Electrical energy sources for organic synthesis on the early earth

Science.gov (United States)

Chyba, Christopher; Sagan, Carl

1991-01-01

It is pointed out that much of the contemporary origin-of-life research uses the original estimates of Miller and Urey (1959) for terrestrial energy dissipation by lightning and coronal discharges being equal to 2 x 10 to the 19th J/yr and 6 x 10 to the 19th J/yr, respectively. However, data from experiments that provide analogues to naturally-occurring lightning and coronal discharges indicate that lightning energy yields for organic synthesis (nmole/J) are about one order of magnitude higher than the coronal discharge yields. This suggests that, on early earth, organic production by lightning may have dominated that due to coronal emission. New values are recommended for lightning and coronal discharge dissipation rates on the early earth, 1 x 10 to the 18th J/yr and 5 x 10 to the 17th J/yr, respectively.

Young Sun, Early Earth and the Origins of Life Lessons for Astrobiology

CERN Document Server

Gargaud, Muriel; López-García, Purificación; Montmerle, Thierry; Pascal, Robert

2012-01-01

- How did the Sun come into existence? - How was the Earth formed? - How long has Earth been the way it is now, with its combination of oceans and continents? - How do you define “life”? - How did the first life forms emerge? - What conditions made it possible for living things to evolve? All these questions are answered in this colourful textbook addressing undergraduate students in "Origins of Life" courses and the scientifically interested public. The authors take the reader on an amazing voyage through time, beginning five thousand million years ago in a cloud of interstellar dust and ending five hundred million years ago, when the living world that we see today was finally formed. A chapter on exoplanets provides an overview of the search for planets outside the solar system, especially for habitable ones. The appendix closes the book with a glossary, a bibliography of further readings and a summary of the Origins of the Earth and life in fourteen boxes.

The role of impacts in the history of the early earth

Science.gov (United States)

French, Bevan M.

1991-01-01

The significant conclusions of a conference called 'Meteorite Impact and the Early Earth' are reported including data which support the notion that extraterrestrial impacts greatly influenced the development of the earth. The cratering of other planetary surfaces is discussed, and the energy added by meteorite impacts is characterized. The primary effects of large impacts are set forth in terms of atmospheric, oceanic, and biological considerations which suggest that the ramifications would have been significant. Contentious issues include the variation of impact rate with time in the early universe, the interpretation of the record of intense bombardment in the lunar highlands, and the effects related to alternative scenarios. Directions of future study are mentioned including the identification of terrestrial impact structures, conducting searches in the Archean, and assessing ancient impact rates.

Evolution of Earth-like Extrasolar Planetary Atmospheres: Assessing the Atmospheres and Biospheres of Early Earth Analog Planets with a Coupled Atmosphere Biogeochemical Model.

Science.gov (United States)

Gebauer, S; Grenfell, J L; Stock, J W; Lehmann, R; Godolt, M; von Paris, P; Rauer, H

2017-01-01

Understanding the evolution of Earth and potentially habitable Earth-like worlds is essential to fathom our origin in the Universe. The search for Earth-like planets in the habitable zone and investigation of their atmospheres with climate and photochemical models is a central focus in exoplanetary science. Taking the evolution of Earth as a reference for Earth-like planets, a central scientific goal is to understand what the interactions were between atmosphere, geology, and biology on early Earth. The Great Oxidation Event in Earth's history was certainly caused by their interplay, but the origin and controlling processes of this occurrence are not well understood, the study of which will require interdisciplinary, coupled models. In this work, we present results from our newly developed Coupled Atmosphere Biogeochemistry model in which atmospheric O 2 concentrations are fixed to values inferred by geological evidence. Applying a unique tool (Pathway Analysis Program), ours is the first quantitative analysis of catalytic cycles that governed O 2 in early Earth's atmosphere near the Great Oxidation Event. Complicated oxidation pathways play a key role in destroying O 2 , whereas in the upper atmosphere, most O 2 is formed abiotically via CO 2 photolysis. The O 2 bistability found by Goldblatt et al. ( 2006 ) is not observed in our calculations likely due to our detailed CH 4 oxidation scheme. We calculate increased CH 4 with increasing O 2 during the Great Oxidation Event. For a given atmospheric surface flux, different atmospheric states are possible; however, the net primary productivity of the biosphere that produces O 2 is unique. Mixing, CH 4 fluxes, ocean solubility, and mantle/crust properties strongly affect net primary productivity and surface O 2 fluxes. Regarding exoplanets, different "states" of O 2 could exist for similar biomass output. Strong geological activity could lead to false negatives for life (since our analysis suggests that reducing gases

Origin and evolution of the atmospheres of early Venus, Earth and Mars

Science.gov (United States)

Lammer, Helmut; Zerkle, Aubrey L.; Gebauer, Stefanie; Tosi, Nicola; Noack, Lena; Scherf, Manuel; Pilat-Lohinger, Elke; Güdel, Manuel; Grenfell, John Lee; Godolt, Mareike; Nikolaou, Athanasia

2018-05-01

We review the origin and evolution of the atmospheres of Earth, Venus and Mars from the time when their accreting bodies were released from the protoplanetary disk a few million years after the origin of the Sun. If the accreting planetary cores reached masses ≥ 0.5 M_Earth before the gas in the disk disappeared, primordial atmospheres consisting mainly of H_2 form around the young planetary body, contrary to late-stage planet formation, where terrestrial planets accrete material after the nebula phase of the disk. The differences between these two scenarios are explored by investigating non-radiogenic atmospheric noble gas isotope anomalies observed on the three terrestrial planets. The role of the young Sun's more efficient EUV radiation and of the plasma environment into the escape of early atmospheres is also addressed. We discuss the catastrophic outgassing of volatiles and the formation and cooling of steam atmospheres after the solidification of magma oceans and we describe the geochemical evidence for additional delivery of volatile-rich chondritic materials during the main stages of terrestrial planet formation. The evolution scenario of early Earth is then compared with the atmospheric evolution of planets where no active plate tectonics emerged like on Venus and Mars. We look at the diversity between early Earth, Venus and Mars, which is found to be related to their differing geochemical, geodynamical and geophysical conditions, including plate tectonics, crust and mantle oxidation processes and their involvement in degassing processes of secondary N_2 atmospheres. The buildup of atmospheric N_2, O_2, and the role of greenhouse gases such as CO_2 and CH_4 to counter the Faint Young Sun Paradox (FYSP), when the earliest life forms on Earth originated until the Great Oxidation Event ≈ 2.3 Gyr ago, are addressed. This review concludes with a discussion on the implications of understanding Earth's geophysical and related atmospheric evolution in relation

The (146,147)Sm-(142,143)Nd systematics of early terrestrial differentiation and the lost continents of the early Earth

Science.gov (United States)

Harper, Charles L., Jr.; Jacobsen, Stein B.

1992-01-01

The very early history of the Earth has been one of the great enduring puzzles in the history of geology. We report evidence which clearly can be described as a vestige of a beginning, because the evidence that we report cannot be interpreted in any other way except as a geochemical signal of processes active in the very early history of the Earth. The evidence itself is a very small anomaly in the abundance of SM-146. The primary aims of this study were to: (1) verify the existence of the 'lost continents' of the Hadean era; and (2) determine their mean age.

Peroxy defects in Rocks and H2O2 formation on the early Earth

Science.gov (United States)

Gray, A.; Balk, M.; Mason, P.; Freund, F.; Rothschild, L.

2013-12-01

An oxygen-rich atmosphere appears to have been a prerequisite for complex life to evolve on Earth and possibly elsewhere in the Universe. The question is still shrouded in uncertainty how free oxygen became available on the early Earth. Here we study processes of peroxy defects in silicate minerals which, upon weathering, generate mobilized electronic charge carriers resulting in oxygen formation in an initially anoxic subsurface environment. Reactive Oxygen Species (ROS) are precursors to molecular oxygen during this process. Due to their toxicity they may have strongly influenced the evolution of life. ROS are generated during hydrolysis of peroxy defects, which consist of pairs of oxygen anions. A second pathway for formation occurs during (bio) transformations of iron sulphide minerals. ROS are produced and consumed by intracellular and extracellular reactions of Fe, Mn, C, N, and S species. We propose that despite an overall reducing or neutral oxidation state of the macroenvironment and the absence of free O2 in the atmosphere, microorganisms on the early Earth had to cope with ROS in their microenvironments. They were thus under evolutionary pressure to develop enzymatic and other defenses against the potentially dangerous, even lethal effects of ROS and oxygen. We have investigated how oxygen might be released through weathering and test microorganisms in contact with rock surfaces. Our results show how early Life might have adapted to oxygen. Early microorganisms must have "trained" to detoxify ROS prior to the evolution of aerobic metabolism and oxygenic photosynthesis. A possible way out of this dilemma comes from a study of igneous and high-grade metamorphic rocks, whose minerals contain a small but significant fraction of oxygen anions in the valence state 1- , forming peroxy links of the type O3Si-OO-SiO3 [1, 2]. As water hydrolyzes the peroxy links hydrogen peroxide, H2O2, forms. Continued experimental discovery of H2O2 formation at rock

Summary of the Geocarto International Special Issue on "NASA Earth Science Satellite Data for Applications to Public Health" to be Published in Early 2014

Science.gov (United States)

Quattrochi, Dale A.

2013-01-01

At the 2011 Applied Science Public Health review held in Santa Fe, NM, it was announced that Dr. Dale Quattrochi from the NASA Marshall Space Flight Center, John Haynes, Program Manager for the Applied Sciences Public Health program at NASA Headquarters, and Sue Estes, Deputy Program Manager for the NASA Applied Sciences Public Health Program located at the Universities Space Research Association (USRA) at the National Space Science and Technology Center (NSSTC) in Huntsville, AL, would edit a special issue of the journal Geocarto International on "NASA Earth Science Satellite Data for Applications to Public Health". This issue would be focused on compiling research papers that use NASA Earth Science satellite data for applications to public health. NASA's Public Health Program concentrates on advancing the realization of societal and economic benefits from NASA Earth Science in the areas of infectious disease, emergency preparedness and response, and environmental health (e.g., air quality). This application area as a focus of the NASA Applied Sciences program, has engaged public health institutions and officials with research scientists in exploring new applications of Earth Science satellite data as an integral part of public health decision- and policy-making at the local, state and federal levels. Of interest to this special issue are papers submitted on are topics such as epidemiologic surveillance in the areas of infectious disease, environmental health, and emergency response and preparedness, national and international activities to improve skills, share data and applications, and broaden the range of users who apply Earth Science satellite data in public health decisions, or related focus areas.. This special issue has now been completed and will be published n early 2014. This talk will present an overview of the papers that will be published in this special Geocarto International issue.

Earth Observing System (EOS) Aqua Launch and Early Mission Attitude Support Experiences

Science.gov (United States)

Tracewell, D.; Glickman, J.; Hashmall, J.; Natanson, G.; Sedlak, J.

2003-01-01

The Earth Observing System (EOS) Aqua satellite was successfully launched on May 4,2002. Aqua is the second in the series of EOS satellites. EOS is part of NASA s Earth Science Enterprise Program, whose goals are to advance the scientific understanding of the Earth system. Aqua is a three-axis stabilized, Earth-pointing spacecraft in a nearly circular, sun-synchronous orbit at an altitude of 705 km. The Goddard Space Flight Center (GSFC) Flight Dynamics attitude team supported all phases of the launch and early mission. This paper presents the main results and lessons learned during this period, including: real-time attitude mode transition support, sensor calibration, onboard computer attitude validation, response to spacecraft emergencies, postlaunch attitude analyses, and anomaly resolution. In particular, Flight Dynamics support proved to be invaluable for successful Earth acquisition, fine-point mode transition, and recognition and correction of several anomalies, including support for the resolution of problems observed with the MODIS instrument.

Carbon dioxide warming of the early Earth

Science.gov (United States)

Arrhenius, G.

1997-01-01

Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

Early history of Earth's crust-mantle system inferred from hafnium isotopes in chondrites

DEFF Research Database (Denmark)

Bizzarro, Martin; Haack, Henning; Rosing, M.

2003-01-01

for the chondrite-forming event. This ¿176 value indicates that Earth's oldest minerals were derived from melts of a mantle source with a time-integrated history of depletion rather than enrichment. The depletion event must have occurred no later than 320 Myr after planetary accretion, consistent with timing......The Lu to Hf decay series has been widely used to understand the nature of Earth's early crust-mantle system. The interpretation, however, of Lu-Hf isotope data requires accurate knowledge of the radioactive decay constant of Lu (¿176), as well as bulk-Earth reference parameters. A recent...

What is the Emerging Knowledge of the Early Earth from the Oldest (>3.6 Ga) Rocks?

Science.gov (United States)

Bennett, V. C.; Nutman, A. P.

2016-12-01

Eoarchean to Hadean rocks are direct samples of early Earth chemistry and conditions and provide the ground-truth for models of early Earth formation, environments and evolution. Intensive investigations by many groups reveal rocks of this age comprise only one millionth of Earth's surface and are found in 9 areas of varying extent distributed worldwide. This record is of variable fidelity however, owing to metamorphic overprinting. The majority of the oldest rocks are high grade gneisses with protoliths from mid-crustal levels; the more rare supracrustal assemblages reflect early Earth's surface conditions and processes. First-order observations from supracrustal sequences at several localities and from 3.6 Ga to ≥3.9 Ga in age provide abundant evidence of liquid water at the Earth's surface with pillow basalts and chemical sedimentary rocks in the form of cherts, banded Fe formations and carbonates. Trace element patterns of these sedimentary rocks strongly resemble modern seawater compositions, except for the absence of redox sensitive Ce anomalies. Evidence for early life remains controversial and is mainly in the form of stable isotopic signatures of C and Fe. Our recent work from newly-discovered, exceptionally well-preserved 3.7 Ga sedimentary rocks and the deformed unconformity they rest on has provided the first evidence of Eoarchean intense weathering and shallow water sedimentary processes. Whilst the major and trace element compositions of Eoarchean gneisses have analogs in younger rocks in accord with a continuum of crust formation processes, radiogenic isotopic signatures from both long and short half-life decay schemes record an image of the Earth in transition from early differentiation processes, likely associated with planetary accretion and formation, to more modern styles. Most Eoarchean rocks possess extinct nuclide anomalies in the form of 142Nd and 182W isotopic signatures that are absent in modern terrestrial samples, and developed from

Prebiotic chemistry and atmospheric warming of early Earth by an active young Sun

Science.gov (United States)

Airapetian, V. S.; Glocer, A.; Gronoff, G.; Hébrard, E.; Danchi, W.

2016-06-01

Nitrogen is a critical ingredient of complex biological molecules. Molecular nitrogen, however, which was outgassed into the Earth’s early atmosphere, is relatively chemically inert and nitrogen fixation into more chemically reactive compounds requires high temperatures. Possible mechanisms of nitrogen fixation include lightning, atmospheric shock heating by meteorites, and solar ultraviolet radiation. Here we show that nitrogen fixation in the early terrestrial atmosphere can be explained by frequent and powerful coronal mass ejection events from the young Sun--so-called superflares. Using magnetohydrodynamic simulations constrained by Kepler Space Telescope observations, we find that successive superflare ejections produce shocks that accelerate energetic particles, which would have compressed the early Earth’s magnetosphere. The resulting extended polar cap openings provide pathways for energetic particles to penetrate into the atmosphere and, according to our atmospheric chemistry simulations, initiate reactions converting molecular nitrogen, carbon dioxide and methane to the potent greenhouse gas nitrous oxide as well as hydrogen cyanide, an essential compound for life. Furthermore, the destruction of N2, CO2 and CH4 suggests that these greenhouse gases cannot explain the stability of liquid water on the early Earth. Instead, we propose that the efficient formation of nitrous oxide could explain a warm early Earth.

Microbes, Mineral Evolution, and the Rise of Microcontinents-Origin and Coevolution of Life with Early Earth.

Science.gov (United States)

Grosch, Eugene G; Hazen, Robert M

2015-10-01

Earth is the most mineralogically diverse planet in our solar system, the direct consequence of a coevolving geosphere and biosphere. We consider the possibility that a microbial biosphere originated and thrived in the early Hadean-Archean Earth subseafloor environment, with fundamental consequences for the complex evolution and habitability of our planet. In this hypothesis paper, we explore possible venues for the origin of life and the direct consequences of microbially mediated, low-temperature hydrothermal alteration of the early oceanic lithosphere. We hypothesize that subsurface fluid-rock-microbe interactions resulted in more efficient hydration of the early oceanic crust, which in turn promoted bulk melting to produce the first evolved fragments of felsic crust. These evolved magmas most likely included sialic or tonalitic sheets, felsic volcaniclastics, and minor rhyolitic intrusions emplaced in an Iceland-type extensional setting as the earliest microcontinents. With the further development of proto-tectonic processes, these buoyant felsic crustal fragments formed the nucleus of intra-oceanic tonalite-trondhjemite-granitoid (TTG) island arcs. Thus microbes, by facilitating extensive hydrothermal alteration of the earliest oceanic crust through bioalteration, promoted mineral diversification and may have been early architects of surface environments and microcontinents on young Earth. We explore how the possible onset of subseafloor fluid-rock-microbe interactions on early Earth accelerated metavolcanic clay mineral formation, crustal melting, and subsequent metamorphic mineral evolution. We also consider environmental factors supporting this earliest step in geosphere-biosphere coevolution and the implications for habitability and mineral evolution on other rocky planets, such as Mars.

EUV-VUV photochemistry in the upper atmospheres of Titan and the early Earth

Science.gov (United States)

Imanaka, H.; Smith, M. A.

2010-12-01

Titan, the organic-rich moon of Saturn, possesses a thick atmosphere of nitrogen, globally covered with organic haze layers. The recent Cassini’s INMS and CAPS observations clearly demonstrate the importance of complex organic chemistry in the ionosphere. EUV photon radiation is the major driving energy source there. Our previous laboratory study of the EUV-VUV photolysis of N2/CH4 gas mixtures demonstrates a unique role of nitrogen photoionization in the catalytic formation of complex hydrocarbons in Titan’s upper atmosphere (Imanaka and Smith, 2007, 2009). Such EUV photochemistry could also have played important roles in the formation of complex organic molecules in the ionosphere of the early Earth. It has been suggested that the early Earth atmosphere may have contained significant amount of reduced species (CH4, H2, and CO) (Kasting, 1990, Pavlov et al., 2001, Tian et al., 2005). Recent experimental study, using photon radiation at wavelengths longer than 110 nm, demonstrates that photochemical organic haze could have been generated from N2/CO2 atmospheres with trace amounts of CH4 or H2 (Trainer et al., 2006, Dewitt et al., 2009). However, possible EUV photochemical processes in the ionosphere are not well understood. We have investigated the effect of CO2 in the possible EUV photochemical processes in simulated reduced early Earth atmospheres. The EUV-VUV photochemistry using wavelength-tunable synchrotron light between 50 - 150 nm was investigated for gas mixtures of 13CO2/CH4 (= 96.7/3.3) and N2/13CO2/CH4 (= 90/6.7/3.3). The onsets of unsaturated hydrocarbon formation were observed at wavelengths shorter than the ionization potentials of CO2 and N2, respectively. This correlation indicates that CO2 can play a similar catalytic role to N2 in the formation of heavy organic species, which implies that EUV photochemistry might have significant impact on the photochemical generation of organic haze layers in the upper atmosphere of the early Earth.

Reactive Oxygen Species on the Early Earth and Survival of Bacteria

Science.gov (United States)

Balk, Melikea; Mason, Paul; Stams, Alfons J. M.; Smidt, Hauke; Freund, Friedemann; Rothschild, Lynn

2011-01-01

An oxygen-rich atmosphere appears to have been a prerequisite for complex, multicellular life to evolve on Earth and possibly elsewhere in the Universe. However it remains unclear how free oxygen first became available on the early Earth. A potentially important, and as yet poorly constrained pathway, is the production of oxygen through the weathering of rocks and release into the near-surface environment. Reactive Oxygen Species (ROS), as precursors to molecular oxygen, are a key step in this process, and may have had a decisive impact on the evolution of life, present and past. ROS are generated from minerals in igneous rocks during hydrolysis of peroxy defects, which consist of pairs of oxygen anions oxidized to the valence state -1 and during (bio) transformations of iron sulphide minerals. ROS are produced and consumed by intracellular and extracellular reactions of Fe, Mn, C, N, and S species. We propose that, despite an overall reducing or neutral oxidation state of the macroenvironment and the absence of free O2 in the atmosphere, organisms on the early Earth had to cope with ROS in their microenvironments. They were thus under evolutionary pressure to develop enzymatic and other defences against the potentially dangerous, even lethal effects of oxygen and its derived ROS. Conversely it appears that microorganisms learned to take advantage of the enormous reactive potential and energy gain provided by nascent oxygen. We investigate how oxygen might be released through weathering. We test microorganisms in contact with rock surfaces and iron sulphides. We model bacteria such as Deionococcus radiodurans and Desulfotomaculum, Moorella and Bacillus species for their ability to grow or survive in the presence of ROS. We examine how early Life might have adapted to oxygen.

Autotrophic Ecosystems on the Early Earth

Science.gov (United States)

Schulte, M.

2003-01-01

Ophiolite sequences, sections of lower oceanic crust and upper mantle that have been thrust onto continental craton, are located in northern and central California and provide easily accessible areas that serve as good analogs for similar, more extensive areas of the early Earth. We have begun investigating and characterizing these sites in order to understand better the processes that may be responsible for the water chemistry, mineralogy and biology of similar environments on the early Earth. The geophysical and geochemical processes in these terranes provide niches for unique communities of extremeophiles and likely provide a good analog to the location that first gave rise to life on Earth. The ophiolites found in northern and central California include the Trinity, Josephine, Coast Range and Point Sal, all of which are approximately 160 million years old. Fluids from serpentinizing springs are generally alkaline with high pH and H2 contents, indicating that the mafic rock compositions control the fluid composition through water-rock reactions during relatively low-grade hydrothermal processes. There are significant amounts of primary mineralogy remaining in the rocks, meaning that substantial alteration processes are still occurring in these terranes. The general reaction for serpentinization of olivine is given by one of the authors. olivine + H2O = serpentine + brucite + magnetite + H2. We have analyzed the mineralogical composition of several rock samples collected from the Coast Range Ophiolite near Clear Lake, CA by electron microprobe. The remnant primary mineralogy is fairly urnform in composition, with an olivine composition of Fo(sub 90), and with pyroxene compositions of En(sub 90) for orthopyroxene and En(sub 49)Wo(sub 48)Fs(sub 03) for the clinopyroxene. Other primary phases observed include chromites and other spinels. Examination of petrographic thin sections reveals that serpentinization reactions have occurred in these locations. The serpentine

Hf and Nd Isotope Evidence for Production of an Incompatible Trace Element Enriched Crustal Reservoir in Early Earth (Invited)

Science.gov (United States)

Brandon, A. D.; Debaille, V.; Lapen, T. J.

2010-12-01

The final significant stage of accretion of the Earth was likely a collision between proto-Earth and a Mars sized impactor that formed the Moon. This event is thought to have produced enough thermal energy to melt all or most of the Earth, with a consequent magma ocean (MO). During subsequent cooling, the Earth would have formed its protocrust and corresponding mantle lithosphere, consisting of solidified basalt-komatiitic melt, in combination with buoyant cumulates and late stage residual melts from the MO. Relative to the convecting mantle, portions of this protolithosphere are likely to have been enriched in incompatible trace elements (ITE) in sufficient quantities to contain a significant amount of the bulk Earth’s budget for rare earth elements, U, Th, and Hf. If the protolithosphere was negatively buoyant, it may have overturned at or near the final stages of MO crystallization and a significant portion of that material may have been transported into the deep mantle where it resided and remixed into the convecting mantle over Earth history [1,2]. If the protolithosphere remained positively buoyant, its crust would have likely begun to erode from surface processes, and subsequently recycled back into the mantle over time as sediment and altered crust, once a subduction mechanism arose. The Nd and Hf isotopic compositions of Earth’s earliest rocks support the idea that an early-formed ITE-enriched reservoir was produced. The maxima in 142Nd/144Nd for 3.85 to 3.64 Ga rocks from Isua, Greenland decreases from +20 ppm to +12 ppm relative to the present day mantle value, respectively [3]. This indicates mixing of an early-formed ITE enriched reservoir back into the convecting mantle. In addition, zircons from the 3.1 Ga Jack Hills conglomerate indicate that material with an enriched 176Lu/177Hf of ~0.02 and an age of 4.4 Ga or greater was present at the Earth’s surface over the first 2 Ga of Earth history, supporting the scenario of a positively buoyant

The Geostationary Earth Radiation Budget Project.

Science.gov (United States)

Harries, J. E.; Russell, J. E.; Hanafin, J. A.; Brindley, H.; Futyan, J.; Rufus, J.; Kellock, S.; Matthews, G.; Wrigley, R.; Last, A.; Mueller, J.; Mossavati, R.; Ashmall, J.; Sawyer, E.; Parker, D.; Caldwell, M.; Allan, P. M.; Smith, A.; Bates, M. J.; Coan, B.; Stewart, B. C.; Lepine, D. R.; Cornwall, L. A.; Corney, D. R.; Ricketts, M. J.; Drummond, D.; Smart, D.; Cutler, R.; Dewitte, S.; Clerbaux, N.; Gonzalez, L.; Ipe, A.; Bertrand, C.; Joukoff, A.; Crommelynck, D.; Nelms, N.; Llewellyn-Jones, D. T.; Butcher, G.; Smith, G. L.; Szewczyk, Z. P.; Mlynczak, P. E.; Slingo, A.; Allan, R. P.; Ringer, M. A.

2005-07-01

This paper reports on a new satellite sensor, the Geostationary Earth Radiation Budget (GERB) experiment. GERB is designed to make the first measurements of the Earth's radiation budget from geostationary orbit. Measurements at high absolute accuracy of the reflected sunlight from the Earth, and the thermal radiation emitted by the Earth are made every 15 min, with a spatial resolution at the subsatellite point of 44.6 km (north south) by 39.3 km (east west). With knowledge of the incoming solar constant, this gives the primary forcing and response components of the top-of-atmosphere radiation. The first GERB instrument is an instrument of opportunity on Meteosat-8, a new spin-stabilized spacecraft platform also carrying the Spinning Enhanced Visible and Infrared (SEVIRI) sensor, which is currently positioned over the equator at 3.5°W. This overview of the project includes a description of the instrument design and its preflight and in-flight calibration. An evaluation of the instrument performance after its first year in orbit, including comparisons with data from the Clouds and the Earth's Radiant Energy System (CERES) satellite sensors and with output from numerical models, are also presented. After a brief summary of the data processing system and data products, some of the scientific studies that are being undertaken using these early data are described. This marks the beginning of a decade or more of observations from GERB, as subsequent models will fly on each of the four Meteosat Second Generation satellites.

Impact bombardmnet and its role in proto-continental growth on the early Earth

International Nuclear Information System (INIS)

Grieve, R.A.F.

1980-01-01

There is evidence that during 4.6-3.9 Ga the Earth experienced a period of intense bombardment similar to that recorded on the Moon. From cratering mechanics and by comparison with more recent terrestrial impact structures the effects of large impact structures, D >= 100 km, have been modelled for an early terrestrial proto-crust with an assumed thickness of 15 km. The direct effects were analogous to those on the Moon: the formation of multi-ring basins with a topography of approximately 3 km, the uplift of deep-seated material to the surface, the fracturing of the crustal column and the generation of surface impact lithologies. However, unlike the Moon, the highly active nature of the Earth resulted in more long-lived indirect effects: impact-induced volcanism due to distortion of the geothermal gradient by uplift and the addition of post-shock heat, intra-basin sedimentation by volcaniclastics and reworked impact lithologies and ultimately subsidence of the basin due to loading by volcanic and sedimentary products. Very large basins, D > 1000 km, excavated the local lithosphere and produced the equivalent of mantle plumes below the impact sites. These conclusions are incorporated into a model of early crustal evolution of the Earth in which the net effect of large impact events was to localize and accelerate endogenic activity. (Auth.)

Earth's early O2 cycle suppressed by primitive continents

Science.gov (United States)

Smit, Matthijs A.; Mezger, Klaus

2017-10-01

Free oxygen began to accumulate in Earth's surface environments between 3.0 and 2.4 billion years ago. Links between oxygenation and changes in the composition of continental crust during this time are suspected, but have been difficult to demonstrate. Here we constrain the average composition of the exposed continental crust since 3.7 billion years ago by compiling records of the Cr/U ratio of terrigenous sediments. The resulting record is consistent with a predominantly mafic crust prior to 3.0 billion years ago, followed by a 500- to 700-million-year transition to a crust of modern andesitic composition. Olivine and other Mg-rich minerals in the mafic Archaean crust formed serpentine minerals upon hydration, continuously releasing O2-scavenging agents such as dihydrogen, hydrogen sulfide and methane to the environment. Temporally, the decline in mafic crust capable of such process coincides with the first accumulation of O2 in the oceans, and subsequently the atmosphere. We therefore suggest that Earth's early O2 cycle was ultimately limited by the composition of the exposed upper crust, and remained underdeveloped until modern andesitic continents emerged.

Summary the race to reinvent energy and stop global warming

CERN Document Server

2013-01-01

Complete summary of Fred Krupp and Miriam Horn's book: ""Earth: The Sequel: The Race to Reinvent Energy and Stop Global Warming"". This summary of the ideas from Fred Krupp and Miriam Horn's book ""Earth: The Sequel"" explains how capitalism, as the most powerful economic force in the world, is the only engine of change that has the strength to stop global warming. In their book, the authors demonstrate how this can be achieved by installing a cap-and-trade initiative, providing genuine economic incentives for companies and reducing their carbon footprint. This summary explains their theory in

Early results from Magsat. [studies of near-earth magnetic fields

Science.gov (United States)

Langel, R. A.; Estes, R. H.; Mayhew, M. A.

1981-01-01

Papers presented at the May 27, 1981 meeting of the American Geophysical Union concerning early results from the Magsat satellite program, which was designed to study the near-earth magnetic fields originating in the core and lithosphere, are discussed. The satellite was launched on October 30, 1979 into a sun-synchronous (twilight) orbit, and re-entered the atmosphere on June 11, 1980. Instruments carried included a cesium vapor magnetometer to measure field magnitudes, a fluxgate magnetometer to measure field components and an optical system to measure fluxgate magnetometer orientation. Early results concerned spherical harmonic models, fields due to ionospheric and magnetospheric currents, the identification and interpretation of fields from lithospheric sources. The preliminary results confirm the possibility of separating the measured field into core, crustal and external components, and represent significant developments in analytical techniques in main-field modelling and the physics of the field sources.

Petrochronology in constraining early Archean Earth processes and environments: Barberton greenstone belt, South Africa

Science.gov (United States)

Grosch, Eugene

2017-04-01

Analytical and petrological software developments over the past decade have seen rapid innovation in high-spatial resolution petrological techniques, for example, laser-ablation ICP-MS, secondary ion microprobe (SIMS, nano-SIMS), thermodynamic modelling and electron microprobe microscale mapping techniques (e.g. XMapTools). This presentation will focus on the application of petrochronology to ca. 3.55 to 3.33 billion-year-old metavolcanic and sedimentary rocks of the Onverwacht Group, shedding light on the earliest geologic evolution of the Paleoarchean Barberton greenstone belt (BGB) of South Africa. The field, scientific drilling and petrological research conducted over the past 8 years, aims to illustrate how: (a) LA-ICP-MS and SIMS U-Pb detrital zircon geochronology has helped identify the earliest tectono-sedimentary basin and sediment sources in the BGB, as well as reconstructing geodynamic processes as early as ca. 3.432 billion-years ago; (b) in-situ SIMS multiple sulphur isotope analysis of sulphides across various early Archean rock units help to reconstruct atmospheric, surface and subsurface environments on early Archean Earth and (c) the earliest candidate textural traces for subsurface microbial life can be investigated by in-situ LA-ICP-MS U-Pb dating of titanite, micro-XANES Fe-speciation analysis and metamorphic microscale mapping. Collectively, petrochronology combined with high-resolution field mapping studies, is a powerful multi-disciplinary approach towards deciphering petrogenetic and geodynamic processes preserved in the Paleoarchean Barberton greenstone belt of South Africa, with implications for early Archean Earth evolution.

Cometary delivery of organic molecules to the early earth

Science.gov (United States)

Chyba, Christopher F.; Thomas, Paul J.; Sagan, Carl; Brookshaw, Leigh

1990-01-01

It has long been speculated that earth accreted prebiotic organic molecules important for the origins of life from impacts of carbonaceous asteroids and comets during the period of heavy bombardment 4.5 x 10 to the 9th to 3.8 x 10 to the 9th years ago. A comprehensive treatment of comet-asteroid interaction with the atmosphere, surface impact, and resulting organic pyrolysis demonstrates that organics will not survive impacts at velocities greater than about 10 kilometers per second and that even comets and asteroids as small as 100 meters in radius cannot be aerobraked to below this velocity in 1-bar atmospheres. However, for plausible dense (10-bar carbon dioxide) early atmospheres, it is found that 4.5 x 10 to the 9th years ago earth was accreting intact cometary organics at a rate of at least about 10 to the 6th to 10 to the 7th kilograms per year, a flux that thereafter declined with a half-life of about 10 to the 8th years. These results may be put in context by comparison with terrestrial oceanic and total biomasses, about 3 x 10 to the 12th kilograms and about 6 x 10 to the 14th kilograms, respectively.

Challenges to modeling the Sun-Earth System: A Workshop Summary

Science.gov (United States)

Spann, James F.

2006-01-01

This special issue of the Journal of' Atmospheric and Solar-Terrestrial Physics is a compilation of 23 papers presented at The 2004 Huntsville Modeling Workshop: Challenges to Modeling thc San-Earth System held in Huntsville, AB on October 18-22, 2004. The title of the workshop appropriately captures the theme of what was presented and discussed by the 120 participants. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA living with a star (LWS) programs. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales inn time and space. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress

Photosynthetic microbial mats today, on early Earth, (and on early Mars?)

Science.gov (United States)

Des Marais, D. J.

2008-05-01

extensive, highly productive biosphere? Perhaps the substantial decline in geothermal activity during the Archean created a driver for the development of oxygenic photosynthesis. Can we further document the Archean biosphere? The pre-3.5 Ga crust of Mars records evidence of surface water and is far better preserved than the early crust of Earth. Perhaps Mars exploration will extend our understanding of emerging biospheres to even earlier periods.

Wood fuel from early thinning and plantation cleaning. Summary of an international review

International Nuclear Information System (INIS)

Puttock, D.

1998-01-01

This paper summaries the results of an international of wood fuel from early thinning and plantation cleaning. The economic and biological benefits from early thinning have been well documented. However, removing forest biomass during early stages of stand development from sites which are low in one or more nutrients may contribute a loss of nutrients and organic matter. Depending on the pre-thinning density and the thinning intensity, the potential yield of wood fuel from early thinning may be as much as 79 dry tons per hectare. Thus, wood fuel from the thinnings could be an important source of revenue to forest owners and would contribute to domestic energy requirements. Motor-manual felling predominates in early thinning, mainly due to the lack of appropriate technology for thinning small trees. However, the productivity of motor-manual felling is greatly affected by the initial stand density and declines dramatically at densities greater than 10 000 stems per ha. Under these conditions, purpose-built wood fuel harvesters with small-tree harvesting capability offer the greatest potential for increasing felling productivity and reducing the cost of wood fuel. The cost of wood fuel from early thinnings varies widely between countries from USD 25.00 - 87.50 per dry ton depending on stand conditions, harvesting system, transport distance, domestic tax rates, and stumpage prices. At the low end of this range, wood fuel chips from early thinning are competitive with wood fuel produced from mill waste, the residues from clearfell operations, or from later thinnings

International strategic minerals inventory summary report; rare-earth oxides

Science.gov (United States)

Jackson, W.D.; Christiansen, Grey

1993-01-01

Bastnaesite, monazite, and xenotime are currently the most important rare-earth minerals. Bastnaesite occurs as a primary mineral in carbonatites. Monazite and xenotime also can be found in primary deposits but are recovered principally from heavy-mineral placers that are mined for titanium or tin. Each of these minerals has a different composition of the 15 rare-earth elements. World resources of economically exploitable rare-earth oxides (REO) are estimated at 93.4 million metric tons in place, composed of 93 percent in primary deposits and 7 percent in placers. The average mineral composition is 83 percent bastnaesite, 13 percent monazite, and 4 percent of 10 other minerals. Annual global production is about 67,000 metric tons of which 41 percent is from placers and 59 percent is from primary deposits; mining methods consist of open pits (94 percent) and dredging (6 percent). This output could be doubled if the operations that do not currently recover rare earths would do so. Resources are more than sufficient to meet the demand for the predictable future. About 52 percent of the world's REO resources are located in China. Ranking of other countries is as follows: Namibia (22 percent), the United States (15 percent), Australia (6 percent), and India (3 percent); the remainder is in several other countries. Conversely, 38 percent of the production is in China, 33 percent in the United States, 12 percent in Australia, and 5 percent each in Malaysia and India. Several other countries, including Brazil, Canada, South Africa, Sri Lanka, and Thailand, make up the remainder. Markets for rare earths are mainly in the metallurgical, magnet, ceramic, electronic, chemical, and optical industries. Rare earths improve the physical and rolling properties of iron and steel and add corrosion resistance and strength to structural members at high temperatures. Samarium and neodymium are used in lightweight, powerful magnets for electric motors. Cerium and yttrium increase the

A review of noble gas geochemistry in relation to early Earth history

Science.gov (United States)

Kurz, M. D.

1985-01-01

One of the most fundamental noble gas constraints on early Earth history is derived from isotopic differences in (129)Xe/(130)Xe between various terrestrial materials. The short half life (17 m.y.) of extinct (129I, parent of (129)Xe, means that these differences must have been produced within the first 100 m.y. after terrestrial accretion. The identification of large anomalies in (129)Xe/(130)Xe in mid ocean ridge basalts (MORB), with respect to atmospheric xenon, suggests that the atmosphere and upper mantle have remained separate since that time. This alone is a very strong argument for early catastrophic degassing, which would be consistent with an early fractionation resulting in core formation. However, noble gas isotopic systematics of oceanic basalts show that the mantle cannot necessarily be regarded as a homogeneous system, since there are significant variations in (3)He/(4)He, (40)Ar/(36)Ar, and (129)Xe/(130)Xe. Therefore, the early degassing cannot be considered to have acted on the whole mantle. The specific mechanisms of degassing, in particular the thickness and growth of the early crust, is an important variable in understanding present day noble gas inventories. Another constraint can be obtained from rocks that are thought to be derived from near the lithosphere asthenosphere boundary: ultramafic xenoliths.

Optical MEMS for earth observation payloads

Science.gov (United States)

Rodrigues, B.; Lobb, D. R.; Freire, M.

2017-11-01

An ESA study has been taken by Lusospace Ltd and Surrey Satellite Techonoly Ltd (SSTL) into the use of optical Micro Eletro-Mechanical Systems (MEMS) for earth Observation. A review and analysis was undertaken of the Micro-Optical Electro-Mechanical Systems (MOEMS) available in the market with potential application in systems for Earth Observation. A summary of this review will be presented. Following the review two space-instrument design concepts were selected for more detailed analysis. The first was the use of a MEMS device to remove cloud from Earth images. The concept is potentially of interest for any mission using imaging spectrometers. A spectrometer concept was selected and detailed design aspects and benefits evaluated. The second concept developed uses MEMS devices to control the width of entrance slits of spectrometers, to provide variable spectral resolution. This paper will present a summary of the results of the study.

Earth's earliest biosphere: Its origin and evolution

International Nuclear Information System (INIS)

Schopf, J.W.

1983-01-01

Some of the subjects discussed are related to the early biogeologic history, the nature of the earth prior to the oldest known rock record, the early earth and the Archean rock record, the prebiotic organic syntheses and the origin of life, Precambrian organic geochemistry, the biochemical evolution of anaerobic energy conversion, the isotopic inferences of ancient biochemistries, Archean stromatolites providing evidence of the earth's earliest benthos, Archean microfossils, the geologic evolution of the Archean-Early Proterozoic earth, and the environmental evolution of the Archean-Early Proterozoic earth. Other topics examined are concerned with geochemical evidence bearing on the origin of aerobiosis, biological and biochemical effects of the development of an aerobic environment, Early Proterozoic microfossils, the evolution of earth's earliest ecosystems, and geographic and geologic data for processed rock samples. Attention is given to a processing procedure for abiotic samples and calculation of model atmospheric compositions, and procedures of organic geochemical analysis

The Pale Orange Dot: Spectral Effects of a Hazy Early Earth

Science.gov (United States)

Arney, G. N.; Meadows, V. S.; Domagal-Goldman, S. D.; Claire, M.; Schwieterman, E.

2014-12-01

Increasing evidence suggests Archean Earth had a photochemical hydrocarbon haze similar to Titan's (Zerkle et al. 2012), with important climate implications (Pavlov et al. 2001, Trainer et al. 2006, Haqq-Misra et al. 2008, Domagal-Goldman et al. 2008, Wolf and Toon 2012). Observations also suggest hazy exoplanets are common (Sing et al. 2011, Kreidberg et al 2014), so hazy planet spectra will be relevant to future exoplanet spectral characterization missions. Here, we consider the implications of hydrocarbon aerosols on the spectrum of Archean Earth, examining the effect of a haze layer on the detectability of spectral features from putative biosignatures and the Rayleigh scattering slope. We also examine haze's impact on the spectral energy distribution at the planetary surface, which may be important to the co-evolution of life with its environment. Because the atmospheric pressure and haze particle composition of the Archean Earth are poorly constrained, we test the impact of atmospheric pressure and particle density on haze formation. Our study uses a modified version of the 1-D photochemical code developed originally by Kasting et al. (1979) to generate a fractal haze in the model Archean atmosphere. The 1-D line-by-line fully multiple scattering Spectral Mapping Atmospheric Radiative Transfer Model (SMART) (Meadows and Crisp 1996) is then used to generate synthetic spectra of early Earth with haze. We find (Fig 1) that haze scattering significantly depletes the radiation at short wavelengths, strongly affecting the spectral region of the Rayleigh slope, a broadband change in spectral shape detectable at low spectral resolution. At the surface, the spectral energy distribution is shifted towards longer wavelengths, which may be important to photosynthetic life. Thus, the haze may have significant effects on biology, which in turn produces the methane that leads to haze formation, creating feedback loops between biology and the planet.

Earth observations from space: History, promise, and reality. Executive summary

Science.gov (United States)

1995-01-01

In this report the Committee on Earth Studies (CES), a standing committee of the Space Studies Board (SSB) within the National Research Council (NRC), reviews the recent history (nominally from 1981 to 1995) of the U.S. earth observations programs that serve civilian needs. The principal observations programs examined are those of NASA and the National Oceanic and Atmospheric Administration (NOAA). The Air Force' s Defense Meteorological Satellite Program (DMSP) is discussed, but only from the perspective of its relationship to civil needs and the planned merger with the NOAA polar-orbiting system. The report also reviews the interfaces between the earth observations satellite programs and the major national and international environmental monitoring and research programs. The monitoring and research programs discussed are the U.S. Global Change Research Program (USGCRP), the International Geosphere-Biosphere Program (IGBP), the World Climate Research Program (WCRP), related international scientific campaigns, and operational programs for the sharing and application of environmental data. The purpose of this report is to provide a broad historical review and commentary based on the views of the CES members, with particular emphasis on tracing the lengthy record of advisory committee recommendations. Any individual topic could be the subject of an extended report in its own right. Indeed, extensive further reviews are already under way to that end. If the CES has succeeded in the task it has undertaken. This report will serve as a useful starting point for any such more intensive study. The report is divided into eight chapters: ( I ) an introduction, (2) the evolution of the MTPE, (3) its relationship to the USGCRP, (4) applications of earth observations data, (5) the role that smaller satellites can play in research and operational remote sensing, (6) earth system modeling and information systems, (7) a number of associated activities that contribute to the MTPE

Raising awareness for research on earth walls, and earth scientific aspects

Science.gov (United States)

van den Ancker, Hanneke; Jungerius, Pieter Dirk; Baas, Henk; Groenewoudt, Bert; Peen, Charlotte

2013-04-01

A conference to raise awareness In the Netherlands, little research on earth walls has been done. To improve attention for earth walls, a number of organisations, including Geoheritage NL, organized a conference at the RCE, the Cultural Heritage Agency of the Netherlands. The conference* presented a state-of-the-art of research done. The book with the presentations, and extra case studies added, was published in December 2012. The book concludes with a research action list, including earth science research, and can be downloaded freely from the internet. It has English summaries. The earth science aspects Historical earth walls do not only add cultural value to a landscape, but also geodiversity value. Apart from geomorphological aspects, the walls contain information about past land- and climate conditions: - They cover up a former topography, a past landscape. A relevant source of scientific information where lands are levelled, as is the case in many parts of The Netherlands; - The soil formation under the earth wall is a reference soil. The soil formation in the top of the wall gives insight in the rate of soil formation in relationship with the age and parent material of the wall; - The soil profiles of different age have ecological significance. Older walls with a more pronounced soil formation often hold forest flora that has disappeared from the surrounding environment, such as historical bush or tree species, autogenetic DNA material or a specific soil fauna; - The materials in the earth walls tell about the process of wall-building. Paleosols and sedimentary structures in the earth walls, in the gullies and colluvial fans along the walls contain information about past land management and climate. - The eroded appearance of the earth walls is part of their history, and contain information about past management and land conditions, has ecological relevance, for example for insects, and is often visually more interesting. Insight in the rates of erosion are

Definition of technology development missions for early Space Station satellite servicing. Volume 1: Executive summary

Science.gov (United States)

1984-01-01

The Executive Summary volume 1, includes an overview of both phases of the Definition of Technology Development Missions for Early Space Station Satellite Servicing. The primary purpose of Phase 1 of the Marshall Space Flight Center (MSFC) Satellite Servicing Phase 1 study was to establish requirements for demonstrating the capability of performing satellite servicing activities on a permanently manned Space Station in the early 1990s. The scope of Phase 1 included TDM definition, outlining of servicing objectives, derivation of initial Space Station servicing support requirements, and generation of the associated programmatic schedules and cost. The purpose of phase 2 of the satellite servicing study was to expand and refine the overall understanding of how best to use the manned space station as a test bed for demonstration of satellite servicing capabilities.

Growing and Supporting the Student and Early Career Pipeline in Earth and Space Sciences - A Spotlight on New AGU Initiatives

Science.gov (United States)

Hankin, E. R.; Williams, B. M.; Asher, P. M.; Furukawa, H.; Holm Adamec, B.; Lee, M.; Cooper, P.

2015-12-01

The American Geophysical Union (AGU) is home to more than 60,000 scientists from 139 countries. Included in this membership are approximately 20,000 (34%) student and early career members. Many well-established programs within AGU provide a dynamic forum for Earth and Space scientists to advance research, collaborate across disciplines, and communicate the importance and impact of science to society regardless of career stage—programs such as AGU publications, scientific meetings and conferences, honors and recognition, and other educational and scientific forums. Additionally, many AGU program initiatives focusing specifically on supporting student and early career scientists and the global talent pool pipeline ones are actively underway. These include both new and long-standing programs. This presentation will describe (1) the overall demographics and needs in Earth and Space sciences, and (2) AGU's coordinated series of programs designed to help attract, retain and support student and early career scientists—with an emphasis on new programmatic activities and initiatives targeting improved diversity. Included in this presentation are a description of the AGU BrightSTaRS Program, the AGU Berkner Program for international students, a newly established AGU Student & Early Career Conference, the AGU Virtual Poster Showcase initiative, the AGU Meeting Mentor program, and GeoLEAD—an umbrella program being jointly built by a coalition of societies to help address Earth and space sciences talent pool needs.

Abiotic synthesis of porphyrins and other oligopyrroles on the early Earth and Earth-like planets

Science.gov (United States)

Fox, S.; Strasdeit, H.

2013-09-01

It is generally accepted that abiotically formed amino acids existed on Earth in the late Hadean and early Archean (four billion years ago). They were mainly dissolved in a salty primordial ocean. At that time, volcanic islands were much more abundant than today. It is therefore reasonable to assume that, at hot volcanic coasts, amino acids could have been thermally transformed into other organic molecules. Based on this scenario, we conducted laboratory experiments that simulated the interaction between amino acid-containing sea water and hot lava. In these experiments, a large number of different volatile products were formed, among them pyrroles. It was also possible to obtain porphyrins and other oligopyrroles from pyrroles under simulated conditions of primordial volcanic islands. All experiments were conducted under plausible prebiotic conditions. Our results reveal an abiotic pathway to possible precursors of oligopyrrole-type biomolecules, such as heme and chlorophylls.

Biomarkers as tracers for life on early earth and Mars

Science.gov (United States)

Simoneit, B. R.; Summons, R. E.; Jahnke, L. L.

1998-01-01

Biomarkers in geological samples are products derived from biochemical (natural product) precursors by reductive and oxidative processes (e.g., cholestanes from cholesterol). Generally, lipids, pigments and biomembranes are preserved best over longer geological times and labile compounds such as amino acids, sugars, etc. are useful biomarkers for recent times. Thus, the detailed characterization of biomarker compositions permits the assessment of the major contributing species of extinct and/or extant life. In the case of the early Earth, work has progressed to elucidate molecular structure and carbon isotropic signals preserved in ancient sedimentary rocks. In addition, the combination of bacterial biochemistry with the organic geochemistry of contemporary and ancient hydrothermal ecosystems permits the modeling of the nature, behavior and preservation potential of primitive microbial communities. This approach uses combined molecular and isotopic analyses to characterize lipids produced by cultured bacteria (representative of ancient strains) and to test a variety of culture conditions which affect their biosynthesis. On considering Mars, the biomarkers from lipids and biopolymers would be expected to be preserved best if life flourished there during its early history (3.5-4 x 10(9) yr ago). Both oxidized and reduced products would be expected. This is based on the inferred occurrence of hydrothermal activity during that time with the concomitant preservation of biochemically-derived organic matter. Both known biomarkers (i.e., as elucidated for early terrestrial samples and for primitive terrestrial microbiota) and novel, potentially unknown compounds should be characterized.

Early non-destructive biofouling detection in spiral wound RO Membranes using a mobile earth's field NMR

KAUST Repository

Fridjonsson, E.O.

2015-04-20

We demonstrate the use of Earth\\'s field (EF) Nuclear Magnetic Resonance (NMR) to provide early non-destructive detection of active biofouling of a commercial spiral wound reverse osmosis (RO) membrane module. The RO membrane module was actively biofouled to different extents, by the addition of biodegradable nutrients to the feed stream, as revealed by a subtle feed-channel pressure drop increase. Easily accessible EF NMR parameters (signal relaxation parameters T1, T2 and the total NMR signal modified to be sensitive to stagnant fluid only) were measured and analysed in terms of their ability to detect the onset of biofouling. The EF NMR showed that fouling near the membrane module entrance significantly distorted the flow field through the whole membrane module. The total NMR signal is shown to be suitable for non-destructive early biofouling detection of spiral wound membrane modules, it was readily deployed at high (operational) flow rates, was particularly sensitive to flow field changes due to biofouling and could be deployed at any position along the membrane module axis. In addition to providing early fouling detection, the mobile EF NMR apparatus could also be used to (i) evaluate the production process of spiral wound membrane modules, and (ii) provide an in-situ determination of module cleaning process efficiency.

The Early Years: The Earth-Sun System

Science.gov (United States)

Ashbrook, Peggy

2015-01-01

We all experience firsthand many of the phenomena caused by Earth's Place in the Universe (Next Generation Science Standard 5-ESS1; NGSS Lead States 2013) and the relative motion of the Earth, Sun, and Moon. Young children can investigate phenomena such as changes in times of sunrise and sunset (number of daylight hours), Moon phases, seasonal…

Summaries of FY 1995 geosciences research

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

The summaries in this document, prepared by the investigators, describe the scope of the individual programs. The Geosciences Research Program includes research in geophysics, geochemistry, resource evaluation, solar-terrestrial interactions, and their subdivisions including earth dynamics, properties of earth materials, rock mechanics, underground imaging, rock-fluid interactions, continental scientific drilling, geochemical transport, solar/atmospheric physics, and modeling, with emphasis on the interdisciplinary areas. All such research is related either direct or indirect to the Department of Energy`s long-range technological needs.

Earth observation from the manned low Earth orbit platforms

Science.gov (United States)

Guo, Huadong; Dou, Changyong; Zhang, Xiaodong; Han, Chunming; Yue, Xijuan

2016-05-01

The manned low Earth orbit platforms (MLEOPs), e.g., the U.S. and Russia's human space vehicles, the International Space Station (ISS) and Chinese Tiangong-1 experimental space laboratory not only provide laboratories for scientific experiments in a wide range of disciplines, but also serve as exceptional platforms for remote observation of the Earth, astronomical objects and space environment. As the early orbiting platforms, the MLEOPs provide humans with revolutionary accessibility to the regions on Earth never seen before. Earth observation from MLEOPs began in early 1960s, as a part of manned space flight programs, and will continue with the ISS and upcoming Chinese Space Station. Through a series of flight missions, various and a large amount of Earth observing datasets have been acquired using handheld cameras by crewmembers as well as automated sophisticated sensors onboard these space vehicles. Utilizing these datasets many researches have been conducted, demonstrating the importance and uniqueness of studying Earth from a vantage point of MLEOPs. For example, the first, near-global scale digital elevation model (DEM) was developed from data obtained during the shuttle radar topography mission (SRTM). This review intends to provide an overview of Earth observations from MLEOPs and present applications conducted by the datasets collected by these missions. As the ISS is the most typical representative of MLEOPs, an introduction to it, including orbital characteristics, payload accommodations, and current and proposed sensors, is emphasized. The advantages and challenges of Earth observation from MLEOPs, using the ISS as an example, is also addressed. At last, a conclusive note is drawn.

The Biological Potential of Mars, the Early Earth, and Europa

Science.gov (United States)

Jakosky, B. M.; Shock, E. L.

1998-09-01

The potential biomass that could have existed on Mars is constrained by the total amount of energy available to construct it. From an inventory of the available geochemical sources of energy, we estimate that, from the time of the onset of the visible geologic record 4 b.y. ago to the present, as much as 20 g/cm2 of biota could have been constructed. This is the same amount that could have been constructed from similar sources on the early Earth in only 100 m.y. This indicates that there likely was sufficient energy available to support an origin of life on Mars, but not sufficient energy to create a ubiquitous and lush biosphere. Similar calculations for Europa suggest that even less geochemical energy would have been available there.

