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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Introduction to Trans Australia Airlines CRM training

Trans Australia believes that its excellent accident rate record is due to a number of factors. It has a good group of standard operating procedures, and its crews are pretty well self-disciplined and adhere to those procedures. But the other thing that it believes is a factor in its safety record is that perhaps it is also due to its preparedness to be innovative, to keep up with what is going on in the rest of the world and, if it looks to have value, then to be amongst the first to try it out. Trans Australia commenced a program similar to Line Oriented Flight Training (LOFT) fairly early in 1979--that being its first windshear program-- which leads to why they are doing a course of resource management training, which we have chosen to call Aircrew Team Management (ATM). This course is detailed in another presentation.

Davidson, Jim↗
NASA NTRS1988

Preliminary results of MARECS-A measurements in Central Maryland and plans for 1988 MSS experiment in Australia

Past and future efforts are described, using L Band (1.5 GHz) satellite signals for mobile satellite system (MSS) propagation measurements. Preliminary results from the December 1987 campaign in Central Maryland with the Atlantic Ocean MARECS satellite are given. The fade level statistics from this 22 degree elevation source are consistent with helicopter measurements made along the same roads. The day to day repeatability of the fade probabilities is shown to be usually better than about 20 percent. An experiment plan is presented for measurements using the Experimental Test Satellite-V's (ETS-V's) southern beam. These measurements will be made in Australia in collaboration with Australia's National Satellite System (AUSSAT) during the July/August 1988 time-frame.

Vogel, Wolfhard J.↗
NASA NTRS1989

Effective elastic thicknesses of the lithosphere and mechanisms of isostatic compensation in Australia

The isostatic compensation of Australia is investigated using an isostatic model for the Australian lithosphere that assumes regional compensation of an elastic plate which undergoes flexure in response to surface and subsurface loading. Using the coherence between Bouguer gravity and topography and two separate gravity/topography data sets, it was found that, for the continent as a whole, loads with wavelengths above 1500 km are locally compensated. Loads with wavelengths in the range 600-1500 km are partially supported by regional stresses, and loads with wavelengths less than 600 km are almost entirely supported by the strength of the lithosphere. It was found that the predicted coherence for a flexural model of a continuous elastic plate does not provide a good fit to the observed coherence of central Australia. The disagreement between model and observations is explained.

Zuber, Maria T.↗
NASA NTRS1990

MOBILESAT: Australia's own

Australia will be introducing a dedicated Mobile Satellite Communications System following the launch of the AUSSAT-B satellites late in 1991. The Mobile Satellite System, MOBILESAT, will provide circuit switched voice/data services and packet-switched data services for land, aeronautical and maritime users. Here, an overview is given of the development program being undertaken within Australia to enable a fully commercial service to be introduced in 1992.

Wagg, Michael↗
NASA NTRS2010

Diversification in the Archean Biosphere: Insight from NanoSIMS of Microstructures in the Farrel Quartzite of Australia

The nature of early life on Earth is difficult to assess because potential Early Archean biosignatures are commonly poorly preserved. Interpretations of such materials have been contested, and abiotic or epigenetic derivations have been proposed (summarized in [1]). Yet, an understanding of Archean life is of astrobiological importance, as knowledge of early evolutionary processes on Earth could provide insight to development of life on other planets. A recently-discovered assemblage of organic microstructures in approx.3 Ga charts of the Farrel Quartzite (FQ) of Australia [2-4] includes unusual spindle-like forms and a variety of spheroids. If biogenicity and syngeneity of these forms could be substantiated, the FQ assemblage would provide a new view of Archean life. Our work uses NanoSIMS to further assess the biogenicity and syngeneity of FQ microstructures. In prior NanoSIMS studies [5-6], we gained an understanding of nano-scale elemental distributions in undisputed microfossils from the Neoproterozoic Bitter Springs Formation of Australia. Those results provide a new tool with which to evaluate poorly preserved materials that we might find in Archean sediments and possibly in extraterrestrial materials. We have applied this tool to the FQ forms.

