and geomorphology of which have been fundamentally misunderstood in the past

origin and trajectory of the frenchman mountain block an extensional allochthon in the basin and range province southern nevada abstract the central basin and range province has provided a natural laboratory for the study of continental extension since the pioneering studies of chester r longwell it is here that large magnitude crustal extension along systems of normal faults was first documented by r ernest anderson estimates of crustal extension in the lake mead extensional domain eastern central basin and range province have been based largely on restoration of displaced blocks most notably the frenchman mountain block the original position of frenchman mountain an allochthonous block that has been translated more than 60 km westward during regional extension has been controversial for more than 2 decades we use correlation of mass wasting deposits with source areas paleozoic stratigraphic characteristics and subunconformity pinchout relations to evaluate previously published models for the original position of the frenchman mountain block and use new evidence to propose a more tightly constrained preextension posi

neogene paleostress changes in the basin and range a case study at hoover dam nevada arizona at hoover dam 40 km southeast of las vegas nevada well exposed highly faulted miocene rocks provide an excellent opportunity to study the paleostress history of a very small area within a region where previous geologic studies indicate clockwise rotation of paleostress and a nearness to a major strike slip fault zone boundary within 0 5 km3 of rock the sense of slip was determined on almost 500 separate faults the fault slip data show internal consistency with respect to lithology size of faults and location within the small area with respect to fault slip however the data represent an in homogeneous mixture of primarily strike slip and dip slip motions from this mixture it is possible to resolve two distinct stress fields with directions of extension that differ by 60 each stress field corresponds to a mixture of strike slip and dip slip faults and thus the orientations of 1 and 2 are not tightly constrained if however the data are first separated into strike slip and dip slip faulting modes and subsequently searched for sub populations that correspond to contrasting paleostress orientations the computations yield tightly constrained tensors that illustrate two distinct stress fields with subhorizontal 3 axes that trend n50 e and n75 w the 1 and 2 axes permutate in two vertical planes that strike n40 w and n15 e because 1 and 2 are close in value relative to 3 these relationships suggest that strike slip and dip slip faulting belong to the same tectonic regime qualitative observations of polyphase slip fault fault offsets and fault bedding geometric relationships when evaluated in the context of changes in 3 orientation and permutations of 1 and 2 provide a basis for a two stage late cenozoic structural evolution at hoover dam these stages are 1 strike slip faulting partly pre tilt and dip slip faulting and associated stratal tilting and 2 mostly post tilt complexly interrelated strike slip oblique slip and dip slip faulting the qualitative evaluations indicate that strike slip and dip slip faulting alternated in time during the second stage of deformation and may have done so during the first these mixed mode movements probably represent stress oscillations in time and space rather than discrete stress reorganizations in contrast the two different orientations of 3 either represent a major clockwise rotation of the stress field or a major counterclockwise rotation of the rocks during the faulting history each alternative is consistent with regional geologic relationships and the choice of which is correct cannot be made within the small area that was studied

high resolution stratigraphy and sedimentary evolution of coarse grained canyon filling turbidites from the upper cretaceous transgressive megasequence campos basin offshore brazil abstract coniacian to lower maastrichtian coarse grained turbidites fill intra slope fault controlled canyons in the campos basin off shore brazil they form part of an upper albian to lower paleocene transgressive succession characterized by onlapping deepening upward sedimentation throughout the eastern brazilian margin in the carapeba and pargo crp pg oil fields the turbidites consist mainly 95 of graded beds without any other sedimentary structures individual beds are up to 12 m thick and are composed of small pebble 2 cm to granule rich sandstones and medium to very coarse sandstones the finer grained portions of these graded beds show better sorting and higher porosity and these characteristics can be recognized in density logs use of 92 density logs calibrated w th 13 cores permitted the mapping of 198 coarse grained turbidites in the crp pg turbidite system the turbidites form eight thinning and fining upward facies successions some bounded by regional unconformities or local erosion surfaces the successions are 27 140 m thick and contain 7 58 turbidites their durations are estimated to be between 0 4 0 9 m y they form 1 12 km wide tabular or linguoid sandstone bodies in which the younger or more distal turbidites become finer grained thinner bedded and more discontinuous upsection and downcanyon the successions are stacked in an overall retrogradatioual pattern for at least 20 km recording the backfilling of the crp pg canyon turbidites in the crp pg area were probably deposited during falls of relative sea level that punctuated the overall transgressive setting of the late cretaceous and early tertiary there is a mismatch between the number of successions eight and the number of time equivalent third order fluctuations of relative sea level four and part of a fifth haq et al 1988 suggesting that eustatic sea level fluctuation was not the dominant control on most of the successions cross sections and isopach maps of the successions do not suggest internal channeling and a channel fill origin for the fining and thinning upward successions seems unlikely we therefore suggest that episodic tectonic reactivation in the uplifted precambrian source area and faulted basin margin led to relatively abr pt increases in the volume of sediment supplied to the head of the canyon across a narrow shelf steady denudation and decreasing supply of sediment led to formation of the fining and thinning upward successions

