Basin-related effects on ground motion for earthquake scenarios in the Lower Rhine Embayment   总被引：1，自引：0，他引：1  

Michael Ewald  Heiner Igel  Klaus-Günter Hinzen  Frank Scherbaum 《Geophysical Journal International》2006,166(1):197-212

  相似文献   

An internally consistent set of thermodynamic data for twentyone CaO-Al2O3-SiO2- H2O phases by linear parametric programming     

Heiner Halbach  Niranjan D. Chatterjee 《Contributions to Mineralogy and Petrology》1984,88(1-2):14-23

The technique of linear parametric programming has been applied to derive sets of internally consistent thermodynamic data for 21 condensed phases of the quaternary system CaO-Al₂O₃-SiO₂-H₂O (CASH) (Table 4). This was achieved by simultaneously processing:

1. calorimetric data for 16 of these phases (Table 1), and
2. experimental phase equilibria reversal brackets for 27 reactions (Table 3) involving these phases.

Calculation of equilibrium P-T curves of several arbitrarily picked reactions employing the preferred set of internally consistent thermodynamic data from Table 4 shows that the input brackets are invariably satisfied by the calculations (Fig. 2a). By contrast, the same equilibria calculated on the basis of a set of thermodynamic data derived by applying statistical methods to a large body of comparable input data (Haas et al. 1981; Hemingway et al. 1982) do not necessarily agree with the experimental reversal brackets. Prediction of some experimentally investigated phase relations not included into the linear programming input database also appears to be remarkably successful. Indications are, therefore, that the thermodynamic data listed in Table 4 may be used with confidence to predict geologic phase relations in the CASH system with considerable accuracy. For such calculated phase diagrams and their petrological implications, the reader's attention is drawn to the paper by Chatterjee et al. (1984).  相似文献   

Archaean high-K granitoids produced by remelting of earlier Tonalite–Trondhjemite–Granodiorite (TTG) in the Sangmelima region of the Ntem complex of the Congo craton,southern Cameroon     

Cosmas Kongnyuy Shang  Muharrem Satir  Emmanuel Nkonguin Nsifa  Jean-Paul Liégeois  Wolfgang Siebel  Heiner Taubald 《International Journal of Earth Sciences》2007,96(5):817-841

We present a geochemical and isotopic study that, consistent with observed field relations, suggest Sangmelima late Archaean high-K granite was derived by partial melting of older Archaean TTG. The TTG formations are sodic-trondhjemitic, showing calcic and calc-alkalic trends and are metaluminous to peraluminous. High-K granites in contrast show a potassic calc-alkaline affinity that spans the calcic, calc-alkalic, alkali-calcic and alkalic compositions. The two rock groups (TTG and high-K granites) on the other hand are both ferroan and magnesian. They have a similar degree of fractionation for LREE but a different one for HREE. Nd model ages and Sr/Y ratios define Mesoarchaean and slab-mantle derived magma compositions respectively, with Nb and Ti anomalies indicating a subduction setting for the TTG. Major and trace element in addition to Sr and Nd isotopic compositions support field observations that indicate the derivation of the high-K granitic group from the partial melting of the older TTG equivalent at depth. Geochemical characteristics of the high-K granitic group are therefore inherited features from the TTG protolith and cannot be used for determining their tectonic setting. The heat budget required for TTG partial melting is ascribed to the upwelling of the mantle marked by a doleritic event of identical age as the generated high-K granite melts. The cause of this upwelling is related to linear delamination along mega-shear zones in an intracontinental setting.  相似文献   

Broad-band observations of earthquake-induced rotational ground motions     

Heiner Igel  Alain Cochard  Joachim Wassermann  Asher Flaws †  Ulrich Schreiber  Alex Velikoseltsev  Nguyen Pham Dinh 《Geophysical Journal International》2007,168(1):182-196

  相似文献   

Synoptic Hα Full-Disk Observations of the Sun from Big Bear Solar Observatory – I. Instrumentation,Image Processing,Data Products,and First Results     

Denker  C.  Johannesson  A.  Marquette  W.  Goode  P.R.  Wang  H.  Zirin  H. 《Solar physics》1999,184(1):87-102

The Big Bear Solar Observatory (BBSO) has a long tradition of synoptic full-disk observations. Synoptic observations of contrast enhanced full-disk images in the Caii K-line have been used with great success to reproduce the Hi L irradiance variability observed with the Upper Atmosphere Research Satellite (UARS). Recent improvements in data calibration procedures and image- processing techniques enable us now to provide contrast enhanced H full-disk images with a spatial resolution of approximately 2 and a temporal resolution of up to 3 frames min–1.In this first paper in a series, we describe the instruments, the data calibration procedures, and the image-processing techniques used to obtain our daily H full-disk observations. We also present the final data products such as low- and high-contrast images, and Carrington rotation charts. A time series of an erupting mini- filament further illustrates the quality of our H full-disk observations and motivate one of the future research projects. This lays a solid foundation for our subsequent studies of solar activity and chromospheric fine structures. The high quality and the sunrise- to-sunset operation of the H full-disk observations presented in this paper make them an ideal choice to study statistical properties of mini-filament eruptions, chromospheric differential rotation, and meridional flows within the chromosphere, as well as the evolution of active regions, filaments, flares, and prominences.  相似文献   

