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31.
Long-term Sensor Drift Found in Recovered Argo Profiling Floats   总被引:5,自引:0,他引:5  
We recovered three Argo profiling floats after 2 to 2.5 years of operation, and recalibrated their temperature, conductivity, and pressure sensors. The results demonstrate that these floats exhibited a significant drift in salinity of −0.0074 to −0.0125, primarily due to the conductivity sensor drift. Combined with the recalibration result for another previously recovered float, the indication is that the negative salinity drift increases nearly in proportion to the operating period of floats. The increasing rate is −0.0041 (±0.0015) year−1, which yields a salinity drift of −0.016 (±0.006) for the expected float lifetime of four years. The present result suggests that reducing the float surfacing time would improve the accuracy of the salinity measurements.  相似文献   
32.
Solid-phase microextraction (SPME) is a simple, sensitive and less destructive method for the determination of dimethylsulfide (DMS) in seawater. Combined with detection by gas chromatography-mass spectrometry (GC-MS), the method had sufficient sensitivity (minimum detectable concentration of DMS was 0.05 nM), and practical levels of reproducibility (relative standard deviation ≤7%) and linearity (r 2 > 0.995) over a wide concentration range (0.5 to 910 nM). The protocol developed was applied to a Sagami Bay water sample to determine concentrations of DMS and DMSP, and in situ DMSP-lyase activity.  相似文献   
33.
Eddy Shedding from the Kuroshio Bend at Luzon Strait   总被引:16,自引:1,他引:16  
TOPEX/POSEDIENT-ERS satellite altimeter data along with the mean state from the Parallel Ocean Climate Model result have been used to investigate the variation of Kuroshio intrusion and eddy shedding at Luzon Strait during 1992–2001. The Kuroshio penetrates into the South China Sea and forms a bend. The Kuroshio bend varies with time, periodically shedding anticyclonic eddies. Criteria of eddy shedding are identified: 1) When the shedding event occurs, there are usually two centers of high Sea Surface Height (SSH) together with negative geostrophic vorticity in the Kuroshio Bend (KB) area. 2) Between the two centers of high SSH there usually exists positive geostrophic vorticity. These criteria have been used to determine the eddy shedding times and locations. The most frequent eddy shedding intervals are 70, 80 and 90 days. In both the winter and summer monsoon period, the most frequent locations are 119.5°E and 120°E, which means that the seasonal variation of eddy shedding location is unclear.  相似文献   
34.
In this paper we analyze seismic regime and earthquake depth distribution and correlation of seismicity and mud volcanism in the Azerbaijan and the Caspian Sea region. For the present region we have calculated accurate source locations, seismic activity, earthquake repetition and released earthquake energy parameters. It is shown that the active tectonic processes in the region are concentrated within the thick sedimentary cover that we consider as a general source of contemporary stress and a main structural element responsible for the origin of regional earthquakes. The correlation of seismicity and mud volcanism is of paragenetic character.  相似文献   
35.
Zusammenfassung Obwohl Kohlentonsteine aus dem Saar-Lothringer Oberkarbon seit etwa 170 Jahren bekannt sind, gelang erst in jüngster Zeit der Nachweis und die Identifikation vulkanogener Relikte im petrographischen Stoffbestand. Diese befinden sich in Kohlentonsteinen des Stefan A: KTst 0=950; Westfal D: KTst 1=700; Westfal C: KTst 3 =400, KTst 4a=330, KTst 4aß=322, KTst 4=320, KTst 5=300 und im KTst 6=270. Das entspricht einem Anteil von ca. 18 % an der Gesamtzahl der in diesem limnischen Steinkohlenrevier beobachteten Kohlentonsteine, die hier große praktische und wissenschaftliche Bedeutung besitzen. Die pseudomorphen Relikte bestehen aus kleinen Splittern, kleinen und größeren Fragmenten mit teilweise gut erhaltenem blasigen Gefüge von Vitroklasten — sie zeigen die für Aschenschmelztuffe typisch verschweißte Scherbentextur. Die Glassubstanz ist meist zu mikrokristallinem Kaolinit devitrifiziert. Der eindeutige Nachweis dieser Relikte ist für die Genese bedeutungsvoll, liefern sie doch nun den sicheren Beweis, daß der primäre Stoffbestand aus aerisch abgelagertem pyroklastischen Material bestand, das intensive chemische Verwitterungs- und diagenetische Umbildungsprozesse erfahren hat. Für die 43 Kohlentonsteine des Saar-Lothringer Oberkarbons wird eine pyroklastische Eruptionsmenge von mindestens 8,2 km3 Festvolumen bzw. 20,5 km3 Lokkervolumen angenommen. Die Eruptionen erfolgten vermutlich aus der in der Nähe befindlichen Metz-Hunsrück-Südrand-Tiefenstörung, die nach Reflexionsseismik bis unter die Moho reicht.
