An Mw based earthquake Catalogue for central, northern and northwestern Europe using a hierarchy of magnitude conversions   总被引：3，自引：1，他引：3  

G. Grünthal  R. Wahlström 《Journal of Seismology》2003,7(4):507-531

Data from 25 local catalogues and 30special studies of earthquakes in central,northern and northwestern Europe have beenincorporated into a Databank. The dataprocessing includes discriminating eventtypes, eliminating fake events and dupletsand converting different magnitudes andintensities to M_w if this is not givenby the original source. The magnitudeconversion is a key task of the study andimplies establishment of regressionequations where no local relations exist.The Catalogue contains tectonic events fromthe Databank within the area44°N–72°N,25°W–32°E and the time period1300–1993. The lower magnitude level forthe Catalogue entries is setat M_w == 3.50. The area covered by thedifferent catalogues are associated withpolygons. Within each polygon only datafrom one or a small number of the localcatalogues, supplemented by data fromspecial studies, enter the Catalogue. Ifthere are two or more such catalogues orstudies providing a solution for an event,a priority algorithm selects one entry forthe Catalogue. Then M_w is calculatedfrom one of the magnitude types, or frommacroseismic data, given by the selectedentry according to another priority scheme.The origin time, location, M_w magnitude and reference are specified for eachentry of the Catalogue. So is theepicentral intensity, I₀, if providedby the original source. Following thesecriteria, a total of about 5,000earthquakes constitute the Catalogue.Although originally derived for the purposeof seismic hazard calculation within GSHAP,the Catalogue provides a data base for manytypes of seismicity and seismic hazardstudies.  相似文献   

Anomalous Gadolinium,Cerium, and Yttrium Contents in the Adige and Isarco River Waters and in the Water of Their Tributaries (Provinces Trento and Bolzano/Bozen,NE Italy)     

Peter Mller  Giulio Morteani  Peter Dulski 《洁净——土壤、空气、水》2003,31(3):225-239

Rare earth patterns of surface and groundwaters near big cities often show anthropogenic Gd (Gd_ant) anomalies in addition to geogenic Ce and Y anomalies. The Gd_ant anomaly is caused by very stable organic complexes, one of which is gadopentetic acid, Gd‐DTPA. Derivatives of this and similar compounds are used as contrast agents in magnetic resonance imaging (MRI) of the human blood system. The organic Gd complexes are stable enough to pass nearly unaffected through sewage treatment plants and are, thereafter, discharged into surface water systems. Water of the rapidly flowing Isarco/Eisack and Adige/Etsch rivers (Provinces of Trento and Bolzano/Bozen, NE Italy) and their tributaries show remarkable variations in anthropogenic Gd contents (Gd_ant). Low Gd_ant values are found on Monday and Tuesday, whereas high values are observed during the remaining weekdays. Reliable Gd_ant balances are calculated for the river system at the confluence of the Adige and its tributaries. At two places local decrease of Gd_ant indicates exfiltration of groundwater. It is demonstrated that Gd_ant can be used as a reliably conservative tracer to study the water budget in rapidly flowing alpine river systems. The studied different river waters show considerable negative Ce and positive Y anomalies. Negative Ce anomalies are caused by scavenging of Ce(III) by FeO(OH) precipitates and subsequent oxidation to CeO₂. Y anomalies are attributed to less sorption of Y than REE onto particulate matter. Thus, Y moves faster than REE. Both, Ce and Y anomalies, are of geogenic origin.  相似文献   

The tectonic regime in Italy inferred from borehole breakout data     

Maria Teresa Mariucci  Birgit Müller   《Tectonophysics》2003,361(1-2):21-35

In Italy, the horizontal stress directions are well constrained in many regions, but the tectonic regime is not well known because the stress magnitudes are unknown. Our intention is to improve the knowledge of crustal stress in Italy, both at shallow depth and in low seismicity areas. Therefore, we inferred the tectonic regime from the comparison between the depth of breakout occurrence and the physical properties of the rocks in 20 boreholes. The critical value of the maximum horizontal stress, for which the effective tangential stress at the borehole wall overcomes the rock strength to form breakouts, could be computed from rock strength and density. Comparing the theoretical stress distributions for different tectonic regimes with the depth distribution of breakout occurrence, it is possible to infer the tectonic regime that fits best to the breakout depth distribution. We investigated boreholes up to 6 km deep located in different tectonic environments over the Italian peninsula: the Po Plain, the Apenninic chain, the Adriatic foredeep and the Tyrrhenian Quaternary volcanic region. These wells are characterised by breakout data of good quality (A, B and C, according to World Stress Map quality ranking system). The results are in general agreement with the style of faulting derived from earthquake focal mechanisms and other stress indicators. Our results show a predominance of a normal faulting (NF) regime in the inner Apennines and both normal faulting and strike–slip faulting (SS) style in the surrounding regions, possibly also associated with changes in the tectonic regime with depth.  相似文献   

Geoid determination using adapted reference field, seismic Moho depths and variable density contrast   总被引：4，自引：0，他引：4  

