ALBERT

Description: The Vrancea region, in the Southeastern Carpathians (Romania), represents a unique case among the seismic areas in the world taking into account the extreme concentration and persistence of seismicity and the tectonic stress field. Subduction in a post-collisional phase is still active in a narrow area located at the sharp bend of the mountain belt. Our goal is to show that the particular shape of the shear-wave splitting can be interpreted in the light of the decoupling and slab-retreat processes, which hypothetically induce a specific configuration of the upper-mantle flow. Shear-wave splitting of SKS phases shows a relatively coherent pattern outside the epicentral area, suggesting a prominent NE-SW anisotropy, in agreement with previous estimations performed in Central and Eastern Europe and following the trends of the deformation field as outlined by the GPS measurements. A clear change is pointed out inside the Vrancea area, where strike-parallel polarization is emphasized. Toward the NW (wedge side), the polarization turns to a strike-perpendicular direction in agreement to an upwelling asthenospheric flow in the back-arc region (i.e., polarization aligned to the local strike of the slab). These shear-wave splitting attributes are not consistent with conventional models of 2-D mantle flow near subduction zones, nor with a sub-vertical down-dipping flow driven by the sinking of the slab. They correlate well with lateral inhomogeneities outlined by the tomography image, heat flow, seismic-wave attenuation and thermal field. We suggest that the eastward slab retreat, and decoupling between the underlying asthenosphere and the slab itself, have induced strike-parallel mantle flow, likely favoring detachment of the slab along the arcuate mountain belt. These processes are directly related to the strong anisotropy observed in the SE Carpathians. The anisotropy and GPS data suggest a strong coupling of the surface and mantle processes.

Description: We present a graphical user interface to facilitate the processing of teleseismic shear-wave splitting observations. In contrast to a fully automated technique, we present a manual, per-event approach that maintains user control during the sequence of processing. The SplitLab environment is intended to undertake the repetitive processing steps while enabling the user to focus on quality control and eventually the interpretation of the results. Pre-processing modules of SplitLab create a database of events and link the corresponding seismogram files. The seismogram viewer tool uses this database to perform the measurement interactively. Post-processing of the combined results of such a project includes a viewer and export option. Our emphasis lies in the application to teleseismic shear-wave splitting analysis, but our code can be extended easily for other purposes.

Description: Seismic anisotropy of the south Iberian upper mantle is investigated using shear-wave splitting of SKS phases. We analyzed teleseismic events recorded by sixteen permanent broadband stations installed on the southern Iberian Peninsula and in northern Africa, and we determined fast polarization directions ϕ, and delay times δt between fast and slow components. The area of investigation extends across two important geological structures in the Variscan Iberian Peninsula: the Variscan Iberian Massif in its center, and the Gibraltar arc in the Southeast, that represents the most westerly Alpine belt in the western Mediterranean. Shear-wave splitting measurements from stations in the Betic domain show homogeneous ENE–WSW fast directions nearly parallel to the trend of the mountain belt, and smooth spatial variations. Stations in the North, toward the southern part of the Variscan Iberian Massif show homogeneous fast directions however trending NS to NE–SW, different from those recorded in the Betic. These observations may reflect a post-Hercynian (Variscan) deformation of the Ossa-Morena zone, related to the main stages in the tectonic evolution of this part, namely transpressional stage, transtensional stage and shortening episode, or a deformation related to the posterior Alpine orogeny. Along the Gibraltar arc, we observe a smoothly varying ϕ trend changing from ENE–WSW in the Eastern Betics to NS in the area of Gibraltar and Ceuta, following more or less the general trend of the mountain belt around the Alboran Sea, and the coastline. Since a similar rotation is also visible in results from Pn anisotropy, this suggests that the anisotropy is vertically coherent starting from just below the Moho. Comparing the anisotropy pattern expected from various geodynamic models with the observed SKS splitting suggests that the anisotropy is best explained by a model of slab rollback, rather than by delamination models.

Description: The International Federation of Digital Seismographic Networks (FDSN) is a non-governmental organization formed by institutions dedicated to seismological research and seismic monitoring. The FDSN is a successful complement to the International Seismological Centre (ISC) in pursuing a more than a century old tradition of global seismic data exchange. The main goal of the FDSN is the production and dissemination of seismic waveform data from high fidelity seismic observatories. The federation is formed by 65 organizations from 52 countries that contribute data to three main data centers in the United States, Europe, and Japan. A subset of the stations that conform the FDSN send real-time to the data management center (DMC) of the Incorporated Research Institutions of Seismology (IRIS) in the United States. Data from this real-time network is crucial to the determination of the seismic parameters of large earthquakes in a very short time after their occurrence and to support the efforts of institutions that are responsible for disaster relief or prevention. Most notably, tsunami warning centers use this information as a fundamental underpinning to issue warnings and alerts. The FDSN is an early participant of the global earth observation system of systems (GEOSS), contributing high-quality, timely and freely accessible seismic data. The purpose of this paper is to provide an overview of the FDSN from the viewpoint of an integrated system of observatories and to share with other GEOSS networks the successes, challenges and lessons learned by the FDSN in promoting the open and free access of seismological data for the benefit of scientific research and disaster prevention and mitigation.

Description: Glacier surfaces are known to harbour abundant and active microbial communities. Phosphorus has been shown to be deficient in glacial environments, and thus is one of the limits on microbial growth and activity. We quantified the phosphorus pool in cryoconite debris and the concentration of dissolved phosphorus in supraglacial water on Werenskioldbreen, a Svalbard glacier. The mean total P content of the cryoconite debris was similar to 2.2 mg g(-1), which is significantly more than would be expected in rock debris from local sources. 57% of this P was present in the fraction defined as organic P. It may account for the P in excess of the rock debris, and could be explained by allochthonous input of organic matter. The concentration of total dissolved P in supraglacial water was very low (5.2-8.5 mu g l(-1)), which was probably caused by efficient flushing and re-adsorption onto mineral surfaces. Dissolved organic P (DOP) was a very important component of the dissolved phosphorus pool on Werenskioldbreen, as concentrations of DOP typically exceeded those of dissolved inorganic P (or SRP) by more than four times in all the glacial water types. It is very difficult to assess whether P was limiting in this environment solely on the basis of the N:P ratios in the debris or biomass. There may be some degree of biological control over the C:N:P ratios in the debris, but the phosphorus cycling in the supraglacial environment on this glacier seems to be mainly controlled by physical and geochemical processes.

Description: In this study, we measure the interseismic deformation across the western Haiyuanfault. This fault is a major left-lateral fault at the north-eastern edge of the Tibetanplateau. Our aim is to better constrain its present mechanical behavior, at the originof two M ̃8 earthquakes in 1920 and 1927, and along which a seismic gap with highpotential seismic hazard has been identified. The gap is covered by ERS and Envisatdata along three adjacent tracks. Along the two easternmost tracks, a steep velocitygradient has been observed across the fault, consistent with a left-lateral slip at a rateof 6.3 ́s2 mm/yr below a small apparent locking depth (〈2 km), which may be in-dicative of transient superficial creep or related to a weak fault zone (Cavalié et al.2008). The western track has not yet been studied as it covers a very high mountain-ous area, which introduces strong geometrical decorrelation. In this study, we focuson this track and propose a new InSAR adaptive range filter algorithm. Generally, therange interferometric filter assumes a constant slope terrain and the new generation offilters, even if they shift bandwidth with respect to the terrain slope, perform a spectralcul for the whole range line. In our approach, a sliding moving window is used to per-form a local adaptive range filter. Areas over critical baseline and shadowed areas for example can be detected and masked with this approach. During the process, an op-timisation is performed to perfectly align the local common bandwidths. Preliminaryresults show an improvement of the coherence over mountainous area under study,making it possible to exploit the InSAR data archive in this area.