Tonsteins in the Carboniferous of the Saar-Lorraine basin are known since about 170 years. Volcanic glass remains, however, have been proven as constituents of the tonstein only recently. They occur in tonsteins of Stephanian A: KTst 0=950; Westphalian D: KTst 1=700; Westphalian C: KTst 3=400, KTst 4a=330, KTst 4aß= 322, KTst 4=320, KTst 5=300 and KTst 6=270. Tonsteins with volcanic glass fragments amount to 18% of the total tonsteins observed in the limnic Saar-Lorraine basin. They are important to applied geology, e.g. for seam identification and correlation, as well as for scientific reasons, namely for the determination of provenance and genesis of tonsteins.The volcanic remains consist of tiny glass splinters, glass fragments, and of fragments with well preserved gasbubble texture. The welded splinter texture is typical of welded pyroclastic ash deposits. Much of the glass has been devitrified to microcrystalline kaolinite. The indisputable evidence of volcanic remains is essential when considering the genesis of tonsteins, as they provide proof that tonsteins are primarily composed of eolian pyroclastic constituents which were altered by chemical weathering and diagenesis.For the 43 horizons of the coal tonsteins found in the Upper Carboniferous of the Saar-Lorraine basin, a pyroclastic eruption quantity of at least 8.2 km3 of solid volume or 20.5 km3 of bulk volume is assumed. The eruptions possibly took place along the nearby deep-seated Metz fault at the southern rim of the Hunsrück. This fault, reaches below the Moho according to reflection seismic.

Résumé Bien que des tonstein du Carbonifère supérieur de SarreLorraine soient connus depuis 170 ans c'est seulement il y a peu de temps que des fragments de verre volcanique y ont été identifiés. Ces fragments ont été rencontrés dans les niveaux de tonstein suivants: Stephanien A: KTst 0=950; Westphalien D: KTst 1=700; Westphalien C: KTst 3=400, KTst 4a=330, KTst 4aß=322, KTst 4=320, KTst 5=300 et KTst 6=270. Ces niveaux représentent une proportion de l'ordre de 18% dans le total des couches de tonstein carbonifère rencontrées dans ce bassin houiller limnique où elles présentent un grand intérêt tant au point de vue pratique que scientifique. Les verres se présentent en esquilles et en fragments de tailles diverses, montrant parfois une structure bulleuse bien conservée; ils présentent également les structures d'agglomération propres aux tufs soudés à chaud. Le verre est le plus souvent dévitrifié en kaolinite microcristalline. La présence de ces fragments est d'un intérêt particulier pour la genèse du dépôt puisqu'elle fournit la preuve que celui-ci était constitué de matériaux primaires pyroclastiques sédimentés dans l'air, matériaux qui ont subi ensuite des altérations chimiques et des transformations diagénétiques intenses.Pour l'ensemble des 43 horizons de tonstein du Carbonifère supérieur de la Sarre-Lorraine, on admet un volume de matières pyroclastiques d'au moins 8,2 km3 (volume à l'état monolithique) ou de 20,5 km3 (volume à l'état fragmenté). Ces éruptions ont probablement pour origine la faille de Metz, située à proximité, qui forme la limite sud du Hunsrück et que la sismique-réflexion permet de prolonger jusqu'au Moho.

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Das Thema dieser Arbeit war Gegenstand des KurzvortragesBurger &Wolf (1987) auf dem XI. ICC in Peking (31. 8. bis 4. 9. 1987). Vorliegende Bearbeitung stellt die originäre Fassung dar.  相似文献   
36.
We report on eight X-ray bursts detected by ASTRON from the Rapid Burster (RB) on 13 and 28 April and 16 August, 1983. Six of them (trailing bursts), with durations of 1.5–2 min, rise times of 5–10 s and intervals of 1–1.5 hours, exhibit spectral softening during the burst decay and may be related to the type I bursts. Two of the bursts (triangle bursts) observed on 28 April at interval of 28 min with much longer rise times (30–50 s) and longer durations (3 min), do not show distinct spectral softening. Persistent flux from RB on 16 August was estimated asF p(2.0–2.4)×10–9 erg cm–2 s–1. Spectral evolution of two trailing bursts was investigated by fitting their spectra in consecutive time intervals with the blackbody (BB), isothermal scattering photosphere (SP) and thermal bremsstrahlung (TB) models. Around the burst maxima the SP model fits the data best whereas in the burst tails the TB model is generally better. The BB model is worse than at least one of the two others. Interpretation of the burst spectra in terms of the BB radiation leads to improbably small neutron star mass and radius (M<0.86M ,R NS<5 km) if the peak luminosity does not exceed the Eddington limit. Interpretation of the spectra around the burst maxima (3–15 s from the burst onset) in terms of an isothermal SP yields reasonable constraints onM,R NS, and distanceD. For instance, for the hydrogen photosphere we obtainedM=(1.0–2.1)M R NS=(7.1–16.4) km ifD=11 kpc. If one postulatesM=1.4M , thenD=(8.5–13) kpc for hydrogen photosphere; if, besides,D=11 kpc, thenR NS=(8.1–13.3) km. It follows also from the SP-interpretation that the photosphere radius may increase up to 20–30 km in maxima of the trailing bursts when the luminosity becomes close to the Eddington luminosity.  相似文献   
37.
