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排序方式： 共有439条查询结果，搜索用时 19 毫秒
31.
Manfred Baer Nicolas Deichmann Jochen Braunmiller John Clinton Stephan Husen Donat Fäh Domenico Giardini Philipp Kästli Urs Kradolfer Stefan Wiemer 《Swiss Journal of Geoscience》2007,100(3):517-528
This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during
2006. During this period, 572 earthquakes and 91 quarry blasts were detected and located in the region under consideration.
Of these earthquakes, two occurred in conjunction with the construction of the new Gotthard railway tunnel and 165 were induced
artificially by the stimulation of a proposed geothermal reservoir beneath the city of Basel. With 20 events with M
L
≥ 2.5, five of which were artificially induced, the seismic activity in the year 2006 was far below the average over the
previous 31 years. Nevertheless, six events were felt by the public, most prominently the strongest of the induced Basel events
(M
L
3.4), which caused some non-structural building damage. Noteworthy are also the two earthquakes near Cortaillod (M
L
3.2), on the shore of Lake Neuchatel, and in Val Mora (M
L
3.5), between the Engadin and Val Müstair, as well as the 42 aftershocks of the M
L
4.9 Vallorcine earthquake, between Martigny and Chamonix, of September 2005.
Editorial handling: Stefan Bucher 相似文献
32.
Wolfram Wobrock Andrea I. Flossmann Marie Monier Jean-Marc Pichon Laurent Cortez Jean-Franois Fournol Alfons Schwarzenbck Stephan Mertes Jost Heintzenberg Paolo Laj Giordano Orsi Loretta Ricci Sandro Fuzzi Harry Ten Brink Piet Jongejan Ren Otjes 《Atmospheric Research》2001,58(4):7907
The second field campaign of the Cloud Ice Mountain Experiment (CIME) project took place in February 1998 on the mountain Puy de Dôme in the centre of France. The content of residual aerosol particles, of H2O2 and NH3 in cloud droplets was evaluated by evaporating the drops larger than 5 μm in a Counterflow Virtual Impactor (CVI) and by measuring the residual particle concentration and the released gas content. The same trace species were studied behind a round jet impactor for the complementary interstitial aerosol particles smaller than 5 μm diameter. In a second step of experiments, the ambient supercooled cloud was converted to a mixed phase cloud by seeding the cloud with ice particles by the gas release from pressurised gas bottles. A comparison between the physical and chemical characteristics of liquid drops and ice particles allows a study of the fate of the trace constituents during the presence of ice crystals in the cloud.In the present paper, an overview is given of the CIME 98 experiment and the instrumentation deployed. The meteorological situation during the experiment was analysed with the help of a cloud scale model. The microphysics processes and the behaviour of the scavenged aerosol particles before and during seeding are analysed with the detailed microphysical model ExMix. The simulation results agreed well with the observations and confirmed the assumption that the Bergeron–Findeisen process was dominating during seeding and was influencing the partitioning of aerosol particles between drops and ice crystals. The results of the CIME 98 experiment give an insight on microphysical changes, redistribution of aerosol particles and cloud chemistry during the Bergeron–Findeisen process when acting also in natural clouds. 相似文献
33.
Paolo Laj Andrea I. Flossmann Wolfram Wobrock Sandro Fuzzi Giordano Orsi Loretta Ricci Stephan Mertes Alfons Schwarzenbck Jost Heintzenberg Harry Ten Brink 《Atmospheric Research》2001,58(4):256
We investigated the partitioning of trace substances during the phase transition from supercooled to mixed-phase cloud induced by artificial seeding. Simultaneous determination of the concentrations of H2O2, NH3 and black carbon (BC) in both condensed and interstitial phases with high time resolution showed that the three species undergo different behaviour in the presence of a mixture of ice crystals and supercooled droplets. Both H2O2 and NH3 are efficiently scavenged by growing ice crystals, whereas BC stayed predominantly in the interstitial phase. In addition, the scavenging of H2O2 is driven by co-condensation with water vapour onto ice crystals while NH3 uptake into the ice phase is more efficient than co-condensation alone. The high solubility of NH4+ in the ice could explain this result. Finally, it appears that the H2O2–SO2 reaction is very slow in the ice phase with respect to the liquid phase. Our results are directly applicable for clouds undergoing limited riming. 相似文献
34.
Direct effects of pure humic substance (BS1 FA) on three different aquatic organisms (Ceratophyllum demersum, Dreissena polymorpha, and Chaetogammarus ischnus) were demonstrated in this study. Exposure to environmentally relevant concentrations (0.5 mg/L) of this humic substance led to the activation of the microsomal and soluble glutathione S‐transferase (GST) in Ceratophyllum demersum. Exposure to 3‐chlorobiphenyl showed also an elevation of GST activity, which is due to the proposed detoxication metabolism of these chlorinated biphenyl. Coexposure to a mixture of 3‐chlorobiphenyl and BS1 FA showed a reduction of enzyme elevation, but still significant over an untreated control. The direct impact of humic substances seems not to be restricted to a specific class of organisms. 相似文献
35.
