chemical and physical studies of type 3 chondrites ix thermoluminescence and hydrothermal annealing experiments and their relationship to metamorphism and aqueous alteration in type 3 3 ordinary chondrites samples of four type 3 chondrites have been annealed at 400 850 c and 0 77 1 kbar for 10 500 h in the presence of various amounts of water 0 10 wt and sodium disilicate 0 2 molal and their thermoluminescence properties measured after annealing for 20 h at temperatures 600 c the tl sensitivity of the samples increased by factors of up to 40 after annealing at 800 c when both high and low forms were present originally the low form was destroyed preferentially we suggest that these data are consistent with the tl metamorphism trends observed in type 3 2 chondrites being due to the formation of feldspar with structural details being dependent on formation temperature by the devitrification of chondrule glass during metamorphism for types 3 2 the tl data are equally consistent with these types experiencing lower levels of metamorphism than the higher types or with type 3 0 being produced from higher types by aqueous alteration the presence of water with non terrestrial d h ratios and petrographic evidence for aqueous alteration in semarkona lead us to favour the aqueous alteration hypothesis

the detection of low magnitude seismic events using array based waveform correlation summary it has long been accepted that occurrences of a known signal are most effectively detected by cross correlating the incoming data stream with a waveform template such matched signal detectors have received very little attention in the field of detection seismology because there are relatively few instances in which the form of an anticipated seismic signal is known a priori repeating events in highly confined geographical regions have been observed to produce very similar waveforms and good signals from events at a given site can be exploited to detect subsequent co located events at lower magnitudes than would be possible using traditional power detectors even greater improvement in signal detectability can be achieved using seismic arrays running correlation coefficients from single sensors can be stacked over an array or network to result in a network correlation coefficient displaying a significant array gain if two events are co located the time separating the corresponding patterns in the wave train as indicated by the cross correlation function is identical for all seismic stations and this property means that the correlation coefficient traces are coherent even when the waveforms are not we illustrate the power of array based waveform correlation using the 1997 august 16 kara sea event the weak event that occurred 4 hr after the main event was barely detected using an sta lta detector on the spits array but is readily detected by signal matching on a single channel the main event was also recorded by the far more distant norsar array but no conventional detection can be made for the second event a clear detection is however made when the correlation coefficient traces are beamformed over all sensors of the array we estimate the reduction in detection threshold of a test signal on a regional seismic array using waveform correlation by scaling down a master signal and immersing it into seismic noise we show that for this case waveform correlation using a single channel detects signals of approximately 0 7 orders of magnitude lower than is possible using an sta lta detector on the array beam waveform matching on the full array provides an additional improvement of approximately 0 4 magnitude units we describe a case study in which small seismic events at the barentsburg coal mine on spitsbergen were detected using the signals from a major rockburst as master waveforms many spurious triggers occurred in this study whereby short sections of signal exhibited coincidental similarity with unrelated incoming wave fronts we demonstrate how such false alarms can almost always be identified and screened out automatically by performing frequency wavenumber analysis upon the set of individual correlation coefficient traces

planetary wave and gravity wave influence on the occurrence of polar stratospheric clouds over davis station antarctica seen in lidar and radiosonde observations 1 we present rayleigh lidar observations of polar stratospheric clouds psc from davis station 68 6 s 78 0 e antarctica from the 2001 2002 2003 and 2004 austral winter seasons the psc are detected as enhanced backscatter returns at lower stratospheric heights we use operational radiosonde balloon data to compare the psc detections with stratospheric temperature and wave properties as documented by others we find that the occurrence of psc is closely tied to average stratospheric temperatures which in turn are closely related to the location of davis with respect to the antarctic vortex with psc being seen when the temperature falls to near or below the calculated formation temperature of nitric acid trihydrate there is clear evidence in the sonde data for gravity wave and planetary wave modulation of the stratospheric temperature we see small scale wavelike structure in the psc profiles which likely arises from gravity waves but find little direct correlation between a given vertical lidar psc profile and near contemporaneous sonde profile probably because the sonde flight is not an instantaneous sounding at the exact spatial location of the lidar the planetary wave induced temperature variations are of the order of 10 times the size of the gravity wave variations and have a greater and more direct influence in psc occurrence over davis

the effect of orographic gravity waves on antarctic polar stratospheric cloud occurrence and composition 1 a seasonal analysis of the relationship between mesoscale orographic gravity wave activity and polar stratospheric cloud psc composition occurrence around the whole of antarctica is presented gravity wave variances are derived from temperature measurements made with the constellation observing system for meteorology ionosphere and climate cosmic global positioning system radio occultation gps ro satellites data from the cloud aerosol lidar with orthogonal polarization caliop instrument onboard the cloud aerosol lidar and infrared pathfinder satellite observations calipso satellite are used to determine the psc composition class distribution and spatial volume the results show intermittent large wave activity above the antarctic peninsula which is coincident with large volumes of h2o ice pscs these ice psc volumes advect downstream where increases in nitric acid trihydrate nat psc volumes occur supporting the mountain wave seeding hypothesis during winter 2007 in the latitude range 60 s 70 s near the edge of the vortex and where temperatures are close to psc formation thresholds 30 of all pscs are attributable to orographic gravity waves in the separate composition classes around 50 of both h2o ice pscs and a high nat number density liquid nat mixture class of pscs are due to these waves while we show that planetary waves are the major determinant of psc presence at temperatures close to the nat formation threshold we also demonstrate the important role of mesoscale intermittent orographic gravity wave activity in accounting for the composition and distribution of pscs around antarctica

