geometry and physical properties of the socorro new mexico magma bodies analysis of multichannel seismic reflection profiles gathered by the consortium for continental reflection profiling cocorp constrains the geometry and material properties of a proposed magma body located within the rio grande rift a new spectral ratio method is used to find the reflectivities of the proposed midcrustal intrusion large and spatially variable reflectivities support the interpretation of the reflector as an intrusive molten magma complex modeling of the reflectivity suggests that in one location the intrusion took the form of several thin 30 to 40 m thick layers seismic wave attenuation within the rift s midcrust is low

incorporating socorro magma body reflections into the earthquake location process when network station spacing is large relative to event depths constraining focal depths using direct arrivals is difficult to help overcome this problem we incorporated the szs szp and pzp socorro magma body reflections into the earthquake location process to find a velocity model appropriate for combining direct and reflected arrivals we jointly inverted for 75 hypocenters and a one dimensional velocity model we used over 1000 direct arrivals and over 400 reflected arrivals solving for p velocity vp and poisson s ratio v above the approximate base of the seismogenic zone vp and v below the base of the seismogenic zone depth to the upper surface of the magma body and station corrections high velocity and low velocity initial models converged to the same solutions without damping we found that vp and v may both decrease slightly below about 10 km depth magma body depth is near 18 75 km a close fit between observed and modeled reflected phase arrival times and an even lateral distribution of positive and negative reflected phase residuals indicate that the magma body upper surface is nearly flat in the socorro area combining direct and reflected phases reduces average focal depth error by more than a factor of 3 and average origin time error by a factor of 2 compared with using only direct phases this is because reflected arrivals are more sensitive to changes in focal depth than direct arrivals and combining upgoing direct and downgoing reflected times reduces the trade off between focal depth and origin time for this method to be successful phases must be carefully identified to help identify secondary phases we used relative arrival time curves plotting phase minus p times versus s minus p times picking reflection pairs szp and szs szp and pzp or szs and pzp identified on a single seismogram significantly reduces the chances of phase misidentification the szp szs and szp pzp pairs also help prevent trade offs between reflector depth and focal depths

time stratigraphic framework for the eocene oligocene mogollon datil volcanic field southwest new mexico a time stratigraphic framework for discontinuously exposed regional ignimbrites in the eocene oligocene mogollon datil volcanic field has been established using correlations aided by 40ar 39ar age determinations and paleomagnetic analyses 40ar 39ar age spectra from sanidine separates 25 regional ignimbrites 85 samples 97 spectra yield well defined plateau ages that are precise within sample and within unit 1 0 5 and agree closely with independently established stratigraphic order paleomagnetic remanence directions 404 sites from individual ignimbrite outflow sheets are generally vertically and horizontally uniform throughout facies ranging from thick 100 500 m densely welded proximal ignimbrites to thin 1 5 30 m unwelded distal fringes between unit differences in paleomagnetic directions provide useful correlation criteria particularly for units having ages too close to be resolved using 40ar 39ar dating the mogollon datil time stratigraphic framework clarifies ignimbrite history and provides improved age control for intercalated lavas and sedimentary rocks ignimbrite activity was strongly episodic outflow sheets were primarily erupted in four discrete pulses representing synchronized activity of two separate cauldron complexes activity in the southern complex began at 36 2 ma near las cruces new mexico and subsequently migrated 220 km northwest culminating in the 28 0 ma bursum cauldron activity in the northern complex located west of socorro new mexico underwent a less defined and more modest 40 km westward migration over its 32 0 to 24 3 ma life span the four pulses of ignimbrite activity were 1 36 2 24 3 ma 12 major units 1 500 km3 total volume 2 32 0 31 4 ma three major units 1 500 km3 volume 3 29 1 27 4 ma nine major units 6 000 km3 and 4 24 3 ma one major unit the third and largest ignimbrite pulse was accompanied by extensive rhyolitic dome and flow eruptions in the area between the two main cauldron complexes

inferring aftershock sequence properties and tectonic structure using empirical signal detectors seismotectonic studies of the 2008 storfjorden aftershock sequence were limited to data acquired by the permanent but sparse regional seismic network in the svalbard archipelago storfjorden s remote location and harsh polar environment inhibited deployment of temporary seismometers that would have improved observations of sequence events the lack of good station coverage prevented the detection and computation of hypocenter locations of many low magnitude events mb 2 5 in the norsar analyst reviewed bulletin as a result the fine structure of the sequence s space time distribution was not captured in this study an autonomous event detection and clustering framework is employed to build a more complete catalog of storfjorden events using data from the spitsbergen spits array the new catalog allows the spatiotemporal distribution of seismicity within the fjord to be studied in greater detail information regarding the location of active event clusters provides a means of inferring the tectonic structure within the fault zone the distribution of active clusters and moment tensor solutions for the storfjorden sequence suggests there are at least two different structures within the fjord a ne sw trending linear feature with oblique normal to strike slip faulting and e w trending normal faults

using automated high precision repicking to improve delineation of microseismic structures at the soultz geothermal reservoir an automatic adaptive correlation based algorithm for adjusting phase picks in large digital seismic data sets provides significant improvement in resolution of microseismic structures using only a small fraction of the time and manpower which would be required to re analyze waveforms manually or semi automatically we apply this technique to induced seismicity at the soultz sous forets geothermal site france the method is first applied to a small previously manually repicked subset of the catalogue so that we may compare our results to those obtained from painstaking visual cross correlation based techniques relative centroid adjusted hypocenters show a decrease in median mislocation from 31 to 7 m for preliminary and automatically adjusted picks respectively compared to the manual results narrow intersecting joint features not observed in the preliminary hypocenter cloud but revealed through manual repicking are also recovered using the automatic method we then address a larger catalogue of 7000 microearthquakes after relocating the events using automatic repicks the percentage of events clustering within 5 m of their nearest neighbor increases form 5 to 26 of the catalogue hypocenter relocations delineate narrow linear features previously obscured within the seismic cloud interpreted as faults or fractures which may correspond to fluid propagation paths or to changes in stress as a result of elevated pore pressures rms travel time residuals for the larger data set are reduced by only 0 2 however phase pick biases in the preliminary catalogue have influenced both the velocity model and station correction calculations which will affect location residuals these pick biases are apparent on the adjusted stacked waveforms and correcting them will be important prior to future velocity model refinements

zonal and vertical structure of the madden julian oscillation abstract a statistical study of the three dimensional structure of the madden julian oscillation mjo is carried out by projecting dynamical fields from reanalysis and radiosonde data onto space time filtered outgoing longwave radiation olr data mjo convection is generally preceded by low level convergence and upward motion in the lower troposphere while subsidence cooling and drying prevail aloft this leads to moistening of the boundary layer and the development of shallow convection followed by a gradual and then more rapid lofting of moisture into the middle troposphere at the onset of deep convection after the passage of the heaviest rainfall a westerly wind burst region is accompanied by stratiform precipitation where lower tropospheric subsidence and drying coincide with continuing upper tropospheric upward motion the evolution of the heating field leads to a temperature structure that favors the growth of the mjo the analysis also reveals distinct differences in the vertical structure

a previously unreported type of seismic source in the firn layer of the east antarctic ice sheet we identify a unique type of seismic source in the uppermost part of the east antarctic ice sheet recorded by temporary broadband seismic arrays in east antarctica these sources termed firnquakes are characterized by dispersed surface wave trains with frequencies of 1 10 hz detectable at distances up to 1000 km events show strong dispersed rayleigh wave trains and an absence of observable body wave arrivals most events also show weaker love waves initial events were discovered by standard detection schemes additional events were then detected with a correlation scanner using the initial arrivals as templates we locate sources by determining the l2 misfit for a grid of potential source locations using rayleigh wave arrival times and polarization directions we then perform a multiple filter analysis to calculate the rayleigh wave group velocity dispersion and invert the group velocity for shear velocity structure the resulting velocity structure is used as an input model to calculate synthetic seismograms inverting the dispersion curves yields ice velocity structures consistent with a low velocity firn layer 100 m thick and show that velocity structure is laterally variable the absence of observable body wave phases and the relative amplitudes of rayleigh waves and noise constrain the source depth to be less than 20 m the presence of love waves for most events suggests the source is not isotropic we propose the events are linked to the formation of small crevasses in the firn and several events correlate with shallow crevasse fields mapped in satellite imagery

the nature of volcanic earthquake swarm preceding the 2000 flank eruption at usu volcano hokkaido japan summary the 2000 eruption of usu volcano hokkaido occurred on the northwestern flank of volcano on march 31 at 13 07 local time after about 4 days of intensive seismic activity we study the seismic process prior to the eruption using the routine earthquake catalogue of the japan meteorological agency jma and the digital seismograms of the short period station nbbt jma earthquakes began beneath the summit and southern slope of the volcano then seismic foci clustered along two linear zones intersecting to the south of the initial epicentral zone the majority of earthquakes occurred at depth within the range between 4 and 7 km the magnitude range of located earthquakes varied between 0 8 and 4 4 the earthquake epicentres did not reach the sites of the forthcoming eruption they stopped at a distance of about 1 3 km the eruption began during the ceasing of seismic activity a study of the nature of the swarm was performed for a sample of 303 earthquakes with a magnitude interval from 2 5 to 3 4 that were representative of the swarm visual analysis allowed separating the earthquakes into two groups 286 volcano tectonic vt earthquakes and 17 long period lp earthquakes the spectral analysis of s wave so f274 vt earthquakes in the frame of brune s model showed that the vt earthquakes may be separated into two groups as characterized by high stress drops hsd and low stress drops lsd the swarm began with hsd earthquakes the lsd and lp earthquakes were recorded about 30 40 hr later simultaneously with the beginning of deformation of volcanic edifice and accompanied the hsd earthquakes up to the beginning of eruption we attribute the hsd earthquakes to the probable product of magmatic thermal fracturing of host rocks the relatively long lsd ruptures may be attributed to the slips along the pre existing fractures during magma movement

