The microclimate of valley glaciers

Glaciers have fascinated mankind throughout history. Glaciers look solid and robust, but observing them for only a couple of years shows that they are dynamic and change shape all the time. The lower glaciers come, the greater the contrast with the surrounding landscape. Many glaciers in the world enter pastures and forests. It is not surprising that laymen, artists and scientists have reported on the behaviour of large valley glaciers. A wealth of information on glacier fluctuations in historical times has thus become available, notably from the Alps, Norway and Iceland. Combined with the results of geomorphological studies it has become possible to reconstruct the history of an ever growing number of glaciers. More systematic mapping of glaciers started only 100 years ago. The most comprehensive data set is related to length variations. It is relatively easy to make annual observations regarding the length of a valley glacier. Volunteers from Alpine clubs and other organisations have played an important role in compiling an impressive data set (World Glacier Monitoring Service, University of Zürich). In recent years the possibilities to map and monitor glaciers have increased enormously, mainly due to new remote sensing techniques.