The study of the causes of the disaster marked the beginning of modern volcanology with the definition and the analysis of the deadliest volcanic hazard: pyroclastic flows and surges, also known as nuées ardentes (Fr: burning clouds). Eruptions of a similar type are now known as Peléan eruptions. Among those who studied Mount Pelée were Angelo Heilprin and Antoine Lacroix. Lacroix was the first to describe the nuée ardente (pyroclastic flow) phenomenon.