improving local earthquake locations using the l1 norm and waveform cross correlation application to the whittier narrows california aftershock sequence experiments with different earthquake location methods applied to aftershocks of the october 1 1987 whittier narrows earthquake in california ml 5 9 suggest that local event locations can be greatly improved through the use of the l1 norm station corrections and waveform cross correlation the whittier narrows sequence is a compact cluster of over 500 events at 12 to 18 km depth located within the dense station coverage of the southern california seismic network scsn a telemetered network of several hundred short period seismographs scsn travel time picks and waveforms obtained through the southern california earthquake center are examined for 589 earthquakes between 1981 and 1994 in the vicinity of the mainshock using a smoothed version of the standard southern california velocity model and the existing travel time picks improved location accuracy is obtained through use of the l1 norm rather than the conventional least squares l2 norm approach presumably due to the more robust response of the former to outliers in the data a large additional improvement results from the use of station terms to account for three dimensional velocity structure outside of the event cluster to achieve greater location accuracy waveforms for these events are resampled and low pass filtered and the p and s wave cross correlation functions are computed at each station for every event pair for those events with similar waveforms differential times may be obtained from the cross correlation functions these times are then combined with the travel time picks to invert for an adjusted set of picks that are more consistent than the original picks and include seismograms that were originally unpicked locations obtained from the adjusted picks show a further improvement in accuracy location uncertainties are estimated using a bootstrap technique in which events are relocated many times for sets of picks in which the travel time residuals at the best fitting location are used to randomly perturb each pick improvements in location accuracy are indicated by the reduced scatter in the residuals smaller estimated location errors and the increased tendency of the locations to cluster along well defined fault planes median standard errors for the final inversion are 150 m in horizontal location and 230 m in vertical location although the relative locations within localized clusters of similar events are better constrained seismicity cross sections resolve the shallow dipping fault plane associated with the mainshock and a steeply dipping fault plane associated with a ml 5 3 aftershock these fault planes appear to cross and activity began on the secondary fault plane prior to the large aftershock

the significance of fractional crystallization in the petrogenesis of apollo 17 type a and b high ti basalts abstract whole rock and mineral analyses of 26 new type a and b apollo 17 basalts are reported the petrography and mineral chemistry of these basalts are similar to previously reported apollo 17 basalts however these new whole rock data extend the compositional ranges of previously reported type a and b basalts and require the division of the type b basalts into type b1 and b2 varieties these three types display similar trends when both major and trace elements are plotted against a fractionation index of cr la ratio major element compositions of basalts from all three types fall on olivine ti oxide control lines the compositional ranges of all three groups can be effectively generated by 40 50 fractional crystallization of observed phenocryst phases the compositions of three type a basalts are only generated after 80 fractional crystallization previous models of different degrees of partial melting and kreep assimilation were developed in order to explain the range in la sm ratio of the type b basalts with the recognition of two types of b basalts these models are no longer valid this study demonstrates that apollo 17 type a b1 and b2 basalts have a relatively simple petrogenesis with the only post magma generation process being fractional crystallization

the precipitating cloud population of the madden julian oscillation over the indian and west pacific oceans 1 the variability of the precipitating cloud population of the madden julian oscillation mjo is represented by statistics of echo features seen by the tropical rainfall measuring mission s precipitation radar over the central indian and west pacific oceans echo features include isolated shallow echoes deep convective cores wide convective cores and broad stratiform regions isolated shallow echoes are ever present but most numerous during suppressed mjo phases broad stratiform regions dominate variability in areal coverage and maximize during active phases deep convective and wide convective cores are more common and variable in number than broad stratiform regions the magnitude of variability is similar in both regions in the central indian ocean active mjo phases have synchronous maximization of deep convective entities in the west pacific broad stratiform regions maximize prior to wide convective cores reanalysis indicates that isolated shallow echoes are most numerous in dry mid tropospheric conditions and strong low level 1000 750 hpa shear mid tropospheric moisture increases before deeper convective features increase in number maximizes as deep convective features maximize and decreases as wide convective cores and broad stratiform regions decline in population active stage deep and wide convective cores occur preferentially with moist mid tropospheric conditions and strong low level shear acute shear may favor downdraft momentum transport and consequently more robust gust front convective triggering broad stratiform regions maximize with a moist mid troposphere strong low level shear and moderate upper level 750 500 hpa shear that is not so strong that the stratiform region disconnects from its convective moisture source

monitoring velocity variations in the crust using earthquake doublets an application to the calaveras fault california we present a technique that greatly improves the precision in measuring temporal variations of crustal velocities using an earthquake doublet or pair of microearthquakes that have nearly identical waveforms and the same hypocenter and magnitude but occur on different dates we compute differences in arrival times between seismograms recorded at the same station in the freqency domain by cross correlation of short windows of signal a moving window analysis of the entire seismograms including the coda gives t the difference in arrival times versus running time along the seismogram the time resolution of the method is an order of magnitude better than the digitization interval the t technique is illustrated with a pair of microearthquakes m 1 7 and 2 0 that occurred before and after the coyote lake california earthquake m 5 9 of august 6 1979 and on the same segment of the calaveras fault that ruptured during the earthquake the coda wave arrivals for some stations are progressively delayed for the second earthquake in the doublet so that its seismogram appears as a stretched version of the earlier event we interpret this systematic variation in t along the coda as a change in the average s velocity in the upper crust in the time interval between the two doublets s wave velocities appear to have decreased by 0 2 in an oblong region 5 10 km in radius at the south end of the aftershock zone

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

accurate fault mechanism determinations for a 1984 earthquake swarm at campi flegrei caldera italy during an unrest episode implications for volcanological research we have analyzed 42 microearthquakes 1 ml 3 that occurred at campi flegrei volcanic area during an intense swarm like activity more than 500 events in half a day in the last period of strong ground uplift 1982 1984 focal mechanisms of these earthquakes have been computed by a probability method which uses p wave polarity and s wave polarization data composite focal mechanisms for different groups of earthquakes have also been computed by the same technique results show a well defined fault plane in agreement with the elongation of the epicentral pattern the orientation and dip of this fault plane together with other observations about hypocenter locations and focal mechanisms of the whole seismicity accompanying the ground uplift episode suggest the presence of an elliptical fracture system at the caldera center this fracture system dipping toward the center of the caldera should represent the limit of the most recent caldera collapse which is also indicated by a negative bouguer gravity anomaly moreover an important differential feature among various groups of earthquakes has been shown namely a rotation up to about 30 of the strike of the compressive stress axis between the easternmost and the westernmost events the resulting pattern indicates that the axis is always oriented towards the town of pozzuoli which roughly represents the very center of the caldera and also the center of symmetry of the ground deformation these observations strongly suggest that earthquakes are generated by the variation of the stress field associated with the deformation along prefractured zones because of their greater weakeness this study provides then the first direct evidence that both seismicity and ground deformations have a common origin

equatorial dry air intrusion and related synoptic variability in mjo initiation during dynamo abstractdynamics of the madden julian oscillation dynamo was conducted over the equatorial indian ocean io from october 2011 to march 2012 during mid to late november a strong madden julian oscillation mjo event denoted mjo 2 initiated in the western io and passed through the dynamo observation array dry air intrusions associated with synoptic variability in the equatorial region played a key role in the evolution of mjo 2 first a sharp dry air intrusion surging from the subtropics into the equatorial region suppresses convection in the itcz south of the equator this diminishes subsidence on the equator associated with the itcz convection which leads to an equatorward shift of convection it is viewed as a contributing factor for the onset of equatorial convection in mjo 2 once the mjo convection is established a second type of dry air intrusion is related to synoptic gyres within the mjo convective envelope the westward propagating gyres draw drier air from the subtropics into the equa

water s two height scales the moist adiabat and the radiative troposphere summary the temperature structure of the tropical troposphere resembles a moist adiabat with a lapse rate transition toward dry adiabatic where water becomes scarce at an altitude hma n 8 km 350 hpa infrared emission by water vapour cools a deeper layer extending up to hd 14 km 160 ma five consequences of these unequal heights are reviewed 1 upper tropospheric relative humidity is often low highly variable and bimodal due to the rapidity of drying by radiative subsidence 2 large scale divergent circulations e g equatorial u wind exhibit a two celled vertical structure with an elevated convergence layer near 8 10 km in the rising branch 3 the dominant deep convective heating process changes from latent heating at low levels to eddy heat flux convergence in the upper troposphere this requires a substantial updraught environment temperature difference which leads to large entrainment near hma yielding stratiform anvil clouds which also contribute radiative heating 4 the rising branches of deep hd vertical circulations export more heat than they import as moisture so that large scale tropical dynamics can be characterized by a gross moist stability 5 divergent motions with a vertical wavelength 8 km corresponding to kelvin or gravity wave speeds of 15 m s are excited by simple e g uniform heating profiles extending through the lapse rate change near hma

a young solidification age for the lunar magma ocean abstract the time at which the lunar magma ocean solidified can be determined from the lu hf isotope systematics of lunar rocks derived from magma sources that formed during crystallization of the lunar magma ocean the final magma ocean crystallization product termed urkreep is enriched in incompatible elements including k ree and p we have determined the initial hf isotopic compositions of four samples two kreep basalts and two mg suite norites the incompatible trace element compositions of these samples are controlled by an urkreep component and therefore the initial hf isotopic compositions of these samples represent the hf isotopic evolution of urkreep in order to correct the effects of neutron irradiation on the hf isotopic compositions of these samples we have developed a model that uses the stable hf and sm isotopic compositions measured on an irradiated sample to determine and correct for the thermal and epithermal neutron fluence that has modified the hf isotopic composition of the sample we use our corrected results to calculate a 176 lu 176 hf urkreep model age of 4353 37 ma and the 176 lu 177 hf of urkreep to be 0 0153 0 0033 the lu hf model age is concordant with the re calculated sm nd urkreep model age of 4389 45 ma and we take the average of these ages 4368 29 ma to represent the time at which urkreep formed this age is concordant with the age of the most reliably dated ferroan noritic anorthosite as well as 142 nd model ages for the formation or re equilibration of mare basalt sources taken together these ages indicate that the moon experienced a widespread large scale magmatic event around 4370 ma most plausibly attributed to solidification of the lunar magma ocean

vertical diabatic heating structure of the mjo intercomparison between recent reanalyses and trmm estimates abstractcapitalizing on recently released reanalysis datasets and diabatic heating estimates based on tropical rainfall measuring mission trmm the authors have conducted a composite analysis of vertical anomalous heating structures associated with the madden julian oscillation mjo because diabatic heating lies at the heart of prevailing mjo theories the intention of this effort is to provide new insights into the fundamental physics of the mjo however some discrepancies in the composite vertical mjo heating profiles are noted among the datasets particularly between three reanalyses and three trmm estimates a westward tilting with altitude in the vertical heating structure of the mjo is clearly evident during its eastward propagation based on three reanalysis datasets which is particularly pronounced when the mjo migrates from the equatorial eastern indian ocean eeio to the western pacific wp in contrast this vertical tilt in heating structure is not readily seen in the three trmm product

