In the days after the devastating Nepal earthquake in April, geologists debated whether or not the Earth’s violent shaking had changed the height of Mount Everest. Some initial reports suggested the world’s tallest mountain might have grown, or shrunk, by several feet, although those numbers were quickly revised down to a mere inches.
On Monday, Chinese scientists announced that the magnitude-7.8 quake shifted Everest about 1.2 inches (3 centimeters) southwest but did not change the height of the 29,029-foot (8,848-meter) mountain.
Scientists in the United States, Europe, and China have been studying the question since the quake and a consensus seems to be emerging that the mountain’s height was largely unaffected. Beyond updating almanacs, the goal of the research has been better understanding how the planet’s plates are moving and improving the ability to forecast earthquakes.
The April quake reversed the usual direction of the mountain, returning it to roughly where it had been nine months earlier, the Chinese report says.
China's conclusions comes from data from a satellite mapping receiver the scientists installed on Everest in 2005. In the decade since, the mountain has drifted northeast at the rate of about 1.6 inches (4 centimeters) a year and grown about 0.1 inches (0.3 centimeters) taller annually.
Nepal is "one of the most seismically hazardous regions on Earth,” according to the U.S. Geological Survey. The April temblor was caused by a sudden thrust, or release of built-up tension, along the major fault line where the plate carrying India is slowly diving underneath the one carrying much of Europe and Asia. It is that force that formed the Himalaya in the first place and which continues to drive their growth toward the sky.
The city of Kathmandu, which was closer to the epicenter of the quake than Everest and was heavily damaged, saw more dramatic movement of as much as a meter (three feet).