control of relative sea level and climate on coal character in the westphalian c atokan four corners formation central appalachian basin u s a abstract peat successions preserved as coal seams preserve high resolution records of ancient terrestrial water table base level fluctuations that are driven by changes in relative sea level and or paleoclimatic change the aim of this study is to establish the roles of relative sea level and climate in controlling water table fluctuations within coal seams from the fluviodeltaic westphalian c bolsovian atokan four corners formation of the central appalachian basin usa comparison of the characteristics of 10 coals in the four corners formation with accommodation trends identified from analysis of intra coal clastic strata indicates that their thickness and vitrinite inertinite ratio correlate readily with the accommodation setting of the depositional sequence in which they occur coals that accumulated in relatively high accommodation fourth order sequences are high in vitrinite thin and overlain by or intercalated with marine and lacustrine sediments the coals have simple internal organization suggesting that they span parts of single high resolution accommodation cycles coals that accumulated in lower accommodation fourth order sequences are high in inertinite thick and overlain by or intercalated with terrestrial sediments the coals have composite internal organizations typified by multiple high resolution accommodation cycles and characteristic abrupt discontinuities of coal facies representing periods of depositional hiatus the correlations between the composition and thickness of the coals and the magnitude of associated marine transgression imply that relative sea level change was the principal control governing bulk accommodation in these mires landward of the paleoshoreline high frequency accommodation cycles within the coals reflect water table fluctuations in the original mires and were driven by high frequency sea level and or climate change the results of this study provide considerable insight into the manner in which coal composition and stratigraphy at a single locality vary over time in response to changing accommodation and provide a means to predict coal seam quality in an established sequence stratigraphic framework

discriminating stacked distributary channel from palaeovalley fill sand bodies in foreland basin settings abstract stacked fluvial distributary channel deposits and palaeovalley fills can form major multi storey sand bodies with similar thicknesses and with lateral extents often greater than a single exposure consequently they can be difficult to tell apart from one another using outcrop data this study addresses this problem by quantitatively analysing the architecture of five stacked fluvial distributary channel deposits and two palaeovalley fills from the pennsylvanian pikeville and hyden formations of the central appalachian basin usa the a priori interpretation of the sand bodies as stacked distributary channels and palaeovalley fills is possible because a robust in place coal seam correlation framework allows for the recognition of different basin scale architectures for each type aspect ratios 1000 and a regional basinward facies shift at the bases of palaeovalley fills sand body thickness storey thickness position and length of storey contacts within the sand body are similar in both types however they can be distinguished by different up system to down system changes in their respective architectures stacked distributary channel sand bodies thin down system display a decrease in storey thickness an increase in the mean position of storey heights in the sand body and a decrease in the length of storey contacts these trends are the result of down system decrease in channel size and confinement associated with radially distributive fluvial systems palaeovalley fill sand bodies thicken down system display an increase in storey thickness a decrease in the mean position of storey heights and a decrease in the length of storey contacts the increase in sand body and storey thickness are the result of down system increases in original channel size consistent with trunk axial fluvial systems fed by tributaries that predominate during valley formation the down system increase in amalgamation reflects a down system decrease in accommodation from the higher subsidence rate active margin of the basin and is therefore not necessarily characteristic of palaeovalley fill architectures in all basin settings this study emphasises the requirement for detailed correlation work and quantitative analysis of external and internal architectures before the interpretation of sand bodies as stacked distributary channels or palaeovalley fills

multiscale variability of the atmospheric boundary layer during dynamo abstractproperties of the atmospheric boundary layer abl over the central indian ocean are investigated using sounding data obtained during the dynamics of the mjo dynamo field campaign in 2011 12 observations from gan island on addu atoll the r v revelle and male in the maldives are used to determine the frequency of well mixed layers and their mean thermodynamic and wind profiles well mixed boundary layers or mixed layers were observed 68 of the time from the three sites ranging from 100 m depth in recovering convective downdraft wakes to 925 m in undisturbed conditions with a mean depth of 508 m at revelle the site most representative of the open ocean the abl displayed a distinct signal of modulation by the october and november mjos with mixed layer depths gradually increasing through the suppressed phases as the sea surface temperature sst increased leading up to the active phases followed by frequent abl stabilization and shallow mixed layers in recovering wakes a distinct diurn

a composite analysis of the boundary layer accompanying a tropical squall line abstract rawinsonde data from the garp atlantic tropical experiment gate have been used to prepare a composite of the boundary layer associated with a tropical squall line on 12 september 1974 soundings from fifteen gate ships have been composited with respect to the center of the squall radar echo as determined by gamache and houze 1982 for a 9 hour period during which the squall system was approximately in steady state moving to the southwest at 13 5 m s 1 particular emphasis is given to the modified boundary layer or wake that trails the leading edge of the squall system immediately behind the 200 km wide squall line to a distance of 100 km exists a very cool stable layer of air several hundred meters deep just above the ocean surface this region is followed by a shallow mixed layer 100 m deep which gradually increases to 500 m a depth characteristic of undisturbed regions at distances behind the line ranging from 500 km on the northwest side to 300 km on the southeast side surface te

paludal environments of the mary lee coal zone pottsville formation alabama stacked clastic swamps and peat mires abstract the blue creek and mary lee coals in the lower part of the mary lee coal zone upper pottsville formation northwestern alabama record deposition in peat accumulating environments or mires intervening strata contain a series of stacked clastic swamps forested wetlands which grew on a classtic sediment substrate rather than a peat soil these clastic swamp horizons are identified on the basis of 1 autochthonous erect lycophyte and calamites trunks 2 mud cast prostrate hypoautochthonous lycophyte and calamites trunks 3 compression impression assemblages of autochthonous to hypoautochthonous pteridosperm and lycophyte foliage branches and reproductive structures 4 autochthonous axes and appendages of stigmaria and pinnularia and 5 siderite nodules associated with rooting structures and other plant material sedimentological and biostratinomic features of the mary lee coal to blue creek coal interval are used as the basis for the interpretation that sediment loading and compaction of buried peat controlled the alternation between peat mires and clastic swamps and the stacking of the clastic swamps

