According to a new press release, researches have developed a new methodology to monitor dangerous volcanic activity in the Andes Cordillera (Andean mountain system) where field studies are almost impossible to set.
Between southern Peru and Chile there are more than 50 active or potentially active volcanoes spread along 1500 kilometers. These volcanic systems are very difficult to monitor since they are located at altitudes of between 4000 and 7000 m.
In addition they have very abrupt slopes to reach them and are usually are covered with various layers of deep snow which makes almost impossible to monitor them for their activity. Field surveying of these volcanoes is extremely difficult if not impossible.
According to the press release, a team of researchers from the Institut de Recherche Pour le Développement (IRD) have worked and are still working together with researchers from the University of Chile (Santiago) and the Observatoire de Physique du Globe of Clermont-Ferrand, giving special attention to a volcanic complex known as the Lastarria-Cordon del Azufre. This volcanic complex has a surface area of 1600 km² and it is situated in the central Andes Cordillera at the border between Argentina and Chile.
IRD geophysicists monitored deformations currently occuring in the Lastarria-Cordon del Azufre complex using an new technique known as radar interferometry. This method utilizes the superimposition of two satellite radar images of the same geographical area taken at different point in time.
The differential signal between the images is called the interferogram. The interferogram of a region provides a way of detecting possible deformations of the earth crust. The value of the wavelength associated with it is proportional to the depth of the source of deformation.
In this study, investigators used data from an European satellite and produced 28 interferograms for the volcano system. The interferogrmas showed that a deformation (inflation) of a centimeter affecting the earth crust over the whole of the area studied.
This and other measurements could indicate underlying and undetected volcano activity for the Lastarria-Cordon del Azufre volcano complex. This activity combined with a change in gravity of the underlying layers of the earth crust could indicated that the Lastatria-Cordon del Azufre volcanic complex would be an area under the Andes mountain where the formation of large magma reservoirs could be in the works, making it the ideal situation for an eruption.
The researcher believes that this new methodology (if confirmed by more studies) could be applied to study volcanic activity where access is complicated, thus, making surveillance of these unachievable volcanic structures more effective
Satellite methods for monitoring volcanic activity in the Andes Cordillera. Press Release. Institut de Recherche Pour le Développement.