concentrations of radioactive elements in lunar materials as an aid to interpreting data obtained remotely on the distribution of radioactive elements on the lunar surface average concentrations of k u and th as well as al fe and ti in different types of lunar rocks and soils are tabulated the u th ratio in representative samples of lunar rocks and regolith is constant at 0 27 k th ratios are more variable because k and th are carried by different mineral phases in nonmare regoliths at the apollo sites the main carriers of radioactive elements are mafic i e 6 8 fe impact melt breccias created at the time of basin formation and products derived therefrom

subsurface temperatures and crustal strength changes within the seismogenic layer at arroyo del coyote in the socorro seismic area central rio grande rift new mexico from 1962 to 1995 572 events with moment magnitudes greater than 1 3 occurred in the socorro seismic area the activity seems to be related to uplift resulting from magma replenishment of a cogeographical magma body at 19 km depth a distinct microearthquake swarm at arroyo del coyote where focal depths are well determined a nearby reliable heat flow measurement and a largely granitic upper crust make the site ideal for considering upper crustal strength inferred from experimentally determined elastic moduli as a function of temperature and confining pressure at in situ conditions the experimental data may be interpreted to imply that strength across the seismogenic layer 6 10 km is much more dependent upon in situ temperatures than in situ stresses normalized young9s moduli and bulk moduli decrease at temperatures predicted for the seismogenic layer at arroyo del coyote the elastic moduli versus depth profile can be explained by the thermoelastic response of microcracking it is suggested that the effect of microcracking weakens the rock and therefore the asperity and surface strength along fault surfaces where seismic events likely occur the seismogenic layer is also within a temperature regime that generally corresponds to the temperature regime for a semibrittle zone model of crustal weakening with possible plastic deformation both the elastic moduli data and the semibrittle zone temperature regime suggest the seismic layer at arroyo del coyote is a layer of crustal weakening with depth different from a stronger crust with depth across a seismogenic layer as often presented in frictional resistance models whereas temperatures at the base of the arroyo del coyote swarm are consistent with in situ plastic deformation and the lack of upper crustal earthquakes at deeper depths the experimental data for elastic moduli at these same temperatures indicate elastic deformation the conflicting character of deformation between experimental and in situ observations illustrates the dependence of rheology on strain rate

petrogenesis and chronology of lunar meteorite northwest africa 4472 a kreepy regolith breccia from the moon northwest africa nwa 4472 is a polymict lunar regolith meteorite the sample is kreep rich high concentrations of potassium rare earth elements and phosphorus and comprises a heterogeneous array of lithic and mineral fragments these clasts and mineral fragments were sourced from a range of lunar rock types including the lunar high magnesian suite the high alkali suite kreep basalts mare basalts and a variety of impact crater environments the kreep rich nature of nwa 4472 indicates that the sample was ejected from regolith on the nearside of the moon in the procellarum kreep terrane and we have used lunar prospector gamma ray remote sensing data to show that the meteorite is most similar to and most likely sourced from regoliths adjacent to the imbrium impact basin u pb and pb pb age dates of nwa 4472 phosphate phases reveal that the breccia has sampled pre nectarian 4 35 ga rocks related to early episodes of kreep driven magmatism some younger phosphate u pb and pb pb age dates are likely indicative of impact resetting events at 3 9 4 ga consistent with the suggested timing of basin formation on the moon our study also shows that nwa 4472 has sampled impact melts and glass with an alkali depleted incompatible trace element rich high sc low rb th ratios low k compositional signature not related to typical apollo high k kreep or that sampled by kreepy lunar meteorite sayh al uhaymir sau 169 this provides evidence that there are numerous sources of kreep rich protoliths on the moon

apollo 14 mare basalts petrology and geochemistry of clasts from consortium breccia 14321 eleven mare basalt clasts have been extracted from polymict lunar breccia 14321 for a combined petrologic and geochemical study by our consortium ten of these clasts are high al low ti mare basalts similar to those discovered previously at apollo 14 the other is a highly evolved tridymite ferrobasalt with low al and intermediate ti contents a high al ilmenite ferrobasalt from lunar breccia 14305 is the most evolved high al basalt described from the apollo 14 site the major and trace element characteristics of the basalts studied here allow them to be grouped into five compositional types that range from lree depleted to lree enriched some of these types may be related by varying percents of partial melting of the same source but at least two separate sources that differ by a factor of two in incompatible trace element concentrations are required the 14321 type basalts and vitrophyres have steep chondritenormalized hree slopes and may have formed by assimilation of intermediate k fra mauro kreep which is presumed to represent a partial melt of the lower crust the age of these basalts 3 9 aeons suggests that mare volcanism played an important role in the evolution of the early lunar crust

the vertical structure of toga coare convection part ii modulating influences and implications for diabatic heating abstract the temporal variability of western pacific warm pool convection especially its vertical structure is examined in this study distributions of convective echo top heights and 30 dbz contour heights have been produced from shipboard radar data collected during tropical ocean global atmosphere coupled ocean atmosphere response experiment toga coare elevation and suppression of convective heights was primarily influenced by the phase of the intraseasonal oscillation iso with heights being suppressed during convectively inactive and westerly wind burst wwb phases of the iso echo top heights were greatest during the convective phases and post wwb phases of the iso however at least some very deep convection was always present within the area observed by radar indicating that local conditions were favorable for deep convection even when the large scale environment was not capable of supporting widespread deep convection in addition to the iso echo top and 30 dbz contour heights were als

eastward propagating intraseasonal oscillation represented by chikira sugiyama cumulus parameterization part ii understanding moisture variation under weak temperature gradient balance abstractthe eastward propagating intraseasonal oscillation represented by the chikira sugiyama cumulus scheme in a general circulation model was investigated focusing on the variation of the free tropospheric humidity the net effect of the vertical advection and cloud process amplifies the positive moisture anomaly in the mature phase supporting the moisture mode theory the horizontal advection causes the eastward propagation of the field the variation of the moisture profile is accurately understood by using environmental vertical velocity outside cumuli the velocity is regulated by a thermodynamic balance under a weak temperature gradient a nondimensional parameter plays an important role in the moisture variation which characterizes the efficiency of moistening drying induced by external heating cooling in the middle and lower troposphere the major moistening factor is the radiative warming anomaly which induces the upward environmental vertical velocity anomaly the reevaporation of th

metasomatic products of the lunar magma ocean the role of kreep dissemination the origin of the incompatible element rich lunar component kreep is in the lunar magma ocean lmo the fractionated residual melt after crystallization of the lmo represents urkreep after warren and wasson 1979 the percentage of this residual melt is low enough to be within the realm of silicate liquid immiscibility sli this process has the ability to split the kreep signature into k and reep fractions which are manifest as lunar granite k and phosphate phases present in highland lithologies or as quartz ferrotroctolite in lunar soils reep we envisage this as a localized but significant process since only a small portion of urkreep undergoes sli norms of experimental and apollo 15 basaltic immiscible glasses suggest that thevreep fraction found in the lunar highlands has undergone post sli fractionation of at least fayalite this significantly reduces the density of the reep fraction and coupled with its low viscosity 10 15 poise it can percolate upward metasomatizing the lunar crust the higher viscosity of the granitic melt 30000 poise inhibits its mobility and it forms pods in the lower rust as required for vhk basalt petrogenesis with the identification of kreepy components the composition of urkreep can be calculated using experimental evidence the kreep components may be recombined to give the pre sli composition or liquid liquid kd s can be used to calculate a pre sli composition from lunar granite both calculated urkreep compositions are lower in mgo and al2o3 and higher in feo and p2o5 than reported low and high k kreep compositions the calculated ree abundances are higher and the ree profiles are slightly more lree enriched than the previously reported kreep compositions however the ree profile calculated using liquid liquid kd s is concave upwards compared to the lree enriched profile produced by recombining the kreep components pre sli whitlockite apatite fractionation occurred prior to immiscibility in order to generate the concave upwards profile the lree enriched profile represents the pre sli magma prior to phosphate fractionation the presence of superkreepy rock types can be accounted for by k and reep fraction assimilation and the compositions of olivine vitrophyres can now be modeled using analyzed lunar rock types without the inference of a mythical high mg component other more widespread kreepy rocks e g apollo 14 breccias apollo 15 kreep basalts lkfm basalts are produced by incorporation of the more widespread pre sli urkreep component the splitting of kreep into identifiable lithological components allows the petrogenesis and role of kreep in lunar evolution to be better understood

the intraseasonal 30 50 day oscillation of the australian summer monsoon abstract the tropical intraseasonal 30 50 day oscillation manifests itself in the australian summer monsoon by a pronounced modulation of the monsoonal westerlies these 30 50 day fluctuations of the monsoonal westerlies are coherent with rainfall and olr across northern australia the olr fluctuation originates in the indian ocean and systematically propagates eastward at 5 m s 1 consistent with previous studies of the intraseasonal oscillation the detailed evolution of the intraseasonal oscillation of the monsoon is studied via composites of upper air data in and about the australian tropics during the summer periods 1957 87 91 events were identified at darwin australia the composite oscillation at darwin has a very deep baroclinic structure with westerlies extending up to 300 mb the westerly phase lasts about ten days and lags a similar duration rainfall event by about four days during the westerly phase the upper troposphere is warm and the extreme lower troposphere is cool this structure

a lower crustal extension to a midcrustal magma body in the rio grande rift new mexico a prominent and spatially localized phase arriving approximately 4 s after the initial compressional arrival repeatedly observed on seismograms recorded in the central rio grande rift from intermediate and deep focus earthquakes at distances near 90 is identified as a probable compressional to shear wave conversion from a lower crustal root of the socorro midcrustal magma body smb this phase is inconsistent with previously determined crustal models containing a simple sill like midcrustal magma body with a negligible conduit system finite element synthetic seismogram modeling suggests that a partially molten root with a western boundary dipping steeply to the east extends several kilometers from the 19 km deep upper surface of the magma body down into the lower crust of the southwestern portion of the albuquerque belen basin the location and geometry of this feature suggest that the intracrustal intrusion of mantle magmas responsible for the ongoing inflation of the smb and associated seismicity is occurring via an off axis conduit system located beneath the active margin of the albuquerque belen basin

