List of NordVulk fellows projects offered by IES staff during 2014-2015
1. Age determinations of Plio-Pleistocene and Pleistocene lava formations in and around the western and Northern volcanic zones.
The initial aim of this project is to look into melt segregations in Plio-Pleistocene and Pleistocene basaltic lava flows and find out if they provide suitable material for Potassium-Argon and/or Argon-Argon (or 40Ar/39Ar) dating of volcanic formations in this time period.
Providing positive outcomes, this project then could be developed into a full PhD research project aimed at reconstructing the glacial and interglacial volcanic history for a specific (selected) region and the time period in question.
Main collaborators: Thorvaldur Thordarson, Michael Storey, Olgeir Sigmarsson
Area: Volcanology/geochronology
For more information please contact: torvth@hi.is
2. Eruption dynamics and lava emplacement processes in a basaltic fissure eruption: A case study involving the 1961 event at the Askja volcano North Iceland.
The 1961 Askja eruption is a basaltic fissure eruption where existing data indicates a direct link between changes in magma discharge, style of fountaining at the vents and modes of lava emplacement. The principal aim of this project is to investigate and quantify these changes. This will be achieved by: (i) measuring key physical properties of the tephra fall deposit (e.g. distribution, volume, grain size and pyroclast properties) ; (ii) determining the initial and residual volatile contents via measurements of H2O, CO2, S, Cl, F in melt inclusions and groundmass glass in tephra and lava selvages from the 1961 Askja eruption in order to quantify the role of degassing-induced crystallization in modifying the properties (i.e. viscosity and yield strength) of the magma upon venting; (iii) undertake systematic textural analysis of glassy tephra and lava selvages in order to investigate the thermal history of a’a versus pahoehoe lavas during emplacement and their role in determining flow length.
Main collaborator: Thorvaldur Thordarson
Area: Physical volcanology
For more information please contact: torvth@hi.is
3. Magma degassing in subglacial eruptions: Case study of the Katla 1625, 1721, 1755 events.
Preliminary investigations show that magma degassing in subglacial (phreatomagmatic) eruption is significantly less efficient than in subaerial (magmatic) eruptions or by a factor of 0.5 on average. As this has important implications for understanding the influence of water-to-magma interactions in the shallow conduit as well as determination of atmospheric venting of gasses the principal objective of this project will be to investigate the influence of water –to-magma interaction on magma degassing in selected subglacial eruptions (i.e. Katla 1625, 1721, 1755 events). This will be achieved by systematic sampling of the tephra deposits from previously mentioned eruptions and select a suite of tephra clasts from each event to measure: (i) the initial and residual H2O, CO2, S, Cl, F in the magma via melt inclusions and groundmass glass in tephra; (ii) the vesicle abundance (vesicularity = clast density) and vesicle size distribution in the same clasts. The results will be used investigate the link between volatile concentration and vesicularity in order to produce a model that explains the less efficient degassing in subglacial eruptions.
Main collaborator: Thorvaldur Thordarson
Area: Physical volcanology/petrology
For more information please contact: torvth@hi.is
4. Tephra in lakes and on Land: synchronisation of tephra records in lacustrine sediment and soils in the Hvitarvatn region
Principal objective (aimed at 12 months of work): To measure, sample and analyse tephra from a complete Holocene tephra section in vicinity of Hvitarvatn and link (compare and contrast) the observed tephra stratigraphy with that in the lake. Additional objectives can be developed (depending on the stipend/student), including source identification of the tephra in the section, tephra fall frequency from individual source volcanoes, matters related to preservation (comparison with the lake record) etc.
Main collaborators: Thorvaldur Thordarson, Áslaug Geirsdottir, Gifford H Miller.
Area: Volcanology/quaternary geology
For more information please contact: torvth@hi.is
5. Tectonic mapping in the Vestfjords by remote sensing techniques
The LANDSAT 8 satellite from NASA was launched in early 2013. It has 11 spectral bands, thereof two thermal and one panchromatic (15 m geometric resolution). USGS and NASA make the images available online in full resolution in near real time. During the Autumn 2013, a number of images were obtained showing Iceland covered with thin snow cover and under a low solar angle; ideal conditions to study landscape and tectonics.
We propose to have a postdoc or PhD project on LANDSAT 8 images of Vestfirðir, an area that has not been analysed this way before, to examine the tectonic patterns in connection with geophysical processes. The project would include testing of image processing methods to enhance the structure and appearance of fissures, and Geographical Information Systems for mapping and statistical analysis. Other geophysical and remote sensing data would be used for further interpretation.
Main collaborators: Páll Einarsson and Ingibjörg Jónsdóttir
Area: Tectonics/Remote sensing
For more information please contact: palli@hi.is or ij@hi.is
6. Climatic fingerprints of volcanic eruptions
Principal objective: To study volcanic tracers in Greenland ice cores and link to the isotopic profiles of the cores to identify possible fingerprints of volcanic eruptions on climate parameters.
The project involves isotopic measurements of ice cores on the IES Picarro analyzer, study of available chemical tracers within the cores, source-identification of tephra, and isotope enabled GCM model calculations (REMOiso, ECHHAM5-wiso).
It might be possible to divide the project up into two, namely 1) identifying Icelandic volcanoes in Greenland Ice Cores and 2) study the climatic (isotope) fingerprint as recorded by ice cores in Greenland from volcanic eruptions (effect from local / Icelandic volcanoes and from volcanoes far away).
Main collaborators: Árný E. Sveinbjörnsdóttir (arny@hi.is), Hans Christian Steen Larsen (hanschr@nbi.ku.dk), Jesper Sjolte (jesper.sjolte@geol.lu.se), Bo Vinther (bo@gfy.ku.dk)
Area: Climate change
For more information please contact: arny@hi.is or any of the collaborators
7. Intrusive growth and magma transport in central volcanoes - How do cone-sheets form?
Swarms of thousands of cone sheets, cone-shaped dykes, make up the interior of many of the eroded central volcanoes in Iceland, which stresses the significance of cone sheets in magma transport from the shallow magma reservoir. Furthermore, the abundance of cone sheets indicates that cone-sheet emplacement is an important mechanism of edifice growth. However, the dynamic emplacement of cone-sheets is still controversial.
The main aim of this 1-2 year project is to analyse cone-sheet emplacement by combining systematic structural mapping, statistical analysis, state-of-the-art 3D modelling with (for an optional 2nd year) measurements of the magnetic fabric (through AMS) in cone sheets of the Thingmuli central volcano in Eastern Iceland. The shallow magmatic plumbing system of Thingmuli is well exposed and suitable for structural field work and sampling.
Main collaborators: Morten S. Riishuus, Steffi Burchardt
Area: Structural volcanology
For more information please contact: riishuus@hi.is or steffi.burchardt@geo.uu.se