Morphology and geological structure of the western part of the Olympus Mons volcano on Mars from the analysis of the Mars Express HRSC imagery     

A. T. Basilevsky  G. Neukum  B. A. Ivanov  S. K. Werner  S. van Gesselt  J. W. Head  T. Denk  R. Jaumann  H. Hoffmann  E. Hauber  T. McCord 《Solar System Research》2005,39(2):85-101

The images of the western part of Olympus Mons and adjacent plains acquired by the HRSC camera onboard the Mars Express spacecraft were studied. The morphology, topography, and color of the surface were investigated. The surface age was determined by the frequencies of impact craters. The examination of the HRSC images combined with an analysis of the MOC imagery and MOLA altitude profiles have shown that the Olympus Mons edifice, at least in its western part, is composed of not only lavas but also of sedimentary and volcanic-sedimentary rocks consisting of dust, volcanic ash, and, probably, H₂O ice that precipitated from the atmosphere. These data also indicate that glaciations, traces of which are known on the western foot of Olympus Mons (Lucchitta, 1981; Milkovich and Head, 2003), probably also covered the gentle upper slopes of the mountain. It is probable that the ice is still there, protected from sublimation by a dust blanket. Confirming (or rejecting) its presence is a challenge for the scheduled radar sounding with the MARSIS instrument mounted on the Mars Express spacecraft as well.__________Translated from Astronomicheskii Vestnik, Vol. 39, No. 2, 2005, pp. 99–116.Original Russian Text Copyright © 2005 by Basilevsky, Neukum, Ivanov, Werner, S. van Gesselt, Head, Denk, Jaumann, Hoffmann, Hauber, McCord, the HRSC Co-Investigator Team.  相似文献   

Non-linear time series analysis of precipitation events using regional climate networks for Germany     

Aljoscha Rheinwalt  Niklas Boers  Norbert Marwan  Jürgen Kurths  Peter Hoffmann  Friedrich-Wilhelm Gerstengarbe  Peter Werner 《Climate Dynamics》2016,46(3-4):1065-1074

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Intra-event characteristics of extreme erosive rainfall on Mauritius     

Werner Nel  Alexia Hauptfleisch  Paul D. Sumner  Ravindra Boojhawon  Soonil D. D. V. Rughooputh  Kumar R. Dhurmea 《自然地理学》2016,37(3-4):264-275

Mauritius is a volcanic island with a raised interior where extreme rainfall events dominate rainfall erosivity. Intra-event characteristics of the 120 highest erosive events at six selected locations between 2004 and 2008 were analyzed to provide the first detailed intra-storm data for a tropical island environment. On Mauritius, spatial variation is evident in the characteristics of extreme erosive rainfall recorded at the stations, with a noticeable increase in rainfall depth, duration, kinetic energy, and erosivity of extreme events with altitude. Extreme events in the raised interior (central plateau) show high variability of peak intensity over time as well as a higher percentage of events in which the greatest intensity occurs in the latter part of the event. Intra-event distribution of rainfall in the interior of the island shows that rainfall there has a higher potential to exceed infiltration rates as well as the ability to generate high peak runoff rates and cause substantial soil loss. The study suggests that even though within-event rainfall characteristics are complex, they have implications for soil erosion risk, and that, in tropical island environments, the within-storm distribution of rainfall should be incorporated in soil-loss modeling.  相似文献   

Global variations in regolith properties on asteroid Vesta from Dawn's low‐altitude mapping orbit          下载免费PDF全文

Brett W. Denevi  Andrew W. Beck  Ecaterina I. Coman  Bradley J. Thomson  Eleonora Ammannito  David T. Blewett  Jessica M. Sunshine  Maria Cristina De Sanctis  Jian‐Yang Li  Simone Marchi  David W. Mittlefehldt  Noah E. Petro  Carol A. Raymond  Christopher T. Russell 《Meteoritics & planetary science》2016,51(12):2366-2386

