**Glacier changes have been documented since the 19th century. Illustration by Marco Heer.**

Internationally coordinated glacier measurements: a lofty challenge

Internationally coordinated glacier observation originated in Switzerland. Maintaining glacier measurements proved difficult during the two world wars. However, Paul-Louis Mercanton from Switzerland kept the research work going amidst the global turmoil.

Géraldine Lysser

Géraldine Lysser studied history and business administration and works in communications at the Swiss National Museum.

On 31 August 1894, 273 people attended the sixth International Geological Congress in Zurich. The honour of hosting the congress had unexpectedly been awarded to Switzerland three years previously when the Austrian delegation pulled out. Although Switzerland was respected as something of a geological mecca due to its landscape, there was no national geological body in Switzerland at the time – it was just a group of university professors who published information on the subject.

The start of coordinated glacier monitoring

The Commission Internationale des Glaciers – International Glacier Commission – was founded at the congress. It was the brainchild of Captain Marshall Hall from England, member of the Geological Society in London, François Alphonse Forel, Swiss professor and pioneer of the study of lakes (limnology) and Prince Roland Bonaparte, a great-nephew of Napoleon I, who had conducted research into glaciers in the French Alps. The prince’s wife was the casino heir of Monte Carlo and he wanted to use the inheritance to fund the commission’s work. The idea was to attain a better understanding of the factors that caused the ice ages through the systematic measurement of changes in glacier lengths.

**A measuring team at Rhône Glacier, 1899.** e-pics

Germany, Austria, Denmark, the United States, France, the United Kingdom, Italy, Russia, Sweden, Norway and Switzerland were represented on the commission, which was to collate glacier measurements from all the countries and publish them in a joint report. Forel was elected as the first president and he created the measuring guidelines. The secretary also assumed a key role as he was in charge of operations at the commission office and compiled the data for the report.

Professor Paul-Louis Mercanton of Switzerland assumed the role of secretary from 1913. The electrical engineer and Doctor of physics specialised in a number of areas and taught physics, electronics, meteorology and geophysics at the University of Lausanne. He made his name in glaciology by devising a special drilling technique, which he successfully applied to drill into the Trient Glacier at the north end of the Mont Blanc massif.

Paul-Louis Mercanton kept photographs from many of his expeditions. A group of glaciologists on the Rhône Glacier, 1918. — **Paul-Louis Mercanton kept photographs from many of his expeditions. Here is his photograph of a group of glaciologists on the Rhône Glacier, 1918.** e-pics

In the maelstrom of world politics

No sooner had Mercanton started work with Swedish geologist Axel Hamberg (the commission president) than the First World War broke out and placed international cooperation on thin ice. Researchers were not allowed to communicate with colleagues if their respective countries were at war. Fortunately, they were allowed to maintain ties with the Swedish president and the Swiss secretary as they represented neutral states. Nonetheless, only Canada, the United States, Sweden, Norway and Switzerland delivered data for 1914. The warring countries and Italy had more pressing issues to deal with than measuring glaciers. Hamberg and Mercanton issued written requests to the member states asking them to continue their monitoring and send the results – with moderate success.

**Photo of Paul-Louis Mercanton, ca. 1906.** German Röntgen Museum

International cooperation remained difficult after the war. Nationals of the former Central Powers were initially absent from the International Geological Congress and the glacier research was discontinued. In response, Hamberg and Mercanton affiliated themselves with the newly founded Hydrology Section of the Union géodésique et géophysique (union of geodesy and geophysics), thus ensuring the continuation of glacier measurements. They even managed to publish a report for those years where no official research took place:

Even during the war, there were competent and committed people in every European country with glaciers who continued the national monitoring work.

Paul-Louis Mercanton

Mercanton wrote three more reports as secretary before war put paid to glacier measurement once more. The following commission report was printed in Paris in the winter of 1939/40, but was then destroyed by the German occupiers. Fortunately, Mercanton had kept a first draft, which enabled him to prepare the data again after the end of the war.

Pioneering work in glaciology and radio broadcasting

Mercanton was responsible for publishing international glacier measurements up to 1954. However, his achievements extended beyond salvaging internationally coordinated glacier monitoring during the two world wars. He managed the Swiss Central Meteorological Institute in Zurich for many years, developed physical measurements of glacier thickness, was in the first party of climbers to ascend Beerenberg volcano on the Norwegian island of Jan Mayen, and a Swiss radio pioneer. He oversaw the installation of the “Champ-de-l’Air” radio station and was the first person in Switzerland to be granted a radio licence.

His legacy of internationally coordinated glacier monitoring also lives on: the World Glacier Monitoring Service, based at the Department of Geography at the University of Zurich, collects glacier data from all over the world. Given the current documented level of global glacier shrinkage and its associated consequences, such as water scarcity and rising sea levels, the United Nations has declared 2025 as the International Year of Glaciers’ Preservation. The first World Day for Glaciers will be on 21 March.