Sample return of interstellar matter (SARIM)     

Ralf Srama  Thomas Stephan  Eberhard Grün  Norbert Pailer  Anton Kearsley  Amara Graps  Rene Laufer  Pascale Ehrenfreund  Nicolas Altobelli  Kathrin Altwegg  Siegfried Auer  Jack Baggaley  Mark J. Burchell  James Carpenter  Luigi Colangeli  Francesca Esposito  Simon F. Green  Hartmut Henkel  Mihaly Horanyi  Annette Jäckel  Sascha Kempf  Neil McBride  Georg Moragas-Klostermeyer  Harald Krüger  Pasquale Palumbo  Andre Srowig  Mario Trieloff  Peter Tsou  Zoltan Sternovsky  Oliver Zeile  Hans-Peter Röser 《Experimental Astronomy》2009,23(1):303-328

The scientific community has expressed strong interest to re-fly Stardust-like missions with improved instrumentation. We propose a new mission concept, SARIM, that collects interstellar and interplanetary dust particles and returns them to Earth. SARIM is optimised for the collection and discrimination of interstellar dust grains. Improved active dust collectors on-board allow us to perform in-situ determination of individual dust impacts and their impact location. This will provide important constraints for subsequent laboratory analysis. The SARIM spacecraft will be placed at the L2 libration point of the Sun–Earth system, outside the Earth’s debris belts and inside the solar-wind charging environment. SARIM is three-axes stabilised and collects interstellar grains between July and October when the relative encounter speeds with interstellar dust grains are lowest (4 to 20 km/s). During a 3-year dust collection period several hundred interstellar and several thousand interplanetary grains will be collected by a total sensitive area of 1 m². At the end of the collection phase seven collector modules are stored and sealed in a MIRKA-type sample return capsule. SARIM will return the capsule containing the stardust to Earth to allow for an extraction and investigation of interstellar samples by latest laboratory technologies.  相似文献   

DuneXpress     

Eberhard Grün  Ralf Srama  Nicolas Altobelli  Kathrin Altwegg  James Carpenter  Luigi Colangeli  Karl-Heinz Glassmeier  Stefan Helfert  Hartmut Henkel  Mihaly Horanyi  Annette Jäckel  Sascha Kempf  Markus Landgraf  Neil McBride  Georg Moragas-Klostermeyer  Pasquale Palumbo  Han Scholten  Andre Srowig  Zoltan Sternovsky  Xavier Vo 《Experimental Astronomy》2009,23(3):981-999

The DuneXpress observatory will characterize interstellar and interplanetary dust in-situ, in order to provide crucial information not achievable with remote sensing astronomical methods. Galactic interstellar dust constitutes the solid phase of matter from which stars and planetary systems form. Interplanetary dust, from comets and asteroids, represents remnant material from bodies at different stages of early solar system evolution. Thus, studies of interstellar and interplanetary dust with DuneXpress in Earth orbit will provide a comparison between the composition of the interstellar medium and primitive planetary objects. Hence DuneXpress will provide insights into the physical conditions during planetary system formation. This comparison of interstellar and interplanetary dust addresses directly themes of highest priority in astrophysics and solar system science, which are described in ESA’s Cosmic Vision. The discoveries of interstellar dust in the outer and inner solar system during the last decade suggest an innovative approach to the characterization of cosmic dust. DuneXpress establishes the next logical step beyond NASA’s Stardust mission, with four major advancements in cosmic dust research: (1) analysis of the elemental and isotopic composition of individual interstellar grains passing through the solar system, (2) determination of the size distribution of interstellar dust at 1 AU from 10^− 14 to 10^− 9 g, (3) characterization of the interstellar dust flow through the planetary system, (4) establish the interrelation of interplanetary dust with comets and asteroids. Additionally, in supporting the dust science objectives, DuneXpress will characterize dust charging in the solar wind and in the Earth’s magnetotail. The science payload consists of two dust telescopes of a total of 0.1 m² sensitive area, three dust cameras totaling 0.4 m² sensitive area, and a nano-dust detector. The dust telescopes measure high-resolution mass spectra of both positive and negative ions released upon impact of dust particles. The dust cameras employ different detection methods and are optimized for (1) large area impact detection and trajectory analysis of submicron sized and larger dust grains, (2) the determination of physical properties, such as flux, mass, speed, and electrical charge. A nano-dust detector searches for nanometer-sized dust particles in interplanetary space. A plasma monitor supports the dust charge measurements, thereby, providing additional information on the dust particles. About 1,000 grains are expected to be recorded by this payload every year, with 20% of these grains providing elemental composition. During the mission submicron to micron-sized interstellar grains are expected to be recorded in statistically significant numbers. DuneXpress will open a new window to dusty universe that will provide unprecedented information on cosmic dust and on the objects from which it is derived.  相似文献   