Walter Stephan 《International Journal of Earth Sciences》1959,48(1):92-95
Zusammenfassung Auswirkungen der saalischen Phase sind nun auch im Stockheimer Becken erstmals festgestellt. In der Hauptsache ist in diesem Gebiet jedoch mit orogenetischen Bewegungen im Unterrotliegenden selbst zu rechnen. — Der Vulkanismus entwickelte sich im Becken bzw. an seinen Rändern vermutlich bereits im jüngsten Oberkarbon (1. Phase, am stärksten ausgebildet) und hält dann im Unterrotliegenden an (2. Phase, evtl. noch Gehrener Stufe). Aus dem mittleren Rotliegenden sind bisher nur Porphyr-Fanglomerate angeführt worden. Allerdings muß berücksichtigt werden, daß deren Neubearbeitung noch nicht abgeschlossen ist und das Stockheimer Becken ohnehin nur einen kleinen Ausschnitt aus der Gesamtentwicklung am Südwestrand des Frankenwaldes darstellt. Mit einem Vulkanismus im mittleren Rotliegenden (3. Phase, ? Goldlauterer Stufe) ist demnach auch hier noch zu rechnen. 相似文献
36.
Prof. Dr. Stephan Müller 《International Journal of Earth Sciences》1970,59(2):792-805
The occurrence of earthquakes causing damage in regions, where no seismic activity had been observed previously, has confirmed the suspicion that the construction of high dams and pumped storage hydroelectric plants as well as the pressing of fluid into petroleum reservoirs and of waste water into deep boreholes will trigger the release of tectonic stresses in the earth's crust. A great number of examples indicates that a similar mechanism must be operative in all cases. Comparing the results of laboratory experiments to seismological observations, it is evident that the causes for the “loss of internal balance” must be sought in zones of low velocity and of relatively high energy absorption within the upper part of the earth's crust. 相似文献
37.
Dissolution rates of natural illite (Illite du Puy) were measured from Si release rates during closed system experiments at pH ranging from 1.4 to 12.4 and temperatures ranging from 5 to 50°C. Experiments performed at 4<pH<11 exhibited reactive fluid Si/Al concentration ratios that were inconsistent with stoichiometric illite dissolution likely due to secondary phase precipitation. In contrast, after an initial preferential release of aluminum relative to silicon, the reactive fluid Si/Al concentration ratio evolution was consistent with stoichiometric illite dissolution for all experiments conducted at 4>pH>11. Si release rate decreased with time during all experiments; for those experiments performed at 4>pH>11 this observation can be attributed to either 1) changing reactive surface area; 2) the effect of initial fine particle dissolution; or 3) a negative order of the illite dissolution reaction with respect to aqueous Al and/or Si. Measured dissolution rates exhibited a typical variation with pH; rates decrease with increasing pH at acid conditions, minimize at near to neutral pH and increase with increasing pH at basic conditions. An empirical expression describing rates obtained in the present study is given by
38.
Beach-cast wrack of marine origin is considered a spatial subsidy to the marine-terrestrial transition zone. We found that
the wrack line on sand and gravel beaches of Vancouver Island was frequented by intertidal purple shore crabs,Hemigrapsus nudus (Dana 1851) and densely colonized by detritivorous talitrid amphipods. Amphipods spend the day buried in sand and forage
on beach wrack during the night.H. nudus were found in supratidal wrack putches immediately after nightly high tides in field censuses, but spent most of the day
and ebb tides either submerged subtidally or hidden underneath intertidal rocks and boulders. In feeding trials, intertidal
shore crabs were capable of preying on talitrid amphipods. We considerH. nudus an omnivore feeding on both fresh and decaying macroalgae as well as animal prey. Although living supratidally, amphipods
were significantly preferred over intertidal littorine snails by foraging shore crabs. Handling time of amphipods was significantly
shorter than for littorine snails. While amphipods had a reduced risk of predation byH. nudus when buried in the sand, foraging undern eath wrack patches did not reduce predation pressure on amphipods by shore crabs.
Rates of amphipod consumption by shore crabs were higher at darkness than daylight. In addition to an apparent day-night rhythm,
tidal height and time elapsed since previous high tide had a significant influence on shore crab density wrack. We conclude
that beach-cast wrack acts as a spatial subsidy by virtue of providing a valuable food source to talitrid amphipods, which
are in turn consumed by shore crabs that ride the nightly high tide into supratidal wrack patches to reduce the risk of passing
bare sand on theiry way to a feeding habitat rich in valuable prey. 相似文献
39.
Analyses of aircraft observations of the stratocumulus-topped boundary layer during the First ISCCP (International Satellite
Cloud Climatology Project) Regional Experiment (FIRE I) show the frequent presence of clear, but relatively moist, air patches
near the stratocumulus cloud-top interface. A conditional sampling of measurements in these clear air patches shows that their
thermodynamic properties do more resemble boundary-layer air characteristics than those of free troposphere air. From an aircraft
leg through cloud tops it is demonstrated that turbulent mixing across the cloud-top interface can lead to the local dissipation
of the cloud top. Analogous to the terminology used for shallow cumulus parameterizations this process can be considered as
detrainment, with which we mean that after a mixing event across the cloud-top boundaries, mixed unsaturated parcels become
part of the clear environment of the cloud. 相似文献
40.
High resolution 3-cm weather radar was used to observe the three dimensional structure of a weak echo region of a severe convective storm in northern Minnesota, U.S.A. Observations show that a seemingly steady-state updraft in the lower portion of the storm broke into an unsteady structure in the upper levels. This is interpreted as indicating that precipitation loading gradually decelerated the upper reaches of the updraft, resulting in periodic breakout of a new updraft core on the inflow side. This periodic behavior of the updraft may be related to hailstreaks and what has been termed the multi-celled storm. 相似文献