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cnrs I international w 28 | In Images magazine Geophysics Exposed to rising sea levels, the Vanuatu archipelago often illustrates the risks associated with climate change. Its exceptional characteristics also make it an ideal laboratory for studying terrestrial dynamics and seismic phenomena. Sinking Feeling in Vanuatu BY Mathieu Grousson East of Australia, in the Pacific Ocean, lies an archipelago of 83 islands called Vanuatu. This island nation grabbed headlines in 2004 when the village of Lataw in the Torres Islands had to be moved away from the shore to avoid rising sea levels. Lataw was flagged as one of the first communities in the world forced out by climate change. Yet in 2011, French scientists revealed that global warming was not the only cause for rising waters: the island was also sinking due to tectonic motions.1 Sitting at the boundary between the Pacific and Australian tectonic plates, this exceptional geophysical site is affected by a phenomenon known as locked subduction. “The Australian plate is creeping under the Pacific plate, but submarine seamounts at this location partially impede its motion,” explains Valérie Ballu, who—together with her colleagues at 01 The Vanuatu archipelago—a group of islands in the Pacific Ocean—is exposed to a number of geophysical hazards, making it a key strategic research site. 02 A plantation devastated by the sea in the Torres Islands. Although the damage was partly due to rising sea levels, it was mainly caused by the sinking of the islands. 03 While in Vanuatu, the IPGP and IRD researchers set up a large number of seismic stations across the archipelago. 04 This buried seismometer is part of the data acquisition station of the GEOSCO PE global seismic network. The data is transmitted in real time via Internet. The device can also be remotely controlled. 01 02 © Campagne GE ODEVA/IRD-CNRS


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