Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 74 for “"Volcanic Eruptions"”.
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Fracture mechanics of volcanic eruptions
Seismology is a key tool in the forecasting of volcanic eruptions. The onset of an eruption is often preceded and accompanied by an increase in local seismic activity, driven by fracturing within the edifice. For closed systems, with a repose interval of the order of a century or more, this …
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Perchlorate Variations Over 300 Years: Influence of Human Activities, Volcanic Eruptions and Bolide Events
… Furthermore, a link between large, stratospheric volcanic eruptions and brief periods of increased perchlorate concentrations has been discovered. These volcanic eruptions increase stratospheric H2SO4 aerosols, which provides a surface for heterogeneous chlorine activation, resulting in increased …
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CO2 Adsorption On Volcanic Ash: Net Contribution Of Volcanic Eruptions To The Global Carbon Cycle
… a small percentage of the terrestrial co2 sink. Volcanic ash is virtually free of co2 when erupted and has a high surface area resulting in a high capacity for co2 adsorption. Volcanism is commonly assumed to be only a source of co2, but pyroclastic eruptions can also potentially serve as a sink. …
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Utilizing Changes in Repeating Earthquakes to Monitor Evolving Processes and Structure Before and During Volcanic Eruptions
… changes have been observed prior to several volcanic eruptions, are thought to occur in response to volumetric strain and the opening or closing of cracks in the subsurface. We compared continuous records of velocity change against other geophysical data, and found that velocities at Mount …
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Observation of sulphate aerosols and SO2 from volcanic eruptions using data from the Atmospheric Chemistry Experiment (ACE)
… to analyse the temporal and spatial evolution of volcanic aerosols from the Kasatochi (August 2008), Sarychev (June 2009) and Grimsvötn (May 2011) eruptions. Evidence of the Kasatochi and Sarychev eruptions has first be seen one month after the eruptions, while the Grimsvötn plume has been …
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The impact of volcanic halogens, climate change, and sulfate aerosol geo-engineering on the atmospheric effects of volcanic eruptions
The evolution of volcanic sulfur, stratospheric composition and radiative forcing following explosive volcanic eruptions injecting sulfur directly into the stratosphere is well understood. However, how the co-emission of volcanic halogens, climate change, and concurrent sulfate aerosol …
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Quantifying future volcanic impacts on climate projections and their uncertainties using stochastic volcanic emissions
Explosive volcanic eruptions can inject sulfur dioxide into the stratosphere, forming sulfate aerosols that alter Earth’s radiative balance leading to abrupt climatic changes. Despite the importance of volcanic stratospheric aerosols for climate, current climate projection studies rely on two …
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An overview of the volcano-tectonic hazards of Portland, Oregon, and an assessment of emergency preparedness
… the city at risk to hazards from earthquakes and volcanic eruptions. The young Juan de Fuca microplate is subducting under North America, introducing not only arc magmatism into the overlying plate, but also interplate and intraplate seismicity related to the subduction zone. Large crustal …
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The role of ecological barriers in the development of cultural boundaries during the later Holocene of the central Alaska peninsula
"This study assesses the capability of very large volcanic eruptions to effect widespread ecological and cultural change. It focuses on the proximal and distal effects of the Aniakchak volcanic eruption that took place approximately 3400 rcy BP on the central Alaskan Peninsula. The research is …
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Volcano deformation analysis in the Lazufre area (central Andes) using geodetic and geological observations
Large-scale volcanic deformation recently detected by radar interferometry (InSAR) provides new information and thus new scientific challenges for understanding volcano-tectonic activity and magmatic systems. The destabilization of such a system at depth noticeably affects the surrounding …
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The effects of volcanic aerosols on mid-latitude ozone recovery
… Community Model (SD-WACCM), the impacts of volcanic aerosols on mid-latitude ozone loss are investigated. These results are compared to the ozone column expected recovery from a run of SD-WACCM with no volcanic eruptions in the same period. Particular emphasis is placed on the last decade to …
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Ozone Chemistry in the Lower Stratosphere: Drivers, Trends, and Impacts
… First, the impact of large and moderate sized volcanic eruptions on anthropogenically driven ozone depletion and recovery trends is explored. Results confirm previous work showing that large volcanic eruptions increased the rate of ozone depletion prior to the mid-1990s, and for the first time …
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The influence of volcanic stratospheric aerosols on interannual global climate variations
… Nino/Southern Oscillation (ENSO) by low-latitude volcanic stratospheric aerosols (Handler 1989). This mechanism is based on the normal global annual cycle resulting from the normal annual cycle in the distribution of incoming solar radiation. The presence of a volcanic stratospheric aerosol, which …
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The role of Deception Island in the development of Antarctic affairs
… the final evacuation of the island due to the volcanic eruptions in 1961, 1969 and 1970, It suggests that there can be a future for Deception Island so that once again it can assume an important place in the events of this region and become again the 'capital'.
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Exploration of natural climate variability and changes in future events using observations, proxy data and model simulations
… such as those caused by human activities, volcanic eruptions, and the planet’s orbital configuration; and internally generated changes arising from the natural interactions among these Earth systems. Herein I attempt to make a contribution to the current understanding of the history of the …
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Forcings on Coccolithophore Evolution and Assemblage Changes
… baseline information to assess the impacts of a volcanic supereruption and a warm interstadial–cold stadial climate transition on the marine ecosystem. Primary productivity (based on a coccolithophore proxy) significantly increased in the northeastern Arabian Sea for about 8–19 years after the …
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