recovering seismic displacements through combined use of 1 hz gps and strong motion accelerometers retrieving displacement from seismic acceleration records is often difficult because unknown small baseline offsets in the acceleration time series will contaminate the doubly integrated record with large quadratic errors one hertz global positioning system gps position estimates and collocated seismic data are available from the 2003 m w 8 tokachi oki hokkaido earthquake after a process of correcting for possible misorientation of the seismic sensors an inversion method is used to simultaneously solve for ground displacement with both data sets as input constraints this inversion method takes into account the presence of unknown offsets in the acceleration record and the relatively large uncertainties in the estimated 1 hz gps positions in this study 117 channels of seismic data were analyzed only 5 of the time does the static displacement retrieved from traditional baseline correction processing without gps information agree with the absolute displacement measured with 1 hz gps to within the errors of the gps data in solving simultaneously for constrained displacements that agree with both the seismic and gps data sets an optimal solution was found that included only one or two step functions in the acceleration records potential explanations for the offsets are analyzed in terms of tilt of the sensor or electronic noise for nine stations clear misorientations of the seismic sensors of more than 20 deg from the reported orientation were found for this size event the 30 sec sampled gps solutions were also a sufficient constraint for establishing the offset errors and recovering reliable displacements the results significantly extend the frequency band over which accelerometer data are reliable for source inversion studies online material plots of constrained seismograms with metadata

love wave dispersion in central north america determined using absolute displacement seismograms from high rate gps 1 we use seismic array processing of high rate gps hrgps displacement time series from the great 2004 mw 9 sumatra andaman earthquake recorded at over 90 nonuniformly distributed hrgps stations in central north america to determine the fundamental love wave phase velocity dispersion curve there these measurements were performed using frequency domain beam forming which we show reduces the effects of gps multipath and common mode noise on the measurement of surface wave phase velocity and azimuth our hrgps based results for surface wave phase velocity agree well with those obtained from 28 broadband seismometers between periods of 20 to 300 s by separating waves based on their apparent velocity beam forming supports the simple model for relative displacement hrgps time series as being the difference between the reference and kinematic station s absolute displacements beam forming also demonstrates that for differential gps processing the infinite apparent velocity beam of an array is composed of the sum of common mode noise and the reference station s absolute displacements multipath and noise we show the infinite apparent velocity beam which we call the generalized spatial filter is similar to the spatial filter commonly used to remove common mode noise from hrgps seismograms and can be used to produce absolute displacement time series for the kinematic stations with reduced common mode noise beam forming also suggests a filtering method complimentary to sidereal filtering to produce gps multipath reduced hrgps time series

classification of huminite iccp system 1994 abstract in the new classification iccp system 1994 the maceral group huminite has been revised from the previous classification iccp 1971 int handbook coal petr suppl to 2nd ed to accommodate the nomenclature to changes in the other maceral groups especially the changes in the vitrinite classification iccp 1998 the new vitrinite classification iccp system 1994 fuel 77 349 358 the vitrinite and huminite systems have been correlated so that down to the level of sub maceral groups the two systems can be used in parallel at the level of macerals and for finer classifications the analyst now has according to the nature of the coal and the purpose of the analysis a choice of using either of the two classification systems for huminite and vitrinite this is in accordance with the new iso coal classification that covers low rank coals as well and allows for the simultaneous use of the huminite and vitrinite nomenclature for low rank coals

petrological and geochemical composition of lignite from the d field kolubara basin serbia abstract the upper miocene lignite from the main coal seam in the d field kolubara basin is a typical humic coal with huminite liptinite and inertinite concentrations of up to 83 7 vol 17 2 vol and 15 5 vol respectively in the huminite group textinite and ulminite are the most abundant macerals with variable amounts of densinite and attrinite liptodetrinite and sporinite are the most common macerals of the liptinite group while inertodetrinite is the most abundant maceral of the inertinite group the mineral matter consists mostly of clay minerals the main sources of organic matter were gymnosperms conifers and microbial biomass followed by angiosperms based on composition of saturated and aromatic diterpenoids it has been established that coal forming plants belonged to the gymnosperm families taxodiaceae podocarpaceae cupressaceae araucariaceae phyllocladaceae and pinaceae peatification occurred in neutral to slightly acidic fresh water environment composition and distribution of biomarkers show that diagenetic changes of the organic matter were mainly governed by bacterial activity in a suboxic to oxic environment based on distribution of aromatic diterpenoids a novel diagenetic pathway for transformation of abietane type precursors under suboxic to oxic conditions is proposed variations in compositions of macerals and biomarkers are in concordance with pronounced seasonality during pontian which caused changes in the water level redox conditions during peatification and to some extent vegetation differences in the paleo plant communities

revisiting coos bay oregon a re examination of funginite huminite relationships in eocene subbituminous coals coal petrography has advanced significantly since reinhardt theissen and james schopf pioneered the use of thin sections to examine coals from coos bay oregon and to many coal petrographers the nomenclature used in that study is irrelevant the schopf 1947 study was a ground breaking examination of maceral relationships that need to be part of the working vocabulary of modern petrographers to support this a re examination of the coos bay thin section collection was undertaken using modern nomenclature for low rank coals under reflected light this particular collection was chosen in part because of the abundance of fungal material reported by schopf fungal material in coal and its association with huminite vitrinite macerals provides important information about the decompositional history of the coal and allows coal dominated by oxic processes to be differentiated from coal dominated by anoxic processes in the coos bay samples predominantly oxic intervals contain well preserved fungi including spores sclerotia and hyphae while anoxic intervals contain no fungi