Description: In this study, we measure the interseismic deformation across the western Haiyuanfault. This fault is a major left-lateral fault at the north-eastern edge of the Tibetanplateau. Our aim is to better constrain its present mechanical behavior, at the originof two M ̃8 earthquakes in 1920 and 1927, and along which a seismic gap with highpotential seismic hazard has been identified. The gap is covered by ERS and Envisatdata along three adjacent tracks. Along the two easternmost tracks, a steep velocitygradient has been observed across the fault, consistent with a left-lateral slip at a rateof 6.3 ́s2 mm/yr below a small apparent locking depth (〈2 km), which may be in-dicative of transient superficial creep or related to a weak fault zone (Cavalié et al.2008). The western track has not yet been studied as it covers a very high mountain-ous area, which introduces strong geometrical decorrelation. In this study, we focuson this track and propose a new InSAR adaptive range filter algorithm. Generally, therange interferometric filter assumes a constant slope terrain and the new generation offilters, even if they shift bandwidth with respect to the terrain slope, perform a spectralcul for the whole range line. In our approach, a sliding moving window is used to per-form a local adaptive range filter. Areas over critical baseline and shadowed areas for example can be detected and masked with this approach. During the process, an op-timisation is performed to perfectly align the local common bandwidths. Preliminaryresults show an improvement of the coherence over mountainous area under study,making it possible to exploit the InSAR data archive in this area.

Description: Seismic monitoring in Romania has more than 100 years of tradition. In spite of the World wars and critical periods, these activities progressed and have a good future. Presently a complex and high dynamic range real time seismic network ensures the seismic monitoring in Romania. A huge seismic database became a strong support for research and investigation in seismic field of activity. This insures a constant seismic data exchange with the global seismic monitoring systems. International collaboration is established with important scientific entities around of the world. There is a planning for a future upgrade of the National Seismic Network with more broadband seismic stations. Infrasound research project, as complementary activity for Romanian seismic monitoring, will start also.

Description: Die Bundesregierung beauftragte die Helmholtz-Gemeinschaft, vertreten durch das GFZ, mit der Entwicklung eines Tsunami-Frühwarnsystems für den indischen Ozean. Seit dem 11. November ist das System offiziell im Betrieb. Projektleiter Jörn Lauterjung stellte sich den Fragen der „GeoForschungs-Zeitung“.

Description: Seismological studies generally suggest that the Earth’s inner core is anisotropic and the anisotropic structure changes significantly both laterally and with depth. Previous body-wave studies of the inner core have relied on ray tracing or waveform modeling using one-dimensional (1D) models. Here we present non-linear tomographic inversions of the inner core anisotropy using three-dimensional (3D) ray tracing, spline parameterization, and a large collection of PKP differential travel times. We adapt a pseudo-bending ray tracing (PBR) method in spherical coordinates for seismic rays that traverse the inner core (PKP(DF) phase). The method iteratively perturbs each discontinuity point and continuous segment of the ray through 3D earth structure so that its travel time is minimum. The 3D anisotropic structure of the inner core is approximated to the first order as 3D heterogeneous (but isotropic) structure for a given ray. The data are corrected using a scaled mantle tomographic model. The inner core anisotropy model obtained has the following major features. (1) The model has strong hemispherical and depth variation. The isotropic velocity in the topmost inner core is greater in quasi-eastern hemisphere (QEH) (40–160°E) than in quasi-western hemisphere (QWH) (other longitudes). The anisotropy is weak in QEH to the depth of 600–700 km below the inner core boundary (ICB), while in QWH, the anisotropy increases at much shallower depth (about 100–200 km below the ICB) to about 3–4%, then remains at about 2–4% throughout the rest of the inner core. (2) The anisotropy form changes abruptly (over a depth range of about 150 km) at the radius of about 600 km, slightly less than half of the inner core radius, forming a distinct inner inner core (IIC). The velocity in the IIC has maximums at equatorial and polar directions and minimum at an angle of about 40° from the equatorial plane. The velocity in the outer inner core (OIC), however, changes little for ray directions 0–40° from the equatorial plane. (3) Despite large variation of the anisotropy, the isotropic velocity (Voigt average) throughout the inner core is nearly uniform. The results suggest that the OIC is likely composed of the same type of iron crystals with uniform chemistry, but the IIC may be composed of a different type of crystal alignment, a different iron phase, or a different chemical composition. Our tests on model parameterization, mantle correction, and linear and non-linear inversion suggest the main features of our model are very robust. However, fine scale structures are likely to differ, particularly in the major transition zones, e.g., in the topmost QWH (isotropy to anisotropy), between OIC and IIC (change in the form of anisotropy), and between QEH and QWH in OIC (difference in anisotropy strength). Searches for possible waveform complications from these boundaries need to be aware of the directional dependence and geographical variation to be successful.

Description: Warum gleiten die Pazifische und die Nordamerikanische Platte in Mittelkalifornien einfach aneinander vorbei, während sie in den Ballungsgebieten von Los Angelos und San Francisco katastrophale Erdbeben verursachen? Um den Erdbeben auf den Grund zu gehen, errichteten Wissenschaftler der „Stanford Universität“ und des „US Geological Survey“ das San Andreas Tiefenobservatorium (SAFOD). Im Rahmen eines ICDP Projektes durchbohrten sie 2007 den Erdbebenherd in einer Tiefe von 2500 Meter. Parallel zu dieser Bohrung führte der GFZ-Mitarbeiter Michael Becken zusammen mit der Arbeitsgruppe Magnetotellurik großflächige geophysikalische Untersuchungen an der San Andreas Störung durch.

Description: Im Jahr 2016 soll er fertig gestellt sein: der Gotthard-Basistunnel. Mit 57 Kilometern wird er dann der längste und modernste Tunnel der Welt sein. Ein Projekt der Superlative. Grund genug für den Verein der „Freunde und Förderer des GFZ“ (FFGFZ), diesem Großprojekt auf einer Exkursion einen Besuch abzustatten. Am 22. Oktober konnten zwölf Mitglieder des Vereins die Arbeiten mit der Tunnelbohrmaschine der Firma Herrenknecht vor Ort erleben.

Description: Oceanic microseisms are small oscillations of the ground, in the frequency range of 0.05–0.3 Hz, associated with the occurrence of energetic ocean waves of half the corresponding frequency. In 1950, Longuet-Higgins suggested in a landmark theoretical paper that (i) microseisms originate from surface pressure oscillations caused by the interaction between oppositely travelling components with the same frequency in the ocean wave spectrum, (ii) these pressure oscillations generate seismic Stoneley waves on the ocean bottom, and (iii) when the ocean depth is comparable with the acoustic wavelength in water, compressibility must be considered. The efficiency of microseism generation thus depends on both the wave frequency and the depth of water. While the theory provided an estimate of the magnitude of the corresponding microseisms in a compressible ocean, its predictions of microseism amplitude heretofore have never been tested quantitatively. In this paper, we show a strong agreement between observed microseism and calculated amplitudes obtained by applying Longuet-Higgins' theory to hindcast ocean wave spectra from the North Atlantic Ocean. The calculated vertical displacements are compared with seismic data collected at stations in North America, Greenland, Iceland and Europe. This modelling identifies a particularly energetic source area stretching from the Labrador Sea to south of Iceland, where wind patterns are especially conducive to generating oppositely travelling waves of same period, and the ocean depth is favourable for efficient microseism generation through the ‘organ pipe’ resonance of the compression waves, as predicted by the theory. This correspondence between observations and the model predictions demonstrates that deep ocean nonlinear wave–wave interactions are sufficiently energetic to account for much of the observed seismic amplitudes in North America, Greenland and Iceland.

