Volcanica 2018-09-19T17:18:55+00:00 Jamie Farquharson Open Journal Systems <p><em>Volcanica</em>&nbsp;seeks to publish high-quality, rigorously peer reviewed research pertaining to volcanology and related disciplines, while eliminating submission fees and keeping content freely accessible.</p> Field evidence for the lateral emplacement of igneous dykes 2018-08-22T17:36:16+00:00 David Healy Roberto E Rizzo Marcus Duffy Natalie J C Farrell Michael J Hole David Muirhead <p>Seismological and geodetic data from modern volcanic systems strongly suggest that magma is transported significant distance (tens of kilometres) in the subsurface away from central volcanic vents.&nbsp; Geological evidence for lateral emplacement preserved within exposed dykes includes aligned fabrics of vesicles and phenocrysts, striations on wall rocks and the anisotropy of magnetic susceptibility.&nbsp; In this paper, we present geometrical evidence for the lateral emplacement of segmented dykes restricted to a narrow depth range in the crust.&nbsp; Near-total exposure of three dykes on wave cut platforms around Birsay (Orkney, UK) are used to map out floor and roof contacts of neighbouring dyke segments in relay zones.&nbsp; The field evidence suggests emplacement from the WSW towards the ENE, and that the dykes are segmented over their entire vertical extent.&nbsp; Geometrical evidence for the lateral emplacement of segmented dykes is likely more robust than inferences drawn from flow-related fabrics, due to the prevalence of ubiquitous ‘drainback’ events (i.e. magmatic flow reversals) observed in modern systems.</p> 2018-08-22T00:00:00+00:00 ##submission.copyrightStatement## Trashcano: Developing a quantitative teaching tool to understand ballistics accelerated by explosive volcanic eruptions 2018-09-19T17:18:55+00:00 Fabian Ben Wadsworth Holly E Unwin Jérémie Vasseur Ben M Kennedy Julia Holzmueller Bettina Scheu Taylor Witcher Janina Adolf Francisco Cáceres Ana S Casas Valeria Cigala Alexandra Clement Mathieu Colombier Shane Cronin Marcel Cronin Donald B Dingwell Leticia F Guimarães Laura Höltgen Ulrich Kueppers Gilles Seropian Sönke Stern Adrien Teissier Caron Vossen Natalie Weichselgartner <div>Accurate predictions of volcanological phenomena, such as the trajectory of blocks accelerated by volcanic explosions, require quantitative skills training. Large outdoor experiments can be useful to convey concepts of volcanic&nbsp;processes to students in an exciting way. Beyond the fun aspects, these experiments provide an opportunity to&nbsp;engage with the physics of projectile flight and help promote mathematical learning within the Earth Sciences.&nbsp;We present a quantitative framework required to interpret ballistic trajectories and the outdoor experiment known&nbsp;commonly as “trashcano”, taking a step-by-step approach to the physics of this problem, and deriving a range&nbsp;of mathematical solutions involving different levels of complexity. Our solutions are consistent with the predictions from established computer programs for volcanic ballistic trajectory modelling, but we additionally provide&nbsp;a nested set of simplified solutions, useful for a range of teaching scenarios as well as downloadable simulated&nbsp;datasets for use where the full experiment may not be possible.</div> 2018-09-18T14:35:11+00:00 ##submission.copyrightStatement##