cumberland falls chondritic inclusions iii consortium study of relationship to inclusions in allan hills 78113 aubrite abstract we describe the mineralogy and report contents of ag au bi cd co cs ga in rb sb se te tl u and zn determined by rnaa in three primitive chondritic inclusions from the alh a78113 aubrite comparison of these data with those for large petrologic type 3 chondritic clasts from the cumberland falls aubrite and the discovery of small clasts in it like those in alh a78113 indicate that all constitute a single chondritic suite we also report thermoluminescence data for cumberland falls chondritic inclusions and achondritic host these results together with mineralogie major minor and trace element information demonstrate that aubrite inclusions represent a different sort of type 3 chondrite not an ll3 chondrite altered during equilibration with aubrite host instead the aubrite inclusions represent a distinct chondrite class these inclusions reflect nebular condensation accretion over a broad redox range and at temperatures relatively high compared with those at which other type 3 chondrites formed limited metamorphism and reduction occurred during condensation accretion prior to incorporation into aubrite host during the impact of the chondritic parent body with the aubrite parent body chondrite fragments were strongly shocked and cooled rapidly they then mixed with aubrite host possibly in a regolith so that these aubrites now represent impact breccias

discriminating quarry blasts from earthquakes using coda waves abstract a new quarry blast earthquake discrimination method is presented based on the analysis of seismic coda waves quarry blasts and local earthquakes in the area encompassing the south central mojave desert and eastern transverse ranges were used to test this method we found that the coda decay rate q c 1 is significantly higher for quarry blasts than earthquakes for lower frequencies 1 5 and 3 hz for lapse time up to about 30 sec this result is attributed to the greater contribution of surface waves to quarry blasts due to the shallowness of their source depth the difference in q c 1 however disappears for lapse time greater than 30 sec for the same frequency range as well as for higher frequencies 6 and 12 hz for lapse time greater than 20 sec this suggests that the coda waves at the lapse time greater than these critical values are dominated by the same type of body waves probably s waves for both quarry blasts and earthquakes the power spectrum p 0 obtained after the correction for attenuation was compared between earthquakes and quarry blasts at the same stations and a significant difference was found in the spectral shape between these two data sets the curves of power spectrum p 0 versus frequency for quarry blasts decrease more sharply than for earthquakes at high frequencies indicating a lack of energy in high frequencies for quarry blasts as compared to earthquakes the different frequency dependence of power spectrum p 0 between quarry blasts and earthquakes is attributed to their different source properties and can be used for seismic discrimination of quarry blasts from earthquakes

thermoluminescence and compositional zoning in the mesostasis of a semarkona group a1 chondrule and new insights into the chondrule forming process a large group a1 porphyritic olivine chondrule in the semarkona ll3 0 chondrite with induced thermoluminescence tl and compositional zoning in its mesostasis has been discovered the chondrule has ca rich and fe poor olivine cao 0 36 0 40 wt fa0 3 0 5 and its mesostasis is highly anorthite normative 52 5 wt the chondrule shows an intense induced tl peak at 300 c with a half width of 180 c the induced tl in the 40 440 c range increases monotonically by a factor of 6 from center to rim while sio2 na2o and mno increase by factors of 1 1 3 6 and 6 respectively the spectrum of the induced tl over the 200 350 c range i e a dominant peak at 570 nm with a half width of about 100 nm and the mn tl correlation suggest mn activated plagioclase is an important constituent of the refractory mesostases in group a1 chondrules the zoning may reflect fractional crystallization soret diffusion transport of volatiles into the chondrule by aqueous alteration a zoned precursor reduction of precursor dust aggregate or recondensation of volatiles lost during chondrule formation the first four possibilities seem unlikely explanations for the zoning of the mesostasis but both reduction of precursor dust aggregate and recondensation of volatiles seem to have played significant roles to the formation of the zoning reducing conditions at high temperatures are suggested to have prevailed during the formation of group a1 chondrules

constraints on explosive sources with spall from near source waveforms spall the tensile failure of a material due to high stress loading has been observed in a number of contained and surface explosions the phenomenon results in a repartition of the initial spherical explosion energy source yielding a second energy source which is cylindrical and delayed in time recent spall models by day et al 1983 demanding conservation of momentum have shown the phenomenon to have little contribution to 20 sec surface waves these models are extended to include the effect of the process on near source seismograms the spall model is constrained by observations within the nonlinear regime of the source which bound the mass momentum and timing of the process comparison of these forward models with the inverse vertical point force source inferred from seismic recordings of a bermed surface explosion yields excellent agreement the spall model developed from the contained explosion cheat is used to create synthetic seismograms comparisons of these waveforms with those from a mueller murphy contained explosion indicate that the waveform contribution from spall is similar in size to the spherical explosion waveform the complete synthetic composed of the spall and explosion contribution compares favorably with observational data from the cheat experiment in both amplitude and energy distribution

widespread solid particle formation by mountain waves in the arctic stratosphere observations of polar stratospheric clouds pscs by lidar show that the clouds often contain solid particles which are most likely composed of nitric acid hydrates however laboratory experiments indicate that such hydrate particles are not easily formed under arctic synoptic scale conditions suggesting that solid psc particles should be rather rare here we show results from a model study indicating that mountain induced mesoscale temperature perturbations may be an important source of nitric acid hydrate particles in the arctic multiple arctic vortex trajectories were combined with a global mountain wave forecast model to calculate the potential for solid particle formation during december and january 1994 1995 the mountain wave model was used to calculate adiabatic cooling over several thousand ridge elements nitric acid hydrate particles were assumed to form in the mountain waves according to several microphysical mechanisms and were then advected using polar vortex filling synoptic trajectories to generate maps of solid particle occurrence the calculations show that mountain waves may be a significant source of pscs containing solid particles that are observed on the synoptic scale in particular the east coast of greenland the norwegian mountains and the urals are found to be solid particle sources with the pscs often predicted to survive several thousand kilometers downstream

