Biggest skyscraper - causing earthquakes?
This fantastic picture, from www.kathrein.de, is of Taipei 1, a skyscraper 1,667 feet high, weighing 700,000 tons. I saw this story at Science and Politics.
Skyscraper that may cause earthquakes
by Kate Ravilious, Friday December 2, 2005, The Guardian
The sheer size of the Taiwan skyscraper has raised unexpected concerns ... 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.
Before the construction of Taipei 101, the Taipei basin was a very stable area with no active earthquake faults at the surface.
However, once Taipei 101 started to rise from the ground, things changed. "The number of earthquakes increased to around two micro-earthquakes per year during the construction period (1997 to 2003)... Since the construction finished there have been two larger earthquakes (magnitude 3.8 and 3.2) directly beneath Taipei 101, which were big enough to feel," says Lin.
Many engineers and scientists are more perturbed about the impact of other types of construction. "It is well known that man can induce earthquakes from things like mining, building reservoirs and extracting oil and gas, where a large load acts over a large area."
One of the most convincing examples is the Koyna Dam earthquake, which occurred in 1967. More than 120 people died and many more were injured when a magnitude 6.5 earthquake shook the ground around the recently constructed dam in Maharashtra state, India.
In 1967, mountains of waste that had been injected into the Rocky Mountains set off a magnitude 5.5 earthquake under Denver in Colorado. A similar earthquake under a nuclear waste store would be disastrous.
Meanwhile, the idea of carbon sequestration - reducing global warming by locking up carbon dioxide in holes underground, will be pointless if earthquakes let all the carbon dioxide escape.
"Huge amounts of fluid are going to be put in large cavities and earthquakes are a real concern," says Leonardo Seeber, a geologist from the Lamont Doherty Earth Observatory in New York. "I am less worried about nuclear waste as it is more likely to be put in a small tunnels rather than huge cavities," he adds.
Technorati Tags: Ecology, Environment, Earth, Earthquake, Architecture, City, Sequestration