Current Monitoring

            Volcan Villarrica is considered to be one of the three most potentially dangerous volcanoes in Chile by the Southern Andes Volcano Observatory (OVDAS) based in Temuco, Chile, about 90 km Northwest of Villarrica. Because of this, OVDAS has been working to improve and expand monitoring of the volcano, though progress has been slow. OVDAS currently operates two seismic stations for Villarrica at 4 km and 23.5 km northwest of the main crater, repectively. Seismic data is sent to the local Villarrica observatory in real time from both stations, where it is then forwarded to OVDAS in Temuco hourly. <-- link to site.

             Since 2001, SO₂ monitoring, using Correlation Spectrometer (COSPEC) measurements, has expanded. Villarrica's active lava lake has made it fairly easy for scientists to monitor the volcano's gas levels, though none consistently besides SO₂.⁸

        OVDAS has also installed base lines, dry tilt mirrors and prisms around the volcano in an attempt to monitor possible deformation of the volcano, which is due to the injection of fresh magma in the volcano's conduit and is considered to be a fairly accurate predictor of eruptions. ¹⁰

           Because Villarrica contains an active lava lake, it is a very consistent source of volcanic gases such as SO2. Because of this, research in the practices of monitoring SO2 levels has been performed on Villarrica. This research has led to the improvement of SO2 monitoring through digital imaging. A camera utilizes a bandpass filter to collect photons in the ultra-violet (UV)region where SO2 only absorbs UV light. Then the SO2 level is measured by  imaging "calibration cells "of known SO2 concentrations.¹²

           Since Villarrica is considered such a dangerous volcano, the monitoring practices currently in place are insufficient. According to the National Volcano Early Warning System's guidelines, Villarrica is considered a VERY HIGH risk volcano, meaning it should have between 12 and 20 seismic stations on and around the volcano as well as a network of GPS stations to monitor deformation and a series of instruments for thermal imaging as well as monitoring the volcano's gas levels. The System also stipulates that all this monitoring should be done in real time. Obviously, Villarrica's current monitoring network needs to be upgraded and expanded, as OVDAS is currently working on, with the installation of more seismic stations on and around the volcano.⁸

Fig. 7.3

A diagram relating how the two seismic stations send data to the local monitoring station at Villarica, where it is then transmitted to OVDAS.