New land

Those maps of the Earth look terribly solid, but don't be fooled. Just as Belarus or Eritrea can appear from something that was once labelled the Union of Soviet Socialist Republics or Ethiopia, new land can spring forth from the sea. In a volcanic chain such as Hawaii, new islands are created first as lumps of lava at the sea floor. They then break the surface and stay there until they are eroded away again and become seamounts. But a look at the recent development of Iceland shows that nature does not always follow this stately process with a timescale of tens of thousands of years.

Take the island of Surtsey. It appeared off the south-west coast of Iceland, just beyond a long-established island called Heimaey, between 1963 and 1967. Now it rises to 174m above sea level, slightly less than when it first formed as the material that comprises it has compacted. Its total volume is about a cubic kilometre, of which 90 percent is below sea level. It is named after a Norse fire god.

Six years later, Heimaey itself was nearly destroyed as a human habitation by lava that threatened to cut off its harbour. It was saved by a lone enthusiast, and then the population at large, hosing the lava to cool it and stop it in its tracks.

Nor do new islands have to be natural.The 4 million tonnes of rubbish dumped in Tokyo Bay every year have already created about 250 hectares of new “land” there. There have been plans for a 30,000 hectare island in Tokyo Bay, to provide space and use up waste, although the Japanese economy would need more confidence than it has today (in 2006) for this to happen. Kobe, also in Japan, already has the artificial Port Island, so Tokyo may feel the need to compete.