EarthServer: a Summary of Achievements in Technology, Services, and Standards

Science.gov (United States)

Baumann, Peter

2015-04-01

Big Data in the Earth sciences, the Tera- to Exabyte archives, mostly are made up from coverage data, according to ISO and OGC defined as the digital representation of some space-time varying phenomenon. Common examples include 1-D sensor timeseries, 2-D remote sensing imagery, 3D x/y/t image timese ries and x/y/z geology data, and 4-D x/y/z/t atmosphere and ocean data. Analytics on such data requires on-demand processing of sometimes significant complexity, such as getting the Fourier transform of satellite images. As network bandwidth limits prohibit transfer of such Big Data it is indispensable to devise protocols allowing clients to task flexible and fast processing on the server. The transatlantic EarthServer initiative, running from 2011 through 2014, has united 11 partners to establish Big Earth Data Analytics. A key ingredient has been flexibility for users to ask whatever they want, not impeded and complicated by system internals. The EarthServer answer to this is to use high-level, standards-based query languages which unify data and metadata search in a simple, yet powerful way. A second key ingredient is scalability. Without any doubt, scalability ultimately can only be achieved through parallelization. In the past, parallelizing cod e has been done at compile time and usually with manual intervention. The EarthServer approach is to perform a samentic-based dynamic distribution of queries fragments based on networks optimization and further criteria. The EarthServer platform is comprised by rasdaman, the pioneer and leading Array DBMS built for any-size multi-dimensional raster data being extended with support for irregular grids and general meshes; in-situ retrieval (evaluation of database queries on existing archive structures, avoiding data import and, hence, duplication); the aforementioned distributed query processing. Additionally, Web clients for multi-dimensional data visualization are being established. Client/server interfaces are strictly

Contributions to the rare earths to science and technology

International Nuclear Information System (INIS)

Spedding, F.H.

1975-01-01

This is a brief summary of some areas of science where the rare earths have already played an important role and of other areas where they are almost certain to be helpful. The discovery, abundance, separation, and properties of rare earths are discussed. It is pointed out that the rare earths comprise almost one-fourth of the known metals, and their alloys a third of the possible alloys

Earth Sciences Division annual report 1989

Energy Technology Data Exchange (ETDEWEB)

1990-06-01

This Annual Report presents summaries of selected representative research activities from Lawrence Berkeley Laboratory grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrology, Geology and Geochemistry, and Geophysics and Geomechanics. We are proud to be able to bring you this report, which we hope will convey not only a description of the Division's scientific activities but also a sense of the enthusiasm and excitement present today in the Earth Sciences.

Indexing, screening, coding and cataloging of earth resources aircraft mission data

Science.gov (United States)

1977-01-01

Tasks completed are as follows: (1) preparation of large Area Crop Inventory experiment for data base entry;(2) preparation of Earth Observations Aircraft Flight summary reports for publication; (3) updating of the aircraft mission index coverage map and Ames aircraft flight map; (4) Prepared of Earth Observation Helicopter Flight reports for publication; and (5) indexing of LANDSAT imagery. (6) formulation of phase 3 biowindows 1, 2, 3, and 4 listings by country, footprint, and acqusition dates; (7) preparation of flight summary reports; and (8) preparation of an Alaska state index coverage map.

Comparison of CT perfusion summary maps to early diffusion-weighted images in suspected acute middle cerebral artery stroke

Energy Technology Data Exchange (ETDEWEB)

Benson, John; Payabvash, Seyedmehdi [Hennepin County and University of Minnesota Medical Centers, Department of Radiology, Minneapolis, MN (United States); Salazar, Pascal [Vital Images, A Division of Toshiba Medical, Minnetonka, MN (United States); Jagadeesan, Bharathi; Palmer, Christopher S.; Truwit, Charles L. [Hennepin County and University of Minnesota Medical Centers, Department of Radiology, Minneapolis, MN (United States); McKinney, Alexander M., E-mail: mckinrad@umn.edu [Hennepin County and University of Minnesota Medical Centers, Department of Radiology, Minneapolis, MN (United States)

2015-04-15

Objectives: To assess the accuracy and reliability of one vendor's (Vital Images, Toshiba Medical, Minnetonka, MN) automated CT perfusion (CTP) summary maps in identification and volume estimation of infarcted tissue in patients with acute middle cerebral artery (MCA) distribution infarcts. Subjects and methods: From 1085 CTP examinations over 5.5 years, 43 diffusion-weighted imaging (DWI)-positive patients were included who underwent both CTP and DWI <12 h after symptom onset, with another 43 age-matched patients as controls (DWI-negative). Automated delay-corrected postprocessing software (DC-SVD) generated both infarct “core only” and “core + penumbra” CTP summary maps. Three reviewers independently tabulated Alberta Stroke Program Early CT scores (ASPECTS) of both CTP summary maps and coregistered DWI. Results: Of 86 included patients, 36 had DWI infarct volumes ≤70 ml, 7 had volumes >70 ml, and 43 were negative; the automated CTP “core only” map correctly classified each as >70 ml or ≤70 ml, while the “core + penumbra” map misclassified 4 as >70 ml. There were strong correlations between DWI volume with both summary map-based volumes: “core only” (r = 0.93), and “core + penumbra” (r = 0.77) (both p < 0.0001). Agreement between ASPECTS scores of infarct core on DWI with summary maps was 0.65–0.74 for “core only” map, and 0.61–0.65 for “core + penumbra” (both p < 0.0001). Using DWI-based ASPECTS scores as the standard, the accuracy of the CTP-based maps were 79.1–86.0% for the “core only” map, and 83.7–88.4% for “core + penumbra.” Conclusion: Automated CTP summary maps appear to be relatively accurate in both the detection of acute MCA distribution infarcts, and the discrimination of volumes using a 70 ml threshold.

Archean greenstone-tonalite duality: Thermochemical mantle convection models or plate tectonics in the early Earth global dynamics?

Science.gov (United States)

Kerrich, Robert; Polat, Ali

2006-03-01

Mantle convection and plate tectonics are one system, because oceanic plates are cold upper thermal boundary layers of the convection cells. As a corollary, Phanerozoic-style of plate tectonics or more likely a different version of it (i.e. a larger number of slowly moving plates, or similar number of faster plates) is expected to have operated in the hotter, vigorously convecting early Earth. Despite the recent advances in understanding the origin of Archean greenstone-granitoid terranes, the question regarding the operation of plate tectonics in the early Earth remains still controversial. Numerical model outputs for the Archean Earth range from predominantly shallow to flat subduction between 4.0 and 2.5 Ga and well-established steep subduction since 2.5 Ga [Abbott, D., Drury, R., Smith, W.H.F., 1994. Flat to steep transition in subduction style. Geology 22, 937-940], to no plate tectonics but rather foundering of 1000 km sectors of basaltic crust, then "resurfaced" by upper asthenospheric mantle basaltic melts that generate the observed duality of basalts and tonalities [van Thienen, P., van den Berg, A.P., Vlaar, N.J., 2004a. Production and recycling of oceanic crust in the early earth. Tectonophysics 386, 41-65; van Thienen, P., Van den Berg, A.P., Vlaar, N.J., 2004b. On the formation of continental silicic melts in thermochemical mantle convection models: implications for early Earth. Tectonophysics 394, 111-124]. These model outputs can be tested against the geological record. Greenstone belt volcanics are composites of komatiite-basalt plateau sequences erupted from deep mantle plumes and bimodal basalt-dacite sequences having the geochemical signatures of convergent margins; i.e. horizontally imbricated plateau and island arc crust. Greenstone belts from 3.8 to 2.5 Ga include volcanic types reported from Cenozoic convergent margins including: boninites; arc picrites; and the association of adakites-Mg andesites- and Nb-enriched basalts. Archean cratons

Summaries of FY 1994 geosciences research

Energy Technology Data Exchange (ETDEWEB)

1994-12-01

The Geosciences Research Program is directed by the Department of Energy`s (DOE`s) Office of Energy Research (OER) through its Office of Basic Energy Sciences (OBES). Activities in the Geosciences Research Program are directed toward the long-term fundamental knowledge of the processes that transport, modify, concentrate, and emplace (1) the energy and mineral resources of the earth and (2) the energy byproducts of man. The Program is divided into five broad categories: Geophysics and earth dynamics; Geochemistry; Energy resource recognition, evaluation, and utilization; Hydrogeology and exogeochemistry; and Solar-terrestrial interactions. The summaries in this document, prepared by the investigators, describe the scope of the individual programs in these main areas and their subdivisions including earth dynamics, properties of earth materials, rock mechanics, underground imaging, rock-fluid interactions, continental scientific drilling, geochemical transport, solar/atmospheric physics, and modeling, with emphasis on the interdisciplinary areas.

A Mercury-like component of early Earth yields uranium in the core and high mantle (142)Nd.

Science.gov (United States)

Wohlers, Anke; Wood, Bernard J

2015-04-16

Recent (142)Nd isotope data indicate that the silicate Earth (its crust plus the mantle) has a samarium to neodymium elemental ratio (Sm/Nd) that is greater than that of the supposed chondritic building blocks of the planet. This elevated Sm/Nd has been ascribed either to a 'hidden' reservoir in the Earth or to loss of an early-formed terrestrial crust by impact ablation. Since removal of crust by ablation would also remove the heat-producing elements--potassium, uranium and thorium--such removal would make it extremely difficult to balance terrestrial heat production with the observed heat flow. In the 'hidden' reservoir alternative, a complementary low-Sm/Nd layer is usually considered to reside unobserved in the silicate lower mantle. We have previously shown, however, that the core is a likely reservoir for some lithophile elements such as niobium. We therefore address the question of whether core formation could have fractionated Nd from Sm and also acted as a sink for heat-producing elements. We show here that addition of a reduced Mercury-like body (or, alternatively, an enstatite-chondrite-like body) rich in sulfur to the early Earth would generate a superchondritic Sm/Nd in the mantle and an (142)Nd/(144)Nd anomaly of approximately +14 parts per million relative to chondrite. In addition, the sulfur-rich core would partition uranium strongly and thorium slightly, supplying a substantial part of the 'missing' heat source for the geodynamo.

A Model of Volcanic Outgassing for Earth's Early Atmosphere

Science.gov (United States)

Dhaliwal, J. K.; Kasting, J. F.; Zhang, Z.

2017-12-01

We build on historical paradigms of volcanic degassing [1] to account for non-linear relations among C-O-H-S volatiles, their speciation, solubility and concentrations in magmatic melts, and the resulting contribution to atmospheric volatile inventories. We focus on the build-up of greenhouse-relevant carbon species (CO2 and CH4) and molecular oxygen to better understand the environments of early life and the Great Oxygenation Event [2,3,4]. The mantle is an important reservoir of C-O-H-S volatiles [5], and melt concentrations depend on temperature, pressure and oxygen fugacity. We present a preliminary chemical model that simulates volatile concentrations released into the Earth's atmosphere at 1 bar, or pressures corresponding to the early Earth prior to 2.4 Ga. We maintain redox balance in the system using H+ [2, 6] because the melt oxidation state evolves with volatile melt concentrations [7] and affects the composition of degassed compounds. For example, low fO2 in the melt degasses CO, CH4, H2S and H2 while high fO2 yields CO2, SO2 and H2O [1,8,9]. Our calculations incorporate empirical relations from experimental petrology studies [e.g., 10, 11] to account for inter-dependencies among volatile element solubility trends. This model has implications for exploring planetary atmospheric evolution and potential greenhouse effects on Venus and Mars [12]­, and possibly exoplanets. A future direction of this work would be to link this chemical degassing model with different tectonic regimes [13] to account for degassing and ingassing, such as during subduction. References: [1] Holland, H. D. (1984) The chemical evolution of the atmosphere and oceans [2] Kasting, J. F. (2013) Chem. Geo. 362, 13-25 [3] Kasting, J.F. (1993) Sci. 259, 920-926 [4] Duncan, M.S. & Dasgupta, R. (2017) Nat. Geoscience 10, 387-392. [5] Hier-Majumder, S. & Hirschmann, M.M. (2017) G3, doi: 10.1002/2017GC006937 [6] Gaillard, F. et al. (2003) GCA 67, 2427- 2441 [7] Moussalam, Y. et al. (2014

The Formation of Haze During the Rise of Oxygen in the Atmosphere of the Early Earth

Science.gov (United States)

Horst, S. M.; Jellinek, M.; Pierrehumbert, R.; Tolbert, M. A.

2014-12-01

also provide a wealth of organic material to the surface. Photochemical hazes are abundant in reducing atmospheres, such as the N2/CH4 atmosphere of Titan, but are unlikely to form in oxidizing atmospheres, such as the N2/O2 atmosphere of present day Earth. However, information about haze formation in mildly oxidizing atmospheres is lacking. Understanding haze formation in mildly oxidizing atmospheres is necessary for models that wish to investigate the atmosphere of the Early Earth as O2 first appeared and then increased in abundance. Previous studies of the atmosphere of the Early Earth have focused on haze formation in N2/CO2/CH4 atmospheres. In this work, we experimentally investigate the effect of the addition of O2 on the formation and composition of aerosols. Using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) (see e.g. [1]) we have obtained in situ composition measurements of aerosol particles produced in N2/CO2/CH4/O2 gas mixtures subjected to FUV radiation (deuterium lamp, 115-400 nm) for a range of initial CO2/CH4/O2 mixing ratios. In particular, we studied the effect of O2 ranging from 2 ppm to 2%. The particles were also investigated using a Scanning Mobility Particle Sizer (SMPS), which measures particle size, number density and mass loading. A comparison of the composition of the aerosols will be presented. The effect of variation of O2 mixing ratio on aerosol production, size, and composition will also be discussed. [1] Trainer, M.G., et al. (2012) Astrobiology, 12, 315-326.

Microbial Communities: Tracing Growth Processes from Antarctic Lakes to Early Earth to Other Planets

Science.gov (United States)

Sumner, D. Y.

2014-12-01

Life in the Universe is dominated by microbes: they are numerically the most abundant cells in our bodies and in Earth's biosphere, and they are the only life that might be present elsewhere in our solar system. Life beyond our solar system could include macroscopic organisms, but everything we understand about the origin of life suggests it must start with microbes. Thus, understanding microbial ecosystems, in the absence of macroscopic organisms, is critical to understanding early life on Earth and life elsewhere in the Universe - if it exists. But what are the general principles of microbial ecology in the absence of predation? What happens when each cell is a chemical factory that can swap among metabolic processes in response to environmental and emergent cues? Geobiologists and astrobiologists are addressing these questions in diverse ways using both Earth's modern biosphere and its fossil record. Modern microbial communities in shallow, ice-covered lakes, Antarctica (Fig.), provide a model for high productivity microbial ecosystems with no to low predation. In these lakes, photosynthetic communities create macroscopic pinnacles and domes, sometime lithified into stromatolites. They provide an ecological, geochemical and morphological model for Precambrian microbial communities in low sedimentation, low current environments. Insights from these communities include new growth processes for ancient mats, especially some that grew prior to the oxidation of Earth's atmosphere. The diversity of biosignatures created in these communities also provides context for models of life under ice elsewhere in our solar system such as paleolakes on Mars and on icy moons. Results from the Mars Science Laboratory (MSL) team document formerly habitable fluvial and lacustrine environments. Lacustrine environments, in particular, are favorable for preserving biosignatures, and continued investigations by MSL will provide a deeper understanding of the duration of habitable

Microbiological evidence for Fe(III) reduction on early Earth

Science.gov (United States)

Vargas, Madeline; Kashefi, Kazem; Blunt-Harris, Elizabeth L.; Lovley, Derek R.

1998-09-01

It is generally considered that sulphur reduction was one of the earliest forms of microbial respiration, because the known microorganisms that are most closely related to the last common ancestor of modern life are primarily anaerobic, sulphur-reducing hyperthermophiles. However, geochemical evidence indicates that Fe(III) is more likely than sulphur to have been the first external electron acceptor of global significance in microbial metabolism. Here we show that Archaea and Bacteria that are most closely related to the last common ancestor can reduce Fe(III) to Fe(II) and conserve energy to support growth from this respiration. Surprisingly, even Thermotoga maritima, previously considered to have only a fermentative metabolism, could grow as a respiratory organism when Fe(III) was provided as an electron acceptor. These results provide microbiological evidence that Fe(III) reduction could have been an important process on early Earth and suggest that microorganisms might contribute to Fe(III) reduction in modern hot biospheres. Furthermore, our discovery that hyperthermophiles that had previously been thought to require sulphur for cultivation can instead be grown without the production of toxic and corrosive sulphide, should aid biochemical investigations of these poorly understood organisms.

182Hf, an extinct radionuclide of the early solar system and a possibly live supernova remnant on Earth

International Nuclear Information System (INIS)

Vockenhuber, C.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.; Winkler, S.; Ahmad, I.; Bichler, M.

2002-01-01

Full text: The neutron-rich isotope 182 Hf has a half-life of 9 ± 2 million years. It can be used to study the early development of the Earth and the Moon through isotopic anomalies of its stable decay product 182 W. The system 182 Hf - 182 W forms a geochronometer, which offers an excellent way to determine the time-scale for the early Solar System's accretion and the core formation of the planets. Many applications in the last few years yielded impressive results, e.g. concerning the origin of the Moon. However, the half-life of 182 Hf was measured 40 years ago, and a reduction of the large uncertainty would be very desirable. We are engaged in a re-measurement of the half-life, and the current status of this effort will be reported. 182 Hf may also complement a few other radionuclides in the million-year half-life range to trace relatively recent stellar events with high neutron fluxes in the vicinity of the Earth. This may be accomplished by finding measurable traces of live 182 Hf in suitable terrestrial archives. Since 182 Hf has no significant natural sources on earth, live 182 Hf is an ideal indicator of a recent, nearby supernova or other explosive stellar events. The AMS detection method of 182 Hf with the upgraded VERA facility, and first results of this new AMS nuclide will be presented. Refs. 2 (author)

Blue Marble Matches: Using Earth for Planetary Comparisons

Science.gov (United States)

Graff, Paige Valderrama

2009-01-01

Goal: This activity is designed to introduce students to geologic processes on Earth and model how scientists use Earth to gain a better understanding of other planetary bodies in the solar system. Objectives: Students will: 1. Identify common descriptor characteristics used by scientists to describe geologic features in images. 2. Identify geologic features and how they form on Earth. 3. Create a list of defining/distinguishing characteristics of geologic features 4. Identify geologic features in images of other planetary bodies. 5. List observations and interpretations about planetary body comparisons. 6. Create summary statements about planetary body comparisons.

Investigating the Early Atmospheres of Earth and Mars through Rivers, Raindrops, and Lava Flows

Science.gov (United States)

Som, Sanjoy M.

2010-11-01

The discovery of a habitable Earth-like planet beyond our solar-system will be remembered as one of the major breakthroughs of 21st century science, and of the same magnitude as Copernicus' heliocentric model dating from the mid 16th century. The real astrobiological breakthrough will be the added results from atmospheric remote sensing of such planets to determine habitability. Atmospheres, in both concentration and composition are suggestive of processes occurring at the planetary surface and upper crust. Unfortunately, only the modern Earth's atmosphere is known to be habitable. I investigate the density and pressure of our planet's early atmosphere before the rise of oxygen 2.5 billion years ago, because our planet was very much alive microbially. Such knowledge gives us another example of a habitable atmosphere. I also investigates the atmosphere of early Mars, as geomorphic signatures on its surface are suggestive of a past where liquid water may have present in a warmer climate, conditions suitable for the emergence of life, compared with today's 6 mbar CO2-dominated atmosphere. Using tools of fluvial geomorphology, I find that the largest river-valleys on Mars do not record a signature of a sustained hydrological cycle, in which precipitation onto a drainage basin induces many cycles of water flow, substrate incision, water ponding, and return to the atmosphere via evaporation. Rather, I conclude that while episodes of flow did occur in perhaps warmer environments, those periods were short-lived and overprinted onto a dominantly cold and dry planet. For Earth, I develop a new method of investigating atmospheric density and pressure using the size of raindrop imprints, and find that raindrop imprints preserved in the 2.7 billion year old Ventersdorp Supergroup of South Africa are consistent with precipitation falling in an atmosphere of near-surface density 0.1 kg/m3, compared to a modern value of 1.2 kg/m3, further suggesting a nitrogen level of at most

Biological modulation of planetary atmospheres: The early Earth scenario

Science.gov (United States)

Schidlowski, M.

1985-01-01

The establishment and subsequent evolution of life on Earth had a profound impact on the chemical regime at the planet's surface and its atmosphere. A thermodynamic gradient was imposed on near-surface environments that served as the driving force for a number on important geochemical transformations. An example is the redox imbalance between the modern atmosphere and the material of the Earth's crust. Current photochemical models predict extremely low partial pressures of oxygen in the Earth's prebiological atmosphere. There is widespread consensus that any large-scale oxygenation of the primitive atmosphere was contingent on the advent of biological (autotrophic) carbon fixation. It is suggested that photoautotrophy existed both as a biochemical process and as a geochemical agent since at least 3.8 Ga ago. Combining the stoichiometry of the photosynthesis reaction with a carbon isotope mass balance and current concepts for the evolution of the stationary sedimentary mass as a funion of time, it is possible to quantify, the accumulation of oxygen and its photosynthetic oxidation equivalents through Earth history.

Exposure of phototrophs to 548 days in low Earth orbit: microbial selection pressures in outer space and on early earth.

Science.gov (United States)

Cockell, Charles S; Rettberg, Petra; Rabbow, Elke; Olsson-Francis, Karen

2011-10-01

An epilithic microbial community was launched into low Earth orbit, and exposed to conditions in outer space for 548 days on the European Space Agency EXPOSE-E facility outside the International Space Station. The natural phototroph biofilm was augmented with akinetes of Anabaena cylindrica and vegetative cells of Nostoc commune and Chroococcidiopsis. In space-exposed dark controls, two algae (Chlorella and Rosenvingiella spp.), a cyanobacterium (Gloeocapsa sp.) and two bacteria associated with the natural community survived. Of the augmented organisms, cells of A. cylindrica and Chroococcidiopsis survived, but no cells of N. commune. Only cells of Chroococcidiopsis were cultured from samples exposed to the unattenuated extraterrestrial ultraviolet (UV) spectrum (>110 nm or 200 nm). Raman spectroscopy and bright-field microscopy showed that under these conditions the surface cells were bleached and their carotenoids were destroyed, although cell morphology was preserved. These experiments demonstrate that outer space can act as a selection pressure on the composition of microbial communities. The results obtained from samples exposed to >200 nm UV (simulating the putative worst-case UV exposure on the early Earth) demonstrate the potential for epilithic colonization of land masses during that time, but that UV radiation on anoxic planets can act as a strong selection pressure on surface-dwelling organisms. Finally, these experiments have yielded new phototrophic organisms of potential use in biomass and oxygen production in space exploration.

Policy Document on Earth Observation for Urban Planning and Management: State of the Art and Recommendations for Application of Earth Observation in Urban Planning

Science.gov (United States)

Nichol, Janet; King, Bruce; Xiaoli, Ding; Dowman, Ian; Quattrochi, Dale; Ehlers, Manfred

2007-01-01

A policy document on earth observation for urban planning and management resulting from a workshop held in Hong Kong in November 2006 is presented. The aim of the workshop was to provide a forum for researchers and scientists specializing in earth observation to interact with practitioners working in different aspects of city planning, in a complex and dynamic city, Hong Kong. A summary of the current state of the art, limitations, and recommendations for the use of earth observation in urban areas is presented here as a policy document.

Early Evolution of Earth's Geochemical Cycle and Biosphere: Implications for Mars Exobiology

Science.gov (United States)

DesMarais, David J.; Chang, Sherwood (Technical Monitor)

1997-01-01

Carbon (C) has played multiple key roles for life and its environment. C has formed organics, greenhouse gases, aquatic pH buffers, redox buffers, and magmatic constituents affecting plutonism and volcanism. These roles interacted across a network of reservoirs and processes known as the biogeochemical C cycle. Changes in the cycle over geologic time were driven by increasing solar luminosity, declining planetary heat flow, and continental and biological evolution. The early Archean C cycle was dominated by hydrothermal alteration of crustal rocks and by thermal emanations of CO2 and reduced species (eg., H2, Fe(2+) and sulfides). Bioorganic synthesis was achieved by nonphotosynthetic CO2-fixing bacteria (chemoautotrophs) and, possibly, bacteria (organotrophs) utilizing any available nonbiological organic C. Responding both to abundant solar energy and to a longterm decline in thermal sources of chemical energy and reducing power, the blaspheme first developed anoxygenic photosynthesis, then, ultimately, oxygenic photosynthesis. O2-photosynthesis played a central role in transforming the ancient environment and blaspheme to the modem world. The geochemical C cycles of early Earth and Mars were quite similar. The principal differences between the modem C cycles of these planets arose during the later evolution of their heat flows, crusts, atmospheres and, perhaps, their blasphemes.

A Summary of - An Earth-to-Deep Space Communications System with Adaptive Tilt and Scintillation Correction Using Near-Earth Relay Mirrors

Science.gov (United States)

Armstrong, J. W.; Yeh, C.; Wilson, K. E.

1998-01-01

Optical telecommunication will be the next technology for wide-band Earth/space communication. Uncompensated propagation through the Earth's atmosphere (e.g., scintillation and wavefront tilt) fundamentally degrade communication to distant spcaecraft.

Hybrid Differential Evolution Optimisation for Earth Observation Satellite Scheduling with Time-Dependent Earliness-Tardiness Penalties

Directory of Open Access Journals (Sweden)

Guoliang Li

2017-01-01

Full Text Available We study the order acceptance and scheduling (OAS problem with time-dependent earliness-tardiness penalties in a single agile earth observation satellite environment where orders are defined by their release dates, available processing time windows ranging from earliest start date to deadline, processing times, due dates, sequence-dependent setup times, and revenues. The objective is to maximise total revenue, where the revenue from an order is a piecewise linear function of its earliness and tardiness with reference to its due date. We formulate this problem as a mixed integer linear programming model and develop a novel hybrid differential evolution (DE algorithm under self-adaptation framework to solve this problem. Compared with classical DE, hybrid DE employs two mutation operations, scaling factor adaptation and crossover probability adaptation. Computational tests indicate that the proposed algorithm outperforms classical DE in addition to two other variants of DE.

Geosciences program annual report 1978. [LBL Earth Sciences Division

Energy Technology Data Exchange (ETDEWEB)

Witherspoon, P.A.

1978-01-01

This report is a reprint of the Geosciences section of the LBL Earth Sciences Division Annual Report 1978 (LBL-8648). It contains summary papers that describe fundamental studies addressing a variety of earth science problems of interest to the DOE. They have applications in such diverse areas as geothermal energy, oil recovery, in situ coal gasification, uranium resource evaluation and recovery, and earthquake prediction. Completed work has been reported or likely will be in the usual channels. (RWR)

The origin of the moon and the early history of the earth - a chemical model. Part 2: The earth

International Nuclear Information System (INIS)

O'Neill, H.St.C.

1991-01-01

The geochemical implications for the earth of a giant impact model for the origin of the earth-moon system are discussed, using a mass balance between three components: the proto-earth, the Impactor, and a late veneer. It is argued that the proto-earth accretes from material resembling a high temperature condensate from the solar nebula. Core formation takes place under very reducing conditions, resulting in the mantle of the proto-earth being completely stripped of all elements more siderophile than Fe, and partly depleted in the barely siderophile elements V, Cr, and perhaps Si. The Impactor then collides with the proto-earth, causing vaporisation of both the Impactor and a substantial portion of the earth's mantle. Most of this material recondenses to the earth, but some forms the moon. The Impactor adds most of the complement of the siderophile elements of the present mantle in an oxidized form. The oxidation state of the mantle is set near to its present, oxidized level. Finally, the addition of a late veneer, of composition similar to that of the H-group ordinary chondrites, accounts for the complement of the highly siderophile elements of the present mantle. The model accounts at least semi-quantitatively for the siderophile element abundances of the present mantle. Implications for the composition of the earth's core are discussed; the model predicts that neither S, O, nor Si should be present in sufficient quantities to provide the required light element in the core, whose identity, therefore, remains enigmatic

Early anaerobic metabolisms

DEFF Research Database (Denmark)

Canfield, Donald Eugene; Rosing, Minik T; Bjerrum, Christian

2006-01-01

probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity......Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were...... of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent...

The origin of volatiles in the Earth's mantle

Science.gov (United States)

Hier-Majumder, Saswata; Hirschmann, Marc M.

2017-08-01

The Earth's deep interior contains significant reservoirs of volatiles such as H, C, and N. Due to the incompatible nature of these volatile species, it has been difficult to reconcile their storage in the residual mantle immediately following crystallization of the terrestrial magma ocean (MO). As the magma ocean freezes, it is commonly assumed that very small amounts of melt are retained in the residual mantle, limiting the trapped volatile concentration in the primordial mantle. In this article, we show that inefficient melt drainage out of the freezing front can retain large amounts of volatiles hosted in the trapped melt in the residual mantle while creating a thick early atmosphere. Using a two-phase flow model, we demonstrate that compaction within the moving freezing front is inefficient over time scales characteristic of magma ocean solidification. We employ a scaling relation between the trapped melt fraction, the rate of compaction, and the rate of freezing in our magma ocean evolution model. For cosmochemically plausible fractions of volatiles delivered during the later stages of accretion, our calculations suggest that up to 77% of total H2O and 12% of CO2 could have been trapped in the mantle during magma ocean crystallization. The assumption of a constant trapped melt fraction underestimates the mass of volatiles in the residual mantle by more than an order of magnitude.Plain Language SummaryThe Earth's deep interior contains substantial amounts of volatile elements like C, H, and N. How these elements got sequestered in the Earth's interior has long been a topic of debate. It is generally assumed that most of these elements escaped the interior of the Earth during the first few hundred thousand years to create a primitive atmosphere, leaving the mantle reservoir nearly empty. In this work, we show that the key to this paradox involves the very early stages of crystallization of the mantle from a global magma ocean. Using numerical models, we show

Early Hydrodynamic Escape Limits Rocky Planets to Less Than or Equal to 1.6 Earth Radii

Science.gov (United States)

Lehmer, O. R.; Catling, D. C.

2017-01-01

In the past decade thousands of exoplanet candidates and hundreds of confirmed exoplanets have been found. For sub-Neptune-sized planets, those less than approx. 10 Earth masses, we can separate planets into two broad categories: predominantly rocky planets, and gaseous planets with thick volatile sheaths. Observations and subsequent analysis of these planets show that rocky planets are only found with radii less than approx. 1.6 Earth radii. No rocky planet has yet been found that violates this limit. We propose that hydrodynamic escape of hydrogen rich protoatmospheres, accreted by forming planets, explains the limit in rocky planet size. Following the hydrodynamic escape model employed by Luger et al. (2015), we modelled the XUV driven escape from young planets (less than approx.100 Myr in age) around a Sun-like star. With a simple, first-order model we found that the rocky planet radii limit occurs consistently at approx. 1.6 Earth radii across a wide range of plausible parameter spaces. Our model shows that hydrodynamic escape can explain the observed cutoff between rocky and gaseous planets. Fig. 1 shows the results of our model for rocky planets between 0.5 and 10 Earth masses that accrete 3 wt. % H2/He during formation. The simulation was run for 100 Myr, after that time the XUV flux drops off exponentially and hydrodynamic escape drops with it. A cutoff between rocky planets and gaseous ones is clearly seen at approx. 1.5-1.6 Earth radii. We are only interested in the upper size limit for rocky planets. As such, we assumed pure hydrogen atmospheres and the highest possible isothermal atmospheric temperatures, which will produce an upper limit on the hydrodynamic loss rate. Previous work shows that a reasonable approximation for an upper temperature limit in a hydrogen rich protoatmosphere is 2000-3000 K, consistent with our assumptions. From these results, we propose that the observed dichotomy between mini-Neptunes and rocky worlds is simply explained by

Rare-earth metal prices in the USA ca. 1960 to 1994

Science.gov (United States)

Hedrick, James B.

1997-01-01

Rare-earth metal prices were compiled from the late 1950s and early 1960s through 1994. Although commercial demand for rare-earth metals began in 1908, as the alloy mischmetal, commercial quantities of a wide range of individual rare-earth metals were not available until the late 1950s. The discovery of a large, high-grade rare-earth deposit at Mountain Pass. CA, USA, in 1949, was significant because it led to the production of commercial quantities or rare-earth elements that reduced prices and encouraged wider application of the materials. The availability of ore from Mountain Pass, and other large rare-earth deposits, especially those in Australia and China, has provided the world with abundant resources for rare-earth metal production. This availability, coupled with improved technology from Government and private-sector metallurgical research, has resulted in substantial decreases in rare-earth metal prices since the late 1950s and early 1960s. Price series for the individual rare-earth metals (except promethium) are quoted on a kilogram basis from the late 1950s and early 1960s through 1994. Prices are given in US dollars on an actual and constant dollar basis. Industrial and economic factors affecting prices during this time period are examined.

Nonproteinogenic D-amino acids at millimolar concentrations are a toxin for anaerobic microorganisms relevant to early Earth and other anoxic planets.

Science.gov (United States)

Nixon, Sophie L; Cockell, Charles S

2015-03-01

The delivery of extraterrestrial organics to early Earth provided a potentially important source of carbon and energy for microbial life. Optically active organic compounds of extraterrestrial origin exist in racemic form, yet life on Earth has almost exclusively selected for L- over D-enantiomers of amino acids. Although D-enantiomers of proteinogenic amino acids are known to inhibit aerobic microorganisms, the role of concentrated nonproteinogenic meteoritic D-amino acids on anaerobic metabolisms relevant to early Earth and other anoxic planets such as Mars is unknown. Here, we test the inhibitory effect of D-enantiomers of two nonproteinogenic amino acids common to carbonaceous chondrites, norvaline and α-aminobutyric acid, on microbial iron reduction. Three pure strains (Geobacter bemidjiensis, Geobacter metallireducens, Geopsychrobacter electrodiphilus) and an iron-reducing enrichment culture were grown in the presence of 10 mM D-enantiomers of both amino acids. Further tests were conducted to assess the inhibitory effect of these D-amino acids at 1 and 0.1 mM. The presence of 10 mM D-norvaline and D-α-aminobutyric acid inhibited microbial iron reduction by all pure strains and the enrichment. G. bemidjiensis was not inhibited by either amino acid at 0.1 mM, but D-α-aminobutyric acid still inhibited at 1 mM. Calculations using published meteorite accumulation rates to the martian surface indicate D-α-aminobutyric acid may have reached inhibitory concentrations in little over 1000 years during peak infall. These data show that, on a young anoxic planet, the use of one enantiomer over another may render the nonbiological enantiomer an environmental toxin. Processes that generate racemic amino acids in the environment, such as meteoritic infall or impact synthesis, would have been toxic processes and could have been a selection pressure for the evolution of early racemases.

Geohistory. Global evolution of the earth

Energy Technology Data Exchange (ETDEWEB)

Ozima, Minoru

1987-01-01

A full understanding of the earth's evolution can be achieved only by considering it as a continuous process starting with the birth of the solar system. This book traces the evolution of the earth, mainly on the basis of radiogenic isotopes from long half-life parent elements, and discusses it in terms of the latest developments in astrophysical theory, which impose unique constraints on the earth's origin and early evolution. By its 'historical' nature, geohistorical study also offers a unique approach to forecasting the future of the earth, yielding useful clues for the understanding of environmental problems, such as radioactive waste disposal. This book aims to provide an outline of global evolution of the planet earth for students of general science and for earth scientists.

Impact on the earth, ocean and atmosphere

International Nuclear Information System (INIS)

Ahrens, T.J.; O'Keefe, J.D.

1987-01-01

Several hundred impact craters produced historically and at times as early as 1.9 x 10/sup 9/ years ago with diameters in the range 10/sup -2/ to 10/sup 2/ km are observed on the surface of the earth. Earth-based and spacecraft observations of the surfaces of all the terrestrial planets and their satellites, as well as many of the icy satellites of the outer planets, indicated that impact cratering was a dominant process on planetary surfaces during the early history of the solar system. Moreover, the recent observation of a circumstellar disk around the nearby star, β-Pictoris, appears to be similar to the authors' own hypothesized protosolar disk. A disk of material around our sun has been hypothesized to have been the source of the solid planetesimals from which the earth and the other planets accreted by infall and capture. Thus it appears that the earth and the other terrestrial planets formed as a result of infall and impact of planetesimals. Although the present planets grew rapidly via accretion to their present size (in --10/sup 7/ years), meteorite impacts continue to occur on the earth and other planets. Until recently meteorite impact has been considered to be a process that was important on the earth and the other planets only early in the history of the solar system. This is no longer true. The Alvarez hypothesis suggests that the extinction of some 90% of all species, including 17 classes of dinosaurs, is associated with the 1 to 150 cm thick layer of noble-element rich dust which is found all over the earth exactly at the Cretaceous-Tertiary boundary. The enrichment of noble elements in this dust is in meteorite-like proportions. This dust is thought to represent the fine impact ejecta from a --10 km diameter asteroid interacting with the solid earth. The Alvarez hypothesis associates the extinction with the physics of a giant impact on the earth

Subduction on Venus and Implications for Volatile Cycling, Early Earth and Exoplanets

Science.gov (United States)

Smrekar, S. E.; Davaille, A.; Mueller, N. T.; Dyar, M. D.; Helbert, J.; Barnes, H.

2017-12-01

it a good analog of Earth's Archean. There is increasing evidence that Venus is a dynamic planet with possible active and/or recent volcanism and subduction. Studying these processes on Venus provides a window into both early Earth and offers constraints on the conditions needed to initiate plate tectonics on exoplanets.

Origin of the Early Sial Crust and U-Pb Isotope-Geochemical Heterogeneity of the Earth's Mantle

Science.gov (United States)

Mishkin, M. A.; Nozhkin, A. D.; Vovna, G. M.; Sakhno, V. G.; Veldemar, A. A.

2018-02-01

It is shown that presence of the Early Precambrian sial crust in the Indo-Atlantic segment of the Earth and its absence in the Pacific has been caused by geochemical differences in the mantle underlying these segments. These differences were examined on the basis of Nd-Hf and U-Pb isotopes in modern basalts. The U-Pb isotope system is of particular interest, since uranium is a member of a group of heat-generating radioactive elements providing heat for plumes. It is shown that in the Indo-Atlantic segment, a distribution of areas of the modern HIMU type mantle is typical, while it is almost completely absent in the Pacific segment. In the Archean, in the upper HIMU type paleo-mantle areas, plume generation and formation of the primordial basic crust occurred; this was followed by its remelting resulting in the appearance of an early sial crust forming cratons of the Indo-Atlantic segment.

Early Mission Maneuver Operations for the Deep Space Climate Observatory Sun-Earth L1 Libration Point Mission

Science.gov (United States)

Roberts, Craig; Case, Sara; Reagoso, John; Webster, Cassandra

2015-01-01

The Deep Space Climate Observatory mission launched on February 11, 2015, and inserted onto a transfer trajectory toward a Lissajous orbit around the Sun-Earth L1 libration point. This paper presents an overview of the baseline transfer orbit and early mission maneuver operations leading up to the start of nominal science orbit operations. In particular, the analysis and performance of the spacecraft insertion, mid-course correction maneuvers, and the deep-space Lissajous orbit insertion maneuvers are discussed, com-paring the baseline orbit with actual mission results and highlighting mission and operations constraints..

78 FR 38430 - Culturally Significant Objects Imported for Exhibition; Determinations: “Of Heaven and Earth: 500...

Science.gov (United States)

2013-06-26

... DEPARTMENT OF STATE [Public Notice 8359] Culturally Significant Objects Imported for Exhibition; Determinations: ``Of Heaven and Earth: 500 Years of Italian Painting From Glasgow Museums'' SUMMARY: Notice is... objects to be included in the exhibition ``Of Heaven and Earth: 500 Years of Italian Painting from Glasgow...

77 FR 27533 - Culturally Significant Objects Imported for Exhibition Determinations: “Ends of the Earth: Land...

Science.gov (United States)

2012-05-10

... DEPARTMENT OF STATE [Public Notice 7877] Culturally Significant Objects Imported for Exhibition Determinations: ``Ends of the Earth: Land Art to 1974'' SUMMARY: Notice is hereby given of the following... ``Ends of the Earth: Land Art to 1974'' imported from abroad for temporary exhibition within the United...

Can Halogen Enrichment in Reduced Enstatite Chondrites Provide Clues to Volatile Accretion in the Early Earth?

Science.gov (United States)

Clay, P. L.; Burgess, R.; Busemann, H.; Ruzié, L.; Joachim, B.; Ballentine, C.

2013-12-01

Understanding how the Earth obtained and ultimately retained its volatiles is important for our overall understanding of large scale planetary evolution. Numerous models exist for the heterogeneous accretion of volatiles to early Earth, but accounting for all elements through accretion of typical planetary building blocks (e.g., CI chondrites) is difficult. Proto-planetary collisions resulting in the accretion of volatile-poor material under reducing conditions followed by accretion of volatile-rich material under oxidizing conditions has been suggested in such models [e.g., 1]. The heavy halogens (Cl, Br and I), a group of moderately volatile elements, are excellent tracers of planetary processing due to their low abundance and incompatible nature. Therefore characterizing halogen abundance and distribution in materials that accreted to form the planets, e.g., primitive meteorites, is crucial. One group of primitive meteorites, the enstatite chondrites (EC's), are amongst the most reduced materials in the solar system as evidenced by their unique mineral assemblage. Yet despite forming under ultra-reducing conditions, they are enriched in the moderately volatile elements, such as the halogens. The ECs are of particular interest owing to their oxygen isotopic composition which plots along the terrestrial fractionation line, linking them isotopically to the Earth-Moon system. These samples can thus potentially provide clues on the accretion of moderately volatile element rich material under reducing conditions, such as it may have existed during the early stages of Earth's accretion. Chlorine, Br and I concentrations in ECs were determined through step-heating small neutron-irradiated samples (0.3 to 3.3 mg) and measured by mass spectrometry using the noble gas proxy isotopes 38ArCl/Cl, 80KrBr/Br and 128XeI/I. The EH chondrites are consistently enriched in the heavy halogens (up to 330 ppm Cl, 2290 ppb Br and 180 ppb I), compared to other ordinary and carbonaceous

KEEP Five-Year Summary Report.

Science.gov (United States)

Gallimore, Ronald; Tharp, Roland G.

This brief summary outlines the activities and findings of the research and development efforts of the Kamehameha Early Education Program (KEEP) from 1971 to 1976. The paper suggests that the original goals of the program were met and that the initial operating procedures agreed upon by KEEP and the Hawaii State Department of Education were…

The first 800 million years of earth's history

Science.gov (United States)

Smith, J. V.

1981-01-01

It is pointed out that there is no direct geological information on the first 750 Ma of earth history. Consequently the reported study is based on controversial inferences drawn from the moon, other planets and meteorites, coupled with backward extrapolation from surviving terrestrial rocks, especially those of Archaean age. Aspects of accretion are considered, taking into account cosmochemical and cosmophysical evidence, a new earth model, and convection systems. Attention is given to phase-equilibrium constraints, estimates of heat production, the bombardment history of the moon and implications for the earth, and the nature of the early crust. From a combination of physical, chemical, and petrological arguments, it is concluded that the earth's surface underwent intense volcanism in the pre-Archaean era, and that the rock types were chemically similar to those found in the early Archaean era.

Geohistory: Global evolution of the earth

International Nuclear Information System (INIS)

Ozima, M.

1987-01-01

This book traces the evolution of the Earth, mainly on the basis of radiogenic isotopes from half-life parent elements, and discusses it in terms of the latest developments in astrophysical theory, which impose unique constraints on the origin and early evolution of the earth. Owing to its historical nature, this geohistorical study offers an approach to forecasting the future of the Earth yielding clues for the understanding of environmental problems, such as radioactive waste to disposal and climate changes due to CO/sub 2/ increase

Early Opportunities Research Partnership Between Howard University, University of Maryland Baltimore County and NASA Goddard for Engaging Underrepresented STEM Students in Earth and Space Sciences

Science.gov (United States)

Misra, P.; Venable, D. D.; Hoban, S.; Demoz, B.; Bleacher, L.; Meeson, B. W.; Farrell, W. M.

2017-12-01

Howard University, University of Maryland Baltimore County and NASA Goddard Space Flight Center (GSFC) are collaborating to engage underrepresented STEM students and expose them to an early career pathway in NASA-related Earth & Space Science research. The major goal is to instill interest in Earth and Space Science to STEM majors early in their academic careers, so that they become engaged in ongoing NASA-related research, motivated to pursue STEM careers, and perhaps become part of the future NASA workforce. The collaboration builds on a program established by NASA's Dynamic Response of the Environments of Asteroids, the Moon and the moons of Mars (DREAM2) team to engage underrepresented students from Howard in summer internships. Howard leveraged this program to expand via NASA's Minority University Research and Education Project (MUREP) funding. The project pairs Howard students with GSFC mentors and engages them in cutting-edge Earth and Space Science research throughout their undergraduate tenure. The project takes a multi-faceted approach, with each year of the program specifically tailored to each student's strengths and addressing their weaknesses, so that they experience a wide array of enriching research and professional development activities that help them grow both academically and professionally. During the academic year, the students are at Howard taking a full load of courses towards satisfying their degree requirements and engaging in research with their GSFC mentors via regular telecons, e-mail exchanges, video chats & on an average one visit per semester to GSFC for an in-person meeting with their research mentor. The students extend their research with full-time summer internships at GSFC, culminating in a Capstone Project and Senior Thesis. As a result, these Early Opportunities Program students, who have undergone rigorous training in the Earth and Space Sciences, are expected to be well-prepared for graduate school and the NASA workforce.

Early non-destructive biofouling detection in spiral wound RO Membranes using a mobile earth's field NMR

KAUST Repository

Fridjonsson, E.O.; Vogt, S.J.; Vrouwenvelder, Johannes S.; Johns, M.L.

2015-01-01

We demonstrate the use of Earth's field (EF) Nuclear Magnetic Resonance (NMR) to provide early non-destructive detection of active biofouling of a commercial spiral wound reverse osmosis (RO) membrane module. The RO membrane module was actively biofouled to different extents, by the addition of biodegradable nutrients to the feed stream, as revealed by a subtle feed-channel pressure drop increase. Easily accessible EF NMR parameters (signal relaxation parameters T1, T2 and the total NMR signal modified to be sensitive to stagnant fluid only) were measured and analysed in terms of their ability to detect the onset of biofouling. The EF NMR showed that fouling near the membrane module entrance significantly distorted the flow field through the whole membrane module. The total NMR signal is shown to be suitable for non-destructive early biofouling detection of spiral wound membrane modules, it was readily deployed at high (operational) flow rates, was particularly sensitive to flow field changes due to biofouling and could be deployed at any position along the membrane module axis. In addition to providing early fouling detection, the mobile EF NMR apparatus could also be used to (i) evaluate the production process of spiral wound membrane modules, and (ii) provide an in-situ determination of module cleaning process efficiency.

Apollo experience report: Earth landing system

Science.gov (United States)

West, R. B.

1973-01-01

A brief discussion of the development of the Apollo earth landing system and a functional description of the system are presented in this report. The more significant problems that were encountered during the program, the solutions, and, in general, the knowledge that was gained are discussed in detail. Two appendixes presenting a detailed description of the various system components and a summary of the development and the qualification test programs are included.

Earth Sciences Division annual report 1980

Energy Technology Data Exchange (ETDEWEB)

1981-07-01

Summaries of the highlights of programs in the Earth Sciences Division are presented under four headings; Geosciences, Geothermal Energy Development, Nuclear Waste Isolation, and Marine Sciences. Utilizing both basic and applied research in a wide spectrum of topics, these programs are providing results that will be of value in helping to secure the nation's energy future. Separate abstracts have been prepared for each project for inclusion in the Energy Data Base. (DMC)

How did Earth not End up like Venus?

Science.gov (United States)

Jellinek, M.; Lenardic, A.; Weller, M. B.

2017-12-01

Recent geodynamic calculations show that terrestrial planets forming with a chondritic initial bulk composition at order 1 AU can evolve to be either "Earth-like" or "Venus-like": Both mobile- and stagnant-lid tectonic regimes are permitted, neither solution is an explicitly stronger attractor and effects related to differences in Sun-Earth distance are irrelevant. What factors might then cause the thermal evolutionary paths of Earth and Venus to diverge dynamically at early times? At what point in Earth's evolution did plate tectonics emerge and when and how did this tectonic mode gain sufficient resilience to persist over much of Earth's evolution? What is the role of volatile cycling and climate: To what extent have the stable climate of Earth and the greenhouse runaway climate of Venus enforced their distinct tectonic regimes over time? In this talk I will explore some of the mechanisms potentially governing the evolutionary divergence of Earth and Venus. I will first review observational constraints that suggest that Earth's entry into the current stable plate tectonic mode was far from assured by 2 Ga. Next I will discuss how models have been used to build understanding of some key dynamical controls. In particular, the probability of "Earth-like" solutions is affected by: 1) small differences in the initial concentrations of heat producing elements (i.e., planetary initial conditions); 2) long-term climate change; and 3) the character of a planet's early evolutionary path (i.e., tectonic hysteresis).

Summaries of FY 1993 geosciences research

Energy Technology Data Exchange (ETDEWEB)

1993-12-01

The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of the geosciences that are germane to the DOE`s many missions. The Geosciences Research Program is supported by the Office of Energy Research. The participants in this program include DOE laboratories, academic institutions, and other governmental agencies. These activities are formalized by a contract or grant between the DOE and the organization performing the work, providing funds for salaries, equipment, research materials, and overhead. The summaries in this document, prepared by the investigators, describe the scope of the individual programs. The Geosciences Research Program includes research in geophysics, geochemistry, resource evaluation, solar-terrestrial interactions, and their subdivisions including earth dynamics, properties of earth materials, rock mechanics, underground imaging, rock-fluid interactions, continental scientific drilling, geochemical transport, solar-atmospheric physics, and modeling, with emphasis on the interdisciplinary areas.

Earth evolution as a thermal system

Science.gov (United States)

Tang, C.

2014-12-01

After fifty years of plate-tectonic theory, the reasons why earth sometime freezed as a snowball or sometime became lethally hot resulting in mass extinction remain enigmatic. This article proposes a new hypothesis on Earth evolution. The unbalance of heat between the input and output is considered as the driving force for the Earth evolution, the lithospheric expansion and associated uplift are the triggers, the self-organized progressive failure leading to collapse of the Earth are the amplifier, and the global scale response in terms of volcanism and magmatism is the globalizer. This shallow process of lithosphere may reach a critical state with a positive feedback loop, and result in the formation of no-plume original Large Igneous Provinces (NPOLIP) in a top-down pattern. Endothermic phase changes during de-compressive melting remove heat from and cool their surroundings, including the upper parts of the lithosphere. The huge loss of Earth's heat during eruption of LIPs, together with the endothermic cooling, may put the thermal cycle to an end and a new start of the cycle initiates. In summary, Earth drives itself to evolve in terms of thermal cycles. Global cooling and warming are the two stages of the many cycles during the Earth evolution. Glaciations are the extreme result of global cooling, whereas the LIPs, sometime accompanied with remarkable sea level dropping, are the extreme result of global warming, with a long recovering age, the interglacialstage, between them. They come and go as thermal cycle evolves, with climate warming, being caused by Earth itself rather than by external forces or human activities, as the most attractive prediction.

Identifying early Earth microfossils in unsilicified sediments

Science.gov (United States)

Javaux, Emmanuelle J.; Asael, Dan; Bekker, Andrey; Debaille, Vinciane; Derenne, Sylvie; Hofmann, Axel; Mattielli, Nadine; Poulton, Simon

2013-04-01

The search for life on the early Earth or beyond Earth requires the definition of biosignatures, or "indices of life". These traditionally include fossil molecules, isotopic fractionations, biosedimentary structures and morphological fossils interpreted as remnants of life preserved in rocks. This research focuses on traces of life preserved in unsilicified siliciclastic sediments. Indeed, these deposits preserve well sedimentary structures indicative of past aqueous environments and organic matter, including the original organic walls of microscopic organisms. They also do not form in hydrothermal conditions which may be source of abiotic organics. At our knowledge, the only reported occurrence of microfossils preserved in unsilicified Archean sediments is a population of large organic-walled vesicles discovered in shales and siltstones of the 3.2 Ga Moodies Group, South Africa. (Javaux et al, Nature 2010). These have been interpreted as microfossils based on petrographic and geochemical evidence for their endogenicity and syngeneity, their carbonaceous composition, cellular morphology and ultrastructure, occurrence in populations, taphonomic features of soft wall deformation, and the geological context plausible for life, as well as lack of abiotic explanation falsifying a biological origin. Demonstrating that carbonaceous objects from Archaean rocks are truly old and truly biological is the subject of considerable debate. Abiotic processes are known to produce organics and isotopic signatures similar to life. Spheroidal pseudofossils may form as self-assembling vesicles from abiotic CM, e.g. in prebiotic chemistry experiments (Shoztak et al, 2001), from meteoritic lipids (Deamer et al, 2006), or hydrothermal fluids (Akashi et al, 1996); by artifact of maceration; by migration of abiotic or biotic CM along microfractures (VanZuilen et al, 2007) or along mineral casts (Brasier et al, 2005), or around silica spheres formed in silica-saturated water (Jones and

The bottom of the universe: Flat earth science in the Age of Encounter.

Science.gov (United States)

Allegro, James J

2017-03-01

This essay challenges the dominance of the spherical earth model in fifteenth- and early-sixteenth-century Western European thought. It examines parallel strains of Latin and vernacular writing that cast doubt on the existence of the southern hemisphere. Three factors shaped the alternate accounts of the earth as a plane and disk put forward by these sources: (1) the unsettling effects of maritime expansion on scientific thought; (2) the revival of interest in early Christian criticism of the spherical earth; and (3) a rigid empirical stance toward entities too large to observe in their entirety, including the earth. Criticism of the spherical earth model faded in the decades after Magellan's crew returned from circuiting the earth in 1522.

12 Ministries Control Rare Earth Exports

Institute of Scientific and Technical Information of China (English)

2010-01-01

<正>"It is very natural to reserve rare earth as a strategic resource.Many countries do this,including China."On April 8,Sun Lihui,Vice Director of Metal Section of Chemicals Import & Export Commerce Chamber of China Minmetals Corporation told a reporter that as early as 2006,China has launched a strategic plan for rare earth,"but it was interrupted by the subsequent financial crisis."

Interaction between drilled shaft and mechanically stabilized earth (MSE) wall : project summary.

Science.gov (United States)

2015-08-31

Drilled shafts are being constructed within the reinforced zone of mechanically stabilized earth (MSE) walls (Figure 1). The drilled shafts may be subjected to horizontal loads and push against the front of the wall. Distress of MSE wall panels has b...

Earth Sciences Division annual report 1990

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-06-01

This Annual Report presents summaries of selected representative research activities grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrogeology, Geology and Geochemistry, and Geophysics and Geomechanics. Much of the Division`s research deals with the physical and chemical properties and processes in the earth`s crust, from the partially saturated, low-temperature near-surface environment to the high-temperature environments characteristic of regions where magmatic-hydrothermal processes are active. Strengths in laboratory and field instrumentation, numerical modeling, and in situ measurement allow study of the transport of mass and heat through geologic media -- studies that now include the appropriate chemical reactions and the hydraulic-mechanical complexities of fractured rock systems. Of particular note are three major Division efforts addressing problems in the discovery and recovery of petroleum, the application of isotope geochemistry to the study of geodynamic processes and earth history, and the development of borehole methods for high-resolution imaging of the subsurface using seismic and electromagnetic waves. In 1989 a major DOE-wide effort was launched in the areas of Environmental Restoration and Waste Management. Many of the methods previously developed for and applied to deeper regions of the earth will in the coming years be turned toward process definition and characterization of the very shallow subsurface, where man-induced contaminants now intrude and where remedial action is required.

75 FR 8997 - NASA Advisory Council; Science Committee; Earth Science Subcommittee; Meeting

Science.gov (United States)

2010-02-26

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-021)] NASA Advisory Council; Science...: Notice of meeting. SUMMARY: The National Aeronautics and Space Administration (NASA) announces a meeting of the Earth Science Subcommittee of the NASA Advisory Council (NAC). This Subcommittee reports to...

