Über die Entstehung der Planetenatmosphären     

Dr. S. J. Bauer 《Meteorology and Atmospheric Physics》1978,27(3-4):217-232

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The Near Infrared Spectrum of Miranda: Evidence of Crystalline Water Ice     

James M. Bauer  Ted L. RoushThomas R. Geballe  Karen J. MeechTobias C. Owen  William D. Vacca  John T. Rayner  Kevin T.C. Jim 《Icarus》2002,158(1):178-190

A spectrum from 1.2 to 2.5 μm of Uranus' small satellite Miranda obtained in June 1999 reveals strong water-ice signatures. It confirms the existence of a 2.0-μm water feature previously detected on Miranda and shows a strong second broad 1.5-μm water-ice absorption feature. The spectra also reveal a weak absorption band at 1.65 μm that is indicative of crystalline water ice. Reflectance models which combine the new spectra with new photometry indicate that the spectra are characteristic of a mostly water-ice surface, with a large fraction of carbonaceous or silicate contaminates, and the possible presence of ammonia hydrate, as implied by an apparent weak feature near 2.2 μm. The possible presence of other volatiles is also investigated.  相似文献   

German Expedition 1999/2000 to Gjelsvikfjella and Western Mühlig-Hofmann-Gebirge, Central Dronning Maud Land, Antarctica     

W. Bauer  J. Jacobs 《Gondwana Research》2000,3(4):557-559

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Hillslope response to knickpoint migration in the Southern Appalachians: implications for the evolution of post‐orogenic landscapes     

Sean F. Gallen  Karl W. Wegmann  Kurt L. Frankel  Stephen Hughes  Robert Q. Lewis  Nathan Lyons  Paul Paris  Kristen Ross  Jennifer B. Bauer  Anne C. Witt 《地球表面变化过程与地形》2011,36(9):1254-1267

The southern Appalachians represent a landscape characterized by locally high topographic relief, steep slopes, and frequent mass movement in the absence of significant tectonic forcing for at least the last 200 Ma. The fundamental processes responsible for landscape evolution in a post‐orogenic landscape remain enigmatic. The non‐glaciated Cullasaja River basin of south‐western North Carolina, with uniform lithology, frequent debris flows, and the availability of high‐resolution airborne lidar DEMs, is an ideal natural setting to study landscape evolution in a post‐orogenic landscape through the lens of hillslope–channel coupling. This investigation is limited to channels with upslope contributing areas >2.7 km², a conservative estimate of the transition from fluvial to debris‐flow dominated channel processes. Values of normalized hypsometry, hypsometric integral, and mean slope vs elevation are used for 14 tributary basins and the Cullasaja basin as a whole to characterize landscape evolution following upstream knickpoint migration. Results highlight the existence of a transient spatial relationship between knickpoints present along the fluvial network of the Cullasaja basin and adjacent hillslopes. Metrics of topography (relief, slope gradient) and hillslope activity (landslide frequency) exhibit significant downstream increases below the current position of major knickpoints. The transient effect of knickpoint‐driven channel incision on basin hillslopes is captured by measuring the relief, mean slope steepness, and mass movement frequency of tributary basins and comparing these results with the distance from major knickpoints along the Cullasaja River. A conceptual model of area–elevation and slope distributions is presented that may be representative of post‐orogenic landscape evolution in analogous geologic settings. Importantly, the model explains how knickpoint migration and channel–hillslope coupling is an important factor in tectonically‐inactive (i.e. post‐orogenic) orogens for the maintenance of significant relief, steep slopes, and weathering‐limited hillslopes. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

A late Holocene record of arid events from the Cuzco region,Peru     

Alex Chepstow‐Lusty  Michael R. Frogley  Brian S. Bauer  Mark. B. Bush  Alfredo Tupayachi Herrera 《第四纪科学杂志》2003,18(6):491-502

The small recently infilled lake basin of Marcacocha (13°13′S, 72°12′W, 3355 m) in the Cuzco region of Peru has a morphology and location that renders it extremely sensitive to environmental change. A record of vegetation, human impact and climatic change during the past 4200 yr has been obtained from a highly organic core taken from the centre of the basin. Sustained arid episodes that affected the Peruvian Andes may be detectable using the proxy indicator of sedge (Cyperaceae) pollen abundances. As the lake‐level was lowered during sustained drier conditions, the local catchment was colonised by Cyperaceae, whereas during lake floods, they retreated or were submerged and pollen production was correspondingly reduced. Drier episodes during prehistoric times occurred around 900 bc , 500 bc , ad 100 and ad 550, with a longer dry episode occurring from ad 900 to 1800. Evidence from the independently derived Quelccaya ice‐core record and the archaeological chronology for the Cuzco region appears to support the climatic inferences derived from the sedge data. Many of these aridity episodes appear to correspond with important cultural changes in the Cuzco region and elsewhere in the Central Andes. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Numerical investigations of shear localization in a micro‐polar hypoplastic material     

Wenxiong Huang  Erich Bauer 《国际地质力学数值与分析法杂志》2003,27(4):325-352

In this paper a micro‐polar continuum approach is proposed to model the essential properties of cohesionless granular materials like sand. The model takes into account the influence of particle rotations, the mean grain size, the void ratio, the stresses and couple stresses. The constitutive equations for the stresses and couple stresses are incrementally non‐linear and based on the concept of hypoplasticity. For plane strain problems the implementation of the model in a finite element program is described. Numerical studies of the evolution of micro‐polar effects within a granular strip under plane shearing are presented. It is shown that the location and evolution of shear localization is strongly influenced by the initial state and the micro‐polar boundary conditions. For large shearing the state quantities tend towards a stationary state for which a certain coupling between the norm of the stress deviator and the norm of the couple stress tensor can be derived. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Surface cracks—geomorphological indicators for late Quaternary halotectonic movements in Northern Germany     