Description: Cryoconite holes are unique freshwater environments on glacier surfaces, formed when solar-heated dark debris melts down into the ice. Active photoautotrophic microorganisms are abundant within the holes and fix inorganic carbon due to the availability of liquid water and solar radiation. Cryoconite holes are potentially important sources of organic carbon to the glacial ecosystem, but the relative magnitudes of autochthonous microbial primary production and wind-borne allochthonous organic matter brought are unknown. Here, we compare an estimate of annual microbial primary production in 2006 on Werenskioldbreen, a Svalbard glacier, with the organic carbon content of cryoconite debris. There is a great disparity between annual primary production (4.3 mu g C g(-1) year(-1)) and the high content of organic carbon within the debris (1.7-4.5%, equivalent to 8500-22 000 mu g C g(-1) debris). Long-term accumulation of autochthonous organic matter is considered unlikely due to ablation dynamics and the surface hydrology of the glacier. Rather, it is more likely that the majority of the organic matter on Werenskioldbreen is allochthonous. Hence, although glacier surfaces can be a significant source of organic carbon for glacial environments on Svalbard, they may be reservoirs rather than oases of high productivity.

Description: Digitale Forschungsdaten sind sowohl unverzichtbare Basis als auch Resultat der wissenschaftlichen Arbeit. Jede Disziplin hat ihre eigenen technischen und inhaltlichen Ansprüche und Vorstellungen, so dass eine Vielfalt von Formate und Medientypen als Forschungsdaten vorkommen: von Meßdatentabellen im ASCII-Format bis hin zu interaktiven 3D-Modellen. Allen ist aber gemeinsam, dass sie eine wertvolle, jedoch schwierig zu managende Ressource darstellen. In diesem Vortrag werden Strategien vorgestellt und diskutiert, wie das Management von Forschungsdaten besser gestaltet und wissenschaftliche Arbeitsabläufe unterstützt werden können, ohne dabei eine "Datenmanagement-Bürokratie" aufzubauen.

Description: A temporal seismic network recorded local seismicity along a 130 km long segment of the transpressional dextral strike-slip Liquiñe-Ofqui fault zone (LOFZ) in southern Chile. Seventy five shallow crustal events with magnitudes up to M(tief)w 3.8 and depths shallower than 25 km were observed in an 11-month period mainly occurring in different clusters. Those clusters are spatially related to the LOFZ, to the volcanoes Chaitén, Michinmahuida and Corcovado, and to active faulting on secondary faults. Further activity along the LOFZ is indicated by individual events located in direct vicinity of the surface expression of the LOFZ. Focal mechanisms were calculated using deviatoric moment tensor inversion of body wave amplitude spectra which mostly yield strike-slip mechanisms indicating a NE–SW direction of the P-axis for the LOFZ at this latitude. The seismic activity reveals the present-day activity of the fault zone. The recent M(tief)w 6.2 event near Puerto Aysén, Southern Chile at 45.4°S on April 21, 2007 shows that the LOFZ is also capable of producing large magnitude earthquakes and therefore imposing significant seismic hazard to this region.

Description: Der Themenband vereinigt ausgewählte Forschungsergebnisse zum Risikomanagement extremer Hochwasserereignisse. In der vom BMBF initiierten Förderaktivität konnten neben herausragenden Hochwassern der letzten Jahrzehnte auch sehr seltene Abflussereignisse vor 1900 untersucht werden. Zunächst werden die vorrangig in Archiven lagernden wasserwirtschaftlich/wasserbaulich relevanten Altunterlagen sowie meteorologische und hydrologische Datensätze vorgestellt und geeignete Methoden zu deren Erhebung und kritischen Bewertung näher erläutert. Anschließend wird anhand von Fallbeispielen aufgezeigt, wie hinlänglich gesicherte historische Quellenbefunde erfolgreich in aktuelle Analysen integriert werden können. Hierzu gehören sowohl die Rekonstruktion hochwasserrelevanter Wetterlagen am Beispiel des Neckarhochwassers von 1824 als auch die hydraulische Modellierung historischer Hochwasserereignisse sowie statistische Analysen zur Häufigkeit schwerer Hochwasser der Elbe.

Description: The deep structure of the upper mantle is determined from data on phase velocities of Love and Rayleigh waves measured by a differential method on traces between two stations in central Western Europe. One-dimensional velocity structures are first constructed from data of each pair of stations, after which two-dimensional distributions of SH and SV velocities are calculated by the method of two-dimensional tomography from S wave velocities at fixed depths. The results are presented in the form of 2-D vertical structures of the average S wave velocity (S = (SV + SH)/2) constructed along profiles crossing the region in directions of the best resolution. The main structural features are a higher velocity zone at depths of 60–80 km in the area (48°–50°N, 9°–11°E) and a lower velocity zone in the western part of the region at depths of 100–150 km, probably extending farther beyond the studied area

Description: For derived flood frequency analysis based on hydrological modelling long continuous precipitation time series with high temporal resolution are needed. Often, the observation network with recording rainfall gauges is poor, especially regarding the limited length of the available rainfall time series. Stochastic precipitation synthesis is a good alternative either to extend or to regionalise rainfall series to provide adequate input for long-term rainfall-runoff modelling with subsequent estimation of design floods. Here, a new two step procedure for stochastic synthesis of continuous hourly space-time rainfall is proposed and tested for the extension of short observed precipitation time series. First, a single-site alternating renewal model is presented to simulate independent hourly precipitation time series for several locations. The alternating renewal model describes wet spell durations, dry spell durations and wet spell intensities using univariate frequency distributions separately for two seasons. The dependence between wet spell intensity and duration is accounted for by 2-copulas. For disaggregation of the wet spells into hourly intensities a predefined profile is used. In the second step a multi-site resampling procedure is applied on the synthetic point rainfall event series to reproduce the spatial dependence structure of rainfall. Resampling is carried out successively on all synthetic event series using simulated annealing with an objective function considering three bivariate spatial rainfall characteristics. In a case study synthetic precipitation is generated for some locations with short observation records in two mesoscale catchments of the Bode river basin located in northern Germany. The synthetic rainfall data are then applied for derived flood frequency analysis using the hydrological model HEC-HMS. The results show good performance in reproducing average and extreme rainfall characteristics as well as in reproducing observed flood frequencies. The presented model has the potential to be used for ungauged locations through regionalisation of the model parameters.

Description: In order to determine the links between geochemical parameters controlling the formation of silica sinter in hot springs and their associated microbial diversity, a detailed characterisation of the waters and of in situ-grown silica sinters was combined with molecular phylogenetic analyses of the bacteria] communities in Icelandic geothermal environments. At all but one site, the microorganisms clearly affected, and in part controlled, the formation of the macroscopic textures and structures of silica sinter edifices. In addition, the class and genera level phylogenetic diversity and distribution appeared to be closely linked to variations in temperature, salinity and pH regimes.

Description: A new model of the three-dimensional shear velocity structure of the Africa-Eurasia plate boundary is presented. The new model is derived by jointly inverting different types of seismic data. The two main sources of information are regional waveforms and teleseismic S wave arrival times. We show that it is possible to find a model that fit the different data types nearly as well as when inverting solely one type of data. The main improvement in resolving power is achieved between depths of 300 and 700 km, though the improvements are not limited to this depth range. Our model reflects the complicated evolution of this plate boundary area. The transition zone is dominated by high-velocity anomalies which we infer to represent a mix of lithosphere that subducted relatively recently or is not sufficiently cold and dense to traverse the 660-km discontinuity. The only low-velocity zone in the transition zone is beneath the Ionian Sea. The high-velocity Hellenic slab is continuous throughout the upper mantle and into the lower mantle to about 1200 km, most likely representing subducted Neo-Tethys lithosphere. The uppermost mantle is dominated by low velocities, consistent with the high level of tectonic activity. Low-velocity regions are relatively strong beneath the Mid-Atlantic Ridge, Turkey, and the Dead Sea region. The region's current lithosphere is relatively thin, except beneath the Adriatic and Ionian seas and the easternmost Atlantic Ocean.