seismicity of the rocky mountains and rio grande rift from the earthscope transportable array and crest temporary seismic networks 2008 2010 we developed a catalog of small magnitude ml 0 1 to 4 7 seismicity across colorado and new mexico from the earthscope usarray transportable array and crest colorado rocky mountains experiment and seismic transects seismic networks from 2008 to 2010 to characterize active deformation in the rio grande rift we recorded over 900 earthquakes in the rio grande rift region not including induced earthquakes and mine blasts and find that the rift is actively deforming both broadly and in distinct regions seismic events that are likely induced mostly in the raton basin make up 66 of the catalog 1837 earthquakes neogene faults in the northern rift in north central colorado are seismically active in the north park basin and northwestern colorado the central rift from the san luis basin southern colorado to south of the socorro magma body is the most seismically active rift region and seismicity delineates the deformation in the colorado plateau transition zone which is spatially correlated with volcanic vents dikes and faults within the western jemez lineament the eastern jemez lineament is nearly aseismic and surrounded by a halo of seismicity culminating in boundaries defined by recent moderate mw 3 9 and mw 3 3 earthquakes the southern rift is characterized by diffuse seismicity in texas and mexico this study provides an updated seismic catalog built with uniformity in seismometer coverage and low epicentral uncertainties 2 km that allows for regional evaluation of seismicity during this time period clusters of seismicity and moderate magnitude earthquakes characterize deformation in a low strain rate extensional environment

spectra of quarry blasts and microearthquakes recorded at local distances in israel in northern israel quarry blasts and microearthquakes occur in a region with complicated tectonics therefore correct event identification preferably based on a simple method that can be applied on a routine basis is essential for accurate and detailed seismotectonic studies spectral analysis of quarry blasts and microearthquakes recorded at local distances 5 2000 km by stations of the israel seismograph network revealed spectral characteristics in the frequency range less than 12 5 hz that can be used routinely for event identification most quarry blasts in northern israel are ripple fired open pit blasts consequently we chose an event discrimination method based on the recognition of ripple firing patterns in the signal a simple model for ripple firing parameters based on interference theory of linear systems and including random effects predicts spectral minima at low frequencies identical for different seismic phases we compared the spectra of complete seismogram signals of 52 events recorded by the isn at different distances and azimuths including both microearthquakes and quarry blasts in a selected region of northern israel consistent spectral modulation was found in a band from about 2 to 8 hz for 18 of 21 reliably identified i e reported quarry blasts with time delays of 20 to 40 msec the spectral minima frequencies correspond to those predicted by the theory

chemical and physical studies of type 3 chondrites iii chondrules from the dhajala h3 8 chondrite abstract fifty eight chondrules were separated from the dhajala h3 8 chondrite and their thermoluminescence properties were measured chips from 30 of the chondrules were examined petrographically and with electron microprobe techniques the bulk compositions of 30 chondrules were determined by the fused bead technique porphyritic chondrules especially 5 which have particularly high contents of mesostasis tend to have higher tl mass normalized than non porphyritic chondrules significant correlations between log tl and the bulk cao al 2 o 3 and mno content of the chondrules and between log tl and the cao al 2 o 3 sio 2 and normative anorthite content of the chondrule glass indicate an association between tl and the abundance and composition of mesostasis unequilibrated chondrules i e those whose olivine is compositionally heterogeneous and high in ca have low tl whereas equilibrated chondrules have a wide range of tl depending on their chemical and petrographic properties we suggest that the tl level in a given chondrule is governed by its bulk composition which largely determined the abundance and composition of constituent glass and by metamorphism which devitrfied the glass in those chondrules with high ca glass to produce the tl phosphor we also suggest that one reason why certain chondrules in type 3 ordinary chondrites are unequilibrated while others are equilibrated is that the mesostasis of the unequilibrated chondrules resisted the devitrification this devitrification is necessary for the diffusive communication between chondrule grains and matrix that enables equilibration

azimuthal variation of short period rayleigh waves from cast blasts in northern arizona we have examined the generation and propagation of short period sp rayleigh waves rg from two cast blasts of similar yield 726 000 kg of explosives delay sequence and near source geology at a coal mine in northern arizona the blasts were oriented approximately perpendicular to each other allowing for radiation pattern studies at regional distances near source seismic p and lg phases the observation of these rg radiation patterns at regional distances could act as a cast blast discriminant in regions of monitoring concern

high frequency seismic observations and models of chemical explosions implications for the discrimination of ripple fired mining blasts discrimination of large chemical explosions e g mining blasts from possible clandestine nuclear tests e g decoupled explosions is a significant issue for seismic verification unless discrimination is possible the numerous mining blasts within the ussr would give ample opportunity for concealing a clandestine test evernden et al 1986 advocate high frequencies as a means to detect these clandestine tests however mining blasts must still give a unique signature for their discrimination specific conditions are also necessary for high frequency verification low attenuation and quiet seismic stations are among the most important in this study we address these problems under conditions representing a best case scenerio during the summer of 1985 lawrence livermore national laboratory llnl deployed a regional array and high frequency seismic station near rson red lake ontario canada to study regional seismic signals at a low noise site with excellent propagation characteristics the continental shield one objective was to evaluate the performance of regional seismic arrays and high frequency stations in this geological environment using high frequency data from mining blasts within the mesabi iron range in northern minnesota distance of 380 km we also observed the high frequency pn phase of ripple fired blasts modeled their source properties and evaluated a possible discriminant for chemical explosions this study suggests the existence of a distinctive signature for large chemical explosions strong high frequency spectral peaks in the p spectra introduced by delay shooting or ripple firing its application depends however on a frequency band extending to at least 35 hz at regional distances reasonably uniform delay times in the blast pattern predictably quiet seismic sites and minimal path attenuation for high frequencies at 380 km we observe good propagation to 30 hz at 50 hz the evidence suggests severe attenuation or scattering which is consistent with a total q between 1500 and 2500 attenuation estimates assuming a simple source behavior e g f 2 or f 3 at high frequencies for mining explosions would give incorrect values of q unless corrected for the blast pattern these attenuations will limit the value of high frequencies for the detection of small decoupled explosions at regional distances

