  The eruption of multiple flux tubes in a magnetised plasma atmosphere is
proposed as a mechanism for explosive release of energy in plasmas. Linearly
stable isolated flux tubes are shown to be metastable in a box model magnetised
atmosphere in which ends of the field lines are embedded in conducting walls.
The energy released by destabilising such field lines can be a significant
fraction of the gravitational energy stored in the system. This energy can be
released in a fast dynamical time.
