Researchers found some Tuvalu’s islands to grow in size instead of sinking as sea levels rise
Tuvalu has long been marked as a prime candidate to get swallowed up by the ocean as sea levels rise, but new research shows the land mass of the nation is actually expanding.
That’s based on aerial photographs and satellite imagery taken of Tuvalu’s nine atolls and 101 reef islands between the years 1971 and 2014. Researchers found eight of the atolls and nearly three-quarters of the islands grew in size in that time, Science Alert reports.
Overall, the land area increase was 2.9 percent, even while recorded sea levels rose around the coasts of the country. The team from the University of Auckland in New Zealand says we may have to rethink how many island nations like Tuvalu are likely to disappear.
“We tend to think of Pacific atolls as static landforms that will simply be inundated as sea levels rise, but there is growing evidence these islands are geologically dynamic and are constantly changing,” says one of the researchers, Paul Kench.
“The study findings may seem counterintuitive, given that [the] sea level has been rising in the region over the past half century, but the dominant mode of change over that time on Tuvalu has been expansion, not erosion.”
So with sea levels around Tuvalu rising at twice the global average over the study period – about 4 millimetres or 0.16 inches every year – how is the land mass expanding at the same time?
The researchers say wave patterns shifting sediment, sand, and gravel around, plus material dumped by storms, could be offsetting coastal erosion.
The team also suggests that while climate change is still very much a threat to the existence of atoll nations, their inhabitants can still plan for a long-term future, perhaps by focusing community development on the larger islands that are less under threat.
The researchers also write in their published paper that the people of Tuvalu will still need to adapt to survive – it’s not going to be enough just to sit back and hope that the island land mass keeps expanding.
That said, the study does suggest that inhabitants in Tuvalu and other similar island nations may have more time than they realise, and might not necessarily have to migrate long distances and abandon their homes to avoid the rising tides.
“On the basis of this research we project a markedly different trajectory for Tuvalu’s islands over the next century than is commonly envisaged,” says Kench.