Terrestrial xenon isotope constraints on the early history of the earth

International Nuclear Information System (INIS)

Ozima, M.; Igarashi, G.; Podosek, F.A.

1985-01-01

Comparison between 129 I-radiogenic 129 Xe and 244 Pu-fissiogenic 136 Xe components in terrestrial xenon suggests that the Earth's inner region accreted a few tens of millions of years earlier than the outer region from which the atmosphere evolved. The results also indicate that there has been no substantial mixing of the two regions since the Earth's accretion. (author)

Comets as Messengers from the Early Solar System - Emerging Insights on Delivery of Water, Nitriles, and Organics to Earth

Science.gov (United States)

Mumma, Michael J.; Charnley, Steven B.

2012-01-01

The question of exogenous delivery of water and organics to Earth and other young planets is of critical importance for understanding the origin of Earth's volatiles, and for assessing the possible existence of exo-planets similar to Earth. Viewed from a cosmic perspective, Earth is a dry planet, yet its oceans are enriched in deuterium by a large factor relative to nebular hydrogen and analogous isotopic enrichments in atmospheric nitrogen and noble gases are also seen. Why is this so? What are the implications for Mars? For icy Worlds in our Planetary System? For the existence of Earth-like exoplanets? An exogenous (vs. outgassed) origin for Earth's atmosphere is implied, and intense debate on the relative contributions of comets and asteroids continues - renewed by fresh models for dynamical transport in the protoplanetary disk, by revelations on the nature and diversity of volatile and rocky material within comets, and by the discovery of ocean-like water in a comet from the Kuiper Belt (cf., Mumma & Charnley 2011). Assessing the creation of conditions favorable to the emergence and sustenance of life depends critically on knowledge of the nature of the impacting bodies. Active comets have long been grouped according to their orbital properties, and this has proven useful for identifying the reservoir from which a given comet emerged (OC, KB) (Levison 1996). However, it is now clear that icy bodies were scattered into each reservoir from a range of nebular distances, and the comet populations in today's reservoirs thus share origins that are (in part) common. Comets from the Oort Cloud and Kuiper Disk reservoirs should have diverse composition, resulting from strong gradients in temperature and chemistry in the proto-planetary disk, coupled with dynamical models of early radial transport and mixing with later dispersion of the final cometary nuclei into the long-term storage reservoirs. The inclusion of material from the natal interstellar cloud is probable

High-Definition Television (HDTV) Images for Earth Observations and Earth Science Applications

Science.gov (United States)

Robinson, Julie A.; Holland, S. Douglas; Runco, Susan K.; Pitts, David E.; Whitehead, Victor S.; Andrefouet, Serge M.

2000-01-01

As part of Detailed Test Objective 700-17A, astronauts acquired Earth observation images from orbit using a high-definition television (HDTV) camcorder, Here we provide a summary of qualitative findings following completion of tests during missions STS (Space Transport System)-93 and STS-99. We compared HDTV imagery stills to images taken using payload bay video cameras, Hasselblad film camera, and electronic still camera. We also evaluated the potential for motion video observations of changes in sunlight and the use of multi-aspect viewing to image aerosols. Spatial resolution and color quality are far superior in HDTV images compared to National Television Systems Committee (NTSC) video images. Thus, HDTV provides the first viable option for video-based remote sensing observations of Earth from orbit. Although under ideal conditions, HDTV images have less spatial resolution than medium-format film cameras, such as the Hasselblad, under some conditions on orbit, the HDTV image acquired compared favorably with the Hasselblad. Of particular note was the quality of color reproduction in the HDTV images HDTV and electronic still camera (ESC) were not compared with matched fields of view, and so spatial resolution could not be compared for the two image types. However, the color reproduction of the HDTV stills was truer than colors in the ESC images. As HDTV becomes the operational video standard for Space Shuttle and Space Station, HDTV has great potential as a source of Earth-observation data. Planning for the conversion from NTSC to HDTV video standards should include planning for Earth data archiving and distribution.

Summaries of physical research in the geosciences

International Nuclear Information System (INIS)

1981-10-01

The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of earth, atmospheric, and solar-terrestrial sciences that are germane to the Department of Energy's many missions. The summaries describe the scope of the individual programs and detail the research performed during 1980 to 1981. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including the various subdivisions and interdisciplinary areas

Summaries of physical research in the geosciences

Energy Technology Data Exchange (ETDEWEB)

1981-10-01

The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of earth, atmospheric, and solar-terrestrial sciences that are germane to the Department of Energy's many missions. The summaries describe the scope of the individual programs and detail the research performed during 1980 to 1981. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including the various subdivisions and interdisciplinary areas.

National Land Imaging Requirements (NLIR) Pilot Project summary report: summary of moderate resolution imaging user requirements

Science.gov (United States)

Vadnais, Carolyn; Stensaas, Gregory

2014-01-01

Under the National Land Imaging Requirements (NLIR) Project, the U.S. Geological Survey (USGS) is developing a functional capability to obtain, characterize, manage, maintain and prioritize all Earth observing (EO) land remote sensing user requirements. The goal is a better understanding of community needs that can be supported with land remote sensing resources, and a means to match needs with appropriate solutions in an effective and efficient way. The NLIR Project is composed of two components. The first component is focused on the development of the Earth Observation Requirements Evaluation System (EORES) to capture, store and analyze user requirements, whereas, the second component is the mechanism and processes to elicit and document the user requirements that will populate the EORES. To develop the second component, the requirements elicitation methodology was exercised and refined through a pilot project conducted from June to September 2013. The pilot project focused specifically on applications and user requirements for moderate resolution imagery (5–120 meter resolution) as the test case for requirements development. The purpose of this summary report is to provide a high-level overview of the requirements elicitation process that was exercised through the pilot project and an early analysis of the moderate resolution imaging user requirements acquired to date to support ongoing USGS sustainable land imaging study needs. The pilot project engaged a limited set of Federal Government users from the operational and research communities and therefore the information captured represents only a subset of all land imaging user requirements. However, based on a comparison of results, trends, and analysis, the pilot captured a strong baseline of typical applications areas and user needs for moderate resolution imagery. Because these results are preliminary and represent only a sample of users and application areas, the information from this report should only

The capacity limitations of orientation summary statistics

Science.gov (United States)

Attarha, Mouna; Moore, Cathleen M.

2015-01-01

The simultaneous–sequential method was used to test the processing capacity of establishing mean orientation summaries. Four clusters of oriented Gabor patches were presented in the peripheral visual field. One of the clusters had a mean orientation that was tilted either left or right while the mean orientations of the other three clusters were roughly vertical. All four clusters were presented at the same time in the simultaneous condition whereas the clusters appeared in temporal subsets of two in the sequential condition. Performance was lower when the means of all four clusters had to be processed concurrently than when only two had to be processed in the same amount of time. The advantage for establishing fewer summaries at a given time indicates that the processing of mean orientation engages limited-capacity processes (Experiment 1). This limitation cannot be attributed to crowding, low target-distractor discriminability, or a limited-capacity comparison process (Experiments 2 and 3). In contrast to the limitations of establishing multiple summary representations, establishing a single summary representation unfolds without interference (Experiment 4). When interpreted in the context of recent work on the capacity of summary statistics, these findings encourage reevaluation of the view that early visual perception consists of summary statistic representations that unfold independently across multiple areas of the visual field. PMID:25810160

Early evolution and dynamics of Earth from a molten initial stage

Science.gov (United States)

Louro Lourenço, Diogo; Tackley, Paul J.

2016-04-01

It is now well established that most of the terrestrial planets underwent a magma ocean stage during their accretion. On Earth, it is probable that at the end of accretion, giant impacts like the hypothesised Moon-forming impact, together with other sources of heat, melted a substantial part of the mantle. The thermal and chemical evolution of the resulting magma ocean most certainly had dramatic consequences on the history of the planet. Considerable research has been done on magma oceans using simple 1-D models (e.g.: Abe, PEPI 1997; Solomatov, Treat. Geophys. 2007; Elkins-Tanton EPSL 2008). However, some aspects of the dynamics may not be adequately addressed in 1-D and require the use of 2-D or 3-D models. Moreover, new developments in mineral physics that indicate that melt can be denser than solid at high pressures (e.g.: de Koker et al., EPSL 2013) can have very important impacts on the classical views of the solidification of magma oceans (Labrosse et al., Nature 2007). The goal of our study is to understand and characterize the influence of melting on the long-term thermo-chemical evolution of rocky planet interiors, starting from an initial molten state (magma ocean). Our approach is to model viscous creep of the solid mantle, while parameterizing processes that involve melt as previously done in 1-D models, including melt-solid separation at all melt fractions, the use of an effective diffusivity to parameterize turbulent mixing, coupling to a parameterized core heat balance and a radiative surface boundary condition. These enhancements have been made to the numerical code StagYY (Tackley, PEPI 2008). We present results for the evolution of an Earth-like planet from a molten initial state to present day, while testing the effect of uncertainties in parameters such as melt-solid density differences, surface heat loss and efficiency of turbulent mixing. Our results show rapid cooling and crystallization until the rheological transition then much slower

Composition of the Earth's interior: the importance of early events.

Science.gov (United States)

Carlson, Richard W; Boyet, Maud

2008-11-28

The detection of excess 142Nd caused by the decay of 103Ma half-life 146Sm in all terrestrial rocks compared with chondrites shows that the chondrite analogue compositional model cannot be strictly correct, at least for the accessible portion of the Earth. Both the continental crust (CC) and the mantle source of mid-ocean ridge basalts (MORB) originate from the material characterized by superchondritic 142Nd/144Nd. Thus, the mass balance of CC plus mantle depleted by crust extraction (the MORB-source mantle) does not sum back to chondritic compositions, but instead to a composition with Sm/Nd ratio sufficiently high to explain the superchondritic 142Nd/144Nd. This requires that the mass of mantle depleted by CC extraction expand to 75-100 per cent of the mantle depending on the composition assumed for average CC. If the bulk silicate Earth has chondritic relative abundances of the refractory lithophile elements, then there must exist within the Earth's interior an incompatible-element-enriched reservoir that contains roughly 40 per cent of the Earth's 40Ar and heat-producing radioactive elements. The existence of this enriched reservoir is demonstrated by time-varying 142Nd/144Nd in Archaean crustal rocks. Calculations of the mass of the enriched reservoir along with seismically determined properties of the D'' layer at the base of the mantle allow the speculation that this enriched reservoir formed by the sinking of dense melts deep in a terrestrial magma ocean. The enriched reservoir may now be confined to the base of the mantle owing to a combination of compositionally induced high density and low viscosity, both of which allow only minimal entrainment into the overlying convecting mantle.

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science. Keqing Zong. Articles written in Journal of Earth System Science. Volume 127 Issue 3 April 2018 pp 43. Early Neoarchaean A-type granitic magmatism by crustal reworking in Singhbhum craton: Evidence from Pala Lahara area, Orissa · Abhishek Topno Sukanta Dey ...

Could the early environment of Mars have supported the development of life?

Science.gov (United States)

Mckay, Christopher P.; Stoker, Carol R.

1990-01-01

The environment of Mars and its correlation to the origin of life on earth are examined. Evidence of liquid water and nitrogen on early Mars is discussed. The similarities between the early Mars and early earth environments are described.

Sulfur in Earth's Mantle and Its Behavior During Core Formation

Science.gov (United States)

Chabot, Nancy L.; Righter,Kevin

2006-01-01

The density of Earth's outer core requires that about 5-10% of the outer core be composed of elements lighter than Fe-Ni; proposed choices for the "light element" component of Earth's core include H, C, O, Si, S, and combinations of these elements [e.g. 1]. Though samples of Earth's core are not available, mantle samples contain elemental signatures left behind from the formation of Earth's core. The abundances of siderophile (metal-loving) elements in Earth's mantle have been used to gain insight into the early accretion and differentiation history of Earth, the process by which the core and mantle formed, and the composition of the core [e.g. 2-4]. Similarly, the abundance of potential light elements in Earth's mantle could also provide constraints on Earth's evolution and core composition. The S abundance in Earth's mantle is 250 ( 50) ppm [5]. It has been suggested that 250 ppm S is too high to be due to equilibrium core formation in a high pressure, high temperature magma ocean on early Earth and that the addition of S to the mantle from the subsequent accretion of a late veneer is consequently required [6]. However, this earlier work of Li and Agee [6] did not parameterize the metalsilicate partitioning behavior of S as a function of thermodynamic variables, limiting the different pressure and temperature conditions during core formation that could be explored. Here, the question of explaining the mantle abundance of S is revisited, through parameterizing existing metal-silicate partitioning data for S and applying the parameterization to core formation in Earth.

Studying the Earth from space

Science.gov (United States)

,

1981-01-01

Space age technology contains a key to increased knowledge about the Earth's resources; this key is remote sensing detecting the nature or condition of something without actually touching it. An early and still most useful form of remote sensing is photography which records the

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science. R S Rana. Articles written in Journal of Earth System Science. Volume 122 Issue 2 April 2013 pp 289-307. Palynostratigraphy and depositional environment of Vastan Lignite Mine (Early Eocene), Gujarat, western India · M R Rao Ashok Sahni R S Rana Poonam Verma.

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

pp 485-498. Determination of rare earth and refractory trace element abundances in early solar system objects by ion microprobe · S Sahijpal K K Marhas J N Goswami · More Details Abstract Fulltext PDF. Experimental and analytical procedures devised for measurement of rare earth element (REE) abundances using a ...

Earth Sciences Division annual report 1990

International Nuclear Information System (INIS)

1991-06-01

This Annual Report presents summaries of selected representative research activities grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrogeology, Geology and Geochemistry, and Geophysics and Geomechanics. Much of the Division's research deals with the physical and chemical properties and processes in the earth's crust, from the partially saturated, low-temperature near-surface environment to the high-temperature environments characteristic of regions where magmatic-hydrothermal processes are active. Strengths in laboratory and field instrumentation, numerical modeling, and in situ measurement allow study of the transport of mass and heat through geologic media -- studies that now include the appropriate chemical reactions and the hydraulic-mechanical complexities of fractured rock systems. Of particular note are three major Division efforts addressing problems in the discovery and recovery of petroleum, the application of isotope geochemistry to the study of geodynamic processes and earth history, and the development of borehole methods for high-resolution imaging of the subsurface using seismic and electromagnetic waves. In 1989 a major DOE-wide effort was launched in the areas of Environmental Restoration and Waste Management. Many of the methods previously developed for and applied to deeper regions of the earth will in the coming years be turned toward process definition and characterization of the very shallow subsurface, where man-induced contaminants now intrude and where remedial action is required

World resources and the development of the earth's surface

International Nuclear Information System (INIS)

Sasaki, A.; Ishihara, S.; Seki, Y.

1985-01-01

This text is an examination of economic (or ore) geology, and engineering geology. Using case studies of Japan and continental North America, this work presents a geological and geochemical summary of ore-forming processes along with discussions of basic principles and approaches to modern engineering geology. Emphasizes the relationship between fossil fuel resources and the evolution of the Earth's crust. Contents - WORLD RESOURCES. The Geochemistry of Metallogenesis. The Geochemistry of Fossil Fuel Deposit. Global Evolution and the Formation of Mineral Deposits. The Development of Continents and Island Arcs and the Formation of Mineral Deposits. DEVELOPMENT OF THE EARTH'S SURFACE. Development of the Earth's Surface and Engineering Geology. Engineering Geology Methods. Features of the Ground and Bedrock in Japan. Engineering Geology - A Case Study. Geology and the Environment - Case Studies. INDEX. Principal World-Wide Metal Deposits (inside front cover). Principal World-Wide Coal, Petroleum and Uranium Deposits (inside back cover)

Serpentinization and its implications for life on the early Earth and Mars.

Science.gov (United States)

Schulte, Mitch; Blake, David; Hoehler, Tori; McCollom, Thomas

2006-04-01

Ophiolites, sections of ocean crust tectonically displaced onto land, offer significant potential to support chemolithoautotrophic life through the provision of energy and reducing power during aqueous alteration of their highly reduced mineralogies. There is substantial chemical disequilibrium between the primary olivine and pyroxene mineralogy of these ophiolites and the fluids circulating through them. This disequilibrium represents a potential source of chemical energy that could sustain life. Moreover, E (h)-pH conditions resulting from rock- water interactions in ultrabasic rocks are conducive to important abiotic processes antecedent to the origin of life. Serpentinization--the reaction of olivine- and pyroxene-rich rocks with water--produces magnetite, hydroxide, and serpentine minerals, and liberates molecular hydrogen, a source of energy and electrons that can be readily utilized by a broad array of chemosynthetic organisms. These systems are viewed as important analogs for potential early ecosystems on both Earth and Mars, where highly reducing mineralogy was likely widespread in an undifferentiated crust. Secondary phases precipitated during serpentinization have the capability to preserve organic or mineral biosignatures. We describe the petrology and mineral chemistry of an ophiolite-hosted cold spring in northern California and propose criteria to aid in the identification of serpentinizing terranes on Mars that have the potential to harbor chemosynthetic life.

Environmental Consequences of Big Nasty Impacts on the Early Earth

Science.gov (United States)

Zahnle, Kevin

2015-01-01

The geological record of the Archean Earth is spattered with impact spherules from a dozen or so major cosmic collisions involving Earth and asteroids or comets (Lowe, Byerly 1986, 2015). Extrapolation of the documented deposits suggests that most of these impacts were as big or bigger than the Chicxulub event that famously ended the reign of the thunder lizards. As the Archean impacts were greater, the environmental effects were also greater. The number and magnitude of the impacts is bounded by the lunar record. There are no lunar craters bigger than Chicxulub that date to Earth's mid-to-late Archean. Chance dictates that Earth experienced no more than approximately 10 impacts bigger than Chicxulub between 2.5 billion years and 3.5 2.5 billion years, the biggest of which were approximately30-100 times more energetic, comparable to the Orientale impact on the Moon (1x10 (sup 26) joules). To quantify the thermal consequences of big impacts on old Earth, we model the global flow of energy from the impact into the environment. The model presumes that a significant fraction of the impact energy goes into ejecta that interact with the atmosphere. Much of this energy is initially in rock vapor, melt, and high speed particles. (i) The upper atmosphere is heated by ejecta as they reenter the atmosphere. The mix of hot air, rock vapor, and hot silicates cools by thermal radiation. Rock raindrops fall out as the upper atmosphere cools. (ii) The energy balance of the lower atmosphere is set by radiative exchange with the upper atmosphere and with the surface, and by evaporation of seawater. Susequent cooling is governed by condensation of water vapor. (iii) The oceans are heated by thermal radiation and rock rain and cooled by evaporation. Surface waters become hot and salty; if a deep ocean remains it is relatively cool. Subsequently water vapor condenses to replenish the oceans with hot fresh water (how fresh depending on continental weathering, which might be rather rapid

From Neurons to Neighborhoods: An Update--Workshop Summary

Science.gov (United States)

Olson, Steve

2012-01-01

"From Neurons to Neighborhoods: An Update: Workshop Summary" is based on the original study "From Neurons to Neighborhoods: Early Childhood Development," which was released in October of 2000. From the time of the original publication's release, much has occurred to cause a fundamental reexamination of the nation's…

Origin and earliest state of the earth's hydrosphere

International Nuclear Information System (INIS)

Cogley, J.G.; Henderson-Sellers, A.

1984-01-01

The origin and earliest history of the earth's hydrosphere, the inventory of excess volatiles defined by Rubey in 1951, can be constrained within wide but useful limits by a consideration of empirical and theoretical evidence from astrophysics and geology. Models for the evolution of the solar system from the protoplanetary nebula and for the growth of the earth to its present dimensions suggest quite strongly that the hydrosphere came into being during accretion. Its format, with H 2 O mostly in the oceans, CO 2 mostly in sediments, and a residual atmosphere dominated by N 2 , CO 2 , and H 2 O was established at a very early data and has persisted without large, destabilizing climatic excursions until the present day. Alternative accounts of early history, in which the earth either loses a massive primordial atmosphere or acquires its secondary atmosphere by gradual degassing, seem improbable on the basis of a series of circumstantial but cumulatively persuasive arguments. The difficulty of dissipating a massive atmosphere of solar composition in reasonable times, the likelihood that accretion was a highly energetic process and that it triggered early segregation of the core, and the tendency of the planet to accumulate volatiles preferentially in the later stages of accretion are examples of arguments favoring an early origin for the hydrosphere. Several geological isotope systems which can be sampled today require early separation of the atmosphere and probably the hydrosphere ass a whole; these systems recorrd radiogenic enrichment patterns in the noble gases and stable isotope fractionations which suggest an early origin of the biosphere. Certain geological indicators of atmsopheric composition. and the broadly equable character of the rock record, are also consistent with a hydrosphere established in the earliest stages of history and having an initial neutral or weakly reduced composition

Thermal structure of the accreting earth

International Nuclear Information System (INIS)

Turcotte, D.L.; Pflugrath, J.C.

1985-01-01

The energy associated with the accretion of the earth and the segregation of the core is more than sufficient to melt the entire earth. In order to understand the thermal evolution of the early earth it is necessary to study the relevant heat transfer mechanisms. In this paper we postulate the existence of a global magma ocean and carry out calculations of the heat flux through it in order to determine its depth. In the solid mantle heat is transferred by the upward migration of magma. This magma supplies the magma ocean. The increase in the mantle liquidus with depth (pressure) is the dominant effect influencing heat transfer through the magma ocean. We find that a magma ocean with a depth of the order of 20 km would have existed as the earth accreted. We conclude that the core segregated and an atmosphere was formed during accretion

The radioactive earth

International Nuclear Information System (INIS)

Plant, J.A.; Saunders, A.D.

1996-01-01

Uranium, thorium and potassium are the main elements contributing to natural terrestrial radioactivity. The isotopes 238 U, 235 U, 232 Th and 40 K decay with half-lives so long that significant amounts remain in the earth, providing a continuing source of heat. The slow decay of these isotopes also provides the basis for radiometric age dating and isotopic modelling of the evolution of the earth and its crust. There is a complex interplay between their heat production and the processes involved in crust formation. Phenomena such as volcanism, earthquakes, and large-scale hydrothermal activity associated with ore deposition reflect the dissipation of heat energy from the earth, much of which is derived from natural radioactivity. The higher levels of radioactive elements during the early history of the earth resulted in higher heat flow. All three of the radioactive elements are strongly partitioned into the continental crust, but within the crust their distribution is determined by their different chemical properties. The behaviour of U, which has two commonly occurring oxidation states, is more complex than that of Th and K. Uranium deposits are diverse, and are mostly associated with granites, acid volcanics, or detrital sedimentary rocks. The most important U deposits economically are unconformity-type ores of Proterozoic age, in which U is enriched by up to 5 x 10 6 with respect to bulk earth values. In some cases natural radioactivity can be of environmental concern. The most significant risk is posed by accumulations of radon, the gaseous daughter product of U. (author)

UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

Energy Technology Data Exchange (ETDEWEB)

Rugheimer, S.; Sasselov, D. [Harvard Smithsonian Center for Astrophysics, 60 Garden st., 02138 MA Cambridge (United States); Segura, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México (Mexico); Kaltenegger, L., E-mail: srugheimer@cfa.harvard.edu [Carl Sagan Institute, Cornell University, Ithaca, NY 14853 (United States)

2015-06-10

The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars in the circumstellar Habitable Zone for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early-Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present-day levels at 2.0 Gyr ago, 0.8 Gyr ago, and modern Earth. In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth–Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5 V) receives 300 times less biologically effective radiation, about 2 times modern Earth–Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments.

UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

International Nuclear Information System (INIS)

Rugheimer, S.; Sasselov, D.; Segura, A.; Kaltenegger, L.

2015-01-01

The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars in the circumstellar Habitable Zone for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early-Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present-day levels at 2.0 Gyr ago, 0.8 Gyr ago, and modern Earth. In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth–Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5 V) receives 300 times less biologically effective radiation, about 2 times modern Earth–Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments

Summary statement on fundamental geochemistry needs for nuclear waste isolation

International Nuclear Information System (INIS)

Giletti, B.J.

1985-01-01

A summary of basic geochemical research needs for high-level nuclear waste isolation is given. The focus of the paper is on the transport of alkalis and alkaline earths, particularly, Sr 90 and Cs 137 . The discussion addresses: 1)diffusion kinetics of different elements in crystalline solids; 2)transport kinetics along mineral grain boundaries; 3)natural rock systems that have undergone water circulation and isotope exchange; and 4)the techniques, feasibility, and promise of experimental efforts

Earth and environmental science in the 1980's: Part 1: Environmental data systems, supercomputer facilities and networks

Science.gov (United States)

1986-01-01

Overview descriptions of on-line environmental data systems, supercomputer facilities, and networks are presented. Each description addresses the concepts of content, capability, and user access relevant to the point of view of potential utilization by the Earth and environmental science community. The information on similar systems or facilities is presented in parallel fashion to encourage and facilitate intercomparison. In addition, summary sheets are given for each description, and a summary table precedes each section.

Possible role of radon in prebiotic chemistry and in early evolution of life on earth

International Nuclear Information System (INIS)

Zagorski, Z.P.

2010-01-01

Radon in the environment of early Earth was present in sites, determined by location of deposits of uranium, in very different geological formations. According to the decay of uranium-238, the total production of radon at the beginnings was twice as high as now and was continuously diminishing to the present levels. This nuclide could not play as big a role as do radioactive elements connected with the presence of high concentration of 235 U, which was high enough in some places to give rise to formation of natural nuclear fission reactors (e.g. Oklo phenomenon in Africa). The main role of ionizing radiation in prebiotic chemistry and biological evolution was played by low LET (linear energy transfer) radiations, as deep penetrating sources of external energy. High LET radiations are of low penetration and could act only superficially. Radon is an exception, due to its easy transfer in the air. Therefore, it could play a role already in the cases of these early organisms which exhibited the gaseous exchange of chemical compounds with the surrounding atmosphere. The action was destructive, but, on the other hand, was also mutagenic. Nevertheless, the general quantitative effect of radon on the global scale could not be larger than of other radioactive nuclides. Presented considerations are part of the chapter by the present author on the role of nuclear and radiation chemistry in astrobiology, in the monograph published by American Scientific Publishers. (author)

Mergeable summaries

DEFF Research Database (Denmark)

Agarwal, Pankaj K.; Graham, Graham; Huang, Zengfeng

2013-01-01

We study the mergeability of data summaries. Informally speaking, mergeability requires that, given two summaries on two datasets, there is a way to merge the two summaries into a single summary on the two datasets combined together, while preserving the error and size guarantees. This property m...

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 121; Issue 1. A fruit wing of Shorea Roxb. from the Early Miocene ... A new fossil fruit wing of Shorea Roxb. belonging to the family Dipterocarpaceae is described from the Early Miocene sediments of Kachchh, Gujarat. It resembles best the extant species Shorea ...

Experimental study of heterogeneous organic chemistry induced by far ultraviolet light: Implications for growth of organic aerosols by CH3 addition in the atmospheres of Titan and early Earth

Science.gov (United States)

Hong, Peng; Sekine, Yasuhito; Sasamori, Tsutoni; Sugita, Seiji

2018-06-01

Formation of organic aerosols driven by photochemical reactions has been observed and suggested in CH4-containing atmospheres, including Titan and early Earth. However, the detailed production and growth mechanisms of organic aerosols driven by solar far ultraviolet (FUV) light remain poorly constrained. We conducted laboratory experiments simulating photochemical reactions in a CH4sbnd CO2 atmosphere driven by the FUV radiations dominated by the Lyman-α line. In the experiments, we analyzed time variations in thickness and infrared spectra of solid organic film formed on an optical window in a reaction cell. Gas species formed by FUV irradiation were also analyzed and compared with photochemical model calculations. Our experimental results show that the growth rate of the organic film decreases as the CH4/CO2 ratio of reactant gas mixture decreases, and that the decrease becomes very steep for CH4/CO2 organic film but that the addition reaction of CH3 radicals onto the organic film with the reaction probability around 10-2 can explain the growth rate. At CH4/CO2 organic film. Our results suggest that organic aerosols would grow through CH3 addition onto the surface during the precipitation of aerosol particles in the middle atmosphere of Titan and early Earth. On Titan, effective CH3 addition would reduce C2H6 production in the atmosphere. On early Earth, growth of aerosol particles would be less efficient than those on Titan, possibly resulting in small-sized monomers and influencing UV shielding.

Creating a multi-national development platform: Thorium energy and rare earth value chain

International Nuclear Information System (INIS)

Kennedy, J.; Kutsch, J.

2014-01-01

Rare earths and thorium are linked at the mineralogical level. Changes in thorium regulations and liabilities resulted in the development of excessive market concentrations in the rare earth value chain. High value monazite rare earth resources, a by-product of heavy mineral sands mining, constituted a significant portion of global rare earth supply (and nearly 100% of heavy rare earths) until legislative changes, interpretation and enforcement regarding “source materials” in the early 1980s eliminated these materials from the supply chain.

Simulation of Prebiotic Processing by Comet and Meteoroid Impact: Implications for Life on Early Earth and Other Planets

Science.gov (United States)

Dateo, Christopher E.

2003-01-01

We develop a reacting flow model to simulate the shock induced chemistry of comets and meteoroids entering planetary atmospheres. Various atmospheric compositions comprising of simpler molecules (i.e., CH4, CO2, H2O, etc.) are investigated to determine the production efficiency of more complex prebiotic molecules as a function of composition, pressure, and entry velocity. The possible role of comets and meteoroids in creating the inventory of prebiotic material necessary for life on Early Earth is considered. Comets and meteoroids can also introduce new materials from the Interstellar Medium (ISM) to planetary atmospheres. The ablation of water from comets, introducing the element oxygen into Titan's atmosphere will also be considered and its implications for the formation of organic and prebiotic material.

Summaries of FY 92 geosciences research

Energy Technology Data Exchange (ETDEWEB)

1992-12-01

The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of the geosciences that are germane to the Department of Energy's many missions. The Division of Engineering and Geosciences, part of the Office of Basic Energy Sciences of the Office of Energy Research, supports the Geosciences Research Program. The participants in this program include Department of Energy laboratories, academic institutions, and other governmental agencies. These activities are formalized by a contract or grant between the Department of Energy and the organization performing the work, providing funds for salaries, equipment, research materials, and overhead. The summaries in this document, prepared by the investigators, describe the scope of the individual programs. The Geosciences Research Program includes research in geophysics, geochemistry, resource evaluation, solar-terrestrial interactions and their subdivisions including Earth dynamics, properties of Earth materials, rock mechanics, underground imaging, rock-fluid interactions, continental scientific drilling, geochemical transport, solar/atmospheric physics, and modeling, with emphasis on the interdisciplinary areas. All such research is related either directly or indirectly to the Department of Energy's long-range technological needs.

Were Ocean Impacts an Important Mechanism to Deliver Meteoritic Organic Matter to the Early Earth? Some Inferences from Eltanin

Science.gov (United States)

Kyte, Frank T.; Gersonde, Rainer; Kuhn. Gerhard

2002-01-01

Several workers have addressed the potential for extraterrestrial delivery of volatles, including water and complex organic compounds, to the early Earth. For example, Chyba and Sagan (1992) argued that since impacts would destroy organic matter, most extraterrestrial organics must be delivered in the fine-fractions of interplanetary dust. More recent computer simulations (Pierazzo and Chyba, 1999), however, have shown that substantial amounts of amino acids may survive the impacts of large (km-sized) comets and that this may exceed the amounts derived from IDPs or Miller-Urey synthesis in the atmosphere. Once an ocean developed on the early Earth, impacts of small ,asteroids and comets into deep-ocean basins were potentially common and may have been the most likely events to deliver large amounts of organics. The deposits of the late Pliocene impact of the Eltanin asteroid into the Bellingshausen Sea provide the only record of a deep-ocean (approx. 5 km) impact that can be used to constrain models of these events. This impact was first discovered in 1981 as an Ir anomaly in sediment cores collected by the USNS Eltanin in 1965 (Kyte et al., 1981). In 1995, Polarstem expedition ANT XII/4 made the first geological survey of the suspected impact region. Three sediment cores sampled around the San Martin seamounts (approx. 57.5S, 91 W) contained well-preserved impact deposits that include disturbed ocean sediments and meteoritic impact ejecta (Gersonde et al., 1997). The latter is composed of shock- melted asteroidal materials and unmelted meteorites. In 2001, the FS Polarstem returned to the impact area during expedition ANT XVIII/5a. At least 16 cores were recovered that contain ejecta deposits. These cores and geophysical data from the expedition can be used to map the effects of the impact over a large region of the ocean floor.

[Establishment of malaria early warning system in Jiangsu Province II application of digital earth system in malaria epidemic management and surveillance].

Science.gov (United States)

Wang, Wei-Ming; Zhou, Hua-Yun; Liu, Yao-Bao; Li, Ju-Lin; Cao, Yuan-Yuan; Cao, Jun

2013-04-01

To explore a new mode of malaria elimination through the application of digital earth system in malaria epidemic management and surveillance. While we investigated the malaria cases and deal with the epidemic areas in Jiangsu Province in 2011, we used JISIBAO UniStrong G330 GIS data acquisition unit (GPS) to collect the latitude and longitude of the cases located, and then established a landmark library about early-warning areas and an image management system by using Google Earth Free 6.2 and its image processing software. A total of 374 malaria cases were reported in Jiangsu Province in 2011. Among them, there were 13 local vivax malaria cases, 11 imported vivax malaria cases from other provinces, 20 abroad imported vivax malaria cases, 309 abroad imported falciparum malaria cases, 7 abroad imported quartan malaria cases (Plasmodium malaria infection), and 14 abroad imported ovale malaria cases (P. ovale infection). Through the analysis of Google Earth Mapping system, these malaria cases showed a certain degree of aggregation except the abroad imported quartan malaria cases which were highly sporadic. The local vivax malaria cases mainly concentrated in Sihong County, the imported vivax malaria cases from other provinces mainly concentrated in Suzhou City and Wuxi City, the abroad imported vivax malaria cases concentrated in Nanjing City, the abroad imported falciparum malaria cases clustered in the middle parts of Jiangsu Province, and the abroad imported ovale malaria cases clustered in Liyang City. The operation of Google Earth Free 6.2 is simple, convenient and quick, which could help the public health authority to make the decision of malaria prevention and control, including the use of funds and other health resources.

Amino Acid Stability in the Early Oceans

Science.gov (United States)

Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J. L.

2015-01-01

It is likely that a variety of amino acids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" amino acids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein amino acids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these amino acids could have persisted before their destruction by abiotic and biotic processes. Prior to life, amino acid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine amino acid life-time would have been shorter. After life, amino acids in the oceans could have been assimilated by primitive organisms.

Early evolution of the earth - Accretion, atmosphere formation, and thermal history

Science.gov (United States)

Abe, Yutaka; Matsui, Takafumi

1986-01-01

The thermal and atmospheric evolution of the earth growing planetesimal impacts are studied. The generation of an H2O protoatmosphere is examined, and the surface temperatures are estimated. The evolution of an impact-induced H2O atmosphere is analyzed. Consideration is given to the formation time of a 'magma ocean'and internal water budgets. The thermal history of an accreting earth is reviewed. The wet convection and greenhouse effects are discussed, and the role of Fe oxidation on the evolution of an impact-induced H2O atmopshere is described. The relationship between differentiation processes and core segregation, the H2O and FeO content of the mantle, and the origin of the hydrosphere is also examined.

Earth's Paleomagnetosphere and Planetary Habitability

Science.gov (United States)

Tarduno, J. A.; Blackman, E. G.; Oda, H.; Bono, R. K.; Carroll-Nellenback, J.; Cottrell, R. D.; Nimmo, F.

2017-12-01

The geodynamo is thought to play an important role in protecting Earth's hydrosphere, vital for life as we know it, from loss due to the erosive potential of the solar wind. Here we consider the mechanisms and history of this shielding. A larger core dynamo magnetic field strength provides more pressure to abate the solar wind dynamic pressure, increasing the magnetopause radius. However, the larger magnetopause also implies a larger collecting area for solar wind flux during phases of magnetic reconnection. The important variable is not mass capture but energy transfer, which does not scale linearly with magnetosphere size. Moreover, the ordered field provides the magnetic topology for recapturing atmospheric components in the opposite hemisphere such that the net global loss might not be greatly affected. While a net protection role for magnetospheres is suggested, forcing by the solar wind will change with stellar age. Paleomagnetism utilizing the single silicate crystal approach, defines a relatively strong field some 3.45 billion years ago (the Paleoarchean), but with a reduced magnetopause of 5 Earth radii, implying the potential for some atmospheric loss. Terrestrial zircons from the Jack Hills (Western Australia) and other localities host magnetic inclusions, whose magnetization has now been recorded by a new generation of ultra-sensitive 3-component SQUID magnetometer (U. Rochester) and SQUID microscope (GSJ/AIST). Paleointensity data suggest the presence of a terrestrial dynamo and magnetic shielding for Eoarchean to Hadean times, at ages as old as 4.2 billion years ago. However, the magnetic data suggest that for intervals >100,000 years long, magnetopause standoff distances may have reached 3 to 4 Earth radii or less. The early inception of the geodynamo, which probably occurred shortly after the lunar-forming impact, its continuity, and an early robust hydrosphere, appear to be key ingredients for Earth's long-term habitability.

Apollo 16 landing site: Summary of earth based remote sensing data, part W

Science.gov (United States)

Zisk, S. H.; Masursky, H.; Milton, D. J.; Schaber, G. G.; Shorthill, R. W.; Thompson, T. W.

1972-01-01

Infrared and radar studies of the Apollo 16 landing site are summarized. Correlations and comparisons between earth based remote sensing data, IR observations, and other data are discussed in detail. Remote sensing studies were devoted to solving two problems: (1) determining the physical difference between Cayley and Descartes geologic units near the landing site; and (2) determining the nature of the bright unit of Descartes mountain material.

Earth orientation from lunar laser ranging and an error analysis of polar motion services

Science.gov (United States)

Dickey, J. O.; Newhall, X. X.; Williams, J. G.

1985-01-01

Lunar laser ranging (LLR) data are obtained on the basis of the timing of laser pulses travelling from observatories on earth to retroreflectors placed on the moon's surface during the Apollo program. The modeling and analysis of the LLR data can provide valuable insights into earth's dynamics. The feasibility to model accurately the lunar orbit over the full 13-year observation span makes it possible to conduct relatively long-term studies of variations in the earth's rotation. A description is provided of general analysis techniques, and the calculation of universal time (UT1) from LLR is discussed. Attention is also given to a summary of intercomparisons with different techniques, polar motion results and intercomparisons, and a polar motion error analysis.

Summary reports of the R and D programme: recycling of non-ferrous metals (1986-1989)

International Nuclear Information System (INIS)

Donato, M.

1992-01-01

This document contains the summary reports of cost sharing research and development contracts funded under the recycling of non-ferrous metals subprogramme of the Commission of the European Communities. In particular from p.171 to 212 is described the recovery of rare earths by supported liquid membranes: synthesis and use of new selective macrocyclic and/or compartmental ligands

Annual review of earth and planetary sciences. Volume 16

International Nuclear Information System (INIS)

Wetherill, G.W.; Albee, A.L.; Stehli, F.G.

1988-01-01

Various papers on earth and planetary science topics are presented. The subjects addressed include: role and status of earth science field work; phase relations of prealuminous granitic rocks and their petrogenetic implications; chondritic meteorites and the solar nebula; volcanic winters; mass wasting on continental margins; earthquake ground motions; ore deposits as guides to geologic history of the earth; geology of high-level nuclear waste disposal; and tectonic evolution of the Caribbean. Also discussed are: the earth's rotation; the geophysics of a restless caldera (Long Valley, California); observations of cometary nuclei; geology of Venus; seismic stratigraphy; in situ-produced cosmogenic isotopes in terrestrial rocks; time variations of the earth's magnetic field; deep slabs, geochemical heterogeneity, and the large-scale structure of mantle convection; early proterozoic assembly and growth of Laurentia; concepts and methods of high-resolution event stratigraphy

Early pharmaceutical profiling to predict oral drug absorption

DEFF Research Database (Denmark)

Bergström, Christel A S; Holm, René; Jørgensen, Søren Astrup

2014-01-01

Preformulation measurements are used to estimate the fraction absorbed in vivo for orally administered compounds and thereby allow an early evaluation of the need for enabling formulations. As part of the Oral Biopharmaceutical Tools (OrBiTo) project, this review provides a summary of the pharmac......Preformulation measurements are used to estimate the fraction absorbed in vivo for orally administered compounds and thereby allow an early evaluation of the need for enabling formulations. As part of the Oral Biopharmaceutical Tools (OrBiTo) project, this review provides a summary...... and state-of-the art methodologies to study API properties impacting on oral absorption are reviewed. Assays performed during early development, i.e. physicochemical characterization, dissolution profiles under physiological conditions, permeability assays and the impact of excipients on these properties...

Meteorite Impact-Induced Rapid NH3 Production on Early Earth: Ab Initio Molecular Dynamics Simulation

Science.gov (United States)

Shimamura, Kohei; Shimojo, Fuyuki; Nakano, Aiichiro; Tanaka, Shigenori

2016-12-01

NH3 is an essential molecule as a nitrogen source for prebiotic amino acid syntheses such as the Strecker reaction. Previous shock experiments demonstrated that meteorite impacts on ancient oceans would have provided a considerable amount of NH3 from atmospheric N2 and oceanic H2O through reduction by meteoritic iron. However, specific production mechanisms remain unclear, and impact velocities employed in the experiments were substantially lower than typical impact velocities of meteorites on the early Earth. Here, to investigate the issues from the atomistic viewpoint, we performed multi-scale shock technique-based ab initio molecular dynamics simulations. The results revealed a rapid production of NH3 within several picoseconds after the shock, indicating that shocks with greater impact velocities would provide further increase in the yield of NH3. Meanwhile, the picosecond-order production makes one expect that the important nitrogen source precursors of amino acids were obtained immediately after the impact. It was also observed that the reduction of N2 proceeded according to an associative mechanism, rather than a dissociative mechanism as in the Haber-Bosch process.

Paleomagnetism of late Archaean flood basalt terrains : implications for early Earth geodynamics and geomagnetism

NARCIS (Netherlands)

Strik, G.H.M.A.

2004-01-01

Palaeomagnetic studies are e.g. important for demonstrating and quantifying horizontal movement and rotation of pieces of the Earth's crust. The constant movement and recycling of plates, in other words plate tectonics, is an important mechanism for the Earth to lose its heat. It is generally

A Tale of Two Earths: Reconciling the Lunar and Terrestrial Hadean Records

OpenAIRE

Boehnke, Patrick

2016-01-01

Studying early Earth history is complicated by the fact that the rock record doesn’t extend past 4 Ga and our only record for the Hadean (>4 Ga) comes to us from detrital zircons from the Jack Hills in Western Australia. The Hadean zircon record extends back to almost 4.4 Ga and has revealed that the early Earth may have had liquid water, a felsic crust, plate boundary interactions, and possibly a biosphere. On the other hand, analyses of lunar and meteoritic samples are used to argue for a...

Current NASA Earth Remote Sensing Observations

Science.gov (United States)

Luvall, Jeffrey C.; Sprigg, William A.; Huete, Alfredo; Pejanovic, Goran; Nickovic, Slobodan; Ponce-Campos, Guillermo; Krapfl, Heide; Budge, Amy; Zelicoff, Alan; Myers, Orrin;

Arctic tipping points in an Earth system perspective.

Science.gov (United States)

Wassmann, Paul; Lenton, Timothy M

2012-02-01

We provide an introduction to the volume The Arctic in the Earth System perspective: the role of tipping points. The terms tipping point and tipping element are described and their role in current science, general debates, and the Arctic are elucidated. From a wider perspective, the volume focuses upon the role of humans in the Arctic component of the Earth system and in particular the envelope for human existence, the Arctic ecosystems. The Arctic climate tipping elements, the tipping elements in Arctic ecosystems and societies, and the challenges of governance and anticipation are illuminated through short summaries of eight publications that derive from the Arctic Frontiers conference in 2011 and the EU FP7 project Arctic Tipping Points. Then some ideas based upon resilience thinking are developed to show how wise system management could ease pressures on Arctic systems in order to keep them away from tipping points.

Heat-pipe Earth.

Science.gov (United States)

Moore, William B; Webb, A Alexander G

2013-09-26

The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics.

Chemodynamical deuterium fractionation in the early solar nebula: The origin of water on earth and in asteroids and comets

Energy Technology Data Exchange (ETDEWEB)

Albertsson, T.; Semenov, D.; Henning, Th., E-mail: albertsson@mpia.de [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

2014-03-20

Formation and evolution of water in the solar system and the origin of water on Earth constitute one of the most interesting questions in astronomy. The prevailing hypothesis for the origin of water on Earth is by delivery through water-rich small solar system bodies. In this paper, the isotopic and chemical evolution of water during the early history of the solar nebula, before the onset of planetesimal formation, is studied. A gas-grain chemical model that includes multiply deuterated species and nuclear spin-states is combined with a steady-state solar nebula model. To calculate initial abundances, we simulated 1 Myr of evolution of a cold and dark TMC-1-like prestellar core. Two time-dependent chemical models of the solar nebula are calculated over 1 Myr: (1) a laminar model and (2) a model with two-dimensional (2D) turbulent mixing. We find that the radial outward increase of the H{sub 2}O D/H ratio is shallower in the chemodynamical nebular model than in the laminar model. This is related to more efficient defractionation of HDO via rapid gas-phase processes because the 2D mixing model allows the water ice to be transported either inward and thermally evaporated or upward and photodesorbed. The laminar model shows the Earth water D/H ratio at r ≲ 2.5 AU, whereas for the 2D chemodynamical model this zone is larger, r ≲ 9 AU. Similarly, the water D/H ratios representative of the Oort-family comets, ∼2.5-10 × 10{sup –4}, are achieved within ∼2-6 AU and ∼2-20 AU in the laminar and the 2D model, respectively. We find that with regards to the water isotopic composition and the origin of the comets, the mixing model seems to be favored over the laminar model.

Chemodynamical deuterium fractionation in the early solar nebula: The origin of water on earth and in asteroids and comets

International Nuclear Information System (INIS)

Albertsson, T.; Semenov, D.; Henning, Th.

2014-01-01

Formation and evolution of water in the solar system and the origin of water on Earth constitute one of the most interesting questions in astronomy. The prevailing hypothesis for the origin of water on Earth is by delivery through water-rich small solar system bodies. In this paper, the isotopic and chemical evolution of water during the early history of the solar nebula, before the onset of planetesimal formation, is studied. A gas-grain chemical model that includes multiply deuterated species and nuclear spin-states is combined with a steady-state solar nebula model. To calculate initial abundances, we simulated 1 Myr of evolution of a cold and dark TMC-1-like prestellar core. Two time-dependent chemical models of the solar nebula are calculated over 1 Myr: (1) a laminar model and (2) a model with two-dimensional (2D) turbulent mixing. We find that the radial outward increase of the H 2 O D/H ratio is shallower in the chemodynamical nebular model than in the laminar model. This is related to more efficient defractionation of HDO via rapid gas-phase processes because the 2D mixing model allows the water ice to be transported either inward and thermally evaporated or upward and photodesorbed. The laminar model shows the Earth water D/H ratio at r ≲ 2.5 AU, whereas for the 2D chemodynamical model this zone is larger, r ≲ 9 AU. Similarly, the water D/H ratios representative of the Oort-family comets, ∼2.5-10 × 10 –4 , are achieved within ∼2-6 AU and ∼2-20 AU in the laminar and the 2D model, respectively. We find that with regards to the water isotopic composition and the origin of the comets, the mixing model seems to be favored over the laminar model.

14 and Younger: The Sexual Behavior of Young Adolescents. Summary.

Science.gov (United States)

Albert, Bill, Ed.; Brown, Sarah, Ed.; Flanigan, Christine M., Ed.

This summary presents data from seven papers based on six different data sets (three national and three local). Data were collected for different purposes, in different years and places, using different interview techniques. Overall, nearly one in five adolescents has had sex before his/her 15th birthday. In early adolescence, being sexually…

A review of the US Global Change Research Program and NASA's Mission to Planet Earth/Earth Observing System

Science.gov (United States)

Moore, Berrien, III; Anderson, James G.; Costanza, Robert; Gates, W. Lawrence; Grew, Priscilla C.; Leinen, Margaret S.; Mayewski, Paul A.; McCarthy, James J.; Sellers, Piers J.

1995-01-01

This report reflects the results of a ten-day workshop convened at the Scripps Institution of Oceanography July 19-28, 1995. The workshop was convened as the first phase of a two part review of the U.S. Global Change Research Program (USGCRP). The workshop was organized to provide a review of the scientific foundations and progress to date in the USGCRP and an assessment of the implications of new scientific insights for future USGCRP and Mission to Planet Earth/Earth Observing System (MTPE/EOS) activities; a review of the role of NASA's MTPE/EOS program in the USGCRP observational strategy; a review of the EOS Data and Information System (EOSDIS) as a component of USGCRP data management activities; and an assessment of whether recent developments in the following areas lead to a need to readjust MTPE/EOS plans. Specific consideration was given to: proposed convergence of U.S. environmental satellite systems and programs, evolving international plans for Earth observation systems, advances in technology, and potential expansion of the role of the private sector. The present report summarizes the findings and recommendations developed by the Committee on Global Change Research on the basis of the presentations, background materials, working group deliberations, and plenary discussions of the workshop. In addition, the appendices include summaries prepared by the six working groups convened in the course of the workshop.

Earth's Coming of Age: Isotopically Tracking the Global Transformation from the Hadean to the Geologically Modern Earth

Science.gov (United States)

Bennett, V. C.; Nutman, A. P.

2017-12-01

Some of the strongest direct evidence that documents fundamental changes in the chemistry and organisation of Earth's interior derives from radiogenic isotopic compositions that include both long-lived (particularly 176Lu-176Hf and 147Sm-143Nd) and short-lived, i.e., now extinct parent isotope, systems (182Hf-182W, 146Sm-142Nd). Changes in patterns of isotopic evolution are linked to changes in mantle dynamics such that tracking these signatures in geologically well-characterised rocks can be used to discover the the nature and evolution of tectonic processes. Over the past decade, intensive geochemical investigations by various groups focussing on the oldest (> 4.0 Ga to 3.6 Ga) rock record, as preserved in several localities, have revealed isotopic distinctions in the early Earth compared with those in Proterozoic and younger rocks. For example, whilst the major and trace element compositions of Eoarchean gneisses have analogs in younger rocks in accord with a continuum of crust formation processes, radiogenic isotopic signatures from both long and short half-life decay schemes record an image of the Earth in transition from early differentiation processes, likely associated with planetary accretion and formation, to more modern style characterised by plate tectonics. The emerging image is that many Eoarchean rocks possess extinct nuclide anomalies in the form of 142Nd and 182Hf isotopic signatures that are absent in modern terrestrial samples; these signatures are evidence of chemical fractionation processes occuring within the first ca. 10-300 million years of Solar System history. In addition, viewing the global database, patterns of long-half life isotope signatures i.e., 143Nd and 176Hf differ from those seen in younger (modern Earth.

On the paleo-magnetospheres of Earth and Mars

Science.gov (United States)

Scherf, Manuel; Khodachenko, Maxim; Alexeev, Igor; Belenkaya, Elena; Blokhina, Marina; Johnstone, Colin; Tarduno, John; Lammer, Helmut; Tu, Lin; Guedel, Manuel

2017-04-01

The intrinsic magnetic field of a terrestrial planet is considered to be an important factor for the evolution of terrestrial atmospheres. This is in particular relevant for early stages of the solar system, in which the solar wind as well as the EUV flux from the young Sun were significantly stronger than at present-day. We therefore will present simulations of the paleo-magnetospheres of ancient Earth and Mars, which were performed for ˜4.1 billion years ago, i.e. the Earth's late Hadean eon and Mars' early Noachian. These simulations were performed with specifically adapted versions of the Paraboloid Magnetospheric Model (PMM) of the Skobeltsyn Institute of Nuclear Physics of the Moscow State University, which serves as ISO-standard for the Earth's magnetic field (see e.g. Alexeev et al., 2003). One of the input parameters into our model is the ancient solar wind pressure. This is derived from a newly developed solar/stellar wind evolution model, which is strongly dependent on the initial rotation rate of the early Sun (Johnstone et al., 2015). Another input parameter is the ancient magnetic dipole field. In case of Earth this is derived from measurements of the paleomagnetic field strength by Tarduno et al., 2015. These data from zircons are varying between 0.12 and 1.0 of today's magnetic field strength. For Mars the ancient magnetic field is derived from the remanent magnetization in the Martian crust as measured by the Mars Global Surveyor MAG/ER experiment. These data together with dynamo theory are indicating an ancient Martian dipole field strength in the range of 0.1 to 1.0 of the present-day terrestrial dipole field. For the Earth our simulations show that the paleo-magnetosphere during the late Hadean eon was significantly smaller than today, with a standoff-distance rs ranging from ˜3.4 to 8 Re, depending on the input parameters. These results also have implications for the early terrestrial atmosphere. Due to the significantly higher EUV flux, the

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 118; Issue 3 ... demand and also to formulate future development and management strategies. ... gives an early signal of deterioration in groundwater quality in the peripheral parts of ...

NASA's Earth science flight program status

Science.gov (United States)

Neeck, Steven P.; Volz, Stephen M.

2010-10-01

NASA's strategic goal to "advance scientific understanding of the changing Earth system to meet societal needs" continues the agency's legacy of expanding human knowledge of the Earth through space activities, as mandated by the National Aeronautics and Space Act of 1958. Over the past 50 years, NASA has been the world leader in developing space-based Earth observing systems and capabilities that have fundamentally changed our view of our planet and have defined Earth system science. The U.S. National Research Council report "Earth Observations from Space: The First 50 Years of Scientific Achievements" published in 2008 by the National Academy of Sciences articulates those key achievements and the evolution of the space observing capabilities, looking forward to growing potential to address Earth science questions and enable an abundance of practical applications. NASA's Earth science program is an end-to-end one that encompasses the development of observational techniques and the instrument technology needed to implement them. This includes laboratory testing and demonstration from surface, airborne, or space-based platforms; research to increase basic process knowledge; incorporation of results into complex computational models to more fully characterize the present state and future evolution of the Earth system; and development of partnerships with national and international organizations that can use the generated information in environmental forecasting and in policy, business, and management decisions. Currently, NASA's Earth Science Division (ESD) has 14 operating Earth science space missions with 6 in development and 18 under study or in technology risk reduction. Two Tier 2 Decadal Survey climate-focused missions, Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) and Surface Water and Ocean Topography (SWOT), have been identified in conjunction with the U.S. Global Change Research Program and initiated for launch in the 2019

Gradual linguistic summaries

NARCIS (Netherlands)

Wilbik, A.M.; Kaymak, U.; Laurent, A.; Strauss, O.; Bouchon-Meunier, xx

2014-01-01

In this paper we propose a new type of protoform-based linguistic summary – the gradual summary. This new type of summaries aims in capturing the change over some time span. Such summaries can be useful in many domains, for instance in economics, e.g., "prices of X are getting smaller" in eldercare,

Venus and the Archean Earth: Thermal considerations

International Nuclear Information System (INIS)

Sleep, N.H.