Description: An extensive analysis of multiple ScS reverberation data sets sampling regions of active or recent subduction reveals evidence of midmantle reflections apparently stemming from fragments of subducted slabs or from the interaction between subducted slabs and the surrounding mantle. Transition zone reflectors are detected beneath the southwest Pacific Ocean and Melanesia with mean depths of ∼850 and 1100 km in the majority of source–receiver corridors crossing the study area. The observations are most spatially coherent beneath the Coral and Tasman Seas. Coincident observations of the two reflectors along most seismic corridors suggests (but does not mandate) the existence of two distinct reflectors rather than bimodal depth distribution of a single reflector or distributed scatterers. Beneath North America, reflectors at depths of ∼1380 and 1530 km are seen in the midcontinent region; further east, the reflections are shallower, with depths near 940 and 1130 km. Unlike the southwest Pacific, the reflectors are not paired in any of the individual source–receiver corridors. This and the depth variability of the observations indicate that the reflector (or reflectors) in the Americas is (are) fragmented from west to east (transecting source–receiver corridors). The impedance contrasts of these features rival that of the 660-km discontinuity, suggesting that individual fragments of the reflecting surfaces must be relatively continuous and flat from north to south (along individual corridors) to maintain a strong apparent impedance contrast. The reflections in both study areas are unlikely to be the result of slabs interacting with a chemical boundary layer or small-scale scatterers within the midmantle. More likely these reflectors result from a pressure–temperature-dependent phase transition within or around subducting slabs.

Description: Productivity in the Southern Oceans is iron-limited, and the supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine reservoir. Glacial sediment sources of iron have rarely been considered, as the iron has been assumed to be inert and non-bioavailable. This study demonstrates the presence of potentially bioavailable Fe as ferrihydrite and goethite in nanoparticulate clusters, in sediments collected from icebergs in the Southern Ocean and glaciers on the Antarctic landmass. Nanoparticles in ice can be transported by icebergs away from coastal regions in the Southern Ocean, enabling melting to release bioavailable Fe to the open ocean. The abundance of nanoparticulate iron has been measured by an ascorbate extraction. This data indicates that the fluxes of bioavailable iron supplied to the Southern Ocean from aeolian dust (0.01-0.13 Tg yr(-1)) and icebergs (0.06-0.12 Tg yr(-1)) are comparable. Increases in iceberg production thus have the capacity to increase productivity and this newly identified negative feedback may help to mitigate fossil fuel emissions.

Description: Presented here are quantitative dissolution rate data (Volume of pyrite lost/time) for the inorganic oxidation of pyrite in synthetic, anaerobic and acidic (pH 2) hydrothermal vent fluids (HVF) from experiments where the volume toss was measured directly via Vertical Scanning Interferometry (VSI). The VSI-derived reaction rate was 2.12 x 10(-10) +/- 1.14 x 10(-11) mol/m(2)/min, which is similar to 2 to 4 orders of magnitude slower than pyrite oxidation rates previously determined using traditional batch experiments where rates are calculated based on changes in Solution chemistry. This lower rate stems primarily from differences in experimental conditions (i.e. water to rock ratios, vigorous vs. gentle stir rates, grain-size effects, time), yet the rates derived here are believed to be more representative of pyrite oxidation in natural environments where more static and high solution to solid rate conditions prevail, such as seafloor conditions or acid-mine-drainage environments.

Description: Magnetotelluric (MT) data from 66 sites along a 45-km-long profile across the San Andreas Fault (SAF) were inverted to obtain the 2-D electrical resistivity structure of the crust near the San Andreas Fault Observatory at Depth (SAFOD). The most intriguing feature of the resistivity model is a steeply dipping upper crustal high-conductivity zone flanking the seismically defined SAF to the NE, that widens into the lower crust and appears to be connected to a broad conductivity anomaly in the upper mantle. Hypothesis tests of the inversion model suggest that upper and lower crustal and upper-mantle anomalies may be interconnected.We speculate that the high conductivities are caused by fluids and may represent a deep-rooted channel for crustal and/or mantle fluid ascent. Based on the chemical analysis of well waters, it was previously suggested that fluids can enter the brittle regime of the SAF system from the lower crust and mantle. At high pressures, these fluids can contribute to fault-weakening at seismogenic depths. These geochemical studies predicted the existence of a deep fluid source and a permeable pathway through the crust. Our resistivity model images a conductive pathway, which penetrates the entire crust, in agreement with the geochemical interpretation. However, the resistivity model also shows that the upper crustal branch of the high-conductivity zone is locatedNEof the seismically defined SAF, suggesting that the SAF does not itself act as a major fluid pathway. This interpretation is supported by both, the location of the upper crustal highconductivity zone and recent studies within the SAFOD main hole, which indicate that pore pressures within the core of the SAF zone are not anomalously high, that mantle-derived fluids are minor constituents to the fault-zone fluid composition and that both the volume of mantle fluids and the fluid pressure increase to the NE of the SAF.We further infer from the MT model that the resistive Salinian block basement to the SW of the SAFOD represents an isolated body, being 5–8 km wide and reaching to depths 〉7 km, in agreement with aeromagnetic data. This body is separated from a massive block of Salinian crust farther to the SW. The NE terminus of resistive Salinian crust has a spatial relationship with a near-vertical zone of increased seismic reflectivity ∼15 km SW of the SAF and likely represents a deep-reaching fault zone.

Description: A new three-dimensional seismic model and relocated regional seismicity are used to illuminate the great Sumatra-Andaman Islands earthquake of December 26, 2004. The earthquake initiated where the incoming Indian Plate lithosphere is warmest and the dip of the Wadati-Benioff zone is least steep along the subduction zone extending from the Andaman Trench to the Java Trench. Anomalously high temperatures are observed in the supra-slab mantle wedge in the Andaman back-arc. The subducting slab is observed along the entire plate boundary to a depth of at least 200 km. These factors contribute to the location of the initiation of rupture, the strength of seismic coupling, the differential rupture properties between the northern and southern segments of the earthquake, and the cause of convergence in the Andaman segment.

Description: The reduction of information contained in model time series through the use of aggregating statistical measures is very high compared to the amount of information that one would like to draw from it for model identification and calibration purposes. Applied within a model identification context, aggregating statistical performance measures are inadequate to capture details on time series characteristics. It has been readily shown that this loss of information on the residuals imposes important limitations on model identification and -diagnostics and thus constitutes an element of the overall model uncertainty. In this contribution we present an approach using a Self-Organizing Map (SOM) to circumvent the identifiability problem induced by the low discriminatory power of aggregating performance measures. Instead, a Self-Organizing Map is used to differentiate the spectrum of model realizations, obtained from Monte-Carlo simulations with a distributed conceptual watershed model, based on the recognition of different patterns in time series. Further, the SOM is used instead of a classical optimization algorithm to identify the model realizations among the Monte-Carlo simulations that most closely approximate the pattern of the measured discharge time series. The results are analyzed and compared with the manually calibrated model as well as with the results of the Shuffled Complex Evolution algorithm (SCE-UA).