detection and analysis of near surface explosions on the kola peninsula seismic and infrasonic observations of signals from a sequence of near surface explosions at a site on the kola peninsula have been analyzed norsar s automatic network processing of these events shows a significant scatter in the location estimates and to improve the automatic classification of the events we have performed full waveform cross correlation on the data set although the signals from the different events share many characteristics the waveforms do not exhibit a ripple for ripple correspondence and cross correlation does not result in the classic delta function indicative of repeating signals using recordings from the arces seismic array 250 km w of the events we find that a correlation detector on a single channel or three component station would not be able to detect subsequent events from this source without an unacceptable false alarm rate however performing the correlation on each channel of the full arces array and stacking the resulting traces generates a correlation detection statistic with a suppressed background level which is exceeded by many times its standard deviation on only very few occasions performing f k analysis on the individual correlation coefficient traces and rejecting detections indicating a non zero slowness vector results in a detection list with essentially no false alarms applying the algorithm to 8 years of continuous arces data identified over 350 events which we confidently assign to this sequence the large event population provides additional confidence in relative travel time estimates and this together with the occurrence of many events between 2002 and 2004 when a temporary network was deployed in the region reduces the variability in location estimates the best seismic location estimate incorporating phase information for many hundreds of events is consistent with backazimuth measurements for infrasound arrivals at several stations at regional distances at lycksele 800 km sw of the events as well as at arces infrasound is detected for most of the events in the summer and for few in the winter at apatity some 230 km s of the estimated source location infrasound is detected for most events as a first step to providing a ground truth database for this useful source of infrasound we provide the times of explosions for over 50 events spanning 1 year

chemical and physical studies of type 3 chondrites 2 thermoluminescence of sixteen type 3 ordinary chondrites and relationships with oxygen isotopes thermoluminescence tl sensitivity values for sixteen type 3 ordinary chondrites fourteen of them from antarctica have been measured the values obtained normalized to the tl sensitivity of the dhajala meteorite range from 1 6 allan hills a77216 to 0 010 allan hills a77176 and include two reckling peak a80207 and allan hills a77176 that are particularly low they fill a hiatus in the tl distribution that previously existed between st mary s county and bishunpur the latter being a meteorite with one of the lowest tl sensitivities known the histogram of tl sensitivity values now shows a single distribution with higher values preferred it resembles the histogram for l chondrites occupying the petrologic types 3 4 5 and 6 there is a tendency for the tl sensitivity of meteorites to decrease as 18o increases equilibrated meteorites have tl sensitivities of 5 50 and 18o 4 5 to 5 0 while the most primitive meteorites with tl 0 01 have 18o 5 7 to 6 2 meteorites with intermediate tl have intermediate 18o theoretically it is possible that the range of 18o values observed may reflect progressive loss of o in the form of co at very low temperatures but very restrictive physical conditions and a complex history seem to be required

graphite magnetite aggregates in ordinary chondritic meteorites aggregates consisting largely of submicrometre graphite and magnetite crystals have been identified in 14 unequilibrated and regolith breccia ordinary chondrites like other primitive components they formed before the meteorites accreted chondrite clasts rich in graphite magnetite occur in three regolith breccias and are a new kind of unequilibrated ordinary chondrite they were probably the source of graphite magnetite aggregates in regolith breccias

the thermoluminescence sensitivity metamorphism relationship in ordinary chondrites experimental data on the mechanism and implications for terrestrial systems hydrothermal annealing experiments have been performed on samples of the sharps meteorite in order to investigate the mechanism responsible for the metamorphism related 105 fold range in the thermoluminescence tl sensitivity in ordinary chondrites duplicate 50 mg samples of meteorite were annealed under the following conditions a 168 h at 785 c and 1 kbar b the same time temperature and pressure but with 2 wt water c 174 h at 855 c and 0 77 kbar with 2 wt water and 2 molal sodium disilicate nadisi d the same time temperature and pressure as the preceding samples but with 10 wt h2o and 2 molal nadisi samples annealed under the first three sets of conditions showed little or no change in their tl sensitivities however the samples annealed with 10 wt water and 2 molal nadisi showed a 3 to 10 fold increase in tl sensitivity and the temperature of the tl peak was suggestive of feldspar in the high temperature form we suggest that these data are consistent with the tl sensitivity metamorphism relationship in ordinary chondrites being due to the formation of the tl phosphor feldspar by the crystallization of chondrule glass

ground motions underground compared to those on the surface a case study from sudbury ontario we compare signals recorded on hard rock seismographic stations in sudbury ontario to those recorded in caverns below the surface stations in the sudbury neutrino observatory signals from shallow local events show strong apparent amplification of ground motion observed on the surface relative to those recorded at depths of 1 4 2 1 km the amplification peaks near 2 1 hz where it is on average a factor of 3 to 5 the peak narrows decreases in amplitude and shifts toward lower frequencies 0 8 1 hz for regional and teleseismic events the peak in apparent amplification for the local events is attributed to a strong rg phase from shallow events at close distances the frequency shift and decay of the amplitude of this peak for more distant events reflects the rapidly diminishing influence of the higher frequency components of this phase with distance coupled with the increasing importance of shear wave phases

antarctic nat psc belt of june 2003 observational validation of the mountain wave seeding hypothesis abstract satellite observations of polar stratospheric clouds pscs over antarctica in june 2003 revealed small nitric acid trihydrate nat particles forming suddenly along the vortex edge models suggest the trigger was mountain waves over the antarctic peninsula ap forming ice for nat nucleation we test this hypothesis by analyzing perturbations in stratospheric radiances from the atmospheric infrared sounder airs airs data show mountain waves over the ap on 10 14 june with no resolved wave activity before or after peak wave temperature amplitudes derived from independent 40 hpa channels all return values of 10 12 k in agreement with values used to model this nat event these observations support a nat wake from a small region of mountain wave activity over the ap as the source of this circumpolar nat outbreak

