Exploring a landslide inventory created by automated web data mining: the case of Italy

Landslides - Nowadays, several systems to set up landslide inventories exist although they rarely rely on automated or real-time updates. Mass media can provide reliable info about natural hazard...     

Potential of radiotelescopes for atmospheric line observations: I. Observation principles and transmission curves for selected sites

Existing and planned radiotelescopes working in the millimetre (mm) and sub-millimetre wavelengths range provide the possibility to be used for atmospheric line observations. To scrutinize this potential, we outline the differences and similarities in technical equipment and observing techniques between ground-based aeronomy mm-wave radiometers and radiotelescopes. Comprehensive tables summarizing the technical characteristics of existing and future (sub)-mm radiotelescopes are given. The advantages and disadvantages using radiotelescopes for atmospheric line observations are discussed. In view of the importance of exploring the sub-mm and far-infrared wavelengths range for astronomical observations and atmospheric sciences, we present model calculations of the atmospheric transmission for selected telescope sites (DOME-C/Antarctica, ALMA/Chajnantor, JCMT and CSO on Mauna Kea/Hawaii, KOSMA/Swiss Alpes) for frequencies between 0 and 2000 GHz () and typical atmospheric conditions using the forward model MOLIERE (version 5). For the DOME-C site, the transmission over a larger range of up to 10 THz () is calculated in order to demonstrate the quality of an Earth-bound site for mid-IR observations. All results are available on a dedicated webpage.     

Land cover change and soil organic carbon stocks in the Republic of Ireland 1851–2000

Using both historic records and CORINE land cover maps, we assessed the impact of land cover change on the stock of soil organic carbon (SOC) in the Republic of Ireland from 1851 to 2000. We identified ten principal land cover classes: arable land, forest, grassland, heterogeneous agricultural areas/other, nonvegetated semi-natural areas, peatland, suburban, urban, water bodies, and wetland. For each land cover class, the SOC stock was estimated as the product of SOC density and land cover area. These were summed to calculate a national SOC budget for the Republic of Ireland. The Republic of Ireland’s 6.94 million hectares of land have undergone considerable change over the past 150 years. The most striking feature is the decrease in arable land from 1.44 million ha in 1851 to 0.55 million ha in 2000. Over the same time period, forested land increased by 0.53 million ha. As of 2000, agricultural lands including arable land (7.85%), grassland (54.33%), and the heterogeneous agricultural areas/other class (7.91%) account for 70.09% of Irish land cover. We estimate that the SOC stock in the Republic of Ireland, to 1 m depth, has increased from 1,391 Tg in 1851 to 1,469 Tg in 2000 despite soil loss due to urbanization. This increase is largely due to the increase of forested land with its higher SOC stocks when compared to agricultural lands. Peatlands contain a disproportionate quantity of the SOC stock. Although peatlands only occupy 17.36% of the land area, as of 2000, they represented 36% of the SOC stock (to 1 m depth).     

Stability at high pressure, elastic behavior and pressure-induced structural evolution of “Al5BO9”, a mullite-type ceramic material

Elastic behavior and pressure-induced structural evolution of synthetic boron-mullite “Al₅BO₉” (a = 5.678(2) Å, b = 15.015(4) Å and c = 7.700(3) Å, space group Cmc2₁, Z = 4) were investigated up to 7.4 GPa by in situ single-crystal X-ray diffraction with a diamond anvil cell under hydrostatic conditions. No phase transition or anomalous compressional behavior occurred within the investigated P range. Fitting the P–V data with a truncated second-order (in energy) Birch-Murnaghan Equation-of-State (BM-EoS), using the data weighted by the uncertainties in P and V, we obtained: V ₀ = 656.4(3) Å³ and K _T0 = 165(7) GPa (β _V0 = 0.0061(3) GPa^?1). The evolution of the Eulerian finite strain versus normalized stress (f _E–F _E plot) leads to an almost horizontal trend, showing that a truncated second-order BM-EoS is appropriate to describe the elastic behavior of “Al₅BO₉” within the investigated P range. The weighted linear regression through the data points gives: F _E(0) = 159(11) GPa. Axial compressibility coefficients yielded: β _a  = 1.4(2) × 10^?3 GPa^?1, β _b  = 3.4(4) × 10^?3 GPa^?1, and β _c  = 1.7(3) × 10^?3 GPa^?1 (β _a :β _b :β _c  = 1:2.43:1.21). The highest compressibilities observed in this study within (100) can be ascribed to the presence of voids represented by five-membered rings of polyhedra: Al1–Al3–Al4–Al1–Al3, which allow accommodating the effect of pressure by polyhedral tilting. Polyhedral tilting around the voids also explains the higher compressibility along [010] than along [001]. The stiffer crystallographic direction observed here might be controlled by the infinite chains of edge-sharing octahedra running along [100], which act as “pillars”, making the structure less compressible along the a-axis than along the b- and c-axis. Along [100], compression can only be accommodated by deformation of the edge-sharing octahedra (and/or by compression of the Al–O bond lengths), as no polyhedral tilting can occur. In addition, a comparative elastic analysis among the mullite-type materials is carried out.     