We investigate the depth, variability, and history of regolith on asteroid Vesta using data from the Dawn spacecraft. High‐resolution (15–20 m pixel^?1) Framing Camera images are used to assess the presence of morphologic indicators of a shallow regolith, including the presence of blocks in crater ejecta, spur‐and‐gully–type features in crater walls, and the retention of small (<300 m) impact craters. Such features reveal that the broad, regional heterogeneities observed on Vesta in terms of albedo and surface composition extend to the physical properties of the upper ~1 km of the surface. Regions of thin regolith are found within the Rheasilvia basin and at equatorial latitudes from ~0–90°E and ~260–360°E. Craters in these areas that appear to excavate material from beneath the regolith have more diogenitic (Rheasilvia, 0–90°E) and cumulate eucrite (260–360°E) compositions. A region of especially thick regolith, where depths generally exceed 1 km, is found from ~100–240°E and corresponds to heavily cratered, low‐albedo surface with a basaltic eucrite composition enriched in carbonaceous chondrite material. The presence of a thick regolith in this area supports the idea that this is an ancient terrain that has accumulated a larger component of exogenic debris. We find evidence for the gardening of crater ejecta toward more howarditic compositions, consistent with regolith mixing being the dominant form of “weathering” on Vesta.  相似文献   

Study of a Wind Front over the Northern South China Sea Generated by the Freshening of the North-East Monsoon     

Werner Alpers  Wai Kin Wong  Knut-Frode Dagestad  Pak Wai Chan 《Boundary-Layer Meteorology》2015,157(1):125-140

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Observed changes in SAT and GDD and the climatological suitability of the Poland-Germany-Czech Republic transboundary region for wine grapes cultivation     

Maciej Kryza  Mariusz Szymanowski  Marek Błaś  Krzysztof Migała  Małgorzata Werner  Mieczysław Sobik 《Theoretical and Applied Climatology》2015,122(1-2):207-218

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On the Panday and Huyakorn surface–subsurface hydrology test case: analysis of internal flow dynamics     

Amy M. Gaukroger  Adrian D. Werner 《水文研究》2011,25(13):2085-2093

A number of previous studies using models of integrated surface‐subsurface hydrology have adopted the Panday and Huyakorn (P&H) tilted V‐catchment test case (Panday S, Huyakorn PS. 2004. A fully coupled spatially distributed model for evaluating surface/subsurface flow. Advances in Water Resources 27: 361–382) to show inter‐code comparability. The P&H test case is used to evaluate models that simulate a broad range of hydrological processes, and yet only the catchment outflow hydrograph has been presented as verification of the consistency between codes. Therefore, a more comprehensive evaluation of the surface‐subsurface hydrology of the P&H case is needed. This study explores the internal catchment functioning of the P&H case, using the popular catchment simulator MODHMS. The processes leading to streamflow generation in the model are illustrated, including separation of overland flow (OLF) and groundwater discharge to the stream. The results identify non‐physical flow processes due to the problem set‐up, and modifications to the P&H case are suggested that include changes to stream roughness and incision of the stream channel to overcome these shortcomings. A modified P&H case produced more plausible transfers between OLF and the stream, and an increased groundwater discharge to the stream (6·5% of streamflow in the modified case compared to 0·5% in the original case). Despite changes to internal flow processes, near‐identical outflow hydrographs were obtained, showing the importance of considering and comparing internal flow processes when using surface‐subsurface hydrology test cases to evaluate integrated hydrological simulators. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Groundwater level responses in temperate mountainous terrain: regime classification,and linkages to climate and streamflow     

D. M. Allen  P. H. Whitfield  A. Werner 《水文研究》2010,24(23):3392-3412

Groundwater responses in temperate mountainous terrain are assessed using groundwater, hydrometric and climatic data from southern British Columbia, Canada. Well and stream hydrographs are analysed using a series of diagnostic tools including time series plots, hysteresis plots, and cross‐correlation plots. Characterizing the seasonal timing of the response requires consideration of the hydroclimatology of the region: rainfall‐dominated (pluvial), snowmelt‐dominated (nival) or hybrid (mixture of rain and snow). The magnitude and timing of the recharge and discharge response of the groundwater system was shown to depend on the storage and permeability characteristics of the aquifer and whether the system is stream‐driven or recharge‐driven. These two dominant stream‐aquifer system types were defined based on classifying different aquifer types found in the southwest portion of the province. The classification scheme and diagnostic tools have the potential to provide a framework for evaluating the responses of wells in other mountainous regions. Using this framework, the potential consequences of future climate change may then be better understood based on the interactions between the hydrogeological and hydroclimatic settings of these aquifers. Copyright © 2010 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons. Ltd  相似文献   