1989-01-01

The Archean Era of the Earth is not a direct analog of the present tectonics of Venus. In this regard, it is useful to review the state of the Archean Earth. Most significantly, the temperature of the adiabatic interior of the Earth was 200 to 300 C hotter than the current temperature. Preservation biases limit what can be learned from the Archean record. Archean oceanic crust, most of the planetary surface at any one time, has been nearly all subducted. More speculatively, the core of the Earth has probably cooled more slowly than the mantle. Thus the temperature contrast above the core-mantle boundary and the vigor of mantle plumes has increased with time on the Earth. The most obvious difference between Venus and the present Earth is the high surface temperature and hence a low effective viscosity of the lithosphere. In addition, the temperature contrast between the adiabatic interior and the surface, which drives convection, is less on Venus than on the Earth. It appears that the hot lithosphere enhanced tectonics on the early Venus significantly enough that its interior cooled faster than the Earth's. The best evidence for a cool interior of Venus comes from long wavelength gravity anomalies. The low interior temperatures retard seafloor spreading on Venus. The high surface temperatures on Venus enhance crustal deformation. That is, the lower crust may become ductile enough to permit significant flow between the upper crust and the mantle. There is thus some analogy to modern and ancient areas of high heat flow on the Earth. Archean crustal blocks typically remained stable for long intervals and thus overall are not good analogies to the deformation style on Venus

The fascination of the rare earths - then, now and in the future

International Nuclear Information System (INIS)

Wybourne, Brian G.

2004-01-01

The rare earths have long been a subject of fascination to chemists and physicists. Herein, I comment on some of the prehistory leading up to the advent of the Judd-Ofelt theory of the intensities of their remarkable spectra, the origins of the Judd-Ofelt theory and its early applications. I then consider subsequent developments and extensions of the theory, its current status and its relevance to current problems of interest in rare earth spectroscopy and the future of rare earth studies

Emergence of silicic continents as the lower crust peels off on a hot plate-tectonic Earth

Science.gov (United States)

Chowdhury, Priyadarshi; Gerya, Taras; Chakraborty, Sumit

2017-09-01

The rock record and geochemical evidence indicate that continental recycling has been occurring since the early history of the Earth. The stabilization of felsic continents in place of Earth's early mafic crust about 3.0 to 2.0 billion years ago, perhaps due to the initiation of plate tectonics, implies widespread destruction of mafic crust during this time interval. However, the physical mechanisms of such intense recycling on a hotter, (late) Archaean and presumably plate-tectonic Earth remain largely unknown. Here we use thermomechanical modelling to show that extensive recycling via lower crustal peeling-off (delamination but not eclogitic dripping) during continent-continent convergence was near ubiquitous during the late Archaean to early Proterozoic. We propose that such destruction of the early mafic crust, together with felsic magmatism, may have caused both the emergence of silicic continents and their subsequent isostatic rise, possibly above the sea level. Such changes in the continental character have been proposed to influence the Great Oxidation Event and, therefore, peeling-off plate tectonics could be the geodynamic trigger for this event. A transition to the slab break-off controlled syn-orogenic recycling occurred as the Earth aged and cooled, leading to reduced recycling and enhanced preservation of the continental crust of present-day composition.

Astrobiology: Life on Earth (and Elsewhere?)

Science.gov (United States)

Des Marais, David J.

2016-01-01

Astrobiology investigates the origins, evolution and distribution of life in the universe. Scientists study how stellar systems and their planets can create planetary environments that sustain biospheres. They search for biosignatures, which are objects, substances and or patterns that indicate the presence of life. Studies of Earth's early biosphere enhance these search strategies and also provide key insights about our own origins.

Formation of the Lunar Fossil Bulges and Its Implication for the Early Earth and Moon

Science.gov (United States)

Qin, Chuan; Zhong, Shijie; Phillips, Roger

2018-02-01

First recognized by Laplace over two centuries ago, the Moon's present tidal-rotational bulges are significantly larger than hydrostatic predictions. They are likely relics of a former hydrostatic state when the Moon was closer to the Earth and had larger bulges, and they were established when stresses in a thickening lunar lithosphere could maintain the bulges against hydrostatic adjustment. We formulate the first dynamically self-consistent model of this process and show that bulge formation is controlled by the relative timing of lithosphere thickening and lunar orbit recession. Viable solutions indicate that lunar bulge formation was a geologically slow process lasting several hundred million years, that the process was complete about 4 Ga when the Moon-Earth distance was less than 32 Earth radii, and that the Earth in Hadean was significantly less dissipative to lunar tides than during the last 4 Gyr, possibly implying a frozen hydrosphere due to the fainter young Sun.

Water in the Earth's Interior: Distribution and Origin

Science.gov (United States)

Peslier, Anne H.; Schönbächler, Maria; Busemann, Henner; Karato, Shun-Ichiro

2017-10-01

The concentration and distribution of water in the Earth has influenced its evolution throughout its history. Even at the trace levels contained in the planet's deep interior (mantle and core), water affects Earth's thermal, deformational, melting, electrical and seismic properties, that control differentiation, plate tectonics and volcanism. These in turn influenced the development of Earth's atmosphere, oceans, and life. In addition to the ubiquitous presence of water in the hydrosphere, most of Earth's "water" actually occurs as trace amounts of hydrogen incorporated in the rock-forming silicate minerals that constitute the planet's crust and mantle, and may also be stored in the metallic core. The heterogeneous distribution of water in the Earth is the result of early planetary differentiation into crust, mantle and core, followed by remixing of lithosphere into the mantle after plate-tectonics started. The Earth's total water content is estimated at 18_{-15}^{+81} times the equivalent mass of the oceans (or a concentration of 3900_{-3300}^{+32700} ppm weight H2O). Uncertainties in this estimate arise primarily from the less-well-known concentrations for the lower mantle and core, since samples for water analyses are only available from the crust, the upper mantle and very rarely from the mantle transition zone (410-670 km depth). For the lower mantle (670-2900 km) and core (2900-4500 km), the estimates rely on laboratory experiments and indirect geophysical techniques (electrical conductivity and seismology). The Earth's accretion likely started relatively dry because it mainly acquired material from the inner part of the proto-planetary disk, where temperatures were too high for the formation and accretion of water ice. Combined evidence from several radionuclide systems (Pd-Ag, Mn-Cr, Rb-Sr, U-Pb) suggests that water was not incorporated in the Earth in significant quantities until the planet had grown to ˜60-90% of its current size, while core formation

In Brief: European Earth science network for postdocs

Science.gov (United States)

Showstack, Randy

2008-12-01

The European Space Agency (ESA) has launched a new initiative called the Changing Earth Science Network, to support young scientists undertaking leading-edge research activities aimed at advancing the understanding of the Earth system. The initiative will enable up to 10 young postdoctoral researchers from the agency's member states to address major scientific challenges by using Earth observation (EO) satellite data from ESA and its third-party missions. The initiative aims to foster the development of a network of young scientists in Europe with a good knowledge of the agency and its EO programs. Selected candidates will have the option to carry out part of their research in an ESA center as a visiting scientist. The deadline to submit proposals is 16 January 2009. Selections will be announced in early 2009. The Changing Earth Science Network was developed as one of the main programmatic components of ESA's Support to Science Element, launched in 2008. For more information, visit http://www.esa.int/stse.

Capturing asteroids into bound orbits around the earth: Massive early return on an asteroid terminal defense system

International Nuclear Information System (INIS)

Hills, J.G.

1992-01-01

Nuclear explosives may be used to capture small asteroids (e.g., 20--50 meters in diameter) into bound orbits around the earth. The captured objects could be used for construction material for manned and unmanned activity in Earth orbit. Asteroids with small approach velocities, which are the ones most likely to have close approaches to the Earth, require the least energy for capture. They are particularly easy to capture if they pass within one Earth radius of the surface of the Earth. They could be intercepted with intercontinental missiles if the latter were retrofit with a more flexible guiding and homing capability. This asteroid capture-defense system could be implemented in a few years at low cost by using decommissioned ICMs. The economic value of even one captured asteroid is many times the initial investment. The asteroid capture system would be an essential part of the learning curve for dealing with larger asteroids that can hit the earth

Pisolithus tinctorius, Fungal Extremophile and Modern Analog to an Early Earth Environment; An Unlikely Harbor for Deeply Diverging and Novel Chemoautrophic Microbes

Science.gov (United States)

Cullings, K. C.; Lauzon, C.; Marinkovich, N.; Truong, T.

2014-12-01

Endosymbioses have given rise to some of the most important innovations in Earth's history. Indeed, ecological facilitation has been pivotal to the creation of higher order complexity, and in driving evolutionary transitions at every level of organization from cellular organelles to multicellularity. In this study we address a newly discovered endosymbiosis between prokaryotes and a eukaryote growing with no apparent external energy source in soils associated with acid-sulfate hydrothermal springs. Hydrothermal sites are relevant to origin of life because they provide a chemical and energetic environment that may have provided energy for pre-biotic synthesis in the absence of photosynthesis through chemoautotrophy. Pisolithus (genus, picture 1 below) is a terrestrial fungal extremophile that can grow in thermally altered soils of acid-thermal hot springs at extreme low pH and elevated temperature, thriving in conditions that are beyond the threshold of survivability for most other organisms. Fruiting bodies of this fungus accumulate elemental sulfur into the spore producing tissues (gleba) of the fruiting body. The gleba is encased in a thick peridium, or shell. Further, Pisolithus is capable of enzymatic conversion of elemental S to sulfate. The fruiting bodies are rich in hydrocarbons, contain water through much of their development and are also likely to contain CO2 from fungal cellular respiration. Further, our data indicate the presence of anaerobic zones within. Thus, the internal environment of Pisolithus contains many conditions relevant to early Earth environments in which life is thought to have originated. We used 16S rDNA sequences to test the hypothesis that Pisolithus individuals contain novel and/or ancient microbial lineages. Our data reveal lineages comprised of novel relatives of known aerobic and anaerobic chemoautrophic Bacteria (85-90% BLAST search matches), several deeply divergent and novel Bacterial lineages, and a newly discovered lineage

False Negatives for Remote Life Detection on Ocean-Bearing Planets: Lessons from the Early Earth.

Science.gov (United States)

Reinhard, Christopher T; Olson, Stephanie L; Schwieterman, Edward W; Lyons, Timothy W

2017-04-01

Ocean-atmosphere chemistry on Earth has undergone dramatic evolutionary changes throughout its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has centered on refining our understanding of false positives for remote life detection, much less attention has been paid to the possibility of false negatives, that is, cryptic biospheres that are widespread and active on a planet's surface but are ultimately undetectable or difficult to detect in the composition of a planet's atmosphere. Here, we summarize recent developments from geochemical proxy records and Earth system models that provide insight into the long-term evolution of the most readily detectable potential biosignature gases on Earth-oxygen (O 2 ), ozone (O 3 ), and methane (CH 4 ). We suggest that the canonical O 2 -CH 4 disequilibrium biosignature would perhaps have been challenging to detect remotely during Earth's ∼4.5-billion-year history and that in general atmospheric O 2 /O 3 levels have been a poor proxy for the presence of Earth's biosphere for all but the last ∼500 million years. We further suggest that detecting atmospheric CH 4 would have been problematic for most of the last ∼2.5 billion years of Earth's history. More broadly, we stress that internal oceanic recycling of biosignature gases will often render surface biospheres on ocean-bearing silicate worlds cryptic, with the implication that the planets most conducive to the development and maintenance of a pervasive biosphere will often be challenging to characterize via conventional atmospheric biosignatures. Key Words: Biosignatures-Oxygen-Methane-Ozone-Exoplanets-Planetary habitability. Astrobiology 17, 287-297.

The twin sister planets Venus and Earth why are they so different?

CERN Document Server

Malcuit, Robert J

2014-01-01

This book explains how it came to be that Venus and Earth, while very similar in chemical composition, zonation, size and heliocentric distance from the Sun, are very different in surface environmental conditions. It is argued here that these differences can be accounted for by planetoid capture processes and the subsequent evolution of the planet-satellite system. Venus captured a one-half moon-mass planetoid early in its history in the retrograde direction and underwent its "fatal attraction scenario" with its satellite (Adonis). Earth, on the other hand, captured a moon-mass planetoid (Luna) early in its history in prograde orbit and underwent a benign estrangement scenario with its captured satellite.

Bioremediation at a global scale: from the test tube to planet Earth

OpenAIRE

de Lorenzo, V?ctor; Marli?re, Philippe; Sol?, Ricard

2016-01-01

Summary Planet Earth's biosphere has evolved over billions of years as a balanced bio?geological system ultimately sustained by sunpower and the large?scale cycling of elements largely run by the global environmental microbiome. Humans have been part of this picture for much of their existence. But the industrial revolution started in the XIX century and the subsequent advances in medicine, chemistry, agriculture and communications have impacted such balances to an unprecedented degree ? and ...

Earth mortars and earth-lime renders

Directory of Open Access Journals (Sweden)

Maria Fernandes

2008-01-01

Full Text Available Earth surface coatings play a decorative architectural role, apart from their function as wall protection. In Portuguese vernacular architecture, earth mortars were usually applied on stone masonry, while earth renders and plasters were used on indoors surface coatings. Limestone exists only in certain areas of the country and consequently lime was not easily available everywhere, especially on granite and schist regions where stone masonry was a current building technique. In the central west coast of Portugal, the lime slaking procedure entailed slaking the quicklime mixed with earth (sandy soil, in a pit; the resulting mixture would then be combined in a mortar or plaster. This was also the procedure for manufactured adobes stabilized with lime. Adobe buildings with earth-lime renderings and plasters were also traditional in the same region, using lime putty and lime wash for final coat and decoration. Classic decoration on earth architecture from the 18th-19th century was in many countries a consequence of the François Cointeraux (1740-1830 manuals - Les Cahiers d'Architecture Rurale" (1793 - a French guide for earth architecture and building construction. This manual arrived to Portugal in the beginning of XIX century, but was never translated to Portuguese. References about decoration for earth houses were explained on this manual, as well as procedures about earth-lime renders and ornamentation of earth walls; in fact, these procedures are exactly the same as the ones used in adobe buildings in this Portuguese region. The specific purpose of the present paper is to show some cases of earth mortars, renders and plasters on stone buildings in Portugal and to explain the methods of producing earth-lime renders, and also to show some examples of rendering and coating with earth-lime in Portuguese adobe vernacular architecture.

Reactions between olivine and CO2-rich seawater at 300 °C: Implications for H2 generation and CO2 sequestration on the early Earth

Directory of Open Access Journals (Sweden)

Hisahiro Ueda

2017-03-01

Full Text Available To understand the influence of fluid CO2 on ultramafic rock-hosted seafloor hydrothermal systems on the early Earth, we monitored the reaction between San Carlos olivine and a CO2-rich NaCl fluid at 300 °C and 500 bars. During the experiments, the total carbonic acid concentration (ΣCO2 in the fluid decreased from approximately 65 to 9 mmol/kg. Carbonate minerals, magnesite, and subordinate amount of dolomite were formed via the water-rock interaction. The H2 concentration in the fluid reached approximately 39 mmol/kg within 2736 h, which is relatively lower than the concentration generated by the reaction between olivine and a CO2-free NaCl solution at the same temperature. As seen in previous hydrothermal experiments using komatiite, ferrous iron incorporation into Mg-bearing carbonate minerals likely limited iron oxidation in the fluids and the resulting H2 generation during the olivine alteration. Considering carbonate mineralogy over the temperature range of natural hydrothermal fields, H2 generation is likely suppressed at temperatures below approximately 300 °C due to the formation of the Mg-bearing carbonates. Nevertheless, H2 concentration in fluid at 300 °C could be still high due to the temperature dependency of magnetite stability in ultramafic systems. Moreover, the Mg-bearing carbonates may play a key role in the ocean-atmosphere system on the early Earth. Recent studies suggest that the subduction of carbonated ultramafic rocks may transport surface CO2 species into the deep mantle. This process may have reduced the huge initial amount of CO2 on the surface of the early Earth. Our approximate calculations demonstrate that the subduction of the Mg-bearing carbonates formed in komatiite likely played a crucial role as one of the CO2 carriers from the surface to the deep mantle, even in hot subduction zones.

The Mission Accessibility of Near-Earth Asteroids

Science.gov (United States)

Barbee, Brent W.; Abell, P. A.; Adamo, D. R.; Mazanek, D. D.; Johnson, L. N.; Yeomans, D. K.; Chodas, P. W.; Chamberlin, A. B.; Benner, L. A. M.; Taylor, P.;

Isotopes as clues to the origin and earliest differentiation history of the Earth.

Science.gov (United States)

Jacobsen, Stein B; Ranen, Michael C; Petaev, Michael I; Remo, John L; O'Connell, Richard J; Sasselov, Dimitar D

2008-11-28

Measurable variations in (182)W/(183)W, (142)Nd/(144)Nd, (129)Xe/(130)Xe and (136)XePu/(130)Xe in the Earth and meteorites provide a record of accretion and formation of the core, early crust and atmosphere. These variations are due to the decay of the now extinct nuclides (182)Hf, (146)Sm, (129)I and (244)Pu. The (l82)Hf-(182)W system is the best accretion and core-formation chronometer, which yields a mean time of Earth's formation of 10Myr, and a total time scale of 30Myr. New laser shock data at conditions comparable with those in the Earth's deep mantle subsequent to the giant Moon-forming impact suggest that metal-silicate equilibration was rapid enough for the Hf-W chronometer to reliably record this time scale. The coupled (146)Sm-(147)Sm chronometer is the best system for determining the initial silicate differentiation (magma ocean crystallization and proto-crust formation), which took place at ca 4.47Ga or perhaps even earlier. The presence of a large (129)Xe excess in the deep Earth is consistent with a very early atmosphere formation (as early as 30Myr); however, the interpretation is complicated by the fact that most of the atmospheric Xe may be from a volatile-rich late veneer.

NASA's Upper Atmosphere Research Program UARP and Atmospheric Chemistry Modeling and Analysis Program (ACMAP): Research Summaries 1994 - 1996. Report to Congress and the Environmental Protection Agency

Science.gov (United States)

Kendall, Rose (Compiler); Wolfe, Kathy (Compiler)

1997-01-01

Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology, and monitoring of the Earth's upper atmosphere, with emphasis on the stratosphere. This program aims at expanding our understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Science Division in the Office of Mission to Planet Earth at NASA. Significant contributions to this effort are also provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aeronautics. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper atmosphere and their effect on the distribution of chemical species in the stratosphere, such as ozone; understand the relationship of the trace constituent composition of the lower stratosphere and the lower troposphere to the radiative balance and temperature distribution of the Earth's atmosphere; and accurately assess possible perturbations of the upper atmosphere caused by human activities as well as by natural phenomena. In compliance with the Clean Air Act Amendments of 1990, Public Law 101-549, NASA has prepared a report on the state of our knowledge of the Earth's upper atmosphere, particularly the stratosphere, and on the progress of UARP and ACMAP. The report for the year 1996 is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported under NASA UARP and ACMAP in a document entitled, Research Summary 1994-1996. Part 2 is entitled Present State of Knowledge of the Upper Atmosphere

History of satellite missions and measurements of the Earth Radiation Budget (1957-1984)

Science.gov (United States)

House, F. B.; Gruber, A.; Hunt, G. E.; Mecherikunnel, A. T.

1986-01-01

The history of satellite missions and their measurements of the earth radiation budget from the beginning of the space age until the present time are reviewed. The survey emphasizes the early struggle to develop instrument systems to monitor reflected shortwave and emitted long-wave exitances from the earth, and the problems associated with the interpretation of these observations from space. In some instances, valuable data sets were developed from satellite measurements whose instruments were not specifically designed for earth radiation budget observations.

Summary of the stakeholders workshop to develop a National Volcano Early Warning System (NVEWS)

Science.gov (United States)

Guffanti, Marianne; Scott, William E.; Driedger, Carolyn L.; Ewert, John W.

2006-01-01

The importance of investing in monitoring, mitigation, and preparedness before natural hazards occur has been amply demonstrated by recent disasters such as the Indian Ocean Tsunami in December 2004 and Hurricane Katrina in August 2005. Playing catch-up with hazardous natural phenomena such as these limits our ability to work with public officials and the public to lessen adverse impacts. With respect to volcanic activity, the starting point of effective pre-event mitigation is monitoring capability sufficient to detect and diagnose precursory unrest so that communities at risk have reliable information and sufficient time to respond to hazards with which they may be confronted. Recognizing that many potentially dangerous U.S. volcanoes have inadequate or no ground-based monitoring, the U.S Geological Survey (USGS) Volcano Hazards Program (VHP) and partners recently evaluated U.S. volcano-monitoring capabilities and published 'An Assessment of Volcanic Threat and Monitoring Capabilities in the United States: Framework for a National Volcano Early Warning System (NVEWS).' Results of the NVEWS volcanic threat and monitoring assessment are being used to guide long-term improvements to the national volcano-monitoring infrastructure operated by the USGS and affiliated groups. The NVEWS report identified the need to convene a workshop of a broad group of stakeholders--such as representatives of emergency- and land-management agencies at the Federal, State, and local levels and the aviation sector--to solicit input about implementation of NVEWS and their specific information requirements. Accordingly, an NVEWS Stakeholders Workshop was held in Portland, Oregon, on 22-23 February 2006. A summary of the workshop is presented in this document.

Geological research on rare earth elements, results and outlook

International Nuclear Information System (INIS)

Fortin, H

1999-01-01

This is a report of the geological investigation of rare earth elements carried out by CCHEN and ENAMI (Empresa Nacional de Mineria) over 70,000 square kilometers in Chile's northern coastal mountain range. Twenty areas were identified with sphena, davidite, ilmenite, pyroxene, anatase and magnetite minerals containing 0.3 kg/t to 6.0 kg/t of rare earth elements. Additional research on Cerro Carmen Prospect, located near Diego de Almagro, define it as a metasomatic deposit, hosted in metamorphic contact rocks, between andesites (Pliensbachian to early Jurassic) and intrusive monzonitic rocks. This information increases knowledge about the metallogenesis of Chile's copper - iron - rare earth - uranium deposits and the application of this geological model of ore deposits as defined in Australia's Olympic Dam

KBS Technical report 1-120 (1977-1978). Summaries

International Nuclear Information System (INIS)

1979-05-01

The Swedish nuclear utilities started early in 1977 the KBS (nuclear fuel safety) project to study the high level waste problem and report on how and where a safe final storage could be arranged in Sweden. The docummentation produced by the project during 1977 and 1978 has been collected in a series of technical reports numbered from 1 to 120. The English summaries of the technical reports have been collected in this separate volume, No. 121. (G.B.)

Aqueous magnesium as an environmental selection pressure in the evolution of phospholipid membranes on early earth

Science.gov (United States)

Dalai, Punam; Ustriyana, Putu; Sahai, Nita

2018-02-01

Early compartmentalization of simple biomolecules by membrane bilayers was, presumably, a critical step in the emergence of the first cell-like entities, protocells. Their membranes were likely composed of single chain amphiphiles (SCAs), but pure SCA membranes especially those with short-chains are highly unstable towards divalent cations, which are ubiquitous in aqueous environments. The prebiotic synthesis of phospholipids (PLs), even in only trace amounts, may also have been possible. PL membranes are much more stable towards divalent cations. Here, we show the transition of fatty acid membranes to mixed fatty acid-PL and, finally, to PL membranes in the presence of Mg2+, which acts as an environmental selection pressure, and we propose different mechanisms for the observed increased Mg2+-immunity. The "fatal" concentration ([Mg2+]fatal) at which vesicles are disrupted increased dramatically by an order of magnitude from OA to mixed to POPC vesicles. Two mechanisms for the increasing immunity were determined. The negative charge density of the vesicles decreased with increasing POPC content, so more Mg2+ was required for disruption. More interestingly, Mg2+ preferentially bound to and abstracted OA from mixed lipid membranes, resulting in relatively POPC-enriched vesicles compared to the initial ratio. The effect was the most dramatic for the largest initial OA-POPC ratio representing the most primitive protocells. Thus, Mg2+ acted to evolve the mixed membrane composition towards PL enrichment. To the best of our knowledge, this is the first report of selective lipid abstraction from mixed SCA-PL vesicles. These results may hold implications for accommodating prebiotic Mg2+-promoted processes such as non-enzymatic RNA polymerization on early Earth.

Earth Observations for Early Detection of Agricultural Drought in Countries at Risk: Contributions of the Famine Early Warning Systems Network (FEWS NET) (Invited)

Science.gov (United States)

Verdin, J. P.; Rowland, J.; Senay, G. B.; Funk, C. C.; Budde, M. E.; Husak, G. J.; Jayanthi, H.

2013-12-01

The Group on Earth Observations' Global Agricultural Monitoring (GEOGLAM) implementation plan emphasizes the information needs of countries at risk of food insecurity emergencies. Countries in this category are often vulnerable to disruption of agricultural production due to drought, while at the same time they lack well developed networks of in-situ observations to support early drought detection. Consequently, it is vital that Earth observations by satellites supplement those available from surface stations. The USGS, in its role as a FEWS NET implementing partner, has recently developed a number of new applications of satellite observations for this purpose. (1) In partnership with the University of California, Santa Barbara, a 30+ year time series of gridded precipitation estimates (CHIRPS) has been developed by blending NOAA GridSat B1 geostationary thermal infrared imagery with station observations using robust geostatistical methods. The core data set consists of pentadal (5-daily) accumulations from 1981-2013 at 0.05 degree spatial resolution between +/- 50 degrees latitude. Validation has been recently completed, and applications for gridded crop water balance calculations and mapping the Standardized Precipitation Index are in development. (2) Actual evapotranspiration (ETa) estimates using MODIS Land Surface Temperature (LST) data at 1-km have been successfully demonstrated using the operational Simplified Surface Energy Balance model with 8-day composites from the LPDAAC. A new, next-day latency implementation using daily LST swath data from the NASA LANCE server is in development for all the crop growing regions of the world. This ETa processing chain follows in the footsteps of (3) the expedited production of MODIS 250-meter NDVI images every five days at USGS EROS, likewise using LANCE daily swath data as input since 2010. Coverage includes Africa, Central Asia, the Middle East, Central America, and the Caribbean. (4) A surface water point monitoring

Predictions of asteroid hazard to the Earth for the 21st century

Science.gov (United States)

Petrov, Nikita; Sokolov, Leonid; Polyakhova, Elena; Oskina, Kristina

2018-05-01

Early detection and investigation of possible collisions and close approaches of asteroids with the Earth are necessary to exept the asteroid-comet hazard. The difficulty of prediction of close approaches and collisions associated with resonant returns after encounters with the Earth due to loss of precision in these encounters. The main research object is asteroid Apophis (99942), for which we found many possible orbits of impacts associated with resonant returns. It is shown that the early orbit change of Apophis allows to avoid main impacts, associated with resonant returns. Such a change of the orbit, in principle, is feasible. We also study the possible impacts with the Ground asteroid 2015 RN35. We present 21 possible collisions in this century, including 7 collisions with large gaps presented in NASA website. The results of observations by the telescope ZA-320M at Pulkovo Obser-vatory of the three near-Earth asteroids, namely, 7822, 20826, 68216, two of which 7822 and 68216 are potentially hazardous, are presented.

EarthScope Education and Outreach: Accomplishments and Emerging Opportunities

Science.gov (United States)

Robinson, S.; Ellins, K. K.; Semken, S. C.; Arrowsmith, R.

2014-12-01

EarthScope's Education and Outreach (E&O) program aims to increase public awareness of Earth science and enhance geoscience education at the K-12 and college level. The program is distinctive among major geoscience programs in two ways. First, planning for education and public engagement occurred in tandem with planning for the science mission. Second, the NSF EarthScope program includes funding support for education and outreach. In this presentation, we highlight key examples of the program's accomplishments and identify emerging E&O opportunities. E&O efforts have been collaboratively led by the EarthScope National Office (ESNO), IRIS, UNAVCO, the EarthScope Education and Outreach Subcommittee (EEOSC) and PI-driven EarthScope projects. Efforts by the EEOSC, guided by an EarthScope Education and Outreach Implementation Plan that is periodically updated, focus EarthScope E&O. EarthScope demonstrated early success in engaging undergraduate students (and teachers) in its mission through their involvement in siting USArray across the contiguous U.S. Funded E&O programs such as TOTLE, Illinois EarthScope, CEETEP (for K-12), InTeGrate and GETSI (for undergraduates) foster use of freely available EarthScope data and research findings. The Next Generation Science Standards, which stress science and engineering practices, offer an opportunity for alignment with existing EarthScope K-12 educational resources, and the EEOSC recommends focusing efforts on this task. The EEOSC recognizes the rapidly growing use of mobile smart devices by the public and in formal classrooms, which bring new opportunities to connect with the public and students. This will capitalize on EarthScope's already prominent social media presence, an effort that developed to accomplish one of the primary goals of the EarthScope E&O Implementation Plan to "Create a high-profile public identity for EarthScope" and to "Promote science literacy and understanding of EarthScope among all audiences through

Cratering record in the inner solar system: Implications for earth

International Nuclear Information System (INIS)

Barlow, N.G.

1988-01-01

Internal and external processes have reworked the Earth's surface throughout its history. In particular, the effect of meteorite impacts on the early history of the earth is lost due to fluvial, aeolian, volcanic and plate tectonic action. The cratering record on other inner solar system bodies often provides the only clue to the relative cratering rates and intensities that the earth has experienced throughout its history. Of the five major bodies within the inner solar system, Mercury, Mars, and the Moon retain scars of an early episode of high impact rates. The heavily cratered regions on Mercury, Mars, and the Moon show crater size-frequency distribution curves similar in shape and crater density, whereas the lightly cratered plains on the Moon and Mars show distribution curves which, although similar to each other, are statistically different in shape and density from the more heavily cratered units. The similarities among crater size-frequency distribution curves for the Moon, Mercury, and Mars suggest that the entire inner solar system was subjected to the two populations of impacting objects but Earth and Venus have lost their record of heavy bombardment impactors. Thus, based on the cratering record on the Moon, Mercury, and Mars, it can be inferred that the Earth experienced a period of high crater rates and basin formation prior to about 3.8 BY ago. Recent studies have linked mass extinctions to large terrestrial impacts, so life forms were unable to establish themselves until impact rates decreased substantially and terrestrial conditions became more benign. The possible periodicity of mass extinctions has led to the theory of fluctuating impact rates due to comet showers in the post heavy bombardment period. The active erosional environment on the Earth complicates attempts to verify these showers by erasing geological evidence of older impact craters

Characteristics of solar and heliospheric ion populations observed near earth

International Nuclear Information System (INIS)

Gloeckler, G.

1984-01-01

The composition and spectra of ions in solar-energetic-particle and energetic-storm-particle events, of diffuse ions upstream of the earth bow shock, and of ions in deep-geomagnetic-tail plasmoids are characterized in a summary of in situ observations. Data are presented in graphs and tables, and remarkable similarities are noted in the distribution functions of the heliospheric ion populations. The solar wind, acting through acceleration mechanisms associated with shocks and turbulence, is identified as the major plasma source of suprathermal and energetic particles. 33 references

Young Earth System Scientists (YESS) Community

Science.gov (United States)

Reed, K. A.; Langendijk, G.; Bahar, F.; Huang-Lachmann, J. T.; Osman, M.; Mirsafa, M.; Sonntag, S.

2017-12-01

The Young Earth System Scientists (YESS) community is compiled of early career researchers (including students) coming from a range of scientific backgrounds, spanning both natural and social sciences. YESS unifies young researchers in an influential network to give them a collective voice and leverage within the geosciences community, while supporting career development. The YESS community has used its powerful network to provide a unified perspective on the future of Earth system science (Rauser et al. 2017), to be involved in the organization of international conferences, and to engage with existing international structures that coordinate science. Since its founding in Germany in 2010, the YESS community has grown extensively across the globe, with currently almost 1000 members from over 80 countries, and has become truly interdisciplinary. Recently, the organization has carried elections for Regional Representatives and the Executive Committee as part of its self-sustained governance structure. YESS is ready to continue pioneering crucial areas of research which provide solutions to benefit society for the long-term advancement of Earth system science.

Some comments on the requirement for nuclear data in the earth sciences

International Nuclear Information System (INIS)

Clayton, C.G.; Patrick, B.H.; Sanders, L.G.; Sowerby, M.G.

1984-01-01

The increasing application of nuclear techniques in the earth sciences, and especially the use of particle tracking codes, has focussed attention on the need for more accurate nuclear data and for data which particularly refer to elements of interest in the analysis of rocks and ores. The present paper gives a brief summary of the current and potential requirement for nuclear data in nuclear geophysics and an indication of several important areas where better data would be valuable. (author)

Cobalt rare earth permanent magnets (citations from the Engineering Index data base). Final report for 1970--May 1978

International Nuclear Information System (INIS)

Smith, M.F.

1978-06-01

Research summaries from worldwide journals on fabrication, composition, bonding, sintering, pressing, and processing of these magnets are presented. Studies on phase transformations, microstructure, intermetallic compounds, and anisotropy are covered. The efficiency of electric motors, traveling wave tubes, microwave equipment and magnetic tape drives using cobalt rare earth magnets is included

Lunar paleotides and the origin of the earth-moon system

International Nuclear Information System (INIS)

Anderson, A.J.

1978-01-01

A new method for determining the early history of the Earth-Moon system is described. Called the study of lunar paleotides, it describes a method for explaining features of the remnant lunar gravity field, and the generation of the lunar mascons. A method for the determination of Earth-Moon distances compared with the radiometric ages of the maria is developed. It is shown that the Moon underwent strong anomalous gravitational tidal forces, for a duration t 6 yr, prior to the formation of the mascon surfaces. As these tidal forces had not been present at the time of the formation of the Moon, this shows that the Moon could not have been formed in orbit about the Earth. (Auth.)

Thunderstorm activity in early Earth: same estimations from point of view a role of electric discharges in formation of prebiotic conditions

Science.gov (United States)

Serozhkin, Yu.

2008-09-01

Introduction The structure and the physical parameters of an early Earth atmosphere [1], most likely, played a determining role in formation of conditions for origin of life. The estimation of thunderstorm activity in atmosphere of the early Earth is important for understanding of the real role of electrical discharges during formation of biochemical compounds. The terrestrial lightning a long time are considered as one of components determining a physical state and chemical structure of an atmosphere. Liebig in 1827 has considered a capability of nitrogen fixation at discharges of lightning [2]. Recent investigations (Lamarque et al. 1996) have achieved that production rate of NOx due to lightning at 3·106 ton/year [3]. The efficiency of electric discharges as energy source for synthesis of low molecular weight organic compounds is explained by the several factors. To them concern effect of optical radiation, high temperature, shock waves and that is especially important, pulse character of these effects. The impulse impact is essentially reduced the probability of destruction of the formed compounds. However, for some reasons is not clear the real role of electric discharges in synthesis of biochemical compounds. The discharges used in experiments on synthesis of organic substances, do not remind the discharges observable in a nature. One more aspect of a problem about a role of electric discharges in forming pre-biotic conditions on the Earth is connected with the thunderstorm activity in a modern atmosphere. This activity is connected with the presence in an atmosphere of ice crystals and existing gradient of temperature. To tell something about a degree of thunderstorm activity during the early Earth, i.e. that period, when formed pre-biotic conditions were is very difficult. Astrobiological potential of various discharges First of all the diversity of electric discharges in terrestrial atmosphere (usual lightning, lightning at eruption of volcanoes

Deriving Earth Science Data Analytics Requirements

Science.gov (United States)

Kempler, Steven J.

2015-01-01

Data Analytics applications have made successful strides in the business world where co-analyzing extremely large sets of independent variables have proven profitable. Today, most data analytics tools and techniques, sometimes applicable to Earth science, have targeted the business industry. In fact, the literature is nearly absent of discussion about Earth science data analytics. Earth science data analytics (ESDA) is the process of examining large amounts of data from a variety of sources to uncover hidden patterns, unknown correlations, and other useful information. ESDA is most often applied to data preparation, data reduction, and data analysis. Co-analysis of increasing number and volume of Earth science data has become more prevalent ushered by the plethora of Earth science data sources generated by US programs, international programs, field experiments, ground stations, and citizen scientists.Through work associated with the Earth Science Information Partners (ESIP) Federation, ESDA types have been defined in terms of data analytics end goals. Goals of which are very different than those in business, requiring different tools and techniques. A sampling of use cases have been collected and analyzed in terms of data analytics end goal types, volume, specialized processing, and other attributes. The goal of collecting these use cases is to be able to better understand and specify requirements for data analytics tools and techniques yet to be implemented. This presentation will describe the attributes and preliminary findings of ESDA use cases, as well as provide early analysis of data analytics toolstechniques requirements that would support specific ESDA type goals. Representative existing data analytics toolstechniques relevant to ESDA will also be addressed.

Constraining the climate and ocean pH of the early Earth with a geological carbon cycle model.

Science.gov (United States)

Krissansen-Totton, Joshua; Arney, Giada N; Catling, David C

2018-04-17

The early Earth's environment is controversial. Climatic estimates range from hot to glacial, and inferred marine pH spans strongly alkaline to acidic. Better understanding of early climate and ocean chemistry would improve our knowledge of the origin of life and its coevolution with the environment. Here, we use a geological carbon cycle model with ocean chemistry to calculate self-consistent histories of climate and ocean pH. Our carbon cycle model includes an empirically justified temperature and pH dependence of seafloor weathering, allowing the relative importance of continental and seafloor weathering to be evaluated. We find that the Archean climate was likely temperate (0-50 °C) due to the combined negative feedbacks of continental and seafloor weathering. Ocean pH evolves monotonically from [Formula: see text] (2σ) at 4.0 Ga to [Formula: see text] (2σ) at the Archean-Proterozoic boundary, and to [Formula: see text] (2σ) at the Proterozoic-Phanerozoic boundary. This evolution is driven by the secular decline of pCO 2 , which in turn is a consequence of increasing solar luminosity, but is moderated by carbonate alkalinity delivered from continental and seafloor weathering. Archean seafloor weathering may have been a comparable carbon sink to continental weathering, but is less dominant than previously assumed, and would not have induced global glaciation. We show how these conclusions are robust to a wide range of scenarios for continental growth, internal heat flow evolution and outgassing history, greenhouse gas abundances, and changes in the biotic enhancement of weathering. Copyright © 2018 the Author(s). Published by PNAS.

Aqueous corrosion of phosphide minerals from iron meteorites: a highly reactive source of prebiotic phosphorus on the surface of the early Earth.

Science.gov (United States)

Pasek, Matthew A; Lauretta, Dante S

2005-08-01

We present the results of an experimental study of aqueous corrosion of Fe-phosphide under conditions relevant to the early Earth. The results strongly suggest that iron meteorites were an important source of reactive phosphorus (P), a requirement for the formation of P-based life. We further demonstrate that iron meteorites were an abundant source of phosphide minerals early in Earth history. Phosphide corrosion was studied in five different solutions: deionized water, deionized water buffered with sodium bicarbonate, deionized water with dissolved magnesium and calcium chlorides, deionized water containing ethanol and acetic acid, and deionized water containing the chlorides, ethanol, and acetic acid. Experiments were performed in the presence of both air and pure Ar gas to evaluate the effect of atmospheric chemistry. Phosphide corrosion in deionized water results in a metastable mixture of mixed-valence, P-bearing ions including pyrophosphate and triphosphate, key components for metabolism in modern life. In a pH-buffered solution of NaHCO(3), the condensed and reduced species diphosphonate is an abundant corrosion product. Corrosion in ethanol- and acetic acid-containing solutions yields additional P-bearing organic molecules, including acetyl phosphonate and a cyclic triphosphorus molecule. Phosphonate is a major corrosion product of all experiments and is the only P-bearing molecule that persists in solutions with high concentrations of magnesium and calcium chlorides, which suggests that phosphonate may have been a primitive oceanic source of P. The stability and reactivity of phosphonate and hypophosphite in solution were investigated to elucidate reaction mechanisms and the role of mineral catalysts on P-solution chemistry. Phosphonate oxidation is rapid in the presence of Fe metal but negligible in the presence of magnetite and in the control sample. The rate of hypophosphite oxidation is independent of reaction substrate.

DAsHER CD: Developing a Data-Oriented Human-Centric Enterprise Architecture for EarthCube

Science.gov (United States)

Yang, C. P.; Yu, M.; Sun, M.; Qin, H.; Robinson, E.

2015-12-01

One of the biggest challenges that face Earth scientists is the resource discovery, access, and sharing in a desired fashion. EarthCube is targeted to enable geoscientists to address the challenges by fostering community-governed efforts that develop a common cyberinfrastructure for the purpose of collecting, accessing, analyzing, sharing and visualizing all forms of data and related resources, through the use of advanced technological and computational capabilities. Here we design an Enterprise Architecture (EA) for EarthCube to facilitate the knowledge management, communication and human collaboration in pursuit of the unprecedented data sharing across the geosciences. The design results will provide EarthCube a reference framework for developing geoscience cyberinfrastructure collaborated by different stakeholders, and identifying topics which should invoke high interest in the community. The development of this EarthCube EA framework leverages popular frameworks, such as Zachman, Gartner, DoDAF, and FEAF. The science driver of this design is the needs from EarthCube community, including the analyzed user requirements from EarthCube End User Workshop reports and EarthCube working group roadmaps, and feedbacks or comments from scientists obtained by organizing workshops. The final product of this Enterprise Architecture is a four-volume reference document: 1) Volume one is this document and comprises an executive summary of the EarthCube architecture, serving as an overview in the initial phases of architecture development; 2) Volume two is the major body of the design product. It outlines all the architectural design components or viewpoints; 3) Volume three provides taxonomy of the EarthCube enterprise augmented with semantics relations; 4) Volume four describes an example of utilizing this architecture for a geoscience project.

Summary of the Hanford Site Environmental Report for Calendar Year 2009

Energy Technology Data Exchange (ETDEWEB)

Duncan, Joanne P.; Poston, Ted M.; Dirkes, Roger L.

2010-09-30

This summary booklet summarizes the "Hanford Site Environmental Report for Calendar Year 2009." The Hanford Site environmental report, published annually since 1958, includes information and summary data that provide an overview of activities at the U.S. Department of Energy's (DOE) Hanford Site. The Hanford Site environmental report provides an overview of activities at the site; demonstrates the status of the site’s compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and DOE policies and directives; and summarizes environmental data that characterize Hanford Site environmental management performance. The report also highlights significant environmental and public protection programs and efforts. Some historical and early 2010 information is included where appropriate.

Summary of the Hanford Site Environmental Report for Calendar Year 2008

International Nuclear Information System (INIS)

Duncan, Joanne P.; Poston, Ted M.; Dirkes, Roger L.

2009-01-01

This summary booklet summarizes the 'Hanford Site Environmental Report for Calendar Year 2008'. The Hanford Site environmental report, published annually since 1958, includes information and summary data that provide an overview of activities at the U.S. Department of Energy's (DOE) Hanford Site. The Hanford Site environmental report provides an overview of activities at the site; demonstrates the status of the site's compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and DOE policies and directives; and summarizes environmental data that characterize Hanford Site environmental management performance. The report also highlights significant environmental and public protection programs and efforts. Some historical and early 2009 information is included where appropriate.

Zaccaria Lilio and the shape of the earth: A brief response to Allegro's "Flat earth science".

Science.gov (United States)

Nothaft, C Philipp E

2017-12-01

This is a response to James J. Allegro's article "The Bottom of the Universe: Flat Earth Science in the Age of Encounter," published in Volume 55, Number 1, of this journal. Against the solid consensus of modern scholars, Allegro contends that the decades around 1500 saw a resurgence of popular and learned doubts about the existence of a southern hemisphere and the concept of a spherical earth more generally. It can be shown that a substantial part of Allegro's argument rests on an erroneous reading of his main textual witness, Zaccaria Lilio's Contra Antipodes (1496), and on a failure adequately to place this source in the context of the cosmographical debate of the late fifteenth and early sixteenth centuries. Once this context is taken into account, the notion that Lilio was a flat-earther falls flat.

A petrological view of early Earth geodynamics

Science.gov (United States)

Herzberg, C.

2003-04-01

primary magmas contained 14 to 22% MgO, similar to Reykjanes MORB, Gorgona, Hawaii, and the early Icelandic plume in the model of Herzberg & O'Hara (2002). However, a few xenoliths record T_P as low as 1300oC. Two geodynamic interpretations follow: 1) Archean cratonic mantle formed as residues below ridges and hotspots similar to those of today, except the lithosphere was somewhat thinner in some cases, 2) Archean cratonic mantle formed as residues below hot ridges in most cases. Early Proterozoic sheeted dikes and eruptives from the Cape Smith Belt in Canada are consistent with the hot ridge interpretation. Ridge potential temperatures could have been 1520-1570oC, higher than modern ridges (1300-1450oC) but similar to those for the Gorgona and early Tertiary Icelandic plumes.

A basic introduction to the thermodynamics of the Earth system far from equilibrium and maximum entropy production

Science.gov (United States)

Kleidon, A.

2010-01-01

The Earth system is remarkably different from its planetary neighbours in that it shows pronounced, strong global cycling of matter. These global cycles result in the maintenance of a unique thermodynamic state of the Earth's atmosphere which is far from thermodynamic equilibrium (TE). Here, I provide a simple introduction of the thermodynamic basis to understand why Earth system processes operate so far away from TE. I use a simple toy model to illustrate the application of non-equilibrium thermodynamics and to classify applications of the proposed principle of maximum entropy production (MEP) to such processes into three different cases of contrasting flexibility in the boundary conditions. I then provide a brief overview of the different processes within the Earth system that produce entropy, review actual examples of MEP in environmental and ecological systems, and discuss the role of interactions among dissipative processes in making boundary conditions more flexible. I close with a brief summary and conclusion. PMID:20368248

A basic introduction to the thermodynamics of the Earth system far from equilibrium and maximum entropy production.

Science.gov (United States)

Kleidon, A

2010-05-12

The Earth system is remarkably different from its planetary neighbours in that it shows pronounced, strong global cycling of matter. These global cycles result in the maintenance of a unique thermodynamic state of the Earth's atmosphere which is far from thermodynamic equilibrium (TE). Here, I provide a simple introduction of the thermodynamic basis to understand why Earth system processes operate so far away from TE. I use a simple toy model to illustrate the application of non-equilibrium thermodynamics and to classify applications of the proposed principle of maximum entropy production (MEP) to such processes into three different cases of contrasting flexibility in the boundary conditions. I then provide a brief overview of the different processes within the Earth system that produce entropy, review actual examples of MEP in environmental and ecological systems, and discuss the role of interactions among dissipative processes in making boundary conditions more flexible. I close with a brief summary and conclusion.

NASA's Earth Science Flight Program overview

Science.gov (United States)

Neeck, Steven P.; Volz, Stephen M.

2011-11-01

NASA's Earth Science Division (ESD) conducts pioneering work in Earth system science, the interdisciplinary view of Earth that explores the interaction among the atmosphere, oceans, ice sheets, land surface interior, and life itself that has enabled scientists to measure global and climate changes and to inform decisions by governments, organizations, and people in the United States and around the world. The ESD makes the data collected and results generated by its missions accessible to other agencies and organizations to improve the products and services they provide, including air quality indices, disaster management, agricultural yield projections, and aviation safety. In addition to four missions now in development and 14 currently operating on-orbit, the ESD is now developing the first tier of missions recommended by the 2007 Earth Science Decadal Survey and is conducting engineering studies and technology development for the second tier. Furthermore, NASA's ESD is planning implementation of a set of climate continuity missions to assure availability of key data sets needed for climate science and applications. These include a replacement for the Orbiting Carbon Observatory (OCO), OCO-2, planned for launch in 2013; refurbishment of the SAGE III atmospheric chemistry instrument to be hosted by the International Space Station (ISS) as early as 2014; and the Gravity Recovery and Climate Experiment Follow-On (GRACE FO) mission scheduled for launch in 2016. The new Earth Venture (EV) class of missions is a series of uncoupled, low to moderate cost, small to medium-sized, competitively selected, full orbital missions, instruments for orbital missions of opportunity, and sub-orbital projects.

Earth's inner core: Innermost inner core or hemispherical variations?

NARCIS (Netherlands)

Lythgoe, K. H.; Deuss, A.|info:eu-repo/dai/nl/412396610; Rudge, J. F.; Neufeld, J. A.

2014-01-01

The structure of Earth's deep inner core has important implications for core evolution, since it is thought to be related to the early stages of core formation. Previous studies have suggested that there exists an innermost inner core with distinct anisotropy relative to the rest of the inner core.

Summary of the accelerator working group

International Nuclear Information System (INIS)

Ankenbrandt, C.; Noble, R.J.

1998-03-01

We present a summary of the main topics discussed in the Accelerator Working Group during the ''Workshop on the Physics at the First Muon Collider''. The discussions centered on critical design issues for a high-intensity, medium-energy proton synchrotron that would replace the present Fermilab 8 GeV Booster early in the next century. Such a machine is intended both to serve the hadron program with an order of magnitude increase in average proton current and to be compatible as a source for a future muon collider. Particular issues discussed at length include rf system design, control of longitudinal space-charge effects, bunching of proton beams and beam instabilities

Organic Aerosols in the Presence of CO{sub 2} in the Early Earth and Exoplanets: UV–Vis Refractive Indices of Oxidized Tholins

Energy Technology Data Exchange (ETDEWEB)

Gavilan, Lisseth; Carrasco, Nathalie; Vettier, Ludovic [LATMOS, Université Versailles St Quentin, UPMC Université Paris 06, CNRS, 11 blvd d’Alembert, F-78280 Guyancourt (France); Broch, Laurent [LCP-A2MC, Institut Jean Barriol, Université de Lorraine, Metz (France); Fleury, Benjamin, E-mail: lisseth.gavilan@latmos.ipsl.fr [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2017-10-10

In this experimental study we investigate the role of atmospheric CO{sub 2} on the optical properties of organic photochemical aerosols. To this end, we add CO{sub 2} to a N{sub 2}:CH{sub 4} gas mixture used in a plasma typically used for Titan studies. We produce organic thin films (tholins) in plasmas where the CO{sub 2}/CH{sub 4} ratio is increased from 0 to 4. We measure these films via spectrometric ellipsometry and apply a Tauc–Lorentz model, used for optically transparent materials, to obtain the thickness of the thin film, its optical band gap, and the refractive indices in the UV–visible (270–600 nm). All samples present a significant absorption band in the UV. According to the Tauc–Lorentz model, as the CO{sub 2}/CH{sub 4} ratio is quadrupled, the position of the UV band is shifted from ∼177 nm to 264 nm while its strength is quadrupled. Consequently, we infer that oxidized organic aerosols absorb more efficiently at longer UV wavelengths than reduced aerosols. Our laboratory wavelength-tabulated UV–vis refractive indices provide new constraints to atmospheric models of the early Earth and Earth-like exoplanets including photochemical hazes formed under increasingly oxidizing conditions.

The earth’'s electric field sources from sun to mud

CERN Document Server

Kelley, Michael C

2013-01-01

The Earth's Electric Field provides you with an integrated and comprehensive picture of the generation of the terrestrial electric fields, their dynamics and how they couple/propagate through the medium. The Earth's Electric Field provides basic principles of terrestrial electric field related topics, but also a critical summary of electric field related observations and their significance to the various related phenomena in the atmosphere. For the first time, Kelley brings together information on this topic in a coherent way, making it easy to gain a broad overview of the critical processes in an efficient way. If you conduct research in atmospheric science, physics, atmospheric chemistry, space plasma physics, and solar terrestrial physics, you will find this book to be essential reading. The only book on the physics of terrestrial electric fields and their generation mechanisms, propagation and dynamics-making it essential reading for scientists conducting research in upper atmospheric, ionospheric, magnet...

Using GRIDVIEW to Better Understand the Early Bombardment History of the Moon, Mars and Earth

Science.gov (United States)

Frey, Herbert

2012-01-01

) on the Moon (Frey and Burgess, 2012, this meeting), with obvious implications for the early bombardment history of the Earth.

Low earth orbit environmental effects on the space station photovoltaic power generation systems

International Nuclear Information System (INIS)

Nahra, H.K.

1977-01-01

A summary of the Low Earth Orbital Environment, its impact on the photovoltaic power systems of the space station and the solutions implemented to resolve the environmental concerns or issues are described. Low Earth Orbital Environment (LEO) presents several concerns to the photovoltaic power systems of the space station. These concerns include atomic oxygen interaction with the polymeric substrate of the solar arrays, ionized environment effects on the array operating voltage, the effects of the meteoroids and debris impacts and penetration through the different layers of the solar cells and their circuits, and the high energy particle and radiation effects on the overall solar array performance. Potential solutions to some of the degrading environmental interactions that will provide the photovoltaic power system of the space station with the desired life are also summarized

Leveraging Current Initiatives to Bring Earth and Space Science into Elementary and Early Childhood Classrooms: NGSS in the Context of the Classroom Technology Push

Science.gov (United States)

Pacheco-Guffrey, H. A.

2016-12-01

Classroom teachers face many challenges today such as new standards, the moving targets of high stakes tests and teacher evaluations, inconsistent/insufficient access to resources and evolving education policies. Science education in the K-5 context is even more complex. NGSS can be intimidating, especially to K-5 educators with little science background. High stakes science tests are slow to catch up with newly drafted state level science standards, leaving teachers unsure about what to change and when to implement updated standards. Amid all this change, many schools are also piloting new technology programs. Though exciting, tech initiatives can also be overwhelming to teachers who are already overburdened. A practical way to support teachers in science while remaining mindful of these stressors is to design and share resources that leverage other K-5 school initiatives. This is often done by integrating writing or math into science learning to meet Common Core requirements. This presentation will suggest a method for bringing Earth and space science learning into elementary / early childhood classrooms by utilizing the current push for tablet technology. The goal is to make science integration reasonable by linking it to technology programs that are in their early stages. The roles and uses of K-5 Earth and space science apps will be examined in this presentation. These apps will be linked to NGSS standards as well as to the science and engineering practices. To complement the app resources, two support frameworks will also be shared. They are designed to help educators consider new technologies in the context of their own classrooms and lessons. The SAMR Model (Puentadura, 2012) is a conceptual framework that helps teachers think critically about the means and purposes of integrating technology into existing lessons. A practical framework created by the author will also be shared. It is designed to help teachers identify and address the important logistical

Research Summaries

Science.gov (United States)

Brock, Stephen E., Ed.

2011-01-01

This article presents summaries of three articles relevant to school crisis response: (1) "Factors Contributing to Posttraumatic Growth," summarized by Steve DeBlois; (2) "Psychological Debriefing in Cross-Cultural Contexts" (Stacey Rice); and (3) "Brain Abnormalities in PTSD" (Sunny Windingstad). The first summary reports the findings of a…

Rapid sea level rise in the aftermath of a Neoproterozoic snowball Earth.

Science.gov (United States)

Myrow, P M; Lamb, M P; Ewing, R C

2018-04-19

Earth's most severe climate changes occurred during global-scale snowball-Earth glaciations, which profoundly altered Earth's atmosphere, oceans, and biosphere. Extreme rates of glacio-eustatic sea-level rise are a fundamental prediction of the snowball Earth hypothesis, but supporting geologic evidence is lacking. We use paleohydraulic analysis of wave ripples and tidal laminae of the Elatina Formation, Australia - deposited following the Marinoan glaciation ca. 635Ma - to show that water depths of 9-16m remained nearly constant for ~100yrs throughout 27m of sediment accumulation. This accumulation rate was too great to have been accommodated by subsidence, and instead indicates an extraordinarily rapid rate of sea-level rise (0.2-0.27m/yr). Our results substantiate a fundamental prediction of snowball Earth models of rapid deglaciation during the early transition to a super-greenhouse climate. Copyright © 2018, American Association for the Advancement of Science.