liptinite in coal and oil source rocks in northern thailand abstract palynological study of northern thailand coal and oil deposits indicates a similar palynological association to that of the borneo region coal petrographic studies of these deposits show variations in the liptinite macerals especially alginite types the oldest of these coal and oil deposits which are of late oligocene to early miocene age are dominated by botryococcus sp or botryococcus related algae thick walled lamaginites and spores and pollen of temperate affinity are found in some areas by contrast thin walled lamaginite is dominant in late middle miocene time resinite suberinite and cutinite are dominant in forest swamp coal deposits whereas alginite cutinite and lycopodium spores are dominant in lacustrine environments exsudatinite is common even at early levels of maturation these liptinite macerals can be major sources of oil and gas

very high rate 10 hz gps seismology for moderate magnitude earthquakes the case of themw6 3 l aquila central italy event accepted for publication in journal of geophysical research copyright 2010 american geophysical union

observations and experiments on the origin and formation of inertinite group macerals the inertinite group macerals include fusinite semifusinite inertodetrinite macrinite micrinite and funginite and secretinite which together replace sclerotinite the macrolithotype fusain comprises fusinite and semifusinite and is now widely accepted as charcoal formed by wildfire activity however alternative origins for fusinite and semifusinite are still claimed this paper considers the use of the terms pyrofusinite degradofusinite rank fusinite and primary fusinite misleading while the definitions of the terms funginite and secretinite are also considered problematic observations made on modern wildfire derived and volcanogenic charcoal assemblages using reflectance and scanning electron microscopy together with experimental charcoalification studies demonstrate that most if not all inertinite macerals have acquired their optical and physical characteristics through the action of elevated temperatures the criteria for the identification of charcoals produced by wildfire and volcanic activity are outlined and the role of the petrographic nomenclature system is discussed

paleoenvironmental settings of the sofia lignite basin insights from coal petrography and molecular indicators abstract compositions of balsha lignite sofia coal bearing basin bulgaria and carbonaceous shales are studied by petrological and geochemical proxies the macropetrographic characteristic of profiles is relatively constant the lignite is generally composed of dull matrix coal containing significant amounts of xylite fragments the typical microscopic constituents of the lignite are the ulminite and less frequently textinite lenses scattered within attrinitic groundmass the maceral composition of the organic matter in carbonaceous shales does not differ significantly from that of the lignite samples biomarker assemblages of the extractable portions are determined by gas chromatography mass spectrometry additional information for the compositions of residues after extractions is obtained by tmah thermally assisted hydrolysis methylation petrographic contents lipid assemblage and tmah thermally assisted hydrolysis methylation data imply that the original peat bog is formed in fresh water forest swamp preferably composed by gymnosperms polar diterpenoids argue for cupressaceae s l taxodiaceae as the most probable vegetation for one of the profiles appreciable angiosperm rich herbaceous type flora contribution is assumed polar oleanane triterepenoids and their aromatized derivatives argue for angiosperm input the relevance of a norfriedel 8 en 10 one friedelin ratio for groundwater level appraisal is discussed it admits long period of high water level in the paleomire high content of vanillyl structures and subordinated presence of syringyl units in products of tmah thermally assisted hydrolysis methylation are hint for gymnospermae input in the paleoswamp and angiospermae contribution to one of the profiles cinnamyl phenolic units indicating non woody angiosperm vegetation presence are registered as well flavonoids in products are considered as taxonomic markers of cupressaceae plants in the paleoswamp

performance of high rate gps waveforms at long periods moment tensor inversion of the 2003 mw 8 3 tokachi oki earthquake abstract we present a comparison of long period 30 t m w 8 3 with both very broadband seismograms and synthetic waveforms we show that gps provides valuable waveform data between 40 and 160 s periods especially in the near field of the earthquake where seismograms are saturated there are no long period broadband seismic data available in the near field of large earthquakes 100 km for earthquakes m w 7 and 500 km for earthquakes m w 8 the comparison with synthetic seismic displacement waveforms shows that the gps waveforms are performing well at periods of 40 80 s at epicentral distances between 150 and 600 km and at periods of 80 160 s at epicentral distances between 150 and 400 km at longer periods and larger epicentral distances the amplitudes do not always exceed the noise level 2 3 mm but we still observe at selected gps sites that the phase and the amplitude of the surface waves are of good quality up to 1200 km we conclude that gps waveforms in the near field of a large event can be used for seismological applications in this article we recover the focal mechanism of the tokachi oki event by inverting the gps data recorded within 300 km of the epicenter

a study of hardness and fracture propagation in coal the surface hardness of coal was estimated using a shore scleroscope rebound hardness ssrh tester ssrh can be related to fracture toughness and strength and was trialled as a quick field test to illustrate variability in these properties for coal seam gas reservoirs therefore samples were selected to include different coal ranks and lithotypes from a suite of boreholes that intersect permian coal seams within the bowen basin in queensland australia the tests were conducted unconfined on slabbed coal core and confined on epoxy encased coal blocks used for coal petrographic examination the test results of the unconfined samples show that the hardness varies with lithotype it increases with decreasing amount of bright bands moreso than coal rank or thermal maturity the test results of the confined samples show little variation with lithotype but show a parabolic correlation of hardness with rank similar to the behaviour found with hardgrove grindability tests the resulting fractures of the ssrh test were analysed under the microscope to understand the fracture pattern which can be scaled up to understand fracture propagation in natural systems and when induced in gas reservoirs

