Bastille Day Event: A Radio Perspective     

Reiner  M.J.  Kaiser  M.L.  Karlický  M.  Jiřička  K.  Bougeret  J.-L. 《Solar physics》2001,204(1-2):121-137

We describe the radio signatures that led up to and concluded the solar eruptive event of 14 July 2000 (Bastille Day Event). These radio signatures provide a means of remotely sensing the associated solar activity and transient phenomena. For many days prior to the Bastille Day Event kilometric Type III radio storm emissions were observed that were presumably associated with the active region NOAA 9077. These storm emissions continued until the X5.7 flare at ∼ 10 UT on 14 July 2000 that characterized the Bastille Day Event, then ceased abruptly. The Bastille Day Event itself produced very intense, complex, long-duration Type III-like radio emissions, which appear to have been associated with electrons generated (accelerated) deep in the solar corona. The coronal mass ejection (CME) associated with the Bastille Day Event generated decametric to kilometric Type II radio emissions as the CME propagated through the solar corona and interplanetary medium. The frequency drift of these Type II radio emissions are related to the dynamics of the propagating CME and indicate that the CME experienced significant deceleration as it propagated from the high corona into the interplanetary medium.  相似文献   

A GPS-Based Online Control and Alarm System     

Simone Kälber  Reiner Jäger  Rainer Schwäble 《GPS Solutions》2000,3(3):19-25

A global positioning system (GPS)-based online control and alarm system (GOCA) for monitoring of three-dimensional movements has been developed at the Karlsruhe University of Technology. The GOCA hardware consists of an array of GPS sensors and communication units to be placed in the monitoring area. The hardware-dependent control software communicates with the GPS sensors and provides the GPS baseline data and covariance information to the GOCA deformation analysis software. The GOCA center, which comprises both the control software and the GOCA software, may be linked – for example, over a long distance – to another personal computer (PC) that serves as a remote control station. GOCA is able to provide the full capabilities of classical deformation analysis online (with stations grouped into stable points and moving object points). Both types of points may be occupied either continuously or over short periods at different times. The object points are determined with respect to the stable points. A network adjustment is performed for each interval of data collection, and the coordinate and covariance information may optionally be transformed into a specific reference system (e. g., the building system). Unstable reference points are to be detected by statistical tests. The estimated object point time series are filtered with respect to gross errors using robust estimation techniques. Online filters are used to smooth the time series data of critical displacements and to predict other deformation functions. The time series data, as well as prediction results, are displayed graphically for each object point. An example concerning the online monitoring of a slag heap in a coal-mining area is included. ? 2000 John Wiley & Sons, Inc.  相似文献   

Program News Bright Prospects for a Significant Improvement of the Earth's Gravity Field Knowledge     

Reiner Rummel 《Marine Geodesy》2000,23(3):219-220

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The Jovian atmospheric window at 2.7 μm: A search for H₂S     

Harold P. Larson  D. Scott Davis  Reiner Hofmann  Gordon L. Bjoraker 《Icarus》1984,60(3):621-639

The atmospheric transmission window at 2.7 μm in Jupiter's atmosphere was observed at a spectral resolution of 0.1 cm^?1 from the Kuiper Airborne Observatory. From analysis of the CH₄ abundance (～80m-am) and the H₂O abundance (<0.0125cm-am) it was determined that the penetration depth of solar flux at 2.7 μm is near the base of the NH₃ cloud layer. The upper limit to H₂O at 2.7 μm and other recent results suggest that photolytic reactions in Jupiter's lower troposphere may not be as significant as was previously thought. The search for H₂S in Jupiter's atmosphere yielded an upper limit of ～0.1cm-am. The corresponding limit to the elemental abundance ratio [S]/[H] was ～1.7 × 10^?8, about 10^?3 times the solar value. Upon modeling the abundance and distribution of H₂S in Jupiter's atmosphere it was concluded that, contrary to expectations, sulfur-bearing chromophores are not present in significant amounts in Jupiter's visible clouds. Rather, it appears that most of Jupiter's sulfur is locked up as NH₄SH in a lower cloud layer. Alternatively, the global abundance of sulfur in Jupiter may be significantly depleted.  相似文献   

Constraints on the source of Cu in a submarine magmatic-hydrothermal system,Brothers volcano,Kermadec island arc     

Manuel?KeithEmail author  Karsten?M.?Haase  Reiner?Klemd  Daniel?J.?Smith  Ulrich?Schwarz-Schampera  Wolfgang?Bach 《Contributions to Mineralogy and Petrology》2018,173(5):40