Oehler, D. Z.↗
NASA NTRS2015

Climate Variability Drives Plankton Community Composition Changes: the 2010-2011 El Nino to La Nina Transition Around Australia

The strong La Nina of 2010-2011 provided an opportunity to investigate the ecological impacts of El Nino-Southern Oscillation on coastal plankton communities using the nine national reference stations around Australia. Based on remote sensing and across the entire Australian region 2011 (La Nina) was only modestly different from 2010 (El Nino) with the average temperature declining 0.2 percent surface chlorophyll a up 3 percent and modelled primary production down 14 percent. Other changes included a poleward shift in Prochlorococcus and Synechococcus. Along the east coast, there was a reduction in salinity, increase in nutrients, Chlorophytes and Prasinophytes (taxa with chlorophyll b, neoxanthin and prasinoxanthin). The southwest region had a rise in the proportion of 19-hexoyloxyfucoxanthin; possibly coccolithophorids in eddies of the Leeuwin Current and along the sub-tropical front. Pennate diatoms increased, Ceratium spp. decreased and Scrippsiella spp. increased in 2011. Zooplankton biomass declined significantly in 2011. There was a reduction in the abundance of Calocalanus pavo and Temora turbinata and increases in Clausocalanus farrani, Oncaea scottodicarloi and Macrosetella gracilis in 2011. The changes in the plankton community during the strong La Nina of 2011 suggest that this climatic oscillation exacerbates the tropicalization of Australia.

phytoplankton↗
NASA NTRS2023

Soil Respiration–Driven CO 2 Pulses Dominate Australia’s Flux Variability

The Australian continent contributes substantially to the year-to-year variability of the global terrestrial carbon dioxide (CO 2 ) sink. However, the scarcity of in situ observations in remote areas prevents the deciphering of processes that force the CO 2 flux variability. In this study, by examining atmospheric CO 2 measurements from satellites in the period 2009–2018, we find recurrent end-of-dry-season CO 2 pulses over the Australian continent. These pulses largely control the year-to-year variability of Australia’s CO 2 balance. They cause two to three times larger seasonal variations compared with previous top-down inversions and bottom-up estimates. The pulses occur shortly after the onset of rainfall and are driven by enhanced soil respiration preceding photosynthetic uptake in Australia’s semiarid regions. The suggested continental-scale relevance of soil-rewetting processes has substantial implications for our understanding and modeling of global climate–carbon cycle feedbacks.

Eva-Marie Metz↗
NASA NTRS2023

Spatial distributions of Tribrachidium, Rugoconites, and Obamus from the Ediacara Member (Rawnsley Quartzite), South Australia