Description: Global mapping of 410 and 660 km discontinuity topography and transition zone thickness has proven to be a powerful tool for constraining mantle chemistry, dynamics and mineralogy. Numerous seismic and mineral physics studies suggest that the 410 km discontinuity results from the phase change of olivine to wadsleyite and the 660 km discontinuity results from the phase change of ringwoodite to perovskite and magnesiowustite. Underside reflections of the 410 and 660 km discontinuities arrive as precursors to SS. With the recent development of a semi-automated method of determining SS arrivals, we have more than tripled the Flanagan and Shearer (1998a) data set of handpicked SS waveforms. We are able to increase resolution by stacking waveforms in 5° rather than 10° radius bins as well as increasing data coverage significantly in the southern hemisphere. The resulting SS-S410S and SS-S660S times are heavily influenced by upper-mantle velocity structure. We perform a joint inversion for discontinuity topography and velocity heterogeneity as well as performing a simple velocity correction to the precursor differential times and find little difference between the two methods. The 660 km discontinuity topography and transition zone thickness are correlated with velocities in the transition zone whereas the 410 km discontinuity topography is not. In addition, the 410 km discontinuity topography is not correlated with the 660 km discontinuity topography, rather anticorrelated, as expected due to the opposite signs of the Clapeyron slopes of their respective phase changes. These results suggest that, whereas the topography of 660 km discontinuity could be dominated by thermal effects, the topography of the 410 km discontinuity is likely dominated by compositional effects. In addition, unlike previous studies which find less topography on the 410 km discontinuity than on the 660 km discontinuity, our 410 and 660 km topography have similar amplitudes.

Description: The nucleation and growth of silica nanoparticles in supersaturated geothermal waters was simulated using a flow-through geothermal simulator system. The effect of silica concentration ([SiO2]), ionic strength (IS), temperature (T) and organic additives on the size and polydispersity of the forming silica nanoparticles was quantified. A decrease in temperature (58 to 33 degrees C) and the addition of glucose restricted particle growth to sizes 〈20 mm, while varying [SiO2] or IS did not affect the size (30-35 nm) and polydispersity (+/- 9 nm) observed at 58 degrees C. Conversely, the addition of xanthan gum induced the development of thin films that enhanced silica aggregation.

Description: In this report, we will present the complete derivation of analytical expressions of the EM coupling torque in dependence on the parameters of the fields contributing to it. For this, we choose a special set of spherically harmonic (SH) base functions and present all major steps of the derivation. Our report will be (i) closer to a lecture note than to a scientific paper and should give all readers the possibility to follow the derivations with the related details in the appendix, and can be (ii) used as a formulary for scientists working on this special field of investigation.

Description: Field in-situ sinter growth studies have been carried out in five geochemically very different Icelandic geothermal areas with the aim to quantify the effects of water chemistry, (e.g. silica content (250 to 695 p.p.m. SiO(2)), salinity (meteoric to seawater), pH (7.5 to 10)), temperature (42-96 degrees C) and microbial abundance (prevalence, density) on the growth rates, textures and structures of sinters forming within and around geothermal waters. At each location, sinter growth was monitored over time periods between 30 min and 25 months using glass slides that acted as precipitation substrates from which sinter growth rates were derived. In geothermal areas like Svartsengi and Reykjanes, subaqueous sinters developed rapidly with growth rates of 10 and 304 kg year(-1) m(-2), respectively, and this was attributed primarily to the near neutral pH, high salinity and medium to high silica content within these geothermal waters. The porous and homogeneous precipitates that formed at these sites were dominated by aggregates of amorphous silica and they contained few if any microorganisms. At Hveragerdi and Geysir, the geothermal waters were characterized by slightly alkaline pH, low salinity and moderate silica contents, resulting in substantially lower rates of sinter growth (0.2-1.4 kg year(-1) m(-2)). At these sites sinter formation was restricted to the vicinity of the air-water interface (AWI) where evaporation and condensation processes predominated, with sinter textures being governed by the formation of dense and heterogeneous crusts with well-defined spicules and silica terraces. In contrast, the subaqueous sinters at these sites were characterized by extensive biofilms, which, with time, became fully silicified and thus well preserved within the sinter edifices. Finally, at Krafla, the geothermal waters exhibited high sinter growth rates (19.5 kg year(-1) m(-2)) despite being considerably undersaturated with respect to amorphous silica. However, the bulk of the sinter textures and structure were made up of thick silicified biofilms and this indicated that silica precipitation, i.e. sinter growth, was aided by the surfaces provided by the thick biofilms. These results further suggest that the interplay between purely abiotic processes and the ubiquitous presence of mesophilic and thermophilic microorganisms in modern silica rich terrestrial hydrothermal settings provides an excellent analogue for processes in Earth's and possibly Mars's ancient past.

Description: Results from a study of the chemical composition and micro-structural characteristics of bacterial magnetosomes extracted from the magnetotactic bacterial strain Magnetospirillum gryphiswaldense are presented here. Using high-resolution transmission electron microscopy combined with selected-area electron diffraction and energy dispersive X-ray microanalysis, biogenic magnetite particles isolated from mature cultures were analysed for variations in crystallinity and particle size, as welt as chain character and length. The analysed crystals showed a narrow size range (similar to 14-67 nm) with an average diameter of 46 +/- 6.8 nm, cuboctahedral morphologies and typical Gamma type crystal size distributions. The magnetite particles exhibited a high chemical purity (exclusively Fe3O4) and the majority fall within the single-magnetic-domain range.

Description: Tectonics of the eastern Mediterranean are strongly influenced by subduction of oceanic lithosphere with slab pull as a prominent driving force. The current distribution of remnants of oceanic lithosphere and the properties of African mantle lithosphere beneath the eastern Mediterranean basin have been a matter of debate. Previous studies variously found continental as well as oceanic lithosphere in this region. A set of 1-D S-wave velocity models is determined in order to characterize the mantle lithosphere in the area between Crete and the Middle East. For seven paths starting from Cyprus and running to Crete, to Anatolia as well as to the Middle East, broad-band average phase velocity curves of the fundamental Rayleigh mode are obtained in the frequency range of about 3 mHz to 90 mHz by a two-station method. In addition, an east–west oriented path crossing southern Anatolia and a path running parallel to the Dead Sea Fault Zone are considered. Phase velocity curves are inverted for path average 1-D S-wave velocity models. Resolution is investigated with the Neighbourhood Algorithm. Comparing the resulting 1-D models, cold oceanic mantle lithosphere showing S-wave velocities above 4.6 km s− 1 can be distinguished from mantle lithosphere with low S-wave velocities. Oceanic lithosphere is found west of Cyprus beneath the Herodotus basin. As indicated by Benioff zones, it is subducting towards northwest in the southeastern Aegean and towards northeast beneath southwestern Anatolia. To the east of Cyprus the mantle lithosphere beneath the easternmost Mediterranean Sea shows low S-wave velocities. No indications for cold oceanic mantle lithosphere are found beneath the Levant basin. In the region of the Dead Sea Fault Zone and the Levant basin the lithosphere–asthenosphere boundary is located at shallow depths of about 60 km to 80 km. The DSFZ is situated in a region of thinned lithosphere underlain by an asthenosphere with anomalous low S-wave velocities. Low S-wave velocities beneath southern Anatolia extend down to at least 150 km depth as expected for a back arc setting. Inferred Moho depths vary for the different paths between 28 km and 41 km

Description: The Vrancea region, in the South-Eastern Carpathians (Romania), represents a unique case among the seismic areas in the world taking into account the extreme concentration and persistence of seismicity and tectonic stress field. Our goal is to show that the particular shape of attenuation and shear wave splitting properties can be interpreted in the light of the decoupling and slab retreat processes, which hypothetically induce a specific configuration of the upper mantle flow. Delamination and break-off processes combined with retrograde motion of the slab imply lateral asymmetry in flow geometry and geotectonic properties. Particularly relevant is the strike-parallel flow localized in front of the downgoing slab, in contrast with the steeply dip flow along the slab in the back side. The local upper mantle flows around the descending seismic active body explains the contrast of the seismic wave attenuation in the back-arc region against fore-arc region and the strong anisotropy anomaly observed in the South-East Carpathians (time delays of 1.5–2 s). Outside the epicentral area, the coherent pattern of the shear wave splitting follows the trends of the deformation field as outlined by the GPS measurements, in favour of a strong coupling between the surface and mantle processes.