can we measure snow depth with gps receivers 1 snow is an important component of the climate system and a critical storage component in the hydrologic cycle however in situ observations of snow distribution are sparse and remotely sensed products are imprecise and only available at a coarse spatial scale gps geodesists have long recognized that snow can affect a gps signal but it has not been shown that a gps receiver placed in a standard geodetic orientation can be used to measure snow depth in this paper it is shown that changes in snow depth can be clearly tracked in the corresponding multipath modulation of the gps signal results for two spring 2009 snowstorms in colorado show strong agreement between gps snow depth estimates field measurements and nearby ultrasonic snow depth sensors because there are hundreds of geodetic gps receivers operating in snowy regions of the u s it is possible that gps receivers installed for plate deformation studies surveying and weather monitoring could be used to also estimate snow depth

doppler weather radar observations of the 2009 eruption of redoubt volcano alaska abstract the u s geological survey usgs deployed a transportable doppler c band radar during the precursory stage of the 2009 eruption of redoubt volcano alaska that provided valuable information during subsequent explosive events we describe the capabilities of this new monitoring tool and present data captured during the redoubt eruption the minimax 250 c mm 250c radar detected seventeen of the nineteen largest explosive events between march 23 and april 4 2009 sixteen of these events reached the stratosphere above 10 km within 2 5 min of explosion onset high column and proximal cloud reflectivity values 50 to 60 dbz were observed from many of these events and were likely due to the formation of mm sized accretionary tephra ice pellets reflectivity data suggest that these pellets formed within the first few minutes of explosion onset rapid sedimentation of the mm sized pellets was observed as a decrease in maximum detection cloud height the volcanic cloud from the april 4 explosive event showed lower reflectivity values due to finer particle sizes related to dome collapse and related pyroclastic flows and lack of significant pellet formation eruption durations determined by the radar were within a factor of two compared to seismic and pressure sensor derived estimates and were not well correlated ash dispersion observed by the radar was primarily in the upper troposphere below 10 km but satellite observations indicate the presence of volcanogenic clouds in the stratosphere this study suggests that radar is a valuable complement to traditional seismic and satellite monitoring of explosive eruptions

tectonic controls on stratigraphic evolution of the adana basin turkey the neogene adana basin of se turkey was initiated after thrust emplacement of the tauride belt to the north of the basin seismic reflection profiles across the southern part of the adana basin provide information on structural and stratigraphic evolution of the basin based on seismic character and the identification of unconformities three megasequences and two mega sequence boundaries are identified the first megasequence is partly coincident with an early miocene rifting event and it comprises reefs that have grown on fault footwall crests with fore and back reef sediments in intervening lows subsequent rapid flexurally induced subsidence generated an underfilled basin which was then passively filled by turbiditic sediments megasequence 2 showing aggradational character on seismic profiles further extensional faulting and coupled sinistral wrench faulting took place after the deposition of megasequence 2 erosional truncation of its upper part is followed by the deposition of continental and shallow marine sediments of megasequence 3 which shows localized progradational sequences characteristic of shallow water deposition further minor extensional faulting took place after the deposition of megasequence 3

