1. a Mercator and Ortelius Research Centre for Eruption Dynamics , Department of Geology and Soil Science , Ghent University , Krijgslaan 281/S8, B‐9000 Ghent, Belgium
2. b HIGP/SOEST , University of Hawaii at Mānoa , 1680 East‐West Road, Honolulu, Hawaii 96822, USA
3. c Developmental Studies Department , Middle Tennessee State University , Murfreesboro, TN 37132, USA
4. d Department of Geology , University of Dar es Salaam , Tanzania