the potential of high rate gps for strong ground motion assessment abstract we show that high rate global positioning system gps can have a vital role to play in near real time monitoring of potentially destructive earthquakes we do this by investigating the potential of gps in recording strong ground motions from earthquakes in switzerland and japan the study uses finite fault stochastic ground motion simulation based on fourier amplitude spectra and duration models previously developed for both countries allowing comparisons in terms of both fourier and time domain characteristics here the peak ground velocity pgv we find that earthquakes of magnitude m w 5 8 can be recorded by gps in real time at 10 km distance that is their fourier spectrum exceeds the noise of the instruments enough to be used in strong motion seismology postprocessing of gps time series lowers the noise and can improve the minimum observable magnitude by 0 1 0 2 as gps receivers can record at higher rates 10 hz we investigate which sampling rate is sufficient to optimally record earthquake signals and conclude that a minimum sampling rate of 5 hz is recommended this is driven by recording events at short distances below 10 km for magnitude 6 events and below 30 km for magnitude 7 events furthermore the maximum ground velocity derived from gps is compared with the actual pgv for synthetic signals from the stochastic simulations and the 2008 m w 6 9 iwate earthquake the proposed model confirmed by synthetic and empirical data shows that a reliable estimate of pgv for events of about magnitude 7 and greater can be basically retrieved by gps in real time and could be included for instance in shakemaps for aiding postevent disaster management

gps seismology application to the 2002 mw 7 9 denali fault earthquake abstract the 2002 denali fault alaska earthquake m w 7 9 caused one or more components of most broadband seismometers in western canada to clip yet did not trigger strong motion instruments thus leaving a substantial gap in the seismic record of this event however the large amplitude surface waves generated by this event were well recorded by the global positioning system gps in the same region out to epicentral distances of more than 3000 km in this article we explore the capabilities of gps seismology specifically how the relative strengths of gps and seismic data sets can be exploited in order to more effectively study earthquake source characteristics and wave propagation effects high rate 1 hz gps data from 23 stations throughout western north america have been analyzed to derive displacement waveforms for this event and the impact of instrumentation gps receiver model and error reduction strategy modified sidereal and spatial filtering on the noise characteristics of displacement time series at each gps site was assessed after applying error reduction methods to gps displacements the final average noise floors of 0 5 cm in the horizontal and 1 5 cm in the vertical indicate that large dynamic displacements are observable by gps we validate the gps displacements by comparing broadband seismic recordings integrated to displacement with gps recordings for four effectively colocated sets of instruments we show excellent agreement between the unclipped seismic and gps recordings of the surface waves from the denali earthquake over the period range of 10 50 sec and for ground displacements exceeding about 1 0 cm thus a large gps displacement data set is now available for western north america an area where records of this event were previously missing or incomplete the final gps seismograms are archived at incorporated research institutions for seismology iris for public use in future studies of the 2002 denali earthquake

advancement in source estimation techniques using broadband regional seismograms one important constraint on source retrieval from regional seismograms comes from the amplitude difference between various phases such as pnl surface wave sv sh because the misfit errors used in some waveform inversions are normalized by the data and synthetics the amplitude information in the data has not been fully utilized in this article we modify the cut and paste source estimation technique zhao and helmberger 1994 by removing this type of normalization it is shown that the modified method increases the stability and resolution of inversion when multiple stations at different distance ranges are used a distance scaling factor is introduced to compensate for the amplitude decay with distance by applying the technique to the terrascope data we have determined source mechanisms and depths of 335 southern californian events with m l 3 5 the amplitude decays with distance are r 1 13 for pnl r 0 55 for love waves and r 0 74 for rayleigh waves in contrast to generally shallow source depths reported by the southern california short period network the depth distribution from waveform inversion shows a strong peak around 12 km with few earthquakes occurring above 5 km and below 20 km

crustal deformation measurements in guerrero mexico 1 gps measurements of crustal deformation in guerrero southern mexico include surveys collected between 1992 and 2001 as well as continuous gps measurements at a few sites these geodetic observations are used to calculate interseismic deformation rates and assess the presence and possible location of transient deformation during the period encompassing 1992 25 to 2001 75 the data are used to examine transient deformation in 1998 previously described from data at a single site by lowry et al 2001 survey measurements and continuous data from a site near popocatepetl volcano confirm the 1998 transient and survey data also suggest another transient occurred following the 14 september 1995 mw 7 3 copala earthquake all of the available gps position estimates have been inverted for a combined model of slip during each event plus the steady state slip on the plate interface modeling of the steady state deformation rates confirms that the guerrero seismic gap is partially frictionally locked at depths shallower than about 25 km and accumulating strain that may eventually be released in a great earthquake the data also suggest that there is frictional coupling to much greater 40 km depths which releases more frequently in aseismic slip events the locations and sizes of the transient events are only partially constrained by the available data however the transient models which best fit the gps coordinate time series suggest that aseismic slip was centered downdip of the seismogenic portion of the plate bounding thrust in both events and the moment release had equivalent magnitudes mw 7 1 1 3 1 0 in 1995 1996 and 7 1 0 4 0 1 in 1998

the 2010 m w 7 2 el mayor cucapah earthquake sequence baja california mexico and southernmost california usa active seismotectonics along the mexican pacific margin the el mayor cucapah earthquake sequence started with a few foreshocks in march 2010 and a second sequence of 15 foreshocks of m 2 up to m4 4 that occurred during the 24 h preceding the mainshock the foreshocks occurred along a north south trend near the mainshock epicenter the mw 7 2 mainshock on april 4 exhibited complex faulting possibly starting with a m6 normal faulting event followed 15 s later by the main event which included simultaneous normal and right lateral strike slip faulting the aftershock zone extends for 120 km from the south end of the elsinore fault zone north of the us mexico border almost to the northern tip of the gulf of california the waveform relocated aftershocks form two abutting clusters each about 50 km long as well as a 10 km north south aftershock zone just north of the epicenter of the mainshock even though the baja california data are included the magnitude of completeness and the hypocentral errors increase gradually with distance south of the international border the spatial distribution of large aftershocks is asymmetric with five m5 aftershocks located to the south of the mainshock and only one m5 7 aftershock but numerous smaller aftershocks to the north further the northwest aftershock cluster exhibits complex faulting on both northwest and northeast planes thus the aftershocks also express a complex pattern of stress release along strike the overall rate of decay of the aftershocks is similar to the rate of decay of a generic california aftershock sequence in addition some triggered seismicity was recorded along the elsinore and san jacinto faults to the north but significant northward migration of aftershocks has not occurred the synthesis of the el mayor cucapah sequence reveals transtensional regional tectonics including the westward growth of the mexicali valley and the transfer of pacific north america plate motion from the gulf of california in the south into the southernmost san andreas fault system to the north we propose that the location of the 2010 el mayor cucapah as well as the 1992 landers and 1999 hector mine earthquakes may have been controlled by the bends in the plate boundary

