Photo Gallery: Rising Seas or Sinking Islands?

Foto: Gerald Traufetter / DER SPIEGEL

Climate Change or Tectonic Shifts? The Mystery of the Sinking South Pacific Islands

Environmentalist organizations have used images from South Pacific islands to illustrate the disastrous effects of rising sea levels. But a group of French researchers has found that the problem is much more complicated: The islands are also being pulled under by shifting tectonic plates.

The island rises out of the ocean like a crenellated fortress. The trees on its slopes stand so close, their crowns so impenetrable, that the island appears to be wrapped in a blanket of green velvet.

Below, palm trees line the beach and the shapes of huts, some emitting smoke, stand out against the blinding light of the rising sun.

A team of French researchers steer their motorboat carefully through the reef toward Vanikoro, this fleck of earth that's part of the Solomon Islands, in the South Pacific. They've come here to uncover the island's secrets. "It feels is if we were on an expedition 250 years ago," says Valérie Ballu, 44, a geodesist from Paris. Geodesy is the science of measuring the Earth.

Ballu jumps into the shallow water of a sandbank, then pushes the boat ahead of her. The village on the shore is now showing signs of life. Women in brightly colored skirts appear at the entrances to their huts, babies in their arms. Naked, curious children with frizzy blonde hair run down to the edge of the beach, while men in dugout canoes paddle out to meet their foreign guests.

In less than a stone's throw, two cultures will meet, two different ways of living and thinking. Friendly laughter makes for a good start in easing this initial encounter.

"Momombo wako!" calls Alexandre François, 40, the French group's linguist. He has already lived on the island and studied its languages. The men from Vanikoro recognize him. They call him "the white man from the big island."

These foreign visitors are here because Vanikoro is slowly sinking into the ocean -- or at least that's what they believe. From their boat, the team begins unloading a number of heavy instruments with which they plan to measure the island.

Vanikoro has an area of less than 200 square kilometers (77 square miles), which makes it a bit smaller than Martha's Vineyard. Its 900 residents live without electricity, telephones or regular ferry service. The horizon gives off the impression of standing at the end of the world, and the only way to get away from this place is with a long pirogue, a dugout canoe outfitted with a sail.

The island's inhabitants divide Vanikoro roughly into three tribal areas, and they speak four different languages. Vanikoro lies more than 2,000 kilometers (1,200 miles) northeast of Australia and, like many of Oceania's islands, was created by volcanic activity, its destiny determined by the rubbing and colliding of continental plates. The researchers from France's National Center for Scientific Research (CNRS) plan to spend two days investigating this geological spectacle.

A Tiny Island with Global Significance

The first day begins with a disappointment: When Ballu and her team set out to find the location where they measured the island's elevation seven years ago, they discover that their most important survey marker, originally placed a safe distance from the beach, is now underwater, with the sea eroding the metal piece and its concrete base. "That's probably caused it to slide down," remarks geologist Stephane Calmant, 52, who fears this renders the marker "useless."

Still, this development offers proof of at least one thing: that the coast here is in motion. But the question remains: Is the sea level rising, or is the island sinking? "The questions we're trying to answer here on Vanikoro have global significance," Ballu says.

Indeed, since water levels are rising faster around the islands of the South Pacific than anywhere else on Earth, the region has become an important object of study for oceanographers, climate researchers and geologists. At the same time, it draws the attention of politicians and ecologists to these remote islands.

Not far south of Vanikoro, the island of Tegua is home to the people the United Nations declared the world's "first climate change refugees" in 2005. On Tegua, part of the island nation of Vanuatu, an entire village had to relocate due to rising water levels, and global media publicized photographs of a coconut plantation submerged in water, reclaimed by the sea.

That village relocation on Tegua "underlines the increasingly drastic measures now underway to conserve low-lying communities as a result of the rise in human-made emissions to the atmosphere," the United Nations Environment Programme (UNEP) warned at the time. Klaus Töpfer, a German politician with Chancellor Angela Merkel's center-right Christian Democratic Party (CDU) and the UNEP's executive director at the time, bleakly noted: "The melting and receding of sea ice and the rising of sea levels, storms surges and the like are the first manifestations of big changes underway which eventually will touch everyone on the planet."

A Battle for Every Millimeter

But does the fate of the village on Tegua really lend itself to being held up as a symptom of global warming? The researchers from France have their doubts, and they're here on Vanikoro to look for evidence.

Their first tool is a machete. Valérie Ballu is now looking for the second survey marker. Her colleague Alain Le Breüs pulls out hand-drawn sketches resembling a treasure map. But without even needing to look at the map, Alek Silo, a local, points a bony hand toward a young mango tree.