marine flooding events and coal bed sequence architecture in southern west virginia abstract eight regional lower to middle pennsylvanian coal beds namurian b c to westphalian c in southern west virginia were examined beds were divided into their component sedimentary parts or benches by identifying bounding surfaces and associated siliciclastic partings within beds bounding surfaces represent the cessation of peat accumulation paleo peat mire morphology at the bench level was determined using shape analysis petrographic indices and coal chemistry data planar and raised paleo peat mire benches were identified all gas coal and some splint coal benches were derived from raised mires heterolithic coal and the remaining splint coal benches were derived from planar mires most bounding surfaces are thin composed of oxidized and degraded organic materials high in ash and sulfur content and contain clay minerals and silt sized quartz vitrinite reflectance is suppressed in the upper part of some benches the associated siliciclastic parting materials when thick show evidence of tidal influence and contain brackish water to marine trace fossil assemblages bounding surfaces and the associated sediments represent a sudden increase in water depth and the lateral continuity of these surfaces indicates regional to basinal extent bounding surfaces are the up paleoslope expression of rapid

kinematics of the mw 7 2 12 november 1999 duzce turkey earthquake the november 12 1999 duzce earthquake ruptured a 40 km long fault segment of the north anatolian fault system immediately to the east of the august 17 1999 izmit rupture we use displacements of 32 sites derived from gps measurements immediately before and after the duzce earthquake to estimate the geometry and slip distribution of the coseismic rupture the 51 northward dipping rupture plane the rake of the slip vector average 3 76 0 04 m right lateral 0 76 0 04 m normal slip and the slip distribution inferred from the gps data are consistent with seismic observations and the distribution of surface offsets measured in the field the geodetically determined moment magnitude is mw 7 2 the duzce earthquake had the highest slip to rupture length ratio of any historic earthquake along the north anatolian fault this is consistent with the duzce earthquake being a part of a composite rupture with the preceding izmit event

diurnally modulated cumulus moistening in the preonset stage of the madden julian oscillation during dynamo abstractatmospheric soundings radar and air sea flux measurements collected during dynamics of the madden julian oscillation dynamo are employed to study mjo convective onset i e the transition from shallow to deep convection in the tropical indian ocean the findings indicate that moistening of the low midtroposphere during the preonset stage of the mjo is achieved by simultaneous changes in the convective cloud population and large scale circulation namely cumuliform clouds deepen and grow in areal coverage as the drying by large scale subsidence and horizontal westerly advection wane the reduction of large scale subsidence is tied to the reduction of column radiative cooling during the preonset stage which ultimately links back to the evolving cloud population while net column moistening in the preonset stage is tied to large scale circulation changes a new finding of this study is the high degree to which the locally driven diurnal cycle invigorates convective clouds and cumulus moiste

stratigraphy and depositional environments of the kanawha formation middle pennsylvanian southern west virginia u s a abstract the kanawha formation of southern west virginia consists of up to 620 m of lithic sandstone and mudrocks with subordinate coal and impure limestone that accumulated in a subsiding foreland basin the formation contains 26 of the state s 62 minable coal seams it accounts for about 43 of the coal currently produced in west virginia component sedimentary facies from 46 outcrop localities reflect alluvial paludal lacustrine paralic and shallow marine environments internal and architectural facies attributes indicate more evidence for coastal and tidal estuarine deposition than traditional deltaic models evidence for tidal processes includes bipolar paleocurrents rhythmic textures and structures and associated biogenic structures a new two part model is presented that relates facies to changing coastal morphology during transgressive regressive cycles eustatic sea level changes played a major role in basin wide development of major coal zones and marine units lowstandss of sea level caused incisement of fluvial channels whereas rising sea level led to expansion of tidal plains and estuaries shoreface retreat produced ravinement surfaces and transgressive lags that now separate coastal plain and marginal marine facies from shallow subtidal facies coastal progradation began during highstands after estuarine sediment sinks had filled and may have been intensified during falling sea level

origin of the pennsylvanian coal bearing cyclothems of north america past controversy about the tectonic or eustatic origin of pennsylvanian cyclothems is resolved by regional basin subsidence analysis global paleoclimate paleogeography and plate tectonic evolution differences between marine carbonate kansas type cyclothems of the northern midcontinent and nonmarine clastic appalachian type cyclothems of the eastern united states are controlled by laterally changing flexural deformation during plate accretion into a supercontinent coupled with superposed glacial eustasy kansas type cyclothems accumulated on a relatively stable platform affected only moderately by collision tectonics of north american margins these cycles are eustatic characterized by a periodicity comparable to milankovitch orbital parameters appalachian type cyclothems accumulated in response to episodic thrust loading during plate collisions that developed a series of flexurally deformed wide and shallow resurgent foreland basins this resurgent foreland basin evolution during paleozoic time increased crustal rigidity in the appalachians thus yoking the appalachian and illinois basins during pennsylvanian time with each thrust load foreland basin deepening favored transgressive cyclothem facies which changed to a regressive facies because sediment yield increased as denudation rates increased off uplifted orogens illinois type cyclothems are intermediate between the two end member processes of flexural tectonics and glacial eustasy characterizing appalachian type and kansas type cyclothems respectively thus the pennsylvanian coal bearing cyclothems of north america owe their origin to the remarkable coincidence of supercontinent development concomitant glaciation and eustatic sea level change and associated episodic thrust loading and foreland basin subsidence of small magnitude on progressively more rigid crust

effect of dry large scale vertical motions on initial mjo convective onset anomalies of eastward propagating large scale vertical motion with 30 day variability at addu city maldives move into the indian ocean from the west and are implicated in madden julian oscillation mjo convective onset using ground based radar and large scale forcing data derived from a sounding array typical profiles of environmental heating moisture sink vertical motion moisture advection and eulerian moisture tendency are computed for periods prior to those during which deep convection is prevalent and those during which moderately deep cumulonimbi do not form into deep clouds convection with 3 7 km tops is ubiquitous but present in greater numbers when tropospheric moistening occurs below 600 hpa vertical eddy convergence of moisture in shallow to moderately deep clouds is likely responsible for moistening during a 3 7 day long transition period between suppressed and active mjo conditions although moistening via evaporation of cloud condensate detrained into the environment of such clouds may also be important reduction in large scale subsidence associated with a vertical velocity structure that travels with a dry eastward propagating zonal wavenumbers 1 1 5 structure in zonal wind drives a steepening of the lapse rate below 700 hpa which supports an increase in moderately deep moist convection as the moderately deep cumulonimbi moisten the lower troposphere more deep convection develops which itself moistens the upper troposphere reduction in large scale subsidence associated with the eastward propagating feature reinforces the upper tropospheric moistening helping to then rapidly make the environment conducive to formation of large stratiform precipitation regions whose heating is critical for mjo maintenance

