Volcanica https://www.jvolcanica.org/ojs/index.php/volcanica <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> en-US <p>Submission of an original manuscript to <em>Volcanica&nbsp;</em>will be taken to mean that it represents original work <strong>not previously published</strong>, and <strong>not being considered for publication elsewhere</strong>.&nbsp;</p> jifarq89@googlemail.com (Jamie Farquharson) farquharson@jvolcanica.org (Jamie Farquharson) Wed, 22 Aug 2018 17:25:36 +0000 OJS 3.1.0.0 http://blogs.law.harvard.edu/tech/rss 60 Field evidence for the lateral emplacement of igneous dykes https://www.jvolcanica.org/ojs/index.php/volcanica/article/view/13 <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> David Healy, Roberto E Rizzo, Marcus Duffy, Natalie J C Farrell, Michael J Hole, David Muirhead ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 https://www.jvolcanica.org/ojs/index.php/volcanica/article/view/13 Wed, 22 Aug 2018 00:00:00 +0000 Trashcano: Developing a quantitative teaching tool to understand ballistics accelerated by explosive volcanic eruptions https://www.jvolcanica.org/ojs/index.php/volcanica/article/view/4 <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> 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 ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 https://www.jvolcanica.org/ojs/index.php/volcanica/article/view/4 Tue, 18 Sep 2018 14:35:11 +0000