kinematic evolution of a large offset continental normal fault system south virgin mountains nevada the south virgin mountains and grand wash trough comprise a mid miocene normal fault system that defines the boundary between the unextended colorado plateau to the east and highly extended crust of the central basin and range province to the west in the upper 3 km of the crust the system developed in subhorizontal cratonic strata in the foreland of the cordilleran fold and thrust system the rugged topography and lack of vegetation of the area afford exceptional three dimensional exposures compact stratigraphy and well defined prefaulting configuration of the rocks permitted a detailed reconstruction of the system reconstruction of cross sections based on more than 300 km2 of detailed mapping at a scale of 1 12 000 shows that the fault system accommodated more than 15 km of roughly east west directed miocene extension extension was initially accommodated on moderately to steeply dipping listric normal faults as the early faults and fault blocks tilted steeply to moderately dipping faults initiated within the fault blocks soling into the early faults some of the early faults were active at dips of 20 isostatically driven tilting is superimposed on tilting due to active slip and domino style rotation of the fault blocks collectively these processes rotated originally steeply dipping faults to horizontal orientations the kinematics are inconsistent with the widely accepted view that many near horizontal normal faults were rotated to their present orientations by later crosscutting normal faults however reexamination of other areas suggests that the evolutionary sequence seen in the south virgin mountains may in fact be widely applicable

infrasonic jet noise from volcanic eruptions 1 the lowermost section of a vulcanian or plinian volcanic eruption column may be thought of as a momentum driven turbulent free shear jet flow we propose that large amplitude and long duration infrasonic 20 hz signals recorded at ranges of tens of kilometers during powerful eruptions at mount st helens usa and tungurahua ecuador represent a low frequency form of jet noise a preliminary test of this hypothesis is made by comparing the observed infrasonic spectra to the empirically derived similarity spectra for pure air jets although the spectral shapes are in approximate agreement the observed volcanic signals have additional complexities not present in the pure air laboratory data these features may result from multiphase flow containing solid particles and liquid droplets very high temperatures and perhaps complex crater morphology however the overall similarity between the volcanic signals and jet noise indicates that broadband infrasound measurements at volcanoes may provide a quantitative link to eruption jet dynamics and would aid substantially in the remote assessment of volcanic hazard

structural and geochemical constraints on the reassembly of disrupted mid miocene volcanoes in the lake mead eldorado valley area of southern nevada in the lake mead eldorado valley lmev area of southern nevada mid tertiary volcanic and plutonic rocks in the river mccullough and eldorado mountains lie in the upper plate of a regional detachment structure the detachment structure and strike slip faults of the lake mead fault zone are temporally and kinematically related strike slip systems and normal faults eldorado valley fault serve as boundaries between regions of variable extension in the upper plate of this detachment geochemical correlation and geometric reconstructions suggest that prior to extension the lmev area was characterized by three stratovolcano complexes each above or adjacent to a chemically correlative pluton geochemical correlation techniques are useful tools that may have general application in reconstructing structurally disrupted volcanic plutonic terranes

characterization of the 2008 kasatochi and okmok eruptions using remote infrasound arrays 1 the 2008 plinian eruptions of kasatochi and okmok volcanoes were recorded by six remote international monitoring system infrasound arrays high amplitude infrasound at these stations combined with remote sensing permits insight into important volcanic source parameters such as origin times durations and source characteristics infrasound from the 7 8 august kasatochi eruption consists of three well defined eruption pulses with the first two steam rich and the last ash rich pulse 2 is the most energetic and impulsive okmok produced over 9 h of continuous infrasound on 12 13 july acoustic propagation modeling for the okmok eruption and first kasatochi pulse predict thermospheric ducting and origin times consistent with seismic and satellite observations however theoretical acoustic origin times of pulses 2 3 are predicted to occur 15 min earlier than the seismic stratospheric ducting for these later pulses provides more consistent origin times although both volcanoes ejected ash into the stratosphere 15 km kasatochi produced higher amplitude infrasound than okmok previous studies have shown sustained infrasound with frequencies 2000 km and does not seem to be appreciably affected by changes in ash content between the eruption pulses