paleoclimate controls on late paleozoic sedimentation and peat formation in the central appalachian basin u s a abstract in the central appalachian basin at least two major climate changes affected sedimentation during the late paleozoic stratigraphically these two changes are indicated by the distribution of coal beds the variation in coal quality and the variation in rock lithologies in latest mississippian or earliest pennsylvanian time the climate changed from dry seasonal tropical to ever wet equable tropical the equable climate prevailed into the middle pennsylvanian influencing the morphology and geochemistry in peat forming environments many of the peat deposits which formed under the equable climate were probably domed raised bogs low concentrations of dissolved solids in peat formation water resulted in low buffering capacity organic acids caused acidic ph another climate change occurred in late middle pennsylvanian time when evapopation periodically exceeded rainfall resulting in an increase of both dissolved solids and ph 4 to 7 in surface and near surface water throughout the remainder of the pennsylvanian the surfaces of peat deposits were probably planar not domed water in peat forming and other depositional environments became more nearly neutral the coal beds derived from these peats are highly variable in both ash and sulfur contents drier or more seasonal climates are also indicated by sequences of 1 calcareous sandstone and shale 2 nonmarine limestone that shows shallow water and subaerial exposure features and 3 calcareous paleosols that have caliche characteristics our data and observations indicate that physical depositional environment models for the origin of coal do not adequately explain variations in mineral matter content and composition in commercial quality coal beds in the central appalachian basin stratigraphic variation in mineral matter in coal beds and in syngenetic and early diagenetic minerals in rocks associated with the coal beds appears to be better explained by changes in geochemical conditions of nonmarine sedimentation paleoclimate was a principle control on these geochemical conditions

aftershock distribution in the eastern part of the aftershock region of the 1999 izmit turkey earthquake a temporary seismic network installed in the eastern part of the aftershock region of the 1999 izmit turkey earthquake revealed that aftershock epicenters were in a very linear alignment near the eastern end of the earthquake fault the linear alignment extended over a length of about 15 km along the segment of the earthquake fault in an ene wsw direction hypocenters on the segment are confined to a narrow depth range near the bottom of the seismogenic region it is inferred from these results that the afterslips occurred in the seismogenic region on the segment before the 1999 duzce earthquake that occurred in the eastern extension of the izmit earthquake fault nearly 3 months after the izmit earthquake it is possible that the afterslips concentrated larger stress on the fault of the 1999 duzce earthquake and generated the earthquake earlier manuscript received 30 august 2000

mesotidal estuarine sequences a perspective from the georgia bight abstract although much has been written about estuaries and estuarine sediments very few facies models have been proposed to date and considerable ambiguity remains in coastal classification schemes current stratigraphic concepts fail to elucidate not only the differences between certain deltaic estuarine and lagoon fill sequences but also the pronounced similarities between many riverine and salt marsh estuarine sequences these distinctive latero vertical successions recent and ancient warrant increased scrutiny and conceptual refinement preliminary stratigraphic models and definitions presented here based largely upon modern georgia estuaries should provide a broad framework for further evaluation and clarification of the above facies relationships from that standpoint an estuarine sequence consists of complex intertidal to subtidal mostly channel form facies dominated to some extent by tidal effects typically displaying abrupt variations in sediment texture and composition and in physical and biogenic sedimentary structures subtle to pronounced salinity gradients may be discernible nevertheless the features most diagnostic of the overall sequence are 1 tidally influenced channel form deposits and 2 characteristic bioturbate textures and trace fossils

simultaneous inversion of waveform and geodetic data for the rupture process of the 1984 naganoken seibu japan earthquake summary a simultaneous inversion method of strong motion seismograms and geodetic data for inferring earthquake rupture process was developed we assumed a source model composed of many point sources of which slip vectors and rupture times are unknown parameters in addition to observed data we introduced smoothing constraints to determine many parameters without instability since the leastsquares solution depends on the relative weights of the smoothing constraints to a data misfit function we determined their values by minimizing akaike s bayesian information criterion abic by using abic we can objectively choose a unique model this inversion method was applied to the naganoken seibu japan earthquake of 1984 dividing a 15 x 10 km fault into 150 subfaults we obtained the minimum abic model with a seismic moment of 2 7 x los dyne cm this model has a slip peak in the eastern and shallow area of the assumed fault the high slip area is just under the areas where thrown out boulders were found by umeda et al 1987 and iio yoshioka 1988 comparing the aftershock distribution with the estimated slip distribution we found that the high slip area had few aftershocks this suggests that aftershocks are caused by the stress generated in the marginal region around the main shock slip the inversion analysis also revealed that there was a slight change in slip angle during the earthquake the high slip area has some amount of dip slip component while the slips in the other areas are almost purely right lateral

convective characteristics of the madden julian oscillation over the central indian ocean observed by shipborne radar during dynamo abstractthis study investigates the convective population and environmental conditions during three mjo events over the central indian ocean in late 2011 using measurements collected from the research vessel r v roger revelle deployed in dynamics of the mjo dynamo radar based rainfall estimates from the revelle c band radar are first placed in the context of larger scale tropical rainfall measuring mission trmm rainfall data to demonstrate that the reduced revelle radar range captured the mjo convective evolution time series analysis and mjo phase based composites of revelle measurements both support the recharge discharge mjo theory time series of echo top heights indicate that convective deepening during the mjo onset occurs over a 12 16 day period composite statistics show evident recharging discharging features in convection and the environment population of shallow isolated convective cells sst cape and the lower tropospheric moisture increase recharge substantially approximately tw

