David on Formosa

A report in The Guardian yesterday suggests that Taipei 101, the world's tallest building, may be causing earthquakes.

Taipei 101 is a building with a lot to boast about. Standing 508 metres (1,667ft) high, it is the world's tallest. And at 700,000 tonnes, it must be among the heaviest. But the sheer size of the Taiwan skyscraper has raised unexpected concerns that may have far-reaching implications for the construction of other buildings and man-made megastructures. Taipei 101 is thought to have triggered two recent earthquakes because of the stress that it exerts on the ground beneath it. According to the geologist Cheng Horng Lin, from the National Taiwan Normal University, the stress from the skyscraper may have reopened an ancient earthquake fault. If he is right, then it raises concerns about proposals such as Sky City 1000 in Japan, the vertical city that has been proposed to solve Tokyo's housing problems. And it is not just skyscrapers that are a problem. Dams and underground waste deposits may also cause rumblings if they become too large.

Cheng's claims were published as a paper in in the journal Geophysical Research Letters. However, some other experts are sceptical about the claims.

"A building will change the stress on the ground under the building, but this probably won't reach down to around 10km, the level where the earthquakes occurred," says John Vidale, an earthquake expert at the University of California in Los Angeles. Zygmunt Lubkowski, an earthquake analyst for the engineering firm Arup, is concerned at the lack of data. "Earthquakes occur on timescales of thousands to millions of years. From just 10 years of earthquake data it is hard to tell if the extra earthquakes are just noise in the signal or due to the building."

Whether Taipei 101 causes earthquakes or not it dominates Taipei's skyline. The next tallest building, Shinkong Mitsukoshi, is less than half its height at 244 metres. Taipei 101 has the world's fastest elevators. A 606 tonne steel ball is suspended from the 92nd floor. The ball acts as a stabiliser to prevent the building swaying excessively in earthquakes or strong winds. The building's unique design is inspired by bamboo and traditional Chinese architecture.