We have investigated the physical properties of ash samples from the recent Icelandic volcanic eruptions, motivated by two sets of unexplained electrical measurements. Firstly, in situ observations of sustained electrical charging of the Eyafjallajökull plume at 1200 km from the volcano (Harrison et al, 2010), and secondly, the rate of volcanic lightning from Grimsvötn was two orders of magnitude greater than at Eyafjallajökull (Bennett et al, 2010). Electrification of volcanic plumes is likely to be generated by multiple mechanisms which may include: triboelectric or fractoemission processes at the vent, the ‘dirty thunderstorm’ mechanism if ice forms in the plume, and the internal radioactivity of the plume (Mather and Harrison, 2006; James et al., 2008). Here we investigate the charging properties of the ash from the two eruptions, determined by a combination of the material (including natural radioactivity), particle size distribution and shape.
|Translated title of the contribution||Electrical and radioactive properties of ash samples from Eyafjallajökull and Grimsvötn|
|Title of host publication||EGU 2012|
|Number of pages||1|
|Publication status||Published - Apr 2012|
Bibliographical noteConference Proceedings/Title of Journal: Geophysical Research Abstracts
Conference Organiser: European Geophysics Union