Late Oligocene micromammal teeth (MP28/29) from the Lower Freshwater Molasse (USM) of Chrummorge (Lägern, N-Switzerland)     

Thomas Bolliger 《Swiss Journal of Geoscience》2013,106(2):147-159

The small sandpit “Chrummorge” on the Lägern hill (N-Switzerland) was searched for small mammal fossils. Bone fragments and about 100 teeth were retrieved while screen-washing of about 300 kg of Late Oligocene river channel-sands. Sedimentology indicates a probably meandering stream type, which likely followed a more erosional environment with tropical karsts and the formation of bolus-clay and iron ore. Even though, most of the micromammal teeth were rolled due to river transport before sedimentation, it was still possible to identify teeth of biostratigraphical importance, dating this new mammal assemblage to MP28/29 (about 24.6 ± 0.2 Ma). These Late Oligocene river channel sands are the oldest molasse sediments in the Lägern area, and they are in direct contact with Late Jurassic limestone. Thus they add important information for the reconstruction of the regional geological history.  相似文献   

A data exploration framework for validation and setup of hydrological models   总被引：5，自引：5，他引：0  

Karsten Rink  Thomas Fischer  Benny Selle  Olaf Kolditz 《Environmental Earth Sciences》2013,69(2):469-477

Over the course of hydrological research projects often a large number of heterogeneous data sets are acquired from sources as diverse as boreholes, gauging stations or satellite imagery. This data then need to be integrated into models for the simulation of hydrological processes. We propose a framework for exploration of geoscientific data and visually guided preparation of such models. Data sets from a large number of sources can be imported, combined and validated to avoid potential problems due to artefacts or inconsistencies between data sets in a subsequent simulation. Boundary conditions and domain discretisations for surface and subsurface models can be created and tested regarding criteria indicating possible numerical instabilities. All data sets including simulation results can be integrated into a user-controlled 3D scene and aspects of the data can be enhanced using a number of established visualisation techniques including thresholding and user-defined transfer functions. We present the application of this framework for the preparation of a model for simulation of groundwater flow in a river catchment in southwest Germany investigated in the scope of the WESS project.  相似文献   

Assessing the relevance of subsurface processes for the simulation of evapotranspiration and soil moisture dynamics with CLM3.5: comparison with field data and crop model simulations     

Sebastian Gayler  Joachim Ingwersen  Eckart Priesack  Thomas Wöhling  Volker Wulfmeyer  Thilo Streck 《Environmental Earth Sciences》2013,69(2):415-427

  相似文献   

On the inclusion of ground-based gravity measurements to the calibration process of a global rainfall-discharge reservoir model: case of the Durzon karst system (Larzac, southern France)     

Naomi Mazzilli  Hervé Jourde  Thomas Jacob  Vincent Guinot  Nicolas Le Moigne  Marie Boucher  Konstantinos Chalikakis  Hélène Guyard  Anatoly Legtchenko 《Environmental Earth Sciences》2013,68(6):1631-1646

This work examines the relevance of the inclusion of ground-based gravity data in the calibration process of a global rainfall-discharge reservoir model. The analysis is performed for the Durzon karst system (Larzac, France). The first part of the study focuses on the hydrological interpretation of the ground-based gravity measurements. The second part of the study investigates further the information content of the gravity data with respect to water storage dynamics modelling. The gravity-derived information is found unable to either reduce equifinality of the single-objective, discharge-based model calibration process or enhance model performance through assimilation.  相似文献   

Geothermal energy systems: research perspective for domestic energy provision   总被引：1，自引：1，他引：0  

Ernst Huenges  Thomas Kohl  Olaf Kolditz  Judith Bremer  Magdalena Scheck-Wenderoth  Thomas Vienken 《Environmental Earth Sciences》2013,70(8):3927-3933

  相似文献   

Wharf embankment and strengthening program at the Port of Oakland   总被引：1，自引：0，他引：1  

Frank R. Lobedan  Thomas LaBasco  Kenny Ogunfunmi   《Soil Dynamics and Earthquake Engineering》2002,22(9-12):1125-1130

The wharf and embankment strengthening program (WESP) is a structural modification project involving approximately 12,000 linear feet of pile-supported, marginal wharf structures. WESP is necessary because the Port of Oakland plans to deepen its berths from −42′ mean lower low water (MLLW) to −52′ MLLW, in conjunction with a Federal Government-sponsored channel dredging project. Unless they are structurally reinforced prior to the dredging, the waterfront components (i.e. wharves and embankments) will be weakened by the berth deepening project. WESP is a three-phase program that establishes the existing structural and seismic capacities of waterfront components, develops designs for improvements necessary to maintain these capacities after the berth deepening, and constructs the improvements. WESP also includes consideration of seismic upgrade improvements. The Port is currently completing the first phase of the WESP program. This paper will describe the design criteria, project phasing, construction type of waterfront components, project organization, and results to date for WESP.  相似文献   

Advances in the use of observed spatial patterns of catchment hydrological response   总被引：2，自引：0，他引：2  

Rodger B Grayson  Günter Blschl  Andrew W Western  Thomas A McMahon 《Advances in water resources》2002,25(8-12)

