The 2007 Stromboli eruption: Event chronology and effusion rates using thermal infrared data

Using thermal infrared images recorded by a permanent thermal camera network maintained on Stromboli volcano (Italy), together with satellite and helicopter‐based thermal image surveys, we have compiled a chronology of the events and processes occurring before and during Stromboli’s 2007 effusive eruption. These digital data also allow us to calculate the effusion rates and lava volumes erupted during the effusive episode. At the onset of the 2007 eruption, two parallel eruptive fissures developed within the northeast crater, eventually breaching the NE flank of the summit cone and extending along the easternmargin of the Sciara del Fuoco. These fed amain effusive vent at 400m above sea level to feed lava flows that extended to the sea. The effusive eruption was punctuated,on 15 March, by a paroxysm with features similar to those of the 5 April paroxysm that occurred during the 2002–2003 effusive eruption. A total of between 3.2 × 106 and 11 × 106 m3 of lava was erupted during the 2007 eruption, over 34 days of effusive activity. More than half of this volume was emplaced during the first 5.5 days of the eruption. Although the 2007 effusive eruption had an erupted volume comparable to that of the previous (2002–2003) effusive eruption, it had a shorter duration and thus a mean output rate (=total volume divided by eruption duration) that was 1 order of magnitude higher than that of the 2002– 2003 event (∼2.4 versus 0.32 ± 0.28 m3 s−1). In this paper, we discuss similarities and differences between these two effusive events and interpret the processes occurring in 2007 in terms of the recent dynamics witnessed at Stromboli

Coupled Use of COSPEC and Satellite Measurements to define the Volumetric Balance During Effusive Eruptions at Mt. Etna, Italy

Mt. Etna is one of the most studied and extensively monitored volcanoes on earth (Bonaccorso et al., 2004). One of the most frequent hazards are due to the eruption of lava flows, more specifically those flows produced during flank eruptions. These eruptions potentially can produce extensive flows that can inundate densely populated communities of the lower slopes (Guest and Murray, 1979; Behncke et al., 2005). Satellite remote sensing can be used during effusive eruptions to help monitoring the volcano, by determining effusion rates of the flows, aiding in hazard management. The degassing that takes place when magma is rising to the surface can be regularly monitored using ultraviolet spectroscopic methods (e.g. Andres et al., 2001, Sutton et al., 2001). Sulfur Dioxide (SO2) fluxes have been derived from correlation spectrometer (COSPEC) measurements at Mt. Etna (Italy) on a regular basis since 1987 (e.g. Caltabiano et al., 1994; Allard, 1997; Andronico et al., 2005; Burton et al., 2005; Burton et al., in press). Previous studies have compared field-based effusion rates with the measured SO2 fluxes to determine how much of the degassed magma is erupted onto Etna’s flanks in the form of lava flows (Allard, 1997; Harris et al., 2000). However, most of these studies examine bulk volumes erupted over an eruption rather than examining the short-term variations during eruptions. Determining the amount of lava erupted and/or the balance between the amount supplied and the amount erupted remains an unresolved issue. The main objectives of this paper are to examine such short-term variations using satellite-based effusion rates along with regularly measured SO2 fluxes. Using these measurements we determine how and when the volume of supplied magma is balanced by the volume of erupted lava during individual effusive eruptions

The 2007 Stromboli eruption: event chronology and effusion rates using thermal infrared data

Using thermal infrared images recorded by a permanent thermal camera network maintained on Stromboli volcano (Italy), together with satellite and helicopter-based thermal image surveys, we have compiled a chronology of the events and processes occurring before and during Stromboli’s 2007 effusive eruption. These digital data also allow us to calculate the effusion rates and lava volumes erupted during the effusive episode. At the onset of the 2007 eruption, two parallel eruptive fissures developed within the North East crater, eventually breaching the NE flank of the summit cone and extending along the eastern margin of the Sciara del Fuoco. These fed a main effusive vent at 400 m a.s.l. to feed lava flows that extended to the sea. The effusive eruption was punctuated, on 15 March, by a paroxysm with features similar to the 5 April paroxysm that occurred during the 2002-03 effusive eruption. A total of between 3.2 x 106 m3 and 11 x 106 m3 of lava was erupted during the 2007 eruption over 34 days of effusive activity. More than half of this volume was emplaced during the first 5.5 days of the eruption. Although the 2007 effusive eruption had a comparable erupted volume to the previous (2002-03) effusive eruption, it had a shorter duration and thus a mean output rate (= total volume divided by eruption duration) that was one order of magnitude greater than the 2002-03 event (~2.4 m3 s-1 compared with 0.32±0.28 m3 s-1). In this paper, we discuss similarities and differences between these two effusive events, and interpret the processes occurring in 2007 in terms of the recent dynamics witnessed at Stromboli