Most magmatic-hydrothermal Cu deposits are genetically linked to arc magmas. However, most continental or oceanic arc magmas are barren, and hence new methods have to be developed to distinguish between barren and mineralised arc systems. Source composition, melting conditions, the timing of S saturation and an initial chalcophile element-enrichment represent important parameters that control the potential of a subduction setting to host an economically valuable deposit. Brothers volcano in the Kermadec island arc is one of the best-studied examples of arc-related submarine magmatic-hydrothermal activity. This study, for the first time, compares the chemical and mineralogical composition of the Brothers seafloor massive sulphides and the associated dacitic to rhyolitic lavas that host the hydrothermal system. Incompatible trace element ratios, such as La/Sm and Ce/Pb, indicate that the basaltic melts from L’Esperance volcano may represent a parental analogue to the more evolved Brothers lavas. Copper-rich magmatic sulphides (Cu?>?2 wt%) identified in fresh volcanic glass and phenocryst phases, such as clinopyroxene, plagioclase and Fe–Ti oxide suggest that the surrounding lavas that host the Brothers hydrothermal system represent a potential Cu source for the sulphide ores at the seafloor. Thermodynamic calculations reveal that the Brothers melts reached volatile saturation during their evolution. Melt inclusion data and the occurrence of sulphides along vesicle margins indicate that an exsolving volatile phase extracted Cu from the silicate melt and probably contributed it to the overlying hydrothermal system. Hence, the formation of the Cu-rich seafloor massive sulphides (up to 35.6 wt%) is probably due to the contribution of Cu from a bimodal source including wall rock leaching and magmatic degassing, in a mineralisation style that is hybrid between Cyprus-type volcanic-hosted massive sulphide and subaerial epithermal–porphyry deposits.  相似文献   

Formation of carbonate concretions in surface sediments of two mud mounds,offshore Costa Rica: a stable isotope study     

Vasileios?MavromatisEmail author  Reiner?Botz  Mark?Schmidt  Volker?Liebetrau  Christian?Hensen 《International Journal of Earth Sciences》2014,103(7):1831-1844

The surface sediments of two mud mounds (“Mound 11” and “Mound 12”) offshore southwest Costa Rica contain abundant authigenic carbonate concretions dominated by high-Mg calcite (14–20 mol-% MgCO₃). Pore fluid geochemical profiles (sulfate, sulfide, methane, alkalinity, Ca and Mg) indicate recent carbonate precipitation within the zone of anaerobic oxidation of methane (AOM) at variable depths. The current location of the authigenic carbonate concretions is, however, not related to the present location of the AOM zone, suggesting mineral precipitation under past geochemical conditions as well as changes in the flow rates of upward migrating fluids. Stable oxygen and carbon isotope analysis of authigenic carbonate concretions yielded δ¹⁸O_carbonate values ranging between 34.0 and 37.7 ‰ Vienna standard mean ocean water (VSMOW) and δ¹³C_carbonate values from ?52.2 to ?14.2 ‰ Vienna Pee Dee belemnite (VPDB). Assuming that no temperature changes occurred during mineral formation, the authigenic carbonate concretions have been formed at in situ temperature of 4–5 °C. The δ¹⁸O_carbonate values suggest mineral formation from seawater-derived pore fluid (δ¹⁸O_porefluid = 0 ‰ VSMOW) for Mound 12 carbonate concretions but also the presence of an emanating diagenetic fluid (δ¹⁸O_porefluid ≈5 ‰) in Mound 11. A positive correlation between δ¹³C_carbonate and δ¹⁸O_carbonate is observed, indicating the admixing of two different sources of dissolved carbon and oxygen in the sediments of the two mounds. The carbon of these sources are (1) marine bicarbonate (δ¹³C_porefluid ≈0 ‰) and (2) bicarbonate which formed during the AOM (δ¹³C_porefluid ≈?70 ‰). Furthermore, the δ¹⁸O_porefluid composition, with values up to +4.7 ‰ Vienna standard mean ocean water (VSMOW), is interpreted to be affected by the presence of emanating, freshened and boron-enriched fluids. Earlier, it has been shown that the origin of ¹⁸O-enriched fluids are deep diagenetic processes as it was indicated by the presence of methane with thermogenic signature (δ¹³C_CH4 = ?38 ‰). A combination of present geochemical data with geophysical observations indicates that Mounds 11 and 12 represent a single fluid system interconnected by deep-seated fault(s).  相似文献   

Potential of groundwater contamination by polybrominated diphenyl ethers (PBDEs) in a sensitive bedrock aquifer (Canada)     

Jana Levison  Kent Novakowski  Eric J. Reiner  Terry Kolic 《Hydrogeology Journal》2012,20(2):401-412

