A.F. Cook II C. Sagan L.A. Soderblom T. V. Johnson 1979 Resurfacing rates and surface ages on Io are estimated, together with the material ejection and deposition rates of the active volcanic plumes. ?? 1979 Nature Publishing Group. application/pdf 10.1038/280746a0 en Volcanic resurfacing rates and implications for volatiles on Io article