Isotopic evidence (He,B, C) for deep fluid and mud mobilization from mud volcanoes in the Caucasus continental collision zone     

Achim?KopfEmail author  Annette?Deyhle  Vasili?Y.?Lavrushin  Boris?G.?Polyak  Joris?M.?Gieskes  Guram?I.?Buachidze  Klaus?Wallmann  Anton?Eisenhauer 《International Journal of Earth Sciences》2003,92(3):407-425

The Caucasian orogenic wedge formed as a consequence of the closure of the Tethyan Ocean, and numerous fields of active mud volcanoes pepper the area adjacent to the Black and Caspian Seas. Stable isotope ratios of boron, helium, and carbon have been measured for gas, fluid and sediment samples from active mud volcanoes of Taman Peninsula and Georgia to estimate the sources and mobilization depths of the fluid phase and mud. Boron concentrations in mud volcano fluids were found to be 5–35× higher than seawater. Fluid isotope ratios vary between ¹¹B=22 and 39, while isotope ratios of the smectite- and illite-rich extruded mud are considerably depleted in heavy ¹¹B (¹¹B=–8 to +7). B contents of these muds are ~8× higher than modern marine sediments. This suggests that liquefaction prior to mud volcanism was accompanied by both B enrichment and isotope fractionation, most likely at an intermediate depth mud reservoir at 2–4 km.The hydrocarbon-generating source beds to the mud volcanoes are located at 7 to >10 km depth in the folded Maikop Formation and are of proposed Oligocene–Miocene age. The most likely mechanism is re-hydration of these shales by both hydrocarbons and a geochemically mature fluid from greater depth within the orogenic wedge. Such a deep fluid source is supported by our results from gas analyses, which imply an admixture of minor amounts (less than 1%vol) of ³He (Georgia), thermogenic ¹³C in methane as well as "ultraheavy" ¹³C in CO₂ (both Taman and Georgia). The overall results attest active local flow of geochemically different fluids along deep-seated faults penetrating the two study areas in the Caucasian orogenic wedge, with the waters as well as the gases coming from below the Maikop Formation.  相似文献   

Distribution of sedimentary organic matter in Anisian carbonate series of S Poland: evidence of third-order sea-level fluctuations     

Annette E. Götz  Joachim Szulc  Susanne Feist-Burkhardt 《International Journal of Earth Sciences》2005,94(2):267-274

The stratigraphic distribution of sedimentary organic matter in Anisian carbonate series of southern Poland is studied with respect to relative sea-level fluctuations. Palynofacies patterns clearly reflect transgressive–regressive trends that are interpreted in terms of third-order cyclicity. Major flooding phases are detected by maximum abundance of marine plankton in the upper Bithynian and Pelsonian. Transgressive and highstand deposits are recognized by changes in the terrestrial input of organic particles and the relative percentages and diversity of the plankton group. The palynological data support the sequence stratigraphic interpretation based on sedimentological features and geochemical signatures. The corresponding eustatic signals of sedimentary and organic facies are discussed. The study highlights the potential of palynofacies analysis for sequence stratigraphical interpretation.  相似文献   

Regional gravity modeling in terms of spherical base functions     

Michael Schmidt  Martin Fengler  Torsten Mayer-Gürr  Annette Eicker  Jürgen Kusche  Laura Sánchez  Shin-Chan Han 《Journal of Geodesy》2007,81(1):17-38

This article provides a survey on modern methods of regional gravity field modeling on the sphere. Starting with the classical theory of spherical harmonics, we outline the transition towards space-localizing methods such as spherical splines and wavelets. Special emphasis is given to the relations among these methods, which all involve radial base functions. Moreover, we provide extensive applications of these methods and numerical results from real space-borne data of recent satellite gravity missions, namely the Challenging Minisatellite Payload (CHAMP) and the Gravity Recovery and Climate Experiment (GRACE). We also derive high-resolution gravity field models by effectively combining space-borne and surface measurements using a new weighted level-combination concept. In addition, we outline and apply a strategy for constructing spatio-temporal fields from regional data sets spanning different observation periods.  相似文献   