sedimentology of pennsylvanian quartzose sandstones of the lee formation central appalachian basin fluvial interpretation based on lateral profile analysis abstract lateral profiling including bounding surface and architectural element analyses are utilized to demonstrate a fluvial origin for the quartzose sandstones of the lee formation internal architecture of the sandstones consists primarily of multistorey and multilateral channel bodies individual channel elements up to 20 m thick contain a complex hierarchy of bedform deposits the primary depositional elements within the channels were downstream accreting mid channel macroforms channel elements frequently contain deposits of more than one macroform reconstruction of the macroforms reveals accretion primarily by superposed bedforms that migrated down a low angle front steeper giant foresets transitional along flow with the low angle facies indicate that the macroform episodically developed a steep slipface the uppermost channels within the rockcastle member contain macroform elements with components of lateral accretion interpreted as deposits of alternate bank attached macroforms other depositional elements recognized within channel fill deposits are minor channel sandy bedform gravity flow attributed to bank slumping and channel bottom elements the latter element is contained within a facies sequence that suggests rising to flood to waning stage deposition in general deposition probably occurred during relatively high stage little evidence of low stage flow was recognized subordinate fine grained facies are interpreted as levee and overbank deposits the greater part of the lee formation was deposited in deep low sinuosity bedload dominated fluvial channels strongly unimodal paleocurrents lack of facies that suggest low stage reworking and paucity of lateral accretion features indicate deposition in a single channel system i e a low braiding index

regional and economic geology of pennsylvanian age coal beds of west virginia abstract west virginia is the only place in the united states where an entire section of pennsylvanian age upper carboniferous strata can be seen these strata occur within a wedge of rock that thins to the north and west from the southeastern part of the state the progressive north northwesterly termination of older pennsylvanian geologic units beneath younger ones prominently outlines the center of the appalachian basin of west virginia over most of west virginia lower and or middle pennsylvanian strata unconformably overly upper mississippian lower carboniferous strata sediment deposition was accomplished by a complex system of deltas prograding north and west from an eastern and southeastern source area more than 100 named coal beds occur within the lower middle and upper pennsylvanian rocks of west virginia and at least 60 of these have been or are currently being mined commercially collectively these coal beds account for original in ground coal resources of almost 106 1 10 9 t 117 10 9 tons west virginia ranks fourth in the united states in demonstrated coal reserves in 1988 west virginia produced 131 4 10 6 t 144 9 10 6 t of coal third highest in the united states of this annual production 75 was from underground mines in 1988 west virginia led the nation in the number of longwall mining sections currently in place west virginia s low volatile coal beds are known worldwide as important metallurgical grade coals while the higher volatile coal beds are utilized primarily for steam production

three dimensional kinematic and microphysical evolution of florida cumulonimbus part ii frequency distributions of vertical velocity reflectivity and differential reflectivity abstract high resolution radar data collected in florida during the convection and precipitation electrification experiment are used to elucidate the microphysical and kinematic processes occurring during the transition of a multicellular storm from convective to stratiform stages a statistical technique is employed to examine the evolving properties of the ensemble small scale variability of radar reflectivity vertical velocity and differential reflectivity over the entire storm differential radar reflectivity data indicate that the precipitation at upper levels was nearly glaciated early in the storm s lifetime dual doppler radar data show that throughout the storm s lifetime both updrafts and down drafts were present at all altitudes and that most of the volume of the radar echo contained vertical velocities incapable of supporting precipitation size particles thus the ensemble microphysical properties of the storm were increasingly dominated by particles falling in an environment of weak vertic

identifying sources of respirable quartz and silica dust in underground coal mines in southern west virginia western virginia and eastern kentucky prior research has suggested that the source of respirable silica dust in underground coal mines is typically the immediate top or bottom lithology adjacent to the mined seam not mineral matter bound within the mined coal bed geochemical analyses were applied in an effort to identify the specific source rock of respirable quartz dust in coal mines the analyses also demonstrate the compositional changes that take place in the generation of the respirable dust fraction from parent rock material all six mine sites were mining coal with relatively low mineral matter content although two mines were operating in the fire clay coal bed which contains a persistent tonstein interpretations of ca mg mn na and k concentrations strongly suggest that the top strata above the mined seam is the primary source of mineral dust produced during mining one site indicates a mixed or bottom source possibly due to site specific conditions respirable dust compositional analyses suggest a direct relationship between the quantity of mineral si and the quantity of quartz si a similar relationship was not found in either the top or bottom rocks adjacent to the mined seam an apparent loss of elemental al was noted in the respirable dust fraction when compared to potential parent rock sources elemental al is present in top and bottom rock strata within illite kaolinite feldspar and chlorite a possible explanation for loss of al in the respirable dust samples is the removal of clays and possibly chlorite minerals it is expected that removal of this portion of the al bearing mineral matter occurs during rock abrasion and dust transport prior to dust capture on the samplers

coal mining along the warfield fault mingo county west virginia a tale of ups and downs abstract mine development along a 15 mile 24 km section of the warfield fault in mingo county west virginia has broadened the geological understanding of the fault and its related structures the fault has been exposed in two new road cuts one in the northeast trending segment at neely branch and one in the eastern east trending segment at the head of marrowbone creek both exposures show a well defined normal fault with a 45 to 55 n dip juxtaposing sandstone shale packages from the roof and the floor of the coalburg seam the fault is associated with a thin gouge zone some drag folding and parallel jointing its trace tends to run parallel to the crest of the adjacent warfield anticline based on underground mine development and detailed core drilling the vertical offset along the fault plane ranges from a maximum of 240 ft 73 m in the central part of the area near the structural bend to less than 100 ft 30 m in western and eastern directions the fault is located along the relatively steeply dipping locally in excess of 25 southern limb of the warfield anticline and appears related to a late phase of extension involving folded pennsylvanian strata on a regional scale the lithological variations across the fault do not suggest any appreciable strike slip component underground room and pillar mines in the coalburg seam north and south of the fault have been greatly impacted by the warfield structures due to the combined and opposite effects of the folding and faulting the northern mines are located up to 400 ft 125 m higher in elevation than the southern ones overland conveyor belts connect mining blocks separated by the fault the practical mining limit along the steep slopes toward the fault is around 15 subsidiary normal faults with offsets in the 5 to 15 ft 1 5 4 5 m range are fairly common and form major roof control and production hurdles overall the warfield structures pose an extra challenge to mine development in this part of the appalachian coalfields

vertical structure of the tropical boundary layer abstract obsemations presented show that the undisturbed subcloud layer near the itcz resembles that of the trades mixed and transition layers are also seen between cloud drafts during disturbed periods when shallow mixed layers 200 m can persist for several hours modification of the lower atmosphere during disturbed periods is most marked in the lowest 1200 m mixed layers are observed during prolonged disturbed periods disturbed mixed layers are shallower and cooler than undisturbed ones light and moderate rainfall events moisten the mixed layer but mixed layers in the environment around strong rainfall are drier it is hypothesized that that the effect of a number of downdrafts spreading laterally produces the mixed layer cooling and drying observed changes of mixed layer structure with stability measured by the ratio of mixed layer height to the monin obukhov length are presented

