The Indo-Australian Plate was a major tectonic plate that included the continent of Australia and surrounding ocean, and extended northwest to include the Indian subcontinent and adjacent waters. It was formed by the fusion of Indian and Australian plates 43 million years ago. Recent studies, and seismic events such as the 2012 Indian Ocean earthquakes, suggest that the Indo-Australian Plate has broken up into two or three separate plates due primarily to stresses induced by the collision of the Indo-Australian Plate with Eurasia along the Himalayas, and that the Indian Plate and Australian Plate have been separate since at least .