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1.
Dr. Klaus-Werner Damm Dr. Siegfried Pichowiak Professor Dr. Werner Zeil 《International Journal of Earth Sciences》1981,70(3):1054-1076
Extended deep plutons of the Chilean Coast-Range can, according to their composition, age and spatial distribution, be assigned to the following three Superunits, each of which represents a closed magmatic cycle. Albayay-Superunit approximately 300-200 m. a. Cifuncho-Superunit approximately 190-130 m. a. Esmeralda-Superunit less than 130 m. a.Structurally we distinguished five large batholithic complexes, which are tectonically displaced along vertical fault-planes. The petrographie composition ranges from gabbronoritic through dioritic up to granitic rocks with predominance of granitoids.Methodical investigation led beyond the explanation of the origin of the magma, and opened the way for new geogynamic interpretations. We postulate a model of repeated crustal thickening caused by continental collision, which is opposed to the schematic plate-tectonics model.
Zusammenfassung In der Küstenkordillere Nordchiles lassen sich ausgedehnte Tiefengesteinskörper nach Stoffbestand, Alter und rÄumlicher Verteilung folgenden drei Superunits zuordnen, die jeweils einem abgeschlossenen magmatischen Zyklus entsprechen. Albayay-Superunit ca. 300-200 m. a. Cifuncho-Superunit ca. 190-130 m. a. Esmeralda-Superunit jünger als 130 m. a.Strukturell haben wir fünf grö\ere, durch Tektonik entlang vertikaler Brüche zerlegte Baholith-Komplexe ausgeschieden. Die petrologische Zusammensetzung reicht von gabbro-noritischen über dioritische bis zu granitischen Gesteinen, wobei der Schwerpunkt bei den Granitoiden liegt.Die methodische Untersuchung führte über die KlÄrung der Magmengenese hinaus und eröffnete den Zugang zu neuen geodynamischen Vorstellungen. Wir postulieren ein Modell einer mehrphasigen Krustenverdickung durch kontinentale Kollision, das im Gegensatz zu dem schematischen Modell der Plattentektonik steht.
Resumen En la Cordillera de la Costa del Norte de Chile existen extensos cuerpos intrusivos que se queden asignar, sobre la base de su composición, edad y distribución espacial, a las tres Superunidades siguientes, las que a su vez corresponden a ciclos magmáticos completos. Superunidad-Albayay approximadamente 300-200 m.a. Superunidad-Cifuncho approximadamente 190-130 m.a. Superunidad-Esmeralda más jóvenque 130 m.a.Estructuralmente hemos distinguido cinco complejos batoliticos mayores recortados por una tectónica de fallas verticales. La compositión petrográfica va desde rocas gabronoríticas hasta graníticas pasando por las dioríticas, con predominio de granitoides.El análisis metódico de los datos obtenidos orientado a la petrogénesis de estos cuerpos dió lugar a nuevas interpretaciones geodinámicas. Postulamos un modelo de fases sucesivas de acumulación cortical mediante colisión continental, el cual se opone al esquemático modelo de la Tectónica de Placas.
, , : Albayay-Superunit ... 300-200 Cifuncho-Superunit ... 190-130 Esmeralda-Superunit ... 130 . 5 . - , , . y ; .相似文献
2.
Dr. Klaus-Werner Tietze 《International Journal of Earth Sciences》1978,67(3):1016-1033
Field research of wave generated bed forms within complex sediment size distributions near the inlet of a tidal lagoon at the northern coast of Brittany has stimulated an experimental study in a laboratory wave tank. Several sediment mixtures, most of them with bimodal grain size distributions, were exposed to different monochromatic shallow water waves. The observations and measurements included the dynamics of the water waves and the generation, shape, and size of oscillatory bed forms. The experiments confirm the known relationship between grain size and ripple size. In addition it is shown that coarse sand, added to a preexisting fine bed material leads to an increasing asymmetry of ripples. There is some suggestion that the variability of ripple heights is reduced by higher contents of coarse sand. Bimodal sediment size distributions obviously do not cause unusual geometry of ripples — at least within the range of the experimental tests. The different sand size modes move together in one phase, forming structures with more or less homogeniously distributed bed material. Differentiation of sediment sorting does of course occur, but this is in the range of the whole test section. Finally the experiments allowed to test the validity of some wave formulas. The own experiments are compared with some results from field and laboratory studies of other authors. 相似文献
3.