observation of quasi 2 day convective disturbances in the equatorial indian ocean during dynamo abstractthis study examines the westward propagating convective disturbances with quasi 2 day intervals of occurrence identified over gan island in the central indian ocean from mid to late octobe

diurnal cycle of the itcz in dynamo abstractduring the 2011 special observing period of the dynamics of the madden julian oscillation dynamo field experiment two sounding arrays were established over the central indian ocean one

surface rupture and slip distribution of the 12 november 1999 duzce earthquake m 7 1 north anatolian fault bolu turkey the 12 november 1999 earthquake m 7 1 occurred on the duzce fault a splay of the north anatolian fault in the bolu basin approximately three months after the 17 august 1999 m 7 4 earthquake the surface rupture was 40 km long and the maximum right lateral offset was 500 5 cm averaging 300 cm the 9 km of the westernmost part of the rupture along the southern margin of the eften lake had a 350 cm maximum vertical displacement normal faulting some of which was already ruptured during the 17 august 1999 event with few tens of centimeters the surface rupture has a generally simple narrow deformation zone of 0 5 5 m however in some places it widens to 50 m transtensional and transpressional structures were observed within releasing and restraining step over areas respectively the larger dextral offsets on some streams indicate previous events the dextral slip measurements along the rupture reflect a symmetric distribution the eastern connection of this rupture zone with the main trace of north anatolian fault remains unclear because the bakacak and elmalik fault which are connecting faults had no surface rupture manuscript received 14 november 2000

pennsylvanian deposystems and paleoclimates of the appalachians abstract central appalachian basin rocks indicate major changes in source areas base level and climate for late mississipian through late pennsylvanian time through time dominant source areas change from craton and northeastern orogen to southeastern orogenic mountains the mississipian pennsylvanian uncomformity correlates with a worldwide eustatic event early pennsylvanian rocks contrast markedly with underlying mississippian mauch chunk redbeds in composition and texture yet the source areas and alluvial plain setting were similar seas transgressed northeastward during middle and earliest late pennsylvanian time along axes of the pocahontas and dunkard basins while fluvial dominant deltas prograded northwestward this progradation 1 progressively extended the coastal plain 2 provided coastal swamp environments for peat accumulation and 3 eventually cut off the narrow seaway of dunkard basin from the central interior by late pennsylvanian and transformed it into a large shallow freshwater lake redbeds calcium carbonate concretions and gilgai paleosol structures of late mississippian and late pennsylvanian rocks suggest seasonally dry tropical climate whereas the lithologies of the earlier pennsylvanian rocks are indications of everwet tropical climates with their quartz rich fluvial sandstones high quality coals and aluminum rich clay deposits streams change from predominantly bedload to suspended load generally from early to late pennsylvanian in response to changes in paleoslope gradient distance from source area unvegetated highland and change from everwet to intermittently dry tropical climate greater dryness is suggested for increased alkaline conditions observed in paleosols carbonates and coal beds of late pennsylvanian time but sufficiently wet to prevent evaporite deposition

correlation of carboniferous strata using a hierarchy of transgressive regressive units carboniferous strata can be described interpreted and correlated using six scales of allocyclic transgressive regressive t r units these t r units are inferred to be the net result of deposition during cycles of sea level change all pennsylvanian and lower permian strata constitute one second order t r unit or synthem the pennsylvanian system contains third fourth fifth and sixth order t r units that can be correlated across both marine and nonmarine facies in the appalachian basin this permits differentiation of allocyclic t r units from autocyclic t r units or fluvial autocyclic units the hierarchical approach is also useful for predicting the location of marine horizons coals claystones and various types of stratigraphic breaks a hierarchical scheme of allocyclic t r units could be combined with biostratigraphic radiometric and magnetostratigraphic data to form a practical chronostratigraphic framework for the carboniferous

evolution of precipitation and convective echo top heights observed by trmm radar over the indian ocean during dynamo radar data from the tropical rainfall measuring mission show the evolution of echo tops of convective elements over the indian ocean and maritime continent during the dynamics of the madden julian oscillation dynamo field campaign of 2011 2012 echo top heights exhibited a bimodal distribution wherein cumulonimbi of moderate height constituted a congestus mode while vertically extensive cumulonimbus made up a deep mode an intraseasonal time scale dominated variability in these modes from october to january over much of the indian ocean over the maritime continent there was no clear intraseasonal signal in convective echo top heights where the intraseasonal oscillation was detected radar echoes evolved from being dominated by the congestus mode to being characterized by more deep mode convection on time scales of less than 1 week the areal coverage of congestus echoes began to increase 2 8 days prior to the rise in area of deep echoes these satellite derived results confirm that the time scale for convective deepening seen at individual dynamo observational sites is consistent with that of convection on the large scale over the indian ocean intraseasonal variability of zonal wind temperature and humidity as depicted by reanalysis is also consistent with that derived from rawinsonde observations during dynamo thus the gradual buildup of convection as depicted by recent versions of the discharge recharge hypothesis does not accurately describe evolutions of convection prior to mjo events observed during dynamo although cloud moistening processes may still be relevant on time scales of 1 week or less

model for transgressive black shales many black shales in thick epicontinental basinal successions formed beneath an oxygen restricted puddle of deep water other black shales formed during rapid transgression when basinal deposition expanded to cover basin margin areas normally characterized by shallow water deposition an expanding puddle model is developed from the early jurassic of england wherein rapid sea level rise leads to marine sediment starvation due to sediment entrapment in flooded river valleys subsidence sea level rise and decreased sediment supply during early transgression are suggested to lead to rapid deepening and therefore the expansion of the are of the puddle such that in previously shallow water areas black shales rest on condensed basal transgressive lags or unconformities that in turn rest on shallow water facies reestablishment of sediment influx and aggradation in excess of any continued sea level rise cause shallowing throughout the basin and the cessation of black shale formation