Description: A model of upper-mantle S-wave velocity and transverse anisotropy beneath northwestern Europe is presented, based on regional surface wave observations. Group velocities for both Love and Rayleigh surface waves are measured on waveform data from international and regional data archives (including temporary deployments) and then inverted for group velocity maps, using a method accounting for Fresnel zone sensitivity. The group velocity variations are larger than in global reference maps, and we are able to resolve unprecedented details. We then apply a linear inversion scheme to invert for local 1-D shear wave velocity profiles which are consequently assembled to a 3-D model. By choosing conservative regularization parameters in the 2-D inversion, we ensure the smoothness of the group velocity maps and hence of the resulting 3-D shear wave speed model. To account for the different tectonic regimes in the study region and investigate the sensitivity of the 1-D inversions to inaccuracies in crustal parameters, we analyse inversions with different reference models of increasing complexity (pure 1-D, 3-D crust/1-D mantle and pure 3-D). We find that all inverted models are very consistent at depths below 70 km. At shallower depths, the constraints put by the reference models, primarily Moho depth which we do not invert for, remain the main cause for uncertainty in our inversion. The final 3-D model shows large variations in S-wave velocity of up to ±12 per cent. We image an intriguing low-velocity anomaly in the depth range 70–150 km that extends from the Iceland plume beneath the North Atlantic and in a more than 400 km wide channel under Southern Scandinavia. Beneath Southern Norway, the negative perturbations are around 10 per cent with respect to ak135, and a shallowing of the anomaly is indicated which could be related to the sustained uplift of Southern Scandinavia in Neogene times. Furthermore, our upper-mantle model reveals good alignment to ancient plate boundaries and first-order crustal fronts around the triple junction of the Baltica-Avalonia–Laurentia collision in the North Sea.

Description: We propose a new rapid procedure for determining the energy magnitude Me for shallow events from broadband teleseismic P-wave signals within the distance range 20°–98°. To accomplish this task, we compute spectral amplitude decay functions for different periods using numerical simulations based on the reference Earth model AK135Q. By means of these functions, we correct the spectra of the teleseismic recordings for the propagation path effects, and calculate the radiated seismic energy ES, and hence Me. We use cumulative P-wave windows for simulating a real- or near real-time procedure and test it for 61 shallow earthquakes. The results show that our approach is able to provide a rapid and reliable Me determination within 7–15 minutes after the earthquake origin time, and is therefore suitable for implementation in rapid response systems.

Description: We apply the Automated Multimode Inversion of surface and S-wave forms to a large global data set, verify the accuracy of the method and assumptions behind it, and compute an Sv-velocity model of the upper mantle (crust–660 km). The model is constrained with ∼51 000 seismograms recorded at 368 permanent and temporary broadband seismic stations. Structure of the mantle and crust is constrained by waveform information both from the fundamental-mode Rayleigh waves (periods from 20 to 400 s) and from S and multiple S waves (higher modes). In order to enhance the validity of the path-average approximation, we implement the automated inversion of surface- and S-wave forms with a three-dimensional (3-D) reference model. Linear equations obtained from the processing of all the seismograms of the data set are inverted for seismic velocity variations also relative to a 3-D reference, in this study composed of a 3-D model of the crust and a one-dimensional (1-D), global-average depth profile in the mantle below. Waveform information is related to shear- and compressional-velocity structure within approximate waveform sensitivity areas. We use two global triangular grids of knots with approximately equal interknot spacing within each: a finely spaced grid for integration over sensitivity areas and a rougher-spaced one for the model parametrization. For the tomographic inversion we use LSQR with horizontal and vertical smoothing and norm damping. We invert for isotropic variations in S- and P-wave velocities but also allow for S-wave azimuthal anisotropy—in order to minimize errors due to possible mapping of anisotropy into isotropic heterogeneity. The lateral resolution of the resulting isotropic upper-mantle images is a few hundred kilometres, varying with data sampling. We validate the imaging technique with a ‘spectral-element’ resolution test: inverting a published global synthetic data set computed with the spectral-element method using a laterally heterogeneous mantle model we are able to reconstruct the synthetic model accurately. This test confirms both the accuracy of the implementation of the method and the validity of the JWKB and path-average approximations as applied in it. Reviewing the tomographic model, we observe that low-Sv-velocity anomalies beneath mid-ocean ridges and backarc basins extend down to ∼100 km depth only, shallower than according to some previous tomographic models; this presents a close match to published estimates of primary melt production depth ranges there. In the seismic lithosphere beneath cratons, unambiguous high velocity anomalies extend to ∼200 km. Pronounced low-velocity zones beneath cratonic lithosphere are rare; where present (South America; Tanzania) they are neighboured by volcanic areas near cratonic boundaries. The images of these low-velocity zones may indicate hot material—possibly of mantle-plume origin—trapped or spreading beneath the thick cratonic lithosphere.

Description: Urstromtäler, Grundmoränen und bewaldete Endmoränen markieren im äußersten Nordosten Brandenburgs die ehemalige Eisrandlage der letzten großen Inlandsvereisung. In der Weichseleiszeit vor rund 15.000 Jahren schufen hier Gletschereis, Schmelzwasser und Wind eine Fülle von charakteristischen Landschaftsformen, die sich im nationalen Geopark „Eiszeitland am Oderrand“ zeigen als wären sie erst gestern geschaffen worden.