characteristics of the october 2005 microearthquake swarm and reactivation of similar event seismic swarms over decadal time periods near socorro new mexico seismicity in the rio grande rift in central new mexico southwestern united states has been dominated by microearthquakes occurring above the midcrustal socorro magma body smb for at least the past century the smb is a sill like feature 3400 km2 in area with a top surface at 19 km depth and centered below the inner rift half graben system a recent swarm of microearthquakes above the magma body began on 20 october 2005 the activity intensified toward 30 october 2005 with the largest event being a shallow felt local magnitude m l 2 4 earthquake at 02 57 35 utc seismicity increased in the region following this event with over 1600 earthquakes detectable at a minimum of one local seismic station during the subsequent month seismic waveforms for the earthquakes in this sequence are remarkably similar implying consistently similar location and faulting geometry the time space distribution of earthquakes indicates that this sequence is highly swarmlike in contrast to tectonic mainshock aftershock sequences given the local tectonic setting and shallow 8 km depth of individual events above the smb a likely explanation for the socorro earthquake sequence is fluid flow or pressure induced triggering associated with the evolution of the smb swarms such as the 2005 sequence are not uncommon in this area e g prominent previous sequences occurred in may and july of 1983 here we characterize the 2005 earthquake sequence by presenting composite focal mechanisms magnitude estimates and high precision relative locations based on waveform cross correlation techniques that capitalize on the similar waveforms a new waveform scanning technique identifies over 1600 small similar earthquakes during this period from continuous seismic records waveforms and locations are also observed to be similar between the 2005 and 1983 sequences suggesting consistency in source location geometry and thus mechanism over decadal time scales

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

evidence for on going inflation of the socorro magma body new mexico from interferometric synthetic aperture radar imaging interferometric synthetic aperture radar insar imaging of the central rio grande rift new mexico usa during 1992 1999 reveals a crustal uplift of several centimeters that spatially coincides with the seismologically determined outline of the socorro magma body one of the largest currently active magma intrusions in the earth s continental crust modeling of interferograms shows that the observed deformation may be due to elastic opening of a sill like intrusion at a rate of a few millimeters per year despite an apparent constancy of the geodetically determined uplift rate thermodynamic arguments suggest that it is unlikely that the socorro magma body has formed via steady state elastic inflation

apollo 17 kreepy basalts evidence for nonuniformity of kreep breccia 72275 contains pristine kreepy basalt clasts that are not found among other samples collected at apollo 17 these basalts occur as discrete clasts and as clasts enclosed within basaltic microbreccias mineral and whole rock chemical analyses reveal that the microbreccias are compositionally indistinguishable from the basalt clasts samples of the 72275 matrix also have the same compositions as the basalts and the basaltic microbreccias 72275 was assembled in situ from a single flow or series of closely related flows of apollo 17 kreepy basalt before it was transported to the apollo 17 site as a rock type apollo 17 kreepy basalts are distinct from apollo 15 kreep basalts the apollo 17 samples have lower ree concentrations steeper negative slopes of the hree and are less magnesian than the apollo 15 samples the two basalt types cannot be related by fractional crystallization partial melting or assimilation this is evidence for the compositional nonuniformity of kreep as a function of geography

the origin and evolution of lunar high ti basalts periodic melting of a single source at mare tranquillitatis abstract five groups of basalts a b1 b2 b3 d with three principal ages exist at the apollo 11 site these range from the low k low rare earth element ree groups b1 b2 and b3 to the low k high ree group d basalts to the high k high ree group a basalts the group a basalts are the only high k 0 2 wt k2o basalts and youngest with an age of 3 59 02 ga groups b3 and b1 are 3 71 02 and 3 67 02 ga respectively group b2 basalts are the oldest at 3 85 02 ga group d basalts have not been dated fractionation modelling for major and trace elements indicates that the b1 basalts could have formed from a b3 like parent liquid the b2 and d basalts can also be related to liquids similar to the b3 b1 composition through the presence of varying amounts of modal whitlockite thus the entirety of low k high ti basalts at apollo 11 may have formed through melting of the same source region the group a basalt compositions are consistent with formation from a different parent liquid with the composition of apollo 11 orange glass modelling of major and trace elements in the apollo 11 orange glass indicate that the composition of the group a basalts is consistent with fractionation of this glass coupled with some assimilation 7 5 15 of an evolved kreep like material however this component is much younger than primitive kreep 4 4 ga this neukreep component similar to the composition of quartz monzodiorites described from the apollo 15 site probably represents evolved material formed during plutonism prior to the formation of the apollo 11 orange glass liquid

analysis of the magnitude frequency distribution for the 1983 1984 earthquake activity of campi flegrei italy vilardo g alessio g and luongo g 1991 analysis of the magnitude frequency distribution for the 1983 1984 earthquake activity of campi flegrei italy in g luongo and r scandone editors campi flegrei j volcanol geotherm res 48 115 125 the magnitude frequency distribution of earthquakes is one of the statistical relationships most frequently used to study the seismicity of a region in this paper the gutenberg richter frequency magnitude relationship is applied to the 19831984 earthquake sequence of campi flegrei italy in order to estimate the space time variation of the b value and its possible correlation with other geophysical parameters in the sequence the investigated region has been divided into three areas on the basis of differences in seismic activity a to the west of pozzuoli where seismicity occurred mostly as swarms b to the east of pozzuoli where events mostly included single high energy earthquakes and c in the western sector of the gulf of pozzuoli moreover b value estimates have been carried out according to different hypocentral depths of all seismic events in the sequence the obtained results have shown strong depth variations of the b value which might reflect important differences in failure conditions at different depths furthermore a certain complexity in the shape of the obtained distribution functions n m has been pointed out temporal variations of b value computed both for the whole region and the different selected areas seem to be meaningful because they do not depend on the number of shocks an the data overlap and the magnitude step am the rates of change of b value ab at compared with the changing rates of seismic energy release ae at do not show a consistent correlation hence the ab at curve cannot be interpreted as a precursor to the other in any systematic way

limited dynamic earthquake triggering in the socorro magma body region rio grande rift new mexico abstract dynamic earthquake triggering the process through which stresses transmitted through the passage of seismic waves can trigger remote faults to fail has been shown to be fairly common throughout the globe and especially in seismically active areas of high heat flow and geothermal activity we explore the possibility of dynamic earthquake triggering around the socorro magma body a feature within the rio grande rift in new mexico that exhibits high heat flow and heightened seismicity because the area fits the environment type in which triggering preferentially occurs we examine 319 global mainshocks with m w 6 0 for the possibility of increased seismicity rates following the passage of the mainshock waves we examine local event locations and origin times relative to mainshock phase arrivals for patterns distinguishing triggering mainshocks from nontriggering mainshocks we find a small triggering response during the time period analyzed unlike following the 2002 denali fault earthquake dfe this small response corresponds to smaller peak dynamic stresses than are found in other triggering studies m w 7 0 at a regional to small teleseismic distance

a revised conceptual model of the tropical marine boundary layer part ii detecting relative humidity layers using bragg scattering from s band radar abstractpersistent layers of enhanced equivalent radar reflectivity factor and reduced spectral width were commonly observed within cloud free regions of the tropical marine boundary layer tmbl with the national center for atmospheric research s pol radar during the rain in cumulus over the ocean rico field campaign bragg scattering is shown to be the primary source of these layers two mechanisms are proposed to explain the bragg scattering layers bsls the first involving turbulent mixing and the second involving detrainment and evaporation of cloudy air these mechanisms imply that bsls should exist in layers with tops bases defined by local relative humidity rh minima maxima the relationship between bsls and rh is explored an equation for the vertical gradient of radio refractivity n is derived and a scale analysis is used to demonstrate the close relationship between vertical rh and n gradients this is tested using the derived radar bsl boundary altitudes 131 surface based soundings

mapping active magma chambers by b values beneath the off ito volcano japan the b value of the frequency magnitude relation and thus the mean magnitude in the off ito volcanic area is not uniform based on detailed b value tomography using about 10 000 events in an area of 10 km radius and in the upper 15 km of the crust a high b value anomaly b 15 below 7 km depth and with a radius of about 2 km located below the coast southeast of ito contrasts with lower values of typically b 0 7 north of it and at shallower depths on the basis of surface deformations a tensile crack dislocation source was located above 7 km depth thus we surmise that the magma chamber in the off ito area was located below 7 km depth the correlation of a high b value anomaly with this model supports our hypothesis that active magma chambers may be mapped by high b value anomalies the magma body may be described as consisting of two parts a lower well established chamber below 11 km depth and a shallower part 11 7 km depth the b value in the volume surrounding the magma chamber increased from 0 7 during the 1980s to 1 5 during the earthquake swarms of the 1990s this may reflect a trend of increasing crack density due to the intrusion activity

diurnal cycle of convection during the 2004 north american monsoon experiment abstract the diurnal cycle of summer monsoon convection in the coastal mountainous region of northwestern mexico is investigated using data from the 2004 north american monsoon experiment name data from a special sounding network consisting of research and operational sites have been quality controlled and combined with surface wind profiler and pibal observations to create a gridded dataset over the name domain this study concentrates on results from the interior portion of the name sounding network where gridded analysis fields are independent of model data special attention is given to surface and pibal observations along the western slope of the sierra madre occidental smo in order to obtain an optimal analysis of the diurnally varying slope flows results show a prominent sea breeze land breeze cycle along the western slopes of the smo there is a deep return flow above the afternoon sea breeze as a consequence of the elevated smo immediately to the east the upslope flow along the western

pre 4 2 ae mare basalt volcanism in the lunar highlands abstract the concept that the plutonism of the lunar highlands and the mare type volcanism are two separate problems in both time 4 4 ae versus apollo 14 breccia 14305 contains a clast 122 which is an olivine gabbronorite that is texturally and mineralogically similar to several apollo 12 basalts e g 12005 12035 12040 it consists of cumulus olivine 40 modal fo 62 70 and ti chromite 2 5 modal post cumulus phases include low ca pyroxene 29 modal wo 7 13 en 68 75 augite 10 modal wo 31 40 en 47 50 plagioclase 15 modal an 82 93 and ilmenite 4 modal 5 7 mgo the tio2 content of this rock 4 3 cao al2o3 1 0 cao 5 1 mgo feo 1 0 mgo 21 9 the ree pattern normalized to chondritic abundances is approximately 30 ch and hump shaped with a pronounced eu depletion and a non kreepy signature a four point rb sr isochron reveals an age of 4 23 0 05 ae the sample has a low initial 87sr 86sr 0 69911 3 the data presented here show that non kreepy mare type volcanism commenced at least as early as 4 2 ae in the fra mauro region and probably across much of the lunar surface massive bombardment during the terminal cataclysm and the subsequent veneer of younger mare basalts has obliturated most of the evidence for these ancient volcanic events these old mare type volcanics may be related to basin forming events such as made procellarum i e impact triggered igneous activity

