https://phys.org/news/2018-11-ice-age-years-minutes.html

Three hundred years of glacial history research

Despite the fact that explorers and scientists have been researching the glacial history of the Alps for almost 300 years, no one has previously succeeded in unequivocally identifying which climate developments led to large-scale glaciation. Questions remained about what conditions affected how the glaciers expanded, how thick the ice was, how often the ice sheet expanded and retreated, and what caused the ice to expand at different rates in different Alpine regions.