Speckle Masking Imaging of Sunspots and Pores     

Denker  Carsten 《Solar physics》1998,180(1-2):81-108

In recent years, speckle interferometry has been successfully applied to various solar phenomena and provides a powerful tool to study solar small-scale structures. The present investigation lays special emphasis on sunspots and sunspot pores. The observations have been performed with the Vacuum Tower Telescope (VTT) at the Observatorio del Teide (Tenerife) in the years from 1992 to 1994. Time series of high-spatial-resolution observations reveal the highly dynamical evolution of sunspot fine structures such as umbral dots, penumbral grains or the small-scale brightenings in the vicinity of sunspots observed in the wings of strong chromospheric absorption lines (moustache phenomenon). The reconstructed images show small-scale structures close to the telescopic diffraction limit of 0.16 at 550 nm. Furthermore, the high transmission of a Fabry–Pérot interferometer (FPI) as the principal optical element of a two-dimensional spectrometer allows one to reconstruct directly images taken within a passband of 0.014 nm.  相似文献   

Digitization of sunspot drawings by Spörer made in 1861–1894     

A. Diercke  R. Arlt  C. Denker 《Astronomische Nachrichten》2015,336(1):53-62

Most of our knowledge about the Sun's activity cycle arises from sunspot observations over the last centuries since telescopes have been used for astronomy. The German astronomer Gustav Spörer observed almost daily the Sun from 1861 until the beginning of 1894 and assembled a 33‐year collection of sunspot data covering a total of 445 solar rotation periods. These sunspot drawings were carefully placed on an equidistant grid of heliographic longitude and latitude for each rotation period, which were then copied to copper plates for a lithographic reproduction of the drawings in astronomical journals. In this article, we describe in detail the process of capturing these data as digital images, correcting for various effects of the aging print materials, and preparing the data for contemporary scientific analysis based on advanced image processing techniques. With the processed data we create a butterfly diagram aggregating sunspot areas, and we present methods to measure the size of sunspots (umbra and penumbra) and to determine tilt angles of active regions. A probability density function of the sunspot area is computed, which conforms to contemporary data after rescaling. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

How well do reanalyses represent the southern African precipitation?     

Qiong Zhang  Heiner Körnich  Karin Holmgren 《Climate Dynamics》2013,40(3-4):951-962

  相似文献   

A comparison between cokriging and ordinary kriging: Case study with a polymetallic deposit     

Guocheng Pan  Dave Gaard  Ken Moss  Tim Heiner 《Mathematical Geology》1993,25(3):377-398

Cokriging is applied to the estimation of mineral resources in a polymetallic deposit. Several major steps, which should be taken in using cokriging, are highlighted as necessary practical considerations. The case study is related to an ultramafic copper-nickel deposit. Six elements, Cu, Ni, Au, Ag, Pt, and Pd, occurring in the deposit, are partitioned into three subgroups and the elements within each group are simultaneously estimated on the basis of over 4000 drill assays. A comparison was made between ordinary kriging and cokriging methods through cross-validation. The results show that cokriging has significantly improved the estimates of resources by reducing the overall estimation error by over 15% and the variance of error by over 20%.  相似文献   

Present rate of uplift in Fennoscandia from GRACE and absolute gravimetry   总被引：2，自引：0，他引：2  

Holger Steffen  Olga Gitlein  Heiner Denker  Jürgen Müller  Ludger Timmen 《Tectonophysics》2009,474(1-2):69

Fennoscandia is a key region for studying effects of glacial isostatic adjustment. The associated mass variations can be detected by the Gravity Recovery and Climate Experiment (GRACE) satellite mission, which observes the Earth's gravity field since April 2002, as well as by absolute gravimetry field campaigns. Since 2003, annual absolute gravity (AG) measurements have been performed in Fennoscandia by the Institut für Erdmessung (IfE, Institute of Geodesy) of the Leibniz Universität Hannover, Germany, within a multi-national cooperation. This offers a unique opportunity for validation and evaluation of the GRACE results. In this preliminary study, the GRACE results are compared to secular gravity changes based on the surveys from 2004 to 2007 with the FG5-220 gravimeter of the IfE.The results from GRACE monthly solutions provided by different analysis centres show temporal gravity variations in Fennoscandia. The included secular variations are in good agreement with former studies. The uplift centre is located west of the Bothnian Bay, the whole uplift area comprises Northern Europe. Nevertheless, the differences between the GRACE solutions are larger than expected and the different centre-specific processing techniques have a very strong effect on possible interpretations of GRACE results. The comparison of GRACE to the AG measurements reveals that the determined trends fit well with results from GRACE at selected stations, especially for the solution provided by the GFZ. Variations of land hydrology clearly influence results from GRACE and the AG measurements.  相似文献