Laser ablation (LA) ICP-MS analyses (presented in parts per million, ppm) of melt inclusions from the 1980 eruption of Mt. St. Helens (18th May-16th October). Detailed sample collection methods are given in Blundy et al. (2008). Blundy, J., Cashman, K.V. and Berlo, K. (2008) Evolving magma storage conditions beneath Mount St. Helens inferred from chemical variations in melt inclusions from the 1980-1986 and current (2004-2006) eruptions, in: Sherrod, D.R., Scott, W.E., Stauffer, P.H. (Eds.), A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006, Reston, VA, pp. 755-790.