And, indeed, the researchers find their survey marker there under the bushes. They quickly unfold a yellow-and-red tripod of the kind land surveyors use. "Now the battle for every millimeter begins," Ballu says.

She checks the position of the GPS antenna, then asks Alek to cut down a couple of young trees that are interfering with reception. "We need signals from as many GPS satellites as possible for our measurements," Ballu explains. "That increases our accuracy." The display on her GPS device ultimately indicates contact with 16 satellites.

These devices will store position data from satellites every 30 seconds for 48 hours. "The longer we measure, the more precise the results," Ballu says.

Determining the minute motions of the Earth's crust down to the millimeter is no easy task. The planet is not a rigid sphere. Instead, it is constantly reshaped by the force of gravity exerted by the moon and sun as well as by other planets, such as Mars and Jupiter.

Those bodies tug not only at the Earth's surface, but also on the GPS satellites, creating discrepancies in their orbits. "All these things cause a loss of precision," Ballu explains.

The scientist climbs across two tree trunks spanning a boggy stream and heads back down to the beach. Calmant, the geologist, is pacing the beach with a GPS device in order to compare the results with previous sketches. Le Breüs points to tree roots rotting in the water and says: "On my first visit, the coast ran along behind there."

Le Breüs has been to Vanikoro several times, but his previous visits were for a different reason. "We're standing on historical ground," he says, pointing out a memorial stone bearing a bronze plaque. This beach, he explains, is where explorer Jean-François de Lapérouse's courageous crew of sailors took refuge when their ships sank on the reef surrounding the island.

The two ships set sail shortly before the French Revolution, dispatched by France's beleaguered regent, Louis XVI. In 1788, they had been at sea in the Pacific for two years when Lapérouse, ill with scurvy, found himself in the middle of a cyclone. "By the time the men spotted the island in the frothing sea, it was too late," Le Breüs says. "They were already too close to the reef."

The fate of Lapérouse's men captivated all of Europe in the early 19th century, and the shipwreck earned the small island of Vanikoro a mention in world literature. "Ah, what a splendid death for a seaman!" exclaims Captain Nemo, the hero of Jules Verne's 1870 novel "20,000 Leagues Under the Sea," when he dives down to the wreck.

Le Breüs was there when archeologists came and salvaged anchors and glasses. On the beach, they found coins, chinaware and a skull they were able to identify as belonging to a scientist who had been aboard the ship. Now a GPS device stands at the site of that tragedy, recording data.

A climate-change report to be published next year will present evidence that the world's oceans will rise between 0.5 and 1.2 meters (1.5 and four feet) by 2100, with global warming already increasing sea levels by 1.8 millimeters (0.07 inches) a year. However, that amount is not much when compared to the natural fluctuations at work here. Like most inhabitants of the South Pacific, those of Vanikoro must contend with sea-level fluctuations of some 20 centimeters (eight inches) caused by currents in the Pacific, such as the climate phenomenon called El Niño.

A Language's Lone Survivor

Ballu is in a hurry. Her team has less than 48 hours to determine whether other parts of the island's coastline are disappearing as well, and they have plans to visit the village of Temuo on the eastern side of the island. After lunch on their research ship Alis, operated by France's IRD institute for development research, they once again lower their motorboat into the water.

On their way, the research team is caught in a tropical rain shower. Then they come upon a beach where they can see coconut palms with their roots exposed by the water through a steaming veil of rain. Are these the initial signs that the island is sinking, or that the sea level is rising?

Ballu's team receives an eager reception from the villagers. She wants to talk to them to learn more about the ocean's behavior, with the help of François, the linguist. François, however, quickly becomes captivated by what he later describes as "a linguist's finest hour," which arrives in the form of a man with a faded Nike T-shirt, sparse hair, high cheekbones and a flat nose -- Lainol Nalo, the village chieftain.

"Mamabo apika," Alexandre François says in greeting.

"Mamabo apika," Lainol replies.

"That's Tanema!" François cries excitedly. He doesn't know much more of this language than the greeting he's just uttered, and if he wants to learn it, Lainol is the only person on the planet who can still teach him.

François digs out his digital recorder and plays back a voice for Lainol, a voice the man knows very well -- his grandmother's. She died last year at the age of 105, and she spoke Tanema, as well.

On his last visit to Vanikoro, François recorded the centenarian telling him a story. Now he'd like to have the story translated. "That way, I can get a sense not only of the vocabulary, but also of the language's syntax and structure," he explains.

