Multiple coincident eruptive seismic tremor sources during the 2014â€“2015 eruption at Holuhraun, Iceland - Eibl, Eva P. S.; Bean, Christopher J.; Jã³nsdã³ttir, Ingibjã¶rg; Hã¶skuldsson, Armann; Thordarson, Thorvaldur; Coppola, Diego; Witt, Tanja; Walter, Thomas R. (Journal of Geophysical Research: Solid Earth, 2017)