organic petrology and coalbed gas content wilcox group paleocene eocene northern louisiana abstract wilcox group paleocene eocene coal and carbonaceous shale samples collected from four coalbed methane test wells in northern louisiana were characterized through an integrated analytical program organic petrographic analyses gas desorption and adsorption isotherm measurements and proximate ultimate analyses were conducted to provide insight into conditions of peat deposition and the relationships between coal composition rank and coalbed gas storage characteristics the results of petrographic analyses indicate that woody precursor materials were more abundant in stratigraphically higher coal zones in one of the cbm wells consistent with progradation of a deltaic depositional system holly springs delta complex into the gulf of mexico during the paleocene eocene comparison of petrographic analyses with gas desorption measurements suggests that there is not a direct relationship between coal type sensu maceral composition and coalbed gas storage moisture as a function of coal rank lignite subbituminous a exhibits an inverse relationship with measured gas content this result may be due to higher moisture content competing for adsorption space with coalbed gas in shallower lower rank samples shallower 600 m coal samples containing less moisture range from under to oversaturated with respect to their ch4 adsorption capacity

organic facies and depositional palaeoenvironment of lignites from rio maior basin portugal abstract the rio maior basin portugal is a tectonic depression filled by a pliocene sequence that comprises from floor to roof i kaoliniferous fine sands ii diatomites and lignites iii recent deposits of sandstone and clay the diatomites and lignites form a small dissimetric syncline with alternating seams ten lignite seams were identified and named from floor to roof as f e d c 2 c 1 c b a a and a seams a d e and f are considered to be the main seams the organic fraction consists mainly of macerals of the huminite group with small percentages of inertinite and liptinite groups however the petrographic composition of each seam is distinct particularly with regards to macerals of the huminite and liptinite groups calculation of petrographic indices permitted to plot the coals in facies and palaeoenvironment diagrams five facies have been defined i aquatic ii herbaceous swamp iii mixed swamp with forest and herbaceous vegetation vi forest swamp wetter and v forest swamp drier these lignites are humic coals formed from organic matter of terrestrial origin the peat biomass at the origin of these coals formed from a very diverse vegetation comprising gymnosperms and angiosperms in seams f and occasionally in seams e and d botryococcus algae have also contributed to the biomass peat deposition corresponded to a rheotrophic hydrological regime the water level always remained above the topographic surface of the basin nevertheless during the deposition of seam a in the northern part of the basin the water level was slightly below the topographic surface the organic matter was preserved in anaeorobic conditions

present day crustal deformation in china constrained by global positioning system measurements global positioning system gps measurements in china indicate that crustal shortening accommodates most of india s penetration into eurasia deformation within the tibetan plateau and its margins the himalaya the altyn tagh and the qilian shan absorbs more than 90 of the relative motion between the indian and eurasian plates internal shortening of the tibetan plateau itself accounts for more than one third of the total convergence however the tibetan plateau south of the kunlun and ganzi mani faults is moving eastward relative to both india and eurasia this movement is accommodated through rotation of material around the eastern syntaxis the north china and south china blocks east of the tibetan plateau move coherently east southeastward at rates of 2 to 8 millimeters per year and 6 to 11 millimeters per year respectively with respect to the stable eurasia

palaeoenvironment of seam i in the marathousa lignite mine megalopolis basin southern greece the present study aims to elucidate the depositional environment of seam i in the megalopolis basin southern greece using existing geological data supported by maceral and mineralogical analyses as well as by natural radioactivity determinations very high pyrite and uranium contents and a very low tissue preservation index usually suggest a marine influence during deposition in seam i however these features are most probably the result of a karstic aquifer supplying the palaeomire with sulphate rich neutral to weakly alkaline water the pyrite formation and the u precipitation are attributed to the anaerobic conditions which prevailed during peat accumulation the petrographic mineralogical and geochemical data of the studied profile point to several changes in the surface runoff and the supply of clastic material during deposition

modeling the rupture process of the 2003 september 25 tokachi oki hokkaido earthquake using 1 hz gps data received 10 september 2004 accepted 3 october 2004 published 3 november 2004 1 high rategpshasthepotentialtorecoverbothdynamic and static displacements accurately we analyze 1 hz gps data recorded during the 2003 tokachi oki earthquake the 1 hz gps displacement waveforms show good agreement with integrated accelerometer records except for low frequency noise that are inherently present in integrated seismic records the gps waveforms were inverted to model the spatio temporal evolution of the fault slip during the rupture the slip is found to propagate downdip in the subduction zone with largest moment release 50 km northwest of the hypocenter the region of largest slip agrees in general with traditional seismic studies indicating that 1 hz gps can be used for finite fault studies the 1 hz gps slip model shows clearer contrast with afterslip distributions than those inferred from strong motion data possibly because 1 hz gps is more sensitive to cumulative slip distribution index terms 1294 geodesy and gravity instruments and techniques 7209 seismology earthquake dynamics and mechanics 7212 seismology earthquake ground motions and engineering citation miyazaki s k m larson k choi k hikima k koketsu p bodin j haase g emore and a yamagiwa 2004 modeling the rupture process of the 2003 september 25 tokachi oki hokkaido earthquake using 1 hz gps data geophys res lett 31 l21603 doi 10 1029 2004gl021457

