Reply to Comment by W. Kurz on “Tectonic map and overall architecture of the Alpine orogen”     

Stefan M. Schmid  Bernhard Fügenschuh  Eduard Kissling  Ralf Schuster 《Eclogae Geologicae Helvetiae》2005,98(1):99-101

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Absolute phase center corrections of satellite and receiver antennas   总被引：9，自引：2，他引：9  

Ralf Schmid  Markus Rothacher  Daniela Thaller  Peter Steigenberger 《GPS Solutions》2005,9(4):283-293

Results of the estimation of azimuth-dependent phase center variations (PCVs) of GPS satellite antennas using global GPS data are presented. Significant variations of up to ±3–4 mm that are demonstrated show excellent repeatability over eight years. The application of the azimuthal PCVs besides the nadir-dependent ones will lead to a further reduction in systematic antenna effects. In addition, the paper focuses on the benefit of a possible transition from relative to absolute PCVs. Apart from systematic changes in the global station coordinates, one can expect the GPS results to be less dependent on the elevation cut-off angle. This, together with the significant reduction of tropospheric zenith delay biases between GPS and VLBI, stands for an important step toward more consistency between different space geodetic techniques.  相似文献   

Comparisons of homogeneously reprocessed GPS and VLBI long time-series of troposphere zenith delays and gradients     

Peter Steigenberger  Volker Tesmer  Manuela Krügel  Daniela Thaller  Ralf Schmid  Sibylle Vey  Markus Rothacher 《Journal of Geodesy》2007,81(6-8):503-514

Troposphere parameters estimated from space-geodetic techniques, like the Global Positioning System (GPS) or Very Long Baseline Interferometry (VLBI), can be used to monitor the atmospheric water vapor content. Although the troposphere can only be monitored at discrete locations, the distribution of the instruments, at least the GPS antennas, can be assumed to be quasi-global. Critical in the data analysis are systematic effects within each single technique that significantly degrade the accuracy and especially the long-term stability of the zenith delay determination. In this paper, consistent time-series of troposphere zenith delays and gradients from homogeneously reprocessed GPS and VLBI solutions are compared for a time period of 11 years. The homogeneity of these completely reprocessed time-series is essential to avoid misinterpretations due to individual model changes. Co-located sites are used to investigate systematic effects and the long-term behavior of the two space-geodetic techniques. Both techniques show common signals in the troposphere parameters at a very high level of precision. The biases between the troposphere zenith delays are at the level of a few millimeters. On the other hand, long-term trends significantly differ for the two techniques, preventing climatological interpretations at present. Tests assume these differences to be due to mathematical artifacts such as different sampling rates and unmodeled semi-annual signals with varying amplitudes.  相似文献   

Multi-stage thrusting at the "Penninic Front" in the Western Alps between Mont Blanc and Pelvoux massifs     

Stefano Ceriani  Bernhard Fügenschuh  Stefan M. Schmid 《International Journal of Earth Sciences》2001,90(3):685-702

The different segments of the tectonic boundary between external (European) and internal (Penninic) units in the Western Alps, the so-called Penninic Front (PF), formed at different times and according to different kinematic scenarios. During a first episode (Eocene), the PF corresponds to a transpressive suture zone between Penninic and European units. North- to NNW-trending stretching lineations, found along internal nappe contacts within the Penninic units, are related to this episode. This subduction zone was sealed by the Priabonian flysch of the Aiguilles d'Arves, a detrital trench formation that formed during the final stages of subduction. During a second episode, starting in mid-Oligocene times, the PF, imaged along the ECORS-CROP profile, acted as a WNW-directed thrust. This thrust, the Roselend Thrust (RT), only partially coincides with the PF. South of Moûtiers, the RT propagates into the Dauphinois units, carrying the former Eocene PF (including the Priabonian flysch) passively in its hangingwall. South of the Pelvoux massif the RT finds its continuation along the "Briançonnais Front", an out-of-sequence thrust behind the Embrunais-Ubaye nappes. On a larger scale, our findings indicate oblique (sinistral) collision within the future Western Alps during the Eocene, followed by westward indentation of the Adriatic block.  相似文献   

Fission-track constraints on the thermal and tectonic evolution of the Apuseni Mountains (Romania)     

Alexandre Kounov  Stefan M. Schmid 《International Journal of Earth Sciences》2013,102(1):207-233