Exposure of sticklebacks (Gasterosteus aculeatus) to cadmium sulfide nanoparticles: biological effects and the importance of experimental design.   总被引：1，自引：0，他引：1  

Matthew B Sanders  Marion Sebire  Joachim Sturve  Paul Christian  Ioanna Katsiadaki  Brett P Lyons  Dave Sheahan  Jason M Weeks  Stephen W Feist 《Marine environmental research》2008,66(1):161-163

Effects of nanoparticles on aquatic organisms have been little studied to date and toxicological data are urgently needed for development of regulatory frameworks for these substances. Here, we report the findings of a study exposing sticklebacks to cadmium sulfide (CdS) as bulk material and quantum dots. Fish were exposed for 21 d in a flow through test system to 5, 50 or 500 microg l(-1) CdS nanoparticles (nCdS) coated in thiol terminated methyl polyethylene glycol (MPEG), bulk CdS or MPEG at 500 microg l(-1) (nominal concentrations). With the exception of the highest nCdS exposure, measured concentrations were approximately one order of magnitude below nominal. A single fish from each group (excluding MPEG) was examined using energy dispersive X-ray analysis (EDX) to localise cadmium, however, cadmium could not be detected in whole body sections. Elevated levels of oxidized glutathione were measured in the gills of fish exposed to 50 and 500 microg l(-1) nCdS. Induction of vitellogenin synthesis was not detected in any of the treatment groups. The number of males engaged in nest-building behaviour following exposure to 500 microg l(-1) nCdS was reduced and livers of 4/6 fish in the same treatment displayed hepatocellular nuclear pleomorphism. The results are discussed emphasising the fundamental importance of experimental design and the need to understand the behaviour of nanoparticles in the aqueous phase.  相似文献   

Basement-controlled deformation of sedimentary sequences,Anadarko Shelf,Oklahoma     

Folarin Kolawole  Molly Simpson Turko  Brett M. Carpenter 《Basin Research》2020,32(6):1365-1387

Structures rooted in the crystalline basement frequently control the deformation of the host bedrock and the overlying sedimentary sequences. Here, we elucidate the structure of the c. 2-km deep Precambrian granitic basement in the Anadarko Shelf, Oklahoma, and how the propagation of basement faults deformed the sedimentary cover. Although the basin is foreland in origin, the gently dipping shelf sequences experienced transpressional deformation in the Late Palaeozoic. We analyse a 3-D seismic reflection data set and basement penetrating well data in an area of 824 km². We observe: (a) pervasive deformation of the basement by basement-bounded interconnected mafic sills, and a system of subvertical discontinuity planes (interpreted as faults) of which some penetrate the overlying sedimentary cover; (b) three large (>10 km-long) through-going faults, with relatively small (<100 m) vertical separation (Vsep) of the deformed stratigraphic surfaces; (c) upward propagation of the large faults characterized by faulted-blocks near the basement, and faulted-monoclines in the deeper sedimentary units that transition into open monoclinal flexures up-section; (d) cumulative along-fault deformation of the stratigraphy exhibits systematic trends that varies with offset accrual; (e) two styles of Vsep—Depth distribution which include a unidirectional decrease of Vsep from the basement through the cover rocks (Style-1) and a bidirectional decrease of Vsep from a deep sedimentary unit towards the basement and shallower sequences (Style-2). We find that the basement-driven propagation (Style-1) shows greater efficiency of driving the fault deformation to shallower depths compared to the intrasedimentary-driven fault nucleation and propagation (Style-2). Our study demonstrates an evolution of cumulative Vsep trends with offset accrual on the faults, and the partial inheritance of the heterogeneous intra-basement deformation by the sedimentary cover. This contribution provides important insight into the upward propagation of basement-driven faulting associated with structural inheritance in contractional sedimentary basins.  相似文献