quasi lagrangian superpressure balloon measurements of gravity wave momentum fluxes in the polar stratosphere of both hemispheres 1 superpressure balloons were flown in 2002 and 2005 in the winter polar vortices of both hemispheres the balloons can drift for months in the stratosphere acting as quasi lagrangian tracers of air parcel motions the meteorological datasets acquired are used to retrieve small scale internal atmospheric gravity wave parameters using wavelet techniques for the first time gravity wave momentum fluxes are estimated over wide geographical areas and the results will help constrain gravity wave parameterization schemes used in general circulation climate models the importance of mountain waves is confirmed with largest fluxes observed in the lee of greenland and the antarctic peninsula however significant momentum fluxes are also observed over the oceans showing the importance of other wave generation mechanisms

observations and simulations of a large amplitude mountain wave breaking over the antarctic peninsula 1 a case study of a large amplitude orographic gravity wave occurring over the antarctic peninsula is presented based on observations from the vorcore balloon campaign and on mesoscale numerical simulations the vorcore campaign september 2005 to february 2006 consisted in the flight of 27 superpressure balloons in the core of the southern hemisphere stratospheric polar vortex at altitudes of 16 19 km from september 2005 to february 2006 on 7 october 2005 one of the balloons exploded as it was flying above the antarctic peninsula the observations collected by another balloon that was flying during the same time period above the peninsula suggest the presence of a very intense gravity wave peak to peak amplitude of the order of 25 30 m s 1 in zonal and meridional velocity disturbances the wave packet is likely undersampled in the balloon observations because of its high intrinsic frequency but the balloon data set is complemented with high resolution numerical simulations carried out with the weather research and forecast model the simulations are validated by comparison with the balloon measurements and show that the wave was breaking in the lower stratosphere at the time and height where the balloon exploded the simulations highlight several consequences of the mountain wave on the stratosphere forcing of the mean flow generation of secondary inertia gravity waves and turbulence and mixing in particular the momentum fluxes are calculated and are found to compare well with the estimates from balloon measurements the large values found are likely extreme values which raises the issue of their representativity to discuss this the balloon measurements are used in conjunction with operational analyses to estimate the frequency of such large amplitude gravity waves i e to provide an estimate of their intermittency

chemical and physical studies of type 3 chondrites iv annealing studies of a type 3 4 ordinary chondrite and the metamorphic history of meteorites abstract samples of a type 3 4 chondrite have been annealed at 400 1000 c for 1 200 hours their thermoluminescence properties determined and analyzed for k na mn sc and ca by instrumental neutron activation analysis after annealing at 900 c the samples showed a 50 decrease in tl sensitivity while after annealing at 1000 c it fell to 0 1 0 01 times its unannealed value and loss of na and k occurred the tl and compositional changes resemble those observed for the equilibrated kernouve chondrite after similar annealing treatments except that the sharp tl decrease and element loss occurred at 1100 c this difference is presumably due to petrographic differences in the feldspar of the two meteorites the temperature and the width of the tl peak showed a discontinuous increase after annealing at 800 c peak temperature jumped from 130 to 200 c and peak width increased from 90 to 150 c the activation energies for these tl changes are 7 10 kcal mole similar increases in the tl peak temperature have been reported in tl studies of amelia va albite where they were associated with the low to high temperature transformation however the activation energy for the transformation is 80 kcal mole these changes in tl emission characteristics resemble trends observed in type 3 ordinary chondrites and it is suggested that type 3 3 3 5 chondrites have a low feldspar as tl phosphor and 3 5 have high feldspar as the phosphor thermoluminescence therefore provides a means of palaeothermometry for type 3 ordinary chondrites

considerations in phase estimation and event location using small aperture regional seismic arrays the global monitoring of earthquakes and explosions at decreasing magnitudes necessitates the fully automatic detection location and classification of an ever increasing number of seismic events many seismic stations of the international monitoring system are small aperture arrays designed to optimize the detection and measurement of regional phases collaboration with operators of mines within regional distances of the arces array together with waveform correlation techniques has provided an unparalleled opportunity to assess the ability of a small aperture array to provide robust and accurate direction and slowness estimates for phase arrivals resulting from well constrained events at sites of repeating seismicity a significant reason for the inaccuracy of current fully automatic event location estimates is the use of f k slowness estimates measured in variable frequency bands the variability of slowness and azimuth measurements for a given phase from a given source region is reduced by the application of almost any constant frequency band however the frequency band resulting in the most stable estimates varies greatly from site to site situations are observed in which regional p arrivals from two sites far closer than the theoretical resolution of the array result in highly distinct populations in slowness space this means that the f k estimates even at relatively low frequencies can be sensitive to source and path specific characteristics of the wavefield and should be treated with caution when inferring a geographical backazimuth under the assumption of a planar wavefront arriving along the great circle path moreover different frequency bands are associated with different biases meaning that slowness and azimuth station corrections commonly denoted sascs cannot be calibrated and should not be used without reference to the frequency band employed we demonstrate an example where fully automatic locations based on a source region specific fixed parameter template are more stable than the corresponding analyst reviewed estimates the reason is that the analyst selects a frequency band and analysis window which appears optimal for each event in this case the frequency band which produces the most consistent direction estimates has neither the best snr or the greatest beam gain and is therefore unlikely to be chosen by an analyst without calibration data

regional and teleseismic analysis of underground nuclear explosion waveforms and constraints for shear wave excitation mechanisms 1 regional and teleseismic waveforms of underground nuclear explosions unes at the balapan and the nevada test sites are analyzed to understand the nature of shear waves excited from unes the phase composition of wavefields in the source and receiver regions is examined using a source array frequency wave number analysis and polarization analyses it is observed that regional mantle lid shear waves sn often develop strongly on the other hand observed teleseismic shear waves from unes are much weaker than those from earthquakes source array analyses of the shear waves from unes display coherent energy that is polarized in a certain azimuthal direction the observation of coherent shear energy in different unes suggests that the shear energy is excited in a consistent manner at every une we constrain the dominant shear wave excitation mechanism from the observed shear wave features the observations appear to be consistent with the tectonic release model with conical rock cracking

