Scientists re-create the life of a glacier from 1874 to 2100

Washington, Oct 30 : Scientists have developed a numerical model that can re-create the state of Switzerland's Rhone Glacier as it was in 1874 and predict its evolution until the year 2100.

This is the longest period of time ever modeled in the life of a glacier, involving complex data analysis and mathematical techniques.

Researchers at Ecole Polytechnique Federale de Lausanne (EPFL) have designed the model.

The Laboratory of Hydraulics, Hydrology and Glaciology at ETH Zurich has been a repository for temperature, rainfall and flow data on the Rhone Glacier since the 1800s.

Researchers there have used this data to reconstruct the glacier's mass balance, i.e. the difference between the amount of ice it accumulates over the winter and the amount that melts during the summer.

Now, led by professor Jacques Rappaz from EPFL's Numerical Analysis and Simulations group, a team of mathematicians has taken the next step, using all this information to create a numerical model of glacier evolution, which they have used to simulate the history and predict the future of Switzerland's enormous Rhone glacier over a 226-year period.

The mathematicians developed their model using three possible future climate scenarios.

"We took the most moderate one, avoiding extremely optimistic or pessimistic scenarios," explained PhD student Guillaume Jouvet.

With a temperature increase of 3.6 degrees Celsius and a decrease in rainfall of 6 percent over a century, the glacier's "equilibrium line", or the transition from the snowfall accumulation zone to the melting zone, rose significantly.

According to this same scenario, the simulation anticipates a loss of 50 percent of the volume by 2060 and forecasts the complete disapearance of the Rhone glacier around 2100.

"It is the first time that the evolution of a glacier has been numerically simulated over such a long period of time, taking into account very complex data," noted EPFL mathematician Marco Picasso.

To verify their results, the mathematicians have also reconstructed a long-vanished glacier in Eastern Switzerland.

They were able to pinpoint the 10,000-year-old equilibrium line from vestiges of moraines that still exist.

The scientists' work will be of interest not only to climate change experts, but also to those to whom glaciers are important - from tourism professionals to hydroelectric energy suppliers.

According to Picasso, this numerical model could be applied to the polar icecaps.

"Mathematics and numerical methods have an important role to play in our society," he said. "They allow us to simulate with great confidence a large number of environmental phenomena," he added.

ANI