Coral islands bigger despite ocean's rise

Some South Pacific coral atolls have held their own or even grown in size over the past 60 years despite rising sea levels says new research.

Scientists worry that many of the tiny low-lying islands in the South Pacific will vanish under rising seas. But two researchers who measured 27 islands where local sea levels have risen 4.8in – an average of 0.08in per year – over the past 60 years, found just four had diminished in size. This is because coral islands respond to changes in weather patterns and climate, with coral debris eroded from encircling reefs pushed up on to the islands' coasts by wind and waves. Professor Paul Kench of Auckland University's environment school, and Arthur Webb of the Fiji-based South Pacific Applied Geoscience Commission, used historical aerial photographs and satellite images to study changes in the islands' land area.

While four were smaller, the other 23 had stayed the same or grown, according to the research, published in Global and Planetary Change.