A Unique Laboratory for Languages

Language is more than just a means of communication. "It's also a form of memory," François says, and it's full of knowledge about the island, the plants that grow here and the laws of the ocean. "When the last speaker of a language dies, he or she takes all of that knowledge and all of those stories to the grave."

The islands of the South Pacific, in particular, prove to be a unique laboratory for languages. Although just 0.1 percent of the world's population lives here, the region is home to 1,250, or 18 percent, of its languages. "What stands out is their unequal distribution," François says.

Two different ethnic groups inhabit these islands, Polynesians and Melanesians. Both groups are descended from the Lapita, a culture that set out around 3,000 years ago to explore the Pacific. Both modern-day populations have dark skin, but Melanesians' facial features bear more of a resemblance to Africans, while Polynesians look more Asian.

The two groups also have very different ways of life. The Polynesians have remained a seafaring people like their ancient ancestors, navigating by the stars and sensing the ocean's currents with their hands. François has catalogued over 25 names for types of wind and more than 100 nautical terms used by Polynesians.

The Melanesians, on the other hand, who make up the majority population on Vanikoro, discovered agriculture and developed the multitude of languages that François regards as his life's work to decipher.

Lainol, the tribal leader, believes he knows the reason for this diversity of languages. "If we have our own words, people from another village won't understand us," he explains, adding that he considers this a strategic advantage.

"They made a conscious decision to distinguish their language from those in other villages," François says.

An Island Dragged into the Sea

While the linguist is hunting down the vocabulary of a dying language, a young man draws Ballu into conversation. His new polo shirt and neat trousers set him apart from the island's residents in their faded shirts, most of which come from used-clothes donations from around the globe.

The man introduces himself in English as Michael Meninga, 38, a teacher sent here for three years from Lata, the capital of Temotu Province. He asks Ballu if she would be willing to talk to his students about her research.

Meninga pulls out a new laptop, which seems like an alien object from another age in this traditional village. Back at his roughly hewn teacher's desk, he hooks up the computer to a car battery he's charged with a solar panel, bringing the PowerPoint culture of modern academia on a collision course with the local people's beliefs in ghosts and evil forces.

Using the particular variant of pidgin English spoken here, Ballu starts to explain about the planet's hot core and the continental plates that drift across molten rock. She talks about "big fella earth sec sec," meaning the earthquakes that everyone here knows well.

Right under their feet, she explains beneath the palm frond roof of Temuo's village school, one plate is slipping under another. Ballu splays her hand to represent the Australian Plate disappearing under the Pacific. "No soap soap," Ballu adds, jerking her left hand -- the plates snag against one another and the built-up pressure is released.

Earthquakes and tsunamis strike Vanikoro regularly, but people here are at the mercy of the forces of nature in a longer-term way, as well: On its slowly sinking course, the Australian Plate is dragging Vanikoro along into the depths.

Ballu was able to document that this is the case for the nearby island of Tegua in a well-received publication last year. That island sank nearly 12 centimeters (five inches) between 1997 and 2009, to the point that the coconut plantation now famous at global climate conferences was underwater. "The sea level rose, but three quarters of that was caused by the land's subsiding," she explains.

Mislead by Missionaries

That the UN had been premature in declaring the villagers on Tegua to be climate change refugees became clear when a large earthquake caused the island to shoot back out of the water in 2009. "The coconut plantation has been on dry land since then," Ballu says.

However, she points out that, for the people there, it doesn't much matter which specific physical phenomena forced them to abandon their village. What frustrates Ballu is that a climate-change adaptation fund helped them resettle in a new village, but in a location hardly better than the original one. "It's at a lower elevation," Ballu says. "Spring tides or tsunamis can still reach it."

At the village school, Ballu looks around and senses her audience is no longer following her, so she asks a more specific question: "Why do you think earthquakes happen?" At first, no one dares to speak. Then a young woman, presumably an assistant teacher, ventures an answer. Her mouth is bright red from the betel nuts she chews, as most residents of Vanikoro do, and she describes a man, a dark magician, possessed by evil spirits. "The earthquakes are his fault," she says.

A belief in spirits survives on Vanikoro to this day. Although scientists have a hard time accepting them, it was precisely these superstitions that once protected people from the forces of nature. As one elderly man explains: "The missionaries said: 'Now you believe in Jesus; now you don't need to be afraid.'" But the results were disastrous: The people moved down from the island's slopes and closer to the sea.

That same sea is steadily encroaching. Ballu's GPS devices indicate Vanikoro is sinking by seven millimeters (0.3 inches) a year.

Translated from the German by Ella Ornstein
Die Wiedergabe wurde unterbrochen.