rupture processes of the 1999 august 17 izmit and november 12 duzce turkey earthquakes summary we derive the rupture history of the 1999 august 17 izmit mw 7 4 and 1999 november 12 duzce mw 7 1 earthquakes in turkey from teleseismic body waves using broad band data of the global seismograph network aftershock locations and mapped surface breaks the centroid solutions indicate strike slip mechanisms for both events the izmit earthquake was characterized by rupture propagating predominantly eastwards it consisted of a main rupture lasting about 25 s followed within 1 min by two more events of mw 6 9 and mw 7 0 with the teleseismic data we could not resolve the westward extent of rupture into the marmara sea however an upper bound of the seismic moment release west of the epicentre of the izmit event is estimated to be 1 9 1019 n m the duzce earthquake lasted about 14 s and was characterized by a bilateral mode of rupture in excellent agreement with mapped surface breaks and aftershock locations

structure and evolution of the 22 february 1993 toga coare squall line aircraft observations of precipitation circulation and surface energy fluxes abstract this study documents the precipitation and kinematic structure of a mature eastward propagating oceanic squall line system observed by instrumented aircraft during the tropical ocean global atmosphere coupled ocean atmosphere response experiment toga coare doppler radar and low level in situ observations are used to show the evolution of the convection from an initially linear nnw sse oriented convective line to a highly bow shaped structure with an embedded low to midlevel counterclockwise rotating vortex on its northern flank in addition to previously documented features of squall lines such as highly upshear tilted convection on its leading edge a channel of strong front to rear flow that ascended with height over a rear inflow that descended toward the convective line and a pronounced low level cold pool apparently fed from convective and mesoscale downdrafts from the convective line rearward the observations of this system showed distinct multiple maxima in updraft strength with

the application of high resolution sequence stratigraphy to fluvial systems a case study from the upper carboniferous breathitt group eastern kentucky usa the pennsylvanian pikeville hyden and four corners formations of the breathitt group in eastern kentucky usa contain six major facies associations along with a number of subassociations these facies associations are offshore siltstone rhythmically bedded mouthbar heteroliths predominantly fine grained floodplain deposits minor channel fills major distributary channels and major stacked fluvial bodies the stacked fluvial bodies are incised into a variety of open marine and delta plain deposits have widths of several kilometres and exhibit a range of sandy fill types these fluvial complexes are interpreted as incised valley fills parasequences and parasequence sets are not identifiable nonetheless it is possible to identify systems tracts on the basis of sequential position facies associations and systematic changes in architectural style and sediment body geometries the studied portion of the breathitt group comprises stacked 4th order sequences which occur in lowstand transgressive and highstand sequence sets related to the development of a lower frequency base level cycle in the lowstand sequence set incision associated with successive 4th order sequence boundaries has commonly removed all the hst and tst of the underlying sequences such that succeeding 4th order incised valley fills are amalgamated within the transgressive sequence set incision is at a minimum and incised valley fills tend to stack discretely with the maximum amount of fine grained tst and hst between them the highstand sequence set is transitional between the lowstand and transgressive sequence sets in terms of the amount of transgressive and highstand deposits preserved incised valley fills tend to stack discretely

re os age for the lower middle pennsylvanian boundary and comparison with associated palynoflora abstract the betsie shale member is a relatively thick and continuous unit that serves as a marker bed across the central appalachian basin in part because it includes an organic rich shale unit at its base that is observable in drill logs deposited during a marine transgression the betsie shale member has been correlated to units in both wales and germany and has been proposed to mark the boundary between the lower and middle pennsylvanian series within north america this investigation assigns a new re os date to the base of the betsie and examines the palynoflora and maceral composition of the underlying matewan coal bed in the context of that date the matewan coal bed contains abundant lycopsid tree spores along its base with assemblage diversity and inertinite content increasing upsection as sulfur content and ash yield decrease taken together these palynologic and organic petrographic results suggest a submerged paleomire that transitioned to an exposed peat surface notably separating the lower and upper benches of the matewan is a parting with very high sulfur content 28 wt perhaps representing an early marine pulse prior to the full on transgression responsible for depositing the betsie results from re os geochronology date the base of the betsie at 323 7 8 ma consistent with previously determined age constraints as well as the palynoflora assemblage presented herein the betsie shale member is also highly enriched in re ranging from 319 7 to 1213 ng g with high 187 re 188 os values ranging from 3644 to 5737 likely resultant from varying redox conditions between the pore water and overlying water column during deposition and early condensing of the section

sequence stratigraphic interpretation of a pennsylvanian upper carboniferous coal from the central appalachian basin usa peat mires retain a sensitive record of water table base level fluctuations throughout their accumulation on this basis coals provide one of the best opportunities to interpret high resolution base level change in ancient non marine deposits the petrographic composition of 275 samples collected from 11 localities along a 100 km south west to north east transect across the regionally extensive 37 000 km2 pennsylvanian upper carboniferous fire clay coal of the central appalachian basin usa was analysed to determine its internal stratigraphy the coal is positioned within the late lowstand early transgressive systems tract of a fourth order depositional sequence the results of the petrographic analyses reveal a cyclicity in the composition of the fire clay coal which defines six units that are correlated over more than 100 km each coal cycle is characterized by a gradual upward transition from vitrinite dominated to inertinite dominated coal which represents a drying up succession increased concentrations of resistant peat components at the top of the drying up successions indicate reduced peat accumulation rates associated with slowing rate of water table rise and may represent a residue of peat remaining from a phase of exposure and erosion resulting from a falling water table these drying up successions are bound by surfaces that display an abrupt coal facies shift from inertinite rich to vitrinite rich coal representing a rapid water table rise each cycle represents markedly different mire conditions with different aerial distributions which supports the notion of temporal disconnection between each unit of coal and suggests that considerable time may be locked up in unit bounding exposure surfaces recognition that the rate of peat accumulation in a mire may vary considerably through time has important implications for studies which assume that peat and coal successions provide continuous and time invariant records of base level fluctuations or palaeoecological change

coal more than a resource critical data for understanding a variety of earth science concepts abstract coal is one of the world s primary energy sources and it is critical for making coke used in steel making and is used for a multitude of chemical products aside from its significance as a fuel or product however coal and data derived from the exploration or mining of coal have also provided the foundation and testing ground for diverse geologic concepts because of coal s economic importance and common variability in thickness distribution and quality it has been critical to collect and correlate a wide variety of surface and subsurface data sets at relatively high spatial frequency which varies from the mine to basinal scale also because many coal beds occur in most coal basins the collection of coal data from multiple beds creates relatively high temporal frequency data sets at scales from laminae to bed to larger unit scale these data have been important for the development and expansion of many earth science concepts including aspects of basin analyses paleogeography paleoclimatology paleontology stratigraphy sedimentology structural geology and tectonics

