Seismic loss estimation tool as rapid survey for prioritizing buildings for disaster preparedness: case study to hospital buildings

Natural Hazards - Hospital buildings must be fully operational after the earthquake to protect the lives of patients as well as to provide emergency care and medical treatment to the victims....     

Real-time envelope cross-correlation detector: application to induced seismicity in the Insheim and Landau deep geothermal reservoirs

We develop and test a real-time envelope cross-correlation detector for use in seismic response plans to mitigate hazard of induced seismicity. The incoming seismological data are cross-correlated in real-time with a set of previously recorded master events. For robustness against small changes in the earthquake source locations or in the focal mechanisms we cross-correlate the envelopes of the seismograms rather than the seismograms themselves. Two sequenced detection conditions are implemented: After passing a single trace cross-correlation condition, a network cross-correlation is calculated taking amplitude ratios between stations into account. Besides detecting the earthquake and assigning it to the respective reservoir, real-time magnitudes are important for seismic response plans. We estimate the magnitudes of induced microseismicity using the relative amplitudes between master event and detected event. The real-time detector is implemented as a SeisComP3 module. We carry out offline and online performance tests using seismic monitoring data of the Insheim and Landau geothermal power plants (Upper Rhine Graben, Germany), also including blasts from a nearby quarry. The comparison of the automatic real-time catalogue with a manually processed catalogue shows, that with the implemented parameters events are always correctly assigned to the respective reservoir (4 km distance between reservoirs) or the quarry (8 km and 10 km distance, respectively, from the reservoirs). The real-time catalogue achieves a magnitude of completeness around 0.0. Four per cent of the events assigned to the Insheim reservoir and zero per cent of the Landau events are misdetections. All wrong detections are local tectonic events, whereas none are caused by seismic noise.     

Toxicity studies of elemental sulfur in marine sediments

Elemental sulfur(ES) is a component essential for proper development of animals, but it can be toxic for aquatic organisms. The objectives of the study reported here included determination of ES concentrations in sediment collected in the area of the Gulf of Gdansk(Baltic Sea) and search for the possible correlations with the ecotoxicity results. Sediment samples were collected from four locations: the Vistula River mouth, in the Port Basin, in the area of discharge of the treated wastewater from the Wastewater Treatment Plant(WWTP) and in the area of the sunken World War Ⅱ s/s 'Stuttgart' shipwreck. The levels of elemental sulfur were determined using a gas chromatograph coupled with a mass spectrometer(GC-MS). Toxicity of marine sediment samples was estimated for three biotest organisms-bioluminescent bacteria Vibrio fischeri, crustacean Heterocypris incongruens, and Synapis alba plant. The highest toxicity of sediments for all indicator organisms was observed in samples taken at the place of the shipwreck(2-100%). The same samples had a high sulfur content(16.7-143.2 μg/g dry weight(d.w.))therefore, it was decided to investigate whether the presence of ES in the sediment in the studied area can have an impact on the results of the ecotoxicity determination in real samples. However, the removal of sulfur from the samples resulted in no significant changes in the level of toxicity of the samples. In this research it could not be confirmed that the presence of elemental sulfur is the only factor responsible for the observed sediment toxicity. It seems that other compounds or their mixtures present in the sediment may have a significant influence on the results obtained.     

Glassy orthopyroxene granodiorites of the Pannonian Basin: tracers of ultra-high-temperature deep-crustal anatexis triggered by Tertiary basaltic volcanism