moment tensor analysis of very shallow sources an issue for moment tensor mt inversion of shallow seismic sources is that some components of the green s functions have vanishing amplitudes at the free surface which can result in bias in the mt solution the effects of the free surface on the stability of the mt method become important as we continue to investigate and improve the capabilities of regional full mt inversion for source type identification and discrimination it is important to understand free surface effects on discriminating shallow explosive sources for nuclear monitoring purposes it may also be important in natural systems that have very shallow seismicity such as volcanic and geothermal systems we examine the effects of the free surface on the mt via synthetic testing and apply the mt based discrimination method to three quarry blasts from the humming albatross experiment these shallow chemical explosions at 10 m depth and recorded up to several kilometers distance represent rather severe source station geometry in terms of free surface effects we show that the method is capable of recovering a predominantly explosive source mechanism and the combined waveform and first motion method enables the unique discrimination of these events recovering the design yield using seismic moment estimates from mt inversion remains challenging but we can begin to put error bounds on our moment estimates using the network sensitivity solution technique ford et al 2010 online material figures showing synthetic tests for a pure explosion and a composite source at local distances and table of moment tensor components

seismic source mechanisms for quarry blasts modelling observed rayleigh and love wave radiation patterns from a texas quarry summary a theoretical understanding of the mechanisms by which quarry blasts excite seismic waves is useful in understanding how quarry blast discriminants may be transported from one region to another an experiment in texas with well placed seismic stations and a cooperative blasting engineer has shed light on some of the physical mechanisms of seismic excitation at short periods 0 1 3 hz azimuthal radiation patterns of the 0 2 3 hz rayleigh and love waves are diagnostic of two proposed mechanisms for non isotropic radiation from quarry blasts observations show that the love and rayleigh wave radiation patterns depend upon the orientation of the quarry benches two possible mechanisms for non isotropic radiation are 1 the lateral throw of spalled material and 2 the presence of the topographic bench in the quarry the spall of material can be modelled by vertical and horizontal forces applied to the free surface with time functions proportional to the derivative of the momentum of the spalled material we use wavenumber integration synthetics to model the explosion plus spall represented by seismic moment tensor sources plus point forces the resulting synthetics demonstrate that the magnitude of the sh love compared with the sv fundamental rayleigh or rg in the short period band 0 5 3 hz may be explained by the spall mechanism nearly all of the available mass must participate in the spall with an average velocity of 2 5 m s 1 to provide sufficient impulse to generate the observed love waves love wave radiation patterns from such a mechanism are consistent with the spall mechanism we modelled the effects of the topographic bench using 3 d linear finite difference calculations to compute progressive elastic wavefields from explosion sources behind the quarry bench these 3 d calculations show sh radiation patterns consistent with observations while the sv radiation patterns are not consistent with observations we find that the radiation patterns from the explosion behind the 3 d bench cannot be modelled by a modified moment tensor the 3 d effects of the bench are more complicated than the representation by a moment tensor with a single reduced horizontal couple the 3 d finite difference synthetics exhibit strong azimuthal asymmetry and polarity reversals in the outgoing p sv waves p s and rg radiated behind the bench for v p v s ratios between 2 and 3 both mechanisms may contribute to the non isotropic radiation patterns but the spall mechanism is the simplest physical mechanism that explains the bulk of the observations adjustments to the time functions for the horizontal force the vertical force and the explosion source may further refine the remaining differences between prediction and the observations

quantification and characterization of regional seismic signals from cast blasting in mines a linear elastic model summary cast blasts in coal mines designed to move large volumes of overburden are a source of large 1 5 kt frequent explosions in parts of the world with near surface coal resources mining events of this source type are triggering the prototype international monitoring system for the comprehensive test ban treaty being tested under the group of scientific experts technical test 3 gsett 3 we wish to develop techniques to distinguish between the seismic signals produced by these explosions and equivalent size single or point sources to that end we have developed a linear elastic model to simulate regional distance seismograms from mining cast blasts cast blasting involves a shot array with delayed detonations casting rock horizontally into a pit we model the effects of the millisecond delay firing pattern the depth of the pit and the cast of material into the pit we attempt to separate the effects due to the explosion the vertical movement of mass and the horizontal movement of mass in order to produce a physical understanding of the resulting waveforms which can be used to assess potential discriminants for these types of explosions these physical models of source processes are constrained by near surface measurements of cast blasts in ne wyoming that are triggering gsett 3 two observational results at regional distances that are replicated by these models are the excitation of 8 12s surface waves by the cast blasts and the insensitivity of peak amplitude to total explosive size for normal blasting practices the insensitivity of peak amplitudes from the cast blast to total source size is a consequence of the delay firing practice under normal procedures this practice was initiated to reduce ground motions in the near source region around the mine and it appears that it is also successful in controlling peak amplitudes at regional distances the mass transfer into the pit has both a vertical and a horizontal force component each of which contribute to the final seismogram the latter being azimuthally dependent assuming maximum coupling the contribution to the seismogram due to the vertical force component is approximately equal to the explosion contribution for pit depths of about 10 m but dominates for pit depths of 20 m or greater the contribution due to the horizontal force component is mainly in the enhanced rayleigh waves comparison of high frequency seismic radiation from the single shot and cast blast shows little qualitative difference in the regional waveforms