The use of CODAR by the University of Hamburg has extended to a wide variety of experimental and oceanographic activities over the last three years. These have ranged from Arctic studies from land and ships to observations of the Dead Sea, all yielding surface current data. Hardware improvements have been investigated, including IF amplifier changes and loop-antenna arrays for shipboard operation. 相似文献
4.
Wei Shen Klaus-Werner Gurgel George Voulgaris Thomas Schlick Detlef Stammer 《Ocean Dynamics》2012,62(1):105-121
Land-based high-frequency (HF) radars have the unique capability of continuously monitoring ocean surface environments at
ranges up to 200 km off the coast. They provide reliable data on ocean surface currents and under slightly stricter conditions
can also give information on ocean waves. Although extraction of wind direction is possible, estimation of wind speed poses
a challenge. Existing methods estimate wind speed indirectly from the radar derived ocean wave spectrum, which is estimated
from the second-order sidebands of the radar Doppler spectrum. The latter is extracted at shorter ranges compared with the
first-order signal, thus limiting the method to short distances. Given this limitation, we explore the possibility of deriving
wind speed from radar first-order backscatter signal. Two new methods are developed and presented that explore the relationship
between wind speed and wave generation at the Bragg frequency matching that of the radar. One of the methods utilizes the
absolute energy level of the radar first-order peaks while the second method uses the directional spreading of the wind generated
waves at the Bragg frequency. For both methods, artificial neural network analysis is performed to derive the interdependence
of the relevant parameters with wind speed. The first method is suitable for application only at single locations where in
situ data are available and the network has been trained for while the second method can also be used outside of the training
location on any point within the radar coverage area. Both methods require two or more radar sites and information on the
radio beam direction. The methods are verified with data collected in Fedje, Norway, and the Ligurian Sea, Italy using beam
forming HF WEllen RAdar (WERA) systems operated at 27.68 and 12.5 MHz, respectively. The results show that application of
either method requires wind speeds above a minimum value (lower limit). This limit is radar frequency dependent and is 2.5
and 4.0 m/s for 27.68 and 12.5 MHz, respectively. In addition, an upper limit is identified which is caused by wave energy
saturation at the Bragg wave frequency. Estimation of this limit took place through an evaluation of a year long database
of ocean spectra generated by a numerical model (third generation WAM). It was found to be at 9.0 and 11.0 m/s for 27.68 and
12.5 MHz, respectively. Above this saturation limit, conventional second-order methods have to be applied, which at this range
of wind speed no longer suffer from low signal-to-noise ratios. For use in operational systems, a hybrid of first- and second-order
methods is recommended. 相似文献
5.
6.
Alexander Port Klaus-Werner Gurgel Joanna Staneva Johannes Schulz-Stellenfleth Emil V. Stanev 《Ocean Dynamics》2011,61(10):1567-1585
Tidal and wind-driven surface currents in the German Bight between shallow mudflats of the North Frisian islands and the island
of Helgoland are studied using coastal high-frequency radar (HFR) observations and hindcasts from a primitive equation numerical
model. The setup of the observational system is described, and estimates of expected measurement errors are given. A quantitative
comparison of numerical model results and observations is performed. The dominant tidal components are extracted from the
two data sources using tidal harmonic analysis and the corresponding tidal ellipses are defined. Results show that the spatial
patterns of different tidal ellipse parameters are consistent in the two data sets. Model sensitivity studies with constant
and variable salinity and temperature distributions are used to study density-related mechanisms of circulation. Furthermore,
the role of the surface wind field in driving the German Bight circulation is investigated using the complex correlation between
wind and surface current vectors. The observed change of the respective correlation patterns from the coastal to open ocean
is shown to be due to a combination of density effects, the coastline and topography. The overall conclusion is that HFR observations
resolve the small-scale and rapidly evolving characteristics of coastal currents well in the studied area and could present
an important component for regional operational oceanography when combined with numerical modelling. Some unresolved issues
associated with the complex circulation and large instability of circulation in front of the Elbe River Estuary justify further
considerations of this area using dedicated surveys and modelling efforts. 相似文献
7.