determining location and magnitude of historical pre 1963 events in the rio grande rift region using intensity information abstract we used intensity information from five calibration earthquakes to estimate an intensity attenuation model for the rio grande rift region encompassing west texas new mexico and southern colorado the attenuation model lies between similar models developed for the basin and range province and central and eastern north america analysis of two test earthquakes occurring in 1931 and 2014 validated that the intensity attenuation relation adequately predicted the events magnitudes and epicenters we then analyzed intensity information for nine historical 1906 1960 earthquakes to determine their magnitudes and epicenters our results indicate that the largest earthquakes of the 1906 socorro new mexico sequence had intensity magnitudes m i 5 7 5 9 and may represent north to south migration of seismicity associated with the socorro magma body moderate earthquakes in 1935 and 1960 also are associated with the magma body the 1938 arizona new mexico border earthquake sequence occurred about 50 km northeast of the ongoing 2014 arizona new mexico border sequence the 17 september earthquake of the 1938 sequence had an m i 4 1 that was about 1 0 units less than that of the 29 june 2014 arizona new mexico event m i 4 9

amplitude and horizontal structure of a large diurnal sea surface warming event during the coastal ocean dynamics experiment abstract intense diurnal warming of the ocean surface was observed in april 1982 off california using a combination of mooring hydrographic and satellite infrared and satellite pigment measurements the event corresponded to a spatial and temooral minimum of the wind stress the diurnal surface temperature amplitude exceeded 6 6 c locally despite a 490 nm optical depth of 20 m suggesting that phytoplankton was not responsible for the shallow heat trapping coherent horizontal temperature streaks at least 50 km long and 4 8 km wide formedduring the subsequent erosion of the shallow warm layers it is hypothesized that thcfr scale was set by planetary boundary layer circulations

frequency magnitude statistics and spatial correlation dimensions of earthquakes at long valley caldera california summary intense earthquake swarms at long valley caldera in late 1997 and early 1998 occurred on two contrasting structures the first is defined by the intersection of a northnorthwesterly array of faults with the southern margin of the resurgent dome and is a zone of hydrothermal upwelling seismic activity there was characterized by high b values and relatively low values of d the spatial fractal dimension of hypocentres the second structure is the pre existing south moat fault which has generated largemagnitude seismic activity in the past seismicity on this structure was characterized by low b values and relatively high d these observations are consistent with lowmagnitude clustered earthquakes on the first structure and higher magnitude divuse earthquakes on the second structure the first structure is probably an immature fault zone fractured on a small scale and lacking a well developed fault plane the second zone represents a mature fault with an extensive coherent fault plane

mechanics of active magmatic intraplating in the rio grande rift near socorro new mexico 1 we investigate long term deformation due to the socorro magma body smb one of the largest active intrusions in the earth s continental crust using interferometric synthetic aperture radar insar observations and finite element simulations insar data spanning 15 years 1992 2007 indicate that the magma body is associated with a steady crustal uplift at a rate of about 2 mm yr 1 previous work showed that while the pattern of surface uplift is consistent with an elastic inflation of a large sill like magma body the smb could not have formed via steady elastic inflation because the latter would be outpaced by magma solidification we resolve this problem using coupled thermo visco elastic models and place constraints on the intrusion history as well as the rheology of the ambient crustal rocks we demonstrate that observations rule out the linear maxwell response of the ductile crust but are consistent with laboratory derived power law rheologies our preferred model suggests that the age of the smb is of the order of 103 years and that the apparent constancy of the present day uplift may be due to slow heat transfer and ductile deformation in a metamorphic aureole of a giant sill like magma intrusion rather than due to a steady increase in the magma overpressure the smb is a contemporaneous example of magmatic intraplating a process by which large volumes of mafic melt stall and spread at midcrustal depths due to density or rheology contrasts

a simulated geochemical rover mission to the taurus littrow valley of the moon we test the effectiveness of using an alpha backscatter alpha proton x ray spec trometer on a remotely operated rover to analyze soils and provide geologically useful informa tion about the moon during a simulated mission to a hypothetical site resembling the apollo 17 landing site on the mission 100 soil samples are analyzed for major elements at moderate analytical precision e g typical relative sample standard deviation from counting statistics si 11 a1 18 fe 6 mg 20 ca 5 simulated compositions of soils are gen erated by combining compositions of components representing the major lithologies occurring at the site in known proportions simulated analyses are generated by degrading the simulated compositions according to the expected analytical precision of the analyzer compositions obtained from the simulated analyses are modeled by least squares mass balance as mixtures of the components and the relative proportions of those components as predicted by the model are compared with the actual proportions used to generate the simulated composition boundary conditions of the modeling exercise are that all important lithologie components of the regolith are known and are represented by model components and that the compositions of these com ponents are well known the effect of having the capability of determining one incompatible element at moderate precision 25 is compared with the effect of the lack of this capability we discuss likely limitations and ambiguities that would be encountered but conclude that much of our knowledge about the apollo 17 site based on the return samples regarding the distribution and relative abundances of lithologies in the regolith could be obtained this suc cess requires however that at least one incompatible element be determined

aspects of interannual and intraseasonal variability of the tropopause and lower stratosphere radiosonde and national centers for environmental prediction national center for atmospheric research reanalysis data are utilized to consider aspects of large scale variability in tropopause height temperature and pressure this variability is related to coherent dynamical fluctuations in the troposphere and lower stratosphere through the use of linear correlation and regression on interannual time scales significant global scale tropopause fluctuations are tied to variability in sea surface temperature sst associated with the el ni o southern oscillation phenomenon when sst is anomalously high in the central tropical pacific tropopause height pressure is high low throughout the tropics with largest perturbation amplitudes in the subtropical pacific at the same time the tropopause is cold over the tropical and subtropical pacific sector but warm elsewhere in the tropics over the extratropics wave like perturbations in the tropopause are seen with anomalous cyclonic flow corresponding to a lower tropopause height and higher tropopause temperature and pressure and vice versa the sign of the temperature anomalies in the lower stratosphere tends to match that at the tropopause over much of the globe with opposite signed anomalies in the upper troposphere the vertical structure of these perturbations is consistent with the expected potential vorticity anomalies induced by quasi stationary rossby waves and vertically propagating gravity waves forced by displacements of tropical convection similar relationships are associated with the eastward propprotion of tropical convection due to the madden julian oscillation on intraseasonal time scales

evolution of the population of precipitating convective systems over the equatorial indian ocean in active phases of the madden julian oscillation three dimensional radar reflectivity fields from a dual wavelength doppler polarimetric radar s polka deployed in the equatorialindian ocean are used to evaluate the composition of the populationof convective cloud elements during active phases of the mjo rainfall in active periods was intermittent occurring in 11 episodesofabout 2 4days separated byseveralnonrainydays dataforthese 2 dayperiodswerecomposited relative to the time of maximum rainfall analysis of the s polka data shows the makeup of the convective population during the rainfall episodes four types of echo structures were analyzed statistically for the 11 rainfallepisodes shallowconvectiveechoes sce deepconvectivecores dcc wideconvectiveechocores wcc and broad stratiform bsr echo regions sce and dcc events were most frequent before the maximum rainfall with the peak frequency of sce leading that of dccs wccs were most frequent during therainfallmaximum and bsr regionswere most frequentinthe later part oftherainfallepisode composited ecmwf interim re analysis era interim data and 3 hourly atmospheric soundings indicate that the 2 4 day episodes were related to the passage of equatorial waves in the early part of a rainfall episode the wave passageconditionswereunstable favoringdeeppenetratingconvectiveelements whileinthelaterperiod the wave divergence profile was commensurate with convective systems in late anvil producing stages these results support the stretched building block notion of the life cycle of tropical convection and confirm satellitebased interpretations of sce dcc wcc and bsr statistics in the composition of the convective population

rb sr and sm nd chronology of an apollo 17 kreep basalt sm nd and rb sr mineral isochrons were determined for an apollo 17 kreep pigeonite basalt clast 543 from breccia 72275 collected from boulder 1 station 2 in the valley of taurus littrow sm nd analyses of the basalt yield a precise mineral isochron age of 4 08 0 07 ga for 147sm 0 00654 ga 1 the rb sr mineral isochron age of 4 13 0 08 ga for 87rb 0 0139 ga 1 is concordant with the sm nd age however the rb sr isotopic system has been slightly disturbed probably by the serenitatis impact event 3 95 ga ago the sm nd age is interpreted as the crystallization age of this apollo 17 kreep basalt ages and initial 87sr 86sr and end values for this basalt and apollo 14 and 15 kreep basalts suggest that these two types of kreep basalts could be produced from sources having similar rb sr and sm nd ratios these new age data suggest that kreep basaltic volcanism started 200 ma earlier than the 3 85 ga age generally accepted from studies of apollo 15 pristine kreep basalts apollo 17 kreep basalts probably pre date the serenitatis impact strongly indicating that not all kreep basaltic volcanism was necessarily related to basin forming impacts the younger apollo 15 and 14 kreep basalts probably are related to the imbrium impact however the ages and end values for kreep basalts granites troctolites and norites from a variety of lunar sites form a linear array corresponding to source s with sm nd lower by 15 than the chondritic value slightly enriched in lree suggesting that these rocks could be genetically related formation of a common sm nd isotopic growth curve by these data is most easily explained by an early moon wide differentiation accompanying the formation and subsequent solidification of a global magma ocean