spatio temporal distribution of fault slip and high frequency radiation of the 2010 el mayor cucapah mexico earthquake 1 earthquake slip history and moment release are best resolved using long period seismic waves but details in the rupture process such as sharp changes in rupture velocity or direction can be imaged more clearly using higher frequency waves here we investigate the slip and the high frequency radiation histories of the 2010 el mayor cucapah baja california mexico earthquake mw 7 2 the slip distribution inferred from inversion of strong motion data between 0 02 and 0 25 hz indicates northwest propagating rupture followed by bilateral rupture for 40 s the sources of high frequency radiation between 0 3 and 2 hz inferred from back projection analysis using teleseismic data are adjacent to but not within the high slip patches from the finite slip model in time and space this implies relatively smooth rupture during the times and regions of maximum moment release as theoretical models have predicted high frequency radiation seems mostly associated with changes in rupture velocity or slip magnitude strong high frequency radiation is also found where the rupture propagated to a branch fault 50 km northwest of the hypocenter complementary constraints on both fault slip and high frequency radiation provide increased understanding of earthquake rupture mechanics and may help improve strong motion evaluation at high frequencies

superficial simplicity of the 2010 el mayor cucapah earthquake of baja california in mexico the geometry of faults is usually thought to be more complicated at the surface than at depth and to control the initiation propagation and arrest of seismic ruptures the fault system that runs from southern california into mexico is a simple strike slip boundary the west side of california and mexico moves northwards with respect to the east however the m w 7 2 2010 el mayor cucapah earthquake on this fault system produced a pattern of seismic waves that indicates a far more complex source than slip on a planar strike slip fault here we use geodetic remote sensing and seismological data to reconstruct the fault geometry and history of slip during this earthquake we find that the earthquake produced a straight 120 km long fault trace that cut through the cucapah mountain range and across the colorado river delta however at depth the fault is made up of two different segments connected by a small extensional fault both segments strike n130 e but dip in opposite directions the earthquake was initiated on the connecting extensional fault and 15 s later ruptured the two main segments with dominantly strike slip motion we show that complexities in the fault geometry at depth explain well the complex pattern of radiated seismic waves we conclude that the location and detailed characteristics of the earthquake could not have been anticipated on the basis of observations of surface geology alone

hydrocarbon generation potential and miocene pliocene paleoenvironments of the kangal basin central anatolia turkey abstract this study deals with the organic geochemical characteristics hydrocarbon generative potential and miocene pliocene paleoenvironments of the kangal coal district which developed in a limnic depositional environment and contains the hamal etyemez and kalburcayiri coal fields in the southern part of the sivas basin central anatolia around kalburcayiri the average thickness of each of the two coal seams approximately 10 m are currently being exploited based on open cast methods the coal from which is used by the nearby lignite fired kangal power station an attempt was made to elucidate depositional conditions through proximate and ultimate analyses coal petrography and the geochemical characteristics of the kangal coals these coals have a huminite reflectance value of rmax 0 40 accordingly from the standpoint of coal rank this is a dull brown coal of the subbituminous c type huminite is the most widespread maceral type while gelinites are the most often encountered macerals relative to liptinites the proportion of inertinites is high on the basis of maceral composition the depositional environment of the kangal coals was determined to be either a forest swamp or a lake bottom the distributions of the c27 and c28 c29 steranes for all these coal samples are very similar c29 c27 c28 tricyclic terpanes have low concentrations in all samples of the kangal coals and are dominated by low molecular weight compounds c20 c24 with a maximum at c23 total organic carbon toc wt values of the kalburcayiri samples are 4 64 30 64 wt in the hamal samples 0 83 2 53 wt and in the etyemez samples 8 91 10 39 wt on the basis of tmax values the samples are in the immature early mature stage according to rock eval pyrolysis data the coals have hydrocarbon source rock potential but the coaly shales and other organic matter rich levels have no hydrocarbon source rock potential the high inertinite levels and high vitrinite inertinite ratios suggest that the kangal coals have more potential for gas generation than oil

global plate velocities from the global positioning system we have analyzed 204 days of global positioning system gps data from the global gps network spanning january 1991 through march 1996 on the basis of these gps coordinate solutions we have estimated velocities for 38 sites mostly located on the interiors of the africa antarctica australia eurasia nazca north america pacific and south america plates the uncertainties of the horizontal velocity components range from 1 2 to 5 0 mm yr with the exception of sites on the pacific and nazca plates the gps velocities agree with absolute plate model predictions within 95 confidence for most of the sites in north america antarctica and eurasia the agreement is better than 2 mm yr we find no persuasive evidence for significant vertical motions 3 standard deviations except at four sites three of these four were sites constrained to geodetic reference frame velocities the gps velocities were then used to estimate angular velocities for eight tectonic plates absolute angular velocities derived from the gps data agree with the no net rotation nnr nuvel 1a model within 95 confidence except for the pacific plate our pole of rotation for the pacific plate lies 11 5 west of the nnr nuvel 1a pole with an angular speed 10 faster our relative angular velocities agree with nuvel 1a except for some involving the pacific plate while our pacific north america angular velocity differs significantly from nuvel 1a our model and nuvel 1a predict very small differences in relative motion along the pacific north america plate boundary itself our pacific australia and pacific eurasia angular velocities are significantly faster than nuvel 1a predicting more rapid convergence at these two plate boundaries along the east pacific rise our pacific nazca angular velocity agrees in both rate and azimuth with nuvel 1a