It is necessary to understand the presence, movement, and persistence of contaminants in aquifers to develop adequate groundwater protection plans. Fractured bedrock aquifers with thin overburden cover are very sensitive to contamination, and little is known about transport processes from the ground surface to depth in this setting. This study was undertaken to investigate the potential of groundwater contamination by polybrominated diphenyl ethers (PBDEs), which are flame retardants, in a natural fractured bedrock aquifer in Canada proven to be sensitive to contamination. PBDEs, which had not been previously measured in groundwater in detail, were detected in the study aquifer at concentrations greater than those observed in surface-water bodies. Potential sources include manure, septic tanks, and the atmosphere. From this scoping study, it is evident that additional surveys of PBDE concentrations in groundwater are warranted, especially in settings with high potential source concentrations coupled with sensitive aquifers.  相似文献   

Program News Bright Prospects for a Significant Improvement of the Earth's Gravity Field Knowledge     

Reiner Rummel 《Marine Geodesy》2013,36(3):219-220

Concern over the impact of change in sea level is of topical interest internationally, but for the small island states of the Caribbean, a significant increase would prove to be catastrophic. The potential problem is being addressed as part of the much larger issue of climate change, and just this year a regional Climate Change Centre was established in Belize. Means of adapting to accommodate change will be considered under the Mainstream Adaptation to Climate Change (MACC) project, but initially the threat needs to be quantified. While meteorological offices have been accumulating weather data in some parts of the region for many years, sea level data is more scarce. This work puts least squares methods to test by applying them to spectral analysis of intermittent data sets acquired over periods of 6 and 9 years at two locations in Trinidad. The resulting sea level models that include 13 periodic components, datum bias, trend and atmospheric pressure are validated using fundamental historical information and observations that form the subject of discussion among local professional surveyors. Results show that while sea level at a location in North Trinidad is rising at the rate of about 1 mm a year, the change at a Southern site is about four times this amount. Horizontal movement has been measured across a tectonic fault that parts the island, and it is now apparent that there may be some vertical motion on this or some other fault lines in the region.  相似文献   

A mesocosm experiment investigating the effects of substratum quality and wave exposure on the survival of fish eggs     

Stefan Stoll  Wolfgang Nikolaus Probst  Reiner Eckmann  Philipp Fischer 《Aquatic Sciences - Research Across Boundaries》2010,72(4):509-517

In a mesocosm experiment, the attachment of bream (Abramis brama) eggs to spawning substrata with and without periphytic biofilm coverage and their subsequent survival with and without low-intensity wave exposure were investigated. Egg attachment was reduced by 73% on spawning substrata with a natural periphytic biofilm, compared to clean substrata. Overall, this initial difference in egg numbers persisted until hatching. The difference in egg numbers was even increased in the wave treatment, while it was reduced in the no-wave control treatment. Exposure to a low-intensity wave regime affected egg development between the two biofilm treatments differently. Waves enhanced egg survival on substrata without a biofilm but reduced the survival of eggs on substrata with biofilm coverage. In the treatment combining biofilm-covered substrata and waves, no attached eggs survived until hatching. In all treatments, more than 75% of the eggs became detached from the spawning substrata during the egg incubation period, and <1% of these detached eggs survived within the substratum interstices. Hence, detached eggs contributed little to the reproductive success we observed. The implications of these results on the spawning success of fish species that use freshly inundated spawning substrata in shallow waters are discussed.  相似文献   

Fluid influence on mineral reactions in ultrahigh-pressure granulites: a case study in the Śnieżnik Mts. (West Sudetes, Poland)     

Reiner Klemd  Michael Bröcker 《Contributions to Mineralogy and Petrology》1999,136(4):358-373

Small tectonic slices of undeformed eclogites and ultrahigh-pressure granulites occur in three tectonic units of the Śnieżnik Mts. (SW Poland). Ultrahigh-pressure granulite/eclogite transitions with peak metamorphic conditions between 21 and 28 kbar at 800 to 1000 °C occur only in the Złote unit. Conventional U-Pb multigrain analyses of zircons from a mafic granulite provided ²⁰⁷Pb/²⁰⁶Pb ages between 360 to 369 Ma which are interpreted to approximate timing of original crystallisation from a melt. Diffusion kinetics and the restricted availability of a fluid phase mainly controlled the conversion from granulite to eclogite, although some bulk-chemical differences were also recognised. The ultrahigh-pressure granulites from the Złote unit exclusively contain H₂O-rich inclusions with variable salinities which distinguishes them from high-temperature (HT)-granulites world-wide. This is also in contrast to the fluid regime (H₂O-N₂-CO₂) recognised in the lower-temperature eclogites (600–800 °C) from the closely associated Międzygórze and Śnieżnik units. The variation in fluid composition between the lower-temperature eclogites and ultrahigh-pressure granulites on the one hand and ultrahigh-pressure granulites and HT-granulites on the other hand probably indicates contrasting P-T-t paths as a result of different tectonic environments. Received: 15 June 1998 / Accepted: 2 March 1999  相似文献