Satellite altimeter observations of sea surface height show an extensive region of long wavelength fluctuations in the Indian sector of the Southern Ocean. A previous study showed that a similar feature found in the South Pacific is due to a trapped geostrophic mode of the ocean. Here we investigate the feature in the Indian sector and find that it is due to a similar mode with a decay time of approximately 3.5 days. These previously unsuspected large scale modes of the ocean will have a significant effect locally on the satellite based gravity measurements currently underway.