organic geochemical and petrographic characteristics of tertiary coals in the northwest sarawak malaysia implications for palaeoenvironmental conditions and hydrocarbon generation potential abstract tertiary coals from mukah and balingian coalfields in the northwest sarawak malaysia were investigated to evaluate their regional rank variation petroleum generative potential and to reconstruct the palaeoenvironment conditions during peat accumulation the tertiary coals are characterized by high total organic carbon contents toc and yield of bitumen extraction ranging from 31 3 to 55 9 wt and 25 724 9 92 143 7 ppm respectively meet the standard as a good source rock potential the mukah and balingian coals were generally plotted in an area of type iii kerogen and mixed type ii iii kerogens with hi values between 90 and 289 mg hc g toc whereby the coals were derived from plant materials of terrigenous origin this shows that the balingian coals are dominated by type iii terrigenous kerogen while mukah coals are dominated by type ii iii kerogens and are thus considered to be generate mainly gas prone and limited oil prone this is also supported by macerals composition and open system pyrolysis gas chromatography py gc the mukah and balingian coals are thermally immature in rang from lignite to sub bituminous c rank possessing huminite reflectance in the range of 0 26 0 39 this immaturity has a considerable influence on the proximate analysis particularly on relatively high moisture and volatile matter contents and relatively low fixed carbon content petrographically it was observed that the mukah and balingian coals are dominated by huminite with low to high amounts of liptinite and relatively low amounts of inertinite pointing to predominantly anaerobic deposition conditions in the paleomires with limited thermal and oxidative tissue destruction the palaeoenvironment conditions of the coals are generally interpreted as a lower deltaic plain wet peat swamp depositional setting which are generally characterised by low tpi and high gi values and are plotted on the marsh field of the diessel s diagram this is usually consistent with generate relatively high ash yield as is the case of the mukah and balingian coals

real time centroid moment tensor determination for large earthquakes from local and regional displacement records summary we present an algorithm to rapidly determine the moment tensor and centroid location for large earthquakes employing local and regional real time high rate displacement records from gps the algorithm extracts the coseismic offset from the displacement waveforms and uses the information to invert for the moment tensor the green s functions for a layered earth are obtained numerically from open source code edgrn to determine the centroid multiple inversions are simultaneously performed within a grid of inversion nodes and the node with the smallest misfit is then assigned the centroid location we show results for two large earthquakes replayed in simulated real time mode using recorded 1 hz gps displacements the 2003 mw 8 3 tokachi oki and the 2010 mw 7 2 el mayor cucapah earthquakes we demonstrate that it is feasible to obtain accurate cmt solutions within the first 2 3 min after rupture initiation without any prior assumptions on fault characteristics demonstrating an order of magnitude improvement in latency compared to existing seismic methods for the two earthquakes studied this methodology is useful for rapid earthquake response tsunami prediction and as a starting point for rapid finite fault modelling

using 1 hz gps data to measure deformations caused by the denali fault earthquake the 3 november 2002 moment magnitude 7 9 denali fault earthquake generated large permanent surface displacements in alaska and large amplitude surface waves throughout western north america we find good agreement between strong ground motion records integrated to displacement and 1 hertz global positioning system gps position estimates collected 140 kilometers from the earthquake epicenter one hertz gps receivers also detected seismic surface waves 750 to 3800 kilometers from the epicenter whereas these waves saturated many of the seismicinstruments in the same region high frequency gps increases the dynamic range and frequency bandwidth of ground motion observations providing another tool for studying earthquake processes

locating and modeling regional earthquakes with two stations 1 we developed a new technique caploc to retrieve full source parameters of small seismic events from regional seismograms which include origin time epicenter location depth focal mechanism and moment magnitude despite rather complicated propagation effects at short periods a simple localized one dimensional model can well explain signals of periods 3 10 s if we break the three component records into different segments and allow differential time shifts among them these differential time shifts once established from a calibration process or a well determined tomographic map can be used together with p wave travel times to refine an event s location in this study we tested whether our new method could produce satisfactory results with as few as two stations so that we can improve source estimates of poorly monitored events with sparse waveform data we conducted the test on 28 events in the tibetan plateau the focal mechanisms and locations determined from only two stations agree well with those determined from a whole passcal array in particular our new method produces better locations than international seismological centre with the average mislocation error reduced from 16 to 5 km we also tested whether an event s depth and mechanism can be determined separately from its epicenter relocation in a two step approach we find that the two step approach does not always give the correct solution but the reliability of a solution can be evaluated using a reduced chi square value

5hz gps seismology of the el mayor cucapah earthquake estimating the earthquake focal mechanism summary high rate 5hz gps records observed in the near field following the magnitude 7 2 el mayor cucapah earthquake that occurred in northern mexico on 2010 april 4 are compared with broad band seismograms the high rate gps displacement records are consistent with the twice integrated strong motion seismic records in the near field where broad band seismograms are clipped due to strong shaking agreement degrades at distances greater than about 150 km from the epicentre where displacement amplitudes approach the noise level of gps seismograms using high rate gps data the focal mechanism of the main shock is estimated and is shown to be consistent with teleseismic estimates the result is seen as confirmation that high rate gps observed at near field stations can be applied together with teleseismic seismometers to yield better information about earthquake rupture properties and parameters