Earth's Early Biosphere and the Biogeochemical Carbon Cycle

Science.gov (United States)

DesMarais, David

2004-01-01

Our biosphere has altered the global environment principally by influencing the chemistry of those elements most important for life, e g., C, N, S, O, P and transition metals (e.g., Fe and Mn). The coupling of oxygenic photosynthesis with the burial in sediments of photosynthetic organic matter, and with the escape of H2 to space, has increased the state of oxidation of the Oceans and atmosphere. It has also created highly reduced conditions within sedimentary rocks that have also extensively affected the geochemistry of several elements. The decline of volcanism during Earth's history reduced the flow of reduced chemical species that reacted with photosynthetically produced O2. The long-term net accumulation of photosynthetic O2 via biogeochemical processes has profoundly influenced our atmosphere and biosphere, as evidenced by the O2 levels required for algae, multicellular life and certain modem aerobic bacteria to exist. When our biosphere developed photosynthesis, it tapped into an energy resource that was much larger than the energy available from oxidation-reduction reactions associated with weathering and hydrothermal activity. Today, hydrothermal sources deliver globally (0.13-1.1)x10(exp l2) mol yr(sup -1) of reduced S, Fe(2+), Mn(2+), H2 and CH4; this is estimated to sustain at most about (0.2-2)xl0(exp 12)mol C yr(sup -1) of organic carbon production by chemautotrophic microorganisms. In contrast, global photosynthetic productivity is estimated to be 9000x10(exp 12) mol C yr(sup -1). Thus, even though global thermal fluxes were greater in the distant geologic past than today, the onset of oxygenic photosynthesis probably increased global organic productivity by some two or more orders of magnitude. This enormous productivity materialized principally because oxygenic photosynthesizers unleashed a virtually unlimited supply of reduced H that forever freed life from its sole dependence upon abiotic sources of reducing power such as hydrothermal emanations

A Geological Model for the Evolution of Early Continents (Invited)

Science.gov (United States)

Rey, P. F.; Coltice, N.; Flament, N. E.; Thébaud, N.

2013-12-01

Geochemical probing of ancient sediments (REE in black shales, strontium composition of carbonates, oxygen isotopes in zircons...) suggests that continents were a late Archean addition at Earth's surface. Yet, geochemical probing of ancient basalts reveals that they were extracted from a mantle depleted of its crustal elements early in the Archean. Considerations on surface geology, the early Earth hypsometry and the rheology and density structure of Archean continents can help solve this paradox. Surface geology: The surface geology of Archean cratons is characterized by thick continental flood basalts (CFBs, including greenstones) emplaced on felsic crusts dominated by Trondhjemite-Tonalite-Granodiorite (TTG) granitoids. This simple geology is peculiar because i/ most CFBs were emplaced below sea level, ii/ after their emplacement, CFBs were deformed into relatively narrow, curviplanar belts (greenstone basins) wrapping around migmatitic TTG domes, and iii/ Archean greenstone belts are richly endowed with gold and other metals deposits. Flat Earth hypothesis: From considerations on early Earth continental geotherm and density structure, Rey and Coltice (2008) propose that, because of the increased ability of the lithosphere to flow laterally, orogenic processes in the Archean produced only subdued topography (early Earth showing that, until the late Archean, most continents were flooded and Earth was largely a water world. From this, a model consistent with many of the peculiar attributes of Archean geology, can be proposed: 1/ Continents appeared at Earth's surface at an early stage during the Hadean/Archean. However, because they were i/ covered by continental flood basalts, ii/ below sea level, and iii/ deprived of modern-style mountain belts and orogenic plateaux, early felsic

Criticality analyses of regions containing uranium in the earth history

International Nuclear Information System (INIS)

Ravnik, M.

2005-01-01

Investigations of necessary conditions for a self-sustained chain reaction in the Earth inner regions hypothetically containing uranium is presented for the time interval from Earth formation to present time. It is determined that criticality was theoretically possible up to 2.5 Ga before present if uranium concentrated in pure form. In the early geological history (4 Ga before present) the self-sustained criticality could occur even if uranium was diluted up to 1:20 by the average core material or 1:60 by the average mantle material. If other metallic materials of similar density as uranium (e.g., Au, W) or similar atomic weight (e.g., Th) concentrated from the primordial mixture in equal proportion as uranium, criticality was not possible for any period in Earth history provided that the basic material contained no light nuclides (H, C). Criticality in the Earth inner regions could have established only if uranium concentrated from the basic material more effectively than elements of similar density or atomic number. (orig.)

Early diagnosis and early intervention in cerebral palsy

Directory of Open Access Journals (Sweden)

Mijna eHadders-Algra

2014-09-01

Full Text Available This paper reviews the opportunities and challenges for early diagnosis and early intervention in cerebral palsy (CP. CP describes a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to disturbances that occurred in the fetal or infant brain. Therefore the paper starts with a summary of relevant information from developmental neuroscience. Most lesions underlying CP occur in the second half of gestation, when developmental activity in the brain reaches its summit. Variations in timing of the damage not only result in different lesions, but also in different neuroplastic reactions and different associated neuropathologies. This turns CP into a heterogeneous entity. This may mean that the best early diagnostics and the best intervention methods may differ for various subgroups of children with CP. Next, the paper addresses possibilities for early diagnosis. It discusses the predictive value of neuromotor and neurological exams, neuro-imaging techniques and neurophysiological assessments. Prediction is best when complementary techniques are used in longitudinal series. Possibilities for early prediction of CP differ for infants admitted to neonatal intensive care and other infants. In the former group best prediction is achieved with the combination of neuro-imaging and the assessment of general movements, in the latter group best prediction is based on carefully documented milestones and neurological assessment. The last part reviews early intervention in infants developing CP. Most knowledge on early intervention is based on studies in high risk infants without CP. In these infants early intervention programs promote cognitive development until preschool age; motor development profits less. The few studies on early intervention in infants developing CP suggest that programs that stimulate all aspects of infant development by means of family coaching are most promising. More research is

Fascinating world of rare earth research

International Nuclear Information System (INIS)

Gschneidner, K.A. Jr.

1977-01-01

The first part of this paper concerns some of the notable events which occurred early in the author's career as a rare earther and some of the major events which took place in the two decades 1950 to 1970. The notable changes and advances in the rare earth research world since the 1971 Durham Conference are described in the second and largest part of the paper. The final portion is concerned with actinide developments since 1971

Genomes of early onset prostate cancer

DEFF Research Database (Denmark)

Weischenfeldt, Joachim; Korbel, Jan O.

2017-01-01

Purpose of review Prostate cancer is a disease of the elderly but a clinically relevant subset occurs early in life. In the current review, we discuss recent findings and the current understanding of the molecular underpinnings associated with early-onset prostate cancer (PCa) and the evidence...... supporting age-specific differences in the cancer genomes. Recent findings Recent surveys of PCa patient cohorts have provided novel age-dependent links between germline and somatic aberrations which points to differences in the molecular cause and treatment options. Summary Identifying the earliest...... receptor pathway....

31 CFR 26.3 - Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental...

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Availability of Environmental Impact Assessment Summaries (EIA Summaries) and Environmental Impact Assessments (EIAs). 26.3 Section 26.3 Money and... DEVELOPMENT BANDS (MDBs) § 26.3 Availability of Environmental Impact Assessment Summaries (EIA Summaries) and...

Incorporating Geoethics in Introductory Earth System Science Courses

Science.gov (United States)

Schmitt, J.

2014-12-01

The integrative nature of Earth System Science courses provides extensive opportunities to introduce students to geoethical inquiry focused on globally significant societal issues. Geoscience education has traditionally lagged in its efforts to increase student awareness of the significance of geologic knowledge to understanding and responsibly confronting causes and possible solutions for emergent, newly emerging, and future problems of anthropogenic cause and consequence. Developing an understanding of the human impact on the earth system requires early (lower division) and for geoscience majors, repeated (upper division) curricular emphasis on the interactions of the lithosphere, hydrosphere, atmosphere, biosphere, and pedosphere across space and through time. Capturing the interest of university students in globally relevant earth system issues and their ethical dimensions while first learning about the earth system is an important initial step in bringing geoethical deliberation and awareness to the next generation of geoscientists. Development of a new introductory Earth System Science course replacing a traditional introductory Physical Geology course at Montana State University has involved abandonment of concept-based content organization in favor of a place-based approach incorporating examination of the complex interactions of earth system components and emergent issues and dilemmas deriving from the unique component interactions that characterize each locale. Thirteen different place-based week-long modules (using web- and classroom-based instruction) were developed to ensure cumulative broad coverage across the earth geographically and earth system components conceptually. Each place-based instructional module contains content of societal relevance requiring synthesis, critical evaluation, and reflection by students. Examples include making linkages between deforestation driven by economics and increased seismicity in Haiti, agriculture and development

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Articles written in Journal of Earth System Science. Volume 119 Issue 2 April 2010 pp 137-145. Effect of co-operative fuzzy .... The efficacy of support vector machines (SVM) in robust determination of earthquake early warning magnitudes in central Japan · Ramakrushna Reddy Rajesh R Nair · More Details Abstract Fulltext ...

An Agro-Climatological Early Warning Tool Based on the Google Earth Engine to Support Regional Food Security Analysis

Science.gov (United States)

Landsfeld, M. F.; Daudert, B.; Friedrichs, M.; Morton, C.; Hegewisch, K.; Husak, G. J.; Funk, C. C.; Peterson, P.; Huntington, J. L.; Abatzoglou, J. T.; Verdin, J. P.; Williams, E. L.

2015-12-01

The Famine Early Warning Systems Network (FEWS NET) focuses on food insecurity in developing nations and provides objective, evidence based analysis to help government decision-makers and relief agencies plan for and respond to humanitarian emergencies. The Google Earth Engine (GEE) is a platform provided by Google Inc. to support scientific research and analysis of environmental data in their cloud environment. The intent is to allow scientists and independent researchers to mine massive collections of environmental data and leverage Google's vast computational resources to detect changes and monitor the Earth's surface and climate. GEE hosts an enormous amount of satellite imagery and climate archives, one of which is the Climate Hazards Group Infrared Precipitation with Stations dataset (CHIRPS). The CHIRPS dataset is land based, quasi-global (latitude 50N-50S), 0.05 degree resolution, and has a relatively long term period of record (1981-present). CHIRPS is on a continuous monthly feed into the GEE as new data fields are generated each month. This precipitation dataset is a key input for FEWS NET monitoring and forecasting efforts. FEWS NET intends to leverage the GEE in order to provide analysts and scientists with flexible, interactive tools to aid in their monitoring and research efforts. These scientists often work in bandwidth limited regions, so lightweight Internet tools and services that bypass the need for downloading massive datasets to analyze them, are preferred for their work. The GEE provides just this type of service. We present a tool designed specifically for FEWS NET scientists to be utilized interactively for investigating and monitoring for agro-climatological issues. We are able to utilize the enormous GEE computing power to generate on-the-fly statistics to calculate precipitation anomalies, z-scores, percentiles and band ratios, and allow the user to interactively select custom areas for statistical time series comparisons and predictions.

SCOSTEP: Understanding the Climate and Weather of the Sun-Earth System

Science.gov (United States)

Gopalswamy, Natchimuthuk

2011-01-01

The international solar-terrestrial physics community had recognized the importance of space weather more than a decade ago, which resulted in a number of international collaborative activities such as the Climate and Weather of the Sun Earth System (CAWSES) by the Scientific Committee on Solar Terrestrial Physics (SCOSTEP). The CAWSES program is the current major scientific program of SCOSTEP that will continue until the end of the year 2013. The CAWSES program has brought scientists from all over the world together to tackle the scientific issues behind the Sun-Earth connected system and explore ways of helping the human society. In addition to the vast array of space instruments, ground based instruments have been deployed, which not only filled voids in data coverage, but also inducted young scientists from developing countries into the scientific community. This paper presents a summary of CAWSES and other SCOSTEP activities that promote space weather science via complementary approaches in international scientific collaborations, capacity building, and public outreach.

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 109; Issue 3. Volume 109, Issue 3. September 2000, pages 315-391. pp 315-328. Ocean circulation in the tropical Indo-Pacific during early Pliocene (5.6 - 4.2 Ma): Paleobiogeographic and isotopic evidence · M S Srinivasan D K Sinha · More Details Abstract ...

An Earth-sized planet with an Earth-like density.

Science.gov (United States)

Pepe, Francesco; Cameron, Andrew Collier; Latham, David W; Molinari, Emilio; Udry, Stéphane; Bonomo, Aldo S; Buchhave, Lars A; Charbonneau, David; Cosentino, Rosario; Dressing, Courtney D; Dumusque, Xavier; Figueira, Pedro; Fiorenzano, Aldo F M; Gettel, Sara; Harutyunyan, Avet; Haywood, Raphaëlle D; Horne, Keith; Lopez-Morales, Mercedes; Lovis, Christophe; Malavolta, Luca; Mayor, Michel; Micela, Giusi; Motalebi, Fatemeh; Nascimbeni, Valerio; Phillips, David; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Szentgyorgyi, Andrew; Watson, Christopher A

2013-11-21

Recent analyses of data from the NASA Kepler spacecraft have established that planets with radii within 25 per cent of the Earth's (R Earth symbol) are commonplace throughout the Galaxy, orbiting at least 16.5 per cent of Sun-like stars. Because these studies were sensitive to the sizes of the planets but not their masses, the question remains whether these Earth-sized planets are indeed similar to the Earth in bulk composition. The smallest planets for which masses have been accurately determined are Kepler-10b (1.42 R Earth symbol) and Kepler-36b (1.49 R Earth symbol), which are both significantly larger than the Earth. Recently, the planet Kepler-78b was discovered and found to have a radius of only 1.16 R Earth symbol. Here we report that the mass of this planet is 1.86 Earth masses. The resulting mean density of the planet is 5.57 g cm(-3), which is similar to that of the Earth and implies a composition of iron and rock.

Towards earth AntineutRino TomograpHy (EARTH)

NARCIS (Netherlands)

De Meijer, R. J.; Smit, F. D.; Brooks, F. D.; Fearick, R. W.; Wortche, H. J.; Mantovani, F.

2006-01-01

The programme Earth AntineutRino TomograpHy (EARTH) proposes to build ten underground facilities each hosting a telescope. Each telescope consists of many detector modules, to map the radiogenic heat sources deep in the interior of the Earth by utilising direction sensitive geoneutrino detection.

Solar Radiation as Driving Force In Early Evolution

Science.gov (United States)

Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

2002-01-01

Ultraviolet radiation (UVR) has provided an evolutionary challenge to life on Earth in that it is both an agent of mutation and as well as a selective force. Today surface fluxes of UVR vary diurnally, seasonally, etc. Still, the UVR flux was probably substantially higher during the early phases of evolution, suggesting that its role in evolution was even more prominent during this time. In this presentation, the creative role of UVR in evolution is discussed, specifically in connection with the role that UVR may have played in the evolution of early microbial ecosystems. The presentation will include discussions of the direct influence of UVR on such processes as photosynthesis and genetic damage, as well as the indirect influence of UVR as mediated through the production of reactive oxygen species. These biological effects of UVR will be viewed against the backdrop of the physical nature of the early Earth, surely a very different place then than now.

Extending Whole-earth Tectonics To The Terrestrial Planets

Science.gov (United States)

Baker, V. R.; Maruyama, S.; Dohm, J. M.

Based on the need to explain a great many geological and geophysical anomalies on Mars, and stimulated by the new results from the Mars Global Surveyor Mission, we propose a conceptual model of whole-EARTH (Episodic Annular Revolving Thermal Hydrologic) tectonics for the long-term evolution of terrestrial planets. The theory emphasizes (1) the importance of water in planetary evolution, and (2) the physi- cal transitions in modes of mantle convection in relation to planetary heat produc- tion. Depending on their first-order geophysical parameters and following accretion and differentiation from volatile-rich planetessimals, terrestrial planets should evolve through various stages of mantle convection, including magma ocean, plate tectonic, and stagnant lid processes. If a water ocean is able to condense from the planet's early steam atmosphere, an early regime of plate tectonics will follow the initial magma ocean. This definitely happened on earth, probably on Mars, and possibly on Venus. The Mars history led to transfer of large amounts of water to the mantle during the pe- riod of heavy bombardment. Termination of plate tectonics on Mars during the heavy bombardment period led to initiation of superplumes at Tharsis and Elysium, where long-persistent volcanism and water outbursts dominated much of later Martian his- tory. For Venus, warming of the early sun made the surface ocean unstable, eliminating its early plate-tectonic regime. Although Venus now experiences stagnant-lid convec- tion with episodic mantle overturns, the water subducted to its lower mantle during the ancient plate-tectonic regime manifests itself in the initation of volatile-rich plumes that dominate its current tectonic regime.

Earth Observatory Satellite system definition study. Report 3: Design cost trade-off studies and recommendations

Science.gov (United States)

1974-01-01

An analysis of the design and cost tradeoff aspects of the Earth Observatory Satellite (EOS) development is presented. The design/cost factors that affect a series of mission/system level concepts are discussed. The subjects considered are as follows: (1) spacecraft subsystem cost tradeoffs, (2) ground system cost tradeoffs, and (3) program cost summary. Tables of data are provided to summarize the results of the analyses. Illustrations of the various spacecraft configurations are included.

Lunar Science from and for Planet Earth

Science.gov (United States)

Pieters, M. C.; Hiesinger, H.; Head, J. W., III

2008-09-01

Our Moon Every person on Earth is familiar with the Moon. Every resident with nominal eyesight on each continent has seen this near-by planetary body with their own eyes countless times. Those fortunate enough to have binoculars or access to a telescope have explored the craters, valleys, domes, and plains across the lunar surface as changing lighting conditions highlight the mysteries of this marvellously foreign landscape. Schoolchildren learn that the daily rhythm and flow of tides along the coastlines of our oceans are due to the interaction of the Earth and the Moon. This continuous direct and personal link is but one of the many reasons lunar science is fundamental to humanity. The Earth-Moon System In the context of space exploration, our understanding of the Earth-Moon system has grown enormously. The Moon has become the cornerstone for most aspects of planetary science that relate to the terrestrial (rocky) planets. The scientific context for exploration of the Moon is presented in a recent report by a subcommittee of the Space Studies Board of the National Research Council [free from the website: http://books.nap.edu/catalog.php?record_id=11954]. Figure 1 captures the interwoven themes surrounding lunar science recognized and discussed in that report. In particular, it is now recognized that the Earth and the Moon have been intimately linked in their early history. Although they subsequently took very different evolutionary paths, the Moon provides a unique and valuable window both into processes that occurred during the first 600 Million years of solar system evolution (planetary differentiation and the heavy bombardment record) as well as the (ultimately dangerous) impact record of more recent times. This additional role of the Moon as keystone is because the Earth and the Moon share the same environment at 1 AU, but only the Moon retains a continuous record of cosmic events. An Initial Bloom of Exploration and Drought The space age celebrated its 50th

Climate Engine - Monitoring Drought with Google Earth Engine

Science.gov (United States)

Hegewisch, K.; Daudert, B.; Morton, C.; McEvoy, D.; Huntington, J. L.; Abatzoglou, J. T.

2016-12-01

Drought has adverse effects on society through reduced water availability and agricultural production and increased wildfire risk. An abundance of remotely sensed imagery and climate data are being collected in near-real time that can provide place-based monitoring and early warning of drought and related hazards. However, in an era of increasing wealth of earth observations, tools that quickly access, compute, and visualize archives, and provide answers at relevant scales to better inform decision-making are lacking. We have developed ClimateEngine.org, a web application that uses Google's Earth Engine platform to enable users to quickly compute and visualize real-time observations. A suite of drought indices allow us to monitor and track drought from local (30-meters) to regional scales and contextualize current droughts within the historical record. Climate Engine is currently being used by U.S. federal agencies and researchers to develop baseline conditions and impact assessments related to agricultural, ecological, and hydrological drought. Climate Engine is also working with the Famine Early Warning Systems Network (FEWS NET) to expedite monitoring agricultural drought over broad areas at risk of food insecurity globally.

Simplify and Accelerate Earth Science Data Preparation to Systemize Machine Learning

Science.gov (United States)

Kuo, K. S.; Rilee, M. L.; Oloso, A.

2017-12-01

Data preparation is the most laborious and time-consuming part of machine learning. The effort required is usually more than linearly proportional to the varieties of data used. From a system science viewpoint, useful machine learning in Earth Science likely involves diverse datasets. Thus, simplifying data preparation to ease the systemization of machine learning in Earth Science is of immense value. The technologies we have developed and applied to an array database, SciDB, are explicitly designed for the purpose, including the innovative SpatioTemporal Adaptive-Resolution Encoding (STARE), a remapping tool suite, and an efficient implementation of connected component labeling (CCL). STARE serves as a universal Earth data representation that homogenizes data varieties and facilitates spatiotemporal data placement as well as alignment, to maximize query performance on massively parallel, distributed computing resources for a major class of analysis. Moreover, it converts spatiotemporal set operations into fast and efficient integer interval operations, supporting in turn moving-object analysis. Integrative analysis requires more than overlapping spatiotemporal sets. For example, meaningful comparison of temperature fields obtained with different means and resolutions requires their transformation to the same grid. Therefore, remapping has been implemented to enable integrative analysis. Finally, Earth Science investigations are generally studies of phenomena, e.g. tropical cyclone, atmospheric river, and blizzard, through their associated events, like hurricanes Katrina and Sandy. Unfortunately, except for a few high-impact phenomena, comprehensive episodic records are lacking. Consequently, we have implemented an efficient CCL tracking algorithm, enabling event-based investigations within climate data records beyond mere event presence. In summary, we have implemented the core unifying capabilities on a Big Data technology to enable systematic machine learning in

The history of the UV radiation climate of the earth--theoretical and space-based observations.

Science.gov (United States)

Cockell, C S; Horneck, G

2001-04-01

In the Archean era (3.8-2.5 Ga ago) the Earth probably lacked a protective ozone column. Using data obtained in the Earth's orbit on the inactivation of Bacillus subtilis spores we quantitatively estimate the potential biological effects of such an environment. We combine this practical data with theoretical calculations to propose a history of the potential UV stress on the surface of the Earth over time. The data suggest that an effective ozone column was established at a pO2 of approximately 5 x 10(-3) present atmospheric level. The improvement in the UV environment on the early Proterozoic Earth might have been a much more rapid event than has previously been supposed, with DNA damage rates dropping by two orders of magnitude in the space of just a few tens of millions of years. We postulate that a coupling between reduced UV stress and increased pO2 production could have contributed toward a positive feedback in the production of ozone in the early Proterozoic atmosphere. This would contribute to the apparent rapidity of the oxidation event. The data provide an evolutionary perspective on present-day Antarctic ozone depletion.

Rare Earth Polyoxometalates.

Science.gov (United States)

Boskovic, Colette

2017-09-19

Longstanding and important applications make use of the chemical and physical properties of both rare earth metals and polyoxometalates of early transition metals. The catalytic, optical, and magnetic features of rare earth metal ions are well-known, as are the reversible multielectron redox and photoredox capabilities of polyoxomolybdates and polyoxotungstates. The combination of rare earth ions and polyoxometalates in discrete molecules and coordination polymers is of interest for the unique combination of chemical and physical properties that can arise. This Account surveys our efforts to synthesize and investigate compounds with rare earth ions and polyoxometalates (RE-POMs), sometimes with carboxylate-based organic coligands. Our general synthetic approach is "bottom-up", which affords well-defined nanoscale molecules, typically in crystalline form and amenable to single-crystal X-ray diffraction for structure determination. Our particular focus is on elucidation of the physical properties conferred by the different structural components with a view to ultimately being able to tune these properties chemically. For this purpose, we employ a variety of spectroscopic, magnetochemical, electrochemical, and scattering techniques in concert with theoretical modeling and computation. Studies of RE-POM single-molecule magnets (SMMs) have utilized magnetic susceptibility, inelastic neutron scattering, and ab initio calculations. These investigations have allowed characterization of the crystal field splitting of the rare earth(III) ions that is responsible for the SMM properties of slow magnetic relaxation and magnetization quantum tunneling. Such SMMs are promising for applications in quantum computing and molecular spintronics. Photophysical measurements of a family of hybrid RE-POMs with organic ligands have afforded insights into sensitization of Tb(III) and Eu(III) emission through both organic and polyoxometalate chromophores in the same molecule. Detailed

Rare earth metals, rare earth hydrides, and rare earth oxides as thin films

International Nuclear Information System (INIS)

Gasgnier, M.

1980-01-01

The review deals with pure rare earth materials such as rare earth metals, rare earth hydrides, and rare earth oxides as thin films. Several preparation techniques, control methods, and nature of possible contaminations of thin films are described. These films can now be produced in an extremely well-known state concerning chemical composition, structure and texture. Structural, electric, magnetic, and optical properties of thin films are studied and discussed in comparison with the bulk state. The greatest contamination of metallic rare earth thin films is caused by reaction with hydrogen or with water vapour. The compound with an f.c.c. structure is the dihydride LnH 2 (Ln = lanthanides). The oxygen contamination takes place after annealing at higher temperatures. Then there appears a compound with a b.c.c. structure which is the C-type sesquioxide C-Ln 2 O 3 . At room atmosphere dihydride light rare earth thin films are converted to hydroxide Ln(OH) 3 . For heavy rare earth thin films the oxinitride LnNsub(x)Osub(y) is observed. The LnO-type compound was never seen. The present review tries to set the stage anew for the investigations to be undertaken in the future especially through the new generations of electron microscopes

Biofuels: Project summaries

Energy Technology Data Exchange (ETDEWEB)

1994-07-01

The US DOE, through the Biofuels Systems Division (BSD) is addressing the issues surrounding US vulnerability to petroleum supply. The BSD goal is to develop technologies that are competitive with fossil fuels, in both cost and environmental performance, by the end of the decade. This document contains summaries of ongoing research sponsored by the DOE BSD. A summary sheet is presented for each project funded or in existence during FY 1993. Each summary sheet contains and account of project funding, objectives, accomplishments and current status, and significant publications.

Educating the Public about Deep-Earth Science

Science.gov (United States)

Cronin, V. S.

2010-12-01

The nature of Earth’s interior is an active frontier of scientific research. Much of our current understanding of sub-crustal Earth is based on knowledge acquired in the last 2-3 decades, made possible by public funding and by dense seismic arrays, satellite remote sensing, increases in computer power that enable use of enhanced numerical techniques, improved theoretical and experimental knowledge of high PT mineral physics and chemistry, and a vigorous scientific community that has been trained to take advantage of these opportunities. An essential component of science is effective communication; therefore, providing for public education about science is a responsibility of the research community. Current public understanding of Earth’s interior is meager at best. In pre-college texts and in non-technical mass media, Earth's interior is typically visualized as an onion or baseball of concentric different-colored shells along whose upper surface "crustal" plates move like packages on conveyor belts of convecting mantle. Or the crust is thought to float on a molten mantle, as in the 19th century ideas of William Lowthian Green. Misconceptions about Earth that are brought to the undergraduate classroom must be confronted frankly and replaced by current understanding based on good science. Persistent ignorance has consequences. What do we want the public to know? First, the public should understand that knowledge of Earth's interior is important, not irrelevant. The public should know that deep-Earth processes result in Earth's dynamic magnetic field. Deep-Earth processes affect how radiation from the Sun reaches Earth, consequently affecting the atmosphere, the oceans, and the viability of life on Earth. The composition and differentiated structure of Earth's interior is a result of the early accretionary history of Earth and the Earth-Moon system. The public should also know that lithospheric tectonics, with all of its consequences (dynamic topography, volcanoes

Archean komatiite volcanism controlled by the evolution of early continents.

Science.gov (United States)

Mole, David R; Fiorentini, Marco L; Thebaud, Nicolas; Cassidy, Kevin F; McCuaig, T Campbell; Kirkland, Christopher L; Romano, Sandra S; Doublier, Michael P; Belousova, Elena A; Barnes, Stephen J; Miller, John

2014-07-15

The generation and evolution of Earth's continental crust has played a fundamental role in the development of the planet. Its formation modified the composition of the mantle, contributed to the establishment of the atmosphere, and led to the creation of ecological niches important for early life. Here we show that in the Archean, the formation and stabilization of continents also controlled the location, geochemistry, and volcanology of the hottest preserved lavas on Earth: komatiites. These magmas typically represent 50-30% partial melting of the mantle and subsequently record important information on the thermal and chemical evolution of the Archean-Proterozoic Earth. As a result, it is vital to constrain and understand the processes that govern their localization and emplacement. Here, we combined Lu-Hf isotopes and U-Pb geochronology to map the four-dimensional evolution of the Yilgarn Craton, Western Australia, and reveal the progressive development of an Archean microcontinent. Our results show that in the early Earth, relatively small crustal blocks, analogous to modern microplates, progressively amalgamated to form larger continental masses, and eventually the first cratons. This cratonization process drove the hottest and most voluminous komatiite eruptions to the edge of established continental blocks. The dynamic evolution of the early continents thus directly influenced the addition of deep mantle material to the Archean crust, oceans, and atmosphere, while also providing a fundamental control on the distribution of major magmatic ore deposits.

Summaries of physical research in the geosciences

Energy Technology Data Exchange (ETDEWEB)

1980-08-01

The Department of Energy supports research in the geosciences in order to provide a sound underlay of fundamental knowledge in those areas of the earth, atmospheric, and solar/terrestrial sciences that relate to the Department of Energy's many missions. The Division of Engineering, Mathematical and Geosciences, which is a part of the Office of Basic Energy Sciences and comes under the Director of Energy Research, supports under its Geosciences program major Department of Energy laboratories, industry, universities and other governmental agencies. The summaries in this document, prepared by the investigators, describe the overall scope of the individual programs and details of the research performed during 1979-1980. The Geoscience program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology and natural resource analysis, including the various subdivisions and interdisciplinary areas. All such research is related to the Department's technological needs, either directly or indirectly.

Comet/Asteroid Protection System (CAPS): A Space-Based System Concept for Revolutionizing Earth Protection and Utilization of Near-Earth Objects

Science.gov (United States)

Mazanek, Daniel D.; Roithmayr, Carlos M.; Antol, Jeffrey; Kay-Bunnell, Linda; Werner, Martin R.; Park, Sang-Young; Kumar, Renjith R.

2002-01-01

There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS is a future spacebased system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This paper provides a summary of CAPS and discusses several key areas and technologies that are being investigated.

The neodymium stable isotope composition of the silicate Earth and chondrites

Science.gov (United States)

McCoy-West, Alex J.; Millet, Marc-Alban; Burton, Kevin W.

2017-12-01

The non-chondritic neodymium (Nd) 142Nd/144Nd ratio of the silicate Earth potentially provides a key constraint on the accretion and early evolution of the Earth. Yet, it is debated whether this offset is due to the Earth being formed from material enriched in s-process Nd isotopes or results from an early differentiation process such as the segregation of a late sulfide matte during core formation, collisional erosion or a some combination of these processes. Neodymium stable isotopes are potentially sensitive to early sulfide segregation into Earth's core, a process that cannot be resolved using their radiogenic counterparts. This study presents the first comprehensive Nd stable isotope data for chondritic meteorites and terrestrial rocks. Stable Nd measurements were made using a double spike technique coupled with thermal ionisation mass spectrometry. All three of the major classes of chondritic meteorites, carbonaceous, enstatite and ordinary chondrites have broadly similar isotopic compositions allowing calculation of a chondritic mean of δ146/144Nd = -0.025 ± 0.025‰ (±2 s.d.; n = 39). Enstatite chondrites yield the most uniform stable isotope composition (Δ146/144Nd = 26 ppm), with considerably more variability observed within ordinary (Δ146/144Nd = 72 ppm) and carbonaceous meteorites (Δ146/144Nd = 143 ppm). Terrestrial weathering, nucleosynthetic variations and parent body thermal metamorphism appear to have little measurable effect on δ146/144Nd in chondrites. The small variations observed between ordinary chondrite groups most likely reflect inherited compositional differences between parent bodies, with the larger variations observed in carbonaceous chondrites being linked to varying modal proportions of calcium-aluminium rich inclusions. The terrestrial samples analysed here include rocks ranging from basaltic to rhyolitic in composition, MORB glasses and residual mantle lithologies. All of these terrestrial rocks possess a broadly similar Nd

Capturing near-Earth asteroids around Earth

Science.gov (United States)

Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

2012-12-01

The list of detected near-Earth asteroids (NEAs) is constantly growing. NEAs are likely targets for resources to support space industrialization, as they may be the least expensive source of certain needed raw materials. The limited supply of precious metals and semiconducting elements on Earth may be supplemented or even replaced by the reserves floating in the form of asteroids around the solar system. Precious metals make up a significant fraction NEAs by mass, and even one metallic asteroid of ˜1km size and fair enrichment in platinum-group metals would contain twice the tonnage of such metals already harvested on Earth. There are ˜1000 NEAs with a diameter of greater than 1 km. Capturing these asteroids around the Earth would expand the mining industry into an entirely new dimension. Having such resources within easy reach in Earth's orbit could provide an off-world environmentally friendly remedy for impending terrestrial shortages, especially given the need for raw materials in developing nations. In this paper, we develop and implement a conceptually simple algorithm to determine trajectory characteristics necessary to move NEAs into capture orbits around the Earth. Altered trajectories of asteroids are calculated using an ephemeris model. Only asteroids of eccentricity less than 0.1 have been studied and the model is restricted to the ecliptic plane for simplicity. We constrain the time of retrieval to be 10 years or less, based on considerations of the time to return on investment. For the heliocentric phase, constant acceleration is assumed. The acceleration required for transporting these asteroids from their undisturbed orbits to the sphere of influence of the Earth is the primary output, along with the impulse or acceleration necessary to effect capture to a bound orbit once the Earth's sphere of influence is reached. The initial guess for the constant acceleration is provided by a new estimation method, similar in spirit to Edelbaum's. Based on the

Optimal Safety Earthing – Earth Electrode Sizing Using A ...

African Journals Online (AJOL)

In this paper a deterministic approach in the sizing of earth electrode using the permissible touch voltage criteria is presented. The deterministic approach is effectively applied in the sizing of the length of earth rod required for the safe earthing of residential and facility buildings. This approach ensures that the earthing ...

Earth Tidal Controls on Basal Dynamics and Hydrology

Science.gov (United States)

Kulessa, B.; Hubbard, B. P.; Brown, G. H.; Becker, J.

2001-12-01

We appraise earth tidal forcing of coupled mechanical and hydrological processes beneath warm-based ice masses, which have to date been poorly documented but represent exciting phenomena that have important implications for future studies of glacier dynamics. Regular cycles in winter and early spring electrical self-potential (SP), water pressure (PW) and electrical conductivity (EC) were recorded at the bases of several boreholes drilled through Haut Glacier d'Arolla, Switzerland. Fourier power spectra of these data reflect the presence of diurnal and semi-diurnal cycles, and comparison with the earth tidal spectrum indicates that at least four components of the latter are visible in the borehole spectra: the luni-solar diurnal, the principal lunar diurnal, the principal solar semi-diurnal, and the principal lunar semi-diurnal. This correspondence suggests that earth tides exert a strong control over water flow at the bed of the glacier, at least during winter and early spring. We envisage a mechanism that involves earth-tide induced deformation of the bedrock and the unconsolidated sediments beneath the glacier, and to a certain extent probably also the overlying ice body. Basal water pockets, including those containing our sensors, located within these media are in turn also likely to be deformed periodically. We believe that PW gradients induced by such deformation may result in transient water flow and SPs in the pockets. Since PW and EC are typically out-of-phase, injection of waters of lower EC into the pockets during times of peak water flow is likely. Several lines of evidence suggest that such injection was caused by melting of the ice wall due to frictional heating, balancing creep closure which sustained some pockets through the winter. Further, the first annually-repeated post-winter reorganization event, termed the May event, may well be triggered by tidally-induced releases of waters from storage. This implies that the May event marks the opening of

Evolution of the Earth and Origin of Life: The Role of Gas/Fluid Interactions with Rocks

Science.gov (United States)

Freund, Friedemann

2001-01-01

The work under the Cooperative Agreement will be centered on questions of the evolution of Life on the early Earth and possibly on Mars. It is still hotly debated whether the essential organic molecules were delivered to the early Earth from space (by comets, meteorites or interplanetary dust particles) or were generated in situ on Earth. Prior work that has shown that the matrix of igneous minerals is a medium in which progenitors of organic molecules assemble from H2O, C02 and N2 incorporated as minority "impurities" in minerals of igneous rocks during crystallization from H2O/CO2/N2-laden magmas. The underlying processes involve a redox. conversion whereby C, H, and N become chemically reduced, while 0 becomes oxidized to the peroxy state. During Year 02 the work will be divided into three tasks. Task 1: After carboxylic (fatty) acids and N-bearing compounds have been identified, other extractable organic molecules including lipids, oily substances and amino acids will be studied. Dedicated lipid analysis will be combined with gas chromatographic-mass spectroscopic (GCMS) analysis of organic compounds extracted from minerals and rocks. Task 2: Using infrared (IR) spectroscopy, C-H entities that are indicators for the organic progenitors in mineral matrices will be studied. A preliminary heating experiment with MgO single crystals has shown that the C-H entities can be pyrolyzed, causing the IR bands to disappear, but at room temperature the IR bands reappear in a matter of days to weeks. This work will be expanded, both by studying synthetic MgO crystals and olivine crystals from the Earth's upper mantle. The C-H bands will be compared to the published "organic" IR feature of dust in the interstellar medium (ISM) and interplanetary dust particles (IDP). Task 3: A paradox marks the evolution of early Life: Oxygen is highly toxic to primitive life, yet early organisms "learned" to detoxify reactive oxygen species, to utilize oxygen, and even produce it. Why would

Evidence for and implications of an Early Archean terrestrial impact record

International Nuclear Information System (INIS)

Lowe, D.R.; Byerly, G.R.

1988-01-01

Early Archean, 3.5 to 3.2 Ga, greenstone sequences in South Africa and Western Australia contain a well-preserved record of early terrestrial meteorite impacts. The main impact-produced deposits are layers, 10 cm to over 1 m thick, composed largely of sand-sized spherules, 0.1 to 4 mm in diameter. The beds studied to date show an assemblage of features indicating formation by the fall of debris from impact-generated ejecta clouds. Some presented data effectively rule out normal magmatic or sedimentary processes in the origin of these units and provide substantial support for an origin by large impacts on the early earth. The presence of at least four, remarkably thick, nearly pure spherule layers suggests that smaller-scale impact deposits may be even more abundant in these sequences. The existence of a well-preserved Archean terrestrial impact record suggests that a direct source of evidence is available regarding a number of important aspects of early earth history

Mapping the early Universe

Energy Technology Data Exchange (ETDEWEB)

Anon.

1991-06-15

From its unique vantage point 900 kilometres above the earth's surface, NASA's Cosmic Background Explorer (COBE) satellite has a privileged view of cosmic background radiation - the remnants of the early (radiation-dominated) Universe which followed the Big Bang some ten Gigayears ago, and possibly some subsequent history. In this way astroparticle physicists get a first peek at the quantum cosmology which moulded the infant Universe.

USERDA computer program summaries. Numbers 177--239

International Nuclear Information System (INIS)

1975-10-01

Since 1960 the Argonne Code Center has served as a U. S. Atomic Energy Commission information center for computer programs developed and used primarily for the solution of problems in nuclear physics, reactor design, reactor engineering and operation. The Center, through a network of registered installations, collects, validates, maintains, and distributes a library of these computer programs and publishes a compilation of abstracts describing them. In 1972 the scope of the Center's activities was officially expanded to include computer programs developed in all of the U. S. Atomic Energy Commission program areas and the compilation and publication of this report. The Computer Program Summary report contains summaries of computer programs at the specification stage, under development, being checked out, in use, or available at ERDA offices, laboratories, and contractor installations. Programs are divided into the following categories: cross section and resonance integral calculations; spectrum calculations, generation of group constants, lattice and cell problems; static design studies; depletion, fuel management, cost analysis, and reactor economics; space-independent kinetics; space--time kinetics, coupled neutronics--hydrodynamics--thermodynamics and excursion simulations; radiological safety, hazard and accident analysis; heat transfer and fluid flow; deformation and stress distribution computations, structural analysis and engineering design studies; gamma heating and shield design programs; reactor systems analysis; data preparation; data management; subsidiary calculations; experimental data processing; general mathematical and computing system routines; materials; environmental and earth sciences; space sciences; electronics and engineering equipment; chemistry; particle accelerators and high-voltage machines; physics; controlled thermonuclear research; biology and medicine; and data

Replicating the Ice-Volume Signal of the Early Pleistocene with a Complex Earth System Model

Science.gov (United States)

Tabor, C. R.; Poulsen, C. J.; Pollard, D.

2013-12-01

Milankovitch theory proposes high-latitude summer insolation intensity paces the ice ages by controlling perennial snow cover amounts (Milankovitch, 1941). According to theory, the ~21 kyr cycle of precession should dominate the ice-volume records since it has the greatest influence on high-latitude summer insolation. Modeling experiments frequently support Milankovitch theory by attributing the majority of Northern Hemisphere high-latitude summer snowmelt to changes in the cycle of precession (e.g. Jackson and Broccoli, 2003). However, ice-volume proxy records, especially those of the Early Pleistocene (2.6-0.8 Ma), display variability with a period of ~41 kyr (Raymo and Lisiecki, 2005), indicative of insolation forcing from obliquity, which has a much smaller influence on summer insolation intensity than precession. Several hypotheses attempt to explain the discrepancies between Milkankovitch theory and the proxy records by invoking phenomena such as insolation gradients (Raymo and Nisancioglu, 2003), hemispheric offset (Raymo et al., 2006; Lee and Poulsen, 2009), and integrated summer energy (Huybers, 2006); however, all of these hypotheses contain caveats (Ruddiman, 2006) and have yet to be supported by modeling studies that use a complex GCM. To explore potential solutions to this '41 kyr problem,' we use an Earth system model composed of the GENESIS GCM and Land Surface model, the BIOME4 vegetation model, and the Pennsylvania State ice-sheet model. Using an asynchronous coupling technique, we run four idealized transient combinations of obliquity and precession, representing the orbital extremes of the Pleistocene (Berger and Loutre, 1991). Each experiment is run through several complete orbital cycles with a dynamic ice domain spanning North America and Greenland, and fixed preindustrial greenhouse-gas concentrations. For all orbital configurations, model results produce greater ice-volume spectral power at the frequency of obliquity despite significantly

Policy for Robust Space-based Earth Science, Technology and Applications

Science.gov (United States)

Brown, Molly Elizabeth; Escobar, Vanessa Marie; Aschbacher, Josef; Milagro-Pérez, Maria Pilar; Doorn, Bradley; Macauley, Molly K.; Friedl, Lawrence

2013-01-01

Satellite remote sensing technology has contributed to the transformation of multiple earth science domains, putting space observations at the forefront of innovation in earth science. With new satellite missions being launched every year, new types of earth science data are being incorporated into science models and decision-making systems in a broad array of organizations. Policy guidance can influence the degree to which user needs influence mission design and when, and ensure that satellite missions serve both the scientific and user communities without becoming unfocused and overly expensive. By considering the needs of the user community early on in the mission-design process, agencies can ensure that satellites meet the needs of multiple constituencies. This paper describes the mission development process in NASA and ESA and compares and contrasts the successes and challenges faced by these agencies as they try to balance science and applications within their missions.

Modeling Earth Albedo for Satellites in Earth Orbit

DEFF Research Database (Denmark)

Bhanderi, Dan; Bak, Thomas

2005-01-01

Many satellite are influences by the Earthøs albedo, though very few model schemes exist.in order to predict this phenomenon. Earth albedo is often treated as noise, or ignored completely. When applying solar cells in the attitude hardware, Earth albedo can cause the attitude estimate to deviate...... with as much as 20 deg. Digital Sun sensors with Earth albedo correction in hardware exist, but are expensive. In addition, albedo estimates are necessary in thermal calculations and power budgets. We present a modeling scheme base4d on Eartht reflectance, measured by NASA's Total Ozone Mapping Spectrometer......, in which the Earth Probe Satellite has recorded reflectivity data daily since mid 1996. The mean of these data can be used to calculate the Earth albedo given the positions of the satellite and the Sun. Our results show that the albedo varies highly with the solar angle to the satellite's field of view...

Radiogenic isotopes: the case for crustal recycling on a near-steady-state no-continental-growth Earth

International Nuclear Information System (INIS)

Armstrong, R.L.

1981-01-01

The proposition that continental crust is recycled into the mantle and that the Earth is in a near-steady state with essentially constant volumes of oceans and crust through geological time is defended. Constancy of continental freeboard and uniformity of thickness of stable continental crust with age are the only two quantitative measures of crustal volume through time and these imply negligible crustal growth since 2.9 Ga B.P. Planetary analogies, Pb isotopes, atmospheric evolution, and palaeomagnetism also argue for early terrestrial differentiation. Rates of crustal growth and recycling are sufficient to reach a near-steady state over the first 1 Ga of Earth history, before widespread cratonization. Pb, Sr and Nd isotopic compositions of igneous rocks from the mantle are explainable in terms of a near-steady-state model. The recycling process can be observed on the Earth today. The observed escape of primordial 3 He from the mantle is not evidence for continuing continental differentiation or against early differentiation of the Earth. Even if nearly complete equilibrium chemical differentiation occurred at 4.6 Ga B.P., some 3 He would remain dissolved in the interior and would escape as recycling continued. (U.K.)

Early haemorrhage control and management of trauma-induced coagulopathy

DEFF Research Database (Denmark)

Stensballe, Jakob; Henriksen, Hanne H; Johansson, Pär I

2017-01-01

of trauma resuscitation using a ratio-driven strategy aiming at 1:1:1 of red blood cells, plasma and platelets while applying goal-directed therapy early and repeatedly to control trauma-induced coagulopathy. SUMMARY: Trauma resuscitation should focus on early goal-directed therapy with use of viscoelastic...... haemostatic assays while initially applying a ratio 1:1:1 driven transfusion therapy (with red blood cells, plasma and platelets) in order to sustain normal haemostasis and control further bleeding....

The geological record of life 3500 Ma ago: Coping with the rigors of a young earth during late accretion

Science.gov (United States)

Lowe, Donald R.

1989-01-01

Thin cherty sedimentary layers within the volcanic portions of the 3,500 to 3,300 Ma-old Onverwacht and Fig Tree Groups, Barberton Greenstone belt, South Africa, and Warrawoona Group, eastern Pilbara Block, Western Australia, contain an abundant record of early Archean life. Five principal types of organic and probably biogenic remains and or structures can be identifed: stromatolites, stromatolite detritus, carbonaceous laminite or flat stromalite, carbonaceous detrital particles, and microfossils. Early Archean stromatolites were reported from both the Barberton and eastern Pilbara greenstone belts. Systematic studies are lacking, but two main morphological types of stromatolites appear to be represented by these occurrences. Morphology of the stromalites is described. Preserved early Archean stromatolites and carbonaceous matter appear to reflect communities of photosynthetic cyanobacteria inhabiting shallow, probably marine environments developed over the surfaces of low-relief, rapidly subsiding, simatic volcanic platforms. The overall environmental and tectonic conditions were those that probably prevailed at Earth's surface since the simatic crust and oceans formed sometime before 3,800 Ma. Recent studies also suggest that these early Archean sequences contain layers of debris formed by large-body impacts on early Earth. If so, then these early bacterial communities had developed strategies for coping with the disruptive effects of possibly globe-encircling high-temperature impact vapor clouds, dust blankets, and impact-generated tsunamis. It is probable that these early Archean biogenic materials represent organic communities that evolved long before the beginning of the preserved geological record and were well adapted to the rigors of life on a young, volcanically active Earth during late bombardment. These conditions may have had parallels on Mars during its early evolution.

Earth as an extrasolar planet: Earth model validation using EPOXI earth observations.

Science.gov (United States)

Robinson, Tyler D; Meadows, Victoria S; Crisp, David; Deming, Drake; A'hearn, Michael F; Charbonneau, David; Livengood, Timothy A; Seager, Sara; Barry, Richard K; Hearty, Thomas; Hewagama, Tilak; Lisse, Carey M; McFadden, Lucy A; Wellnitz, Dennis D

2011-06-01

The EPOXI Discovery Mission of Opportunity reused the Deep Impact flyby spacecraft to obtain spatially and temporally resolved visible photometric and moderate resolution near-infrared (NIR) spectroscopic observations of Earth. These remote observations provide a rigorous validation of whole-disk Earth model simulations used to better understand remotely detectable extrasolar planet characteristics. We have used these data to upgrade, correct, and validate the NASA Astrobiology Institute's Virtual Planetary Laboratory three-dimensional line-by-line, multiple-scattering spectral Earth model. This comprehensive model now includes specular reflectance from the ocean and explicitly includes atmospheric effects such as Rayleigh scattering, gas absorption, and temperature structure. We have used this model to generate spatially and temporally resolved synthetic spectra and images of Earth for the dates of EPOXI observation. Model parameters were varied to yield an optimum fit to the data. We found that a minimum spatial resolution of ∼100 pixels on the visible disk, and four categories of water clouds, which were defined by using observed cloud positions and optical thicknesses, were needed to yield acceptable fits. The validated model provides a simultaneous fit to Earth's lightcurve, absolute brightness, and spectral data, with a root-mean-square (RMS) error of typically less than 3% for the multiwavelength lightcurves and residuals of ∼10% for the absolute brightness throughout the visible and NIR spectral range. We have extended our validation into the mid-infrared by comparing the model to high spectral resolution observations of Earth from the Atmospheric Infrared Sounder, obtaining a fit with residuals of ∼7% and brightness temperature errors of less than 1 K in the atmospheric window. For the purpose of understanding the observable characteristics of the distant Earth at arbitrary viewing geometry and observing cadence, our validated forward model can be

Rare Earth Garnet Selective Emitter

Science.gov (United States)

Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

1994-01-01

Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approx. = 0.75, sup 4)|(sub 15/2) - (sup 4)|(sub 13/2),for Er-YAG and epsilon(sub lambda) approx. = 0.65, (sup 5)|(sub 7) - (sup 5)|(sub 8) for Ho-YAG) at 1500 K. In addition, low out-of-band spectral emittance, epsilon(sub lambda) less than 0.2, suggest these materials would be excellent candidates for high efficiency selective emitters in thermophotovoltaic (TPV) systems operating at moderate temperatures (1200-1500 K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. Selective emitters in the near IR are of special interest for thermophotovoltaic (TPV) energy conversion. The most promising solid selective emitters for use in a TPV system are rare earth oxides. Early spectral emittance work on rare earth oxides showed strong emission bands in the infrared (0.9 - 3 microns). However, the emittance outside the emission band was also significant and the efficiency of these emitters was low. Recent improvements in efficiency have been made with emitters fabricated from fine (5 - 10 microns) rare earth oxide fibers similar to the Welsbach mantle used in gas lanterns. However, the rare earth garnet emitters are more rugged than the mantle type emitters. A thin film selective emitter on a low emissivity substrate such as gold, platinum etc., is rugged and easily adapted to a wide variety of thermal sources. The garnet structure and its many subgroups have been successfully used as hosts for rare earth ions, introduced as substitutional

Cubic zirconia in >2370 °C impact melt records Earth's hottest crust

Science.gov (United States)

Timms, Nicholas E.; Erickson, Timmons M.; Zanetti, Michael R.; Pearce, Mark A.; Cayron, Cyril; Cavosie, Aaron J.; Reddy, Steven M.; Wittmann, Axel; Carpenter, Paul K.

2017-11-01

Bolide impacts influence primordial evolution of planetary bodies because they can cause instantaneous melting and vaporization of both crust and impactors. Temperatures reached by impact-generated silicate melts are unknown because meteorite impacts are ephemeral, and established mineral and rock thermometers have limited temperature ranges. Consequently, impact melt temperatures in global bombardment models of the early Earth and Moon are poorly constrained, and may not accurately predict the survival, stabilization, geochemical evolution and cooling of early crustal materials. Here we show geological evidence for the transformation of zircon to cubic zirconia plus silica in impact melt from the 28 km diameter Mistastin Lake crater, Canada, which requires super-heating in excess of 2370 °C. This new temperature determination is the highest recorded from any crustal rock. Our phase heritage approach extends the thermometry range for impact melts by several hundred degrees, more closely bridging the gap between nature and theory. Profusion of >2370 °C superheated impact melt during high intensity bombardment of Hadean Earth likely facilitated consumption of early-formed crustal rocks and minerals, widespread volatilization of various species, including hydrates, and formation of dry, rigid, refractory crust.

Advancing land surface model development with satellite-based Earth observations

Science.gov (United States)

Orth, Rene; Dutra, Emanuel; Trigo, Isabel F.; Balsamo, Gianpaolo

2017-04-01

The land surface forms an essential part of the climate system. It interacts with the atmosphere through the exchange of water and energy and hence influences weather and climate, as well as their predictability. Correspondingly, the land surface model (LSM) is an essential part of any weather forecasting system. LSMs rely on partly poorly constrained parameters, due to sparse land surface observations. With the use of newly available land surface temperature observations, we show in this study that novel satellite-derived datasets help to improve LSM configuration, and hence can contribute to improved weather predictability. We use the Hydrology Tiled ECMWF Scheme of Surface Exchanges over Land (HTESSEL) and validate it comprehensively against an array of Earth observation reference datasets, including the new land surface temperature product. This reveals satisfactory model performance in terms of hydrology, but poor performance in terms of land surface temperature. This is due to inconsistencies of process representations in the model as identified from an analysis of perturbed parameter simulations. We show that HTESSEL can be more robustly calibrated with multiple instead of single reference datasets as this mitigates the impact of the structural inconsistencies. Finally, performing coupled global weather forecasts we find that a more robust calibration of HTESSEL also contributes to improved weather forecast skills. In summary, new satellite-based Earth observations are shown to enhance the multi-dataset calibration of LSMs, thereby improving the representation of insufficiently captured processes, advancing weather predictability and understanding of climate system feedbacks. Orth, R., E. Dutra, I. F. Trigo, and G. Balsamo (2016): Advancing land surface model development with satellite-based Earth observations. Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-628

Digital Earth - A sustainable Earth

Science.gov (United States)

Mahavir

2014-02-01

All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth.

