This Hekla 2000 project has been a really fun learning experience for me, going from using tephras primarily to correlate and date other deposits to specifically looking at the tephra itself. It is amazing what you can find out about a past eruption from some bags of tephra.
Samples of Hekla 2000 tephra were collected shortly after the eruption by Guðrún Larsen at the University of Iceland and other scientisits and members of the public in Iceland. It is quite unusual to have such fresh material to look at and this means that we can look at the tephra itself, hopefully reducing complications of years of reworking, compaction and contamination.
During this project I have worked with Costanza Bonadonna at the University of Geneva who has given me a lot of training and encouragment, as well as Sebastian Biass at the University of Geneva, Guðrún Larsen, Ármann Höskuldsson and Freysteinn Sigmundsson at the University of Iceland. Initial funding came from Landsvirkjun (Icelandic energy company) and the University of Iceland postdoctoral fund.
We have:
- carried out grain size analyses on 31 new samples of Hekla 2000 tephra and estimated the total grain size distribution,
- carried out grain size analyses on 2 samples collected near Hekla in October 2008,
- analysed the componentry of the deposit and the density of tephra clasts,
- re-considered the isomass mapping of the deposit and estimated volume and mass,
- investigated mass eruption rate,
- produced hazard curves for selected sites in southern Iceland for a VEI3 eruption of Hekla (Seb Biass)
