THE ACCELEROMETRIC NETWORK OF THE INDES-MUSA PROJECT IN THE KALOCHORI AREA: CONFIGURATION, DOCUMENTATION AND PRELIMINARY DATA INTERPRETATION

Ένα δίκτυο επτά επιταχυνσιογράφων στην επιφάνεια του εδάφους και σε κατασκευές εγκαταστάθηκε πρόσφατα στην ευρύτερη περιοχή Καλοχωρίου, δυτικά της Θεσσαλονίκης, στο πλαίσιο του ερευνητικού έργου INDES-MUSA ως τμήμα πολυπαραμετρικού δικτύου καταγραφής της σεισμικής κίνησης και της εδαφικής υποχώρησης της περιοχής. Το δίκτυο περιλαμβάνει σταθμούς εγκατεστημένους στην επιφάνεια του εδάφους και στην κορυφή τυπικών κατασκευών εντός αστικών υποσυνόλων καθώς και ένα σταθμό ελευθέρου πεδίου. Όλοι οι σταθμοί έχουν τεκμηριωθεί καταλλήλως, λαμβάνοντας υπόψη τα ιδιαίτερα χαρακτηριστικά της κάθε εγκατάστασης καθώς και τα χαρακτηριστικά της εδαφικής δομής, όπως αυτά εκφράζονται από την κατανομή με το βάθος της ταχύτητας διάδοσης των διατμητικών κυμάτων σε κάθε θέση. Παρουσιάζονται καταγραφές του δικτύου επιταχυνσιογράφων από τριαντά εννιά σεισμούς και δίνεται η διαδικασία διόρθωσης που εφαρμόστηκε στις πρωτογενείς χρονοϊστορίες επιτάχυνσης κατά το στάδιο επεξεργασίας και αποθήκευσης των σημάτων. Τέλος, παρουσιάζονται προκαταρκτικές συγκρίσεις τιμών μέγιστης εδαφικής επιτάχυνσης μεταξύ σταθμών εντός οικιστικής ζώνης και ελευθέρου πεδίου καθώς και συγκρίσεις φασματικών λόγων οροφής κατασκευών και βάσης με σκοπό την προκαταρκτική εκτίμηση των θεμελιωδών δυναμικών χαρακτηριστικών των ενοργανωμένων κατασκευών. Τα παραπάνω δεδομένα καταγραφών και τεκμηρίωσης είναι διαθέσιμα μέσω της διαδικτυακής πλατφόρμας Web-GIS του έργου INDESMUSA. A network of seven accelerometric stations on both ground surface and structures has been recently installed, as part of a multi-sensor network for monitoring seismic motion and ground subsidence in the broader area of Kalochori, west of Thessaloniki in Northern Greece, within the INDES-MUSA project. This network includes ground installations within the urban area, structural stations on top of structures and a freefield station away from the building stock. The documentation of stations is presented including shear wave velocity profiles of the subsoil at each location. A set of thirtynine earthquakes recorded so far by the accelerometric network is reported, followed by data processing procedures performed in the acquired waveforms. Comparisons of the processed earthquake recordings are presented referring to (a) the urbanground and the free-field stations in terms of peak ground acceleration, indicating amplification trends of ground motion, and (b) the structural and the nearby urban ground stations by means of top-to-base ratios in the frequency domain, towards a preliminary identification of the fundamental vibrational characteristics of the instrumented structures. The processed acceleration data are available through the INDES-MUSA Web-GIS portal

Seismic wave amplification: Basin geometry vs soil layering.

International audienceThe main purpose of the paper is to analyze seismic site effects in alluvial basins and to discuss the influence of the knowledge of the local geology on site amplification simulations. Wave amplification is due to a combined effect of impedance ratio between soil layers and surface wave propagation due to the limited extent of the basin. In this paper, we investigate the influence of the complexity of the soil layering (simplified or detailed layering) on site effects in both time and frequency domain. The analysis is performed by the Boundary Element Method. The European test site of Volvi (Greece) is considered and 2D amplification in the basin is investigated for various soil models. Seismic signals are computed in time domain for synthetic Ricker signals as well as actual measurements. They are analyzed in terms of amplification level as well as time duration lengthening (basin effects) for both SH and SV waves. These results show that the geometry of the basin has a very strong influence on seismic wave amplification in terms of both amplification level and time duration lengthening. The combined influence of geometry/layering of alluvial basins seems to be very important for the analysis of 2D (3D) site effects but a simplified analysis could sometimes be sufficient. In the case of Volvi European test site, this influence leads to (measured and computed) 2D amplification ratios far above 1D estimations from horizontal layering descriptions

Metrics for Aggregating the Climate Effect of Different Emissions: A Unifying Framework. ESRI WP257, September 2008

Multi-gas approaches to climate change policies require a metric establishing “equivalences” among emissions of various species. Climate scientists and economists have proposed four classes of such metrics and debated their relative merits. We present a unifying framework that clarifies the relationships among them. We show that the Global Warming Potential, used in international law to compare greenhouse gases, is a special case of the Global Damage Potential, assuming (1) a finite time horizon, (2) a zero discount rate, (3) constant atmospheric concentrations, and (4) impacts that are proportional to radiactive forcing. We show that the Global Temperature change Potential is a special case of the Global Cost Potential, assuming (1) no induced technological change, and (2) a short-lived capital stock. We also show that the Global Cost Potential is a special case of the Global Damage Potential, assuming (1) zero damages below a threshold and (2) infinite damage after a threshold. The UN Framework Convention on Climate Change uses the Global Warming Potential, a simplified cost-benefit concept, even though the UNFCCC frames climate policy as a cost-effectiveness problem and should therefore use the Global Cost Potential or its simplification, the Global Temperature Potential

