During a compact loop flare an individual coronal loop brightens but the loop structure is not destroyed and the energy released is much less than that released during a two ribbon flare.
Coronal loops have footpoints embedded in the much denser photosphere.
However photospheric motions at the loop footpoints can twist the loop. Once the twist has exceeded some critical value the loop will become unstable to the kink instability. It has been suggested that during the non-linear evolution of this instability current sheets may form and if the plasma is resistive reconnection will occur releasing the free magnetic energy in the form of heat and motion. These two movies are taken from simulations of this process carried out using a new Lagrangian remap code, lare3d. They show isosurfaces of the current.