H. -H. Essen
. Breivik H. Gü nther K. -W. Gurgel J. Johannessen H. Klein T. Schlick M. Stawarz 《Journal of Atmospheric & Ocean Science》2003,9(1):39-64
Data from two six-week current measurement campaigns at the coasts of Norway and Spain are presented. Spatial coverage of surface currents was obtained by an HF (High Frequency) radar. Subsurface currents were measured by bottom-mounted and ship-borne ADCPs (Acoustic Doppler Current Profiler). The HF data were assimilated by a fine gridded model with the aim of predicting currents for about 6 h. The objective of this article is twofold, to investigate the performance of the instruments and the model, and to show the high temporal and spatial variability of currents in the coastal zones under investigation.
Several strong storms occurred during the experiments with significant waveheights exceeding 11 m (Norway) and 8 m (Spain), respectively. High waves affected both the WEllen RAdar (WERA) (reduced ranges) and the ADCP (unreliable near-surface current velocities). The assimilation algorithm of the model worked well. The comparisons of measured and modelled maps of the surface-current velocity, time series and horizontal gradients reveal good agreement.
The analysis of current data shows similar features for both experimental areas. The dominant M2-tidal currents are weak (amplitudes of about 0.15 ms -1 ). The spatial distribution of the vector correlation between surface current and wind is homogeneous, although single current maps contain strong horizontal variabilities. The portion of current variance linearly forced by wind is about 30%. 相似文献
Several strong storms occurred during the experiments with significant waveheights exceeding 11 m (Norway) and 8 m (Spain), respectively. High waves affected both the WEllen RAdar (WERA) (reduced ranges) and the ADCP (unreliable near-surface current velocities). The assimilation algorithm of the model worked well. The comparisons of measured and modelled maps of the surface-current velocity, time series and horizontal gradients reveal good agreement.
The analysis of current data shows similar features for both experimental areas. The dominant M2-tidal currents are weak (amplitudes of about 0.15 ms -1 ). The spatial distribution of the vector correlation between surface current and wind is homogeneous, although single current maps contain strong horizontal variabilities. The portion of current variance linearly forced by wind is about 30%. 相似文献
8.
9.
On the accuracy of current measurements by means of HF radar 总被引：3，自引：0，他引：3
The accuracy of surface current velocities measured by high-frequency (HF) radar is investigated. Data from the two radar systems of the University of Hamburg, CODAR (Coastal Radar) and WERA (Wellen Radar), are compared with in situ data. In one experiment, CODAR and a near-surface current meter were operated simultaneously over a 19-day period. In addition, WERA was operated for 6 days during that period. In the other experiment, WERA and a bottom-mounted current meter were operated simultaneously over a 35-day period. Both radars use frequencies of about 30 MHz where backscattering is due to ocean waves of 5 m wavelength. The influence of the orbital motion of underlying longer waves on radial velocity errors is investigated. In accordance with theory, the measured standard deviations of HF-measured current velocities depend on the sea state. Depending on the sea state, estimated errors range from 3 to 10 cm·s-1 and explain only part of the rms difference of 10-20 cm·s-1 found between HF and in situ current measurements. The rest is assumed to be due the differences of the quantities measured, e.g., the spatial averaging 相似文献
10.
High-frequency (HF) radars have been developed to map surface currents offshore by means of land-based stations. Presently available radar systems use frequencies between 25 and 30 MHz and allow a spatial resolution of 1 km and ranges of up to 50 km. This paper reports on the experience with a shipborne radar and discusses problems which arise for the azimuthal resolution on a metal ship, the correction for the ship's speed, and limitations due to pitch-and-roll motions. Current measurements during cruises to the North Atlantic are presented. It has been found that, with the support of the satellite-supported Global Positioning System, the shipborne HF radar can measure surface current velocities with an accuracy of some 5 cm·s-1 相似文献