slip generated patterns of swarm microearthquakes from west bohemia vogtland central europe evidence of their triggering mechanism 1 we investigated space time relations between consecutive events of west bohemian 2000 swarm and their association with the coulomb stress changes induced on a fault plane by prior swarm events a few thousand m 3 3 strike slip swarm earthquakes clustered along a fault plane at depths 6 5 10 5 km and showed common rake angle of 30 in order to disclose earthquake interaction we investigated the space time relations between consecutive earthquakes we determined relative position vectors for each consecutive event pair the prior event and the immediate aftershock ia and we measured time lags between them the resulting cluster of relative position vectors shows a high density of aftershocks near the origin which decays with distance it points out a triggering effect of the prior event upon subsequent aftershocks the spatial distribution of the relative positions disclosed dominance of aftershocks in the slip parallel directions which is manifested by pronounced elongation of the cluster of the relative positions and of the angular dependence of the rate of ias the temporal distribution of the relative positions indicates that some aftershocks prove high interevent velocities and occur systematically at greater distances suggesting the existence of two distinct triggering mechanisms acting at large and small timescales we evaluated the complete coulomb stress change upon the fault plane due to the prior event and showed that the observed space time distribution of the relative positions can be explained by a common effect of both static and dynamic stress changes which act on different distance and timescale

a generalized omori s law for earthquake aftershock decay 1 earthquake aftershock sequences have been found to approximately satisfy three empirical scaling relations i the gutenberg richter frequency magnitude scaling ii bath s law for the difference in the magnitude of a mainshock and its largest aftershock and iii the modified omori s law for the temporal decay of aftershock rates the three laws are incorporated to give a generalized omori s law for aftershock decay rates that depend on several parameters specific for each given seismogenic region it is shown that the characteristic time c first introduced in the modified omori s law is no longer a constant but scales with a lower magnitude cutoff and a mainshock magnitude the generalized omori s law is tested against earthquake catalogs for the aftershock sequences of the landers northridge hector mine and san simeon earthquakes

petrology and provenance of a very low titanium picrite clast in lunar highland regolith breccia 15295 clast 100 in regolith breccia 15295 could be a key to resolving the relationship s between mare basalts and lunar picritic glasses the clast is basaltic with texture mineralogy mineral compositions and calculated bulk composition suggesting that it crystallized in a thick lava flow or shallow intrusive body from a very low titanium vlt basaltic magma the estimated bulk composition of clast 15295 100 is primitive i e magnesian compared to those of known vlt basalts and is very close to those of vlt picritic green glasses especially the apollo 14 a green glass from these similarities we infer that clast 15295 100 is a crystalline product of a picritic magma similar to the apollo 14 a glass clementine and m3 remotely sensed data of the lunar surface were used to find areas that have chemical compositions consistent with those of clast 15295 100 not only near the apollo 15 site but in a broad region surrounding the site two regions are consistent with clast s 15295 100 compositional data the larger region is in southern mare imbrium and a smaller region is in the eastern half of sinus aestuum these locations should be considered as candidates for future missions focusing on sample science

the bay of naples southern italy constraints on the volcanic structures inferred from a dense seismic survey 1 the bays of naples and pozzuoli host volcanic areas that have been active within recent history in addition the vicinities areas around the vesuvius volcano and the campi flegrei caldera are extremely densely inhabited over the past decade this situation has prompted several active seismic experiments focused on the vesuvius volcano more recently the serapis active seismic survey covered the entire bay of naples with particular attention to pozzuoli bay the processed serapis p wave travel time collection extended with a previously acquired data set has allowed the computation of the most comprehensive three dimensional p wave velocity distribution for the bay of naples which includes a small scale high resolution model of the campi flegrei caldera the joint interpretation of the velocity distribution together with both the available gravity measurements and models and the geothermal drilling information has allowed us to locate and map lithological units at depths we propose a model of the campi flegrei caldera in relation to the underlying mesozoic limestone unit in this model no magma chamber exists in the upper 6 km beneath the bay of naples the feeding system of the campi flegrei caldera is directly controlled by the tectonic structures affecting the limestone unit beneath the bay of naples two ne sw normal faults run beneath the vesuvius volcano and campi flegrei which are related to the pre pleistocene apenninic tectonics

annual interannual and intraseasonal variability of tropical tropopause transition layer cirrus cloud fields based on the first three years of data from the cloud aerosol lidar and infrared pathfinder satellite observations calipso mission are used to investigate the relationship between cirrus within the tropical tropopause transition layer ttl and the madden julian oscillation mjo the annual cycle and el nino southern oscillation enso the ttl cirrus signature observed in association with the mjo resembles convectively induced mixed kelvin rossbywavesolutionsabovethepacificwarmpoolregion thissignatureiscenteredtotheeastofthe peak convection and propagates eastward more rapidly than the convection it exhibits a pronounced east ward tilt with height suggestive of downward phase propagation and upward energy dispersion a cirrus maximumisobservedoverequatorialafricaandsouthamericawhentheenhancedmjo relatedconvection enters the western pacific tropical mean ttl cirrus is modulatedby the mjo with more than twice as much ttl cirrus fractional coverage equatorward of 108 latitude when the enhanced convection enters the pacific than a few weeks earlier when the convection is over the indian ocean the annual cycle in cirrus clouds around the base of the ttl is equatorially asymmetric with more cirrus observed in the summer hemisphere higher in the ttl the annual cycle in cirrus clouds is more equatorially symmetric with a maximum in the boreal winter throughout most of the tropics the enso signature in ttl cirrus is marked by a zonal shift of the peak cloudiness toward the central pacific during el nino and toward the maritime continent during la nina

campi flegrei unrest episodes and possible evolution towards critical phenomena mechanical and thermal fluid dynamical contributions to unrest phenomena at active calderas are quantitatively evaluated and a mixed mechanical thermal fluid dynamical model is developed to explain the unrest phenomena at campi flegrei caldera mechanical modelling involves the use of analytical and finite element formulations thermal fluid dynamical effects are considered in the framework of a one dimensional approximation solved by an analytical method the results shed new light about the coupled effect of mechanically and thermally induced perturbations and variations in the geothermal fluid circulation regime unrest episodes at campi flegrei are interpreted in terms of the joint effect of a first essentially mechanical phase due to overpressure in a magma chamber and to a progressive amplification and final decay due to the circulating water the elastic response of the rocks to the migrating front of overpressure is shown to be strongly conditioned by the caldera structure which produces a concentration of strain in the inner part and a stress concentration causing the local seismicity around the caldera borders thermal fluid dynamical effects are also shown to have important implications on the evolution of the volcanic system towards critical phenomena which must be considered for a meaningful evaluation of volcanic hazard

the rio grande rift new electromagnetic constraints on the socorro magma body abstract the socorro magma body in central new mexico is a prime example of an intrusive magma body associated with continental extension in one of the major active rift zones of the world the rio grande rift to study this feature further in particular its relation to large scale features delineated elsewhere beneath the rift in 1988 brown university occupied a sequence of densely spaced 5 10 km wide band 10 4000 s remote referenced three component magnetic variation sites along an east west line which transected the southern margin of the magma body our profile was deployed so as to cross precisely above the center of what has been the most seismically active portion of the structure southwest of socorro complex magnetic transfer coefficients at up to 15 periods from 21 sites along our profile have been inverted to determine two dimensional conductivity models for vertical cross sections transverse to the strike of the rift two independent generalized inverse algorithms are used an overdetermined block inversion and a mixed determined flat continuous resistivity inversion both inversions require the presence of a conducting zone beneath the rift at intermediate depths 15 20 km in the crust this feature has properties which are similar to those of the intracrustal conductor seen elsewhere along the rift in addition to this conducting zone in the deeper crust the data require a more conductive core at shallow depth 10 15 km which appears to be associated with the base of a zone of increased microseismicity described by sanford and his colleagues this latter feature might be a zone of diffuse magmatic intrusions enhanced hydrothermal circulation or a combination of both finally our two inversions suggest that the resistivity structure beneath the western end of our profile which is physiographically adjacent to the colorado plateau has properties which are similar to those reported for interior regions of the plateau

petrogenesis of mare basalts a record of lunar volcanism returned rock and soil samples from our nearest planetary neighbor have provided the basis for much of our understanding of the origin and evolution of the moon of particular importance are the mare basalts which have revealed considerable information about lunar volcanism and the nature of the mantle as well as post magma generation processes this paper is a critical review of the petrogenetic models for the generation of mare basalts formulated over the last twenty years we have used all available mare basalt analyses to define a six fold classification scheme using tio2 contents as the primary division i e 1 wt very low ti or vlt 1 6 wt low ti 6 wt high ti a secondary division is made using al2o3 contents i e 11 wt low al 11 wt high al and a tertiary division is defined using k contents i e 2000 ppm low k 2000 ppm high k such divisions and subdivisions yield a classification containing twelve categories of which six are accounted for by the existing apollo and luna collections therefore we present our discussions in the form of six mare basalt rock types 1 1 high ti low al low k referred to as high ti low k 2 2 high ti low al high k referred to as high ti high k 3 3 low ti low al low k referred to as low ti 4 4 low ti high al low k referred to as high alumina 5 5 low ti high al high k referred to as vhk 6 6 vlt low al low k basalts referred to as vlt a variety of post magma generation processes have been invoked such as fractional crystallization either alone or combined with wallrock assimilation to explain the compositional ranges of the various mare basalt suites in order to evaluate these proposed petrogenetic processes this review is by rock type and is non site specific but for each rock type reference to particular lunar sample return missions is brought forth this permits a comparison of similarities and differences of broadly similar rock types correlated with geography on the moon which in turn allows a more thorough petrogenetic evaluation high ti mare basalts i e high ti low al low k are found at apollo 11 and apollo 17 sites however the a 11 basalts contain lower tio2 abundances a considerably larger range in trace element contents and the only occurrence of high ti high k mare basalts fractional crystallization and source heterogeneity within each site are the keys to understanding the petrogenesis of the high ti basalts low ti basalts including both low al k and high al k varieties are found at apollo 12 14 and 15 and luna 16 sites the low ti basalts exhibit a wide range of major and trace element compositions and require source heterogeneity fractional crystallization and some assimilation the high alumina mare basalts i e low ti high al low k are found at apollo 14 and luna 16 sites and exhibit a wide range of major and trace element compositions however in these examples source heterogeneity is not a major factor indeed fractional crystallization coupled with kreep assimilation particularly for the apollo 14 variants can explain the compositional ranges of these high alumina basalts the vhk mare basalts i e low ti high al high k have been sampled only at the apollo 14 locale and are products of a parental highalumina magma assimilating lunar granite very low ti vlt mare basalts i e vlt low al low k are found at apollo 17 and luna 24 sites fractional crystallization has had a major influence upon the range in vlt compositions but luna 24 vlt basalts have been derived from a source slightly different in composition from that for apollo 17 vlt varieties for example the luna 24 vlt basalts generally exhibit positive eu anomalies a unique property for mare basalts which almost always have negative eu anomalies the concept of a lunar magma ocean lmo is generally accepted and source modelling of all basalts invokes a mafic lmo cumulate source this is the only unifying model for mare basalt petrogenesis but the semantics and logistics of it are and will be debated for many years for example major convective overturn of the lmo appears plausible but whether this occurred on a local or planet wide scale to produce source heterogeneity remains to be determined

