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dc.contributor.advisorWhite, James
dc.contributor.advisorValentine, Greg
dc.contributor.authorAndrews, Robin George
dc.date.available2015-06-15T21:16:15Z
dc.date.copyright2015
dc.identifier.citationAndrews, R. G. (2015). Approaches in Experimental Volcanology: Bench-Scale, Field-Scale and Mathematical Modelling of Maar-Diatreme Systems (Thesis, Doctor of Philosophy). University of Otago. Retrieved from http://hdl.handle.net/10523/5716en
dc.identifier.urihttp://hdl.handle.net/10523/5716
dc.description.abstractIn recent decades, major fieldwork studies have greatly advanced our knowledge of maar-diatreme systems, the second most common type of volcano; despite this, much of the interpretation is strongly debated. My original contribution to volcanological research is twofold: firstly, successfully simulating maar-diatreme systems using analogue experimentation in order to determine the processes that generate them; secondly, using mathematical modelling to produce a predictive model for their total energy release during an eruption. This study uses a tripartite, quantitative approach: (1) bench-scale experiments are used to generate simulated maar-diatreme volcanoes and examine their eruption and depositional processes; (2) these are qualitatively compared and quantitatively scaled to both field-scale experiments and natural maar-diatreme volcanoes; and (3) the 1886 maar-forming Rotomahana eruption is used as a case study for a new thermodynamic model which gives a first-order calculation of the cumulative energy change during the event. This study finds that maar-diatreme volcanoes can form through both ascending and descending blast series; multiple types of diatreme can form depending on the blast pattern. Debris jets responsible for the genesis of such systems are two-tier processes: the crater excavation and upward entrainment processes are temporally segregated. The behaviour of the explosively generated cavities, the preservation potential of the system architecture, and the stratigraphic partitioning of blast energy are controlled by mathematical relationships between blast depth and energy. Comparing the simulated volcanoes’ sedimentological architecture to natural examples reveals additional information regarding their eruption history and depositional processes. Data produced by the thermodynamic modelling of the 1886 Rotomahana event corroborates with both fieldwork studies and direct observations, and reveals the eruption was overwhelmingly dominated by a thermal component; this predictive model is hypothetically applicable to similar volcanic systems. A new conceptual model of maar-diatreme formation is conceived based on a synthesis of the findings of this thesis.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherUniversity of Otago
dc.rightsAll items in OUR Archive are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectExperimental Volcanology
dc.subjectmaar-diatreme volcanoes
dc.subjectbench-scale experiments
dc.subjectfield-scale experiments
dc.subjectmathematical modelling
dc.subjectphreatomagmatism
dc.titleApproaches in Experimental Volcanology: Bench-Scale, Field-Scale and Mathematical Modelling of Maar-Diatreme Systems
dc.typeThesis
dc.date.updated2015-06-15T14:39:51Z
dc.language.rfc3066en
thesis.degree.disciplineGeology
thesis.degree.nameDoctor of Philosophy
thesis.degree.grantorUniversity of Otago
thesis.degree.levelDoctoral
otago.openaccessOpen
otago.evidence.presentYes
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