Over the past two decades there have been repeated calls for the collection of new data for use in developing hydrological science. The last few years have begun to bear fruit from the seeds sown by these calls, through increases in the availability and utility of remote sensing data, as well as the execution of campaigns in research catchments aimed at providing new data for advancing hydrological understanding and predictive capability. In this paper we discuss some philosophical considerations related to model complexity, data availability and predictive performance, highlighting the potential of observed patterns in moving the science and practice of catchment hydrology forward. We then review advances that have arisen from recent work on spatial patterns, including in the characterisation of spatial structure and heterogeneity, and the use of patterns for developing, calibrating and testing distributed hydrological models. We illustrate progress via examples using observed patterns of snow cover, runoff occurrence and soil moisture. Methods for the comparison of patterns are presented, illustrating how they can be used to assess hydrologically important characteristics of model performance. These methods include point-to-point comparisons, spatial relationships between errors and landscape parameters, transects, and optimal local alignment. It is argued that the progress made to date augers well for future developments, but there is scope for improvements in several areas. These include better quantitative methods for pattern comparisons, better use of pattern information in data assimilation and modelling, and a call for improved archiving of data from field studies to assist in comparative studies for generalising results and developing fundamental understanding.  相似文献   

Geochemical effects of oxidation products and framboidal pyrite oxidation in acid mine drainage prediction techniques   总被引：1，自引：0，他引：1  

P. A. Weber  W. A. Stewart  W. M. Skinner  C. G. Weisener  J. E. Thomas  R. St. C. Smart   《Applied Geochemistry》2004,19(12):1953-1974

Acid mine drainage predictive testwork associated with the Australian Mineral Industries Research Association (AMIRA) P387A Project: Prediction and Kinetic Control of Acid Mine Drainage (AMD) has critically examined static acid assessment and kinetic information from acid–base accounting techniques, including net acid production potential (NAPP), net acid generation (NAG) and column leach tests. This paper compares results on two waste rock samples that were obtained from the Kaltim Prima Coal mine (KPC) containing significant quantities of fine-grained framboidal pyrite. In agreement with other research, the authors' results indicated that framboidal pyrite is more reactive than euhedral forms due to the greater specific surface area of framboidal pyrite. This is evidenced by optical microscopy of reacted samples. Importantly, the results showed that NAPP testing is biased by the rapid acid generating oxidation of framboidal pyrite prior to, and during the acid neutralisation capacity (ANC) test. This can result in negative ANC values for samples containing significant framboidal pyrite (often “corrected” to zero kg H₂SO₄/t) when significant ANC is actually present in the sample. NAG testing using H₂O₂ indicated that samples containing a significant quantity of framboidal pyrite can result in the catalytic decomposition of the H₂O₂ prior to complete oxidation of the sulfide minerals present, requiring sequential addition of H₂O₂ for completion. A benefit of the NAG test, however, is that it assesses the net acid generation capacity of the sample without bias towards acid generation as is observed using NAPP methods. The kinetic NAG test also gives information on the reaction sequence of framboidal and euhedral pyrite. Periodic (kinetic) analysis of sub-samples from column leach tests indicated rapid oxidation of the framboidal pyrite compared to the euhedral pyrite, which was correlated with the greater framboidal pyrite surface area.Calculations to determine the sulfide/sulfate acidity derived from the oxidation of framboidal pyrite prior to; and during the ANC test have been developed to provide a better indication of the actual ANC (ANC_Actual) of the sample. Paste pH values of <pH 4–5 may be one suitable trigger mechanism for the implementation of this new method. This has led to an improved NAPP estimation of total acid production. Together with NAG and column leach testing this improved methodology has resulted in accurate AMD characterisation of samples containing acidic oxidation products and framboidal pyrite.  相似文献   

Constructing motion primitive sets to summarize periodic orbit families and hyperbolic invariant manifolds in a multi-body system     

Smith  Thomas R.  Bosanac  Natasha 《Celestial Mechanics and Dynamical Astronomy》2022,134(1):1-19

Celestial Mechanics and Dynamical Astronomy - The equilibrium figure of an inviscid tidally deformed body is the starting point for the construction of many tidal theories such as Darwinian tidal...  相似文献   

Storm-damaged saline-contaminated boreholes as a means of aquifer contamination   总被引：2，自引：0，他引：2  

Carlson DA  Van Biersel TP  Milner LR 《Ground water》2008,46(1):69-79

Saline water from a storm surge can flow down storm-damaged submerged water supply wells and contaminate boreholes and surrounding aquifers. Using data from conventional purging techniques, aquifer test response analysis, chemical analysis, and regression analysis of chloride/silica (Cl/Si) ratio, equations were derived to estimate the volume of saline water intrusion into a well and a porous media aquifer, the volume of water needed to purge a well shortly following an intrusion event, and the volume of water needed after delay of several or more months, when the saline plume has expanded. Purging time required is a function of volume of water and pumping rate. The study site well is located within a shoreline community of Lake Pontchartrain, St. Tammany Parish, in southeastern Louisiana, United States, which was impacted by two hurricane storm surges and had neither been rehabilitated nor chlorinated prior to our study. Chemical analysis of water samples in fall 2005 and purging of well and aquifer in June 6, 2006, indicated saline water had intruded the well in 2005 and the well and aquifer in 2006. The volume of water needed to purge the study well was approximately 200 casing volumes, which is significantly greater than conventionally used during collection of water samples for water quality analyses.  相似文献