the great lunar hot spot and the composition and origin of the apollo mafic lkfm impact melt breccias thorium rich mafic impact melt breccias from the apollo 14 17 missions that is those breccias identified with the composition known as lkfm are regarded largely as products of basin forming impacts that penetrated the feldspathic crust and sampled underlying mafic material and magma ocean residuum carrying the compositional signature of kreep potassium rare earth elements phosphorous despite considerable compositional variation among such breccias compositions of all of them correspond to mixtures of only four components 1 a norite with composition generally similar to that of apollo 15 basalt mean abundance 58 range 30 95 2 fo 90 dunite mean 13 range 1 27 3 feldspathic upper crust mean 29 range 4 50 and feni metal 0 1 1 7 petrographic evidence has shown that much of the feldspathic component but none of the kreep component is clastic this observation and the high proportion of kreep norite component in the breccias suggest that the melt zone of the impact or impacts forming the breccias contained little feldspathic material but consisted predominantly of material with the average composition of kreep norite the dunite component probably derives ultimately from the upper mantle these conclusions support the hypothesis that the breccias were not formed in typical feldspathic crust but instead by one or more impacts into what is designated here the great lunar hot spot that is the anomalous th rich terrane in the imbrium procellarum area identified by the apollo and lunar prospector gamma ray spectrometers the lkfm composition is a special product of the great lunar hot spot and is not the average composition of the lower crust in typical feldspathic highlands similarly mg suite and alkali suite plutonic rocks of the apollo collection are likely all differentiation products of the hot spot not of plutons that might occur in typical feldspathic crust

development characteristics and dynamic structure of tropical intraseasonal convection anomalies abstract the development and dynamical structure of intraseasonal low frequency convection anomalies in the equatorial region are investigated using 10 years 1975 85 of outgoing longwave radiation olr and 7 years 1979 85 of 200 and 850 mb wind data the composite olr anomalies for 36 cases show a four stage development process initiation over equatorial africa rapid intensification when passing through the indian ocean mature evolution characterized by a weakening in the maritime continent and redevelopment over the western pacific and dissipation near the date line in moderate events or emanation from the equator toward north america and southeastern pacific in strong events a noticeable feature in vertical structure is that the 850 mb convergence leads convection and midtropospheric upward motion by about 30 degrees longitude in both developing and mature phases equatorial upper lower level easterly westerly anomalies and associated twin anomalous anticyclonic cyclonic circulation an

microphysical characteristics of mjo convection over the indian ocean during dynamo the microphysical characteristics of precipitating convection occurring in various stages of the madden julian oscillation mjo over the indian ocean are determined from data obtained from the national center for atmospheric research dual polarimetric doppler s band radar s polka deployed as part of the dynamics of the mjo dynamo field experiment active mjo events with increased rainfall occurred in october november and december 2011 during each of these active mjo phases in addition to enhanced rainfall convection became deeper and ice phase microphysics played a greater role s polka consistently showed nonoriented small ice particles dominating the radar echoes at altitudes of 9 10 km dry aggregates concentrated between 7 and 9 km and wet aggregates and graupel near the melting level 5 km graupel occurred mainly in actively convective towers while the wet aggregates occurred almost exclusively in the stratiform regions of mesoscale convective systems mcss during each of the three multiweek mjo active phases the maximum rainfall occurred in short bursts lasting a few days each multiday rainy period began with deepening convective elements and a concurrent increase in occurrence of dry aggregates which maximized just prior to organization into mcss the peak rainfall occurrence coincided with the maximum coverage of the radar domain by mcss reflecting large stratiform regions that exhibited the most frequent occurrence of wet aggregates during the december active mjo phase however the mcss were shallower and had a slightly lower tendency for wet aggregates in the stratiform regions and therefore generally weaker brightbands

stress strain changes and triggered seismicity at the geysers california the principal results of this study of remotely triggered seismicity in the geysers geothermal field are the demonstration that triggering initiation of earthquake failure depends on a critical strain threshold and that the threshold level increases with decreasing frequency or equivalently depends on strain rate this threshold function derives from 1 analyses of dynamic strains associated with surface waves of the triggering earthquakes 2 statistically measured aftershock zone dimensions and 3 analytic functional representations of strains associated with power production and tides the threshold is also consistent with triggering by static strain changes and implies that both static and dynamic strains may cause aftershocks the observation that triggered seismicity probably occurs in addition to background activity also provides an important constraint on the triggering process assuming the physical processes underlying earthquake nucleation to be the same gomberg this issue discusses seismicity triggered by the mw 7 3 landers earthquake its constraints on the variability of triggering thresholds with site and the implications of time delays between triggering and triggered earthquakes our results enable us to reject the hypothesis that dynamic strains simply nudge prestressed faults over a coulomb failure threshold sooner than they would have otherwise we interpret the rate dependent triggering threshold as evidence of several competing processes with different time constants the faster one s facilitating failure and the other s inhibiting it such competition is a common feature of theories of slip instability all these results not surprisingly imply that to understand earthquake triggering one must consider not only simple failure criteria requiring exceedence of some constant threshold but also the requirements for generating instabilities

a strontium and neodymium isotopic study of apollo 17 high ti mare basalts resolution of ages evolution of magmas and origins of source heterogeneities abstract a combined sr and nd isotopic study of 15 apollo 17 high ti mare basalts was undertaken to investigate geochronological and compositional differences between previously identified magma types a b1 b2 and c whole rock and mineral separates for one of the least evolved type b1 basalts 70139 yield sm nd and rb sr isochron ages of 3 71 0 12 ga and 3 65 0 13 ga respectively a more evolved type a basalt 71539 exhibits a slightly older sm nd isochron age of 3 75 0 07 ga and a rb sr isochron age of 3 67 0 10 ga although these two ages are non resolvable by themselves compilation of all available geochronological data allows resolution of type a and b1 b2 ages at high levels of confidence 99 the most reliably dated samples classified according to their geochemical type yield weighted average ages of 3 75 0 02 ga for type a n 4 and 3 69 0 02 ga for type b1 b2 n 3 basalts insufficient geochronological data are available to place the rare type c basalts within this stratigraphy we propose that age differences correlate with geochemical magma type and that early magmatism was dominated by eruption of type a basalts while later activity was dominated by effusion of type b1 and b2 basalts whole rock isotopic data yield distinct differences in initial sr and nd isotopic compositions between types a b1 b2 and c basalts types a b1 and c exhibit restricted intra group compositional variations and lie along well defined whole rock isochrons these data are consistent with petrogenetic models involving closed system fractionation of observed microphenocrysts from chemically and isotopically distinct parental magmas in contrast a wide range of type b2 initial isotopic compositions indicates mixing of several distinct components during magma evolution the sm nd whole rock isochron age for type a bl and c basalts of 3 79 0 15 ga is within error of apollo 17 eruptive activity however the very well defined sr whole rock isochron age of 4 02 0 05 ga is 270 to 330 ma older than eruptive ages isotopic and petrological arguments indicate that extensive rb sr fractionation did not occur at the time of melt generation therefore the 4 0 ga sr whole rock isochron age records a significant event at which time geochemical heterogeneities were established within the originally homogeneous basalt source regions types a and c sources were enriched in rb sr with little or no concurrent modification of 87 sr 86 sr sm nd or 143 nd 144 nd infiltration of similar aged kreep magmas into mantle cumulate sources cannot explain both sr and nd isotopic data instead we suggest a metasomatic origin in which rb transported as a chloride complex in halogen rich fluids was preferentially mobilized relative to sr and the rees

post laramide removal of the farallon slab western united states i propose that post laramide removal of the subhorizontally subducting farallon slab occurred by buckling downward along an approximately east northeast trending axis this process was accomplished by a tearing or necking separation of the subducted slab near the northern and southern boundaries of the united states and propagation of the separated edges toward the central axis of downwelling accompanied by aesthenosphic upwelling behind the trailing edges initial buckling probably began near 50 ma and slab removal was complete by 20 ma this model is based primarily on the space time evolution of the ignimbrite flare up a major mid tertiary igneous event of mantle origin which involved two propagating fronts of initiation of volcanism that followed the proposed motions of the separated slab edges as they converged on central nevada from the north and southeast post laramide uplift extension establishment of the cascadia subduction zone and active magmatism may be consequences of lithosphere scale modifications caused by the laramide removal of the slab and the resulting asthenospheric upwelling

new evidence for the existence and internal structure of a thin layer of magma at mid crustal depths near socorro new mexico the characteristics of a strong mid crustal reflector in the rio grande rift southwest of socorro new mexico were studied using high quality digital seismograms of microearthquakes the data are from a tight cluster of hypocenters located almost directly beneath the recording station 2 km cross correlation of the direct and reflected microearthquake s phases yields coefficients which are positive and large in absolute value average 0 79 because these two phases leave the focal region 180 out of phase for this swarm reflection must occur at a discontinuity where a 180 phase shift occurs waveforms for the p wave reflections are not identical from event to event within the swarm the character of the p reflection indicates a magma body with rapid lateral changes in internal structure the spectral characteristics of the reflected p phase are suggestive of constructive interference the near normal incidence geometry of both the reflected and direct p phase implies an essentially common path through the upper crust and near surface phanerozoic rocks for these two phases the earthquakes examined in this study are quite small ml 0 hence the initial portion of the direct p phase may be used as the response function for the path through the upper crust during modeling of the reflected p phase synthetic seismograms which include attenuation effects and interbed multiples were calculated and compared to the observed waveforms the results of modeling the stacked spectra of the pzp phase indicate a thin 70 m layer of nonrigid low velocity material underlain by a second thin 60 m layer of slightly higher velocity material this second layer may be an earlier partially solidified intrusion or a crystalline mush at the base of a single magma chamber the total thickness of the magma body is estimated to be 150 m