Summary big data

CERN Document Server

2014-01-01

This work offers a summary of Cukier the book: "Big Data: A Revolution That Will Transform How we Live, Work, and Think" by Viktor Mayer-Schonberg and Kenneth. Summary of the ideas in Viktor Mayer-Schonberg's and Kenneth Cukier's book: " Big Data " explains that big data is where we use huge quantities of data to make better predictions based on the fact we identify patters in the data rather than trying to understand the underlying causes in more detail. This summary highlights that big data will be a source of new economic value and innovation in the future. Moreover, it shows that it will

Messengers of the universe: Session IV Summary

International Nuclear Information System (INIS)

Bernardini, Elisa; Serpico, Pasquale Dario

2013-01-01

Being stable, light and neutral weakly interacting particles, neutrinos are ideal messengers of the deep universe and a channel of choice in particular to explore the very high energy Galactic and Extragalactic sky, playing a synergic role most notably with gamma-ray observations. Neutrino astronomy—long after the SN1987A detection in the MeV range—is mature enough for decisive tests of astrophysical paradigms. Its current status constitutes one of the two big pillars of the “Messengers of the universe” session of the Neutrino Oscillation Workshop 2012. Neutrinos may also play a role in some cosmological contexts, such as the early universe and the dark matter problem. We review both aspects in this session summary report

Summary information report

International Nuclear Information System (INIS)

1982-07-01

The Summary Information Report (SIR) provides summary data concerning NRC and its licensees for general use by the Chairman, other Commissioners and Commission staff offices, the Executive Director for Operations, and the Office Directors. SIR is published quarterly by the Management Information Branch (49-27834) of the Office of Resource Management

Use of the Earth Observing One (EO-1) Satellite for the Namibia SensorWeb Flood Early Warning Pilot

Science.gov (United States)

Mandl, Daniel; Frye, Stuart; Cappelaere, Pat; Handy, Matthew; Policelli, Fritz; Katjizeu, McCloud; Van Langenhove, Guido; Aube, Guy; Saulnier, Jean-Francois; Sohlberg, Rob;

Daily monitoring of the land surface of the Earth

Science.gov (United States)

Mascaro, J.

2016-12-01

Planet is an integrated aerospace and data analytics company that operates the largest fleet of Earth-imaging satellites. With more than 140 cube-sats successfully launched to date, Planet is now collecting approximately 10 million square kilometers of imagery per day (3-5m per pixel, in red, green, blue and near infrared spectral bands). By early 2017, Planet's constellation will image the entire land surface of the Earth on a daily basis. Due to investments in cloud storage and computing, approximately 75% of imagery collected is available to Planet's partners within 24 hours of capture through an Application Program Interface. This unique dataset has enormous applications for monitoring the status of Earth's natural ecosystems, as well as human settlements and agricultural welfare. Through our Ambassadors Program, Planet has made data available for researchers in areas as disparate as human rights monitoring in refugee camps, to assessments of the impact of hydroelectric installations, to tracking illegal gold mining in Amazon forests, to assessing the status of the cryosphere. Here, we share early results from Planet's research partner network, including enhanced spatial and temporal resolution of NDVI data for agricultural health in Saudi Arabia, computation of rates of illegal deforestation in Southern Peru, estimates of tropical forest carbon stocks based on data integration with active sensors, and estimates of glacial flow rates. We synthesize the potentially enormous research and scientific value of Planet's persistent monitoring capability, and discuss methods by which the data will be disseminated into the scientific community.

Geology and rare earth (RE) metals in air Gegas area, South Bangka

International Nuclear Information System (INIS)

Bambang Soetopo

2013-01-01

Rare Earth (RE) is a valuable commodity both for industry and for the Nuclear Power Plant (NPP). In RE chemical bonds present in the phosphate (P) are the mineral monazite, xenotime, zircon minerals associated with cassiterite, magnetite, ilmenite, rutile, anatase, apatite, quartz and feldspar sand deposits are found in alluvial river or beach placer. RE deposits in monazite, zircon, xenotime in the Air Gegas of South Bangka area is an alluvial river that has the ease of exploration and mining. Geologically, monazite, xenotime and zircon minerals are from Klabat Granite aged Jurassic. The used method are the observation of geology, radioactivity measurement, sampling, laboratory analysis (microscopic and XRF). Results showed that the geology of the area Air Gegas of Tanjung Genting Formation consists of sandstone, clay (Early Triassic), Klabat Granite (Late Jurassic-Early Triassic) and Alluvial sediments (Quaternary). Alluvial monazite containing 0.071 to 3.574%, zircon from 0.172 to 10.376%, xenotime from 0.15 to 3.023% of the weight of MB from 10.73 to 168.072 grams. The presence of rare earth (RE) metals is derived from the mineral monazite, xenotime, zircon that was derived from granitic rocks of Klabat. Rare earth (RE) distributed in the eastern part of the study area which occupies the valley of the river. (author)

Low-energy near Earth asteroid capture using Earth flybys and aerobraking

Science.gov (United States)

Tan, Minghu; McInnes, Colin; Ceriotti, Matteo

2018-04-01

Since the Sun-Earth libration points L1 and L2 are regarded as ideal locations for space science missions and candidate gateways for future crewed interplanetary missions, capturing near-Earth asteroids (NEAs) around the Sun-Earth L1/L2 points has generated significant interest. Therefore, this paper proposes the concept of coupling together a flyby of the Earth and then capturing small NEAs onto Sun-Earth L1/L2 periodic orbits. In this capture strategy, the Sun-Earth circular restricted three-body problem (CRTBP) is used to calculate target Lypaunov orbits and their invariant manifolds. A periapsis map is then employed to determine the required perigee of the Earth flyby. Moreover, depending on the perigee distance of the flyby, Earth flybys with and without aerobraking are investigated to design a transfer trajectory capturing a small NEA from its initial orbit to the stable manifolds associated with Sun-Earth L1/L2 periodic orbits. Finally, a global optimization is carried out, based on a detailed design procedure for NEA capture using an Earth flyby. Results show that the NEA capture strategies using an Earth flyby with and without aerobraking both have the potential to be of lower cost in terms of energy requirements than a direct NEA capture strategy without the Earth flyby. Moreover, NEA capture with an Earth flyby also has the potential for a shorter flight time compared to the NEA capture strategy without the Earth flyby.

40 CFR 1502.12 - Summary.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Summary. 1502.12 Section 1502.12 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY ENVIRONMENTAL IMPACT STATEMENT § 1502.12 Summary. Each environmental impact statement shall contain a summary which adequately and accurately summarizes...

Mapping the early Universe

International Nuclear Information System (INIS)

Anon.

1991-01-01

From its unique vantage point 900 kilometres above the earth's surface, NASA's Cosmic Background Explorer (COBE) satellite has a privileged view of cosmic background radiation - the remnants of the early (radiation-dominated) Universe which followed the Big Bang some ten Gigayears ago, and possibly some subsequent history. In this way astroparticle physicists get a first peek at the quantum cosmology which moulded the infant Universe

Earth-satellite propagation above GHz: Papers from the 1972 spring URSI session on experiments utilizing the ATS-5 satellite

Science.gov (United States)

Ippolito, L. J. (Compiler)

1972-01-01

Papers are reported from the Special Session on Earth-Satellite Propagation Above 10 GHz, presented at The 1972 Spring Meeting of the United States National Committee, International Union of Radio Science, April 1972, Washington, D. C. This session was devoted to propagation measurements associated with the Applications Technology Satellite (ATS-5), which provided the first operational earth-space links at frequencies above 15 GHz. A comprehensive summary is presented of the major results of the ATS-5 experiment measurements and related radiometric, radar and meteorological studies. The papers are organized around seven selected areas of interest, with the results of the various investigators combined into a single paper presented by a principal author for that area. A comprehensive report is provided on the results of the ATS-5 satellite to earth transmissions. A complete list of published reports and presentations related to the ATS-5 Millimeter Wave Experiment is included.

Definition of technology development missions for early space station, orbit transfer vehicle servicing. Volume 1: Executive summary

Science.gov (United States)

1983-01-01

Orbital Transfer Vehicle (OTV) servicing study scope, propellant transfer, storage and reliquefaction technology development missions (TDM), docking and berthing TDM, maintenance TDM, OTV/payload integration TDM, combined TDMS design, summary space station accomodations, programmatic analysis, and TDM equipment operational usage are discussed.

The Impact Imperative: A Space Infrastructure Enabling a Multi-Tiered Earth Defense

Science.gov (United States)

Campbell, Jonathan W.; Phipps, Claude; Smalley, Larry; Reilly, James; Boccio, Dona

2003-01-01

Impacting at hypervelocity, an asteroid struck the Earth approximately 65 million years ago in the Yucatan Peninsula a m . This triggered the extinction of almost 70% of the species of life on Earth including the dinosaurs. Other impacts prior to this one have caused even greater extinctions. Preventing collisions with the Earth by hypervelocity asteroids, meteoroids, and comets is the most important immediate space challenge facing human civilization. This is the Impact Imperative. We now believe that while there are about 2000 earth orbit crossing rocks greater than 1 kilometer in diameter, there may be as many as 200,000 or more objects in the 100 m size range. Can anything be done about this fundamental existence question facing our civilization? The answer is a resounding yes! By using an intelligent combination of Earth and space based sensors coupled with an infrastructure of high-energy laser stations and other secondary mitigation options, we can deflect inbound asteroids, meteoroids, and comets and prevent them &om striking the Earth. This can be accomplished by irradiating the surface of an inbound rock with sufficiently intense pulses so that ablation occurs. This ablation acts as a small rocket incrementally changing the shape of the rock's orbit around the Sun. One-kilometer size rocks can be moved sufficiently in about a month while smaller rocks may be moved in a shorter time span. We recommend that space objectives be immediately reprioritized to start us moving quickly towards an infrastructure that will support a multiple option defense capability. Planning and development for a lunar laser facility should be initiated immediately in parallel with other options. All mitigation options are greatly enhanced by robust early warning, detection, and tracking resources to find objects sufficiently prior to Earth orbit passage in time to allow significant intervention. Infrastructure options should include ground, LEO, GEO, Lunar, and libration point

The origin of the moon and the early history of the earth - A chemical model. Part 1: The moon

International Nuclear Information System (INIS)

O'Neill, H. St.C.

1991-01-01

The chemical implications of a giant impact model for the origin of the moon are examined, both for the moon and for the earth. The Impactor is taken to be an approximately Mars-sized body. It is argued that the likeliest bulk chemical composition of the moon is quite similar to that of the earth's mantle, and that this composition may be explained in detail if about 80% of the moon came from the primitive earth's mantle after segregation of the earth's core. The other 20% of the moon is modelled as coming from (a) the Impactor, which is constrained to be an oxidized, probably undifferentiated body of roughly CI chondritic composition (on a volatile free basis) and (b) a late stage veneer, with a composition and oxidation state similar to that of the H-group ordinary chondrites. This latter component is the source of all the volatile elements in the moon, which failed to condense from the earth-and Impactor-derived materials; this component constitutes about 4% of the moon. It is argued that Mo may behave as a volatile element under the relatively oxidising conditions necessary for the condensation of the proto-moon. The model accounts satisfactorily for most of the siderophile elements, including Fe, Ni, Co, W, P, and Cu. The relatively well-constrained lunar abundances of V, Cr, and Mn are also accounted for; their depletion in the moon is inherited from the earth's mantle

An Operationally Simple Method for Separating the Rare-Earth Elements Neodymium and Dysprosium.

Science.gov (United States)

Bogart, Justin A; Lippincott, Connor A; Carroll, Patrick J; Schelter, Eric J

2015-07-06

Rare-earth metals are critical components of electronic materials and permanent magnets. Recycling of consumer materials is a promising new source of rare earths. To incentivize recycling there is a clear need for simple methods for targeted separations of mixtures of rare-earth metal salts. Metal complexes of a tripodal nitroxide ligand [{(2-(t) BuNO)C6 H4 CH2 }3 N](3-) (TriNOx(3-) ), feature a size-sensitive aperture formed of its three η(2) -(N,O) ligand arms. Exposure of metal cations in the aperture induces a self-associative equilibrium comprising [M(TriNOx)thf]/ [M(TriNOx)]2 (M=rare-earth metal). Differences in the equilibrium constants (Keq ) for early and late metals enables simple Nd/Dy separations through leaching with a separation ratio SNd/Dy =359. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

7 CFR 3402.12 - Project summary.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Project summary. 3402.12 Section 3402.12 Agriculture... FELLOWSHIP GRANTS PROGRAM Preparation of an Application § 3402.12 Project summary. Using the Project Summary.... The summary should not include any reference to the specific number of fellowships requested. The...

Astrobiology and the Chemistry of the Early Solar System

Science.gov (United States)

Cook, Jamie Elsila

2011-01-01

The field of astrochemistry investigates the origin of the chemicals necessary for the formation of life. Astrochemists use remote observations, laboratory simulations, and analysis of extraterrestrial samples to understand the inventory of pre biotic chemicals present on the early Earth. Among the problems investigated by astrochemists is the origin of homo chirality in terrestrial life. Analysis of meteorites shows that they may have delivered an excess of L-amino acids to the Earth's surface, perhaps leading to homochirality.

The Impact of a Summer Institute on Inservice Early Childhood Teachers' Knowledge of Earth and Space Science Concepts

Science.gov (United States)

Sackes, Mesut; Trundle, Kathy Cabe; Krissek, Lawrence A.

2011-01-01

This study investigated inservice PreK to Grade two teachers' knowledge of some earth and space science concepts before and after a short-term teacher institute. A one-group pre-test-post-test design was used in the current study. Earth science concepts targeted during the professional development included properties of rocks and soils, and the…

Rare earths

Energy Technology Data Exchange (ETDEWEB)

Cranstone, D A

1979-01-01

Rare earth elements are commonly extracted from the minerals monazite, bastnaesite, and xenotine. New uses for these elements are constantly developing; they have found applications in glass polishing, television tube phosphors, high-strength low-alloy steels, magnets, catalysts, refractory ceramics, and hydrogen sponge alloys. In Canada, rare earths have been produced as byproducts of the uranium mining industry, but there was no production of rare earths in 1978 or 1979. The world sources of and markets for the rare earth elements are discussed.

49 CFR 194.113 - Information summary.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Information summary. 194.113 Section 194.113... Response Plans § 194.113 Information summary. (a) The information summary for the core plan, required by... state(s). (b) The information summary for the response zone appendix, required in § 194.107, must...

Plant exploitation during the early Natufian in north-eastern Jordan: preliminary results from Shubayqa 1

DEFF Research Database (Denmark)

Otaegui, Amaia Arranz; Richter, Tobias

-woody plant analyses from two in situ hearth structures, along with a summary of the available evidence at other contemporary early Natufian sites. In terms of past vegetation, the results show the presence of wetland species indicating a more forested and wet environment during the early Natufian, which...

Mega-geomorphology: Mars vis a vis Earth

Science.gov (United States)

Sharp, R. P.

1985-01-01

The areas of chaotic terrain, the giant chasma of the Valles Marineris region, the complex linear and circular depressions of Labyrinthus Noctis on Mars all suggest the possibility of large scale collapse of parts of the martian crust within equatorial and sub equatorial latitudes. It seems generally accepted that the above features are fossil, being perhaps, more than a billion years old. It is possible that parts of Earth's crust experienced similar episodes of large scale collapse sometime early in the evolution of the planet.

ISS EarthKam: Taking Photos of the Earth from Space

Science.gov (United States)

Haste, Turtle

2008-01-01

NASA is involved in a project involving the International Space Station (ISS) and an Earth-focused camera called EarthKam, where schools, and ultimately students, are allowed to remotely program the EarthKAM to take images. Here the author describes how EarthKam was used to help middle school students learn about biomes and develop their…

Digital Earth - Young generation's comprehension and ideas

Science.gov (United States)

Bandrova, T.; Konecny, M.

2014-02-01

The authors are experienced in working with children and students in the field of early warning and crises management and cartography. All these topics are closely connected to Digital Earth (DE) ideas. On the basis of a questionnaire, the young generation's comprehension of DE concept is clarified. Students from different age groups (from 19 to 36) from different countries and with different social, cultural, economical and political backgrounds are asked to provide definition of DE and describe their basic ideas about meaning, methodology and applications of the concept. The questions aim to discover the young generation's comprehension of DE ideas. They partially cover the newest trends of DE development like social, cultural and environmental issues as well as the styles of new communications (Google Earth, Facebook, LinkedIn, etc.). In order to assure the future development of the DE science, it is important to take into account the young generation's expectations. Some aspects of DE development are considered in the Conclusions.

Age of meteorites, the Moon, the Earth

International Nuclear Information System (INIS)

Ovchinnikova, G.V.; Levskij, L.K.

1987-01-01

Review of modern data on age determination of meteorites and lunar rocks and review of papers dedicted to calculations of the Earth age as well are given. Analysis of the age present values, obtained by different methods of isotopic dating has allowed to build up the global events following succession: ∼ 4.8x10 9 years ago - the beginning of dust component condensation within protosolar cloud; ∼ 4.55x10 9 year - the end of cosmic bodies accretion; (4.5-4.4)x10 9 years - differentiation of large planetray bodies (the Moon, the Mars, the Earth) with isolation of the bed type protocrust. Substance differentiation is not typical for solar system small bodies (asteroid-size bodies). Development of the magnetism of main composition (achondrites) on the surface of these bodies is their peculiarity. Both differentiation and basalt volcanism at early periods of cosmic bodies existance are initiated by exogenous factors. Duration of endogenous basalt volcanism correlates with planetary body size

Annual review of earth and planetary sciences. Volume 8

International Nuclear Information System (INIS)

Donath, F.A.; Stehli, F.G.; Wetherill, G.W.

1980-01-01

Papers are presented on the geochemistry of evaporitic lacustrine deposits, the deformation of mantle rocks, the dynamics of sudden stratospheric warmings, the equatorial undercurrent, geomorphological processes on planetary surfaces, and rare earth elements in petrogenetic studies of igneous systems. Consideration is also given to evolutionary patterns in early Cenozoic animals, the origin and evolution of planetary atmospheres, the moons of Mars, and refractory inclusions in the Allende meteorite

Rare earth germanates

International Nuclear Information System (INIS)

Bondar', I.A.; Vinogradova, N.V.; Dem'yanets, L.N.

1983-01-01

Rare earth germanates attract close attention both as an independent class of compounds and analogues of a widely spread class of natural and synthetic minerals. The methods of rare earth germanate synthesis (solid-phase, hydrothermal) are considered. Systems on the basis of germanium and rare earth oxides, phase diagrams, phase transformations are studied. Using different chemical analysese the processes of rare earth germanate formation are investigated. IR spectra of alkali and rare earth metal germanates are presented, their comparative analysis being carried out. Crystal structures of the compounds, lattice parameters are studied. Fields of possible application of rare earth germanates are shown

Rare earth sulfates

International Nuclear Information System (INIS)

Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

1986-01-01

Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

The COSPAR roadmap on Space-based observation and Integrated Earth System Science for 2016-2025

Science.gov (United States)

Fellous, Jean-Louis

2016-07-01

The Committee on Space Research of the International Council for Science recently commissioned a study group to prepare a roadmap on observation and integrated Earth-system science for the coming ten years. Its focus is on the combined use of observations and modelling to address the functioning, predictability and projected evolution of the Earth system on timescales out to a century or so. It discusses how observations support integrated Earth-system science and its applications, and identifies planned enhancements to the contributing observing systems and other requirements for observations and their processing. The paper will provide an overview of the content of the roadmap. All types of observation are considered in the roadmap, but emphasis is placed on those made from space. The origins and development of the integrated view of the Earth system are outlined, noting the interactions between the main components that lead to requirements for integrated science and modelling, and for the observations that guide and support them. What constitutes an Earth-system model is discussed. Summaries are given of key cycles within the Earth system. The nature of Earth observation and the arrangements for international coordination essential for effective operation of global observing systems are introduced in the roadmap. Instances are given of present types of observation, what is already on the roadmap for 2016-2025 and some of the issues to be faced. The current status and prospects for Earth-system modelling are summarized. Data assimilation is discussed not only because it uses observations and models to generate datasets for monitoring the Earth system and for initiating and evaluating predictions, in particular through reanalysis, but also because of the feedback it provides on the quality of both the observations and the models employed. Finally the roadmap offers a set of concluding discussions covering general developmental needs, requirements for continuity of

The YES Network: IYPE's Motto 'Earth Sciences for Society

Science.gov (United States)

Gonzales, Leila; Keane, Christopher

2010-05-01

The YES Network is an international association of early-career geoscientists who are primarily under the age of 35 years and are currently engaged in the geosciences in organizations from across the world. The YES Network was formed as a result of the International Year of Planet Earth in 2007. The YES Network aims to establish an interdisciplinary global network of individuals committed to solving these challenges, and furthering the IYPE motto of "Earth Sciences for Society". In 2009, in collaboration with the IYPE and under the patronage of UNESCO, the YES Network organized its first international Congress at the China University of Geosciences in Beijing, China. The Congress focused on climate, environmental and geoscience challenges facing today's society, as well as career and academic pathway challenges faced by early-career geoscientists. More than 300 young geoscientists from across the world attended the conference to present their research and participate in the oral, poster, and roundtable symposia. The roundtable symposia engaged senior and early-career geoscientists via presentations, panel discussions, and working group sessions. These symposia were broadcast as ‘live' webinars to increase international participation. As a result, 41 "virtual" participants from 10 countries and 16 "virtual" speakers from 5 countries were able to participate in these discussions. Since October, the YES Network has continued to expand its membership and develop more projects aligned with the "Earth Sciences for Society" motto. The YES Network is continuing to develop its website and social media networks to increase communication between YES Network members on local, regional and international scales, and it is developing resources to aid early-career geoscientists with opportunities for professional development, international collaboration, and involvement in outreach activities. Members of the YES Network are actively forming connections between the YES Network

Observation and integrated Earth-system science: A roadmap for 2016-2025

Science.gov (United States)

Simmons, Adrian; Fellous, Jean-Louis; Ramaswamy, Venkatachalam; Trenberth, Kevin; Asrar, Ghassem; Balmaseda, Magdalena; Burrows, John P.; Ciais, Philippe; Drinkwater, Mark; Friedlingstein, Pierre; Gobron, Nadine; Guilyardi, Eric; Halpern, David; Heimann, Martin; Johannessen, Johnny; Levelt, Pieternel F.; Lopez-Baeza, Ernesto; Penner, Joyce; Scholes, Robert; Shepherd, Ted

2016-05-01

This report is the response to a request by the Committee on Space Research of the International Council for Science to prepare a roadmap on observation and integrated Earth-system science for the coming ten years. Its focus is on the combined use of observations and modelling to address the functioning, predictability and projected evolution of interacting components of the Earth system on timescales out to a century or so. It discusses how observations support integrated Earth-system science and its applications, and identifies planned enhancements to the contributing observing systems and other requirements for observations and their processing. All types of observation are considered, but emphasis is placed on those made from space. The origins and development of the integrated view of the Earth system are outlined, noting the interactions between the main components that lead to requirements for integrated science and modelling, and for the observations that guide and support them. What constitutes an Earth-system model is discussed. Summaries are given of key cycles within the Earth system. The nature of Earth observation and the arrangements for international coordination essential for effective operation of global observing systems are introduced. Instances are given of present types of observation, what is already on the roadmap for 2016-2025 and some of the issues to be faced. Observations that are organised on a systematic basis and observations that are made for process understanding and model development, or other research or demonstration purposes, are covered. Specific accounts are given for many of the variables of the Earth system. The current status and prospects for Earth-system modelling are summarized. The evolution towards applying Earth-system models for environmental monitoring and prediction as well as for climate simulation and projection is outlined. General aspects of the improvement of models, whether through refining the

UrtheCast Second-Generation Earth Observation Sensors

Science.gov (United States)

Beckett, K.

2015-04-01

UrtheCast's Second-Generation state-of-the-art Earth Observation (EO) remote sensing platform will be hosted on the NASA segment of International Space Station (ISS). This platform comprises a high-resolution dual-mode (pushbroom and video) optical camera and a dual-band (X and L) Synthetic Aperture RADAR (SAR) instrument. These new sensors will complement the firstgeneration medium-resolution pushbroom and high-definition video cameras that were mounted on the Russian segment of the ISS in early 2014. The new cameras are expected to be launched to the ISS in late 2017 via the Space Exploration Technologies Corporation Dragon spacecraft. The Canadarm will then be used to install the remote sensing platform onto a CBM (Common Berthing Mechanism) hatch on Node 3, allowing the sensor electronics to be accessible from the inside of the station, thus limiting their exposure to the space environment and allowing for future capability upgrades. The UrtheCast second-generation system will be able to take full advantage of the strengths that each of the individual sensors offers, such that the data exploitation capabilities of the combined sensors is significantly greater than from either sensor alone. This represents a truly novel platform that will lead to significant advances in many other Earth Observation applications such as environmental monitoring, energy and natural resources management, and humanitarian response, with data availability anticipated to begin after commissioning is completed in early 2018.

Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

Science.gov (United States)

Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

2015-01-01

Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

An operationally simple method for separating the rare-earth elements neodymium and dysprosium

Energy Technology Data Exchange (ETDEWEB)

Bogart, Justin A.; Lippincott, Connor A.; Carroll, Patrick J.; Schelter, Eric J. [Department of Chemistry, University of Pennsylvania, Philadelphia, PA (United States)

2015-07-06

Rare-earth metals are critical components of electronic materials and permanent magnets. Recycling of consumer materials is a promising new source of rare earths. To incentivize recycling there is a clear need for simple methods for targeted separations of mixtures of rare-earth metal salts. Metal complexes of a tripodal nitroxide ligand [{(2-"tBuNO)C_6H_4CH_2}{sub 3}N]{sup 3-} (TriNOx{sup 3-}), feature a size-sensitive aperture formed of its three η{sup 2}-(N,O) ligand arms. Exposure of metal cations in the aperture induces a self-associative equilibrium comprising [M(TriNOx)thf]/[M(TriNOx)]{sub 2} (M=rare-earth metal). Differences in the equilibrium constants (K{sub eq}) for early and late metals enables simple Nd/Dy separations through leaching with a separation ratio S{sub Nd/Dy}=359. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Earth System Monitoring Selected Entries from the Encyclopedia of Sustainability Science and Technology

CERN Document Server

2013-01-01

Modern Earth System Monitoring represents a fundamental change in the way scientists study the Earth System.  In Oceanography, for the past two centuries, ships have provided the platforms for observing.  Expeditions on the continents and Earth’s poles are land-based analogues. Fundamental understanding of current systems, climate, natural hazards, and ecosystems has been greatly advanced. While these approaches have been remarkably successful, the need to establish measurements over time can only be made using Earth observations and observatories with exacting standards and continuous data.  The 19 peer-reviewed contributions in this volume provide early insights into this emerging view of Earth in both space and time in which change is a critical component of our growing understanding. Presents 19 authoritative, peer-reviewed entries from the Encyclopedia of Sustainability Science and Technology Covers a wide range of data collection platforms, including satellite remote sensing, aerial surveys, and l...

USERDA computer software summaries: numbers 240 through 324

International Nuclear Information System (INIS)

1976-12-01

Since 1960 the Argonne Code Center has served as a U.S. Atomic Energy Commission information center for computer programs developed and used primarily for the solution of problems in nuclear physics, reactor design, reactor engineering and operation. The Center, through a network of registered installations, collects, validates, maintains, and distributes a library of these computer programs and publishes a compilation of abstracts describing them. In 1972 the scope of the Center's activities was officially expanded to include computer programs developed in all of the U.S. Atomic Energy Commission program areas and the compilation and publicatuon of this report. The Computer Software Summary report contains summaries of computer programs at the specification stage, under development, being checked out, in use, or available at ERDA offices, laboratories, and contractor installations. Programs are divided into the following categories : cross section and resonance integral calculations; spectrum calculations, generation of group constants, lattice and cell problems; static design studies; depletion, fuel management, cost analysis, and reactor economics; space-independent k;inetics; pace--time kinetics, coupled neutronics--hydrodynamics--thermodynmics and excursion simulations; radiological safety, hazard and accident analysis; heat transfer and fluid flow; deformation and stress distribution computations, structural analysis and engineering design studies; gamma heating and shielddesign programs; reactor systems analysis; data preparation; data management; subsidiary calculations; experimental data processing; general mathematical and computing system routines; materials; environmental and earth sciences; space sciences; electronics and engineering equipment; chemistry; particle accelerators and high-voltage machines; physics; controlled thermonuclear research; biology and medicine; and data

Prospect of Continuous VLBI Measurement of Earth Rotation in Monitoring Geophysical Fluids

Science.gov (United States)

Chao, Benjamin F.; Ma, Chopo; Clark, Thomas

1998-01-01

Large-scale mass transports in the geophysical fluids of the Earth system excite Earth's rotational variations in both length-of-day and polar motion. The excitation process is via the conservation of angular momentum. Therefore Earth rotation observations contain information about the integrated angular momentum (consisting of both the mass term and the motion term) of the geophysical fluids, which include atmosphere, hydrosphere, mantle, and the outer and inner cores. Such global information is often important and otherwise unattainable depending on the nature of the mass transport, its magnitude and time scale. The last few years have seen great advances in VLBI measurement of Earth rotation in precision and temporal resolution. These advances have opened new. areas in geophysical fluid studies, such as oceanic tidal angular momentum, atmospheric tides, Earth librations, and rapid atmospheric angular momentum fluctuations. Precision of 10 microseconds in UTI and 200 microarcseconds in polar motion can now be achieved on hourly basis. Building upon this heritage, the multi-network geodetic VLBI project, Continuous Observation of the Rotation of the Earth (CORE), promises to further these studies and to make possible studies on elusive but tell-tale geophysical processes such as oscillatory modes in the core and in the atmosphere. Currently the early phase of CORE is underway. Within a few years into the new mellinnium, the upcoming space gravity missions (such as GRACE) will measure the temporal variations in Earth's gravitational field, thus providing complementary information to that from Earth rotation study for a better understanding of global geophysical fluid processes.

Summaries of physical research in the geosciences

International Nuclear Information System (INIS)

1978-09-01

The Department of Energy supports research in the geosciences in order to provide a sound underlay of fundamental knowledge in those areas of the earth, atmospheric, and solar/terrestrial sciences which relate to DOE's many missions. This research may be conducted in the major DOE laboratories, industry, universities and other government agencies. Such support provides for payment of salaries, purchase of equipment and other materials, an allowance for overhead costs, and is formalized by a contract between the Department and the organization performing the work. The summaries in this document, prepared by the investigators, describe the work performed during 1977, include the scope of the work to be performed in 1978 and provide information regarding some of the research planned for 1979. The Division of Engineering, Mathematics, and Geosciences, which is a part of the Office of Energy Research, supports, under its Geoscience Program, research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology and natural resource analysis, including the various subdivisions and interdisciplinary relationships, as well as their relationship to the Department's technological needs

Digital Earth – A sustainable Earth

International Nuclear Information System (INIS)

Mahavir

2014-01-01

All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth

Mirror Confinement Systems: project summaries

International Nuclear Information System (INIS)

1980-07-01

This report contains descriptions of the projects supported by the Mirror Confinement Systems (MCS) Division of the Office of Fusion Energy. The individual project summaries were prepared by the principal investigators, in collaboration with MCS staff office, and include objectives and milestones for each project. In addition to project summaries, statements of Division objectives and budget summaries are also provided

Why Earth Science?

Science.gov (United States)

Smith, Michael J.

2004-01-01

This article briefly describes Earth science. The study of Earth science provides the foundation for an understanding of the Earth, its processes, its resources, and its environment. Earth science is the study of the planet in its entirety, how its lithosphere, atmosphere, hydrosphere, and biosphere work together as systems and how they affect…

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn

2015-03-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth\\'s magnetic field system.

Neutron activation analysis of rare earths and some other elements in material of geochemical interest

International Nuclear Information System (INIS)

Brunfelt, A.O.

1975-01-01

ngle-element methods for the determination by neutron activation analysis of antimony, chromium, phosphorus, selenium and silver in international geochemical standard rocks, and the determination of rare earth elements i in standard rocks and apatites are described and discussed in twelve previously published papers, and in an eighteen page summary. Chemical separationtechniques are also discussed and the results are compared with previously obtained results with the same standard rocks. The accuracy of neutron activation analysis is discussed in comparison with isotope dilution mass spectroscopy, atomic absorption, gas chromatography and spark source mass spectrometry. (JIW)

EarthConnections: Integrating Community Science and Geoscience Education Pathways for More Resilient Communities.

Science.gov (United States)

Manduca, C. A.

2017-12-01

To develop a diverse geoscience workforce, the EarthConnections collective impact alliance is developing regionally focused, Earth education pathways. These pathways support and guide students from engagement in relevant, Earth-related science at an early age through the many steps and transitions to geoscience-related careers. Rooted in existing regional activities, pathways are developed using a process that engages regional stakeholders and community members with EarthConnections partners. Together they connect, sequence, and create multiple learning opportunities that link geoscience education and community service to address one or more local geoscience issues. Three initial pilots are demonstrating different starting points and strategies for creating pathways that serve community needs while supporting geoscience education. The San Bernardino pilot is leveraging existing academic relationships and programs; the Atlanta pilot is building into existing community activities; and the Oklahoma Tribal Nations pilot is co-constructing a pathway focus and approach. The project is using pathway mapping and a collective impact framework to support and monitor progress. The goal is to develop processes and activities that can help other communities develop similar community-based geoscience pathways. By intertwining Earth education with local community service we aspire to increase the resilience of communities in the face of environmental hazards and limited Earth resources.

Summary

International Nuclear Information System (INIS)

2004-01-01

The fourth workshop of the OECD/NEA Forum on Stakeholder Confidence (FSC) was hosted by ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste Management and enriched fissile materials. The central theme of the workshop was ''Dealing with interests, values and knowledge in managing risk''within the Belgian context of local partnerships for the long term management of low-level, short-lived radioactive waste. The four-day workshop started with a half-day session in Brussels giving a general introduction on the Belgian context and the local partnership methodology. This was followed by community visits to three local partnerships, PaLoFF in Fleurus-Farciennes, MONA in Mol, and STOLA in Dessel. After the visits, the workshop continued with two full-day sessions in Brussels. One hundred and nineteen registered participants, representing 13 countries, attended the workshop or participated in the community visits. About two thirds were Belgian stakeholders; the remainder came from FSC member organisations. The participants included representatives of municipal governments, civil society organisations, government agencies, industrial companies, the media, and international organisations as well as private citizens, consultants and academics. This Executive Summary gives an overview of the presentations and discussions that took place at the workshop and the community visits. The structure of the Executive Summary follows the structure of the workshop itself. Complementary to this Executive Summary and also provided with this document, is a NEA Secretariat's reflection aiming to place the main lessons of the workshop into an international perspective. (author)

Evolution of the Oxidation State of the Earth's Mantle

Science.gov (United States)

Danielson, L. R.; Righter, K.; Keller, L.; Christoffersen, E.; Rahman, Z.

2015-01-01

The oxidation state of the Earth's mantle during formation remains an unresolved question, whether it was constant throughout planetary accretion, transitioned from reduced to oxidized, or from oxidized to reduced. We investigate the stability of Fe3(+) at depth, in order to constrain processes (water, late accretion, dissociation of FeO) which may reduce or oxidize the Earth's mantle. In our previous experiments on shergottite compositions, variable fO2, T, and P less than 4 GPa, Fe3(+)/sigma Fe decreased slightly with increasing P, similar to terrestrial basalt. For oxidizing experiments less than 7GPa, Fe3(+)/sigma Fe decreased as well, but it's unclear from previous modelling whether the deeper mantle could retain significant Fe3(+). Our current experiments expand our pressure range deeper into the Earth's mantle and focus on compositions and conditions relevant to the early Earth. Preliminary multi-anvil experiments with Knippa basalt as the starting composition were conducted at 5-7 GPa and 1800 C, using a molybdenum capsule to set the fO2 near IW, by buffering with Mo-MoO3. TEM and EELS analyses revealed the run products quenched to polycrystalline phases, with the major phase pyroxene containing approximately equal to Fe3(+)/2(+). Experiments are underway to produce glassy samples that can be measured by EELS and XANES, and are conducted at higher pressures.

Earth Rotation

Science.gov (United States)

Dickey, Jean O.

1995-01-01

The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

THE NASA-UC ETA-EARTH PROGRAM. III. A SUPER-EARTH ORBITING HD 97658 AND A NEPTUNE-MASS PLANET ORBITING Gl 785

International Nuclear Information System (INIS)

Howard, Andrew W.; Marcy, Geoffrey W.; Isaacson, Howard; Johnson, John Asher; Fischer, Debra A.; Wright, Jason T.; Henry, Gregory W.; Valenti, Jeff A.; Anderson, Jay; Piskunov, Nikolai E.

2011-01-01

We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modeling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msin i = 8.2 ± 1.2 M + , orbital period P = 9.494 ± 0.005 days, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msin i = 21.6 ± 2.0 M + , P = 74.39 ± 0.12 days, and orbital eccentricity e = 0.30 ± 0.09. Photometric observations with the T12 0.8 m automatic photometric telescope at Fairborn Observatory show that HD 97658 is photometrically constant at the radial velocity period to 0.09 mmag, supporting the existence of the planet.

Green Power Marketing in Retail Competition: An Early Assessment

Energy Technology Data Exchange (ETDEWEB)

Wiser, R. (LBL); Fang, J.; Porter, K.; Houston, A. (NREL)

1999-02-26

Green power marketing-the business of selling electricity products or services based in part on their environmental values-is still in an early stage of development. This Topical Issues Brief presents a summary of early results with green power marketing under retail competition, covering both fully competitive markets and relevant direct access pilot programs. The brief provides an overview of green products that are or were offered, and discusses consumers' interest in these products. Critical issues that will impact the availability and success of green power products under retail competition are highlighted.

Green Power Marketing in Retail Competition: An Early Assessment

International Nuclear Information System (INIS)

Kevin Porter; Ryan Wiser

1999-01-01

Green power marketing-the business of selling electricity products or services based in part on their environmental values-is still in an early stage of development. This Topical Issues Brief presents a summary of early results with green power marketing under retail competition, covering both fully competitive markets and relevant direct access pilot programs. The brief provides an overview of green products that are or were offered, and discusses consumers' interest in these products. Critical issues that will impact the availability and success of green power products under retail competition are highlighted

An Earth-sized planet with an Earth-like density

DEFF Research Database (Denmark)

Pepe, Francesco; Cameron, Andrew Collier; Latham, David W.

2013-01-01

significantly larger than the Earth. Recently, the planet Kepler-78b was discovered(8) and found to have a radius of only 1.16R(circle plus). Here we report that the mass of this planet is 1.86 Earth masses. The resulting mean density of the planet is 5.57 g cm(-3), which is similar to that of the Earth...

Procedure for the separation of cerium from crude phosphates and rare earth concentrates

International Nuclear Information System (INIS)

Richter, H.; Koenig, O.; Schmitt, A.; Grauss, H.; Freitag, S.

1986-01-01

The invention has to do with a procedure for the separation of cerium from crude phosphates and rare earth phosphate concentrates originating from the partial neutralization of nitric crude phosphate decomposition solutions. It is aimed at the cerium separation from the raw material at an early stage of reprocessing without preceding elimination of other components and impurities. The rare earth phosphate concentrates or crude phosphates are dissolved in nitric acid, the Ce 3+ is oxidized with potassium permanganate or magnanese(IV) hydroxide, and cerium(IV) phosphate is precipitated as pure substance by decreasing the acidity of the solution

77 FR 12865 - Enforcement Actions Summary

Science.gov (United States)

2012-03-02

...] Enforcement Actions Summary AGENCY: Transportation Security Administration, DHS. ACTION: Notice of availability. SUMMARY: The Transportation Security Administration (TSA) is providing notice that it has issued an annual summary of all enforcement actions taken by TSA under the authority granted in the...

78 FR 11216 - Enforcement Actions Summary

Science.gov (United States)

2013-02-15

...] Enforcement Actions Summary AGENCY: Transportation Security Administration, DHS. ACTION: Notice of availability. SUMMARY: The Transportation Security Administration (TSA) is providing notice that it has issued an annual summary of all enforcement actions taken by TSA under the authority granted in the...

76 FR 9357 - Enforcement Actions Summary

Science.gov (United States)

2011-02-17

...] Enforcement Actions Summary AGENCY: Transportation Security Administration, DHS. ACTION: Notice of Availability. SUMMARY: The Transportation Security Administration (TSA) is providing notice that it has issued an annual summary of all enforcement actions taken by TSA under the authority granted in the...

The Janus face of iron on anoxic worlds: iron oxides are both protective and destructive to life on the early Earth and present-day Mars.

Science.gov (United States)

Wadsworth, Jennifer; Cockell, Charles S

2017-05-01

The surface of the early Earth was probably subjected to a higher flux of ultraviolet (UV) radiation than today. UV radiation is known to severely damage DNA and other key molecules of life. Using a liquid culture and a rock analogue system, we investigated the interplay of protective and deleterious effects of iron oxides under UV radiation on the viability of the model organism, Bacillus subtilis. In the presence of hydrogen peroxide, there exists a fine balance between iron oxide's protective effects against this radiation and its deleterious effects caused by Photo-Fenton reactions. The maximum damage was caused by a concentration of hematite of ∼1 mg/mL. Concentrations above this confer increasing protection by physical blockage of the UV radiation, concentrations below this cause less effective UV radiation blockage, but also a correspondingly less effective Photo-Fenton reaction, providing an overall advantage. These results show that on anoxic worlds, surface habitability under a high UV flux leaves life precariously poised between the beneficial and deleterious effects of iron oxides. These results have relevance to the Archean Earth, but also the habitability of the Martian surface, where high levels of UV radiation in combination with iron oxides and hydrogen peroxide can be found. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Investigations on fabricating strategies and utilization of rare earth based multicomponent oxide powders in radiation detection

International Nuclear Information System (INIS)

Shinde, Seema; Pitale, S.S.; Banthia, S.; Ghosh, M.; Tyagi, M.; Sen, S.; Gadkari, S.C.

2014-01-01

Materials containing rare earths demonstrate a broad field of applications as high energy radiation detectors, mainly due to their fascinating optical properties. Currently, Ce 3+ -doped rare earth silicates and garnets dominate the scintillator market because they show a high light yield, fast decay time, and high chemical stability. Moreover, the emission wavelength of silicates (410-440 nm) matches the wavelength sensitivity of conventional PMTs while, Si-photo-detector readouts are possible with garnets (emission near 550 nm). The composition, structure and phase of rare earth silicates are rather complex. For example, there are many phases like oxyorthosilicate R 2 SiO 5 , disilicate R 2 Si 2 O 7 , hexagonal R x (SiO 4 ) 6 O 2 oxyapatite etc (where R= Rare earth element). The controlled synthesis of single phase rare earth silicates and garnets nanomaterials is not easy and can only be reached with precisely controlled experimental conditions. In this work, we provide a broad overview of our recent scientific developments linked to a few aspects of synthesizing cerium activated rare earth based silicates and garnet materials, namely Gd 2 SiO 5 :Ce 3+ , Gd 4.67 (SiO 4 ) 3 O, Gd 2 Si 2 O 7 :Ce 3+ and Gd 3 Al x Ga 1-x O 12 :Ce 3+ (where 0≤x≤5) exploiting the advantages of solution combustion, chemical co-precipitation and hydrothermal techniques. A brief summary of results based on synthesis strategy adopted, composition, size shape and corresponding luminescence features of Gd based compounds are tabulated. The room temperature photoluminescence (PL) features of compounds listed. Efforts towards finding new properties and new materials will be continued and several applications, in particular energy-conversion and scintillator detectors, will benefit from these rare earth materials

Studies of Life on Earth are Important for Mars Exploration

Science.gov (United States)

DesMarais, D. J.

1998-01-01

The search for evidence of the early martian environment and a martian biosphere is benefitted by diverse studies of life on Earth. Most fundamentally, origin-of-life research highlights the challenge in formulating a rigorous definition of life. Because such definitions typically list several of life's most basic properties, they also help to define those observable features that distinguish life and thus might be sought through telescopes, spacecraft, and analyses of extraterrestrial samples. Studies of prebiotic chemistry also help by defining the range of environments and processes that sustain prebiotic organic synthesis. These studies might indicate if and where prebiotic processes occur today on Earth and elsewhere. Such studies should also help to identify which localities are good candidates for the origin of life. A better understanding of the most fundamental principles by which molecules are assembled into living systems will help us to appreciate possible alternatives to the path followed by life on Earth. These perspectives will sharpen our ability to recognize exotic life and/or those environments that can sustain it.

Technology thrusts for future Earth science applications

Science.gov (United States)

Habib, Shahid

2001-02-01

This paper presents NASA's recent direction to invest in the critical science instrument and platform technologies in order to realize more reliable, frequent and versatile missions for future Earth Science measurements. Historically, NASA's Earth Science Enterprise has developed and flown science missions that have been large in size, mass and volume. These missions have taken much longer to implement due to technology development time, and have carried a large suite of instruments on a large spacecraft. NASA is now facing an era where the budget for the future years is more or less flat and the possibility for any major new start does not vividly appear on the horizon. Unfortunately, the scientific measurement needs for remote sensing have not shrunk to commensurate with the budget constraints. In fact, the challenges and scientific appetite in search of answers to a score of outstanding questions have been gradually expanding. With these factors in mind, for the last three years NASA has been changing its focus to concentrate on how to take advantage of smaller missions by relying on industry, and minimizing the overall mission life cycle by developing technologies that are independent of the mission implementation cycle. The major redirection of early investment in the critical technologies should eventually have its rewards and significantly reduce the mission development period. Needless to say, in the long run this approach should save money, minimize risk, promote or encourage partnering, allow for a rapid response to measurement needs, and enable frequent missions making a wider variety of earth science measurements. This paper gives an overview of some of the identified crucial technologies and their intended applications for meeting the future Earth Science challenges.

Technology Thrust for Future Earth Science Applications

Science.gov (United States)

Habib, Shahid

2000-01-01

This paper presents NASA's recent direction to invest in the critical science instrument and platform technologies in order to realize more reliable, frequent and versatile missions for future Earth Science measurements. Traditionally, NASA's Earth Science Enterprise has developed and flown science missions that have been large in size, weight and volume. These missions have taken much longer implementation due to technology development time and have carried a large suite of instruments on a large-size spacecraft. NASA is also facing an era where the budget for the future years is more or less flat and the possibility for any major new start does not vividly appear on the horizon. Unfortunately, the scientific goals have not shrunk to commensurate with the budget constraints. In fact, the challenges and scientific appetite in search of answers to a score of outstanding questions have been gradually expanding. With these factors in mind, for the last three years NASA has been changing its focus to concentrate on how to take advantage of smaller missions by relying on industry, and minimizing the overall life cycle by infusing technologies that are being developed independently of any planned mission's implementation cycle. The major redirection of early investment in the critical technologies should have its rewards and significantly reduce the mission development period. Needless to say, in the long run this approach should save money, minimize risk, promote or encourage partnering, and allow for more frequent missions or earth science measurements to occur. This paper gives an overview of some of the identified crucial technologies and their intended applications for meeting the future Earth Science challenges.

19 CFR 210.18 - Summary determinations.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Summary determinations. 210.18 Section 210.18 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Motions § 210.18 Summary determinations. (a) Motions for summary...

A morphogram for silica-witherite biomorphs and its application to microfossil identification in the early earth rock record.

Science.gov (United States)

Rouillard, J; García-Ruiz, J-M; Gong, J; van Zuilen, M A

2018-05-01

Archean hydrothermal environments formed a likely site for the origin and early evolution of life. These are also the settings, however, were complex abiologic structures can form. Low-temperature serpentinization of ultramafic crust can generate alkaline, silica-saturated fluids in which carbonate-silica crystalline aggregates with life-like morphologies can self-assemble. These "biomorphs" could have adsorbed hydrocarbons from Fischer-Tropsch type synthesis processes, leading to metamorphosed structures that resemble carbonaceous microfossils. Although this abiogenic process has been extensively cited in the literature and has generated important controversy, so far only one specific biomorph type with a filamentous shape has been discussed for the interpretation of Archean microfossils. It is therefore critical to precisely determine the full distribution in morphology and size of these biomorphs, and to study the range of plausible geochemical conditions under which these microstructures can form. Here, a set of witherite-silica biomorph synthesis experiments in silica-saturated solutions is presented, for a range of pH values (from 9 to 11.5) and barium ion concentrations (from 0.6 to 40 mmol/L BaCl 2 ). Under these varying conditions, a wide range of life-like structures is found, from fractal dendrites to complex shapes with continuous curvature. The size, spatial concentration, and morphology of the biomorphs are strongly controlled by environmental parameters, among which pH is the most important. This potentially limits the diversity of environments in which the growth of biomorphs could have occurred on Early Earth. Given the variety of the observed biomorph morphologies, our results show that the morphology of an individual microstructure is a poor criterion for biogenicity. However, biomorphs may be distinguished from actual populations of cellular microfossils by their wide, unimodal size distribution. Biomorphs grown by diffusion in silica gel can

Overview of NASA's Earth Science Data Systems

Science.gov (United States)

McDonald, Kenneth

2004-01-01

For over the last 15 years, NASA's Earth Science Enterprise (ESE) has devoted a tremendous effort to design and build the Earth Observing System (EOS) Data and Information System (EOSDIS) to acquire, process, archive and distribute the data of the EOS series of satellites and other ESE missions and field programs. The development of EOSDIS began with an early prototype to support NASA data from heritage missions and progressed through a formal development process to today's system that supports the data from multiple missions including Landsat 7, Terra, Aqua, SORCE and ICESat. The system is deployed at multiple Distributed Active Archive Centers (DAACs) and its current holdings are approximately 4.5 petabytes. The current set of unique users requesting EOS data and information products exceeds 2 million. While EOSDIS has been the centerpiece of NASA's Earth Science Data Systems, other initiatives have augmented the services of EOSDIS and have impacted its evolution and the future directions of data systems within the ESE. ESDIS had an active prototyping effort and has continued to be involved in the activities of the Earth Science Technology Office (ESTO). In response to concerns from the science community that EOSDIS was too large and monolithic, the ESE initiated the Earth Science Information Partners (ESP) Federation Experiment that funded a series of projects to develop specialized products and services to support Earth science research and applications. Last year, the enterprise made 41 awards to successful proposals to the Research, Education and Applications Solutions Network (REASON) Cooperative Agreement Notice to continue and extend the ESP activity. The ESE has also sponsored a formulation activity called the Strategy for the Evolution of ESE Data Systems (SEEDS) to develop approaches and decision support processes for the management of the collection of data system and service providers of the enterprise. Throughout the development of its earth science

EarthLabs - Investigating Hurricanes: Earth's Meteorological Monsters

Science.gov (United States)

McDaris, J. R.; Dahlman, L.; Barstow, D.

2007-12-01

Earth science is one of the most important tools that the global community needs to address the pressing environmental, social, and economic issues of our time. While, at times considered a second-rate science at the high school level, it is currently undergoing a major revolution in the depth of content and pedagogical vitality. As part of this revolution, labs in Earth science courses need to shift their focus from cookbook-like activities with known outcomes to open-ended investigations that challenge students to think, explore and apply their learning. We need to establish a new model for Earth science as a rigorous lab science in policy, perception, and reality. As a concerted response to this need, five states, a coalition of scientists and educators, and an experienced curriculum team are creating a national model for a lab-based high school Earth science course named EarthLabs. This lab course will comply with the National Science Education Standards as well as the states' curriculum frameworks. The content will focus on Earth system science and environmental literacy. The lab experiences will feature a combination of field work, classroom experiments, and computer access to data and visualizations, and demonstrate the rigor and depth of a true lab course. The effort is being funded by NOAA's Environmental Literacy program. One of the prototype units of the course is Investigating Hurricanes. Hurricanes are phenomena which have tremendous impact on humanity and the resources we use. They are also the result of complex interacting Earth systems, making them perfect objects for rigorous investigation of many concepts commonly covered in Earth science courses, such as meteorology, climate, and global wind circulation. Students are able to use the same data sets, analysis tools, and research techniques that scientists employ in their research, yielding truly authentic learning opportunities. This month-long integrated unit uses hurricanes as the story line by

Early Detection of Sporadic Pancreatic Cancer

Science.gov (United States)

Chari, Suresh T.; Kelly, Kimberly; Hollingsworth, Michael A.; Thayer, Sarah P.; Ahlquist, David A.; Andersen, Dana K.; Batra, Surinder K.; Brentnall, Teresa A.; Canto, Marcia; Cleeter, Deborah F.; Firpo, Matthew A.; Gambhir, Sanjiv Sam; Go, Vay Liang W.; Hines, O. Joe; Kenner, Barbara J.; Klimstra, David S.; Lerch, Markus M.; Levy, Michael J.; Maitra, Anirban; Mulvihill, Sean J.; Petersen, Gloria M.; Rhim, Andrew D.; Simeone, Diane M.; Srivastava, Sudhir; Tanaka, Masao; Vinik, Aaron I.; Wong, David

2015-01-01

Abstract Pancreatic cancer (PC) is estimated to become the second leading cause of cancer death in the United States by 2020. Early detection is the key to improving survival in PC. Addressing this urgent need, the Kenner Family Research Fund conducted the inaugural Early Detection of Sporadic Pancreatic Cancer Summit Conference in 2014 in conjunction with the 45th Anniversary Meeting of the American Pancreatic Association and Japan Pancreas Society. This seminal convening of international representatives from science, practice, and clinical research was designed to facilitate challenging interdisciplinary conversations to generate innovative ideas leading to the creation of a defined collaborative strategic pathway for the future of the field. An in-depth summary of current efforts in the field, analysis of gaps in specific areas of expertise, and challenges that exist in early detection is presented within distinct areas of inquiry: Case for Early Detection: Definitions, Detection, Survival, and Challenges; Biomarkers for Early Detection; Imaging; and Collaborative Studies. In addition, an overview of efforts in familial PC is presented in an addendum to this article. It is clear from the summit deliberations that only strategically designed collaboration among investigators, institutions, and funders will lead to significant progress in early detection of sporadic PC. PMID:25931254

Summary of blog

CERN Document Server

Reader, Capitol

2013-01-01

This ebook consists of a summary of the ideas, viewpoints and facts presented by Hugh Hewitt in his book "Blog: Understanding the Information Reformation that's Changing Your World". This summary offers a concise overview of the entire book in less than 30 minutes reading time. However this work does not replace in any case Hugh Hewitt's book.Hewitt argues that blogs have an important potential and he believes that it would be a dreadful mistake to avoid their power.

Making Nature's Wisdom Public: The Affirmation of Planet Earth as a Living Organism.

Science.gov (United States)

Cohen, Michael J.

Planet Earth is a living organism that preserves and regenerates itself and shares information with humans through sensations, feelings, and actions. After early humans migrated from their tropical origins to colder climates, they developed technologies to impose their tropical memories on their new surroundings and lost touch with their ancient…

Red-emitting alkaline-earth rare-earth pentaoxometallates powders ...

Indian Academy of Sciences (India)

Moisture-insensitive metal carboxylates that are mostly liquids at room temperature have been first applied to ... alkaline-earth ion, or possibly even a rare-earth ion and alkali metal ... sion spectra of the powders were recorded on a fluorescent.

Volatile elements - water, carbon, nitrogen, noble gases - on Earth

Science.gov (United States)

Marty, B.

