ICE TSUNAMI IN THE ALPS - Tambora: The Eruption that Changed the World - page 89

Figure 7.1. J.M.W. Turner's etching from 1812 shows Mary Shelley's view from the valley of Chamonix
toward the Mer de Glace. The longest glacier in France, it courses down the northern slopes of the Mont
Blanc range. Turner's image highlights magnificently the aquatic instability—and grim threatfulness—of
the “Sea of Ice.” (© Fine Arts Museums of San Francisco / Achenbach Foundation.)
The Shelleys were not alone in their dread of advancing Alpine glaciers in the waning
years of the 1810s. The members of the new Swiss Society for Natural Science, alarmed that
the widespread glacial growth of that decade had accelerated markedly on account of the
recent cold summers, turned their attention to glaciology for the first time in their annual
meeting in Bern in 1816. The following year they announced a new competition. A prize was
to be awarded to the scientist who conclusively answered the question of whether the climate
of the Swiss Alps had grown colder. In addition, applicants were required to provide their
observations on the growth and decay of glaciers. Three years later, however, the society had
received a total of one mediocre submission, a testament not to lack of interest in the ques-
tion but to its difficulty.
Enter Ignace Venetz, a gifted young engineer and montagnard from the Swiss canton of
Valais, who followed the Shelleys' footsteps along the tourist trails of Mont Blanc in the sum-
mer of 1820. 13 His impression of a glaciated Alps was as powerful as Shelley's, but his edu-
cated eye was better able to decode their ice-bound history through the specific evidence of
moraines. Buried beneath swaths of forest, or winding sinuously miles from the present gla-
cial rim and snow line, these riverine piles of rock and earthy debris marked the ghostly out-
line of the massive glaciers of the past. In his seminal paper of the following year, “Mémoire
sur les variations de la température dans les Alpes de la Suisse,” delivered to the Swiss So-
ciety, Venetz laid down the founding principles of Ice Age theory. Only historical variations
in temperature could explain the changes in glacial extent, he argued. Furthermore, these
changes in climate were extreme enough to have once submerged this region of the Swiss
Alps beneath a vast sheet of ice, whose subsequent retreat under warmer temperatures had
left behind the moraines and striated rocks as a kind of glaciological signature.
The theoretical possibility of large-scale glaciation had been suggested intermittently over
the previous decades by scientists in various countries, only to be ignored. Venetz was the
first to make a serious case based on geological observation, and the first to make the neces-
sary link between glaciation and climate change. Venetz's career as a pioneering glaciologist
was marked by a lifelong devotion to on-site study in the Alps, but also frustratingly few pub-
lications. It is possible, nevertheless, to show that the evolution of his theory of the Ice Age,
and its breakthrough revelation, occurred in the course of a specific Swiss crisis during the
Tamboran summers of 1816-18, when the multiplying spin-offs of sustained climate deteri-
oration threatened lives and livelihoods across the Alps.