During periods of southward interplanetary field and basically constant dynamic pressure, the magnetopause can move earthward due to the so-called phenomenon of magnetopause erosion. In this study, we present several erosion events monitored at geostationary orbit by the GOES spacecrafts underlaying WIND measurements in the solar wind. We selected a number of events using 4 years of WIND observations (1996-1999). Specific selection criteria are based on obtaining a progressively decreasing IMF B_z negative, to have various levels of erosion, with and without dynamic pressure changes and of different durations in time. To figure out the erosion effect on geostationary orbit, we have to compare the measured depression in the geostationary magnetic field strength with the magnetic field strength on the well known May 11, 1999, the day the solar wind almost disappeared.