Alpine tectono‐metamorphic history of the continental units from Vardar zone: the Kopaonik Metamorphic Complex (Dinaric‐Hellenic belt,Serbia)

The easternmost zone of the Dinaric‐Hellenic belt is represented by the Vardar Zone, in which the Kopaonik Metamorphic Complex (KMC) is regarded as the lowermost unit. This complex is topped by the unmetamorphosed Brzece unit and is intruded by the Oligocene Kopaonik Intrusive complex. The KMC is characterized by a stratigraphy that includes metapelites and meta‐carbonates of Late Triassic age, associated with metabasites. It is characterized by a complex deformation history that comprises four phases: D1 to D4. The D1 phase structures occur only as relict structures, whereas the D2 phase structures are represented by isoclinal F2 folds, associated with a well‐developed S2 foliation. The estimated P‐T conditions for the D1 and D2 metamorphism are consistent with the upper greenschist facies. The D3 phase is characterized by west‐verging thrusts associated with upright folds. In contrast, the D4 phase is characterized by open folds (F4) associated with low‐angle normal faults. The D1 and D2 deformation phases developed during the shortening related to continental collision, whereas the subsequent D3 and D4 phases can be related to the progressive exhumation of the KMC. The D4 phase probably developed during extensional tectonics during and after emplacement of the Kopaonik Intrusive Complex. The data show that the continental units belonging to the Vardar zone had a long‐lived deformation history that was more complex that previously thought. Copyright © 2009 John Wiley & Sons, Ltd.     

Monitoring, prediction, and early warning using ground-based radar interferometry

In order to define adequate prevention measures and to manage landslide emergencies, real-time monitoring is required. This paper presents two different applications of the remote sensing technique: the ground-based synthetic aperture radar interferometry, here proposed as a monitoring and early warning support for slope instability. Data acquisitions carried out through a ground-based synthetic aperture radar interferometer, operating in K_u band, installed in front of the observed slopes, are discussed. Two case studies, based on the use of the same apparatus (formerly developed by the Joint Research Center of the European Commission and by Ellegi-LiSALab srl), are reported: the first one concerns the monitoring of a large landslide, named Ruinon (Valfurva, Italy). The second one deals with the monitoring of the NW unstable slope in the Stromboli island aimed to implementing an early warning system. Acquired interferometric data are processed to provide displacements and velocity maps of the monitored area. The monitoring services ongoing on the Ruinon landslide and on Stromboli demonstrate the capability of this technique to operate in different operative settings (i.e., different phenomena and geological framework) and for different aims (monitoring for prevention, early warning, and emergency assessment). This methodology has also been proved by national and regional authorities of civil protection in order to provide a real-time monitoring for emergency management.     

Assessing parameter identifiability for multiple performance criteria to constrain model parameters

ABSTRACT

Reliable simulations of hydrological models require that model parameters are precisely identified. In constraining model parameters to small ranges, high parameter identifiability is achieved. In this study, it is investigated how precisely model parameters can be constrained in relation to a set of contrasting performance criteria. For this, model simulations with identical parameter samplings are carried out with a hydrological model (SWAT) applied to three contrasting catchments in Germany (lowland, mid-range mountains, alpine regions). Ten performance criteria including statistical metrics and signature measures are calculated for each model simulation. Based on the parameter identifiability that is computed separately for each performance criterion, model parameters are constrained to smaller ranges individually for each catchment. An iterative repetition of model simulations with successively constrained parameter ranges leads to more precise parameter identifiability and improves model performance. Based on these results, a more consistent handling of model parameters is achieved for model calibration.     

Origin of metalliferous sediments from the East Pacific Rise

The distribution of several metals in East Pacific Rise sediments, when normalized to Al₂O₃, exhibit stronger maxima near the rise crest than when simply plotted on a carbonate-free basis. The similarity (1) between the distribution of metals in ridge sediments and previously measured mean heat flow values and (2) between the composition of crestal sediments and terrestrial ore bodies associated with greenstone belts, strongly supports a hydrothermal origin for rise crest sediments.     

Definition of pre-2000 m.y. apparent polar movements

In this paper palaeomagnetic poles known to be older than 2000 m.y. in age are assessed in the context of a continental reconstruction derived from younger Precambrian palaeomagnetic results. It is found that the combined data from North America and Africa define a single apparent polar wander path during the intervals 2700-2500 m.y. and 2160-2000 m.y. using the same continental reconstruction as that derived from younger poles. A rapid polar shift is identified at ca. 2150 m.y. and a closed loop is present in the curve between 2160 and 2000 m.y. Palaeomagnetic results from the Rhodesia/Kaapvaal, Kasai, West Africa and North America (Slave and Superior) cratons define segments of this loop which are statistically identical within errors of the pole positions and their assigned ages.These results in common with younger Proterozoic data (2000-800 m.y.) confirm that the crust behaved as an integral unit during these times, although undergoing internal deformation along mobile zones which has not yet proved detectable by the palaeomagnetic method. The 2700-2000 m.y. interval includes the Archaean-Proterozoic transition during which major structural anisotropy began to be imprinted on the sialic crust. Tectonic straight belts and deformed anorthosites lie within a single great-circle belt on the continental reconstruction incorporating Gondwanaland and North America. This same belt later developed into an arc of major tectonic and magmatic activity (<2250 m.y.) including massive anorthosites, rapakivi granites, acidic volcanism and mobile belts.     

Spectroscopic evidence on organically-bound iron in natural and synthetic complexes with humic substances

On the basis of a lack of Mössbauer evidence and of a vague interpretation of some i.r. absorptions, Dicksonet al. (1979) conclude that no iron directly bound to humic materials persists after the usually accepted extraction and separation procedures. Many statements in the paper by Dicksonet al. (1979) appear to be contradictory with this conclusion.In this comment the author has tried to demonstrate that Mössbauer spectroscopy alone cannot give an answer to the problem, but needs further spectroscopic and chemical evidence. Mössbauer data, overinterpreted by Dicksonet al. (1979). have been critically discussed, in comparison with similar data previously obtained by various authors. Large spectroscopic—mainly Mössbauer, ESR and i.r.—evidence have been given in order to demonstrate the already well ascertained existence of organically bound iron in natural and synthetic complexes with humic substances.