source scaling of contained chemical explosions as constrained by regional seismograms quantification of source coupling and characterization parameters for contained single fired chemical explosions observed at a regional seismic array are quantified the explosions were conducted in a mine in northeast wyoming where delay fired explosions occur regularly the primary observational data sets consist of close in measurements in the mine and regional observations at the international monitoring system primary array at pinedale wyoming pdar the single fired explosions ranged in size from 5500 to 50 000 lb and were separated from one another from 30 m to over 4 km peak amplitude measures at a single element of the regional array are well matched with a power law dependence on explosive weight similar scaling constants were determined for each of the dominant regional phases p n 0 84 0 14 p g 0 84 0 09 and l g 0 91 0 08 peak amplitudes across pdar show a factor of 3 variation for an individual explosion across all array elements this amplitude variation is accompanied by a decrease in spatial correlation with increasing station separation indicating the importance of near receiver structure the regional signals were further characterized by computing frequency dependent envelope functions at each array element consistent source scaling factors at a single array element were obtained from the envelope functions a high degree of spatial variability as a function of frequency was documented for the envelope functions spectral ratios are used to investigate source scaling relations for the different explosions four similarly prepared shots with total explosive weights between 5500 and 6000 lb were detonated to investigate source repeatability spectral ratio analysis identified two of the four shots as only partially detonating resulting in a reduction of long period spectral level by factors of 10 and 50 these long period reductions were accompanied by increases in source corner frequency consistent with a smaller source size spectral ratios of waveforms from the larger explosions that fully detonated illustrate that p g and l g source functions are similar the empirical source ratio is well modeled with a mueller murphy source model these experiments and the resulting data analysis suggest that simple single fired explosions of modest explosive weight can be used to calibrate regional seismic arrays networks and individual stations

evidence for inertia gravity waves forming polar stratospheric clouds over scandinavia 1 at three successive days at the end of january 2000 the deutsches zentrum fur luft und raumfahrt dlr airborne lidar ozone lidar experiment explored mountain wave induced polar stratospheric clouds above the scandinavian mountain ridge global analyses and mesoscale modeling are applied to explain their complex internal structure and their day to day variability depending on the synoptical scale meteorological conditions stratospheric temperature anomalies of different amplitude and horizontal extent are generated by the upward propagating mountain waves short term excitation of about 6 hours resulted in localized stratospheric temperature anomalies directly above the mountain ridge as for 25 january 2000 in this case the elevation of the observed clouds differed not much from the synoptic scale clouds upstream above the norwegian sea on the other hand long lasting flow past the scandinavian mountain ridge formed huge 400 km horizontally extending stratospheric ice clouds in altitudes as much as 5 km above the elevation of the upstream clouds just 1 day later inertia gravity waves with horizontal wavelengths of about 350 km are responsible for their formation for the first time a predicted temperature minimum far downstream of the mountains could be proofed by the observation of an isolated stratospheric ice cloud above finland the observed particles are classified in terms of their measured optical properties such as backscatter ratio and depolarization in all cases mountain waves generated ice clouds in contrast to the nitric acid trihydrate tail of the ice cloud on 25 january the same classification results in a tail of liquid supercooled ternary solutions droplets 1 day later the particle structure downstream of the mountains is very complex and needs detailed microphyical modeling and interpretation

thermoluminescence and the shock and reheating history of meteorites iv the induced tl properties of type 4 6 ordinary chondrites abstract the induced thermoluminescence tl properties of 121 equilibrated ordinary chondrites have been measured the samples were 74 h and 47 l chondrites of which 33 h and 32 l were from antarctica the distribution of tl sensitivities for non antarctic l chondrites differs from that of non antarctic h chondrites consistent with a greater proportion of the former class suffering post metamorphic shock data on the effect of laboratory annealing on tl sensitivity and step wise ar release measurements enable the meteorites to be sorted into three shock related temperature groups

spectral discrimination between quarry blasts and earthquakes in southern california we compare p wave spectra of quarry blasts and earthquakes recorded by the southern california seismic network scsn between 2000 and 2005 with the goal of developing methods to discriminate between these events we process the spectra using an iterative robust least squares method to isolate source receiver and propagation path contributions this corrects for first order attenuation structure as well as near receiver site effects and any errors in the instrument response functions using the earthquake spectra and a simple omega 2 source model we compute an empirical green s function egf to remove the trade off between the source terms and other parameters in our model a constant stress drop model gives a good fit to the observed average earthquake spectra over a wide range of moment magnitude but provides a mediocre fit to the average quarry blast spectra which have a generally steeper fall off at high frequencies than omega 2 we also compare p and s wave amplitudes and find modestly smaller average s amplitudes for the explosions compared to the earthquakes for southern california the root mean square rms misfit of p wave spectra to an omega 2 source model is a more reliable explosion discriminant than the s to p amplitude ratio and works for about 90 of the events

thermoluminescence and the shock and reheating history of meteorites iii the shergottites abstract the thermoluminescence tl sensitivities of the four shergottites are extremely low and display a 10 fold range values are 0 15 to 1 8 where dhajala 1000 with the tl sensitivity decreasing with increasing peak temperature from about 140 to 180 c and peak width from about 100 to 150 c a mineral separation experiment indicates that the mineral producing the tl is associated with the maskelynite presumably nanogram per gram quantities of crystalline feldspar are present in the maskelynite samples of shergotty allan hills a77005 and elephant moraine a79001 were annealed at 400 900 c for 24 98 h for shergotty the peak increased in width and moved to higher temperatures in the glow curve while for allan hills a77005 and elephant moraine a79001 whose tl peaks were already broad and at high temperatures remained unchanged all samples showed a significant increase in tl sensitivity when annealed at 600 700 c apparently the feldspar is present in varying proportions of high to low temperature form and in amounts which vary from meteorite to meteorite we conclude that the shergottites underwent post shock recrystallization at a variety of cooling rates and that the order of increasing cooling rate was shergotty allan hills a77005 zagami and elephant moraine a79001 the presence of a high temperature phase implies peak post shock cooling temperatures 600 c and that the size of the ejecta was

