for similar reasons [@Lander2019]. The latter authors have also suggested that the dynamical crust fractures of the crustquake model could be substituted by sustained episodes of accelerated plastic flows which are able to generate large magnetospheric twists on times shorter than the untwisting timescale.

Numerical simulations by @Parfrey2012 [@Parfrey2013] and @Carrasco2019 confirm the instability of the magnetosphere beyond a critical twist, accompanied by the formation of plasmoids. These results are an analogy to the context of eruption processes in the solar corona as found in numerical experiments by @Roumeliotis1994 [@Mikic1994]. The energy dissipated in the reconnection events is sufficient to explain the GF processes [@Parfrey2012]. A caveat to these simulations is that the applied twisting rate is larger than the one expected from the respective magneto-thermal evolution, although it would be fine if the trigger was a rapid plastic deformation.

An alternative approach to the above is the study of stability properties of magnetospheres. A number of authors have constructed equilibrium solutions to the Grad-Shafranov equation (GSE) for neutron star magnetospheres [@Glampedakis2014; @Fujisawa2014; @Pili2015; @Akgun2016; @Kojima2017; @Kojima2018; @Kojima2018b; @Akgun2018a]. @Akgun2017 performed magneto-thermal evolutions coupling the crustal magnetic field at the stellar surface with an exterior equilibrium solution. The results showed 