Bundle evolution time series. Top: evolution of the longitudinal (green), normal (orange) and binormal velocity component (blue) at the apex of the bundle. Middle: evolution of the Joule volumetric heating rate (dashed red), the viscous volumetric heating rate (dotted red) and the temperature (black) at the apex of the bundle. Bottom: evolution of the average length (blue) and the Alfvén speed at the apex of the loops in the bundle. The blue regions indicate the time range of the two oscillations.