New zircon and apatite fission-track (FT) data, including apatite thermal modelling, are combined with an extensive literature survey and reconnaissance-type structural fieldwork in the Eastern Apuseni Mountains. This leads to a better understanding of the complex structural and thermal history of a key area at the boundary between two megatectonic units in the Balkan peninsula, namely the Tisza and Dacia Mega-Units. Following Late Jurassic obduction of the Transylvanian ophiolites onto a part of the Dacia Mega-Unit, that is, the Biharia nappe system, both units were buried to a minimum of 8 km during late Early Cretaceous times when these units were underthrust below the Tisza Mega-Unit consisting of the present-day Codru and Bihor nappe systems. Tisza formed the upper plate during Early Cretaceous (‘Austrian’) east-facing orogeny. Turonian to Campanian zircon FT cooling ages (95–71 Ma) from the Bihor and Codru nappe systems and the Biharia and Baia de Arie? nappes (at present the structurally lowest part of the Dacia Mega-Unit) record exhumation that immediately followed a second Cretaceous-age (i.e. Turonian) orogenic event. Thrusting during this overprinting event was NW-facing and led to the overall geometry of the present-day nappe stack in the Apuseni Mountains. Zircon FT ages, combined with thermal modelling of the apatite FT data, show relatively rapid post-tectonic cooling induced by a third shortening pulse during the latest Cretaceous (‘Laramian’ phase), followed by slower cooling across the 120°–60 °C temperature interval during latest Cretaceous to earliest Paleogene times (75–60 Ma). Cenozoic-age slow cooling (60–40 Ma) was probably related to erosional denudation postdating ‘Laramian’ large-scale updoming.  相似文献   

Micro-XANES determination of ferric iron and its application in thermobarometry   总被引：15，自引：0，他引：15  

R. Schmid  M. Wilke  R. Oberhnsli  K. Janssens  G. Falkenberg  L. Franz  A. Gaab 《Lithos》2003,70(3-4):381-392

Micro-X-ray absorption near-edge structure (XANES) analysis was employed to determine the content of ferric iron in minerals formed in ultrahigh-pressure (UHP) eclogites. It is observed that omphacite and phengite contain significant amounts of Fe³⁺/Fe_tot (0.2–0.6), whereas only very low contents are present in garnet (Fe³⁺/Fe_tot=0.0–0.03), the latter being consistent with results from stoichiometric charge-balance calculations. Furthermore, considerable variations in the Fe³⁺/Fe_tot ratios of omphacite and phengite are observed depending on the textural sites and local bulk chemistry (eclogite and calc-silicate matrix) within one thin section. The oxidation state of isofacial minerals is thus likely to depend on the local fluid composition, which, in the studied case, is controlled by calcareous and meta-basic mineral compositions. These first in-situ measurements of ferric iron in an eclogite sample from the Dabie Shan, E China, are used to recalculate geothermobarometric data. Calculations demonstrate that the temperature during UHP metamorphism was as high as 780 °C, about 80–100 °C higher than previously estimated. Temperatures based on charge balance calculations often give erroneous results. Pressure estimates are in good agreement with former results and confirm metamorphism in the stability field of diamond (43.7 kbar at 750 °C). These P–T data result in a geothermal gradient of ca. 6 °C/km during UHP metamorphism in the Dabie Shan. However, accounting for ferric iron contents in geothermobarometry creates new difficulties inasmuch as calibrations of geothermometers may not be correctable for Fe³⁺ and the actual effect on Mg–Fe²⁺ partitioning is unknown. The present study further shows that micro-XANES is a promising technique for the in situ determination of ferric iron contents without destroying the textural context of the sample: a clear advantage compared to bulk methods.  相似文献   

Dense 3D displacement vector fields for point cloud-based landslide monitoring     

Gojcic  Zan  Schmid  Lorenz  Wieser  Andreas 《Landslides》2021,18(12):3821-3832

Landslides - We propose a novel fully automated deformation analysis pipeline capable of estimating real 3D displacement vectors from point cloud data. Different from the traditional methods that...  相似文献   

Comment on Rosenberg and Garcia: Estimating displacement along the Brenner Fault and orogen-parallel extension in the Eastern Alps, Int J Earth Sci (Geol Rundsch) (2011) 100:1129–1145     

Bernhard Fügenschuh  Neil S. Mancktelow  Stefan S. Schmid 《International Journal of Earth Sciences》2012,101(5):1451-1455

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Characteristics of collisional orogens with low topographic build‐up: an example from the Carpathians     

Liviu Matenco  Csaba Krézsek  Sandra Merten  Stefan Schmid  Sierd Cloetingh  Paul Andriessen 《地学学报》2010,22(3):155-165

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