2017-12-01

Understanding the origin and evolution of life-bearing volatile elements (water, carbon, nitrogen) on Earth is a fruitful and debated area of research. In his pioneering work, W.W. Rubey inferred that the terrestrial atmosphere and the oceans formed from degassing of the mantle through geological periods of time. Early works on noble gas isotopes were consistent with this view and proposed a catastrophic event of mantle degassing early in Earth's history. We now have evidence, mainly from noble gas isotopes, that several cosmochemical sources contributed water and other volatiles at different stages of Earth's accretion. Potential contributors include the protosolar nebula gas that equilibrated with magma oceans, inner solar system bodies now represented by chondrites, and comets. Stable isotope ratios suggest volatiles where primarily sourced by planetary bodies from the inner solar system. However, recent measurements by the European Space Agency Rosetta probe on the coma of Comet 67P/Churyumov-Gerasimenko permit to set quantitative constraints on the cometary contribution to the surface of our planet. The surface and mantle reservoirs volatile elements exchanged volatile elements through time, with rates that are still uncertain. Some mantle regions remained isolated from whole mantle convection within the first tens to hundreds million years after start of solar system formation. These regions, now sampled by some mantle plumes (e.g., Iceland, Eifel) preserved their volatile load, as indicated by extinct and extant radioactivity systems. The abundance of volatile elements in the mantle is still not well known. Different approaches, such as high pressure experimental petrology, noble gas geochemistry, modelling, resulted in somewhat contrasted estimates, varying over one order of magnitude for water. Comparative planetology, that is, the study of volatiles on the Moon, Venus, Mars, Vesta, will shed light on the sources and strengths of these elements in the

Earth - South America (first frame of Earth Spin Movie)

Science.gov (United States)

1990-01-01

This color image of the Earth was obtained by Galileo at about 6:10 a.m. Pacific Standard Time on Dec. 11, 1990, when the spacecraft was about 1.3 million miles from the planet during the first of two Earth flybys on its way to Jupiter. The color composite used images taken through the red, green and violet filters. South America is near the center of the picture, and the white, sunlit continent of Antarctica is below. Picturesque weather fronts are visible in the South Atlantic, lower right. This is the first frame of the Galileo Earth spin movie, a 500- frame time-lapse motion picture showing a 25-hour period of Earth's rotation and atmospheric dynamics.

Two different sources of water for the early solar nebula.

Science.gov (United States)

Kupper, Stefan; Tornow, Carmen; Gast, Philipp

2012-06-01

Water is essential for life. This is a trivial fact but has profound implications since the forming of life on the early Earth required water. The sources of water and the related amount of delivery depend not only on the conditions on the early Earth itself but also on the evolutionary history of the solar system. Thus we ask where and when water formed in the solar nebula-the precursor of the solar system. In this paper we explore the chemical mechanics for water formation and its expected abundance. This is achieved by studying the parental cloud core of the solar nebula and its gravitational collapse. We have identified two different sources of water for the region of Earth's accretion. The first being the sublimation of the icy mantles of dust grains formed in the parental cloud. The second source is located in the inner region of the collapsing cloud core - the so-called hot corino with a temperature of several hundred Kelvin. There, water is produced efficiently in the gas phase by reactions between neutral molecules. Additionally, we analyse the dependence of the production of water on the initial abundance ratio between carbon and oxygen.

TravelingGeologist: an online platform for dissemination of earth science to the masses

Science.gov (United States)

Spencer, C. J.; Hoiland, C. W.; Gunderson, K. L.

2016-12-01

To more effectively inspire the next generation of scientists, the earth science community's public outreach efforts must adapt to the changing technological and informational ecosystems in which young people interact online (e.g. blogs, social media, viral marketing, web-based education, etc.). Although there are currently a number of successful individual and institutional efforts to reach potential students through web-based outlets, many of these efforts fail to connect primary researchers directly to a lay audience, relying instead on intermediaries that tend to dilute the recruiting impact of "producer-to-consumer" interactions. Few, if any of these efforts appear to have reached a critical mass of contributing authors and subscribed followers; and there are few available detailed metrics on growth trajectories, impact, or lay reach. We offer data from the TravelingGeologist as a case study in successful direct-to-consumer science outreach and recruitment. The TravelingGeologist is a non-profit, web-based platform on which earth scientists share their experiences in the field with the expressed purpose of attracting and inspiring a new generation of scientists. The TravelingGeologist website is supplemented by various social media platforms that market the content on the main site. Because TravelingGeologist accepts contributions from a variety of earth scientists, it also provides an arena whereon research summaries and vignettes can be shared with the large lay- and expert audience. This gives contributing authors an additional opportunity to demonstrate to government institutions that fund their research projects that they are engaging in efforts to communicate their results to the wider public. Beyond the ability to inspire new students and communicate science to the general public, it is our intent that TravelingGeologist will foster communication and promote collaboration within the earth science community. We have demonstrated that through well

Early solar system. Early accretion of water in the inner solar system from a carbonaceous chondrite-like source.

Science.gov (United States)

Sarafian, Adam R; Nielsen, Sune G; Marschall, Horst R; McCubbin, Francis M; Monteleone, Brian D

2014-10-31

Determining the origin of water and the timing of its accretion within the inner solar system is important for understanding the dynamics of planet formation. The timing of water accretion to the inner solar system also has implications for how and when life emerged on Earth. We report in situ measurements of the hydrogen isotopic composition of the mineral apatite in eucrite meteorites, whose parent body is the main-belt asteroid 4 Vesta. These measurements sample one of the oldest hydrogen reservoirs in the solar system and show that Vesta contains the same hydrogen isotopic composition as that of carbonaceous chondrites. Taking into account the old ages of eucrite meteorites and their similarity to Earth's isotopic ratios of hydrogen, carbon, and nitrogen, we demonstrate that these volatiles could have been added early to Earth, rather than gained during a late accretion event. Copyright © 2014, American Association for the Advancement of Science.

The Benefits of Peer-to-Peer Mentoring: Lessons from The Earth Science Women's Network (ESWN)

Science.gov (United States)

Holloway, T.; Steiner, A.; Fiore, A.; Hastings, M.; McKinley, G.; Staudt, A.; Wiedinmyer, C.

2007-12-01

The Earth Science Women's Network (ESWN) is a grassroots organization that began with the meeting of six women graduate students and recent Ph.D.s at the Spring 2002 AGU meeting in Washington, DC. Since then, the group has grown to over 400 members, completely by word of mouth. We provide an informal, peer-to-peer network developed to promote and support careers of women in the Earth sciences. Through the network, women have found jobs, established research collaborations, shared strategies on work/life balance, and built a community stretching around the world. We maintain an email list for members to develop an expanded peer network outside of their own institution, and we have recently launched a co-ed jobs list to benefit the wider geoscience community. We will present a summary of strategies that have been discussed by group members on how to transition to a new faculty position, build a research group, develop new research collaborations, and balance career and family.

Rare earth superlattices

International Nuclear Information System (INIS)

McMorrow, D.F.

1997-01-01

A review is given of recent experiments on the magnetism of rare earth superlattices. Early experiments in this field were concerned mainly with systems formed by combining a magnetic and a non-magnetic element in a superlattice structure. From results gathered on a variety of systems it has been established that the propagation of magnetic order through the non-magnetic spacer can be understood mostly on the basis of an RKKY-like model, where the strength and range of the coupling depends on the details of the conduction electron susceptibility of the spacer. Recent experiments on more complex systems indicate that this model does not provide a complete description. Examples include superlattices where the constituents can either be both magnetic, adopt different crystal structures (Fermi surfaces), or where one of the constituents has a non-magnetic singlet ground state. The results from such systems are presented and discussed in the context of the currently accepted model. (au)

Building a Dashboard of the Planet with Google Earth and Earth Engine

Science.gov (United States)

Moore, R. T.; Hancher, M.

2016-12-01

In 2005 Google Earth, a popular 3-D virtual globe, was first released. Scientists immediately recognized how it could be used to tell stories about the Earth. From 2006 to 2009, the "Virtual Globes" sessions of AGU included innovative examples of scientists and educators using Google Earth, and since that time it has become a commonplace tool for communicating scientific results. In 2009 Google Earth Engine, a cloud-based platform for planetary-scale geospatial analysis, was first announced. Earth Engine was initially used to extract information about the world's forests from raw Landsat data. Since then, the platform has proven highly effective for general analysis of georeferenced data, and users have expanded the list of use cases to include high-impact societal issues such as conservation, drought, disease, food security, water management, climate change and environmental monitoring. To support these use cases, the platform has continuously evolved with new datasets, analysis functions, and user interface tools. This talk will give an overview of the latest Google Earth and Earth Engine functionality that allow partners to understand, monitor and tell stories about of our living, breathing Earth. https://earth.google.com https://earthengine.google.com

29 CFR 1905.41 - Summary decision.

Science.gov (United States)

2010-07-01

... OCCUPATIONAL SAFETY AND HEALTH ACT OF 1970 Summary Decisions § 1905.41 Summary decision. (a) No genuine issue... 29 Labor 5 2010-07-01 2010-07-01 false Summary decision. 1905.41 Section 1905.41 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR RULES OF...

40 CFR 68.155 - Executive summary.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Executive summary. 68.155 Section 68...) CHEMICAL ACCIDENT PREVENTION PROVISIONS Risk Management Plan § 68.155 Executive summary. The owner or operator shall provide in the RMP an executive summary that includes a brief description of the following...

Computerized summary scoring: crowdsourcing-based latent semantic analysis.

Science.gov (United States)

Li, Haiying; Cai, Zhiqiang; Graesser, Arthur C

2017-11-03

In this study we developed and evaluated a crowdsourcing-based latent semantic analysis (LSA) approach to computerized summary scoring (CSS). LSA is a frequently used mathematical component in CSS, where LSA similarity represents the extent to which the to-be-graded target summary is similar to a model summary or a set of exemplar summaries. Researchers have proposed different formulations of the model summary in previous studies, such as pregraded summaries, expert-generated summaries, or source texts. The former two methods, however, require substantial human time, effort, and costs in order to either grade or generate summaries. Using source texts does not require human effort, but it also does not predict human summary scores well. With human summary scores as the gold standard, in this study we evaluated the crowdsourcing LSA method by comparing it with seven other LSA methods that used sets of summaries from different sources (either experts or crowdsourced) of differing quality, along with source texts. Results showed that crowdsourcing LSA predicted human summary scores as well as expert-good and crowdsourcing-good summaries, and better than the other methods. A series of analyses with different numbers of crowdsourcing summaries demonstrated that the number (from 10 to 100) did not significantly affect performance. These findings imply that crowdsourcing LSA is a promising approach to CSS, because it saves human effort in generating the model summary while still yielding comparable performance. This approach to small-scale CSS provides a practical solution for instructors in courses, and also advances research on automated assessments in which student responses are expected to semantically converge on subject matter content.

Observing Human-induced Linkages between Urbanization and Earth's Climate System

Science.gov (United States)

Shepherd, J. Marshall; Jin, Menglin

2004-01-01

Urbanization is one of the extreme cases of land use change. Most of world s population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025, 60% of the world s population will live in cities. Human activity in urban environments also alters atmospheric composition; impacts components of the water cycle; and modifies the carbon cycle and ecosystems. However, our understanding of urbanization on the total Earth-climate system is incomplete. Better understanding of how the Earth s atmosphere-ocean-land-biosphere components interact as a coupled system and the influence of the urban environment on this climate system is critical. The goal of the 2003 AGU Union session Human-induced climate variations on urban areas: From observations to modeling was to bring together scientists from interdisciplinary backgrounds to discuss the data, scientific approaches and recent results on observing and modeling components of the urban environment with the intent of sampling our current stand and discussing future direction on this topic. Herein, a summary and discussion of the observations component of the session are presented.

Inaugeral lecture - Meteorite impacts on Earth and on the Earth ...

African Journals Online (AJOL)

There is some controversial evidence for the theory that the first life on Earth itself may have been transported here on meteorites from Mars. The possibility of a major meteorite impact on Earth in the near future emphasizes the dramatic nature of these recent discoveries, which are having deep impacts in the Earth sciences ...

Autonomous scheduling technology for Earth orbital missions

Science.gov (United States)

Srivastava, S.

1982-01-01

The development of a dynamic autonomous system (DYASS) of resources for the mission support of near-Earth NASA spacecraft is discussed and the current NASA space data system is described from a functional perspective. The future (late 80's and early 90's) NASA space data system is discussed. The DYASS concept, the autonomous process control, and the NASA space data system are introduced. Scheduling and related disciplines are surveyed. DYASS as a scheduling problem is also discussed. Artificial intelligence and knowledge representation is considered as well as the NUDGE system and the I-Space system.

Planetary-Scale Geospatial Data Analysis Techniques in Google's Earth Engine Platform (Invited)

Science.gov (United States)

Hancher, M.

2013-12-01

Geoscientists have more and more access to new tools for large-scale computing. With any tool, some tasks are easy and other tasks hard. It is natural to look to new computing platforms to increase the scale and efficiency of existing techniques, but there is a more exiting opportunity to discover and develop a new vocabulary of fundamental analysis idioms that are made easy and effective by these new tools. Google's Earth Engine platform is a cloud computing environment for earth data analysis that combines a public data catalog with a large-scale computational facility optimized for parallel processing of geospatial data. The data catalog includes a nearly complete archive of scenes from Landsat 4, 5, 7, and 8 that have been processed by the USGS, as well as a wide variety of other remotely-sensed and ancillary data products. Earth Engine supports a just-in-time computation model that enables real-time preview during algorithm development and debugging as well as during experimental data analysis and open-ended data exploration. Data processing operations are performed in parallel across many computers in Google's datacenters. The platform automatically handles many traditionally-onerous data management tasks, such as data format conversion, reprojection, resampling, and associating image metadata with pixel data. Early applications of Earth Engine have included the development of Google's global cloud-free fifteen-meter base map and global multi-decadal time-lapse animations, as well as numerous large and small experimental analyses by scientists from a range of academic, government, and non-governmental institutions, working in a wide variety of application areas including forestry, agriculture, urban mapping, and species habitat modeling. Patterns in the successes and failures of these early efforts have begun to emerge, sketching the outlines of a new set of simple and effective approaches to geospatial data analysis.

Conference summaries

International Nuclear Information System (INIS)

1987-01-01

This volume contains summaries of 28 papers presented at the 27. conference of the Canadian Nuclear Association. These papers discuss the general situation of the Canadian nuclear industry and the CANDU reactor; dialogue with the public; the International Atomic Energy Agency; and economic goals and operating lessons. It also contains summaries of 70 papers presented at the 8. conference of the Canadian Nuclear Society, which discuss plant life extension; safety and the environment; reactor physics; thermalhydraulics; risk assessment; the CANDU spacer location and repositioning project; CANDU operations; safety research after Chernobyl; fuel channels; and nuclear technology developments. The individual papers are also available in INIS-mf--13673 (CNA), and INIS-mf--12909 (CNS). (L.L.)

NASA's Global Change Master Directory: Discover and Access Earth Science Data Sets, Related Data Services, and Climate Diagnostics

Science.gov (United States)

Aleman, Alicia; Olsen, Lola; Ritz, Scott; Morahan, Michael; Cepero, Laurel; Stevens, Tyler

2011-01-01

NASA's Global Change Master Directory provides the scientific community with the ability to discover, access, and use Earth science data, data-related services, and climate diagnostics worldwide. The GCMD offers descriptions of Earth science data sets using the Directory Interchange Format (DIF) metadata standard; Earth science related data services are described using the Service Entry Resource Format (SERF); and climate visualizations are described using the Climate Diagnostic (CD) standard. The DIF, SERF and CD standards each capture data attributes used to determine whether a data set, service, or climate visualization is relevant to a user's needs. Metadata fields include: title, summary, science keywords, service keywords, data center, data set citation, personnel, instrument, platform, quality, related URL, temporal and spatial coverage, data resolution and distribution information. In addition, nine valuable sets of controlled vocabularies have been developed to assist users in normalizing the search for data descriptions. An update to the GCMD's search functionality is planned to further capitalize on the controlled vocabularies during database queries. By implementing a dynamic keyword "tree", users will have the ability to search for data sets by combining keywords in new ways. This will allow users to conduct more relevant and efficient database searches to support the free exchange and re-use of Earth science data. http://gcmd.nasa.gov/

U.S. Annual Climatological Summaries

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Annual Climatological Summary contains historical monthly and annual summaries for over 8000 U.S. locations. Observing stations are located in the United States of...

49 CFR 1150.44 - Caption summary.

Science.gov (United States)

2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Caption summary. 1150.44 Section 1150.44... Exempt Transactions Under 49 U.S.C. 10902 for Class III Rail Carriers § 1150.44 Caption summary. The caption summary must be in the following form. The information symbolized by numbers is identified in the...

In situ dating of the oldest morphological traces of life on Earth

Science.gov (United States)

Fliegel, D.; McLoughlin, N.; Simonetti, A.; de Wit, M.; Furnes, H.

2008-12-01

Sea floor pillow basalts contain tubular and granular bioalteration micro textures in their glassy margins1,2 created by microbes etching the rock3,4, hypothetically to get access to nutrients and electrons donors5. The etched pits in the rock can be regarded as trace fossils6 that later become mineralized by titanite (CaTiSiO5). Such trace fossils are known from recent oceanic crust to some of the oldest preserved Archean ocean floor, in the Barberton greenstone belt (BGB), in S-Africa7. However, the antiquity of BGB trace fossils has been questioned by some since only the host rock was dated until now8. Here, we report for the first time in situ U-Pb radiometric dating of titanite mineralizing the BGB trace fossils using LA-MC-ICPMS. An U-Pb date of of approx. 3.15 ± 0.05 Ga (95.4 % confidence) for the titanite demonstrates the antiquity of the BGB trace fossils. This result confirms the BGB trace fossils as the oldest directly dated morphological trace of life on Earth. We will present addition data to reveal the mineralization of trace fossils by titanite, comparing the BGB trace fossils to other similar tubular titanite mineralized textures from different locations and younger ages. Our data confirms that a sub-oceanic biosphere was already established in the early Archean by at least 3.2 Ga. Further the results highlight the importance of the sub-ocean habitats for the development and possibly refuge for life on (early) Earth. 1. Furnes, H. et al. Bioalteration of basaltic glass in the oceanic crust. Geochemistry Geophysics Geosystems 2, (2001). 2. Staudigel, H. et al. 3.5 billion years of glass bioalteration: vulcanic rocks as a basis for microbial life. Earth-Science Reviews 89, 156-176 (2008). 3. Furnes, H. et al. Links Between Geological Processes, Microbial Activeties and Evolution of Life. Dilek, Y., Furnes, H. and Muehlenbachs, K. (eds.), pp. 1-68 (Springer,2008). 4. McLoughlin, N. et al. Current Developments in Bioerosion (Erlangen Earth Conference

Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

Science.gov (United States)

West, Phillip B [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID; Wright, Jerry P [Idaho Falls, ID

2011-09-27

Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

29 CFR 1904.32 - Annual summary.

Science.gov (United States)

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false Annual summary. 1904.32 Section 1904.32 Labor Regulations... Requirements § 1904.32 Annual summary. (a) Basic requirement. At the end of each calendar year, you must: (1... deficiencies identified; (2) Create an annual summary of injuries and illnesses recorded on the OSHA 300 Log...

The computational future for climate and Earth system models: on the path to petaflop and beyond.

Science.gov (United States)

Washington, Warren M; Buja, Lawrence; Craig, Anthony

2009-03-13

The development of the climate and Earth system models has had a long history, starting with the building of individual atmospheric, ocean, sea ice, land vegetation, biogeochemical, glacial and ecological model components. The early researchers were much aware of the long-term goal of building the Earth system models that would go beyond what is usually included in the climate models by adding interactive biogeochemical interactions. In the early days, the progress was limited by computer capability, as well as by our knowledge of the physical and chemical processes. Over the last few decades, there has been much improved knowledge, better observations for validation and more powerful supercomputer systems that are increasingly meeting the new challenges of comprehensive models. Some of the climate model history will be presented, along with some of the successes and difficulties encountered with present-day supercomputer systems.

The Lifeworld Earth and a Modelled Earth

Science.gov (United States)

Juuti, Kalle

2014-01-01

The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

Two-way feedback between biology and deep Earth processes

DEFF Research Database (Denmark)

Sleep, Norman; Bird, Dennis K.; Pope, Emily Catherine

The presence of the metamorphic products of banded iron formation and black shale indicate that the Earth teemed with life by the time of the earliest preserved rocks, ca. 3.85 Ga. Iron and sulfur-based anoxygenic photosynthesis with full carbon cycles was present by this time. The pH of the ocean...... was ~8. The lack of older rock record cloaks pre-biotic evolution and the origin of life. Nascent and early life obtained energy from chemical disequilibria in rocks rather than sunlight. Appraising putative rock pre-biological environments is difficult in that life has modified the composition...... of the atmosphere, the hydrosphere, and sedimentary rocks. It has greatly affected the composition of crystalline crustal rocks and measurably modified the mantle. Conversely, hard crustal rocks and the mantle likely sequester a very ancient record of last resort. Theory provides additional insight. The Earth...

Tidal effects on Earth, Planets, Sun by far visiting moons

Science.gov (United States)

Fargion, Daniele

2016-07-01

The Earth has been formed by a huge mini-planet collision forming our Earth surface and our Moon today. Such a central collision hit was statistically rare. A much probable skimming or nearby encounter by other moons or planets had to occur. Indeed Recent observations suggest that many planetary-mass objects may be present in the outer solar system between the Kuiper belt and the Oort cloud. Gravitational perturbations may occasionally bring them into the inner solar system. Their passage near Earth could have generated gigantic tidal waves, large volcanic eruptions, sea regressions, large meteoritic impacts and drastic changes in global climate. They could have caused the major biological mass extinctions in the past in the geological records. For instance a ten times a terrestrial radius nearby impact scattering by a peripherical encounter by a small moon-like object will force huge tidal waves (hundred meter height), able to lead to huge tsunami and Earth-quake. Moreover the historical cumulative planet hits in larger and wider planets as Juppiter, Saturn, Uranus will leave a trace, as observed, in their tilted spin axis. Finally a large fraction of counter rotating moons in our solar system probe and test such a visiting mini-planet captur origination. In addition the Earth day duration variability in the early past did show a rare discountinuity, very probably indebt to such a visiting planet crossing event. These far planets in rare trajectory to our Sun may, in thousands event capture, also explain sudden historical and recent temperature changes.

76 FR 81430 - Small Business Investment Companies-Early Stage SBICs; Public Webinars

Science.gov (United States)

2011-12-28

... SMALL BUSINESS ADMINISTRATION 13 CFR Part 107 Small Business Investment Companies--Early Stage SBICs; Public Webinars AGENCY: U.S. Small Business Administration. ACTION: Notice of public Webinars. SUMMARY: The U.S. Small Business Administration (SBA) announces that it is holding a series of public...

The recent development of efficient Earth-abundant transition-metal nanocatalysts.

Science.gov (United States)

Wang, Dong; Astruc, Didier

2017-02-06

Whereas noble metal compounds have long been central in catalysis, Earth-abundant metal-based catalysts have in the same time remained undeveloped. Yet the efficacy of Earth-abundant metal catalysts was already shown at the very beginning of the 20th century with the Fe-catalyzed Haber-Bosch process of ammonia synthesis and later in the Fischer-Tropsch reaction. Nanoscience has revolutionized the world of catalysis since it was observed that very small Au nanoparticles (NPs) and other noble metal NPs are extraordinarily efficient. Therefore the development of Earth-abundant metals NPs is more recent, but it has appeared necessary due to their "greenness". This review highlights catalysis by NPs of Earth-abundant transition metals that include Mn, Fe, Co, Ni, Cu, early transition metals (Ti, V, Cr, Zr, Nb and W) and their nanocomposites with emphasis on basic principles and literature reported during the last 5 years. A very large spectrum of catalytic reactions has been successfully disclosed, and catalysis has been examined for each metal starting with zero-valent metal NPs followed by oxides and other nanocomposites. The last section highlights the catalytic activities of bi- and trimetallic NPs. Indeed this later family is very promising and simultaneously benefits from increased stability, efficiency and selectivity, compared to monometallic NPs, due to synergistic substrate activation.

Atmospheric acceleration and Earth-expansion deceleration of the Earth rotation

Directory of Open Access Journals (Sweden)

Wenbin Shen

2017-11-01

Full Text Available Previous studies suggest that tidal friction gives rise to the secular deceleration of the Earth rotation by a quantity of about 2.25 ms/cy. Here we just consider additional contributions to the secular Earth rotation deceleration. Atmospheric solar semi-diurnal tide has a small amplitude and certain amount of phase lead. This periodic global air-mass excess distribution exerts a quasi-constant torque to accelerate the Earth's spin rotation. Using an updated atmospheric tide model, we re-estimate the amounts of this atmospheric acceleration torque and corresponding energy input, of which the associated change rate in LOD (length of day is −0.1 ms/cy. In another aspect, evidences from space-geodesy and sea level rise observations suggest that Earth expands at a rate of 0.35 mm/yr in recent decades, which gives rise to the increase of LOD at rate of 1.0 ms/cy. Hence, if the previous estimate due to the tidal friction is correct, the secular Earth rotation deceleration due to tidal friction and Earth expansion should be 3.15 ms/cy.

Statistical summary 1990-91

International Nuclear Information System (INIS)

1991-01-01

The information contained in this statistical summary leaflet summarizes in bar charts or pie charts Nuclear Electric's performance in 1990-91 in the areas of finance, plant and plant operations, safety, commercial operations and manpower. It is intended that the information will provide a basis for comparison in future years. The leaflet also includes a summary of Nuclear Electric's environmental policy statement. (UK)

Indexing for summary queries

DEFF Research Database (Denmark)

Yi, Ke; Wang, Lu; Wei, Zhewei

2014-01-01

), of a particular attribute of these records. Aggregation queries are especially useful in business intelligence and data analysis applications where users are interested not in the actual records, but some statistics of them. They can also be executed much more efficiently than reporting queries, by embedding...... returned by reporting queries. In this article, we design indexing techniques that allow for extracting a statistical summary of all the records in the query. The summaries we support include frequent items, quantiles, and various sketches, all of which are of central importance in massive data analysis....... Our indexes require linear space and extract a summary with the optimal or near-optimal query cost. We illustrate the efficiency and usefulness of our designs through extensive experiments and a system demonstration....

Summary of Meson'98 Workshop

International Nuclear Information System (INIS)

Henley, E.M.

1998-01-01

One never quite knows what to say in a summary. If you were at the sessions, you heard the same talks I did. Perhaps the purpose is to summarize the parallel sessions, but like you, I can only attend one of these sessions. In addition, the time is short, so that this cannot be a real summary. What I will present are impressions of the past two days, and these will certainly be colored by my own views. Thus at the outset, let me apologize for any and all omissions and distortions. I will cover primarily the plenary session talks, but will organize this summary along the following lines: 1. vector (V) mesons; 2. pseudoscalar mesons, and 3. other subjects, notably with electrons. This afternoon's talks are so close in time to this summary that I shall omit them. (author)

Rare earths

International Nuclear Information System (INIS)

1984-01-01

The conference was held from September 12 to 13, 1984 in Jetrichovice, Czechoslovakia. The participants heard 16 papers of which 4 were inputted in INIS. These papers dealt with industrial separation processes of rare earths, the use of chemical methods of separation from the concentrate of apatite and bastnesite, the effect of the relative permittivity of solvents in the elution of rare earth elements from a cation exchanger, and the determination of the content of different rare earth elements using X-ray fluorescence analysis and atomic absorption spectroscopy. (E.S.)

Proceedings of the national conference on rare earth processing and utilization - 2014: abstracts

International Nuclear Information System (INIS)

Anitha, M.; Dasgupta, Kinshuk; Singh, D.K.

2014-01-01

The rare earth elements (REEs) are becoming increasingly important in the transition to a low-carbon, circular economy, considering their essential role in permanent magnets, lamp phosphors, rechargeable nickel metal hydride batteries and catalysts and other green applications. The increasing popularity of hybrid and electric cars, wind turbines and compact fluorescent lamps is causing an increase in the demand and price of REEs. The European Commission considers the REEs as the most critical raw materials group, with the highest supply risk. According to the medium-term criticality matrix of the U.S. Department of Energy (DOE), the five most critical REEs are neodymium (Nd), europium (Eu), terbium (Tb), dysprosium (Dy) and yttrium (Y). China is presently producing more than 90% of all rare earths, although they possess less than 40% of the proven reserves. Due to large and increasing domestic demands, China tightened its REE export quota from 2012 onwards. These export quotas caused serious problems for REE users outside of China. To tackle the REE supply challenge, several approaches have been proposed. Fortunately India is blessed with large resources of rare earths in the form of monazite found in the beach sands of Kerala, Tamil Nadu and Odisha. Indian Rare Earths Limited at Aluva near Kochi used to produce mainly mixed rare earths chloride and export to USA, UK, France, Japan, etc. During the 1990s and early 2000s this plant exported pure oxides of samarium, neodymium, etc. to developed countries. This national conference has expanded its canvas by including newer emerging areas in rare earths recycling, environmental issues, recent advances in rare earth material science, rare earth research and development initiatives around the world which provide a platform for the growth of rare earth Industry. Papers relevant to INIS are indexed separately

Earth Conductivity Estimation from Through-the-Earth Measurements of 94 Coal Mines Using Different Electromagnetic Models.

Science.gov (United States)

Yan, Lincan; Waynert, Joseph; Sunderman, Carl

2014-10-01

Through-the-Earth (TTE) communication systems require minimal infrastructure to operate. Hence, they are assumed to be more survivable and more conventional than other underground mine communications systems. This survivability is a major advantage for TTE systems. In 2006, Congress passed the Mine Improvement and New Emergency Response Act (MINER Act), which requires all underground coal mines to install wireless communications systems. The intent behind this mandate is for trapped miners to be able to communicate with surface personnel after a major accident-hence, the interest in TTE communications. To determine the likelihood of establishing a TTE communication link, it would be ideal to be able to predict the apparent conductivity of the overburden above underground mines. In this paper, all 94 mine TTE measurement data collected by Bureau of Mines in the 1970s and early 1980s, are analyzed for the first time to determine the apparent conductivity of the overburden based on three different models: a homogenous half-space model, a thin sheet model, and an attenuation factor or Q-factor model. A statistical formula is proposed to estimate the apparent earth conductivity for a specific mine based on the TTE modeling results given the mine depth and signal frequency.

Areva and sustainable development 2003 summary report

International Nuclear Information System (INIS)

2004-01-01

This document is a summary of the 2003 report on the sustainable development of the world nuclear industry leader, Areva. The 2002 report helped establish the status of Areva entities sustainable development performance and identity areas for improvement. The 2003 report presents the continuous improvement process, including accomplishments and projects initiated as well as difficulties encountered and ground yet to be covered. Two new tools support this process. The Areva Way self assessment model allows each unit to assess its own performance against the sustainable development commitments and the Areva values charter lays down ethical principles of action and rules of conduct. Over the coming months, the Group will devote considerable effort to extending the sustainable development initiative to the activities resulting from the acquisition of Alstom Transmission and Distribution operations in early 2004. (A.L.B.)

GMES Initial Operations - Network for Earth Observation Research Training (GIONET)

Science.gov (United States)

Nicolas-Perea, V.; Balzter, H.

2012-12-01

GMES Initial Operations - Network for Earth Observation Research Training (GIONET) is a Marie Curie funded project that aims to establish the first of a kind European Centre of Excellence for Earth Observation Research Training. GIONET is a partnership of leading Universities, research institutes and private companies from across Europe aiming to cultivate a community of early stage researchers in the areas of optical and radar remote sensing skilled for the emerging GMES land monitoring services during the GMES Initial Operations period (2011-2013) and beyond. GIONET is expected to satisfy the demand for highly skilled researchers and provide personnel for operational phase of the GMES and monitoring and emergency services. It will achieve this by: -Providing postgraduate training in Earth Observation Science that exposes students to different research disciplines and complementary skills, providing work experiences in the private and academic sectors, and leading to a recognized qualification (Doctorate). -Enabling access to first class training in both fundamental and applied research skills to early-stage researchers at world-class academic centers and market leaders in the private sector. -Building on the experience from previous GMES research and development projects in the land monitoring and emergency information services. The training program through supervised research focuses on 14 research topics (each carried out by an Early Stage Researchers based in one of the partner organization) divided in 5 main areas: Forest monitoring: Global biomass information systems Forest Monitoring of the Congo Basin using Synthetic Aperture radar (SAR) Multi-concept Earth Observation Capabilities for Biomass Mapping and Change Detection: Synergy of Multi-temporal and Multi-frequency Interferometric Radar and Optical Satellite Data Land cover and change: Multi-scale Remote Sensing Synergy for Land Process Studies: from field Spectrometry to Airborne Hyperspectral and

The Indian Ocean disaster: Tsunami physics and early warning dilemmas

Science.gov (United States)

Lomnitz, Cinna; Nilsen-Hofseth, Sara

Understanding the physics of tsunamis may save lives, especially near the epicenter of a large earthquake where the danger is highest and early warning is least likely to be effective.Normal modes of Earth are standing waves of the Love (toroidal) or the Rayleigh (spheroidal) variety. The Indian Ocean tsunami may have been partly or wholly caused by low-order spheroidal modes of the Earth such as 0S2, 0S3, and 0S4, that may have excited a waveguide—a layer that confines and guides a propagating wave—in the ocean.

Rare earths and rare earth alloys electrolytic preparation process and device for this process

International Nuclear Information System (INIS)

Seon, F.; Barthole, G.

1986-01-01

Electrolysis of a molten salt of rare earth or rare earth alloy for preparation of the metal or alloy is described. The molten salt bath comprises at least a rare earth chloride, at least an alkaline or alkaline earth chloride and at least an alkaline or alkaline earth fluoride [fr

CO2 Data Distribution and Support from the Goddard Earth Science Data and Information Services Center (GES-DISC)

Science.gov (United States)

Hearty, Thomas; Savtchenko, Andrey; Vollmer, Bruce; Albayrak, Arif; Theobald, Mike; Esfandiari, Ed; Wei, Jennifer

2015-01-01

This talk will describe the support and distribution of CO2 data products from OCO-2, AIRS, and ACOS, that are archived and distributed from the Goddard Earth Sciences Data and Information Services Center. We will provide a brief summary of the current online archive and distribution metrics for the OCO-2 Level 1 products and plans for the Level 2 products. We will also describe collaborative data sets and services (e.g., matchups with other sensors) and solicit feedback for potential future services.

Case report physiotherapy care of a patient diagnosed with polyarthritis with early rheumatoid arthritis

OpenAIRE

Michálková, Kateřina

2013-01-01

Title of bachelor's thesis: Case report physiotherapy care of a patient diagnosed with polyarthritis with early rheumatoid arthritis. Summary: The bachelor thesis deals with polyarthritis disease with early rheumatoid arthritis and its physiotherapy care. It consists of two parts. The general part contains a general joint anatomy, deals with the major problems of disease and polyarthritis rheumatoid arthritis, its diagnosis, treatment and physiotherapy care. Special part includes a case repor...

Survey Summary

Data.gov (United States)

U.S. Department of Health & Human Services — Nursing home summary information for the Health and Fire Safety Inspections currently listed on Nursing Home Compare, including dates of the three most recent...

Summary of the activities of the ISAM Confidence Building Working Group

International Nuclear Information System (INIS)

Dolinar, G.M.; Batandjieva, B.

2002-01-01

During the early stages of the ISAM project confidence building was a relatively new topic in the radioactive waste disposal literature, but it was beginning to receive some attention. Although almost all safety assessment activities are intended to provide a level of confidence in the results of the assessment, considering the activities from the viewpoint of how they contributed to the decision making of various 'audiences' was relatively new. The ISAM project included the Confidence Building Working Group (CBWG) to examine the topic of Confidence Building and this paper provides a summary of the working group findings. (author)

Mimicking the surface and prebiotic chemistry of early Earth using flow chemistry.

Science.gov (United States)

Ritson, Dougal J; Battilocchio, Claudio; Ley, Steven V; Sutherland, John D

2018-05-08

When considering life's aetiology, the first questions that must be addressed are "how?" and "where?" were ostensibly complex molecules, considered necessary for life's beginning, constructed from simpler, more abundant feedstock molecules on primitive Earth. Previously, we have used multiple clues from the prebiotic synthetic requirements of (proto)biomolecules to pinpoint a set of closely related geochemical scenarios that are suggestive of flow and semi-batch chemistries. We now wish to report a multistep, uninterrupted synthesis of a key heterocycle (2-aminooxazole) en route to activated nucleotides starting from highly plausible, prebiotic feedstock molecules under conditions which mimic this scenario. Further consideration of the scenario has uncovered additional pertinent and novel aspects of prebiotic chemistry, which greatly enhance the efficiency and plausibility of the synthesis.

Standards development status. Summary report

International Nuclear Information System (INIS)

1981-12-01

The Standards Development Status Summary Report is designed for scheduling, monitoring, and controlling the process by which Regulatory Standards, Guides, Reports, Petitions, and Environmental Statements are written. It is a summary of the current schedule plans for development of the above products

Rare gas systematics: Formation of the atmosphere, evolution and structure of the Earth's mantle

International Nuclear Information System (INIS)

Allegre, C.J.; Staudacher, T.; Sarda, P.; Paris-6 Univ., 75; Paris-7 Univ., 75

1987-01-01

To explain the rare gas content and isotopic composition measured in modern terrestrial materials we explore in this paper an Earth model based on four reservoirs: atmosphere, continental crust, upper mantle and lower mantle. This exploration employs three tools: mass balance equations, the concept of mean age of outgassing and the systematic use of all of the rare gases involving both absolute amount and isotopic composition. The results obtained are as follows: half of the Earth's mantle is 99% outgassed. Outgassing occurred in an early very intense stage within the first 50 Ma of Earth history and a slow continuous stage which continues to the present day. The mean age of the atmosphere is 4.4 Ga. Our model with four main reservoirs explains quantitatively both isotopic and chemical ratios, assuming that He migrates from the lower to the upper mantle whereas the heavy rare gases did not. Noble gas fluxes for He, Ar and Xe from different reservoirs have been estimated. The results constrain the K content in the earth to 278 ppm. Several geodynamic consequences are discussed. (orig.)

Lithium in Jack Hills zircons: Evidence for extensive weathering of Earth's earliest crust

Science.gov (United States)

Ushikubo, Takayuki; Kita, Noriko T.; Cavosie, Aaron J.; Wilde, Simon A.; Rudnick, Roberta L.; Valley, John W.

2008-08-01

In situ Li analyses of 4348 to 3362 Ma detrital zircons from the Jack Hills, Western Australia by SIMS reveal that the Li abundances (typically 10 to 60 ppm) are commonly over 10,000 times higher than in zircons crystallized from mantle-derived magmas and in mantle-derived zircon megacrysts (typically Jack Hills zircons also have fractionated lithium isotope ratios ( δ7Li = - 19 to + 13‰) about five times more variable than those recorded in primitive ocean floor basalts (2 to 8‰), but similar to continental crust and its weathering products. Values of δ7Li below - 10‰ are found in zircons that formed as early as 4300 Ma. The high Li compositions indicate that primitive magmas were not the source of Jack Hills zircons and the fractionated values of δ7Li suggest that highly weathered regolith was sampled by these early Archean magmas. These new Li data provide evidence that the parent magmas of ancient zircons from Jack Hills incorporated materials from the surface of the Earth that interacted at low temperature with liquid water. These data support the hypothesis that continental-type crust and oceans existed by 4300 Ma, within 250 million years of the formation of Earth and the low values of δ7Li suggest that weathering was extensive in the early Archean.

The "Earth Physics" Workshops Offered by the Earth Science Education Unit

Science.gov (United States)

Davies, Stephen

2012-01-01

Earth science has a part to play in broadening students' learning experience in physics. The Earth Science Education Unit presents a range of (free) workshops to teachers and trainee teachers, suggesting how Earth-based science activities, which show how we understand and use the planet we live on, can easily be slotted into normal science…

A vision for, and progress towards EarthCube

Science.gov (United States)

Jacobs, C.

2012-04-01

range of geosciences data collections and collectors, establish sustainable partnerships with other entities that collect data (e.g. other Federal and international agencies), the integrate simulations and observations, and foster symbiotic relationships with industry. Two realize this vision, NSF posted open letters to the community, had several WebEx session, established a social network website to stimulate community dialog (EarthCube.ning.com), held a Charrette with broad community participation, and is accepting expression of interests from the community for the early development efforts of all or part the EarthCube framework.

Asteroid 1997 XF11 Could Collide with Earth

Science.gov (United States)

Marsden, B. G.

1999-09-01

Early in 1998, the 2-km asteroid 1997 XF11 became of interest as a possible danger to the earth because it would clearly pass within--possibly well within--the earth's sphere of influence on 2028 Oct. 26 (IAUC 6837). Given the usual model of the solar system, the 2028 passage was entirely predictable in that there was then no possibility of collision with the earth (IAUC 6879). Nevertheless, despite this predictability, several colleagues insisted on estimating impact probabilities, with results ranging from 10(-3) to 10(-1117) ; although this latter figure by Muinonen may be technically correct, it surely invites the imagination of bizarre scenarios that would increase it. Surprisingly, despite a stated desire for ``peer review'' of pronouncements of an asteroid hazard, there was no consideration that 1997 XF11 might have posed a danger to the earth a few years after 2028. Given the 88-day arc of observations, the uncertainty in the 2028 miss distance meant that the object's revolution period, currently 1.73 years, could subsequently have been anything from 1.53 to 1.99 years. Furthermore, the essentially linear annual change of 4000 km in the minimum distance between the earth's orbit and the object's descending node would reduce this distance to zero during the late 2030s. Given the possibility of a post-2028 earth-resonant period such as 5/3, 7/4, 9/5 or 12/7 years, it was also predictable that there existed trajectories for 1997 XF11, entirely consistent with the available observations, that would yield an earth impact during this timeframe. A possible deep impact in 2040, a grazing impact in 2037 and other passages within 2 or 3 earth radii were in fact found. Although the chaos induced in 2028 renders the calculation of impact probabilities rather difficult, a simplistic argument gives a value of about 10(-5) in at least one of the relevant years (albeit at a very specific time). This is larger than the estimated annual 10(-6) impact probability for unknown

12 CFR 1805.101 - Summary.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Summary. 1805.101 Section 1805.101 Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS PROGRAM General Provisions § 1805.101 Summary. Under the Community...

Modeling of the Earth's gravity field using the New Global Earth Model (NEWGEM)

Science.gov (United States)

Kim, Yeong E.; Braswell, W. Danny

1989-01-01

Traditionally, the global gravity field was described by representations based on the spherical harmonics (SH) expansion of the geopotential. The SH expansion coefficients were determined by fitting the Earth's gravity data as measured by many different methods including the use of artificial satellites. As gravity data have accumulated with increasingly better accuracies, more of the higher order SH expansion coefficients were determined. The SH representation is useful for describing the gravity field exterior to the Earth but is theoretically invalid on the Earth's surface and in the Earth's interior. A new global Earth model (NEWGEM) (KIM, 1987 and 1988a) was recently proposed to provide a unified description of the Earth's gravity field inside, on, and outside the Earth's surface using the Earth's mass density profile as deduced from seismic studies, elevation and bathymetric information, and local and global gravity data. Using NEWGEM, it is possible to determine the constraints on the mass distribution of the Earth imposed by gravity, topography, and seismic data. NEWGEM is useful in investigating a variety of geophysical phenomena. It is currently being utilized to develop a geophysical interpretation of Kaula's rule. The zeroth order NEWGEM is being used to numerically integrate spherical harmonic expansion coefficients and simultaneously determine the contribution of each layer in the model to a given coefficient. The numerically determined SH expansion coefficients are also being used to test the validity of SH expansions at the surface of the Earth by comparing the resulting SH expansion gravity model with exact calculations of the gravity at the Earth's surface.

AGU Student and Early Career Leadership

Science.gov (United States)

Dolan, A. M.; Tamalavage, A.; Crumsey, J.; Klima, K.; Lechner, H. N.; LLera, K.; Oaida, C.; Okoro, M. H.; Riker, J.; van Emmerik, T. H. M.; Enderlein, C.

2017-12-01

The American Geophysical Union (AGU) is the largest single organization dedicated to the advancement of geophysics in order to promote discovery in Earth and space science for the benefit of humanity. AGU unites scientists across disciplines by promoting collaborative advances in Earth, atmospheric, oceanic, hydrologic, space, and planetary sciences. One critical strand of AGU is the volunteer leaders who work together with AGU staff to ensure that the voice of the AGU membership is heard in all forms of decision making within the organization. Volunteer leaders include the president and president elect of individual Section and Focus groups, and importantly Student and Early Career (S/EC) representatives from across the AGU landscape. Here, we will describe the roles of past and current AGU S/EC leaders and how these roles have evolved from the onset of student and early career scientist representation on the AGU Council. We will also discuss current plans for solidifying the relationship between S/EC leaders and other S/EC volunteers within AGU (e.g. those who sit on the executive committees of Section or Focus groups). We will describe the process for becoming an AGU S/EC leader and the roles that current S/EC leaders fulfill on the AGU Council, the Board, the Council Leadership Team, and on various committees that enable decision making and progress within AGU (e.g. the Governance Committee, the Centennial Committee, and the Ethics Committee). Including S/EC volunteers within AGU leadership ensures that the organization indeed progresses forward to achieve the vision of AGU: to galvanize a community of Earth and space scientists that collaboratively advances and communicates science and its power to ensure a sustainable future.

Conference Summary

International Nuclear Information System (INIS)

Tinkham, M.

1991-01-01

This summary will begin with short remarks, trying to recall some of the spirit of the presentations of each of the speakers during the first day, with no attempt at detail or completeness, given the need for a 20:1 compression relative to the original talk. The author hopes these idiosyncratic recollections do not infuriate the speakers too much. Since the speakers on the second day presented such interlocking topics, he simply tries to present some sort of consensus report, to which he adds some comments of his own. The two talks preceding this Summary on the final day dealt with the prospects for applications; since he had no chance to attempt to prepare a proper report on these, he says only a few words about those presentations

Beautiful Earth: Inspiring Native American students in Earth Science through Music, Art and Science

Science.gov (United States)

Casasanto, V.; Rock, J.; Hallowell, R.; Williams, K.; Angell, D.; Beautiful Earth

2011-12-01

The Beautiful Earth program, awarded by NASA's Competitive Opportunities in Education and Public Outreach for Earth and Space Science (EPOESS), is a live multi-media performance at partner science centers linked with hands-on workshops featuring Earth scientists and Native American experts. It aims to inspire, engage and educate diverse students in Earth science through an experience of viewing the Earth from space as one interconnected whole, as seen through the eyes of astronauts. The informal education program is an outgrowth of Kenji Williams' BELLA GAIA Living Atlas Experience (www.bellagaia.com) performed across the globe since 2008 and following the successful Earth Day education events in 2009 and 2010 with NASA's DLN (Digital Learning Network) http://tinyurl.com/2ckg2rh. Beautiful Earth takes a new approach to teaching, by combining live music and data visualizations, Earth Science with indigenous perspectives of the Earth, and hands-on interactive workshops. The program will utilize the emotionally inspiring multi-media show as a springboard to inspire participants to learn more about Earth systems and science. Native Earth Ways (NEW) will be the first module in a series of three "Beautiful Earth" experiences, that will launch the national tour at a presentation in October 2011 at the MOST science museum in collaboration with the Onandaga Nation School in Syracuse, New York. The NEW Module will include Native American experts to explain how they study and conserve the Earth in their own unique ways along with hands-on activities to convey the science which was seen in the show. In this first pilot run of the module, 110 K-12 students with faculty and family members of the Onandaga Nations School will take part. The goal of the program is to introduce Native American students to Earth Sciences and STEM careers, and encourage them to study these sciences and become responsible stewards of the Earth. The second workshop presented to participants will be the

Earth Observation Research for GMES Initial Operations

Science.gov (United States)

van Beijma, Sybrand; Balzter, Heiko; Nicolas-Perea, Virginia

2013-04-01

GMES Initial Operations - Network for Earth Observation Research Training (GIONET) is a Marie Curie funded project that aims to establish the first of a kind European Centre of Excellence for Earth Observation Research Training. GIONET is a partnership of leading Universities, research institutes and private companies from across Europe aiming to cultivate a community of early stage researchers in the areas of optical and radar remote sensing skilled for the emerging GMES land monitoring services during the GMES Initial Operations period (2011-2013) and beyond. GIONET is expected to satisfy the demand for highly skilled researchers and provide personnel for operational phase of the GMES and monitoring and emergency services. It will achieve this by: * Providing postgraduate training in Earth Observation Science that exposes students to different research disciplines and complementary skills, providing work experiences in the private and academic sectors, and leading to a recognized qualification (Doctorate). * Enabling access to first class training in both fundamental and applied research skills to early-stage researchers at world-class academic centres and market leaders in the private sector. * Building on the experience from previous GMES research and development projects in the land monitoring and emergency information services. * Developing a collaborative training network, through the placement of researchers for short periods in other GIONET organizations. Reliable, thorough and up-to-date environmental information is essential for understanding climate change the impacts it has on people's lives and ways to adapt to them. The GIONET researchers are being trained to understand the complex physical processes that determine how electromagnetic radiation interacts with the atmosphere and the land surface ultimately form the signal received by a satellite. In order to achieve this, the researchers have been placed in industry and universities across Europe, as

Generating Concise Natural Language Summaries.

Science.gov (United States)

McKeown, Kathleen; And Others

1995-01-01

Presents an approach to summarization that combines information from multiple facts into a single sentence using linguistic constructions. Describes two applications: one produces summaries of basketball games, and the other contains summaries of telephone network planning activity. Both summarize input data as opposed to full text. Discusses…

The Tree of Life on Earth

Science.gov (United States)

Stahl, D. A.

2002-12-01

Similar biochemistry and a common genetic code unite all life on earth and speak to a common origin. However, the nature of the "family tree," encompassing all life forms in a single genealogy, has only recently begun to be understood. It was only with the advent of molecular biology and methods for sequencing proteins and nucleic acids that ancient patterns of relationship could be discerned. The basis for establishing evolutionary relationships was found in the DNA, RNA, and proteins that determine each organism's biochemistry. Common sequence patterns in today's organisms - either in the order of amino acids in proteins or the four bases making up DNA or RNA - was recognized to derive from features of ancestral molecules preserved over evolutionary time. This approach to genealogical reconstruction, called molecular phylogeny, has led to the construction of a single "Tree of Life," and revealed that all of today's life (bacteria, protozoa, plants, animals, fungi) has emerged from three primary lines of descent. Properties of the most "deeply rooted" organisms then yield important clues about conditions on the early Earth. These analyses have also revealed that the greater part of the evolutionary diversity of our planet, represented by the microorganisms, has yet to be characterized.

Extraction of rare earths from iron-rich rare earth deposits

OpenAIRE

Bisaka, K.; Thobadi, I.C.; Pawlik, C.

2017-01-01

Rare earth metals are classified as critical metals by the United Nations, as they have found wide application in the fabrication of magnets, particularly those used in green energy technologies which mitigate global warming. Processing of ores containing rare earth elements is complex, and differs according to the nature of each ore. In the conventional process, run of mine (ROM) ores are processed in a physical separation plant to produce a concentrate from which rare earth elements are ext...

Meteorological Summaries

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multi-year summaries of one or more meteorological elements at a station or in a state. Primarily includes Form 1078, a United States Weather Bureau form designed...

Sexual Harassment and Organizational Outcomes Executive Summary

Science.gov (United States)

2011-10-01

quid pro quo type of Sexual harassment and Organizational, 4 sexual harassment (e.g., sexual coercion). This should drive organizational efforts to... Sexual Harassment and Organizational Outcomes Executive Summary Charlie L. Law DEFENSE EQUAL...Executive Summary] No. 99-11 Sexual harassment and Organizational, 2 Executive Summary Issue

The Early Astronomy Toolkit was Universal

Science.gov (United States)

Schaefer, Bradley E.

2018-01-01

From historical, anthropological, and archaeological records, we can reconstruct the general properties of the earliest astronomy for many cultures worldwide, and they all share many similar characteristics. The 'Early Astronomy Toolkit' (EAT) has the Earth being flat, and the heavens as a dome overhead populated by gods/heroes that rule Nature. The skies provided omens in a wide variety of manners, with eclipses, comets, and meteors always being evil and bad. Constellations were ubiquitous pictures of gods, heroes, animals, and everyday items; all for story telling. The calendars were all luni-solar, with no year counts and months only named by seasonal cues (including solstice observations and heliacal risings) with vague intercalation. Time of day came only from the sun's altitude/azimuth, while time at night came from star risings. Graves are oriented astronomically, and each culture has deep traditions of quartering the horizon. The most complicated astronomical tools were just a few sticks and stones. This is a higher level description and summary of the astronomy of all ancient cultures.This basic EAT was universal up until the Greeks, Mesopotamians, and Chinese broke out around 500 BC and afterwards. Outside the Eurasian milieu, with few exceptions (for example, planetary position measures in Mexico), this EAT represents astronomy for the rest of the world up until around 1600 AD. The EAT is present in these many cultures with virtually no variations or extensions. This universality must arise either from multiple independent inventions or by migration/diffusion. The probability of any culture independently inventing all 19 items in the EAT is low, but any such calculation has all the usual problems. Still, we realize that it is virtually impossible for many cultures to independently develop all 19 items in the EAT, so there must be a substantial fraction of migration of the early astronomical concepts. Further, the utter lack, as far as I know, of any

12 CFR 1806.101 - Summary.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Summary. 1806.101 Section 1806.101 Banks and Banking COMMUNITY DEVELOPMENT FINANCIAL INSTITUTIONS FUND, DEPARTMENT OF THE TREASURY BANK ENTERPRISE AWARD PROGRAM General Provisions § 1806.101 Summary. (a) Under the Bank Enterprise Award Program, the...

China's rare-earth industry

Science.gov (United States)

Tse, Pui-Kwan

2011-01-01

Introduction China's dominant position as the producer of over 95 percent of the world output of rare-earth minerals and rapid increases in the consumption of rare earths owing to the emergence of new clean-energy and defense-related technologies, combined with China's decisions to restrict exports of rare earths, have resulted in heightened concerns about the future availability of rare earths. As a result, industrial countries such as Japan, the United States, and countries of the European Union face tighter supplies and higher prices for rare earths. This paper briefly reviews China's rare-earth production, consumption, and reserves and the important policies and regulations regarding the production and trade of rare earths, including recently announced export quotas. The 15 lanthanide elements-lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (atomic numbers 57-71)-were originally known as the rare earths from their occurrence in oxides mixtures. Recently, some researchers have included two other elements-scandium and yttrium-in their discussion of rare earths. Yttrium (atomic number 39), which lies above lanthanum in transition group III of the periodic table and has a similar 3+ ion with a noble gas core, has both atomic and ionic radii similar in size to those of terbium and dysprosium and is generally found in nature with lanthanides. Scandium (atomic number 21) has a smaller ionic radius than yttrium and the lanthanides, and its chemical behavior is intermediate between that of aluminum and the lanthanides. It is found in nature with the lanthanides and yttrium. Rare earths are used widely in high-technology and clean-energy products because they impart special properties of magnetism, luminescence, and strength. Rare earths are also used in weapon systems to obtain the same properties.

Early Life Crises of Habitable Planets

International Nuclear Information System (INIS)

Pierrehumbert, Raymond

2006-01-01

There are a number of crises that a potentially habitable planet must avoid or surmount if its potential is to be realized. These include the runaway greenhouse, loss of atmosphere by chemical or physical processes, and long-lasting global glaciation. In this lecture I will present research on the climate dynamics governing such processes, with particular emphasis on the lessons to be learned from the cases of Early Mars and the Neoproterozoic Snowball Earth.

Mission to Planet Earth

International Nuclear Information System (INIS)

Wilson, G.S.; Backlund, P.W.

1992-01-01

Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the earth and how it works as a system. Increased understanding of the earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment. 8 refs

Mission to Planet Earth

Science.gov (United States)

Tilford, Shelby G.; Asrar, Ghassem; Backlund, Peter W.

