MOUNT EVEREST? NOT SO HIGH.
Amid speculation Nepal’s deadly 2015 earthquake might have caused Mount Everest to shrink, India is dispatching an expedition to the summit to confirm whether the world’s highest mountain is indeed still 8,848 metres.
“We are remeasuring it,” India’s surveyor general, Swarna Subba Rao, told Indian media outside a geospatial forum this week.
He added, “there is a doubt in the scientific community that it is shrinking.”
India and Nepal both note Everest’s official height as 8,848 metres, a figure first obtained by Indian surveyors in 1955 — two years after the mountain was first summited by Edmund Hillary and Tenzing Norgay.
However, satellite data collected after a 7.8-magnitude earthquake struck Nepal in April 2015 showed the mountain was 2.8 centimetres smaller. UNAVCO, a non-profit geoscience research consortium, suggested the cause was a relief of strain in the Earth’s crust. The force of the shaking is also believed to have shifted the Nepalese capital of Kathmandu several metres to the south. The quake killed 9,000 people and extensively damaged the city.
The true height of the famed peak has long been in dispute.
A 1975 Chinese expedition found that the mountain was 8,848.13 metres. A second Chinese expedition in 2005 placed a beacon at the peak that calculated the height at 8,844.43 metres.
In 1999, a U. S. team dubbed Everest-Millennium anchored a GPS unit to the mountain’s peak, which found the height to be 8,850 metres — three metres taller than the India-measured height.
The discrepancies are partly due to surveyors measuring the buildup of ice and snow, rather than the mountain’s true “rock height.”
Mount Everest may also be going up or down with the movement of the Earth. The tectonic forces that created the Himalayas are constantly causing the landscape to shift.
The upcoming Indian survey, which will comprise five members setting out as early as March, will use a combination of both high and low-tech methods to get a reading.
First, a team of climbers will place a GPS tracker at the summit.
Second, surveyors will use the old-fashioned method of triangulation. Scientists will use instruments to sight the peak from a known distance, and then calculate its height based on the angle of their observation.
It was a 19th century triangulation, in fact, that first established Mount Everest as the world’s highest peak at 29,002 feet (8,839.2 metres). Reportedly, legend has it that the actual reading came in at exactly 29,000 feet, but surveyors tacked on an extra two feet reasoning that nobody would believe them otherwise.