source rupture process of the kocaeli turkey earthquake of august 17 1999 obtained by joint inversion of near field data and teleseismic data the rupture process of the 1999 turkey earthquake is examined using both near field strong motion data and teleseismic body wave data the derived source parameters are as follows strike dip slip 268 86 180 nearly pure strike slip the seismic moment mo 1 7 1020 nm mw 7 4 the source duration 20 sec the fault length 70 km the fault width 15 km the rupture process is characterized by an asymmetric bilateral rupture propagation and smooth slip it consists of two major fault segments a rupture propagating to the west and a second rupture propagating to the east the maximum dislocation and the maximum dislocation velocity are 6 3 m and 2 7 m s respectively both found at the former segment the average dislocation is about 4 m the extent of the coseismic rupture suggests that a considerable part of the anticipated seismic gap remains unruptured

an appalachian sourced deltaic sequence northeastern alabama usa biofacies lithofacies relationships and interpreted community patterns abstract the thin sequence of lower pennsylvania rocks along sand mountain plateau coal field northeastern alabama u s a records the deposition in a deltaic coastal plain paleoenvironment along the ancient appalachian seaway the section is laterally continuous well exposed and preserves a rich macrobiota identified coexisting paleodepositional environments contain distinctive biofacies specific paleoenvironments of deposition contain unique biofacies in this late carboniferous westphalian a sequence the criteria established for the recognition of these biofacies can be utilized to assist in refined interpretations of deltaic sites in carboniferous coastal paleoenvironments identifiable biofacies include those preserved under a variety of forested wetland swamp conditions distributary and crevasse splay channels coastal bays interdistributary and lagoonal barrier sands and distal storm deposits fig 1 gastaldo et al 1989 vegetation in forested wetlands grew either in clastic substrates or peat substrates the principal biofacies preserved in clastic substrate swamps were lycophyte dominated and can be recognized by either a predominance of canopy litter or subterranean stigmarian appendages gastaldo 1986 the canopy litter that has accumulated on the forest floor was preserved under unique sedimentological conditions and reflects the ecological gradient associated with the distribution of lycophyte genera in the swamp gastaldo 1987 a monotypic assemblage of lycophytes characterized edaphically stressed sites in sites proximal to the levee a mixed assemblage of lycophytes calamiteans pteridophytes and pteridosperms is common in the absence of compressed canopy macrodetritus subterranean axes with helically arranged appendages rootlets crosscutting the bedding may be preserved macro invertebrates are restricted to traces and trails reflecting behavioral traits when conditions were conducive for their movement into these sites peat colonizing vegetation parallels that of the clastic swamp deep distributary channels contain sandstone cast and compressed aerial trunks of lycophytes and spenophytes these occur in bedload deposits along with quartz and quartzose pebbles and cobble size phyllite clasts degradation of external morphology usually precludes assignment of logs to a systematic position lower than order in shallower en echelon stacked crevasse sands occur a mixture of lycophyte calamitean and pteridosperm woody parts additionally scoriaceous fern like foliage may be found little evidence exists for macro invertebrate communities in these unstable settings coastal bays preserve in situ macro invertebrate communities as well as allochthonous macrodetritus that was derived principally from levee vegetation four phases of biofacies development can be delineated gibson and gastaldo 1987 stress tolerant inarticulate brachiopods dominate the initial transgressive phase individuals are found isolated in the siltstone commonly preserved by authigenic cementation in siderite concretions rarely are patches or clusters of individual encountered where clustering does occur it is associated with the colonization of woody plant parts transition to the molluscan dominated phase is accompanied by the establishment of a rich ichnofauna continued transgression and the development of more normal salinities under lagoonal conditions are paralleled by an increase in species richness and abundance the third biofacies phase remains molluscan dominated but the assemblages at any particular point in time are represented by monospecific genera plant macrodetritus was utilized by the macro invertebrate communities and that which is preserved is restricted to highly fragmentary unindentifiable remains the fourth biofacies phase reflects the development of lagoonal conditions this change can be recognized by macro invertebrate body and ichnofossil fauna seilacher s cruziana ichnofacies diversification an increase in the abundance of brachiopods and other invertebrates is considered to represent more open marine conditions barrier sandstone and distal storm deposits contain disarticulated epifaunal brachiopods bivalves gastropods and trilobites these stenohaline forms are concentrated in a shell lag at the base of migrating barrier sand bodies the overlying sandstone is devoid of macro invertebrate body fossils and plant macrodetritus but is characterized by the colonization of zoophycos traces

transgressive channel filling in the breathitt formation upper carboniferous eastern kentucky coal field usa abstract carbonaceous shales of brackish or marine origin in the breathitt formation may exhibit sharp bases with local channel form scours minor channels at the bases of these shales exhibit three general types of fill 1 shale 2 bioturbated heterolithic strata and 3 coal overlain by shale or bioturbated heterolithic strata most of the scours at the bases of the channels were formed during a depositional hiatus that preceded transgression some may also have been formed by transgressive reworking of underlying estuarine and deltaic siliciclastics the channel fills are bioturbated and may contain crudely cyclical rhythmites subordinate and dominant siltstone laminae couplets wave ripples and bimodal current ripple trends the fills are interpreted to represent estuarine sedimentation during marine transgression channels are capped by sideritic bioturbated sandstones that separate the fills from the overlying dark shales deposited under brackish to marine water conditions some of these sandstones may represent local transgressive surfaces the occurrence of these types of channels in different parts of the coal bearing breathitt formation supports the hypothesis of multiple transgressions during the late carboniferous in the central appalachian basin

idealized modeling of the atmospheric boundary layer response to sst forcing in the western indian ocean abstractthe atmospheric response to sea surface temperature sst variations forced by oceanic downwelling equatorial rossby waves is investigated using an idealized convection resolving model dow

paleoclimate controls on stratigraphic repetition of chemical and siliciclastic rocks climate is a primary control on sediment flux from continental sources into sedimentary systems in warm climates siliciclastic input is greatest under highly seasonal rainfall nonseasonal conditions favor formation of end member chemical rocks perennially wet climates are conducive to coal formation whereas dry climates produce carbonates and or evaporites stratigraphic repetition of siliciclastic and chemical rocks therefore appears to be related to paleoclimate cycles as well as to transgressive regressive events and tectonics

