Opin vísindi

Linking lava flow morphology, water availability and rootless cone formation on the Younger Laxá Lava, NE Iceland

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dc.contributor Háskóli Íslands
dc.contributor University of Iceland
dc.contributor.author Boreham, Frances
dc.contributor.author Cashman, Katharine
dc.contributor.author Rust, Alison
dc.contributor.author Höskuldsson, Ármann
dc.date.accessioned 2019-10-02T14:39:33Z
dc.date.available 2019-10-02T14:39:33Z
dc.date.issued 2018-09
dc.identifier.citation Boreham, F., Cashman, K., Rust, A., & Höskuldsson, Á. (2018). Linking lava flow morphology, water availability and rootless cone formation on the Younger Laxá Lava, NE Iceland. Journal of Volcanology and Geothermal Research, 364, 1-19. doi:https://doi.org/10.1016/j.jvolgeores.2018.08.019
dc.identifier.issn 0377-0273
dc.identifier.uri https://hdl.handle.net/20.500.11815/1285
dc.description Publisher's version (útgefin grein)
dc.description.abstract It is well established that rootless cones and associated deposits are the result of explosive interactions between lava flows and environmental water, but there is substantial uncertainty about the dynamics of rootless eruptions, particularly the relative importance of lava supply, water availability and the conditions under which they meet. Here we present a case study of the Younger Laxá Lava in NE Iceland, and the >6500 rootless cones that it created. Critically, this long (63 km) lava flow interacted with water along its length, from flow through/around a large lake (Mývatn), down a narrow river gorge (Laxárdalur) and across a broad glacial valley with wetlands and rivers (Aðaldalur). Using high-resolution digital terrain models and aerial photographs, we map the flow surface morphology, and classify, measure and analyse the rootless cone type, size and spatial distribution in the context of both lava and water availability. We find that rootless cone size is controlled by the combined availability of lava and water: large rootless cones require sustained, high volumes of lava (related to proximity to vent) and water (e.g., Lake Mývatn), whereas limited supplies of lava (with distance from the vent and from the centre of the flow) and water (particularly in dammed river valleys) build smaller cones. Where we infer that where water was distributed in sediment, the lava–water interaction style changed to low-energy and distributed bubble bursts that created >3000 hornitos in the lower reaches of Aðaldalur. The distribution of rootless cones around Mývatn also defines the pre-eruption extent of the lake and suggests substantial lake level changes during the course of the eruption. By looking at the variation in rootless cone type and size in the context of the parent lava flow and the local environment, we explain how the availability of water and local mass flow rate of lava affect the dynamics of rootless eruptions.
dc.description.sponsorship This work was supported by the Natural Environmental Research Council [grant no: NE/L002434/1], and on AXA Research Fund and Wolfson Merit Award to KVC. DTMs provided by the Polar Geospatial Center under NSF OPP awards 1043681, 1559691 and 1542736.
dc.format.extent 1-19
dc.language.iso en
dc.publisher Elsevier BV
dc.relation.ispartofseries Journal of Volcanology and Geothermal Research;364
dc.rights info:eu-repo/semantics/openAccess
dc.subject Rootless cone
dc.subject Pseudocrater
dc.subject Hydrovolcanism
dc.subject Lava–water interaction
dc.subject Hornito
dc.subject Eldkeilur
dc.subject Hraunrennsli
dc.subject Vatn
dc.subject Gervigígar
dc.title Linking lava flow morphology, water availability and rootless cone formation on the Younger Laxá Lava, NE Iceland
dc.type info:eu-repo/semantics/article
dcterms.license This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
dc.description.version Peer Reviewed
dc.identifier.journal Journal of Volcanology and Geothermal Research
dc.identifier.doi 10.1016/j.jvolgeores.2018.08.019
dc.contributor.department Jarðvísindastofnun (HÍ)
dc.contributor.department Institute of Earth Sciences (UI)
dc.contributor.school Verkfræði- og náttúruvísindasvið (HÍ)
dc.contributor.school School of Engineering and Natural Sciences (UI)

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