Description: Complete protection against flood risks by structural measures is impossible. Therefore flood prediction is important for flood risk management. Good explanatory power of flood models requires a meaningful representation of bio-physical processes. Therefore great interest exists to improve the process representation. Progress in hydrological process understanding is achieved through a learning cycle including critical assessment of an existing model for a given catchment as a first step. The assessment will highlight deficiencies of the model, from which useful additional data requirements are derived, giving a guideline for new measurements. These new measurements may in turn lead to improved process concepts. The improved process concepts are finally summarized in an updated hydrological model. In this thesis I demonstrate such a learning cycle, focusing on the advancement of model evaluation methods and more cost effective measurements. For a successful model evaluation, I propose that three questions should be answered: 1) when is a model reproducing observations in a satisfactory way? 2) If model results deviate, of what nature is the difference? And 3) what are most likely the relevant model components affecting these differences? To answer the first two questions, I developed a new method to assess the temporal dynamics of model performance (or TIGER - TIme series of Grouped Errors). This method is powerful in highlighting recurrent patterns of insufficient model behaviour for long simulation periods. I answered the third question with the analysis of the temporal dynamics of parameter sensitivity (TEDPAS). For calculating TEDPAS, an ef- ficient method for sensitivity analysis is necessary. I used such an efficient method called Fourier Amplitude Sensitivity Test, which has a smart sampling scheme. Combining the two methods TIGER and TEDPAS provided a powerful tool for model assessment. With WaSiM-ETH applied to the Weisseritz catchment as a case study, I found insufficient process descriptions for the snow dynamics and for the recession during dry periods in late summer and fall. Focusing on snow dynamics, reasons for poor model performance can either be a poor representation of snow processes in the model, or poor data on snow cover, or both. To obtain an improved data set on snow cover, time series of snow height and temperatures were collected with a cost efficient method based on temperature measurements on multiple levels at each location. An algorithm was developed to simultaneously estimate snow height and cold content from these measurements. Both, snow height and cold content are relevant quantities for spring flood forecasting. Spatial variability was observed at the local and the catchment scale with an adjusted sampling design. At the local scale, samples were collected on two perpendicular transects of 60 m length and analysed with geostatistical methods. The range determined from fitted theoretical variograms was within the range of the sampling design for 80% of the plots. No patterns were found, that would explain the random variability and spatial correlation at the local scale. At the watershed scale, locations of the extensive field campaign were selected according to a stratified sample design to capture the combined effects of elevation, aspect and land use. The snow height is mainly affected by the plot elevation. The expected influence of aspect and land use was not observed. To better understand the deficiencies of the snow module in WaSiM-ETH, the same approach, a simple degree day model was checked for its capability to reproduce the data. The degree day model was capable to explain the temporal variability for plots with a continuous snow pack over the entire snow season, if parameters were estimated for single plots. However, processes described in the simple model are not sufficient to represent multiple accumulation-melt-cycles, as observed for the lower catchment. Thus, the combined spatio- 10 temporal variability at the watershed scale is not captured by the model. Further tests on improved concepts for the representation of snow dynamics at the Weißeritz are required. From the data I suggest to include at least rain on snow and redistribution by wind as additional processes to better describe spatio-temporal variability. Alternatively an energy balance snow model could be tested. Overall, the proposed learning cycle is a useful framework for targeted model improvement. The advanced model diagnostics is valuable to identify model deficiencies and to guide field measurements. The additional data collected throughout this work helps to get a deepened understanding of the processes in the Weisseritz catchment.

Description: The main aim of this study is to create a data set of accurate absolute arrival times for stations in Europe which do not report to the International Seismological Centre (ISC). Waveforms were obtained from data centres and temporary experiments and a semi-automatic picking method was applied to determine absolute arrival times for P and S phases. 85 000 arrival times were picked whose distribution of residuals shows generally low standard deviations on the order of 0.5–0.7 s. Furthermore, mean teleseismic station residuals reflect the properties of the underlying crust and uppermost mantle. Comparison to ISC data for matching event-station-phase combinations also confirms the good quality of the new absolute arrival time picks. Most importantly, this data set complements the ISC data as it fills regional data coverage gaps in Europe.

Description: The Kandilli Observatory Real-Time Automated Seismic Data Processing System (KORTASDPS) has been one of the most important infrastructure developments in the last 5 years at Kandilli Observatory and Earthquake Research Institute (KOERI), Boğaziçi University. KORTASDPS uses the Earthworm (EW) software suite for its real-time processing of seismic data. Primary functions of EW are to serve as real-time data server and auto-detect and locate earthquakes. Performance evaluation of EW was done by comparing its hypocenter catalogs from years 2004 and 2005 with catalogs produced by the National Earthquake Monitoring Center (NEMC) at KOERI which relies on manual detection and location techniques. In general EW performance is highest in northwest Turkey where station density and relative station sensitivity are high. Catalog correlations reveal that this area has an estimated 3.1 low magnitude threshold for a 90% earthquake auto-detection and location reliability. For the rest of the country this low magnitude threshold estimate ranges between 4.4 and 4.6. Three initiatives have been proposed to improve EW auto-detection and location accuracy. These are more accurate timing of emergent phases, use of reliable S phases and an increase in the effective seismic network density with more sensitive and reliable stations. Already expansion and modernization of KOERI’s seismic network in 2004 and 2005 have resulted in clear improvements in EW’s auto-detection and location performance. A one month pilot analysis was undertaken to understand the nature of the consistent large numbers of EW cataloged seismic events that do not correlate with NEMC. Results show that after careful manual relocation of these events that the majority are not found in either NEMC’s preliminary or final catalog and that these events represent almost one third of all events found in the combined EW and NEMC catalogs. Since 2003 the KOERI re-designed digital broadband network has increased from 4 to 33 stations and international shared broadband stations from 2 to 10. The past and planned increases of more sensitive and higher quality seismic stations has and will continue to improve the performance of EW’s auto-detection and location reliability and provide a source of information rich data to be used for ongoing and future seismological research activities.

Description: We propose a method of waveform inversion to rapidly and routinely estimate both the moment function and the centroid moment tensor (CMT) of an earthquake. In this method, waveform inversion is carried out in the frequency domain to obtain the moment function more rapidly than when solved in the time domain. We assume a pure double-couple source mechanism in order to stabilize the solution when using data from a small number of seismic stations. The fault and slip orientations are estimated by a grid search with respect to the strike, dip and rake angles. The moment function in the time domain is obtained from the inverse Fourier transform of the frequency components determined by the inversion. Since observed waveforms used for the inversion are limited in a particular frequency band, the estimated moment function is a bandpassed form. We develop a practical approach to estimate the deconvolved form of the moment function, from which we can reconstruct detailed rupture history and the seismic moment. The source location is determined by a spatial grid search using adaptive grid spacings, which are gradually decreased in each step of the search. We apply this method to two events that occurred in Indonesia by using data from a broad-band seismic network in Indonesia (JISNET): one northeast of Sulawesi (Mw = 7.5) on 2007 January 21, and the other south of Java (Mw = 7.5) on 2006 July 17. The source centroid locations and mechanisms we estimated for both events are consistent with those determined by the Global CMT Project and the National Earthquake Information Center of the U.S. Geological Survey. The estimated rupture duration of the Sulawesi event is 16 s, which is comparable to a typical duration for earthquakes of this magnitude, while that of the Java event is anomalously long (176 s), suggesting that this event was a tsunami earthquake. Our application demonstrates that this inversion method has great potential for rapid and routine estimations of both the CMT and the moment function, and may be useful for identification of tsunami earthquakes.

Description: The lithospheric structure of the Aegean region is investigated by analysis of Rayleigh-wave fundamental mode dispersion measurements. Isotropic 1-D models for almost 100 two-station ray paths across the region display distinct variations in the Moho depth and crustal S-wave velocities. The descending slab of the subducting African plate can be resolved down to 120 km depth beneath the volcanic arc. Three different regions are distinguished in terms of Moho depth: (1) The forearc, with large crustal thicknesses between 38 and 48 km and an average of 43 km, (2) the northern Aegean, with an average Moho depth of 28 km and (3) the southern Aegean (central volcanic arc, i.e. Cyclades, and Sea of Crete) with an even thinner crust of around 25 km. Lateral variations in structure between 25 and 55 km depth indicate a marked difference between the western and eastern forearc, collocated with pronounced changes in trench and slab geometry as well as published deformation rates. S velocities between 25 and 55 km depth are low everywhere beneath the forearc but increase from the Peleponnesus to Crete. An abrupt change occurs between western and central Crete in terms of the visibility of the Aegean Moho and the seismic structure of the lithospheric mantle wedge: An Aegean mantle wedge with S velocities above 4.4 km s−1 is only observed to the east of central Crete, whereas to the west velocities of less than 4.0 km s−1 occur down to the plate contact. These low velocities above the slab may indicate the presence of a melange of metamorphic rocks at the depths. A low-velocity asthenospheric layer is observed beneath the Sea of Crete and the Cyclades below 40 km depth, between the thinned lithosphere above and the slab below. The observed radial anisotropy in the northern part of the Aegean is likely to be due to preferred orientation of anisotropic minerals within the lower crust, possibly caused by lateral ductile flow associated with recent lithospheric extension.