H. A. Abd-Elmotaal  N. Kühtreiber 《Journal of Geodesy》2003,77(1-2):77-85

 The traditional remove-restore technique for geoid computation suffers from two main drawbacks. The first is the assumption of an isostatic hypothesis to compute the compensation masses. The second is the double consideration of the effect of the topographic–isostatic masses within the data window through removing the reference field and the terrain reduction process. To overcome the first disadvantage, the seismic Moho depths, representing, more or less, the actual compensating masses, have been used with variable density anomalies computed by employing the topographic–isostatic mass balance principle. In order to avoid the double consideration of the effect of the topographic–isostatic masses within the data window, the effect of these masses for the used fixed data window, in terms of potential coefficients, has been subtracted from the reference field, yielding an adapted reference field. This adapted reference field has been used for the remove–restore technique. The necessary harmonic analysis of the topographic–isostatic potential using seismic Moho depths with variable density anomalies is given. A wide comparison among geoids computed by the adapted reference field with both the Airy–Heiskanen isostatic model and seismic Moho depths with variable density anomaly and a geoid computed by the traditional remove–restore technique is made. The results show that using seismic Moho depths with variable density anomaly along with the adapted reference field gives the best relative geoid accuracy compared to the GPS/levelling geoid. Received: 3 October 2001 / Accepted: 20 September 2002 Correspondence to: H.A. Abd-Elmotaal  相似文献   

A coupled atmosphere/ice/ocean model for the North Sea and the Baltic Sea   总被引：2，自引：0，他引：2  

C. Schrum  U. Hübner  D. Jacob  R. Podzun 《Climate Dynamics》2003,21(2):131-151

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Intercomparison of Stratospheric Chemistry Models under Polar Vortex Conditions     

M. Krämer  Ri. Müller  H. Bovensmann  J. Burrows  J. Brinkmann  E. P. Röth  J.-U. Grooß  Ro. Müller  Th. Woyke  R. Ruhnke  G. Günther  J. Hendricks  E. Lippert  K. S. Carslaw  Th. Peter  A. Zieger  Ch. Brühl  B. Steil  R. Lehmann  D. S. McKenna 《Journal of Atmospheric Chemistry》2003,45(1):51-77

Several stratospheric chemistry modules from box, 2-D or 3-D models, have been intercompared. The intercomparison was focused on the ozone loss and associated reactive species under the conditions found in the cold, wintertime Arctic and Antarctic vortices. Comparisons of both gas phase and heterogeneous chemistry modules show excellent agreement between the models under constrained conditions for photolysis and the microphysics of polar stratospheric clouds. While the mean integral ozone loss ranges from 4–80% for different 30–50 days long air parcel trajectories, the mean scatter of model results around these values is only about ±1.5%. In a case study, where the models employed their standard photolysis and microphysical schemes, the variation around the mean percentage ozone loss increases to about ±7%. This increased scatter of model results is mainly due to the different treatment of the PSC microphysics and heterogeneous chemistry in the models, whereby the most unrealistic assumptions about PSC processes consequently lead to the least representative ozone chemistry. Furthermore, for this case study the model results for the ozone mixing ratios at different altitudes were compared with a measured ozone profile to investigate the extent to which models reproduce the stratospheric ozone losses. It was found that mainly in the height range of strong ozone depletion all models underestimate the ozone loss by about a factor of two. This finding corroborates earlier studies and implies a general deficiency in our understanding of the stratospheric ozone loss chemistry rather than a specific problem related to a particular model simulation.  相似文献   

Climate System Modeling in the Framework of the Tolerable Windows Approach: The ICLIPS Climate Model     

Thomas Bruckner  Georg Hooss  Hans-Martin Füssel  Klaus Hasselmann 《Climatic change》2003,56(1-2):119-137

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A Case Study Of An On-Ice Air Flow Over The Arctic Marginal Sea-Ice Zone     

Timo Vihma  Jörg Hartmann  Christof Lüpkes 《Boundary-Layer Meteorology》2003,107(1):189-217

A case study of warm air advection over the Arctic marginalsea-ice zone is presented, based on aircraft observations with direct flux measurements carriedout in early spring, 1998. A shallow atmospheric boundary layer (ABL) was observed, which wasgradually cooling with distance downwind of the ice edge. This process was mainly connected with astrong stable stratification and downward turbulent heat fluxes of about 10–20 W m^-2, but wasalso due to radiative cooling. Two mesoscale models, one hydrostatic and the other non-hydrostatic,having different turbulence closures, were applied. Despite these fundamental differences betweenthe models, the results of both agreed well with the observed data. Various closure assumptions had amore crucial influence on the results than the differences between the models.Such an assumption was, for example,the parameterization of the surface roughness for momentum (z₀) and heat (z_T). This stronglyaffected the wind and temperature fields not only close to the surface but also within and abovethe temperature inversion layer. The best results were achieved using a formulation for z₀ that took intoaccount the form drag effect of sea-ice ridges together withz_T = 0.1z₀. The stability within theelevated inversion strongly depended on the minimum eddy diffusivity K_min. A simple ad hocparameterization seems applicable, where K_min is calculated as 0.005 timesthe neutral eddy diffusivity. Although the longwave radiative cooling was largest within the ABL, theapplication of a radiation scheme was less important there than above the ABL. This was related to theinteraction of the turbulent and radiative fluxes. To reproduce the strong inversion, it wasnecessary to use vertical and horizontal resolutions higher than those applied in most regional andlarge-scale atmospheric models.  相似文献   

Progress and new directions in high temperature calorimetry revisited     

Alexandra Navrotsky 《Physics and Chemistry of Minerals》1997,24(3):222-241

 High temperature reaction calorimetry has seen considerable advances over the past twenty years. New and more sensitive calorimeters, improved sample handling techniques, and better control of the final dissolved state has made solution calorimetry and drop solution calorimetry, using molten lead borate and other solvents, very versatile and reliable techniques. This paper summarizes these advances and presents examples of specific applications to problems of transition metal oxide chemistry, high pressure geophysics, melt and glass energetics, and metastable materials relevant to the earth sciences. Received June 3, 1996 / Revised, accepted Spetember 23, 1996  相似文献   

Reply to the discussion by N. Beukes and J. Gutzmer     

D. H. Cornell  S. S. Schütte 《Mineralium Deposita》1996,31(3):246-247

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