The spatial distribution of in situ sessile organisms, including those from the fossil record, provides information about life histories, such as possible dispersal and/or settlement mechanisms, and how taxa interact with one another and their local environments. At Nilpena Ediacara National Park (NENP), South Australia, the exquisite preservation and excavation of 33 fossiliferous bedding planes from the Ediacara Member of the Rawnsley Quartzite reveals in situ communities of the Ediacara Biota. Here, the spatial distributions of three relatively common taxa, Tribrachidium, Rugoconites, and Obamus, occurring on excavated surfaces were analyzed using spatial point pattern analysis. Tribrachidium have a variable spatial distribution, implying that settlement or post-settlement conditions/preferences had an effect on populations. Rugoconites display aggregation, possibly related to their reproductive methods in combination with settlement location availability at the time of dispersal and/or settlement. Additionally, post-settlement environmental controls could have affected Rugoconites on other surfaces, resulting in lower populations and densities. Both Tribrachidium and Rugoconites also commonly occur as individuals or in low numbers on a number of beds, thus constraining possible reproductive strategies and environmental/substrate preferences. The distribution of Obamus is consistent with selective settlement, aggregating near conspecifics and on substrates of mature microbial mat. This dispersal process is the first example of substrate-selective dispersal among the Ediacara Biota, thus making Obamus similar to numerous modern sessile invertebrates with similar dispersal and settlement strategies. Resumen La distribución espacial de los organismos sésiles in situ, incluyendo los del registro fósil, brinda información sobre las historias de vida, tal como los posibles mecanismos de dispersión y/o asentamiento, y sobre cómo los taxones interactúan entre sí y entre sus entornos locales. En el Parque Nacional Nilpena Ediacara (NENP), Australia Meridional, la excelente preservación y excavación de 33 planos de lecho fosilífero del Miembro Ediacara de la Cuarcita Rawnsley revela comunidades in situ de la biota ediacárica. En este estudio analizamos las distribuciones espaciales de tres taxones relativamente comunes, Tribrachidium, Rugoconites y Obamus, que se encuentran en superficies excavadas mediante el análisis de patrones de puntos espaciales. Tribrachidium tiene una distribución espacial variable, lo que implica que las condiciones/preferencias durante o después del asentamiento tuvieron un efecto en las poblaciones. Rugoconites muestran agregación, posiblemente relacionado con sus métodos reproductivos en combinación con la disponibilidad de lugares de asentamiento en el momento de la dispersión y/o asentamiento. Además, los controles ambientales posteriormente al asentamiento podrían estar afectando a Rugoconites en otras superficies, lo que resultaría en poblaciones y densidades más bajas. Tanto Tribrachidium como Rugoconites ocurren como individuos en varios lechos, restringiendo las posibles estrategias reproductivas y las preferencias ambientales/de sustrato. La distribución de Obamus es consistente con un asentamiento selectivo, agregando cerca de sus congéneres y sobre sustratos de tapete microbiano maduro. Este proceso de dispersión es el primer ejemplo de dispersión selectiva de sustrato entre la biota ediacárica, lo que hace que Obamus sea similar a numerosos invertebrados sésiles modernos con estrategias similares de dispersión y asentamiento.

Phillip C. Boan↗
NASA NTRS2023

Elucidating the morphology and ecology of Eoandromeda octobrachiata from the Ediacaran of South Australia

Eoandromeda octobrachiata is a poorly understood Ediacaran organism, with spiral octoradial arms, found in South Australia and South China. The informal Nilpena member of the Rawnsley Quartzite, Flinders Ranges in South Australia preserves more than 200 specimens of Eoandromeda. Here we use the novel application of rotational geometric morphometrics together with palaeoenvironmental information to provide a better insight into their palaeobiology and ecology, and to address conflicting hypotheses regarding mode of life and taxonomic affinity. We find that Eoandromeda probably had a radially symmetrical shape in life, was cone shaped and had a high relief off the microbial mat. Analysis of the symmetric and asymmetric shape components showed that they deform strongly in the direction of palaeocurrent, therefore they are thought to be made of a flexible material. Almost all specimens are compressed flat. Specimens that appear to have not fully collapsed support the idea that Eoandromeda was probably cone shaped and suggest that they possibly collapsed spirally. Our shape analysis, along with observed morphological features, support a benthic rather than pelagic mode of life. Morphological and ecological inconsistencies do not fully support the hypothesis of a Ctenophora taxonomic affinity.

Tory L. Botha↗
NASA NTRS1989

Lipophilic pigments from cyanobacterial (blue-green algal) and diatom mats in Hamelin Pool, Shark Bay, Western Australia

Lipophilic pigments were examined in microbial mat communities dominated by cyanobacteria in the intertidal zone and by diatoms in the subtidal and sublittoral zones of Hamelin Pool, Shark Bay, Western Australia. These microbial mats have evolutionary significance because of their similarity to lithfied stromatolites from the Proterozoic and Early Paleozoic eras. Fucoxanthin, diatoxanthin, diadinoxanthin, beta-carotene, and chlorophylls a and c characterized the diatom mats, whereas cyanobacterial mats contained myxoxanthophyll, zeaxanthin, echinenone, beta-carotene, chlorophyll a and, in some cases, sheath pigment. The presence of bacteriochlorophyll a within the mats suggest a close association of photosynthetic bacteria with diatoms and cyanobacteria. The high carotenoids : chlorophyll a ratios (0.84-2.44 wt/wt) in the diatom mats suggest that carotenoids served a photoprotective function in this high light environment. By contrast, cyanobacterial sheath pigment may have largely supplanted the photoprotective role of carotenoids in the intertidal mats.