Scalable Multiprocessor for High-Speed Computing in Space

A report discusses the continuing development of a scalable multiprocessor computing system for hard real-time applications aboard a spacecraft. "Hard realtime applications" signifies applications, like real-time radar signal processing, in which the data to be processed are generated at "hundreds" of pulses per second, each pulse "requiring" millions of arithmetic operations. In these applications, the digital processors must be tightly integrated with analog instrumentation (e.g., radar equipment), and data input/output must be synchronized with analog instrumentation, controlled to within fractions of a microsecond. The scalable multiprocessor is a cluster of identical commercial-off-the-shelf generic DSP (digital-signal-processing) computers plus generic interface circuits, including analog-to-digital converters, all controlled by software. The processors are computers interconnected by high-speed serial links. Performance can be increased by adding hardware modules and correspondingly modifying the software. Work is distributed among the processors in a parallel or pipeline fashion by means of a flexible master/slave control and timing scheme. Each processor operates under its own local clock; synchronization is achieved by broadcasting master time signals to all the processors, which compute offsets between the master clock and their local clocks

Similarities and differences in the historical records of lava dome-building volcanoes: implications for understanding magmatic processes and eruption forecasting

A key question for volcanic hazard assessment is the extent to which information can be exchanged between volcanoes. This question is particularly pertinent to hazard forecasting for dome-building volcanoes, where effusive activity may persist for years to decades, and may be punctuated by periods of repose, and sudden explosive activity. Here we review historical eruptive activity of fifteen lava dome-building volcanoes over the past two centuries, with the goal of creating a hierarchy of exchangeable (i.e., similar) behaviours. Eruptive behaviour is classified using empirical observations that include patterns of SO2 flux, eruption style, and magma composition. We identify two eruptive regimes: (i) an episodic regime where eruptions are much shorter than intervening periods of repose, and degassing is temporally correlated with lava effusion; and (ii) a persistent regime where eruptions are comparable in length to periods of repose and gas emissions do not correlate with eruption rates. A corollary to these two eruptive regimes is that there are also two different types of repose: (i) inter-eruptive repose separates episodic eruptions, and is characterised by negligible gas emissions and (ii) intra-eruptive repose is observed in persistently active volcanoes, and is characterised by continuous gas emissions. We suggest that these different patterns of can be used to infer vertical connectivity within mush-dominated magmatic systems. We also note that our recognition of two different types of repose raises questions about traditional definitions of historical volcanism as a point process. This is important, because the ontology of eruptive activity (that is, the definition of volcanic activity in time) influences both analysis of volcanic data and, by extension, interpretations of magmatic processes. Our analysis suggests that one identifying exchangeable traits or behaviours provides a starting point for developing robust ontologies of volcanic activity. Moreover, by linking eruptive regimes to conceptual models of magmatic processes, we illustrate a path towards developing a conceptual framework not only for comparing data between different volcanoes but also for improving forecasts of eruptive activity

Survival Analysis for Fatigue Reliability Assessments

This research seeks to determine the remaining service life of a bridge or steel member under fatigue loading. The fatigue of engineering materials under repetitive loading affects the durability and design of components and systems in a wide range of engineering-related applications including civil, mechanical, aerospace, automotive and electronics. This is important because fatigue failure is one of the most common types of failures in steel structures. These failures can have catastrophic results and have been estimated to cost the US over $100 billion annually. This research employs a probabilistic approach to fatigue life that utilizes survival analysis, reliability of structures and influencing factors such as stress state, stress range or peak stress, surface conditions, temperature and environmental exposure. Using this probabilistic approach, the research seeks to systematically address all of the factors that contribute to fatigue on a single mathematical platform. This includes using advanced analysis techniques developed for and used in medical research and utilizing these techniques for engineering applications. This research will use these techniques to address the remaining service life and load sequence effects in a probabilistic manner. The research aims to develop, apply and verify survival analysis techniques to the engineering fatigue problem associated with cyclic loading of a wide variety of engineering components