Glassy orthopyroxene granodiorite-tonalite (named pincinite after type locality) was described from basaltic lapilli tuffs of the Pliocene maar near Pinciná village in the Slovakian part of the Pannonian Basin. Two pincinite types exhibit a qualitatively similar mineral composition (quartz, An_20–55 plagioclase, intergranular silicic glass with orthopyroxene and ilmenite, ±K-feldspar), but strongly different redox potential and formation PT conditions. Peraluminous pincinite is reduced (6–7% of total iron as Fe³⁺ in corundum-normative intergranular dacitic glass) and contains ilmenite with 8–10 mol% Fe₂O₃ and orthopyroxene dominated by ferrosilite. High-density (up to 0.85 g/cm³) primary CO₂ inclusions with minor H₂, CH₄, H₂S, CO and N₂ (<2 mol% total) are present in Qtz and Plg. Equilibrium PT conditions inferred from the intergranular Opx–Ilm–Glass assemblage and fluid density correspond to 1,170±50°C, 5.6±0.4 kbar, respectively. Metaluminous pincinite is more oxidised (25–27% of total iron as Fe³⁺ in diopside-normative intergranular glass of rhyolite–trachyte–dacite composition) and contains Fe₂O₃-rich ilmenite (17–29 mol%) associated with enstatite. Fluid inclusions are composed of CO₂–H₂O mixtures with up to 38 mol% H₂O. Raman spectroscopy revealed H₂S along with dominant CO₂ in the carbonic phase. Equilibrium PT parameters for the intergranular Opx–Ilm–Glass assemblage correspond to 740±15°C, 2.8±0.1 kbar, respectively. Reducing gas species (<2 mol% total) in the CO₂-inclusions of the peraluminous pincinite resulted from hydrogen diffusion due to fH₂ gradient imposed during decrease of redox potential from the log fO₂ values near QFM during Qtz + Plg growth, to QFM-2 incidental to the superimposed Opx + Ilm assemblage in the intergranular melt. The decrease in oxygen fugacity was recorded also in the metaluminous pincinite, where log fO₂ values changed from ~QFM + 2.6 to QFM + 0.4, but hydrogen diffusion did not occur. Absence of OH-bearing minerals, major and trace element abundances (e.g. REE 300–320, Nb 55–57, Th 4–31, Zr 240–300 ppm, FeO_tot/MgO up to 11), and Sr–O isotope ratios in the pincinites are diagnostic of high-temperature anorogenic magmas originated by dehydration melting of biotite in quartz-feldspathoid crust (⁸⁷Sr/⁸⁶Sr>0.705–0.706, ¹⁸O>9 V-SMOW) around alkali basalt reservoir in depths between 17 and 20 km, and around late stage derivatives of the basalt fractionation, intruding the crust up to depths of 10–11 km. Low water activity in the pincinite parental melt was caused by CO₂-flux from the Tertiary basaltic reservoirs and intrusions. The anatexis leads to generation of a melt-depleted granulitic crust beneath the Pannonian Basin, and the pincinites are interpreted as equivalents of igneous charnockites and enderbites quenched at temperatures above solidus and unaffected by sub-solidus re-equilibration and metamorphic overprint.     

Recent insights into the dissolved and particulate fluxes from the Himalayan tributaries to the Ganga River

The Ganga River plays a major role in the transfer of materials from the Indian sub-continent to the Bay of Bengal, both in dissolved and particulate forms. To understand the present elemental dynamics of the Ganga River system, it is important to assess the hydrogeochemical contribution of its tributaries. In this paper, we present an updated database on dissolved and particulate fluxes and denudation rates of the Himalayan tributaries of the Ganga River (Ramganga, Ghaghara, Gandak and Kosi). Dissolved trace element concentrations, their fluxes and suspended sediment-associated elemental fluxes of the Himalayan tributaries have been reported for the first time. Total dissolved flux of the Ramganga, Ghaghara, Gandak and Kosi was estimated as 4, 19.1, 10.3 and 8.8 million tons year^?1 accounting for ~?5.7, ~?27.3, ~?14.7 and ~?12.6%, respectively, of the total annual dissolved load carried by the Ganga River. The total particulate flux of the Ramganga, Ghaghara, Gandak and Kosi was computed as 8.2, 81.6, 30.9 and 19.5 million tons year^?1, respectively. Compared to earlier studies, we have found a significant increase in the total dissolved flux and chemical denudation rate of the studied tributaries. The estimated particulate fluxes were found to be low in comparison to the previous studies. We suggest that a significant increase in the dissolved fluxes and a decrease in the particulate fluxes are an indication of the increasing anthropogenic disturbances in the catchment of these tributaries.     

