I have several questions relating to black hole oscillations. Assume throughout what I describe are the reports of an observer outside the event horizon who is not falling into the black hole. (If these questions are trivial, ill-posed or stupid, please tell me and I'll refrain from posting them here in the future.)
1) does the "ringing" of a perturbed black hole actually cause the shape of its event horizon to oscillate- for example, back and forth between an ellipsoid of revolution and an oblate spheroid?
2) in the course of those oscillations, does the area of the EH remain constant over time, or does it oscillate as well?
3) can the dynamics of the black hole's oscillations be perhaps crudely modeled as if the EH were some sort of membrane with a certain amount of surface tension, stiffness, and mass per unit area i.e., as if it behaved somewhat like a soap bubble?
4) do black hole perturbations propagate across the event horizon like waves? if so, what is their propagation velocity as viewed from outside the event horizon?