Monitoring snow avalanches with seismic stations in north-eastern Italy: a test case

The Regional Agency for the Environmental Prevention and Protection of Veneto (Agenzia Regionale per la Prevenzione e Protezione Ambientale del Veneto, ARPAV) was established in October 2007 to monitor and prevent environmental risks in the Veneto region, in north-eastern Italy. The Italian National Institute for Oceanography and Experimental Geophysics (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, OGS), after the strong earthquake (magnitude M=6.4) occurred in 1976 in the Friuli-Venezia Giulia region, started to operate the North- East Italy (NI) seismic network: it currently consists of 11 very sensitive broad band seismic stations and 21 more simple short period seismic stations, all acquired in real time. OGS also exchanges seismic data with other Italian, Austrian and Slovenian agencies in the surrounding areas, which gives a total number of 73 stations acquired in real time. This makes the OGS the reference agency for the monitoring of the seismic activity in north-eastern Italy. Detecting avalanches by means of seismic stations is indeed a difficult job because of the poor snow-to-earth coupling and the high dumping of the snow. In June 2007 OGS installed in cooperation with the Italian National Institute for Geophysics and Volcanology (Istituto Nazionale di Geofisica e Vulcanologia, INGV) a broad band seismic station in Agordo, a site located on the Dolomites mountains in Veneto. In the first half of December 2008, the Southern Alps have been affected by 2 episodes of intense snowfall: in the whole Dolomites, above the altitude of 1200 m, between 250 and 350 cm of fresh snow have fallen: similar snowfall events occurred in the last 80 years only in December 1979, 1960, 1959 and 1951. The large amount of snow fell in the 2 episodes, on November 28th - December 6th and on December 10th-17th, failed to consolidate and for several days over a large part of the Alps the danger of avalanches was high (grade 4 out of 5 of the European level system). In the Dolomites, the area of interest of this work, the spontaneous avalanche phenomena was very intense, both during the snowfalls and subsequently. During the 2 periods several large avalanches have fallen reaching the bottom of the valley and were detected by the seismic stations: avalanches of such characteristics were not observed since 1987 (January) and 1977 (February). Given the intensity of the snowfalls, it has not been possible to date all the big avalanches, but only those closest to the towns. In this work we analyze the seismic recordings and relate them to the main characteristics of the avalanches

The OGS experience in rapid determination of source parameters and ShakeMaps for NE Italy

OGS manages an integrated seismic network designed to monitor regional seismic activity of North-East Italy (NI) and surroundings. The network includes 11 digital broadband seismometers and 27 short period stations. Waveforms and parametric data are exchanged in real time with the local Civil Defence agencies, the INGV, the Earth Science Department of the University of Trieste, the Zentralanstalt für Meterologie und Geodynamik (ZAMG) in Vienna, and the Agencija Republike Slovenije za Okolje (ARSO) in Ljubljana, in order to support emergency management and seismological studies in the whole Alps–Dinarides junction zone. The Antelope software suite from BRTT has been chosen as the common basis for real time data exchange, rapid location of earthquakes and alerting

FAAS and Antelope: two automatic earthquake location systems in the Northeastern Italy and surrounding areas

non

Ultrasonic monitoring of friction contacts during shear vibration cycles

Complex high-value jointed structures such as aero-engines are carefully designed and optimized to prevent failure and maximise their life. In the design process, physically-based numerical models are employed to predict the nonlinear dynamic response of the structure. However, the reliability of these models is limited due to the lack of accurate validation data from metallic contact interfaces subjected to high-frequency vibration cycles. In this study, ultrasonic shear waves are used to characterise metallic contact interfaces during vibration cycles, hence providing new validation data for an understanding of the state of the friction contact. Supported by numerical simulations of wave propagation within the material, a novel experimental method is developed to simultaneously acquire ultrasonic measurements and friction hysteresis loops within the same test on a high-frequency friction rig. Large variability in the ultrasound reflection/transmission is observed within each hysteresis loop and is associated with stick/slip transitions. The measurement results reveal that the ultrasound technique can be used to detect stick and slip states in contact interfaces subjected to high-frequency shear vibration. This is the first observation of this type and paves the way towards real-time monitoring of vibrating contact interfaces in jointed structures, leading to a new physical understanding of the contact states and new validation data needed for improved nonlinear dynamic analyses

New insights into structural and functional roles of indole-3-acetic acid (IAA) : Changes in DNA topology and gene expression in bacteria

Indole-3-acetic acid (IAA) is a major plant hormone that affects many cellular processes in plants, bacteria, yeast, and human cells through still unknown mechanisms. In this study, we demonstrated that the IAA-treatment of two unrelated bacteria, the Ensifer meliloti 1021 and Escherichia coli, harboring two different host range plasmids, influences the supercoiled state of the two plasmid DNAs in vivo. Results obtained from in vitro assays show that IAA interacts with DNA, leading to DNA conformational changes commonly induced by intercalating agents. We provide evidence that IAA inhibits the activity of the type IA topoisomerase, which regulates the DNA topological state in bacteria, through the relaxation of the negative supercoiled DNA. In addition, we demonstrate that the treatment of E. meliloti cells with IAA induces the expression of some genes, including the ones related to nitrogen fixation. In contrast, these genes were significantly repressed by the treatment with novobiocin, which reduces the DNA supercoiling in bacterial cells. Taking into account the overall results reported, we hypothesize that the IAA action and the DNA structure/function might be correlated and involved in the regulation of gene expression. This work points out that checking whether IAA influences the DNA topology under physiological conditions could be a useful strategy to clarify the mechanism of action of this hormone, not only in plants but also in other unrelated organisms

A flexible and low-cost open-source IPMC mezzanine for ATCA boards based on OpenIPMC

This work presents the development of an Intelligent Platform Management Controller mezzanine in a Mini DIMM form factor for use in electronic boards compliant to the PICMG Advanced Telecommunication Computing Architecture (ATCA) standard. The module is based on an STMicroelectronics STM32H745 microcontroller running the OpenIPMC open-source software. The mezzanine has been successfully tested on a variety of ATCA boards being proposed for the upgrade of the experiments at the HL-LHC, with its design and firmware being distributed under open-source hardware license

Acquiring, archiving, analyzing and exchanging seismic data in real time at the Seismological Research Center of the OGS in Italy

After the 1976 Friuli earthquake (Ms = 6.5) in north-eastern Italy that caused about 1,000 casualties and widespread destruction in the Friuli area, the Italian government established the Centro di Ricerche Sismologiche (CRS). This is now a department of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), and it is specifically devoted to the monitoring of the seismicity of north-eastern Italy. Since its inception, the North-East Italy Seismic Network has grown enormously. Currently, it consists of 14 broad-band and 20 short-period seismic stations, all of which are telemetered to and acquired in real time at the OGS-CRS data center in Udine. Data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of 94 seismic stations acquired in real time, which confirms that the OGS is the reference institute for seismic monitoring of north-eastern Italy. Since 2002, CRS has been using the Antelope software suite as the main tool for collecting, analyzing, archiving and exchanging seismic data. SeisComP is also used as a real-time data exchange server tool. A customized web accessible server is used to manually relocate earthquakes, and automatic procedures have been set-up for moment-tensor determination, shaking-map computation, web publishing of earthquake parametric data, waveform drumplots, state-of-health parameters, and quality checks of the station by spectra analysis. Scripts for email/SMS/fax alerting to public institutions have also been customized. Recently, a real-time seismology website was designed and set-up (http://rts.crs.inogs.it/)