Passive Seismic Experiment “13 BB Star” in the Margin of the East European Craton,Northern Poland

The lithosphere-asthenosphere boundary (LAB) is investigated recently very effectively, mostly using seismic methods because of their deep penetration and relatively good resolution. The nature of LAB is still debated, particularly under “cold” Precambrian shields and platforms. Passive experiment “13 BB star” is dedicated to study deep structure of the Earth’s interior in the marginal zone of the East European craton in northern Poland. The seismic network consists of 13 broadband stations on the area of ca. 120 km in diameter. The network is located in the area of well-known sedimentary cover and crustal structure. Good records obtained till now, and expected during next 1-year long recording campaign, should yield images of detailed structure of the LAB, ?410”, “?520”, and ?660” km discontinuities, as well as mantle-core boundary and inner core.     

Lagrangian analysis by clustering

We propose a new method for obtaining average velocities and eddy diffusivities from Lagrangian data. Rather than grouping the drifter-derived velocities in geographical bins, we group them by nearest-neighbor distance using a clustering algorithm. This yields sets with approximately the same number of observations, covering unequal areas. A major advantage is that, because the number of observations is the same for the clusters, the statistical accuracy is more uniform than with geographical bins. We illustrate the technique using synthetic data from a stochastic model, employing a realistic mean flow. The latter represents the surface currents in the Nordic Seas and is strongly inhomogeneous in space. We use the clustering algorithm to extract the mean velocities and diffusivities and compare the results with the corresponding quantities from the stochastic model. We perform a similar comparison with the means and diffusivities obtained with geographical bins. Clustering is more successful at capturing the mean flow and improves convergence in the eddy diffusivity estimates. We discuss both the advantages and shortcomings of the new method.     

Aerobic degradation of organic carbon inferred from dinoflagellate cyst decomposition in Southern Ocean sediments

Organic carbon (OC) burial is an important process influencing atmospheric CO₂ concentration and global climate change; therefore it is essential to obtain information on the factors determining its preservation. The Southern Ocean (SO) is believed to play an important role in sequestering CO₂ from the atmosphere via burial of OC. Here we investigate the degradation of organic-walled dinoflagellate cysts (dinocysts) in two short cores from the SO to obtain information on the factors influencing OC preservation. On the basis of the calculated degradation index kt, we conclude that both cores are affected by species-selective aerobic degradation of dinocysts. Further, we calculate a degradation constant k using oxygen exposure time derived from the ages of our cores. The constant k displays a strong relationship with pore-water O₂, suggesting that decomposition of OC is dependent on both the bottom- and pore-water O₂ concentrations.     

Implications of trace element composition of syntaxial quartz cements for the geochemical conditions during quartz precipitation in sandstones

A petrographic investigation revealed polyphase quartz cementation in the Finefrau Sandstone (Upper Carboniferous, Western Germany) and the Solling Sandstone (Lower Triassic, Central Germany). Three different cements could be distinguished in each sandstone based on their cathodoluminescence and trace element composition. The first quartz generation is suggested to have been formed during eogenesis due to dissolution and replacement of feldspar. The mesogenetic paragenesis comprises two generations of quartz and illite, which are accompanied by albite in the Solling Sandstone. Sharp luminescence zoning in quartz overgrowths points to distinct episodes of cementation in both sandstones. Significant amounts of Al, Li and H and traces of Ge and B have been detected in the quartz overgrowths. The Al‐content of the quartz cements in the Finefrau Sandstones exceeds that in the quartz cements in the Solling Sandstone by a factor of five. It is suggested that this compositional variation reflects the conditions in the pore‐water, such as temperature and pH. The Al‐concentration is generally correlated to the Li‐content with the exception of the latest quartz generation in the Finefrau Sandstones which is also most enriched in trace elements. The ratio of Li/Al varies between 0·11 and 0·25 in the two sandstones. The Li/H‐ratio, which ranges from 0·12 to 0·3, is controlled by the activity ratio of Li and H in the pore fluid. Clay minerals are the most important source for Li and high salinities favour the mobilization of Li during diagenesis. Thus, a relatively low salinity and low pH are responsible for the low Li/H‐ratio in the Finefrau Sandstone, while high salinity and neutral to alkaline pH results in a high Li/H‐ratio for the Solling Sandstone. The Ge‐contents are generally near the average of detrital quartz and indicate that pressure dissolution is a major source for quartz cementation. Different chemical compositions of distinct quartz generations indicate changes in the physico‐chemical conditions and point to mobilization of silica from different sources (for example, pressure solution and clay mineral transformations).