Sizing Up Pacific Atolls

Professor Paul Kench of Auckland University’s environment school and coastal process expert Dr Arthur Webb of the Fiji-based South Pacific Applied Geoscience Commission have found that despite rising sea levels some Pacific Island coral atolls have actually increased in size over the past 6 years. The reason: Coral islands respond to changes in weather patterns and climate, with coral debris eroded from encircling reefs pushed up onto the islands’ coasts by winds and waves. Kench and Webb used historical aerial photographs and high-resolution satellite images to study changes in the land area of the islands. While four of the 27 islands studied had gotten smaller, the other 23 had either stayed the same or grown bigger, according to the research published in the scientific journal Global and Planetary Change. Kench said it had been assumed that islands would “sit there and drown” as sea levels rise. But as the sea rises, the islands respond. “They’re not all growing, they’re changing. They’ve always changed … but the consistency [with which] some of them have grown is a little surprising,” Kench said.