Melting into thin air

  • 29/04/1999

B etween 40 and 50 million years ago, the Indian subcontinent collided with the rest of the Asian landmass. This collision caused the Earth's crust to buckle and rise forming the Himalaya. The uplift of the Himalaya was a gradual process over a long period. As the elevation of the mountains rose above the permanent snowline, it was transformed into "the abode of eternal snow and ice' forming the glaciers. For over two million years, these glaciers have sculpted the Himalayan landscape and influenced the course of human history.

"Himalayan glacial snowfields store about 12,000 cubic kilometres of freshwater and have a significant cooling affect in the entire region,' says Bahadur. "The moisture-laden environment acts as a coolant for the region, thus creating an area of mega-biodiversity in flora and fauna.'

"These glaciers are, in turn, affected by various factors such as changes in the energy output from the Sun and anthropogenic (or human-induced) changes,' says Bahadur. But the receding and thinning of glaciers can be blamed primarily on the increase in emission of greenhouse gases.

Scientists had expected the five-kilometre-long Dokriani Bamak glacier in Himachal Pradesh to grow after a severe winter in 1997. Instead, it retreated by 20 m in 1998, compared to an annual average of 16.5m over the past five years. "This is a phenomenal melt rate,' says Joseph Gergan, a geologist at the government-run Wadia Institute of Himalayan Geology ( wihg ) at Dehradun.

But Dokriani Bamak is just one of several glaciers that feed the Ganga. The Gangotri glacier, too, has been receding alarmingly in recent years, says Bahadur. "From observations dating back to 1842, the rate of recession of the snout

Related Content