Tepee-shaped agglutinated microbialites: an example from a Famennian carbonate platform on the Lennard Shelf, northern Canning Basin, Western Australia   总被引：1，自引：0，他引：1  

Nancy Chow  Annette D. George† 《Sedimentology》2004,51(2):253-265

Distinctive, metre‐scale antiformal structures are well developed in a Famennian carbonate platform in the Chedda Cliffs area of the Lennard Shelf reef complexes. The structures are distinguished by chevron‐shaped crests and thickened cores and contain abundant non‐skeletal allochems (ooids/pisoids, peloids and intraclasts) of silt to pebble size and variably developed laminations and fenestrae. The internal morphology and pervasive occurrence of fenestral clotted and wavy laminated fabrics suggest that these structures are microbial mounds composed of agglutinated stromatolites and thrombolites. Microbial fabrics most probably originated through sediment trapping and binding by microbial mats with early lithification involving microbial calcification and cementation of trapped sediment. The facies and stratigraphic context of the mounds support a shallow subtidal, transitional backreef to reef‐flat setting; however, alone these mounds do not provide unequivocal environmental information. Other large antiformal structures in Famennian platforms on the Lennard Shelf, previously described as tepee structures, show morphological similarities to the Chedda Cliffs mounds, which suggests that these other structures may also be microbial mounds. The presence of microbial mounds in platform successions further highlights the importance of microbial communities in the Lennard Shelf reef complexes.  相似文献   

Dugesia lugubris undD. polychroa im Zürichsee (Turbellaria: Tricladida)     

Annette Barkhausen  Jakob E. Walter 《Aquatic Sciences - Research Across Boundaries》1979,41(1):108-112

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Light-induced conversion of refractory,high molecular weight lake water constituents   总被引：4，自引：0，他引：4  

Dr. Annette Geller 《Aquatic Sciences - Research Across Boundaries》1985,47(1):21-26

High molecular weight DOM (apparent mol wt. ≥1500) was isolated from lake water, both in summer and in winter. Sephadex G-15 gel permeation chromatography with 0.02 M phosphate buffer yielded one peak. Elution with distilled water gave rise to distinct smaller sized subfractions. It was concluded that these compounds are weakly bound subunits of the macromolecules, which are liberated on elution with distilled water. The macromolecules were not stable in the dark. Exposing them to daylight in the laboratory and to sunlight, in quartz bottles enhanced conversion. During 6 weeks' exposure to weakly photolytic conditions (daylight >300 nm), organic carbon of the high molecular bulk substances decreased by 15% (winter) and by 25% (summer), while the concentrations of the apparent low molecular weight substances increased accordingly. Such a slow but continuous transformation may reduce also the <in situ> persistence of the macromolecules gradually.  相似文献   

Climate Change,Bushfire Risk,and Environmental Values: Examining a Potential Risk Perception Threshold in Peri-Urban South Australia     

Douglas K. Bardsley  Emily Moskwa  Delene Weber  Guy M. Robinson  Nicolette Waschl  Annette M. Bardsley 《社会与自然资源》2018,31(4):424-441

Striking a balance between the management of environmental risks and values is a challenge for decision-makers. If people perceive that environmental risks are increasing they may be willing to discount local values to manage those risks, so the identification of thresholds in risk perception in relation to specific behaviors could help to avoid policy failures. The complex relationships between perceptions of climate change and bushfire risks, environmental values and support for actions to mitigate local risks are presented for peri-urban regions in South Australia. The results of a household survey (N=988) suggest that a threshold of risk perception in relation to climate change and bushfire management has not been exceeded and people are broadly supportive of balanced management interventions. A minority of people still do not perceive that climate change is increasing bushfire risk, and are supportive of risk mitigation interventions even at the expense of local biodiversity. However, a larger group believe that climate change is a driver of bushfire risk, yet are still more likely to prioritize ecological values and are unwilling to discount those values for risk mitigation. Targeted communication could assist different groups to respond to gaps in knowledge and action to facilitate effective, differentiated interventions within forested landscapes on the margins of urban areas.  相似文献   

Outcrop analogue study of Permocarboniferous geothermal sandstone reservoir formations (northern Upper Rhine Graben,Germany): impact of mineral content,depositional environment and diagenesis on petrophysical properties     

Achim Aretz  Kristian Bär  Annette E. Götz  Ingo Sass 《International Journal of Earth Sciences》2016,105(5):1431-1452

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