infrasound from tungurahua volcano 2006 2008 strombolian to plinian eruptive activity abstract strombolian to plinian activity from tungurahua volcano ecuador has been recorded by the autonomous infrasound arrays of the acoustic surveillance for hazardous eruptions ashe project since early 2006 our studies suggest that acoustic energy release during large eruptions does appear to broadly scale with eruption intensity this manuscript provides a detailed chronology and characterization of tungurahua s eruptive activity between 2006 and 2008 and demonstrates the ability to constrain source parameters of significant eruptions such as onset duration and escalation at regional distances by combining infrasound and remote sensing techniques the ashe system in ecuador automatically detected over 20 000 volcanic explosions at an array 37 km from tungurahua and was successful at notifying the onset escalation and cessation of a hazardous february 2008 eruption with a latency of 5 min elevated infrasonic energy from sustained and intense tungurahua eruptions correlates well with ash column heights and their lateral extent during the study period the spectra of these sustained explosive eruptions appear to be recurrent readily recognizable and indicative of volcanic jetting and significant atmospheric ash injection the paroxysmal plinian phase of the august 2006 eruption produced an ash cloud that extended well into the stratosphere 24 km coinciding with a shift of the dominant jetting frequency from 0 25 hz to below 0 1 hz and radiation of over 5 107 w of acoustic power transient explosions were often marked by minor or no ash release and are presumed to be more gas rich a change in the acoustic spectrum of volcanic jetting was also detected in the transition from a sustained to collapsed eruption column at the end of the july 14 2006 eruption the jetting spectrum at tungurahua during a period of sustained pyroclastic density current production changes from a typical double peaked to a single peaked spectrum suggesting remote acoustic monitoring can help ascertain the stability and dynamics of an eruptive column

basin genesis associated with strike slip faulting in the basin and range southeastern nevada the structural nature of two prominent basin and range strike slip systems the lake mead fault system and the las vegas valley shear zone are examined using both geological field mapping and geophysical surveys at various scales the intent of this study is to document deformation directly attributable to strike slip faulting with an emphasis on basin genesis our field study of the lake mead fault system reveals a major left step in the system the stepover results in the genesis of a 2 km deep pull apart the overton arm basin consistent with the kinematics and mechanics of strike slip faulting having established the origin of the overton arm basin as a strike slip related pull apart basin the geometry of poorly exposed strike slip systems can be revealed by understanding the related basins along their length one such system the las vegas valley shear zone is shown with the aid of geophysical data to be geographically related to three distinct en echelon basins when these basins are interpreted as pull apart basins the geometry of the las vegas valley shear zone becomes apparent for the first time we assert that strike slip faulting in southeastern nevada is a deformational mechanism that contributes locally to the regional extensional tectonics such an interpretation modifies extant models that treat strike slip faults in rifted terrains as passive lateral boundaries that simply accommodate extension without contributing to the process

hierarchical geocellular facies modelling of a turbidite reservoir analogue from the eocene of the ainsa basin ne spain geocellular models of outcrop analogues can provide useful insights into modelling strategies for the subsurface reservoirs a model of the outcropping ainsa slope turbidite system was built to test the effects of different scales of heterogeneity on production in deep water systems the modelling began with a structural reconstruction based primarily upon the outcrop data to remove the post depositional structural relief of the reservoir analogue the facies modelling workflow consisted of three nested stages each corresponding to a different scale a the first scale addressed the deterministic reconstruction of surfaces that bound sedimentary bodies b the second scale related to the modelling of the interfingering at the gradational boundaries of the sedimentary bodies c the third scale reproduced the internal heterogeneity within the sandstone dominated sedimentary bodies flow simulation was used as a dynamic test of the differences in recovery efficiency for the different scales at which the geological heterogeneity was modelled

changes in the magma system during the 2008 eruption of okmok volcano alaska based on gps measurements 1 the 2008 eruption of okmok volcano was preceded by 6 7 months of immediate precursory inflation which followed 3 years of quiescence during which no significant magma was intruded at shallow depth although gps data for the precursory period are too sparse to derive a unique source model the data show that either the center of pressurization shifted from its 1997 2005 location during the immediate precursory time interval or the shape of the pressure source changed from a sphere to something else deflation during the eruption resulted from a decrease in pressure from a source estimated to be at 2 1 km below sea level using a mogi model although source depth estimates from a mogi model can be biased due to elastic layering or heterogeneity the gps data require the 2008 eruptive source to be shallower than the preeruptive inflation source during the eruption the gps time series indicate three distinct pulses of deflation rather than a single smoothly decaying process with the initial pulse being the largest reinflation of the volcano commenced within at most 3 weeks after the end of ash emissions and was evident at a near source site while a far field site continued to deflate for an additional 4 5 weeks the asynchronous transition from deflation to inflation controlled by the distance of the site from the source indicates that paired deep deflation and shallow inflation is required to explain the observations