application of real time gps to earthquake early warning 1 we explore the use of real time high rate gps displacement data for earthquake early warning using 1 hz displacement waveforms from the april 4 2010 mw 7 2 el mayor cucapah earthquake we compare these data to those provided by the broadband velocity and accelerometer instrumentation of the southern california seismic network the unique information provided by the gps based displacement timeseries is the permanent static displacement using a simple algorithm that can be applied in real time we extract the static offset shortly after the s wave arrival around the time of the observed peak shaking at the same site and before shaking at more distant locations these data can be used as they become available to provide a robust estimate of the earthquake magnitude which ranges from 6 8 to 7 0 in this case we therefore conclude that real time high rate gps can provide a useful and independent assessment of earthquake magnitude for the purpose of earthquake early warning and real time earthquake information systems in general including tsunami warning systems

microfacies and depositional environment of tertiary tanjung enim low rank coal south sumatra basin indonesia abstract the south sumatra basin is among the most important coal producing basins in indonesia results of an organic petrography study on coals from tanjung enim south sumatra basin are reported the studied low rank coals have a mean random huminite reflectance between 0 35 and 0 46 and are dominated by huminite 34 6 94 6 vol less abundant are liptinite 4 0 61 4 vol and inertinite 0 2 43 9 vol minerals are found only in small amounts 0 2 vol mostly as iron sulfide based on maceral assemblages the coals can be grouped into five classes 1 humotelinite rich group 2 humodetrinite rich group 3 humocollinite rich group 4 inertinite rich group and 5 humodetrinite liptinite rich group comparing the distribution of maceral assemblages to the maceral or pre maceral assemblages in modern tropical domed peat in indonesia reveals many similarities the basal section of the studied coal seams is represented typically by the humodetrinite liptinite rich group this section might be derived from sapric or fine hemic peat often occurring at the base of modern peats the middle section of the seams is characterized by humotelinite rich and humocollinite rich groups the precursors of these groups were hemic and fine hemic peats the top section of the coal seams is typically represented by the humodetrinite rich or inertinite rich group these groups are the counterparts of fibric peat at the top of the modern peats the sequence of maceral assemblages thus represents the change of topogenous to ombrogenous peat and the development of a raised peat bog a comparison between the result of detailed maceral assemblage analysis and the paleodepositional environment as established from coal maceral ratio calculation indicates that the use of coal maceral ratio diagrams developed for other coal deposits fails to deduce paleo peat development for these young tropical coals in particular mineral distribution and composition should not be neglected in coal facies interpretations

slip history of the 2003 san simeon earthquake constrained by combining 1 hz gps strong motion and teleseismic data 1 the slip history of the 2003 san simeon earthquake is constrained by combining strong motion and teleseismic data along with gps static offsets and 1 hz gps observations comparisons of a 1 hz gps time series and a co located strong motion data are in very good agreement demonstrating a new application of gps the inversion results for this event indicate that the rupture initiated at a depth of 8 5 km and propagated southeastwards with a speed 3 0 km sec with rake vectors forming a fan structure around the hypocenter we obtained a peak slip of 2 8 m and total seismic moment of 6 2 10 18 nm we interpret the slip distribution as indicating that the hanging wall rotates relative to the footwall around the hypocenter in a sense that appears consistent with the shape of the mapped fault trace index terms 1242 geodesy and gravity seismic deformations 7205 7212 seismology earthquake ground motions and engineering 8123 tectonophysics dynamics seismotectonics citation ji c k m larson y tan k w hudnut and k choi 2004 slip history of the 2003 san simeon earthquake constrained by combining 1 hz gps strong motion and teleseismic data geophys res lett 31 l17608 doi 10 1029 2004gl020448

ability of 1 hz gps data to infer the source process of a medium sized earthquake the case of the 2008 iwate miyagi nairiku japan earthquake 1 we demonstrate the ability of 1 hz global positioning system gps data to infer a medium sized m6 class earthquake source process through an inversion study of the 2008 iwate miyagi nairiku japan earthquake m 6 9 1 hz gps waveforms for this earthquake are compared and show good agreement with strong motion waveforms ground motions are well recorded at a sufficient number of gps stations in and around source region allowing us to perform waveform inversion using 1 hz gps data only the 1 hz gps inversion result shows fairly good agreement with a joint inversion of geodetic and strong motion data such as the seismic moment mw 6 9 cumulative slip distribution and rupture propagation such agreements demonstrate that 1 hz gps is able to infer the dynamic features of the rupture process as well as permanent or static slip even for a m6 class medium sized earthquake

effect of baseline corrections on displacements and response spectra for several recordings of the 1999 chi chi taiwan earthquake displacements derived from many of the accelerogram recordings of the 1999 chi chi taiwan earthquake show drifts when only a simple baseline de rived from the pre event portion of the record is removed from the records the appearance of the velocity and displacement records suggests that changes in the zero level of the acceleration are responsible for these drifts the source of the shifts in zero level are unknown but in at least one case it is almost certainly due to tilting of the ground this article illustrates the effect on the ground velocity ground dis placement and response spectra of several schemes for accounting for these baseline shifts a wide range of final displacements can be obtained for various choices of baseline correction and comparison with nearby gps stations none of which are colocated with the accelerograph stations do not help in choosing the appropriate baseline correction the results suggest that final displacements estimated from the records should be used with caution the most important conclusion for earthquake engineering purposes however is that the response spectra for periods less than about 20 sec are usually unaffected by the baseline correction although limited to the analysis of only a small number of recordings the results may have more general significance both for the many other recordings of this earthquake and for data that will be obtained in the future from similar high quality accelerograph networks now being installed or soon to be installed in many parts of the world

