First testing of a volcano Doppler radar (Voldorad) at Mount Etna, Italy

Abstract

A medium-power (1 kW) Doppler radar of limited weight (110 kg) and working in the UHF band has been developed for active remote sensing of volcanic eruptions. Named Voldorad, this radar is designed to monitor eruptive activities of variable magnitude at medium distance range (~0.5-5 km), in any weather condition, and fills the gap between low- and high-power radar or sodar systems previously tested on volcanoes. Voldorad was operated for the first time during an eruption of Mt. Etna on October 11-12, 1998. Doppler spectra recorded at 1 km distance from the vent reveal powerful echoes during the eruption paroxysm (lava fountains), which gradually decreased along with declining activity. An average vertical velocity of 80-87 m s-1 is inferred for the eruptive jets.