subaqueous sediment gravity flow deposits practical criteria for their field description and classification a new method for the description and classification of subaqueous sediment gravity flow deposits is proposed the classification scheme employs a convenient letter code and divides deposits individual beds into descriptive categories of two hierarchical levels facies and subfacies facies as the higher rank categories are distinguished chiefly on the basis of sediment type i e bed grain size texture a total of 13 facies have been distinguished g gravel gs gravel sand couplet gys gravelly sand s sand sm sand mud couplet ms mud sand couplet tm silt mud couplet mt mud silt couplet m mud mys muddy sand sym sandy mud myg muddy gravel gym gravelly mud subfacies as the lower rank categories are distinguished within the individual facies on the basis of the bed s internal structures the number of subfacies is unlimited and their labelling code includes particular facies symbols see above preceded by lower case letters denoting specific sedimentary structures and their vertical arrangement subfacies thus refer to the bed s intervals or divisions which are labelled as follows m massive unstratified and ungraded g graded unstratified and graded s plane stratified x cross stratified 1 parallel and or cross laminated q liquefied for example subfacies gsg graded to plane stratified gravel are gravel beds that have a lower graded interval and an upper plane stratified interval subfacies xg cross stratified gravel are gravel beds that are cross stratified throughout subfacies sls plane stratified to laminated sand are sand beds that have a lower plane stratified interval and an upper laminated parallel and or cross laminated interval

tertiary extension north of the las vegas valley shear zone sheep and desert ranges clark county nevada detailed mapping reveals the presence of high angle extensional faults and low angle gravity slides on the west side of the sheep range three major high angle faulting events each account for 20 of eastward rotation and accommodate extension between the las vegas range and the desert range low angle faults represent surficial slides in response to topography produced by extension on the high angle faults faulting took place during the miocene synchronously with deposition of the horse spring formation and with displacement on the las vegas valley shear zone the extension in the sheep range took place without volcanism intrusion or metamorphism of the paleozoic sedimentary rocks offset thrust faults suggest that the area west of the sheep range extended almost 100 during the miocene while the corresponding area south of the las vegas valley shear zone did not extend significantly the shear zone bounded the extending terrane on the south acting as a transform fault this extension west of the sheep range may in part balance that mapped by anderson 1971 in the eldorado mountains the las vegas valley shear zone and the lake mead fault system may have acted together to compensate for areas of localized extension between the colorado plateau and the vicinity of the specter range

a tectonically controlled alluvial fan which developed into a marine fan delta at a complex triple junction miocene gildirli formation of the adana basin turkey abstract the sediments of the gildirli formation in the karaisali embayment of the adana basin southern turkey records the evolution under tectonic control at a complex triple junction of an alluvial fan into a fan delta during a rapid early miocene transgression the alluvial fan is represented by the lower part of the formation cakmak member and is characterized by an internal architecture recording an overall progradation of the coarse proximal fan conglomerates over distal fine grained sediments the conglomerates contain mostly upper cretaceous limestone clasts of various sizes derived from the faulted mountain front of the taurus range where this limestone is widely exposed this active mountain front delimited the karaisah embayment to the north and provided during the fault activity abundant coarse clasts to this area throughout the deposition of both the alluvial fan and the overlying fan delta sediments the production of fine detritus during the faulting was very limited and therefore this source contributed little fine grain detritus to the sediments provenance studies indicate that the fine clastics in the gildirli formation were carried by streams during periods of active faulting and also during periods of tectonic quiescence from a far distant source in the hinterlands of the taurus mountains the recurrent activity along the northern boundary fault resulted in the intercalation of these fine clastics with the predominant coarse sediments in this formation when the study area was flooded from the south by a rapidly deepening early miocene sea the accumulation of all these sediments took place in a fan delta environment the fan delta sediments constitute the upper parts of the gildirli formation kabalaktepe member and display an inverse facies pattern in which foreset beds overlie topsets and hence an upward fining and deepening sequence this deviation from a genetic upward coarsening sequence of a typical marine delta was perhaps the result of a rapid relative rise in sea level due to tectonically induced subsidence of the area possibly coupled with a short term global sea level rise in the burdigalian