a methodology for seismic loss estimation in urban regions based on ground motion simulations seismic vulnerability assessment of residential buildings in regions of high seismicity is an interdisciplinary problem requiring major inputs from fields of seismology and earthquake engineering the basic two components of loss estimation methods are information on regional seismicity and building stock this study presents a realistic loss estimation methodology where the first component input ground motions is obtained from regional ground motion simulations using the stochastic finite fault technique the second component building vulnerability information on the other hand is taken into account using fragility analyses introducing the ground motion intensity parameters obtained from simulations to the fragility curves we obtain seismic loss distribution in a region in this study we demonstrate the loss estimation methodology with an application to three northwestern cities in turkey duzce bolu and kaynasli that experienced two major earthquakes graphic 1 and graphic 2 in less than three months in 1999 we initially verify the methodology with comparisons of observed and estimated damage ratios for the 12 november 1999 graphic 3 duzce earthquake later we present the estimated damage ratios under scenario earthquakes in the region for a magnitude range of graphic 4 graphic 5 is predicted to be the threshold magnitude for the cities of duzce and kaynasli where more than 60 of the building stock experience moderate and heavy damage because bolu is at a farther distance from the fault plane less damage is estimated for graphic 6 than those in the other centers for graphic 7 all three cities are predicted to experience substantial rates of heavy damage and collapse 1 embed inline graphic 1 gif 2 embed inline graphic 2 gif 3 embed inline graphic 3 gif 4 embed inline graphic 4 gif 5 embed inline graphic 5 gif 6 embed inline graphic 6 gif 7 embed inline graphic 7 gif

the rupture process during the 1999 duzce turkey earthquake from joint inversion of teleseismic and strong motion data abstract teleseismic and strong motion data are inverted to determine the rupture process during the november 1999 duzce earthquake in nw turkey the fault geometry rise time and rupture velocity are determined from the aftershock distribution and preliminary inversions of the teleseismic data joint inversion of the teleseismic and strong motion data is then carried out for the slip distribution we obtain the strike 264 dip 64 rake 172 seismic moment 5 0 1019 n m mw 7 1 and average stress drop 7 mpa this earthquake was characterized by bilateral fault rupture and asymmetric slip distribution two asperities areas of large slip are identified the eastern one being 1 5 times larger than the western one the derived slip distribution is consistent with the aftershock distribution surface rupture and damage the point of rupture initiation in this duzce earthquake coincided with the eastern tip of the aftershock distribution of the august 1999 izmit earthquake

evolution of some depositional models in late carboniferous rocks of the appalachian coal fields abstract models for carboniferous coal bearing strata developed early in this century and consisted of vertical columns that described commonly occurring sequences of coal beds and associated rocks these were followed by other models that expressed patterns of both vertical and lateral variation but in those as well as earlier models depositional interpretation did not extend much beyond a basic marine nonmarine dichotomy subsequently depositional processes were linked to lithic components and showed that the areal distribution of these components formed a lateral geomorphically controlled continuum ranging from alluvial plains seaward to barrier islands evaluation of this model within a tectonic setting of rapid and differential subsidence produced by growth faulting in the southern part of the appalachian coal fields has shown that while depositional processes are substantially the same as those suggested by the model the form and spatial distribution of resulting lithic components are profoundly affected by movements on contemporaneously active subsurface structures this leads to the conclusion that previous models are a product of depositional processes strongly controlled by their tectonic setting and that further attempts at model generation will require careful assessment of the relationships of lithic distribution to subsurface structures and amounts of data necessary to recognize them

heightened odds of large earthquakes near istanbul an interaction based probability calculation we calculate the probability of strong shaking in istanbul an urban center of 10 million people from the description of earthquakes on the north anatolian fault system in the marmara sea during the past 500 years and test the resulting catalog against the frequency of damage in istanbul during the preceding millennium departing from current practice we include the time dependent effect of stress transferred by the 1999 moment magnitude m 7 4 izmit earthquake to faults nearer to istanbul we find a 62 15 probability one standard deviation of strong shaking during the next 30 years and 32 12 during the next decade

implications on the paleoecology of autochthonous lycopods in clastic sedimentary environments of the early pennsylvanian of alabama abstract numerous correlative localities throughout the upper cliff coal interval lower pennsylvanian blount county alabama have been observed in which lycopod forests are preserved these assemblages are present in lower delta plain facies interpreted to represent 1 the abandonment phase of a distributary channel system with resultant bayou development 2 non peat accumulating swamps capping interdistributary bay deposition 3 possible terminal phase of peat accumulating swamps and 4 crevasse splay deposits field observations in combination with sedimentological preservational and biological evidence support the conclusion that these autochthonous carboniferous lycopods represent a taphonomically biased assemblage of aquatic or semi aquatic swamp communities interpretations derived from the present study in conjunction with published accounts of erect lycopods suggest that these plants could tolerate all waters from fresh to saline conditions periodic drying of swampy habitats may have subjected lycopods to subaerial and aerial conditions but bulk replaced erect lycopods predominantly inhabited water stressed conditions the monotypic character of the lycopod forests supports the hypothesis that in the tropical lowlands of the tropical lowlands of the carboniferous lycopods held a relatively unique physiologically stressed position in the delta flood basin these arborescent lycopods became established in any depositional site subject to flooding and standing water when conditions prevailed which allowed for the establishment and development of individuals

depositional response to foreland deformation in the carboniferous of eastern kentucky the appalachian basin is a typical foreland basin that has subsided episodically under the loads of successive thrust sheets the dynamics of basin subsidence and upwarping of basin margin arch systems reflects the flexural properties of the lithosphere quantitative models of the lithosphere depend on assumed rheological properties this study attempts to test these geodynamic models in a part of the appalachian basin mississippian deposition is correlated with waning acadian tectonism orogenic quiescence coincided with basin overdeepening and uplift of the cincinnati arch or forebulge although the foreland basin was mudstone dominated shoaling along the crest of the basin margin arch system resulted in reworking and wedges of unconformities in contrast the onset of alleghenian orogenesis during the pennsylvanian is reflected in a thick wedge of terrigenous clastic sediments the pennsylvanian basin fluctuated between underfilled restricted marine and overfilled nonmarine conditions rapid response of the basin to thrust sheet loading is inferred these characteristics of mississippian and pennsylvanian deposition support a viscoelastic model of the lithosphere