NASA Discipline Exobiology↗
NASA NTRS1996

Lithofacies and biofacies of mid-Paleozoic thermal spring deposits in the Drummond Basin, Queensland, Australia

The Devonian to Carboniferous sinters of the Drummond Basin, Australia, are among the oldest well established examples of fossil subaerial hot springs. Numerous subaerial and subaqueous spring deposits are known from the geological record as a result of the occurrence of economic mineral deposits in many of them. Some are reported to contain fossils, but very few have been studied by paleobiologists; they represent an untapped source of paleobiological information on the history of hydrothermal ecosystems. Such systems are of special interest, given the molecular biological evidence that thermophilic bacteria lie near the root of the tree of extant life. The Drummond Basin sinters are very closely comparable with modern examples in Yellowstone National Park and elsewhere. Thirteen microfacies are recognisable in the field, ranging from high temperature apparently abiotic geyserite through various forms of stromatolitic sinter probably of cyanobacterial origin to ambient temperature marsh deposits. Microfossils in the stromatolites are interpreted as cyanobacterial sheaths. Herbaceous lycopsids occur in the lower temperature deposits.

NASA Center ARC↗
NASA NTRS1995

Stable isotopic compositions of carbonates from the Mesoproterozoic Bangemall Group, northwestern Australia

Marine carbonate rocks from the Mesoproterozoic Bangemall Group of northwestern Australia show little deviation (+/-1.3%) in whole-rock delta 13C(carb)-values about a mean of -0.5%. This narrow range persists despite close sampling (every 10-20 m) through long sections (up to 2500 m) that are geographically widespread (up to 250 km apart), over many depositional environments (supralittoral to outer shelf), sediment sources (stromatolitic bioherms to detrital calcilutites) and rock types (pure limestones to dolomitic shales). The only major excursions from the norm seem related to unusual environmental or post-depositional processes, as they are correlated with large enrichments (to -3%) or depletions (to -16%) in 18O. Relatively heavy delta 13C-values, up to +2.5%, occur in a single bed of brecciated ferruginous dolostone at a single locality; these abnormal values may result from local evaporitic conditions. Limey and shaley nodular dolostones have delta 13C-values as low as -4.3%, probably caused by remineralization of organic matter during late and patchy dolomitization. Most notably, sharp negative excursions in delta 13C, up to -8.4%, occur in bleached kerogen-free rocks with mineral assemblages of dolomite + quartz + calcite +/- tremolite + talc, reflecting isotopic re-equilibration in thick metamorphic aureoles around dolerite intrusions. General environmental variations are minor, with delta 13C-values of peritidal facies tending to be slightly positive whereas those of subtidal facies are slightly negative. There are no strong secular trends, but subtle fluctuations within the range -2 to +l% can be correlated along the northwestern margin of the basin. This resembles the pattern seen in other Mesoproterozoic successions, but is markedly unlike the heavy background (> +5%) and extreme variations (up to l0%) in delta 13C evident in Neoproterozoic successions of similar thickness and environmental setting. Hence, in contrast to the Neoproterozoic, the global rate of organic carbon burial was probably fairly constant during deposition of the Bangemall Group, and perhaps generally during the Mesoproterozoic, as was the redox state of the atmosphere and hydrosphere.