Jacob Hardt  Ben Norden  Klaus Bauer  Ole Toelle  Jenny Krambach 《地球表面变化过程与地形》2021,46(14):2963-2983

Loading and unloading effects of the Scandinavian Ice Sheet triggered halotectonic movements in Northern Germany. We present newly detected geomorphological features—termed surface cracks—which indicate a relation between ice sheet-induced salt movement and surface processes. As a part of the Central European Basin System, numerous Zechstein salt structures are abundant in the North German Basin. On the basis of high-resolution digital terrain data, more than 160 surface cracks were mapped in Northern Germany, which were grouped into 30 clusters. Almost all of the surface cracks occur above the top regions of Zechstein salt structures. The surface cracks can be several kilometres long, up to more than 20 m deep and more than 100 m wide. The comparison of the shape of the salt structures and the orientation of the cracks reveals a geometric dependency, indicating that the cracks preferably occur near the crest margins of the salt structures. Furthermore, 3D seismic data from two sites show that subsurface faults originating from salt movement exist beneath the surface cracks. We interpret the cracks as surface ruptures due to ice sheet-induced halotectonic movements. The cracks occur in a variety of Quaternary sediments and landforms. This indicates that widespread halokinetic movements occurred in the region after the last (Weichselian) deglaciation and likely before the thawing of the permafrost, possibly in a time frame from c. 30–20 ka until c. 15 ka.  相似文献   

Utilization of the non-fossil fuel target and its implications in China     

Shuwei Zhang  Nico Bauer 《Climate Policy》2013,13(3):328-344

China has pledged to meet a series of political targets on energy and environmental performance, including a target of a 15% non-fossil fuel share in total energy use by 2020. Achieving this target requires expansion of non-fossil energy and restraining energy use, which has implications for achieving the 40–45% carbon intensity reduction target. The present study outlines quantitative formulas to measure the nexus between the dynamics of GDP, energy, and carbon intensity. Considering a ‘likely’ scenario of the non-fossil fuel expansion envisioned by the Chinese government and a GDP growth rate of 8% per annum, the key to accomplishing both targets is to restrain energy consumption to attain an energy elasticity to GDP of approximately 0.53. Both targets can be achieved simultaneously with the existing non-fossil expansion plan and are within the ‘normal’ range of GDP growth seen in China over the long term. This is, however, less than the value realized over the last 10 years. To comply with the non-fossil fuel target, the potentially slower expansion of nuclear power capacity must be compensated for by other non-fossil options. Otherwise, there must be a greater attempt to decouple energy demand and economic growth in order to realize a smaller energy elasticity to GDP.

Policy relevance

China has pledged to achieve a 15% non-fossil fuel share and reduce its carbon intensity by 40–45% by 2020. The key to accomplishing both targets is to restrain energy consumption and promote the development of non-fossil fuels. The achievement of these two targets by 2020 is analysed between share of non-fossil fuel, CO₂ intensity of energy and GDP, and energy elasticity in relation to GDP. This analysis can inform the governmental energy and climate policy on the scale and pace of non-fossil fuel development, and the prerequisite regarding the energy elasticity to GDP to achieve the targets. The impacts of slower expansion of nuclear power capacity on the target achievement and implied elasticity of energy to GDP are also provided, which is close to the policy choice and actions of government on energy saving and emissions reduction.  相似文献   

Fault-controlled sedimentation in a progressively opening extensional basin: the Palaeoproterozoic Vargfors basin, Skellefte mining district, Sweden     

Tobias E. Bauer  Pietari Skyttä  Rodney L. Allen  Pär Weihed 《International Journal of Earth Sciences》2013,102(2):385-400

The Vargfors basin in the central part of the Skellefte mining district is an inverted sedimentary basin within a Palaeoproterozoic (1.89 Ga) marine volcanic arc. The fault-segmented basin formed from upper-crustal extension and subsequent compression, following a period of intense sub-marine volcanism and VMS ore formation. New detailed mapping reveals variations in stratigraphy attributed to syn-extensional sedimentation, as well as provenance of conglomerate clasts associated with tectonic activity at the transition from extension to compression. The onset of fan delta to alluvial fan sedimentation associated with basin subsidence indicates that significant dip-slip displacement accommodating rapid uplift of the intrusive complex and/or subsidence of the adjacent volcano-sedimentary domain took place along a major fault zone at the southern margin of the intrusive complex. Subsidence of the Jörn intrusive complex and/or its burial by sedimentary units caused a break in erosion of the intrusion and favoured the deposition of a tonalite clast-barren conglomerate. Clast compositions of conglomerates show that the syn-extensional deposits become younger in the south-eastern parts of the basin, indicating that opening of the basin progressed from north-west to south-east. Subsequent basin inversion, associated with the accretion to the Karelian margin, involved reverse activation of the normal faults and development of related upright synclines. Progressive crustal shortening caused the formation of break-back faults accompanied by mafic volcanic activity that particularly affected the southern contact of the Jörn intrusive complex and the northern contact of the Vargfors basin.  相似文献   

Impacts of the use of the geological subsurface for energy storage: an investigation concept     

Sebastian Bauer  Christof Beyer  Frank Dethlefsen  Peter Dietrich  Rainer Duttmann  Markus Ebert  Volker Feeser  Uwe Görke  Ralf Köber  Olaf Kolditz  Wolfgang Rabbel  Tom Schanz  Dirk Schäfer  Hilke Würdemann  Andreas Dahmke 《Environmental Earth Sciences》2013,70(8):3935-3943

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