chemical and physical studies of chondrites x cathodoluminescence and phase composition studies of metamorphism and nebular processes in chondrules of type 3 ordinary chondrites abstract the cathodoluminescence cl properties of eight type 3 ordinary chondrites and one l5 chondrite have been determined and phenocryst and mesostasis compositions have been analyzed in the chondrules of four of them semarkona type 3 0 krymka 3 1 allan hills a77214 3 5 and dhajala 3 8 in order to investigate their origins and metamorphic history two major classes of chondrule with eight subdivisions have been identified mainly on the basis of cl properties and 95 of the chondrules can be assigned to these groups on the basis of phenocryst and mesostasis composition class a chondrules consisting of those with plagioclase normative mesostasis with bright cl are subdivided into groups a1 a2 a3 a4 and a5 class b chondrules with little or no cl and having quartz normative mesostases in the least metamorphosed chondrites which becomes feldspathic with metamorphism are subdivided into groups b1 b2 and b3 relationships between the eight chondrule groups can be deduced from their relative abundance in each of the nine chondrites groups a1 a2 b1 and a5 are present in semarkona 15 20 60 5 by number respectively group a5 chondrules in semarkona being more heterogeneous than a5 chondrules in chondrites of higher petrologic type chondrule group a1 evolves into a3 then a4 and then a5 during metamorphism while a2 evolves into a4 and then a5 chondrule group b1 evolves into b2 b3 and then a5 but higher levels of metamorphism are required to complete the series than for the a1 5 series conversion of a group to an adjacent group can be observed in allan hills a77214 3 5 where several chondrules are group b3 in their central regions and group a5 in their outer regions the present chondrule groups are essentially independent of texture since group a and group b chondrules differ in bulk composition redox state and possibly oxygen isotope systematics their relative abundance might be a factor in the creation of the nine chondrite classes

observation and analysis of a large amplitude mountain wave event over the antarctic peninsula 1 we use measurements from the atmospheric infrared sounder airs on the aqua satellite to observe the 3 dimensional structure of a gravity wave event over the antarctic peninsula and determine the horizontal and vertical wavelengths propagation direction and temperature amplitude and from these we estimate wave momentum flux using theoretical knowledge of the weighting functions and radiative transfer for airs radiance measurements at temperature sensitive channels in the infrared we derive a method of estimating wave temperature amplitude directly from the radiance measurements comparison of the radiance based temperature amplitudes to the temperature amplitude in airs retrieved temperature fields shows close agreement because the radiances have 3 times better horizontal resolution than the retrievals our analysis suggests we can routinely observe important geophysical properties of waves with horizontal wavelengths as short as 80 km using airs radiances we further analyze a nearly identical wave event appearing in the european centre for medium range forecasts ecmwf temperature and wind fields from both assimilation and forecast data analysis of the ecmwf data and nearby radiosonde wind profiles allows the interpretation as a mountain wave event forced by flow over the topography of the antarctic peninsula

characteristics of rg waves recorded from quarry blasts in central texas abstract chemical blasts from quarrying operations in central texas are routinely recorded by the w m keck foundation seismological observatory near china spring texas the keck observatory consists of a single broadband three component borehole seismograph system five quarries located at distances ranging from 16 to 101 km from the observatory each detonate from 1 to 6 tons of ammonium nitrate fuel oil explosive on the average of twice per week for every quarry for which the orientation of the working face could be determined dispersed rg waves are recorded at the keck observatory from those quarries at which the working face is directed away from the observatory but are not observed or are severely attenuated from those quarries at which the working face is directed toward the observatory seismograms containing the dispersed rg are easily recognized as quarry blasts but those in which the dispersed rg is absent look like small earthquakes

thermoluminescence and the origin of the dark matrix of fayetteville and similar meteorites abstract the induced thermoluminescence properties and carbon contents of the dark matrix and light clasts of 6 regolith breccias have been measured the tl sensitivity of the matrix normalized to that of the clasts decreases from 0 8 to 0 3 with increasing inert gas content increasing abundances of highly volatile elements and carbon and decreasing amounts of interstitial grain boundary glass for meteorites with the highest inert gas contents fayetteville and leighton the matrix samples have broader tl peaks by 10 c and lower peak temperatures by 10 c than the light clasts whereas meteorites with low inert gas contents e g pantar do not show this difference in the tl properties of the two lithologies it is argued that the data are consistent with the formation of the dark matrix by comminution of the light clasts with the addition of a component perhaps cm like chondrites with tl properties distinct from those of ordinary chondrites the present data are inconsistent with the matrix being a new primitive material akin to type 3 ordinary chondrites or with the dark matrix being related to the clasts by purely thermal processes

a thermoluminescence study of experimentally shock loaded oligoclase and bytownite the thermoluminescence tl of samples of terrestrial oligoclase and bytownite shock loaded to 10 5 45 gpa have been measured the tl sensitivities of both feldspars decreased 10 fold after shock loading to 25 32 gpa and for the oligoclase 25 fold after shock loading to greater pressures the shock induced changes for oligoclase are very similar to those of the kernouve meteorite in which the tl phosphor is oligoclase after similar shock loading the data indicate that ordinary chondrites of shock facies d f have suffered shock pressures over 25 gpa consistent with petrographic estimates petrographic studies on the shocked samples suggest that the lowering of tl sensitivity is caused by maskelynization and at the highest pressures melting the oligoclase samples shocked above 34 gpa showed changes in their glow curve shapes similar to those produced by annealing amelia albite and a type 3 4 ordinary chondrite above 700 c the dominant peak moves from 132 8 c to 230 12 c changes in the glow carve shape for bytownite resembled those produced by annealing certain shergottites in addition to a major peak at 138 3 c a peak appeared at 178 8 c for albite the changes were shown to be associated with small degrees of disordering and we suggest that shock induced disordering or some process closely associated with the onset of disordering is occurring in the trace amounts of feldspar that survive maskelynization after shock loading to pressures 34 gpa