1994-01-01

Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the Earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic Earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the Earth and how it works as a system. Increased understanding of the Earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment.

Site environmental report summary

International Nuclear Information System (INIS)

1992-01-01

In this summary of the Fernald 1992 Site Environmental Report the authors will describe the impact of the Fernald site on man and the environment and provide results from the ongoing Environmental Monitoring Program. Also included is a summary of the data obtained from sampling conducted to determine if the site complies with DOE, US Environmental Protection Agency (USEPA), and Ohio EPA (OEPA) requirements. These requirements are set to protect both man and the environment

19 CFR 151.41 - Information on entry summary.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Information on entry summary. 151.41 Section 151... Products § 151.41 Information on entry summary. On the entry summary for petroleum or petroleum products in.... If the exact volumetric quantity cannot be determined in advance, the entry summary may be made for...

VideoSET: Video Summary Evaluation through Text

OpenAIRE

Yeung, Serena; Fathi, Alireza; Fei-Fei, Li

2014-01-01

In this paper we present VideoSET, a method for Video Summary Evaluation through Text that can evaluate how well a video summary is able to retain the semantic information contained in its original video. We observe that semantics is most easily expressed in words, and develop a text-based approach for the evaluation. Given a video summary, a text representation of the video summary is first generated, and an NLP-based metric is then used to measure its semantic distance to ground-truth text ...

EarthServer: Cross-Disciplinary Earth Science Through Data Cube Analytics

Science.gov (United States)

Baumann, P.; Rossi, A. P.

2016-12-01

The unprecedented increase of imagery, in-situ measurements, and simulation data produced by Earth (and Planetary) Science observations missions bears a rich, yet not leveraged potential for getting insights from integrating such diverse datasets and transform scientific questions into actual queries to data, formulated in a standardized way.The intercontinental EarthServer [1] initiative is demonstrating new directions for flexible, scalable Earth Science services based on innovative NoSQL technology. Researchers from Europe, the US and Australia have teamed up to rigorously implement the concept of the datacube. Such a datacube may have spatial and temporal dimensions (such as a satellite image time series) and may unite an unlimited number of scenes. Independently from whatever efficient data structuring a server network may perform internally, users (scientist, planners, decision makers) will always see just a few datacubes they can slice and dice.EarthServer has established client [2] and server technology for such spatio-temporal datacubes. The underlying scalable array engine, rasdaman [3,4], enables direct interaction, including 3-D visualization, common EO data processing, and general analytics. Services exclusively rely on the open OGC "Big Geo Data" standards suite, the Web Coverage Service (WCS). Conversely, EarthServer has shaped and advanced WCS based on the experience gained. The first phase of EarthServer has advanced scalable array database technology into 150+ TB services. Currently, Petabyte datacubes are being built for ad-hoc and cross-disciplinary querying, e.g. using climate, Earth observation and ocean data.We will present the EarthServer approach, its impact on OGC / ISO / INSPIRE standardization, and its platform technology, rasdaman.References: [1] Baumann, et al. (2015) DOI: 10.1080/17538947.2014.1003106 [2] Hogan, P., (2011) NASA World Wind, Proceedings of the 2nd International Conference on Computing for Geospatial Research

A Brief History of Meteoroid and Orbital Debris Shielding Technology for US Manned Spacecraft

Science.gov (United States)

Bjorkman, Michael D.; Hyde, James L.

2008-01-01

Meteoroid and orbital debris shielding has played an important role from the beginning of manned spaceflight. During the early 60 s, meteoroid protection drove requirements for new meteor and micrometeoroid impact science. Meteoroid protection also stimulated advances in the technology of hypervelocity impact launchers and impact damage assessment methodologies. The first phase of meteoroid shielding assessments closed in the early 70 s with the end of the Apollo program. The second phase of meteoroid protection technology began in the early 80 s when it was determined that there is a manmade Earth orbital debris belt that poses a significant risk to LEO manned spacecraft. The severity of the Earth orbital debris environment has dictated changes in Space Shuttle and ISS operations as well as driven advances in shielding technology and assessment methodologies. A timeline of shielding technology and assessment methodology advances is presented along with a summary of risk assessment results.

TECHNIQUES FOR COMBINED PROCUREMENT OF HEARTS AND KIDNEYS WITH SATISFACTORY EARLY FUNCTION OF RENAL ALLOGRAFTS

Science.gov (United States)

Shaw, Byers W.; Rosenthal, J. Thomas; Griffith, Bartley F.; Haresty, Robert L.; Broznik, Brian; Hakala, Thomas; Bahnson, Henry T.; Starzl, Thomas E.

2009-01-01

SUMMARY Methods for combination of donor nephrectomy with donor cardiectomy are outlined. The satisfactory early function of 29 of 34 transplanted kidneys harvested with these techniques supports their wider application and should encourage their wider acceptance. PMID:6351307

Effects of rare earth elements La and Yb on the morphological and functional development of zebrafish embryos

Institute of Scientific and Technical Information of China (English)

Jun'an Cui; Zhiyong Zhang; Wei Bai; Ligang Zhang; Xiao He; Yuhui Ma; Yan Liu; Zhifang Chai

2012-01-01

In recent years,with the wide applications and mineral exploitation of rare earth elements,their potential environmental and health effects have caused increasing public concern.Effect of rare earth elements La and Yb on the morphological and functional development of zebrafish embryos were studied.The embryos were exposed to La3+ or Yb3+ at 0,0.01,0.1,0.3,0.5 and 1.0 mmol/L,respectively.Early life stage parameters such as egg and embryo mortality,gastrula development,tail detachment,eyes,somite formation,circulatory system,pigmentation,malformations,hatching rate,length of larvae and mortality were investigated.The results showed La3+ and Yb3+ delayed zebrafish embryo and larval development,decreased survival and hatching rates,and caused tail malformation in a concentration-dependent way.Moreover,heavy rare-earth ytterbium led to more severe acute toxicity of zebrafish embryo than light rare-earth lanthanum.

Earth Science and Public Health: Proceedings of the Second National Conference on USGS Health-Related Research

Science.gov (United States)

Buxton, Herbert T.; Griffin, Dale W.; Pierce, Brenda S.

2007-01-01

health scientists and earth scientists can lead to improved solutions for existing and emerging environmental health problems. This report summarizes the presentations and discussions held at the Second National Conference on USGS Health-Related Research, held at the USGS national headquarters in Reston, Virginia. The report presents 68 abstracts of technical presentations made at the conference and summaries of six topical breakout sessions. The abstracts cover a broad range of issues and demonstrate connections between human health and the quality and condition of our environment and wildlife. The summaries of the topical breakout sessions present ideas for advancing interdisciplinary science in areas of earth science and human health.

The Early History of Life

Science.gov (United States)

Nisbet, E. G.; Fowler, C. M. R.

2003-12-01

The youth of the Earth is strange to us. Many of the most fundamental constraints on life may have been different, especially the oxidation state of the surface. Should we suddenly land on its Hadean or early Archean surface by some sci-fi accident, we would not recognize our home. Above, the sky may have been green or some other unworldly color, and above that the weak young Sun might have been unrecognizable to someone trying to identify it from its spectrum. Below, seismology would show a hot, comparatively low-viscosity interior, possibly with a magma ocean in the deeper part of the upper mantle (Drake and Righter, 2002; Nisbet and Walker, 1982), and a core that, though present, was perhaps rather smaller than today. The continents may have been small islands in an icy sea, mostly frozen with some leads of open water, ( Sleep et al., 2001). Into these icy oceans, huge protruding Hawaii-like volcanoes would have poured out vast far-spreading floods of komatiite lavas in immense eruptions that may have created sudden local hypercane storms to disrupt the nearby icebergs. And meteorites would rain down.Or perhaps it was not so strange, nor so violent. The child is father to the man; young Earth was mother to Old Earth. Earth had hydrogen, silicate rock below and on the surface abundant carbon, which her ancient self retains today. Moreover, Earth was oxygen-rich, as today. Today, a tiny part of the oxygen is free, as air; then the oxygen would have been in the mantle while the surface oxygen was used to handcuff the hydrogen as dihydrogen monoxide. Oxygen dihydride is dense, unlikely to fly off to space, and at the poles, rock-forming. Of all the geochemical features that make Earth unique, the initial degassing (Genesis 2 : b) and then the sustained presence of liquid water is the defining oddity of this planet. Early Earth probably also kept much of its carbon, nitrogen, and sulfur as oxide or hydride. And, after the most cataclysmic events had passed, ˜4.5 Ga

School, Earth and Imagination

Science.gov (United States)

Merlini, Anna; Grieco, Giovanni; Oneta, Cristina

2015-04-01

Geology needs to be explained and narrated to the people, focusing on the goal of making that big change of mindset that will allow individuals and the entire community to tune into the timing and the ways in which the Earth evolves. In order to achieve these important goals it is necessary to educate children from an early age so that they learn to live an environmentally friendly life. With the project "School, Earth and imagination" we introduce, with a fun and new way, notions and topics in geological and environmental sciences in schools at all levels with the final goal of improving both knowledge and sensibility for these topics into the community. Through this project we start from the children (kindergarten and primary school, ages between 3 and 8 years) because they are the foundation of our society, and without foundations nothing can be built. The "School, Earth and imagination" project wants to give the children a real opportunity to approach reality and in general the surrounding environment, for the first time even before the traditional scholastic experience, with a scientific point of view, experimenting some basic physical concepts like temperature, weight, hardness and so on directly through their body. The project is structured and developed in modules that provide a high flexibility in order to meet needs and requirements of different schools in different situations. Each module is part of the journey of Mariolino, a character that represents a very curious child who introduces basic concepts associating them to geological processes. The Journey of Mariolino, as each module, follows an insistent scheme that starts from the presentation of the problem, follows with its discussion through direct questions and ends with experimentation of the hypotheses that children have proposed to validate the solution of the problem. Each module is independent and never ends without giving children a solution and is always structured with a practical activity

41 CFR 60-2.31 - Program summary.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Program summary. 60-2.31...-AFFIRMATIVE ACTION PROGRAMS Miscellaneous § 60-2.31 Program summary. The affirmative action program must be summarized and updated annually. The program summary must be prepared in a format which will be prescribed by...

Towards Big Earth Data Analytics: The EarthServer Approach

Science.gov (United States)

Baumann, Peter

2013-04-01

Big Data in the Earth sciences, the Tera- to Exabyte archives, mostly are made up from coverage data whereby the term "coverage", according to ISO and OGC, is defined as the digital representation of some space-time varying phenomenon. Common examples include 1-D sensor timeseries, 2-D remote sensing imagery, 3D x/y/t image timeseries and x/y/z geology data, and 4-D x/y/z/t atmosphere and ocean data. Analytics on such data requires on-demand processing of sometimes significant complexity, such as getting the Fourier transform of satellite images. As network bandwidth limits prohibit transfer of such Big Data it is indispensable to devise protocols allowing clients to task flexible and fast processing on the server. The EarthServer initiative, funded by EU FP7 eInfrastructures, unites 11 partners from computer and earth sciences to establish Big Earth Data Analytics. One key ingredient is flexibility for users to ask what they want, not impeded and complicated by system internals. The EarthServer answer to this is to use high-level query languages; these have proven tremendously successful on tabular and XML data, and we extend them with a central geo data structure, multi-dimensional arrays. A second key ingredient is scalability. Without any doubt, scalability ultimately can only be achieved through parallelization. In the past, parallelizing code has been done at compile time and usually with manual intervention. The EarthServer approach is to perform a samentic-based dynamic distribution of queries fragments based on networks optimization and further criteria. The EarthServer platform is comprised by rasdaman, an Array DBMS enabling efficient storage and retrieval of any-size, any-type multi-dimensional raster data. In the project, rasdaman is being extended with several functionality and scalability features, including: support for irregular grids and general meshes; in-situ retrieval (evaluation of database queries on existing archive structures, avoiding data

Networking Skills as a Career Development Practice: Lessons from the Earth Science Women's Network (ESWN)

Science.gov (United States)

Hastings, M. G.; Kontak, R.; Holloway, T.; Marin-Spiotta, E.; Steiner, A. L.; Wiedinmyer, C.; Adams, A. S.; de Boer, A. M.; Staudt, A. C.; Fiore, A. M.

2010-12-01

Professional networking is often cited as an important component of scientific career development, yet there are few resources for early career scientists to develop and build networks. Personal networks can provide opportunities to learn about organizational culture and procedures, expectations, advancement opportunities, and best practices. They provide access to mentors and job placement opportunities, new scientific collaborations, speaker and conference invitations, increased scientific visibility, reduced isolation, and a stronger feeling of community. There is evidence in the literature that a sense of community positively affects the engagement and retention of underrepresented groups, including women, in science. Thus women scientists may particularly benefit from becoming part of a network. The Earth Science Women’s Network (ESWN) began in 2002 as an informal peer-to-peer mentoring initiative among a few recent Ph.D.s. The network has grown exponentially to include over 1000 women scientists across the globe. Surveys of our membership about ESWN report positive impacts on the careers of women in Earth sciences, particularly those in early career stages. Through ESWN, women share both professional and personal advice, establish research collaborations, communicate strategies on work/life balance, connect with women at various stages of their careers, and provide perspectives from cultures across the globe. We present lessons learned through the formal and informal activities promoted by ESWN in support of the career development of women Earth scientists.

NASA Earth Science Mission Control Center Enterprise Emerging Technology Study Study (MCC Technology Study)

Science.gov (United States)

Smith, Dan; Horan, Stephen; Royer, Don; Sullivan, Don; Moe, Karen

2015-01-01

This paper reports on the results of the study to identify technologies that could have a significant impact on Earth Science mission operations when looking out at the 5-15 year horizon (through 2025). The potential benefits of the new technologies will be discussed, as well as recommendations for early research and development, prototyping, or analysis for these technologies.

Pilot Research Summaries, 1967-1970.

Science.gov (United States)

Casey, James L.; Hayes, Larry K.

This report contains one-page summaries of a majority of the 134 research studies funded through the Oklahoma Consortium on Research Development. The research covers the whole spectrum of academic topics , from nursing to ecology to art to politics.. Brief summaries of a majority of the 37 development seminars funded through the Consortium are…

Differentiation of crusts and cores of the terrestrial planets: lessons for the early Earth

International Nuclear Information System (INIS)

Solomon, S.C.

1980-01-01

It now appears probable that all of the terrestrial planets underwent some form of global chemical differentiation to produce crusts, mantles, and cores of variable relative mass fractions. There is direct seismic evidence for a crust on the Moon, and indirect evidence for distinct crusts on Mars and Venus. Substantial portions of these crusts have been in place since the time that heavy bombardment of the inner solar system ceased approximately 4 Ga ago. There is direct evidence for a sizeable core on Mars, indirect evidence for one on Mercury, and bounds on a possible small core for the Moon. Core formation is an important heat source confined to times prior to 4 Ga ago for Mercury and the Earth, but was not closely linked to crustal formation on the Moon nor, apparently, on Mars. The tectonic and volcanic histories of the surfaces of the terrestrial planets Moon, Mars, and Mercury can be used, with simple thermal history models, to restrict the earliest chemical differentiation to be shallow (outer 200-400 km) for the first two bodies and much more extensive for Mercury. Extension of these models to an Earth-size planet leads to the prediction of a hot and vigorously convecting mantle with an easily deformable crust immediately following core formation, and of the gradual development of a lithosphere and of plates with some lateral rigidity in Late Archean-Proterzoic times. (Auth.)

Earth

CERN Document Server

Carter, Jason

2017-01-01

This curriculum-based, easy-to-follow book teaches young readers about Earth as one of the eight planets in our solar system in astronomical terms. With accessible text, it provides the fundamental information any student needs to begin their studies in astronomy, such as how Earth spins and revolves around the Sun, why it's uniquely suitable for life, its physical features, atmosphere, biosphere, moon, its past, future, and more. To enhance the learning experience, many of the images come directly from NASA. This straightforward title offers the fundamental information any student needs to sp

Environmental oxygen conditions during the origin and early evolution of life

Science.gov (United States)

Towe, Kenneth M.

The well-known sensitivity of proteins and nucleic acids to UV-radiation requires that some internally consistent protection scenario be envisioned for the origin and early evolution of life on Earth. Although a variety of ozone-surrogates has been proposed, the available biochemical, geochemical and geological evidence best supports the conclusion that free oxygen was available at levels capable of providing at least a moderate ozone screen. Levels of oxygen near 1-2% of the present atmospheric level are consistent with such a screen, and with: (1) the biochemical needs of early procaryotes considered phylogenetically more primitive than the oxygen-producing Cyanobacteria; (2) the rare-earth element data from the oxide facies of the 3.8 Byr-old Isua banded-iron formations; (3) the nature and phylogenetic distribution of superoxide dismutases; (4) the need for aerobic recycling of early photosynthetic productivity dictated by the distribution of ancient sedimentary iron and organic carbon; (5) the incompatibility of dissolved reduced sulfur (to support anoxygenic photosynthesis) and ferrous iron (to support banded iron-formations) in the surface waters of the world oceans; and (6) the comparative oxygen and UV-sensitivities of modern procaryotes.

Understanding the Deep Earth: Slabs, Drips, Plumes and More - An On the Cutting Edge Workshop

Science.gov (United States)

Williams, M. L.; Mogk, D. W.; McDaris, J. R.

2010-12-01

research results to facilitate teaching about the deep earth across the geoscience curriculum. Another goal of the workshop was to experiment with, and evaluate the effectiveness of, the virtual format. Although there are advantages to face-to-face workshops, the virtual format was remarkably effective. The interactive discussions during synchronous presentations were vibrant, and the virtual format allowed participants to introduce references, images and ideas in real-time. The virtual nature of the workshop allowed participation by those who are not able to attend a traditional workshop, with an added benefit that participants had direct access to all their research and teaching materials to share with the workshop. Some participants broadcast the workshop ‘live’ to their classes and many brought discussions directly from the presentation to the classroom. The workshop webpage includes the workshop program with links to recordings of all presentations, discussion summaries, a collection of recommended resources about deep Earth research, and collections of peer-reviewed instructional activities. http://serc.carleton.edu/NAGTWorkshops/deepearth/index.html

Defining the Application Readiness of Products when Developing Earth Observing Remote Sensing Data Products

Science.gov (United States)

Escobar, V. M.

2017-12-01

Satellite remote sensing technology has contributed to the transformation of multiple earth science domains, putting space observations at the forefront of innovation in Earth Science. With new satellite missions being launched every year, new types of Earth Science data are being incorporated into science models and decision-making systems in a broad array of organizations. These applications help hazard mitigation and decision-making in government, private, and civic institutions working to reduce its impact on human wellbeing. Policy guidance and knowledge of product maturity can influence mission design as well as development of product applications in user organizations. Ensuring that satellite missions serve both the scientific and user communities without becoming unfocused and overly expensive is a critical outcome from engagement of user communities. Tracking the applications and product maturity help improve the use of data. NASA's Applications Readiness Levels reduce cost and increase the confidence in applications. ARLs help identify areas where NASA products are most useful while allowing the user to leverage products in early development as well as those ready for operational uses. By considering the needs of the user community early on in the mission-design process, agencies can use ARLs to ensure that satellites meet the needs of multiple constituencies and the development of products are integrated into user organizations organically. ARLs and user integration provide a perspective on the maturity and readiness of a products ability to influence policy and decision-making. This paper describes the mission application development process at NASA and within the Earth Science Directorate. We present the successes and challenges faced by NASA data users and explain how ARLs helps link NASA science to the appropriate policies and decision frameworks. The methods presented here can be adapted to other programs and institutions seeking to rapidly move

Influence of slip-surface geometry on earth-flow deformation, Montaguto earth flow, southern Italy

Science.gov (United States)

Guerriero, L.; Coe, Jeffrey A.; Revellio, P.; Grelle, G.; Pinto, F.; Guadagno, F.

2016-01-01

We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow.

Assessing Costs and Benefits of Early Childhood Intervention Programs. Overview and Application to the Starting Early Starting Smart Program. Executive Summary

National Research Council Canada - National Science Library

Karoly, Lynn

2001-01-01

Agency and program administrators and decisionmakers responsible for implementing early childhood intervention programs are becoming more interested in quantifying the costs and benefits of such programs...

Advanced Fusion Concepts project summaries. FY 1983

International Nuclear Information System (INIS)

1983-06-01

This report contains descriptions of the activities of all the projects supported by the Advanced Fusion Concepts Branch of the Office of Fusion Energy, US Department of Energy. These descriptions are project summaries of each of the individual projects, and contain the following: title, principle investigators, funding levels, purpose, approach, progress, plans, milestones, graduate studients, graduates, other professional staff, and recent publications. The individual project summaries are prepared by the principle investigators in collaboration with the Advanced Fusion Concepts (AFC) Branch. In addition to the project summaries, statements of branch objectives, and budget summaries are also provided

Origin and mixing timescale of Earth's late veneer

Science.gov (United States)

Prescher, C.; Allu Peddinti, D.; Bell, E. A.; Bello, L.; Cernok, A.; Ghosh, N.; Tucker, J.; Wielicki, M. M.; Zahnle, K. J.

2012-12-01

Experimental studies on the partitioning behavior of highly siderophile elements (HSE) between silicate and metallic melts imply that the Earth's mantle should have been highly depleted in these elements by core formation in an early magma ocean. However, present HSE contents of the Earth's mantle are ~3 orders of magnitude higher than that expected by experiments. The apparent over-abundance of HSE has commonly been explained by the addition of meteoritic material in the "late veneer" which describes the exogenous mass addition following the moon forming impact and concluding with the late heavy bombardment at ~3.8-3.9 Ga. The strongest evidence for this theory is that the platinum group element (PGE) contents in today's mantle are present in chondritic relative abundances, as opposed to a fractionated pattern expected with metal-silicate partitioning. Archean komatiites indicate that the PGE content of the Earth's mantle increased from about half their present abundances at 3.5 Ga to their present abundances at 2.9 Ga. This secular increase in PGE content suggests a progressive mixing of the late veneer material into the Earth's mantle. However, this time scale also implies that the whole mantle was relatively well mixed by 2.9 Ga. We use a compilation of existing isotopic and trace element data in order to constrain the origin and composition of the late veneer. We use PGE abundances, W abundances and W isotopic compositions in chondritic meteorites and the primitive upper mantle to compute the amount of mass delivered during the late veneer and find the late veneer mass to be ~0.6 % the mass of the bulk silicate Earth (consistent with earlier estimates). We also use the 187Re-187Os and 190Pt-186Os systems to constrain the composition and timing of delivery of the impacting population. We model the efficiency of mantle mixing in this time frame by using 3-dimensional numerical geodynamical simulations and geochemical constraints. Initial parameters include the

PREFACE: 8th International Symposium of the Digital Earth (ISDE8)

Science.gov (United States)

2014-02-01

Proceedings of the 8th International Symposium of Digital Earth (8th ISDE) 2013 Kuching, Sarawak, Malaysia, 26th-29th August, 2013 Conference logo This proceedings consists of the peer-reviewed papers from 8th International Symposium for Digital Earth (ISDE) held in Kuching, Sarawak, Malaysia during 26th-29th August, 2013. The 8th ISDE was a successful event in the Symposium Series of the International Society of Digital Earth, that was previously held in China (1999), Canada (2001), Czech Republic (2003), Japan (2005), the United States (2007), China (2009), and Australia (2011). The 8th ISDE, with the theme 'Transforming Knowledge into Sustainable Practice' aims to enable digital earth scientists, experts and professionals related to the field of geospatial science and technology to provide a brand new opportunity to share their ideas and insights on how we share knowledge and act together globally. In addition, the ISDE symposium series has been providing a venue for researchers and industry practitioners to discuss new ideas, collaborate to solve complex solutions to various complex problems, and importantly, pave new ways in digital earth environment. This 8th ISDE included 20 technical sessions, workshops and student sessions in various areas of digital earth; ranging from digital earth vision & innovation; earth observation technologies; ICT technologies (including spatial data infrastructures); empowering the community and engaging society; applications and innovation of digital earth for environmental applications such as hazard, pollution, flood, air quality, disaster and health, biodiversity, sustainability, forestry, early warning and emergency management, national security, natural resource management and agriculture; mining, energy and resources development; transformation towards sustainable low carbon society; digital city and green cities: towards urban sustainability; and managing water environment for sustainable development. The success of the 8

Telemedicine in Space Flight - Summary of a NASA Workshop

Science.gov (United States)

Barsten, K. N.; Watkins, S. D.; Otto, C.; Baumann, D. K.

2011-01-01

The Exploration Medical Capability Element of the Human Research Program at NASA Johnson Space Center hosted the Telemedicine Workshop in January 2011 to discuss the medical operational concept for a crewed mission to a near-Earth asteroid (NEA) and to identify areas for future work and collaboration. With the increased likelihood of a medical incident on a long duration exploration mission to a near-Earth asteroid, as well as the fact that there will likely be limited medical capabilities and resources available to diagnose and treat medical conditions, it is anticipated that a more structured use of telemedicine will become highly desirable. The workshop was convened to solicit expert opinion on current telemedicine practices and on medical care in remote environments. Workshop Objectives: The workshop brought together leaders in telemedicine and remote medicine from The University of Texas Medical Branch, Henry Ford Hospital, Ontario Telemedicine Network, U.S. Army Institute of Surgical Research, University of Miami, American Telemedicine Association, Doctors Without Borders, and the Pan American Health Organization. The primary objectives of the workshop were to document the medical operations concept for a crewed mission to a NEA, to determine gaps between current capabilities and the capabilities outlined in the operations concept, to identify research required to close these gaps, and to discuss potential collaborations with external-to-NASA organizations with similar challenges. Summary of Discussions and Conclusions: The discussions held during the workshop and the conclusions reached by the workshop participants were grouped into seven categories: Crew Medical Officers, Patient Area in Spacecraft, Training, Electronic Medical Records, Intelligent Care Systems, Consultation Protocols, Prophylactic Surgical Procedures, and Data Prioritization. The key points discussed under each category will be presented.

Rare earth octacyanomolybdates(4)

International Nuclear Information System (INIS)

Zubritskaya, D.I.; Sergeeva, A.N.; Pisak, Yu.V.

1980-01-01

Optimal conditions for synthesis of rare-earth octacyanomolybdates(4) of the Ln 4 [Mo(CN) 8 ] 3 xnH 2 O composition (where Ln is a rare-earth element, other than Pr, Pm, Lu, Tb) have been worked out. The synthesis has been accomplished by neutralization with octacianomolybdic acid with rare-earth carbonates. The composition and structure of the compounds synthesized have been studied by infrared-spectroscopy. It has been established that rare-earth octacyanomolybdates(4) form three isostructural groups

Earth Science Data Analysis in the Era of Big Data

Science.gov (United States)

Kuo, K.-S.; Clune, T. L.; Ramachandran, R.

2014-01-01

. To illustrate the effects of combining a Big Data technology with an effective means of collaboration, we relate the (fictitious) experience of an early-career Earth science researcher a few years beyond the present, interlaced and contrasted with reminiscences of its recent past (i.e., the present).

Rare earths as a future resource

International Nuclear Information System (INIS)

Cornell, D.H.

1988-01-01

The fourteen rare earth or lanthanide elements have recently emerged as an important natural resource because of the rapidly growing demand in the electronic, chemical and metallurgical industries. The Symposium on rare earth elements as a future resource presented a multidisciplinary review of rare earth chemistry, geology, beneficiation, industrial applications and marketing. Papers by experts in many fields were presented on the following topics: chemical properties of the rare earth elements; the analysis of rare earth elements and minerals; beneficiation and extraction of rare earth elements; economic geochemistry and mineralogy of rare earths; present industrial uses of rare earth elements; the role of rare earth elements in high-temperature superconductors; the technical application of high-temperature superconductors; supply and demand for rare earth products - now and in the future, and the geology of rare earth deposits

Establishing a Social Media Presence and Network for the Pennsylvania Earth Science Teachers Association (PAESTA)

Science.gov (United States)

Guertin, L. A.; Merkel, C.

2011-12-01

In Spring 2011, the Pennsylvania Earth Science Teachers Association (PAESTA) became an official state chapter of the National Earth Science Teachers Association (NESTA). Established with funds from the National Science Foundation, PAESTA is focused on advancing, extending, improving, and coordinating all levels of Earth Science education in Pennsylvania. Our goal is to reach earth science educators across Pennsylvania and beyond who are not physically co-located. An early priority of this new organization was to establish a web presence (http://www.paesta.psu.edu/) and to build an online community to support PAESTA activities and members. PAESTA exists as a distributed group made up of educators across Pennsylvania. Many initial members were participants in summer Earth and space science workshops held at Penn State University, which has allowed for face-to-face connections and network building. PAESTA will hold sessions and a reception at the Pennsylvania Science Teachers Association annual conference. The work of the group also takes place virtually via the PAESTA organizational website, providing professional development opportunities and Earth Science related teaching resources and links. As PAESTA is still in the very early days of its formation, we are utilizing a variety of social media tools to disseminate information and to promote asynchronous discussions around Earth and space science topics and pedagogy. The site features discussion boards for members and non-members to post comments along a specific topic or theme. For example, each month the PAESTA site features an article from one of the National Science Teacher's Association (NSTA)'s journals and encourages teachers to discuss and apply the pedagogical approach or strategy from the article to their classroom situation. We send email blasts so that members learn about organizational news and professional development opportunities. We also leverage in-person training sessions and conference sessions

Earthing: Health Implications of Reconnecting the Human Body to the Earth's Surface Electrons

International Nuclear Information System (INIS)

Chevalier, G.; Chevalier, G.; Sinatra, S.T.; Oschman, J.L.; Sokal, K.; Sokal, P.

2012-01-01

Environmental medicine generally addresses environmental factors with a negative impact on human health. However, emerging scientific research has revealed a surprisingly positive and overlooked environmental factor on health: direct physical contact with the vast supply of electrons on the surface of the Earth. Modern lifestyle separates humans from such contact. The research suggests that this disconnect may be a major contributor to physiological dysfunction and un wellness. Reconnection with the Earth's electrons has been found to promote intriguing physiological changes and subjective reports of well-being. Earthing (or grounding) refers to the discovery of benefits including better sleep and reduced pain from walking barefoot outside or sitting, working, or sleeping indoors connected to conductive systems that transfer the Earth's electrons from the ground into the body. This paper reviews the earthing research and the potential of earthing as a simple and easily accessed global modality of significant clinical importance

Next-generation Digital Earth.

Science.gov (United States)

Goodchild, Michael F; Guo, Huadong; Annoni, Alessandro; Bian, Ling; de Bie, Kees; Campbell, Frederick; Craglia, Max; Ehlers, Manfred; van Genderen, John; Jackson, Davina; Lewis, Anthony J; Pesaresi, Martino; Remetey-Fülöpp, Gábor; Simpson, Richard; Skidmore, Andrew; Wang, Changlin; Woodgate, Peter

2012-07-10

A speech of then-Vice President Al Gore in 1998 created a vision for a Digital Earth, and played a role in stimulating the development of a first generation of virtual globes, typified by Google Earth, that achieved many but not all the elements of this vision. The technical achievements of Google Earth, and the functionality of this first generation of virtual globes, are reviewed against the Gore vision. Meanwhile, developments in technology continue, the era of "big data" has arrived, the general public is more and more engaged with technology through citizen science and crowd-sourcing, and advances have been made in our scientific understanding of the Earth system. However, although Google Earth stimulated progress in communicating the results of science, there continue to be substantial barriers in the public's access to science. All these factors prompt a reexamination of the initial vision of Digital Earth, and a discussion of the major elements that should be part of a next generation.

Computer software summaries. Numbers 325 through 423

Energy Technology Data Exchange (ETDEWEB)

1978-08-01

The National Energy Software Center (NESC) serves as the software exchange and information center for the U.S. Department of Energy and the Nuclear Regulatory Commission. These summaries describe agency-sponsored software which is at the specification stage, under development, being checked out, in use, or available at agency offices, laboratories, and contractor installations. They describe software which is not included in the NESC library due to its preliminary status or because it is believed to be of limited interest. Codes dealing with the following subjects are included: cross section and resonance integral calculations; spectrum calculations, generation of group constants, lattice and cell problems; static design studies; depletion, fuel management, cost analysis, and power plant economics; space-independent kinetics; space--time kinetics, coupled neutronics--hydrodynamics--thermodynamics; and excursion simulations; radiological safety, hazard and accident analysis; heat transfer and fluid flow; deformation and stress distribution computations, structural analysis, and engineering design studies; gamma heating and shield design; reactor systems analysis; data preparation; data management; subsidiary calculations; experimental data processing; general mathematical and computing system routines; materials; environmental and earth sciences; space sciences; electronics and engineering equipment; chemistry; particle accelerators and high-voltage machines; physics; magnetic fusion research; biology and medicine; and data. (RWR)

Computer software summaries. Numbers 325 through 423

International Nuclear Information System (INIS)

1978-08-01

The National Energy Software Center (NESC) serves as the software exchange and information center for the U.S. Department of Energy and the Nuclear Regulatory Commission. These summaries describe agency-sponsored software which is at the specification stage, under development, being checked out, in use, or available at agency offices, laboratories, and contractor installations. They describe software which is not included in the NESC library due to its preliminary status or because it is believed to be of limited interest. Codes dealing with the following subjects are included: cross section and resonance integral calculations; spectrum calculations, generation of group constants, lattice and cell problems; static design studies; depletion, fuel management, cost analysis, and power plant economics; space-independent kinetics; space--time kinetics, coupled neutronics--hydrodynamics--thermodynamics; and excursion simulations; radiological safety, hazard and accident analysis; heat transfer and fluid flow; deformation and stress distribution computations, structural analysis, and engineering design studies; gamma heating and shield design; reactor systems analysis; data preparation; data management; subsidiary calculations; experimental data processing; general mathematical and computing system routines; materials; environmental and earth sciences; space sciences; electronics and engineering equipment; chemistry; particle accelerators and high-voltage machines; physics; magnetic fusion research; biology and medicine; and data

Executive summary

NARCIS (Netherlands)

van Nimwegen, N.; van Nimwegen, N.; van der Erf, R.

2009-01-01

The Demography Monitor 2008 gives a concise overview of current demographic trends and related developments in education, the labour market and retirement for the European Union and some other countries. This executive summary highlights the major findings of the Demography Monitor 2008 and further

EarthN: A new Earth System Nitrogen Model

OpenAIRE

Johnson, Benjamin W.; Goldblatt, Colin

2018-01-01

The amount of nitrogen in the atmosphere, oceans, crust, and mantle have important ramifications for Earth's biologic and geologic history. Despite this importance, the history and cycling of nitrogen in the Earth system is poorly constrained over time. For example, various models and proxies contrastingly support atmospheric mass stasis, net outgassing, or net ingassing over time. In addition, the amount available to and processing of nitrogen by organisms is intricately linked with and prov...

Earth's variable rotation

Science.gov (United States)

Hide, Raymond; Dickey, Jean O.

1991-01-01

Recent improvements in geodetic data and practical meteorology have advanced research on fluctuations in the earth's rotation. The interpretation of these fluctuations is inextricably linked with studies of the dynamics of the earth-moon system and dynamical processes in the liquid metallic core of the earth (where the geomagnetic field originates), other parts of the earth's interior, and the hydrosphere and atmosphere. Fluctuations in the length of the day occurring on decadal time scales have implications for the topographay of the core-mantle boundary and the electrical, magnetic, ande other properties of the core and lower mantle. Investigations of more rapid fluctuations bear on meteorological studies of interannual, seasonal, and intraseasonal variations in the general circulation of the atmosphere and the response of the oceans to such variations.

Wood fuel from early thinning and plantation cleaning. An international review

International Nuclear Information System (INIS)

Puttock, D.; Richardsson, J.

1998-01-01

Activities 1.2 (Forest management) and 1.2 (Harvesting) of Task XII/IEA Bioenergy Agreement carried out an international review of wood fuel from plantation cleaning and early thinning. The participating countries were Canada, Denmark, Finland, the Netherlands, New Zealand, Sweden and the United Kingdom. The individual country reviews and an international summary are presented in this paper. Each report gives country-related background information on forestry and wood utilization, energy potential from plantation cleaning and early thinning, environmental considerations from the viewpoint of wood fuel recovery, silvicultural systems and methods, cost of wood fuel, and knowledge gaps and problems

40 CFR 25.8 - Responsiveness summaries.

Science.gov (United States)

2010-07-01

... required.) Responsiveness summaries shall be forwarded to the appropriate decision-making official and... 25.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL PUBLIC PARTICIPATION IN... part shall prepare a Responsiveness Summary at specific decision points as specified in program...

Stars come down to Earth As estrelas descem à Terra

Directory of Open Access Journals (Sweden)

Luiz Marcelo Brandão Carneiro

2009-09-01

Full Text Available Stars come down to Earth — A little known essay by Theodor W. Adorno, Stars Come Down to Earth is a study about horoscopes and superstition, written in the form of an analysis for the astrology column of the Los Angeles Times in the early 1950s. The German philosopher points out that the texts offered to the reader are an amalgam of the rational and the irrational, revealing the frankly ideological meanderings of their object. Obra não muito conhecida de Theodor W. Adorno, As estrelas descem à Terra é um estudo sobre horóscopo e superstição, originalmente dirigido à coluna de astrologia do Los Angeles Times do início dos anos 1950. O filósofo alemão, pontuando os textos oferecidos aos leitores como um mistura entre o racional e o irracional, revela os meandros do caráter francamente ideológico de seu objeto.

Digital Earth – Young generation's comprehension and ideas

International Nuclear Information System (INIS)

Bandrova, T; Konecny, M

2014-01-01

The authors are experienced in working with children and students in the field of early warning and crises management and cartography. All these topics are closely connected to Digital Earth (DE) ideas. On the basis of a questionnaire, the young generation's comprehension of DE concept is clarified. Students from different age groups (from 19 to 36) from different countries and with different social, cultural, economical and political backgrounds are asked to provide definition of DE and describe their basic ideas about meaning, methodology and applications of the concept. The questions aim to discover the young generation's comprehension of DE ideas. They partially cover the newest trends of DE development like social, cultural and environmental issues as well as the styles of new communications (Google Earth, Facebook, LinkedIn, etc.). In order to assure the future development of the DE science, it is important to take into account the young generation's expectations. Some aspects of DE development are considered in the Conclusions

MIV Project: Executive Summary

DEFF Research Database (Denmark)

Ravazzotti, Mariolina T.; Jørgensen, John Leif; Neefs, Marc

1997-01-01

Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a reference mission scenario was defined. This report gives an executive summary of the achievements and results from the project.......Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a reference mission scenario was defined. This report gives an executive summary of the achievements and results from the project....

Early-life rotavirus and norovirus infections in relation to development of atopic manifestation in infants

NARCIS (Netherlands)

Reimerink, J.; Stelma, F.; Rockx, B.; Brouwer, D.; Stobberingh, E.; van Ree, R.; Dompeling, E.; Mommers, M.; Thijs, C.; Koopmans, M.

2009-01-01

Summary Background The increase in incidence of atopic diseases (ADs) in the developed world over the past decades has been associated with reduced exposure of childhood infections. Objective To investigate the relation between early intestinal viral infections in relation to the development of

Supporting Instruction By Defining Conceptual Relevance Of Materials: Alignment Of Resources To An Earth Systems Framework

Science.gov (United States)

Menicucci, A. J.; Bean, J. R.

2017-12-01

Environmental, geological, and climatological sciences are important facets of physical science education. However, it is often difficult for educators to acquire the necessary resources to facilitate content explanations, and demonstration of the conceptual links between individual lessons. The Understanding Global Change (UGC) Project at the University of California Museum of Paleontology (UCMP) at UC Berkeley is aligning new and existing Earth systems educational resources that are high-quality, interactive and inquiry based. Learning resources are organized by the UGC framework topics (Causes of Change, How the Earth System Works, and Measurable Changes), and focus on exploring topic relationships. Resources are currently aligned with both the UGC framework and the Next Generation Science Standards (NGSS), facilitating broad utility among K-16 educators. The overarching goal of the UGC Project is to provide the necessary resources that guide the construction of coherent, interdisciplinary instructional units. These units can be reinforced through system models, providing visual learning scaffolds for assessments of student content knowledge. Utilizing the central framework of UGC alleviates the long-standing problem of creating coherent instructional units from multiple learning resources, each organized and categorized independently across multiple platforms that may not provide explicit connections among Earth science subjects UGC topic cross listing of learning modules establishes conceptual links. Each resource is linked across several Earth system components, facilitating exploration of relationships and feedbacks between processes. Cross listed topics are therefore useful for development of broad picture learning goals via targeted instructional units. We also anticipate cultivating summaries of the explicit conceptual links explored in each resource from both current teachers and content specialists. Insructional units currated and aligned under the UGC

Melting in super-earths.

Science.gov (United States)

Stixrude, Lars

2014-04-28

We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures characteristic of super-earths. We find that the efficiency of kinetic energy deposition during accretion increases with planetary mass; considering the likely role of giant impacts and core formation, we find that super-earths probably complete their accretionary phase in an entirely molten state. Considerations of thermal regulation lead us to propose model temperature profiles of super-earths that are controlled by silicate melting. We estimate melting curves of iron and rock components up to the extreme pressures characteristic of super-earth interiors based on existing experimental and ab initio results and scaling laws. We construct super-earth thermal models by solving the equations of mass conservation and hydrostatic equilibrium, together with equations of state of rock and iron components. We set the potential temperature at the core-mantle boundary and at the surface to the local silicate melting temperature. We find that ancient (∼4 Gyr) super-earths may be partially molten at the top and bottom of their mantles, and that mantle convection is sufficiently vigorous to sustain dynamo action over the whole range of super-earth masses.

Duration of liquid water habitats on early Mars

International Nuclear Information System (INIS)

Mckay, C.P.; Davis, W.L.

1991-01-01

The duration of ice-covered lakes after the initial freezing of the early Mars is presently estimated via a climate model whose critical parameter is the existence of peak seasonal temperatures above freezing, and in which the variability of insolation is included. Under conditions in which meltwater was supplied by an ice source, it is found that water habitats could have been maintained under relatively thin ice sheets for as many as 700 million years after the onset of below-freezing global temperatures. The duration of such habitats on the early Mars therefore exceeds the upper limit of the time envisioned for the emergence of aquatic life on earth. 45 refs

Klet Observatory – European Contribution to Detecting and Tracking of Near Earth Objects

Directory of Open Access Journals (Sweden)

Milos Tichy

2012-03-01

Full Text Available Near Earth Object (NEO research is an expanding field of astronomy. Is is important for solar system science and also for protecting human society from asteroid and comet hazard.  A near-Earth object (NEO can be defined as an asteroid or comet that has a possibility of making an approach to the Earth, or possibly even collide with it. The discovery rate of current NEO surveys reflects progressive improvement in a number of technical areas. An integral part of NEO discovery is astrometric follow-up fundamental for precise orbit computation and for the reasonable judging of future close encounters with the Earth including possible impact solutions. A wide international cooperation is fundamental for NEO research.  The Klet Observatory (South Bohemia, Czech Republic is aimed especially at the confirmation, early follow-up, long-arc follow-up and recovery of Near Earth Objects. It ranks among the world´s most prolific professional NEO follow-up programmes.  The first NEO follow-up programme started at Klet in 1993 using 0.57-reflector equipped with a small CCD camera. A fundamental upgrade was made in 2002 when the 1.06-m KLENOT telescope was put into regular operation. The KLENOT Telescope is the largest telescope in Europe used exclusively for observations of minor planets (asteroids and comets and full observing time is dedicated to the KLENOT team.  Equipment, technology, software, observing strategy and results of both the Klet Observatory NEO Project between 1993-2010 and the first phase of the KLENOT Project from March 2002 to September 2008 are presented. They consist of thousands of precise astrometric measurements of Near Earth Objects and also three newly discovered Near Earth Asteroids.  Klet Observatory NEO activities as well as our future plans fully reflect international strategies and cooperation in the field of NEO studies.

Remote Sensing Data Analytics for Planetary Science with PlanetServer/EarthServer

Science.gov (United States)

Rossi, Angelo Pio; Figuera, Ramiro Marco; Flahaut, Jessica; Martinot, Melissa; Misev, Dimitar; Baumann, Peter; Pham Huu, Bang; Besse, Sebastien

2016-04-01

Planetary Science datasets, beyond the change in the last two decades from physical volumes to internet-accessible archives, still face the problem of large-scale processing and analytics (e.g. Rossi et al., 2014, Gaddis and Hare, 2015). PlanetServer, the Planetary Science Data Service of the EC-funded EarthServer-2 project (#654367) tackles the planetary Big Data analytics problem with an array database approach (Baumann et al., 2014). It is developed to serve a large amount of calibrated, map-projected planetary data online, mainly through Open Geospatial Consortium (OGC) Web Coverage Processing Service (WCPS) (e.g. Rossi et al., 2014; Oosthoek et al., 2013; Cantini et al., 2014). The focus of the H2020 evolution of PlanetServer is still on complex multidimensional data, particularly hyperspectral imaging and topographic cubes and imagery. In addition to hyperspectral and topographic from Mars (Rossi et al., 2014), the use of WCPS is applied to diverse datasets on the Moon, as well as Mercury. Other Solar System Bodies are going to be progressively available. Derived parameters such as summary products and indices can be produced through WCPS queries, as well as derived imagery colour combination products, dynamically generated and accessed also through OGC Web Coverage Service (WCS). Scientific questions translated into queries can be posed to a large number of individual coverages (data products), locally, regionally or globally. The new PlanetServer system uses the the Open Source Nasa WorldWind (e.g. Hogan, 2011) virtual globe as visualisation engine, and the array database Rasdaman Community Edition as core server component. Analytical tools and client components of relevance for multiple communities and disciplines are shared across service such as the Earth Observation and Marine Data Services of EarthServer. The Planetary Science Data Service of EarthServer is accessible on http://planetserver.eu. All its code base is going to be available on GitHub, on

Project Earth Science

CERN Document Server

Holt, Geoff

2011-01-01

Project Earth Science: Astronomy, Revised 2nd Edition, involves students in activities that focus on Earth's position in our solar system. How do we measure astronomical distances? How can we look back in time as we gaze across vast distances in space? How would our planet be different without its particular atmosphere and distance to our star? What are the geometries among Earth, the Moon, and the Sun that yield lunar phases and seasons? Students explore these concepts and others in 11 teacher-tested activities.

Advanced energy projects FY 1994 research summaries

International Nuclear Information System (INIS)

1994-09-01

The Division of Advanced Energy Projects (AEP) provides support to explore the feasibility of novel, energy-related concepts that evolve from advances in basic research. These concepts are typically at an early stage of scientific definition and, therefore, are premature for consideration by applied research or technology development programs. The AEP also supports high-risk, exploratory concepts that do not readily fit into a program area but could have several applications that may span scientific disciplines or technical areas. Projects supported by the Division arise from unsolicited ideas and concepts submitted by researchers. The portfolio of projects is dynamic and reflects the broad role of the Department in supporting research and development for improving the Nation's energy outlook. FY 1994 projects include the following topical areas: novel materials for energy technology; renewable and biodegradable materials; exploring uses of new scientific discoveries; alternate pathways to energy efficiency; alternative energy sources; and innovative approaches to waste treatment and reduction. Summaries are given for 66 projects

Studies with the EC-Earth seamless Earth system prediction model

NARCIS (Netherlands)

Hazeleger, W.; Bintanja, R.

2012-01-01

EC-Earth is a new Earth System Model (ESM) based on the operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF). Climate and weather forecasting applications share a common ancestry and are build on the same physical principles. The emerging concept of

Acetylene as fast food: Implications for development of life on anoxic primordial earth and in the outer solar system

Science.gov (United States)

Oremland, R.S.; Voytek, M.A.

2008-01-01

Acetylene occurs, by photolysis of methane, in the atmospheres of jovian planets and Titan. In contrast, acetylene is only a trace component of Earth's current atmosphere. Nonetheless, a methane-rich atmosphere has been hypothesized for early Earth; this atmosphere would also have been rich in acetylene. This poses a paradox, because acetylene is a potent inhibitor of many key anaerobic microbial processes, including methanogenesis, anaerobic methane oxidation, nitrogen fixation, and hydrogen oxidation. Fermentation of acetylene was discovered 25 years ago, and Pelobacter acetylenicus was shown to grow on acetylene by virtue of acetylene hydratase, which results in the formation of acetaldehyde. Acetaldehyde subsequently dismutates to ethanol and acetate (plus some hydrogen). However, acetylene hydratase is specific for acetylene and does not react with any analogous compounds. We hypothesize that microbes with acetylene hydratase played a key role in the evolution of Earth's early biosphere by exploiting an available source of carbon from the atmosphere and in so doing formed protective niches that allowed for other microbial processes to flourish. Furthermore, the presence of acetylene in the atmosphere of a planet or planetoid could possibly represent evidence for an extraterrestrial anaerobic ecosystem. ?? Mary Ann Liebert, Inc.

Acetylene as fast food: implications for development of life on anoxic primordial Earth and in the outer solar system.

Science.gov (United States)

Oremland, Ronald S; Voytek, Mary A

2008-02-01

Acetylene occurs, by photolysis of methane, in the atmospheres of jovian planets and Titan. In contrast, acetylene is only a trace component of Earth's current atmosphere. Nonetheless, a methane-rich atmosphere has been hypothesized for early Earth; this atmosphere would also have been rich in acetylene. This poses a paradox, because acetylene is a potent inhibitor of many key anaerobic microbial processes, including methanogenesis, anaerobic methane oxidation, nitrogen fixation, and hydrogen oxidation. Fermentation of acetylene was discovered approximately 25 years ago, and Pelobacter acetylenicus was shown to grow on acetylene by virtue of acetylene hydratase, which results in the formation of acetaldehyde. Acetaldehyde subsequently dismutates to ethanol and acetate (plus some hydrogen). However, acetylene hydratase is specific for acetylene and does not react with any analogous compounds. We hypothesize that microbes with acetylene hydratase played a key role in the evolution of Earth's early biosphere by exploiting an available source of carbon from the atmosphere and in so doing formed protective niches that allowed for other microbial processes to flourish. Furthermore, the presence of acetylene in the atmosphere of a planet or planetoid could possibly represent evidence for an extraterrestrial anaerobic ecosystem.

Application of the Reggio Emilia Approach to Early Childhood Science Curriculum.

Science.gov (United States)

Stegelin, Dolores A.

2003-01-01

This article focuses on the relevance of the Reggio Emilia approach to early childhood education for science knowledge and content standards for the preK-12 student population. The article includes: (1) a summary of key concepts; (2) a description of the science curriculum standards for K-3 in the United States; and (3) an example of an in-depth…

The NASA GOLD Mission: Exploring the Interface between Earth and Space

Science.gov (United States)

Mason, T.; Costanza, B.

2017-12-01

NASA's Global-scale Observations of the Limb and Disk, or GOLD, mission will explore a little understood area close to home, but historically hard to observe: the interface between Earth and space, a dynamic area of near-Earth space that responds both to space weather above, and the lower atmosphere below. GOLD, scheduled to launch into geostationary orbit in early 2018, will collect observations with a 30-minute cadence, much higher than any mission that has come before it. This will enable GOLD to be the first mission to study the day-to-day weather of a region of space—the thermosphere and ionosphere—rather than its long-term climate. GOLD will explore the near-Earth space environment, which is home to astronauts, radio signals used to guide airplanes and ships, and satellites that provide our communications and GPS systems. GOLD's unprecedented images and data will enable research that can improve situational awareness to help protect astronauts, spacecraft, and humans on the ground. As part of the GOLD communications and outreach program, the Office of Communications & Outreach at the Laboratory for Atmospheric and Space Physics (LASP) is developing a suite of products and programs to introduce the science of the GOLD mission to a broad range of public audiences, including students, teachers, journalists, social media practitioners, and the wider planetary and Earth science communities. We plan to showcase with this poster some of the tools we are developing to achieve this goal.

Key Frame Extraction in the Summary Space.

Science.gov (United States)

Li, Xuelong; Zhao, Bin; Lu, Xiaoqiang; Xuelong Li; Bin Zhao; Xiaoqiang Lu; Lu, Xiaoqiang; Li, Xuelong; Zhao, Bin

2018-06-01

Key frame extraction is an efficient way to create the video summary which helps users obtain a quick comprehension of the video content. Generally, the key frames should be representative of the video content, meanwhile, diverse to reduce the redundancy. Based on the assumption that the video data are near a subspace of a high-dimensional space, a new approach, named as key frame extraction in the summary space, is proposed for key frame extraction in this paper. The proposed approach aims to find the representative frames of the video and filter out similar frames from the representative frame set. First of all, the video data are mapped to a high-dimensional space, named as summary space. Then, a new representation is learned for each frame by analyzing the intrinsic structure of the summary space. Specifically, the learned representation can reflect the representativeness of the frame, and is utilized to select representative frames. Next, the perceptual hash algorithm is employed to measure the similarity of representative frames. As a result, the key frame set is obtained after filtering out similar frames from the representative frame set. Finally, the video summary is constructed by assigning the key frames in temporal order. Additionally, the ground truth, created by filtering out similar frames from human-created summaries, is utilized to evaluate the quality of the video summary. Compared with several traditional approaches, the experimental results on 80 videos from two datasets indicate the superior performance of our approach.

40 CFR 35.532 - Requirements summary.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Requirements summary. 35.532 Section 35.532 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE....532 Requirements summary. (a) Applicants and recipients of Performance Partnership Grants must meet...

40 CFR 35.132 - Requirements summary.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Requirements summary. 35.132 Section 35.132 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Requirements summary. Applicants and recipients of Performance Partnership Grants must meet: (a) The...

A Tale of Two Earths: Reconciling the Lunar and Terrestrial Hadean Records

Science.gov (United States)

Boehnke, Patrick

Studying early Earth history is complicated by the fact that the rock record doesn't extend past 4 Ga and our only record for the Hadean (>4 Ga) comes to us from detrital zircons from the Jack Hills in Western Australia. The Hadean zircon record extends back to almost 4.4 Ga and has revealed that the early Earth may have had liquid water, a felsic crust, plate boundary interactions, and possibly a biosphere. On the other hand, analyses of lunar and meteoritic samples are used to argue for a hellish Hadean Earth where frequent, large impactors repeatedly destroyed the crust. Indeed, these two models stand in direct contradiction. The focus of this thesis is to examine the evidence for these two models and ultimately propose a reconciliation based on a new interpretation of the chronology of the lunar samples used to constrain the impact history into the early Earth-Moon system. In order to improve the understanding of zircon crystallization in igneous settings, we undertook experimental studies of zircon saturation which were analyzed using a novel ion imaging approach by a secondary ion mass spectrometer. This study confirmed the original model for zircon saturation, that it is a function of only temperature, melt composition, and Zr content. Indeed, the primary implication for the early Earth from this work is that zircons are much more likely to crystallize in a felsic rather than mafic magma and therefore simply the existence of Hadean zircons suggests a high likelihood for felsic Hadean magmatism. The majority of the thesis focuses on the interpretation of 40 Ar/39Ar ages of lunar and meteorite samples, specifically with regards to impact histories derived from compilations of such ages. The primary complication with lunar and meteorite 40Ar/ 39Ar ages is that the vast majority show evidence for later disturbances due to diffusive loss of 40Ar. To try and extract meaningful thermal histories from these samples, we undertook investigations of samples from Apollo

Global Climate Summaries