The Menilite Shales (Oligocene) of the Polish Carpathians are the source of low-sulfur oils in the thrust belt and some high-sulfur oils in the Carpathian Foredeep. These oil occurrences indicate that the high-sulfur oils in the Foredeep were generated and expelled before major thrusting and the low-sulfur oils in the thrust belt were generated and expelled during or after major thrusting. Two distinct organic facies have been observed in the Menilite Shales. One organic facies has a high clastic sediment input and contains Type-II kerogen. The other organic facies has a lower clastic sediment input and contains Type-IIS kerogen. Representative samples of both organic facies were used to determine kinetic parameters for immiscible oil generation by isothermal hydrous pyrolysis and S2 generation by non-isothermal open-system pyrolysis. The derived kinetic parameters showed that timing of S2 generation was not as different between the Type-IIS and -II kerogen based on open-system pyrolysis as compared with immiscible oil generation based on hydrous pyrolysis. Applying these kinetic parameters to a burial history in the Skole unit showed that some expelled oil would have been generated from the organic facies with Type-IIS kerogen before major thrusting with the hydrous-pyrolysis kinetic parameters but not with the open-system pyrolysis kinetic parameters. The inability of open-system pyrolysis to determine earlier petroleum generation from Type-IIS kerogen is attributed to the large polar-rich bitumen component in S2 generation, rapid loss of sulfur free-radical initiators in the open system, and diminished radical selectivity and rate constant differences at higher temperatures. Hydrous-pyrolysis kinetic parameters are determined in the presence of water at lower temperatures in a closed system, which allows differentiation of bitumen and oil generation, interaction of free-radical initiators, greater radical selectivity, and more distinguishable rate constants as would occur during natural maturation. Kinetic parameters derived from hydrous pyrolysis show good correlations with one another (compensation effect) and kerogen organic-sulfur contents. These correlations allow for indirect determination of hydrous-pyrolysis kinetic parameters on the basis of the organic-sulfur mole fraction of an immature Type-II or -IIS kerogen.  相似文献   
38.
The Plattengneis shear zone is a 250–600 m thick, flat lying, Cretaceous, eclogite facies, mylonitic shear zone, with north-over-south transport direction, that is exposed over almost 1000 km2 in the Koralpe region along the eastern margin of the Alps. Although the shear zone is one of the largest in the Alps, its role in the Eoalpine metamorphic evolution and the subsequent exhumation of the region, remain enigmatic and its large-scale geometry is not well understood. The outcrop pattern suggests that the shear zone is made up of a single sheet that is folded into a series of open syn- and antiforms with wavelengths of about 10 km. Eclogite bodies occur above, within and below the shear zone and there is no metamorphic grade change across the shear zone. In the south, the fold axes strike east–west and plunge shallowly to the east. In the north, the fold axes are oriented in north–south direction and form a dome shaped structure of the shear zone. Total shortening during this late stage warping event was of the order of 5%. Indirect evidence constrains this folding event to have occurred between 80 and 50 Ma and the fold geometry implies that the final exhumation in the Koralpe occurred somewhat later than further north. Interestingly, the shear zone appears to strike out of the topography in the south and dip into the topography in the north, so that north of the shear zone only hanging-wall rocks are exposed and south of it only foot-wall rocks. Possibilities for the geometric relationship of the Plattengneis shear zone with the surrounding south dipping detachments are discussed.  相似文献   
39.
Histograms of observations from spatial phenomena are often found to be more heavy-tailed than Gaussian distributions, which makes the Gaussian random field model unsuited. A T-distributed random field model with heavy-tailed marginal probability density functions is defined. The model is a generalization of the familiar Student-T distribution, and it may be given a Bayesian interpretation. The increased variability appears cross-realizations, contrary to in-realizations, since all realizations are Gaussian-like with varying variance between realizations. The T-distributed random field model is analytically tractable and the conditional model is developed, which provides algorithms for conditional simulation and prediction, so-called T-kriging. The model compares favourably with most previously defined random field models. The Gaussian random field model appears as a special, limiting case of the T-distributed random field model. The model is particularly useful whenever multiple, sparsely sampled realizations of the random field are available, and is clearly favourable to the Gaussian model in this case. The properties of the T-distributed random field model is demonstrated on well log observations from the Gullfaks field in the North Sea. The predictions correspond to traditional kriging predictions, while the associated prediction variances are more representative, as they are layer specific and include uncertainty caused by using variance estimates.  相似文献   
40.
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