Metrics for aggregating the climate effect of different emissions: A unifying framework

Multi-gas approaches to climate change policies require a metric establishing equivalences among emissions of various species. Climate scientists and economists have proposed four classes of such metrics and debated their relative merits. We present a unifying framework that clarifies the relationships among them. We show that the Global Warming Potential, used in international law to compare greenhouse gases, is a special case of the Global Damage Potential, assuming (1) a finite time horizon, (2) a zero discount rate, (3) constant atmospheric concentrations, and (4) impacts that are proportional to radiative forcing. We show that the Global Temperature change Potential is a special case of the Global Cost Potential, assuming (1) no induced technological change, and (2) a short-lived capital stock. We also show that the Global Cost Potential is a special case of the Global Damage Potential, assuming (1) zero damages below a threshold and (2) infinite damage after a threshold. The UN Framework Convention on Climate Change uses the Global Warming Potential, a simplified cost-benefit concept, even though the UNFCCC frames climate policy as a cost-effectiveness problem and should therefore use the Global Cost Potential or its simplification, the Global Temperature Potential

NERA project - Deliverable D11.4: Array measurements

The aim of this Task is to present the seismological data and some preliminary empirical results related to two deployed specific arrays; (a) the Argostoli seismological array and (b) the Fucino seismological array. Both experiment arrays provided high quality data that along with corresponding geological and geophysical measurements may serve to critical evaluation of site effects and basin effects. In addition, work on modelling of basin effects may be significantly benefited by the observed acquired in both sites. Given that the analyses of the data obtained during the aforementioned experimental arrays will be performed in close link with activity of NERA-JRA3, the following goals are set: To investigate the link between ground motion spatial variability, strains, seismic wavefield and subsurface properties To compare numerical estimates of ground strain with actual measurements To investigate the capability of estimating ground strains from noise correlation studies. In order to organize and accomplish the work according to the initial schedule, several meetings (actual or/and Skype) among the participants took place during the 2nd year of the NERA-JRA1 project. Minutes of these meetings are given in Appendices 1, 2, 3 and 4.Network of European Research Infrastructures for Earthquake Risk Assessment and Mitigation Project, Seventh Framework Programme EC project number: 262330Published4T. Sismologia, geofisica e geologia per l'ingegneria sismic

Temperature-related changes in airborne allergenic pollen abundance and seasonality across the northern hemisphere : a retrospective data analysis

BACKGROUND: Ongoing climate change might, through rising temperatures, alter allergenic pollen biology across the northern hemisphere. We aimed to analyse trends in pollen seasonality and pollen load and to establish whether there are specific climate-related links to any observed changes. METHODS: For this retrospective data analysis, we did an extensive search for global datasets with 20 years or more of airborne pollen data that consistently recorded pollen season indices (eg, duration and intensity). 17 locations across three continents with long-term (approximately 26 years on average) quantitative records of seasonal concentrations of multiple pollen (aeroallergen) taxa met the selection criteria. These datasets were analysed in the context of recent annual changes in maximum temperature (T) and minimum temperature (T) associated with anthropogenic climate change. Seasonal regressions (slopes) of variation in pollen load and pollen season duration over time were compared to T, cumulative degree day T, T, cumulative degree day T, and frost-free days among all 17 locations to ascertain significant correlations. FINDINGS: 12 (71%) of the 17 locations showed significant increases in seasonal cumulative pollen or annual pollen load. Similarly, 11 (65%) of the 17 locations showed a significant increase in pollen season duration over time, increasing, on average, 0·9 days per year. Across the northern hemisphere locations analysed, annual cumulative increases in T over time were significantly associated with percentage increases in seasonal pollen load (r=0·52, p=0·034) as were annual cumulative increases in T (r=0·61, p=0·010). Similar results were observed for pollen season duration, but only for cumulative degree days (higher than the freezing point [0°C or 32°F]) for T (r=0·53, p=0·030) and T (r=0·48, p=0·05). Additionally, temporal increases in frost-free days per year were significantly correlated with increases in both pollen load (r=0·62, p=0·008) and pollen season duration (r=0·68, p=0·003) when averaged for all 17 locations. INTERPRETATION: Our findings reveal that the ongoing increase in temperature extremes (T and T) might already be contributing to extended seasonal duration and increased pollen load for multiple aeroallergenic pollen taxa in diverse locations across the northern hemisphere. This study, done across multiple continents, highlights an important link between ongoing global warming and public health-one that could be exacerbated as temperatures continue to increase. FUNDING: None

Ragweed as an Example of Worldwide Allergen Expansion

<p/> <p>Multiple factors are contributing to the expansion of ragweed on a worldwide scale. This review seeks to examine factors that may contribute to allergen expansion with reference to ragweed as a well-studied example. It is our hope that increased surveillance for new pollens in areas not previously affected and awareness of the influence the changing environment plays in allergic disease will lead to better outcomes in susceptible patients.</p