Rockall part of the deeply eroded Rockall Igneous Centre that was formed as part of the North Atlantic Igneous Province, approximately 55 million years ago, when the ancient continent of Laurasia was split apart by plate tectonics. Greenland and Europe separated and the northeast Atlantic Ocean was formed between them, eventually leaving Rockall as an isolated islet. The RV "Celtic Explorer" surveyed the Rockall Bank in 2003. The Irish Light Vessel "Granuaile" (the same name as the steamer on the RIA 1896 botany survey) was chartered by the Geological Survey of Ireland, on behalf of the Department of Communications, Marine and
Rockall Basin (also known as the "Hatton Rockall Basin"). In 1956 the British scientist James Fisher referred to the island as "the most isolated small rock in the oceans of the world". The neighbouring Hasselwood Rock and several other pinnacles of the surrounding Helen's Reef are smaller, at half the size of Rockall or less, and equally remote, but those formations are legally not islands or points on land, as they are often submerged completely, only revealed momentarily above certain types of ocean surface waves. Rockall is about wide and long at its base and rises sheer to a height of