comparisons of ground motions from colocated and closely spaced one sample per second global positioning system and accelerograph recordings of the 2003 m 6 5 san simeon california earthquake in the parkfield region the 2003 san simeon california earthquake m 6 5 generated a set of colocated and closely spaced high rate 1 sample per second global positioning system gps positions and ground motions from digital accelerographs in the park field region at epicentral distances of 50 to 70 km the waveforms of displacements derived from the 13 gps receivers in the region have dominant periods between about 7 and 18 sec the waveforms are similar in shape with a systematic change in waveform as a function of distance from the source the gps motions are smaller than the accelerograph motions for periods less than about 2 sec from this we conclude that the 1 sample per sec gps receivers provide a good representation of ground motion at periods longer than about 2 sec perhaps more important for earth quake engineering is that the accelerograph data are similar to the gps data for periods as long as 30 sec if not longer this means that data from digital accelero graphs can provide reliable relative displacement response spectra at the periods needed in the design of large structures at least for earthquakes with magnitudes of 6 5 or above at distances within 70 km we combine the colocated or very closely spaced gps and accelerograph data sets in the frequency domain to obtain a single broadband time series of the ground motion at each accelerograph station these broadband ground motions may be useful to seismologists in unraveling the dynamic process of fault rupture and to engineers for designing large structures with very long period response

instantaneous geodetic positioning at medium distances with the global positioning system we evaluate a new method of global positioning system gps data analysis called instantaneous positioning at spatial scale lengths typical of interstation spacings in a modern crustal motion network this method is more precise and versatile than traditional gps static and kinematic processing of multi epoch batches of data the key to instantaneous positioning is the ability to resolve integer cycle phase ambiguities with only a single epoch of dual frequency phase and pseudorange data rendering receiver cycle slips irrelevant we estimate three dimensional relative coordinates and atmospheric zenith delay parameters independently every 30 s over a 12 week period for baseline distances of 50 m 14 km and 37 km horizontal precision of a single epoch coordinate solution is about 15 mm and vertical precision is about 7 8 times worse removing that component of each time series which repeats with a period of exactly 1 sidereal day and thus manifests signal multipath reduces the scatter by about 50 in all components solution averaging of the high frequency time series can be performed using any number of measurement epochs to further improve coordinate precision we demonstrate that the daily coordinates estimated with instantaneous positioning are more precise by 20 50 per coordinate component than those estimated with 24 hour batch processing spectral analysis of the single epoch solutions indicates that the flicker noise characteristic of gps time series observed in lower frequency bands also affects gps solutions in the frequency band 0 01 mhz to 10 mhz we argue that the flicker noise is induced by tropospheric effects since modern gps receivers are capable of observing at frequencies as high as 10 hz our technique significantly overlaps and complements the frequency band of broadband seismology and benefits other research areas such as earthquake geodesy volcanology and gps meteorology

rapid resolution of crustal motion at short ranges with the global positioning system on the basis of the analysis of global positioning system gps data collected at the u s geological survey kennedy ranch house alinement array near parkfield california in november 1990 and february 1991 we assess the temporal resolution of crustal deformation for gps receiver systems operating as strain meters and provide guidelines for achieving millimeter level precision with short range kinematic type gps measurements site occupation of about one half hour is sufficient for day to day repeatability of submillimeter precision in relative position during good satellite geometry signal multipath effects which dominate dispersive baseline errors are essentially averaged out and need not be modeled however as occupation times decrease baseline solutions are increasingly sensitive to multipath effects which together with nondispersive receiver measurement noise are of millimeter to centimeter magnitude in epoch by epoch solutions on repeatedly monitored baselines we can account for both of these noise sources separately the mostly random receiver noise is effectively suppressed by low pass filters with corner frequencies of about 20 mhz the multipath noise is filtered using the fact that it essentially repeats from day to day residual errors in filtered 1 s epoch by epoch solutions are below 2 mm during periods of good satellite geometry hence for a continuously monitored baseline actual deformation in excess of this threshold can be detected with a time lag comparable to the group delay of the low pass filter i e typically within a minute in terms of strain along a typical short baseline of 1 km sampled once per second we can detect 1 2 s in l min with multipath modeling without multipath modeling it takes 10 min to resolve the same magnitude of deformation in 30 min we can detect 0 1 s independent of multipath modeling these results have important implications for kinematic type gps surveys for millimeter level precision without impractical multipath modeling it is necessary to occupy a site during good satellite geometry for a period longer than that of the multipath signature our experience in both benign and difficult multipath environments indicates that approximately 10 min are sufficient the measurements at the kennedy ranch house alinement array suggest that this segment of the san andreas fault appears to be virtually locked at the surface during the 3 month period between the two surveys

rapid determination of earthquake magnitude using gps for tsunami warning systems 1 the 26 december 2004 sumatra earthquake mw 9 2 9 3 generated the most deadly tsunami in history yet within the first hour the true danger of a major oceanwide tsunami was not indicated by seismic magnitude estimates which were far too low mw 8 0 8 5 this problem relates to the inherent saturation of early seismic wave methods here we show that the earthquake s true size and tsunami potential can be determined using global positioning system gps data up to only 15 min after earthquake initiation by tracking the mean displacement of the earth s surface associated with the arrival of seismic waves within minutes displacements of 10 mm are detectable as far away as india consistent with results using weeks of data after the event these displacements imply mw 9 0 0 1 indicating a high tsunami potential this suggests existing gps infrastructure could be developed into an effective component of tsunami warning systems

gps applications for geodynamics and earthquake studies geodetic measurements obtained with the global positioning system gps are increasingly more widely applied in geophysical studies in this paper we review the changes to the technology of gps geodesy over the last five years that are responsible for this increased applicability we survey geophysical investigations employing gps to measure coseismic postseismic and interseismic deformation plate motion and crustal deformation at plate boundaries volcano deformation and the deformation associated with glacial isostatic adjustment and its application to sea level studies we emphasize the use of gps determinations for the modeling of this wide variety of geophysical phenomena we also discuss the recent advent of permanent gps networks for regional geophysical studies as well as the possible future of gps surveying in light of the recent advances