DHARAMSHALA, June 12: Minor but frequent earthquakes have been jolting the Pakshoe region in eastern Tibet for nearly a year now, prompting the locals to blame China’s unchecked mining in the region.
“Almost for an entire year now, we have been living in earthquake trauma and many of us are spending our nights outside our houses,” Tenpa, a local resident told Phayul over phone recently.
According to locals, the tremors started after years of Chinese coal mining in the region.
“As far as our elders can remember, such frequent earthquakes haven’t troubled our region,” Tenpa said. “We have good reason to believe that the earthquakes are a result of years and years of unchecked mining by China, hollowing our mountains and borrowing deep inside the earth.”
A look at the US Geological Survey records show that earthquakes measuring 3.0 to 4.0 on the richter scale have quite frequently struck the region.
Although no major destruction or immediate casualties have so far been reported but the same source told Phayul that some of houses in the region have suffered minor cracks in recent months.
“Pakshoe is a weak crustal zone prone to earthquake as it falls between two fault lines,” Tsering Dhondup, a researcher at the Environment and Development Desk of the Central Tibetan Administration said. “Large scale exploration and too much mining of course run the risk of destabilising the region.”
Man-made quakes have been a topic of wide discussion following speculations that mining and drilling activities triggered the devastating 7.0 magnitude earthquake in Haiti in 2010, a region which had not witnessed an earthquake for over two centuries.
Christian Klose, a researcher at Columbia University, who studies man-made quake, in an extensive study, has said that drilling into the earth to mine for gas, oil and minerals and constructing massive dams have caused “at least 200 quakes of more than 4.5 magnitude in the past 160 years.”
The best-known cases of man-made quakes, according to Klose’s research, include the 7.9-magnitude quake that killed nearly 80,000 people in China’s Sichuan province in 2008 and the magnitude-5.6 quake that struck Newcastle in New South Wales in 1989 that caused 3.5 billion U.S. dollars worth of damage.
Klose notes that the Zipingpu Dam in Sichuan, with nearly 320 million tons of water pressing down on a fault line, contributed enough stress to trigger the quake through a process called impoundment. “If you push your finger on top of a paper plate, the plate will bend. That same effect works on all the tectonic plates on the Earth’s crust,” the research concluded.
The Newcastle quake, according to Klose, was triggered by changes in tectonic forces caused by years of removal of millions of tons of coal from the area and the groundwater pumping needed to keep the mines from flooding.
"For each ton of coal produced, 4.3 times more water was extracted," Klose said.