Kathryn Street

PhD Project title: The Timing of Volcano-Ice Eruptions and Deglaciation in Iceland.

PhD supervisors: Dr. Ray Burgess & Dr. Simon Brocklehurst, University of Manchester, Dr. Dave McGarvie Open University, Edinburgh.

 

Project Description

      There has been growing interest in the formation of Icelandic subglacial volcanoes (tuyas) due to the information they contain; acting as a physical record of the thicknesses of the ice sheets they erupted beneath. This is because a tuya’s summit elevation is controlled by the minimum thickness of the ice sheet at that location and time.  However, using the tuyas as land based markers of the ice sheets that once covered Iceland is hindered by the lack of reliable eruption ages.

My PhD research is focused on using a relatively new geochronological tool, U-Th/He dating, to obtain ages from olivine in lavas of the basalt tuyas.  The eruption ages gathered using the U-Th/He system, combined with 3He exposure age dating, to enable a reconstruction of the past ice sheet elevation and fluctuations in thickness during glacial-deglacial cycles.  This allows an investigation into what extent exposure ages faithfully reflect episodes of ice sheet thinning and how these relate to climate records in the Northern Hemisphere.  So far, late Quaternary basalts have been sampled from over eighty sites in Iceland; the majority from a transect along the Western and Northern Volcanic Zones.  The olivines are currently being analysed for their He, U and Th content using mass spectrometric techniques.

      Determining reliable ages will also make it possible to assess whether the timing of volcanism is consistent with previous studies specifying that enhanced volcanic activity is realted to the unloading of the ice sheet during deglaciation.  This information carries high value as it enables links between global temperature, ice thickness and palaeoclimate to be explored with greater certainty and clarity.

 

Publication List

Conferences Presented At:

  • Geochemistry Group Research in Progress Meeting 2013, Open University, Milton Keynes (poster)
  • Volcano-Ice Iceland Workshop 2013, Lancaster University (poster)

 

Other Information

Our research group at the University of Manchester (Isotope Cosmochemistry and Geochemistry Group) has a blog on what we all do in our research, including information on Outreach events for the general public.

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