Non-NASA Center↗
NASA NTRS1988

Distribution and diagenesis of microfossils from the lower Proterozoic Duck Creek Dolomite, Western Australia

Two distinct generations of microfossils occur in silicified carbonates from a previously undescribed locality of the Lower Proterozoic Duck Creek Dolomite, Western Australia. The earlier generation occurs in discrete organic-rich clasts and clots characterized by microquartz anhedra; it contains a variety of filamentous and coccoidal fossils in varying states of preservation. Second generation microfossils consist almost exclusively of well-preserved Gunflintia minuta filaments that drape clasts or appear to float in clear chalcedony. These filaments appear to represent an ecologically distinct assemblage that colonized a substrate containing the partially degraded remains of the first generation community. The two assemblages differ significantly in taxonomic frequency distribution from previously described Duck Creek florules. Taken together, Duck Creek microfossils exhibit a range of assemblage variability comparable to that found in other Lower Proterozoic iron formations and ferruginous carbonates. With increasing severity of post-mortem alteration, Duck Creek microfossils appear to converge morphologically on assemblages of simple microstructures described from early Archean cherts. Two new species are described: Oscillatoriopsis majuscula and O. cuboides; the former is among the largest septate filamentous fossils described from any Proterozoic formation.

NASA Discipline Number 52-30↗
NASA NTRS1987

Early Archean (3.3-billion to 3.5-billion-year-old) microfossils from Warrawoona Group, Australia

Cellularly preserved filamentous and colonial fossil microorganisms have been discovered in bedded carbonaceous cherts from the Early Archean Apex Basalt and Towers Formation of northwestern Western Australia. The cell types detected suggest that cyanobacteria, and therefore oxygen-producing photosynthesis, may have been extant as early as 3.3 billion to 3.5 billion years ago. These fossils are among the oldest now known from the geologic record; their discovery substantiates previous reports of Early Archean microfossils in Warrawoona Group strata.

Non-NASA Center↗
NASA NTRS1994

REE chemistry and Sm-Nd systematics of late Archean weathering profiles in the Fortescue Group, Western Australia

Two weathering profiles, each consisting of an upper, sericite-rich zone and a lower, chlorite-rich zone, are preserved between flows of the Mt. Roe Basalt in the Fortescue Group, Hamersley Basin, Western Australia. REE concentrations in samples from these two profiles, which originally developed ca 2,760 Ma, show large variations depending on stratigraphic position. LREE abundances and (La/Yb)N are greatest at depths of 3-6 m below the paleosurface of the Mt. Roe #1 profile and are somewhat lower in samples above this level. The LREEs reach concentrations 6-9 times greater than in the underlying basalt, and thus appear to have been mobilized downward in the paleosol and concentrated in its middle part. LREE concentrations in the #2 profile show a similar distribution but with a sharp increase in all REE concentrations within 50 cm of the paleosurface. The distinction between the REE profiles in the two paleosols may be related to the difference in the overlying material. The #1 paleosol is overlain by a few meters of sediments and then by basalt, whereas the #2 paleosol is directly overlain by basalt. The LREEs appear to have been mobilized both during chemical weathering of the parental basalt and during later lower-greenschist-facies metamorphism and metasomatism of the paleosols. Remobilization of the REEs during the regional metamorphism of the Fortescue Group is confirmed by a whole-rock Sm-Nd reference isochron of Mt. Roe #1 samples with an age of 2,151 +/- 360 Ma. Variable initial 143Nd/144Nd values of unweathered basalt samples which may represent the paleosol protolith prevents a confident determination of the magnitude of LREE mobility. Both the initial mobilization of the REEs during weathering and the metasomatic remobilization appear to have taken place under redox conditions where Ce was present dominantly as Ce3+, because Ce anomalies are not developed within the sericite zone samples regardless of concentration. Europium anomalies in the paleoweathering profile are somewhat variable and were probably modified by mobilization of Eu2+ at metamorphic conditions. In all samples, the HREEs appear to have been relatively immobile and correlate with Al, Ti, Cr, V, Zr, and Nb. Sm-Nd systematics and REE patterns of four unweathered basalt samples indicate derivation of the Mt. Roe Basalts from a heterogeneous and enriched source having epsilon Nd between -4.0 and -7.4. Initial 143Nd/144Nd values of these basalts are even lower than those reported by NELSON et al. (1992) for Fortescue Group basalts and indicate a substantial crustal component in the generation of Mt. Roe Basalts.

