By Alice Klein

With acknowledgements to the New Scientist:

“At least eight low-lying islands in the Pacific Ocean have disappeared under rising seas.

Sea levels are currently climbing by an average of 3 millimetres per year around the world due to climate change. But they are creeping up even faster in the western Pacific, where a natural trade wind cycle has caused an extra build-up of water over the last half-century.

In Micronesia and the Solomon Islands, which lie in the western Pacific, sea levels have risen by up to 12 millimetres per year since the early 1990s.

In 2016, a study led by Simon Albert at the University of Queensland in Australia found that five of the Solomon Islands had been lost since the mid-20th century.

Now, Patrick Nunn at the University of the Sunshine Coast in Australia has observed a similar phenomenon in Micronesia.

Miniature Atlantises

His team conducted coastal surveys, spoke to local people and reviewed satellite images for the island of Pohnpei and several low-lying islands scattered throughout the surrounding reef.

Pohnpei shows surprisingly little coastal erosion, probably because it is relatively high above sea level and ringed by mangrove forest, says Nunn. “Mangroves provide a buffer by absorbing wave energy and trapping sediment,” he says.

 Three small islands on the west side are also well-preserved, possibly because they are sheltered from strong winds and waves by the main island, says Nunn. A nearby coral atoll – Ant Atoll – also has very little erosion, which is probably because an adjacent lagoon acts like a sediment trap.

However, several of the other low-lying reef islands – mostly to the south of the main island – have shrunk considerably or disappeared entirely.

Lost to the waves

And some islands have disappeared entirely. Local people told the researchers about two former islands called Kepidau en Pehleng and Nahlapenlohd – the latter of which was famous for hosting a great battle between warring chiefdoms in 1850. Both appear to have vanished within the last century.

Aerial images revealed that another six low-lying islands – in the unpopulated Laiap, Nahtik and Ros island chains – became submerged between 2007 and 2014. Each was about 100 square metres.

These changes in Micronesia are a preview for other low-lying nations around the world, says Nunn. As sea levels continue to rise, many inhabitants will be forced to move to higher ground, he says. This is already happening in the low-lying Carteret Islands of Papua New Guinea, where a resettlement scheme is underway to move the population to Bougainville – a higher island 90 kilometres away.

However, one positive finding from the Micronesia study and others is that not all low-lying islands are destroyed by rising seas, says Albert. Islands that are sheltered, or have mangrove forests or lagoons for trapping sediment, appear to have good resilience, he says.

“These are the first places on Earth to experience really high rates of sea level rise, so they give great insights into what can happen,” says Albert. “But we’re finding there’s a large diversity of responses – not every island will erode.”

Understanding why will help us plan our response as seas rise around the world.”

Journal reference: Journal of Coastal ConservationDOI: 10.1007/s11852-017-0531-7

25th October 2018:

And here is a Quartz News report an another Pacific islands lost to the waves:

“East Island is gone.

The 11-acre island roughly 400 miles northwest from the Hawaiian island chain was wiped off the map after a powerful Pacific hurricane swept through the region earlier this month, Honolulu Civil Beat reported.

The island, part of a chain of small islands called the French Frigate Shoals, was a critically important habitat for one of the cutest and most endangered seals on the planet: The Hawaiian monk seal.

monk seal

There are only about 1,400 Hawaiian monk seals left in the wild. To give you an idea of how precarious their existence is, roughly 30% of the monk seals alive are alive “due to direct life-saving interventions,” according to the US National Oceanic and Atmospheric Administration. In a typical year, 30% of monk seal pups are born on East Island, Civil Beat noted.

East Island was also the single most important nesting site for the Hawaiian green sea turtle, another imperiled species. The French Frigate Shoals serve as nesting ground for 96% of the Hawaiian green sea turtle population, and approximately half lay their eggs at East Island, Charles Littnan, a conservation biologist with NOAA, told Civil Beat. NOAA scientists estimate that 19% of this year’s nests on East Island had not yet hatched and were swept away by the storm, the Huffington Post reports.

Hurricane Walaka, which wiped out the island, was one of the strongest Pacific Ocean storms in recorded history. As the New Republic notes, its rapid intensification from a 40 mph storm to a 120 mph hurricane in just 30 hours is consistent with the effects of climate change—storms passing over hotter-than-average seas intensify far faster.”