Five ways for humans to trigger a natural disaster
large dam was built and its reservoir filled, a magnitude 7.5 quake struck the area killing 200 people and injuring thousands more. Since then, the region has experienced frequent earthquakes. “People often ask whether nuclear testing can generate earthquakes,” says Booth. “The answer is no.” This is because, unlike dams, nuclear explosions produce instantaneous and short-lived geological stresses. As the wave of pressure moves through the rocks, the particles inside them shake but quickly go back to their original position.
* Disappearing lakes: In addition to erupting and furiously shaking, the earth can be made to consume entire lakes. On 20 November 1980 Lake Peigneur in Louisiana was sucked into the ground in an enormous whirlpool. Although the exact cause of the incident is difficult to ascertain as the evidence was washed away, it is generally believed that the lake’s plug was pulled when a Texaco oil rig drilled into a salt mine directly beneath the lake. This caused water to pour into the mine, filling the shafts and dissolving the salt, as the oil rig and eleven barges were sucked down. The event is said to have looked like a giant bathtub emptying down a drain. Incredibly, no-one was hurt. But the lake’s ecosystem was permanently altered. Just days after the event, water flowed backwards from the Gulf of Mexico into Lake Peigneur, turning the freshwater lake into a brackish, saltwater one.
* Flooding: Cloud-seeding is an increasingly common form of weather modification — but is it possible to push the method one step too far and bring on a biblical flood? On 9 June 1972 more than 35 centimetres of water — nearly a year’s worth of rain — fell in six hours over the Black Hills of Western South Dakota. The rainfall caused Rapid Creek to overflow and the Canyon Lake Dam to burst, resulting in huge floods in downstream Rapid City. More than 200 people died and 3000 were injured. About 1300 houses were destroyed, some simply lifted by the water and carried away. In all, the floods caused over $160 million in damage to the city. On the day of the storm, scientists had been carrying out cloud-seeding experiments nearby, and were later blamed for the floods.
The principle of cloud seeding is relatively simple. The skies are peppered with a chemical — usually silver iodide — which draws the moisture out of
