A brief history of the observation of the central area of piton de la fournaise

Abstract

The first road to reach Piton de la Fournaise was built in the 1960s, so until that point the central area and summit was seldom visited due to access problems. In addition, not all the visitors recorded their observations. However, since 1755 a number of reports have been written in various journals, or preserved as unpublished documents. Thanks to the recent availability of scans of old journals and documents on public websites, it has become easier to consult the original reports, and therefore to transcribe, as accurately as possible, their geological information. Drawings, maps and photographs at different periods are as precious as the texts themselves. Here we present an analysis of the historical documents to highlight the main volcanic and volcano-tectonic events that occurred in the central area of Piton de la Fournaise from 1751 to the first half of the 20th century. The best descriptions and documentation from this period come from the works of Bory de Saint Vincent and Alfred Lacroix, although numerous other accounts contribute to the reconstruction of the volcanological events. Beyond an obvious historical interest, the accurate analysis of the past behaviour of Piton de la Fournaise is of paramount importance in the understanding its functioning.