kinematic and thermodynamic characteristics of the flow over the western pacific warm pool during toga coare abstract rawinsonde and satellite infrared radiation ir data from the tropical ocean global atmosphere toga coupled ocean atmosphere response experiment coare are used to investigate mean and transient behavior and horizontal variability of the atmosphere over the western pacific warm pool infrared data for the 4 mo intensive observing period iop and vertical motion fields indicate that the intensity of convection height of maximum upward motion and sst all increased from west 140 e to east across the coare domain iop mean ir data show a double itcz intertropical convergence zone structure north and south of the intensive flux array ifa centered at 2 s 156 e although marked variability in the patterns occurred on a month to month basis three prominent westerly wind bursts occurred over the ifa during the 4 mo iop in association with the intraseasonal oscillations isos strong upward motion usually occurred 1 3 weeks prior to the peak low level westerlies subsidence dominated when

earthquake classification location and error analysis in a volcanic environment implications for the magmatic system of the 1989 1990 eruptions at redoubt volcano alaska abstract determination of the precise locations of seismic events associated with the 1989 1990 eruptions of redoubt volcano posed a number of problems including poorly known crustal velocities a sparse station distribution and an abundance of events with emergent phase onsets in addition the high relief of the volcano could not be incorporated into the hypoellipse earthquake location algorithm this algorithm was modified to allow hypocenters to be located above the elevation of the seismic stations the velocity model was calibrated on the basis of a posteruptive seismic survey in which four chemical explosions were recorded by eight stations of the permanent network supplemented with 20 temporary seismographs deployed on and around the volcanic edifice the model consists of a stack of homogeneous horizontal layers setting the top of the model at the summit allows events to be located anywhere within the volcanic edifice detailed analysis of hypocentral errors shows that the long period lp events constituting the vigorous 23 hour swarm that preceded the initial eruption on december 14 could have originated from a point 1 4 km below the crater floor a similar analysis of lp events in the swarm preceding the major eruption on january 2 shows they also could have originated from a point the location of which is shifted 0 8 km northwest and 0 7 km deeper than the source of the initial swarm we suggest this shift in lp activity reflects a northward jump in the pathway for magmatic gases caused by the sealing of the initial pathway by magma extrusion during the last half of december volcano tectonic vt earthquakes did not occur until after the initial 23 hour long swarm they began slowly just below the lp source and their rate of occurrence increased after the eruption of 01 52 ast on december 15 when they shifted to depths of 6 to 10 km after january 2 the vt activity migrated gradually northward this migration suggests northward propagating withdrawal of magma from a plexus of dikes and or sills located in the 6 to 10 km depth range precise relocations of selected events prior to january 2 clearly resolve a narrow steeply dipping pencil shaped concentration of activity in the depth range of 1 7 km which illuminates the conduit along which magma was transported to the surface a third event type named hybrid which blends the characteristics of both vt and lp events originates just below the lp source and may reflect brittle failure along a zone intersecting a fluid filled crack the distribution of hybrid events is elongated 0 2 0 4 km in an east west direction this distribution may offer constraints on the orientation and size of the fluid filled crack inferred to be the source of the lp events

vertical mode decompositions of 2 day waves and the madden julian oscillation abstract vertical structures of 2 day waves and the madden julian oscillation mjo are projected onto vertical normal modes for a quiescent tropical troposphere three modes capture the gross tropospheric structure of 2 day waves while only two modes are needed to represent most of the baroclinic structure of the mjo deep circulations that project onto the first baroclinic mode are associated with deep cumulonimbus and stratiform rainfall shallow circulations that project onto higher wavenumber modes are associated with precipitating shallow cumulus and congestus and stratiform rainfall for both disturbances the horizontal divergence contributed by shallow modes is an important factor in the column integrated moist enthalpy budget these modes converge moist static energy for a time prior to when deep circulations export moist static energy these results highlight the importance of properly representing the effects of shallow cumulus congestus and stratiform precipitation in theories of convective

determination of shear and compressional wave velocity variations and hypocenter locations in a rapidly inflating caldera the campi flegrei during 1982 1985 the campi flegrei caldera underwent a large h 1 7 m rapid hmax 2 mm day 1 and localized radius 6 km uplift p and s arrival times from three component digital seismograms recorded during this period have been used to invert for hypocenter locations and for three dimensional shear and compressional velocity to 3 km first order residual based tomography shows a significant and well resolved high p s ratio anomaly for the volume encompassing the central caldera and the active solfatara crater three dimensional tomographic inversion resolves this central anomaly as a zone of depressed p and s with a high 2 1 p s ratio the three dimensional velocity model and hypocenter distribution are consistent with modeling the central caldera as a zone of nearly water saturated cracks presumably a result of recurrent inflation and deflation in a zone with a shallow water table although the presence of small shallow magma bodies is not precluded

multiscale variability of deep convection in relation to large scale circulation in toga coare deep convection over the indo pacific oceanic warm pool in the tropical ocean global atmosphere coupled ocean atmosphere response experiment toga coare occurred in cloud clusters which grouped together in regions favoring their occurrence these large groups of cloud clusters produced large scale regions of satellite observed cold cloud top temperature this paper investigates the manner in which the cloud clusters were organized on time and space scales ranging from the seasonal mean pattern over the whole warm pool region to the scale of individual cloud clusters and their relationship to the large scale circulation and sea surface temperature sst the dominant convective variability was associated with the intraseasonal oscillation iso a large eastward propagating ensemble of cloud clusters marked the iso s progress the meridional structure of the iso was strongly affected by the seasonal cycle with a southward shift from the northern hemisphere in october november to the southern hemisphere in january february the sst had an intraseasonal signal in lagged quadrature with the cold cloudiness and rainfall in coare the sst increased decreased during the convectively suppressed active phases of the iso enhanced low level westerly winds occurred toward the later stages of the enhanced convection periods of the iso though not always centered at the equator the strongest westerlies tended to be located between two synoptic scale cyclonic gyres which were often not symmetric about the equator in the low level wind field this asymmetry in the anomalous equatorial low level westerlies may have different implications for the oceanic response in the coupled atmosphere ocean system than those centered on the equator the cyclonic gyres contained highly concentrated deep convection and in four cases the gyres developed into tropical cyclones within the envelope marking the convectively active phase of the iso cloud clusters were frequently concentrated into westward propagating disturbances with a local periodicity of similar to 2 days these 2 day disturbances have been identified in earlier spectral studies and appear to be related to westward propagating inertio gravity waves in coare they typically contained numerous cloud clusters which underwent a distinct diurnal cycle most of the cloud clusters embedded in the 2 day disturbances moved westward though some were stationary and a few moved eastward a cloud duster tracking program identified groups of clusters lime dusters that exhibited continuity in time and space in the most convectively active period of the iso the tracking program identified almost the entire iso cloud ensemble as a long lasting trackable superconvective system this observation indicates the lack of a distinct scale separation between convection and large scale disturbances during the most intense convective periods in coare

clouds associated with the madden julian oscillation a new perspective from cloudsat abstractthe evolution of total cloud cover and cloud types is composited across the madden julian oscillation mjo using cloudsat data for june 2006 may 2010 two approaches are used to define mjo phases 1 the local phase is determined at each longitude and time from filtered outgoing longwave radiation and 2 the global phase is defined using a popular real time multivariate mjo rmm index which assigns the tropics to an mjo phase each day in terms of local phase cloudsat results show a familiar evolution of cloud type predominance in the growing stages shallow clouds coexist with deep intense but narrow convective systems widespread cloud coverage and rainfall appear during the active phases becoming more anvil dominated with time and finally suppressed conditions return results are compared to the convectively coupled kelvin wave which has a similar life cycle to the mjo convection in the mjo tends to be modulated more by moisture variations compared to the kelvin wave in terms of globa

the 2002 2003 el nino recorded in australian cave drip waters implications for reconstructing rainfall histories using stalagmites 1 a 30 month study of drip hydrochemistry from kooringa cave eastern australia revealed a clear geochemical response to the 2002 2003 el nino through the drought drip discharge fell to base flow drip ca2 concentrations fell by half and drip mg ca and sr ca increased in a co varying pattern calcite mg ca and sr ca predicted from drip waters displayed a marked increase through and just beyond the period of greatest moisture deficit the results suggest that stalagmites from shallow caves in drought sensitive eastern australia potentially preserve a valuable record of el nino la nina history

magma intrusion near volcan tancitaro evidence from seismic analysis abstract between may and june 2006 an earthquake swarm occurred near volcan tancitaro in mexico which was recorded by a temporary seismic deployment known as the mars network we located 1000 events from this seismic swarm previous earthquake swarms in the area were reported in the years 1997 1999 and 2000 we relocate and analyze the evolution and properties of the 2006 earthquake swarm employing a waveform cross correlation based phase repicking technique hypocenters from 911 events were located and divided into eighteen families having a correlation coefficient at or above 0 75 90 of the earthquakes provide at least sixteen phase picks we used the single event location code hypo71 and the p wave velocity model used by the jalisco seismic and accelerometer network to improve hypocenters based on the correlation adjusted phase arrival times we relocated 121 earthquakes which show clearly two clusters between 9 10 km and 3 4 km depth respectively the average location error estimates are

shallow seismicity triggered seismicity and ambient noise tomography at the long dormant uturuncu volcano bolivia using a network of 15 seismometers around the inflating uturuncu volcano from april 2009 to 2010 we find an average rate of about three local volcano tectonic earthquakes per day and swarms of 5 60 events a few times per month with local magnitudes ranging from 1 2 to 3 7 the earthquake depths are near sea level more than 10 km above the geodetically inferred inflation source and the altiplano puna magma body the mw 8 8 maule earthquake on 27 february 2010 triggered hundreds of earthquakes at uturuncu with the onset of the love and rayleigh waves and again with the passage of the x2 x3 overtone phases of rayleigh waves this is one of the first incidences in which triggering has been observed from multiple surface wave trains the earthquakes are oriented nw se similar to the regional faults and lineaments the b value of the catalog is 0 49 consistent with a tectonic origin of the earthquakes we perform ambient noise tomography using love wave cross correlations to image a low velocity zone at 1 9 to 3 9 km depth below the surface centered slightly north of the summit the low velocities are perhaps related to the hydrothermal system and the low velocity zone is spatially correlated with earthquake locations the earthquake rate appears to vary with time a seismic deployment from 1996 to 1997 reveals 1 5 earthquakes per day whereas 60 events day were seen during 5 days using one seismometer in 2003 however differences in analysis methods and magnitudes of completeness do not allow direct comparison of these seismicity rates the rate of seismic activity at uturuncu is higher than at other well monitored inflating volcanoes during periods of repose the frequent swarms and triggered earthquakes suggest the hydrothermal system is metastable