Active Volcano Monitored with Spectra Geospatial SP85 GNSS Receivers

To improve safety for the island’s almost nine hundred thousand residents as well as Indian Ocean rim communities and to conduct scientific volcanology research, the Piton de La Fournaise Volcanological Observatory (OVPF) is charged with monitoring the volcano’s activity.

OVPF’s post-eruption monitoring includes quickly characterizing, within two days, the resulting large-scale spatial deformation that has just occurred. Following each eruption, which average two per year, two teams from OVPF, each equipped with a Spectra Geospatial SP85 GNSS receiver and a MobileMapper 50 data collector, are deployed to 79 established locations. At each location, marked by a steel rod embedded in the lava, the teams take fast static measurements. Using three minute, one-second sampling, 4-cm vertical and 2-cm horizontal accuracies are achieved. These results are integrated with data from 24 separately equipped permanent stations to model the magma’s path. “The aim of these observations is to improve our understanding of the magma plumbing system to better anticipate eruptions,” said Aline Peltier, OVPF volcanologist and geophysicist.

Topo-Mat, a Spectra Geospatial dealer with an established presence on Réunion for more than five years, worked with OVPF to choose the most appropriate instrument for the field survey teams. The SP85 meets all the requirements for work in the volcano’s challenging environment. It is compact, light-in-weight, easy to use, and its all-day battery life through hot swappable batteries allows for an uninterrupted workday. The SP85 is used in combination with the Spectra Geospatial MobileMapper 50, an Android 6 GIS data collector that offers state of the art smartphone capabilities. OVFP uses Spectra Geospatial Survey Office software for fast, easy post-processing to enable survey results to be quickly completed.