Description: Sowohl für die Hochwasservorsorge als auch generell für den Hochwasserschutz, ist eine verlässliche Gefährdungsabschätzung notwendig. Diese basiert in der Regel auf der statistischen Analyse belastbarer Durchflusszeitreihen an Pegeln. Ein Grundanliegen des in der RIMAX-Initiative geförderten Projektes „Integration von historischen und hydraulisch/hydrologischen Analysen zur Verbesserung der regionalen Gefährdungsabschätzung und zur Erhöhung des Hochwasserbewusstseins“, bestand in der Überprüfung und Erweiterung der Datenbasis des historisch gut dokumentierten Elbepegels Dresden. Es zeigt sich, dass die interdisziplinäre Auswertung historischer Dokumente eine gute Basis darstellt, die Zuverlässigkeit der Durchflusszeitreihen zu erhöhen und sie auch über die bestehenden Reihenlängen hinaus zu erweitern.

Description: In this paper, the kinetics of Mo and V (100 mu M) uptake oil ferrihydrite (FHY) were evaluated in batch. mono-sorbate systems at pH between 4 and 9, and in bi-sorbate systems in the presence of P (100 mu M) at pH 7. In the Mo and V single-sorbate experiments, 100% adsorption was observed at pH values below 6 and 9, respectively. Above the point of zero charge (PZC = 7.97) of FHY, the adsorption efficiency for Mo dropped dramatically (20% at pH 8) while V showed high uptake efficiencies even at pH 9 (60% efficiency). The results from the bi-sorbate experiments (Mo-P and V-P) showed that at pH 71 P out-competed (97%) Mo for binding sites on FHY, while in the V-P binary system only similar to 44% of the binding sites are occupied by P with the remaining sites being occupied by V.

Description: The Romanian Seismic Network consisting of 8 short-period stations (S13), 60 Altus — K2 and Q330 seismic stations, is primarily designed to survey the Vrancea seismic region (strong and moderate Vrancea earthquakes). Since July 2002, a new seismic monitoring system, Bucovina Seismic Array (BURAR) has been operating. BURAR consists of 12 seismic stations distributed on a 5 km × 5 km area. 9 stations are equipped with short-period (SP) vertical sensors (GS-21 res) and one station is equipped with broad-band (BB) three component sensor (KS 54000). Broad-band sensors GMG40T (1000V/cm/s) were installed at 5 of the short-period stations, at the beginning of 2008. Recently, NIEP has developed its real-time digital seismic network. This network consists of 21 broad band stations and one seismic array. In the next year NIEP will install additional broad band stations in the central part of Romanian territory and other 40 strong motions stations in Bucharest.At the National Data Centre (NDC) runs BRTT’s Antelope™ 4.9 data acquisition and processing software on two HP workstations for real-time and post processing. The Antelope Real-Time System is also providing automatic event detection, arrival picking, event location and magnitude calculation.The Romanian Seismic Network is already linked with IRIS and ORFEUS organizations and other European countries via Internet and is contributing in near real time with waveform data from 5 broadband stations.The seismotectonic characteristics of the Vrancea region offer the opportunity to create and develop a rapid seismic warning system. This system allows warning in an approximately 25 seconds time window for Bucharest.

Description: Ice-hosted sediments in glaciers and icebergs from Antarctica and Svalbard contain authigenic nano particulates of schwertmannite, ferrihydrite and goethite that formed during sulphide oxidation. These phases indicate the existence of subglacial biogeochemical hotspots containing fluids of low pH (2-4), rich in dissolved Fe(III) and sulphate. Nanophase Fe is partially bioavailable and potentially important to global biogeochemical cycles, since the flux delivered by icebergs to the Southern Ocean is comparable to the flux of soluble, bioavailable Fe from aeolian dust.

Description: 23.000 Tote und 250.000 Obdachlose: das ist die Bilanz von Naturkatastrophen der letzten fünfzig Jahre in Zentralasien. Um Erdbebenrisiken in Zukunft besser abzuschätzen, reiste im August ein Team um den Geophysiker Stefano Parolai im Rahmen des Projektes „Mikrozonierung“ nach Bischkek, der Hauptstadt Kirgisistans. In Zusammenarbeit mit dem „Zentralasiatischen Institut für Angewandte Geowissenschaften“ (ZAIAG) untersuchten die Forscher den Untergrund des Stadtgebietes, um Bodenbewegungen im Erdbebenfall besser vorhersagen zu können.

Description: The Mediterranean Network (MedNet) presently comprises 22 operating broadband seismic stations installed and maintained in cooperation with 13 geophysical institutions in Italy and in most of the countries adjacent to the Mediterranean Sea. The number of stations may vary as stations are opened or sometimes closed due to different reasons like political, technical, etc., but usually temporarily. All the stations are equipped with Quanterra digitizers and Streckeisen sensors, mostly STS2 with a few STS1. Aim of the network is to contribute to monitoring of one of the most active seismic regions of the World in terms of providing high quality real-time broadband data to the seismological community. Operations started with off-line field data collection and dial-up capabilities were later added at selected sites. At present these have been replaced with more efficient TCP connections that provide for real-time data collection over the whole network. This important technological upgrade allows a prompt contribution to the seismic monitoring of Italy and of most countries bordering the Mediterranean Sea, since data are exchanged in real-time with other seismological observatories. SeedLink protocol has been adopted for data transmission. As for data archiving and distribution, a fast system for retrieving data has been developed. Continuous data streams, collected both from field data tapes and from real-time transfer, are stored at the MedNet Data Center and are directly available at users’ request by the standard AutoDRM and NetDC protocols (in GSE and SEED formats respectively). Station metadata and continuous waveforms are archived in a MySQL database on RAID systems and backed up on DLT tapes. Presently, fully automatic network functions include: daily monitoring of state of health; triggered retrieval of event waveforms (with magnitude- and region-specific selection criteria), local and surface wave magnitude determination, and update of web pages (http://mednet.ingv.it) for events and station information. Rapid semiautomatic moment tensor solutions are calculated by means of a modified Harvard technique, which lowers the Mw threshold down to 4.5 for regional events in those areas with proper station coverage. For smaller earthquakes in Italy a new approach to moment tensor estimation, based on higher signal frequencies, is now being developed. Preliminary tests on earthquake recordings (not only MedNet stations) from the 2002 Molise, South Italy, sequence have proved very successful.

Description: Im Hochwassermanagement werden hydrodynamisch-numerische Modelle mit unterschiedlicher Dimensionalität für die Ermittlung von Überflutungsflächen, Auswirkungen von Hochwasserschutzmaßnahmen und Veränderungen im zeitlichen Verlauf von Hochwasserganglinien erfolgreich eingesetzt. Dieser Artikel hat die Quantifizierung der Unsicherheiten in den Ergebnissen der hydrodynamisch-numerischen Modellierung zum Inhalt. Die Genauigkeit von Simulationsergebnissen ist abhängig von dem verwendeten Modellierungsansatz, dessen numerischer Methode, der Auflösung des digitalen Geländemodells sowie der Unsicherheit verschiedener Eingangsparameter. Die Analyse der Unsicherheiten erfolgt über einen Ergebnisvergleich zwischen dem zweidimensionalen Modell Hydro_AS-2D und dem rasterbasierten hybriden Modell SOBEK-Rural sowie über die Bestimmung des Einflusses von unterschiedlichen DGM-Auflösungen auf die Simulationsergebnisse von Hydro_AS-2D. Bezüglich der Parameterunsicherheit werden im Rahmen einer Parameterstudie mit SOBEK-Rural die Einflüsse der Eingangsparameter Rauheit, Geländehöhe und Abfluss (Randbedingungen) mittels einer Monte-Carlo-Simulation und einer generalisierten Sensitivitätsanalyse (GSA) untersucht.