Alpine ice sheet

Context

For nearly 300 years, montane people and early explorers of the European Alps have learned to understand that glaciers slowly flow downhill by gravity and thereby reshape the landscape they lie upon. In fact, the European Alps are the cradle of pioneer glacial studies and one of the regions where moraines, erratic boulders and other geological markers of glaciation are most abundant and well-studied. About 25 000 years ago, glaciers filled most valleys in the Alps, and even extended onto the plains that are now parts of France, Switzerland, Italy, Austria and Slovenia.

Glacier modelling

In this project I use the Parallel Ice Sheet Model (PISM), an internationally-developed computer model that contains knowledge of glacier physics based on modern observations of Greenland and Antarctica and laboratory experiments on ice. With help from the traces left by glaciers on the landscape, my colleagues and I attempt to model the evolution of former Alpine glaciers in time.

The simulations run on the Swiss National Supercomputing Centre (CSCS) Piz Daint, the fastest supercomputer in Europe and among the fastest in the World (see TOP500). In a study recently published in the open-access journal The Cryosphere (doi:10.5194/tc-12-3265-2018), we present a detailed reconstruction of Alpine glaciers multiple cycles of growth and decay from 120000 years ago to today, a period that spans the last glacial cycle (see ETH News, NZZ).

Modelled last glacial cycle ice dynamics in the Alps (more videos)

Outreach

Visualizations of the results were temporarily displayed at the History museum of Wallis in Sion, during the 5th night of images in Collombey and Naters, and are permanently exposed at the Archaeological museum of the Canton Solothurn in Olten. The simulation provides a detailed picture of glacier growth and decay, but discrepancies with the geological data remain, and more observations are needed to validate the accuracy of the results.

Zoom in and explore different ages. Best viewed fullscreen.