Pacific Island Atolls: Evolution and Destruction
4.18 Earth Science Synthesis - Stuart Fordyce
The islands of the Pacific Ocean show a distinct morphological evolution over time. This evolution is initiated by magmatism, as the Pacific tectonic plate interacts with underlying mantle-influenced hotspots. The evolution of the volcanic island results in carbonate reefs forming in the warm-nutrient rich waters around the islands. The subsequent erosion of the volcanic core, and the carbonate reef, is driven by tectonic subsidence and weathering processes.

This webpage aims to describe and illustrate the processes by which volcanism initiates the evolution of islands, and the following carbonate reef formation. The destruction of the islands by erosion and subsidence will also be analysed. This issue has wider implication than a purely geological case study: many of the islands are inhabitant, forming some of the world's smallest countries, and their people may become homeless with a rise in sea level resulting from climate change.

Finally, the geographical remoteness of the Pacific Islands led to their use as a nuclear weapon testing area throughout the 'Cold War' in the late 20th Century. This has led to local environmental problems, which will affect the wider Pacific Ocean for thousands, if not millions of years to come
Image of Aitutaki Atoll, Cook Islands. Image courtesy of www.visitaitutaki.com
Hotspots and Volcanism
Evolution of Reefs
Subsidence and Weathering
Hosted by www.Geocities.ws

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