NASA Discipline Exobiology↗
NASA NTRS1985

Millimeter-scale variations of stable isotope abundances in carbonates from banded iron-formations in the Hamersley Group of Western Australia

Several diamond drill cores from formations within the Hamersley Group of Western Australia have been studied for evidence of short-range variations in the isotopic compositions of the carbonates. For a set of 32 adjacent microbands analyzed in a specimen from the Marra Mamba Iron Formation, carbon isotope compositions of individual microbands ranged from -2.8 to -19.8 per mil compared to PDB and oxygen isotope compositions ranged from 10.2 to 20.8 per mil compared to SMOW. A pattern of alternating abundances was present, with the average isotopic contrasts between adjacent microbands being 3.0 per mil for carbon and 3.1 per mil for oxygen. Similar results were obtained for a suite of 34 microbands (in four groups) from the Bruno's Band unit of the Mount Sylvia Formation. Difficulties were experienced in preparing samples of single microbands from the Dales Gorge Member of the Brockman Iron Formation, but overall isotopic compositions were in good agreement with values reported by previous authors. Chemical analyses showed that isotopically light carbon and oxygen were correlated with increased concentrations of iron. The preservation of these millimeter-scale variations in isotopic abundances is interpreted as inconsistent with a metamorphic origin for the isotopically light carbon in the BIF carbonates. A biological origin is favored for the correlated variations in 13C and Fe, and it is suggested that the 13C-depleted carbonates may derive either from fermentative metabolism or from anaerobic respiration. A model is presented in which these processes occur near the sediment-water interface and are coupled with an initial oxidative precipitation of the iron.

NASA Program Exobiology↗
NASA NTRS1991

Implanted 3He, 4He, and Xe in further studies of diamonds from Western Australia

In measurements of the noble gases in additional samples of diamonds from the Argyle and Ellendale lamproites in Western Australia we have failed to encounter any neon-rich stones such as showed solar-like isotopic compositions in earlier work. No neon was detected above the relatively high blank levels in our glass apparatus. White and brown diamonds showed no differences in noble gas content, nor did samples segregated by the color of long-wave UF fluorescence. The rare gas patterns in the 1.2 Ga Argyle pipe are largely consistent with implanted 3He, 4He, and fissiogenic Xe from U/Th in the matrix rock in which the diamonds have been stored for so long. These implanted species are absent in diamonds from the much younger (approximately 20 Ma) Ellendale pipe. We give implantation formulae for several models of inhomogeneously distributed U/Th. Differences in 3He content between pipe and alluvial Argyle samples are consistent with expected cosmogenic production in the latter. An expanded data base for helium and carbon isotopic data on the same samples supports a negative [4He]-delta 13C correlation seen earlier in work from our group, but if the Argyle samples, which contain light carbon, are corrected for implanted 4He, the correlation is considerably weakened. We no longer see an earlier 3He/4He-delta 13C correlation.

NASA Discipline Number 52-10↗
NASA NTRS1994

Gravity Survey of the Mt. Toondina Impact Structure South Australia

Gravity and seismic reflection data, together with geologic mapping, indicate that the Mt. Toondina feature in South Australia is best interpreted as an eroded 4-km-diameter impact structure consisting of a ring structural depression surrounding a pronounced central uplift. Beds at the center of the structure within the central uplift have been raised as much as 200 m from depth and deformed by convergent flow. Seismic reflection data indicate that deformation extends to depths of only about 800 m; at greater depths the reflectors are nearly flat lying indicating little or no deformation. Gravity data show residual anomalies of +1.0 mGal coincident with the central uplift and a -0.5 mGal low associated with the ring structural depression. Modeling of the gravity data indicates that relatively high-density material occurs within the central uplift, whereas the ring depression is filled with low-density material. The deformation at Mt. Toondina is typical of a complex impact crater; the 4-km diameter is consistent with the expected threshold size for complex craters formed in weak to moderate strength sedimentary rocks.

Mt. Toondina Australia↗