Loss of ASD-associated scaffold Shank3 induces dendritic accumulation of pTau

Synaptic loss is a critical feature in aging and neurodegenerative diseases (ND). In fact, cognitive decline in health and disease is, at least partly, causally linked to altered synaptic structure, plasticity and function. Src homology 3 (SH3) and multiple ankyrin repeat domain (Shank) 3 represents one major scaffold protein at the postsynaptic density and its haploinsufficiency causes the neurodevelopmental disorder Phelan-McDermid-Syndrome, characterized as autism spectrum disorder. Remarkably, a loss of Shank3 has been found in post-mortem tissue of aged individuals as well as in ND models. However, a direct association between the loss of Shank3 and canonical hallmarks of ND such as protein accumulation have not been examined so far. In this study, we aimed at investigating the effects of postsynaptic instability upon Shank3 deficiency on features of neurodegenerative diseases. To this end, we exploited different approaches on murine Shank3-lacking models. After a Western Blot screening for alterations in protein levels characteristic for ND in the cortex and hippocampus of Shank3-knock-out (KO) aged mice, we discovered an increased phosphorylated Tau (pTau) without changes in expression of the total protein, signifying that the Shank3 deficiency has an impact on Tau-modulating pathways. Intriguingly, alterations in Tau are mainly associated with neurodegenerative disorders, so-called “tauopathies”. In further in vitro experiments, we confirmed the enhanced pTau levels upon Shank3 deficiency and explored the dendritic localization of the accumulated protein. Finally, we were able to completely rescue the observed alterations by re-establishing Shank3 expression in conditional Shank3-KO primary neurons, emphasizing the fundamental role of this protein in the insurgence of such phenotype. Still, the exact mechanisms of how the Shank3 deficiency initiates an increased pTau remain unknown. However, altered kinase and phosphatase activities upon the loss of Shank3 can be hypothesized as a causative mechanism leading to upregulated Tau phosphorylation. All in all, we discovered that a postsynaptic instability upon Shank3 deficiency leads to an accumulation of pTau, thus mimicking a neurodegenerative-like phenotype as found in several ND. Hence, the loss of synaptic proteins upon aging might induce neurodegenerative processes, eventually leading to a cognitive decline in the elderly

Temperatures, thermal fluxes and effusion rates associated with the growth of Bezymianny Volcano using spaceborne thermal infrared data

Thesis (M.S.) University of Alaska Fairbanks, 2005Bezymianny Volcano located on the Kamchatka Peninsula, Russia erupts one to two times annually. Often the eruption pattern follows the same cyclic process from slow growth to dome failure and collapse. These dome processes were analyzed during the Fall 2000 eruption using A VHRR, MODIS, ASTER and Landsat ETM + satellite data and field measurements using a Forward Looking Infrared Radiometer (FLIR). These data have a range of resolutions which provide different levels of information which are compared in this thesis. The satellite data showed an increase in thermal flux up to the collapse of the dome and then a sharp decrease there after. Four phases of activity were identified during the Fall 2000 eruption period; precursory, low-level eruption, explosive eruption and the end of the eruption based on temperatures, thermal fluxes, effusion rates, visual and seismic observations. Integrating these different data sets and measurements provided a useful tool to predict future explosive eruption at Bezymianny Volcano. A comparison of thermal data between sensors with variable resolutions allows a better understanding of volcanic processes at lava domes which improves volcano monitoring and eruption predictions.Introduction -- Background -- Bezymianny volcano -- The November 1st 2000 eruption of Bezymianny -- Project data -- Satellite data -- Advanced very high resolution radiometer -- Moderate resolution imaging spectroradiometer -- Advanced spaceborne thermal emissions and reflection radiometer -- Landsat enhanced thematic mapper+ -- Field data -- Methodology -- Digital number to radiance -- Radiance to radiant temperature -- Thermal flux -- Effusion rates -- Field work -- Results -- Temperature results -- Thermal flux results -- Two-component thermal flux results -- Three-component thermal flux results -- Effusion rate results -- Field results -- Discussion -- Eruption phases of Bezymianny -- Thermal flux and effusion rates -- Sensor characteristics -- Field data -- Conclusions -- References cited -- Appendices

A review of algorithms for detecting volcanic hot spots in satellite infrared data

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